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B . Scho T . rehclaW J. ambchW W. eisW S . Yam d (KE , K. ~ k a z Y

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Laborty,

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Germany), Mainz,

Germany)

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S . Sugimot

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1x

CONTES

v

ecaf rP gni epO

.I

INTRODUCTION Hadrons

adres

ot miguS

.S

and

1 IX

- from

T . adustaH

QCD

11.

MESON Vector

op

IN meson

R.

p aR meson

K.

and

J.

.111

production

Fries

,am yuraM Delta The

H.

,ikaz m Y

H.

M.

fo

A

fo

SYMPOSIUM

with

weiv

ME

probes 3

-

MEDIUM dileptons

and

in

heavy-ion

12 colisn

29 fo

q5

H.

spectroy

T . ,imak ruM S.

in

,atiroY

T.

adihsoY hadronic

H.

,ikag maH

Sekimot,

T. ,aduS dna

R.

at

M.

,otuM H.

dna

HADES

IN nuclei

by

exita on

ihc ak oK

M.

with

)noitarob l oC

KE at

meson

,ihsa nuF

,ikas S

0.

,adum Y

excit d

rebuH

THE

nucles

T. J . ,igas K H. Y.

Shimzu,

G.

the

J . ,abihC T . ,atihsapiM Ozaw ,

e (HADES

TO

J . hcabm W

RESONA CES resonac

in nuclei J. abihC physic

mediu

.S

pair

NUCLEON

)53 1( s

NUCLEAR

in in

H . ,oy’nE S. , a r h i M ,ihcam K. H . ,ak n T 523E )noitarobal oC

physic

point

am yuraM

Nuclear

Lepton

nuclear

D. ,otaS Y . arumihsoY

T.

ihsan K

Itoh,

,ikuraN

T . ,urab T

M.

Ishino,

39

No-

(KE -PS

K.

49

AND K.

M.

GSI

NUCLEI Kinoshta,

M.

leir ,

T.

T.

,adukO

,aw k yiM

RELAT D

TOPICS H.

,iustaM

H.

,onukO

16

T.

76 proces 57

X

The

neutral Il-T.

Phot neutron ton

scat ering

Nuclear

IV.

Subthres old

H. M.

dis ntegra io

K.

Retrospect Spin-orb t

section laser

Y.

H.

and

Paryev

S.

polariz t n Yamamura, W. fo

E.

Paul

0.

Hashimo

H. K o h r i , Franz, K . Matsuoka, J . Nak no, Rusek, R . Sut er,

SNOITALER C Suda

Yonezaui ,

Toy kaw

Glock e as oci ted pros ect

split ng

kaon

phot r duc ion

T.

Fuk da,

E.

Saji,

H. T.

M. Tam gaw ,

of

87 Ohta, 93

coliders

L.

Noumi, A . Sak yuchi,

Gun,

on

T.

Mart,

on

H.

and from

C.

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the

701 13

nucleo

the

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19

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at

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reactions

heavy-ion

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producti n

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fo

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phot ns

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f o invers

means

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meson

C.

Kaon Miyag wa,

to

S.

yb

Akimune, Ohgaki

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K+

strange s and

eB’

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thres old

10

fo ni

near

ielcun

aspects

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prot n

virtual

thres old

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H.

and yb

on

near

the no

induce

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H. and

on

Jeong measur nt

phot ns

Pshenichnov

Ya.

T.

T.

M.

Maeda

E.

N-

Phot dis ntegration

of

phot production

PHYSIC

phot production

T.

Physic

V.

Utsunomiya, Fujishiro,

STRANGE S

Phenomlgica Hyperon

and cros

I. A . Kaon

pion

Cheon

521

physic

R.

E.

S. M i n a m i , H.

Chrien, Hay kaw ,

H. Outa,

H.

AND

fo

Tamura, 3He

P.

R.

FEW-BODY

731

Saw fta,

and

K.

Y.

Paschke,

*He

K.

M. Miyake, Tanida, at

G.

Eugenio, Khaustov,

P.

Y.

Shim zu,

TAGX

PHYSIC

P.

Mori, Pile,

T. L.

Tang

T.

Kishimoto, Morikubo, B. Q u i n , M . Sumihama, and L.

147

J.

Fkan lin,

K.

A. Yuan 15

xi

nucleo

Phot nuclear

cros forces

G. Quasi-de t ron Two-nucle Quark

VI.

The

NUCLEON

picture

Hirenzaki,

P.

Grabmayr

E.

substructure Lomon

prot n

A.

Spin

structure Y. Sakemi

First Drel-Harn

double

VI .

W.

Experim ntal

W.

Yam guchi

Nuclear

Y.

J . Kas gi Laser

T.

M.

el ctron

Y. Matsuoka, Y. Ohashi, Sak guchi,

isobar

and

of

A phot n

J. K.

Ahn, K . Hicks, T . Kishimoto, T . Mibe, T . Ooba, T , Sas ki,

Tomsiak

form-acts

BY

HIG -EN RGY

391

in

EL CTRONS

el ctrop du i n?

02

HERA

at

K-A

relativ

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HERMES

yb

29 the

yaw

to

test

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beams

at 1.2-GeV

247

Col aboration) parity hig

enrgis

STB

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ring

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ukoh T-SNL

a t Spring-8 Akimune, Y. Asano, W. C . C h a n g , S. K . Imai, T . Iwat , T . Ishikaw , H. Kawai, N . Kumagai, S . Makino, T. Matsumura, M . Miyabe, Y . Miyachi, T. Nakano, M. N o m a c h i , .H Ookuma, M . Ooshima, .C R a n g a c h a r y u l , D. S e k i , H. S h i m i z u , Y . Sugay , .M S u m i h a m a ,

.H

1

239

and

with facilty

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exp rim nts phot n

deut ron

on

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the

thre -

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whom

measur nt

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71

reactions

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L.

role

Mainz on

studie

E.

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STUDIED is probing

nucleo

at test

K.

charged- u nt

the

the

phot dis n egrat o Kume

efcts

who

rule (GDH-

polarized

4He at

phot n,

Hersman of

physic

polariz t n

physic

Hot a, Fujiwar , Kim,

the

of

FACIL T ES

- esU

Umemoto

and

Meyer

F.

STRUCTURE

neutral-

NEW Few-body

Y.

and

and

D. Efros

V.

for

and

sum

sy tcm

exp rim nts

and

Nag no

thre-nuclo

Leid r mn ,

emison

Levy

K.

of

W.

Orlun,di

S.

High-Q2

section

265 27

Da t e , N.

A.

.2

1

xi

T. ,ar henoY MUSE

T.

yram uS

H.

muisop yS

tsiL

H. T . atiroY

,am yo T

Katym,

tcejorp

ta

the

fo onukO

sympoiu

NEKUF

,aw koy T

K.

dna am yur M

A.

M.

IR

maeb

Yosi dna

Waki, C. yrotcaf

W.

Wang,

.S

C. Wang,

K. 27

M.

Waksugi 285

29

margorp fo

stnapic r

295

1

.

Xlll

Adres

Openi g

Ladies

and

the from

was

On

partic pants

thre

The

physic.

Synchrot n

our operation. wen to topics Probes. through stay

es ntial

steps

toward

in

fo

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this

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ew activ es, faciltes sympo iun

Thank

built

role goin resach

pres nt

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for

fruit l

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of

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ew

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contribute

sympoia

27th

ni

site this

labor t ies. Nuclear

with n t.a

of

country

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at

Physic

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I.

INTRODUCTION

OT

THE

SYMPOSIUM

ThisPageIntolyLfBk

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Hadron K.

and Maruym

02

Hadrons

Nuclear

Elsevir

ecn i S

and

T.

with Okuno

B.V

(Editors)

Electromagni

lA

sthgir

nuclear

point

Probes .devr s

sci yhp

fo

3

ME

with

view

probes

-

Hatsuda

Phys.

Dept., After

physic

sci yhP H.

QCD

from

-

and

tral dens observal

of

functio s

Kyot

a riefb in-med u

mediu .

Univ., introduction in

in

Special

both

of

hadrons

lat ice

60 , Kyot

emphasi

theor tical

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are

QCD,

Japan cur ent

discue.

and

si

and

crit al exp rim ntal

put

They

fluct a ion the on

problems

are

in in-medu

QCD studies.

QCD,

of

selctd

the

spectral

chiral

QCD

orde

functio

topics

sum

par met r

whic

on

rules, si

the spec-

the

in

yek

INTRODUCTION 1.

interaction.

Quantum

Chrom dyna ics The

QCD

action

(QCD)

can

m being the quark mas , D p si t h e covarint derivat . This action has be n wel-stabihd inelast c lepton-hadron scat ering dient her si t h e asympto ic f o the QCD run i g ouplingc scale of a given proces) ncreas:i

scale interaction perturbative car ied (K

wol a orde

inter s g 4.151

-

par met r

(DIS) fredom

(llN,

and

N,

Nf

among

an lyse lso,A p >> AQcD), su t o t r e a t [3]. (Even phenom a

are whic

the quarks

out.

at at

the

very

the extr m ly

takes

and smal

sy tem such

as

f o ev rything

[l]:

in

strength

tensor

y b igh and e+ QCD [2] cr,(~) sa whic

enrgy an ih l t o K

of exp rim nts

leads

(reno maliz t n

to

the

physic

the

into

f o strong

gluon such

hadrons.

the

logarithm c

,:A

dleif as

point

A yek

the decras

the N

and ingre-

dep-

typical

+... number

with

theory

dleif

of

consta

ln(K2/AQcD)

2Nf) -

is t h e

si t h e

r721 =

wher

writ en

,:G

wher

OdK)

be

hig

of

a value gluons

ap ro iate as as

around

run i g

rol c becom

temperature

the

hig

and

spati l

T

20

kaew

factoriz n (K

coupling

no -i terac ng

rovalf

a,nd confiemt

p,

respctivly, MeV.

N

howevr,

consta

of

at

Due

the

T > ), ,A gas

to hig

of [4]

enrgis

hard quarks the

as and

l ew sy tem

the

and

asympto ic and

and and the

as rol c

AQCD

the hig gluons

stil

the

and soft chemial

Deeyb supercond tiv y

may

fredom,

the

si t h e sy tema ic

part in

QCD

wohs

the

screnig

poten ial

can

the be

tsewol

some

4

At gluon

wol

en rgy

self-int rac o s.

scale,

the dynamic l QCD vacu m ap ear from f o meson The cur ent

(1)

QCD This

Any efct

(3)

Interplay part:

Her actions from a uniq e

are

QCD

be

an

from

arbitra y

to

fo

the

theory choies.

q , Q, A

the

must field

predict on:

integra ion

fo physic

fo Howevr,

rew it en to

the

explict namely

ther

si

hadronic

yb

(n, action so

both

A dep n c that dZldA

writ en

at

confiemt

to

hot

chaleng.

ew the

the fields

evig

quark

exampl ,

should

(e.g ,

in =

0.

ni whic parti on

terms

out below. pions

in

hig

colisn

the

and

nucleons),

the

woh rof

the

thes

It

us

on

si

with si

can

a wen also

woh

the

density.

proces.

and

and

into

a chalengi

mat er to dynamics

and

make

obtain

soft

devlop-

ins ght

nuclear

and

the

functio

quarks

then

efcts

CERN

eq.(l) same

obtained

parti on

and

no -triv al exist nc

at

QCD

part no -pertu ba ive

no-liear

categori s: baryon

the

ful

frequ ncy

gluons

[6].

exp rimental

the

One

and

hig

start

rep s nt

hig

at

fo

plasm .

amplitude

to

enrgy

evig

mat er.

to

strong

thre

scat ering

Recnt

alwys

the

quarks

gniwol f

star

consider

eq.(5)

an lytic phenom a

quark

colisn

syaw

quantum

relat d

or

hard

informat

fo

fo

the

f o the informat

dens us gluon

many

. . ;. A ) ]

ful

physic

extract

and/or could

wohs

heavy-ion

mediu .

integra ing

the

to

are

and

hot/dens

writ en

whic

temperature

soft

woh

roF

N,

fo

a result

into

hig

are

sevig

as

star

the

becaus

whic

[is;, action

emrg

the

and

nucles-

and to

ev rything,

This

A,

exp

efctiv

QCD

the

and

insde

sa ultra- el tiv s c neutron

fo

a combinat

and

exp rim ntal

in

vari bles.

.I

[d.irdN.

such

in

dleif

cutof

sym etry,

physic

hard si lways them and

transit on

equival nt y

efctiv

physic

hadrons

are

it si stil difcult eq.(l), they are fundame t l lsoa f o the atomic uclei.n in QCD may be lasifedc

hadrons

fo

the

field

is t h e si t h e have

the

the the

hadron- ucle s

si

chiral

Althoug

efcts

exampl s

and

proces factorize

problem a phase problems.

fo

condit s

to

to

with

revo

fZS feS

action isue

theor tical

pro e ti s

-

while

woh

pro e ti s

Since the above in difernt integra ion QCD:

can

QCD

baryons,

betwn

physical

The ments the many-bod undergo s

This above vari bles below.

physic

Typical

breaking

a t extr me si rel vant and lsoa

BNL,

(2)

the

and

structure.

no -pertu ba ive

at ach after

the

gluons

change

fo

eq.(6)

. terms should

fo

fo the functio

the low-enrgy

ygren -wol be

caneld

hadrons. si i n d e p n t

by

quarks the

Both

fo

and

A dep n c A and

efctiv

in

gluons, sevig

5

So

someti

far,

a most

yb one rules

numericaly

enrgy

the gen ral

exp riments.

has whic

Wilson After

and

taking

have

operato

wher

this reviw

par l e

yb

numerical scale

A

The simulat on

great

idea

1985,

In the phenom a universal

a posiblty crit al

ambiguo s

the

point meson

In

of

Among view. Im(

the

in

scaling at

just gos,

QCD fin te

below it

l/a has

in

expansio ;

hadronic

si n o t (the

sym etry one

with

we

at then

car y

si

the proges

hadronic

a yaw

and

l iw

it makes

focus

al.

a typical

out

a being

in

devlopmnts.

sym etry

and

theory

considerabl

rep oducing

rema ks,

practi l chiral

may

descript on

such

quanti es

as

phase

meson-bary

deconfimt

as

theor ical the

a signature recognizd such

both

studie of

has

In breaking

det rmin the lat ice

the

quark-gl on

spacing).

in

pro e ti s

esu

actual

recnt

of

the

par met rs of

years

]9[

ap ro iate

in-medu

ap licat on, scale)

the exampl

integra o

the on

l iw various

shift transit on

hadron

evah

el ctro-magne ic

the

as

mas-hift

first

on

of

two

=

the

i Im

to ls evitc f

and

[dqdqdA] This

one

construc

this

in

sort

[7].

in

SZf

fI

eq.(5)

si t h e l a t i c e [8]. QCD sum based on t h e windo of are valid

are

descript on

hadrons

also

transit on

the

that

hadrons

exp rim ntal

imag n ry

J

point

cur ent

d4zeiq

functio s is t h e part (target

formati n

also

lagr n i s a direct

in

are

of

pJTI

the

genralizd

[13],

width-broa eni g

exp rim ntal y, devlop enorm us,

dens

coneti

of

in

in

the

gniwol f

the

Matsui

fo

measur nt

the ideas

not the and

quark-glon

Pisar k models

dilepton

relation

discue functio s

1982,

thes howevr,

in

elihw

In

scalr-io exampl

is, has

observal

EM most

studie al.

spectral and

and

wohs

hci w et

the

pmeson of

a typical

has

80s.

early phenomlgica

the

as

Rho

er w refncs

in using

of change

mase, ben

Hashimot

the

FOR

various

defin

and

of

theor ical y

started

mas

number meting

we

with

Brown

J/S 1986, In

temperature

the

[ll].

T.

weN

hadrons finte

I have

chiral

the J/S ylediw

fo

saw

hypot esi

observ

and of

at

FUNCTIONS

eW

TJ )target

hci w

both

in-med u

SPECTRAL 3.

yb

12(

theor ical

t o be s t u d i e i n ref.[1 ] QCD sum rules [15], [17] and so on. Since fo t h e recnt irschegH In t h e next section, the vector chan el implct

product

to

Kunih ro

cq

the quanti y

computer,

recnt

of modifcatns

Heavy

transit on and disap e rance

pertu bation

but GeV

HADRONS

The

hadron out

chiral

suce

IN-MEDIUM

2.

1.2

=

A large

duality).

introduct ry

some

si e x a c t ,

4rfT dewol a N

f eS

a big

QCD

(quark-hadron

argument

set

dynamic l yet

to

of

hadrons

the mas

discue

and

pointed

a meson and

Satz

proved.

plasm

) are

crit al

prosed deconfimt prosed

near

a

J/S

shift

of

the

[14].

(instead relvant

althoug it saw in s09 uchs a s t h e in-med u [16], quark-meson ouplingc I l iw ref t o t h e Proce dings mat er [18]. of t h e spectral functio t o il ustra e i t s importance.

[lo].

the of

alre dy model in

CUR ENT ni

importan cor elati n

this (z)

QCD,

Jv(

the

0)

I target),

one

time-ord (the

from

spectral

the

exp rim ntal

cor elati n functio )

functio as

point

fo

(7)

6

wher

/target)

is a given

many-bod

state

,J

and

is t h e

el ctromagnetic

cur ent

QCD:

in

(8) the al probes cur ent ables.

The the

physical

complet

sta es the

Now,

set

J onto

excit d

let

us

an ih lation

s =

For the si w r i t e n

For

dN(w

f I one with

whic

quarks

$q

can

A being

gives

spectral Then

the

matrix

many-bod

example

the

into

vacu m

hadrons

the

vacu m

(e+e-

time-lk

si

from volume

is

the

vacu m.

Ther fo

phot n

Bjorken

the

the

vari ble. nucleo

hot

+

(plasma

Namely,

the

from

N

y*

probing

the

cros

the

through t-

is the

X), +

is directly

one

exp riment.

it

external observ-

section

this

Her

structure

plasm

cros

in

inserting

with

the

*y(

yb

Im(TJ )target

X), 4

target

the

is

*y

+-

prot n

probing

dileptons

fo

clear

f o contribu ons Jltarget). by a c t i n g

target

section

the the

+X),

is space-lik

the

emison

Im(TJ )th,r al

( c

w2

and

the

zBj

are

con e ti

el m nt,

target

becoms is a s u m the state is obtained

with

whic

direct

with

ew

Im(TJ )target functio

el m nt

sy tem

matrix

through

< 0 and of

spectral

the

proces

= .;9-

functio

the

fo

> 0 and

phase- c

=

time-lk

fo

some

the

unit

Is ) d4xq,.

with or the 4.

emis on

per

$q

Ther fo e,

phot n. the

target.

the

J s.

as

Q2

rate

no -va ish ng

to

fo

de p-in last c

wher nucleo . virtual

3.

state

the show

wher structure 2.

fo

betw n

having

e+ -

For prop rtional

.1

meani g

phot n car y

gluons.

q2 -

whic

a nucle s,

an

> 0.

information

out

the

Her

Thus

ev ntual y the

folwing

the are

ew

cros

on

probing

section

the

hypot e ical

vector

target

the

decays

is w r i t e n

meson

si t h e into

thermal

hot

dileptons. exp riment

plasm

as

pro ag tion

distribution through

the

?*(time

like)

in

mat er.

emis on

fo

+

hadrons

A 4

fo

X

5.

In

hadron-hadron

B

from also

X)

whic

the

Now,

I l iw

one

production

By

what

QCD using mediu

kind

up

sum the

at

the

can

probe

f o theor tical f o them

two

as ociated

Drel-Yan

with

proces ,

the

mechanis

at

of

the

know

Im(TJ ),QcD is dep nd on t h e mediu by t h e the direct lat ice exact spectral functio This QCD sum spectral shift as ~91.

Lat ice

lat ice

t h e properties the quench d % with 5-10 in ac es ing the lat ice conti ua on no -triv al Rec ntly QCD data

can

by

and

density

en rgy

inter al of

the

a production the

cros

structure

time-l k

the

the

know

l ew

of

section

fo

phot n.

only

dynamic l

is evn using

simulation

the at empt

the

imag n ry

the

deriv

car ied clasifed maxi um

functio

The

theor m

two-p in

cheking

have

l ew

on

quanti es

to

as

the

spectra out

extract

to

the

rema k ble

the

mase for

time as entropy

wol Ther fo e, in t h e be n

time-l k

the

in

discret t o the a n il-posed spectral

of

cal u ted

hand

mediu

phot n

is w r i t e n

projectil

the

Minkows

Howevr,

+

(A

as

and

the

prog es fo light

real functio s

problem.

for

[15].

the the

They

target

and

can make

field

phase meson in

the space,

in

rec nt

(SPFs)

the has

the

fo

baryons QCD

hadrons

reported

product

time.

such

does

or

constraints rules predict ons

in

pos ibly

on

eq.(14).

measur ments

had

In

cal u ting particular,

agre

is higly [21].

the

on

an lytic

from

by

with n

difcultes

The data

not the the

fo

cal u tions

for

lat ice

functio folwing

thus

estimated

years

noisy be n

and

be

theory

becaus

QCD?

operators

sum

some

transit on.

and

lat ice imag n ry

operator spectral have

theor m

some

the

making efctiv

in

QCD.

loca

pertu ba ively eq.(14)

can through

using

(MEM)

for

invar nt

QCD

points time

functio s

lat ice and

rules

fo

fo

of

functio

spectral

and

gau e

one usefl

valid ty

method

sum

side

temperature/density

the

rules

is t h e

pro e ti s [20].

study

sum

a set temperature

fin te

left

and have

as

be

used QCD

Un

spectral

simulations exp rimental

at sum;

be

coefints,

simulations. Im(TJ )t,rg,t constraints a s for

rule

for

can

and

weightd

structure.

en rgy QCD

QCD QCD f o hadrons QCD

from a first

the

can folwing;

one

Wilson

target wol

to ls

the relation

distance,

fin te

the

is t h e

in

selur

disper ion

short

form

nC

wher as

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as

TO LS pick

expansio in t h e gen ral

4.2.

colisn

such

THEORETICAL

4.

4.1

+

*y

+

lat ice MEM

8

si a m e t h o d Carlo simulat on phy and 4.2.1.

posit n

whic astrophy ic

The

Basic

Euclidean

D(r)

idea

s

=

at

has in

zero

(Ot(r,

ME

K(T, Monte

N,.

A(w)

fo makes

Carlo From

with

data

the

as umptions

difculty its si

MEM

the

lat ice sum arize can theor m,

condit al be

si much

si

with

L

simulat on

this conti u s standard

on

= -

1

Bayesin on

al

the yb

) .,r(O

operato

A(w)

and

si S P F K(T, w ) si pro ti nal tA eroz temp ratu e

w:

likehod

Bayes yb

vari t on

are theor m:

of maxizng

second

and

quantum

its

in

Monte

crystal og -

spectral

decom-

(or

someti

to

(T

caled

the 0) =

the Fourie

in

the

image),

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conti u m

hci w of

a

lim t,

X

si a typical of degrs and its made. inferc

nevig

and

the we

prio of

knowledg.

discret ned

il-posed vari nts of

MEM

to

reconst u

of

si most

=

inap l c b e

proba le

The with

P[AIDH]

to

be

reliabty

a method proba le

to

egamz image

proba il ty resp ct

wher

reconstruc ed.

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points

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problem,

fredom

the

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f o temporal

set

number

unles cirumvent

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strong

toge h r

with rof

DH],

the

A(u).

to

[23]

5

.T~/U

functio

the

wher A(w)

P[AI of

0 5

spectral

obtained

yB

P[XlY] wher

the

Bayes

this

nevig

H

result

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functio ,

- DA) zT.(

C(D(T2)

anlysi

shape

sta ist cal

number

on

noise,

This

w. the

spectral

defintos

the

D(r2)

sta ist cal

than

the

proba il ty

P[DIAH]P[AJH], (P[AIH])

P[DIAH]

varible likehod

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[2 ].

:0

the

ni

(17)

kernl mas

provides

with

D si o b t a i n e d

data chekd

roF

data smaler

based

P[AIDH] wher

an

problems

reconst u i

=

The

with

of

simlar image

(18)

throug

reliab ty

frequncy,

rof

and

D(r)

read

0 ) d3a:

aplied physic,

exp(-rw). =

w)

mat er

functio

Z)O( ,

r > 0 , w si a real si ositvep semi-d f n te. ref osnb pro ag tor wher

sucefly

[2 ].

fo

cor elati n

thre -mo ntu

be n condes

C;l

likehod standard

x2 -

(D(T,)

functio

(the

si a d o p t e d ,

prio namely

proba il ty).

P[DIAH]

;2 =

exp(-L)

DA ( . j ) .

ZJ

si a normaliz t n D A ( ~ z ) si x N covarine used in t h e

,2

difernt

and N be

o

T S,

positve

Axiomat c

S

and =

nroS

m

distr bu ions

)w(a[

as

the and

ME

cor elati n

factor. matrix

an lysi .

it s i esntial

constru i

such

P[A(Ham] -

=

m(w) -

D( T % ) si t h e lat ice functio efind of t h e data with N The lat ice data t o take into counta sa l e w a s intu ve as S P F , the prio proba il ty ;2 exp(aS). er H S

A(w)

gol

131(

-

dw*

yb evah

data being

avergd

the the

monkey si t h e

genraly

right

the

number of-diagnl

informat

can

argument

revo

hand

fo

strong be

side

gaue

comp ne ts writ en

entropy,

temporal cor elati ns [24]

configurats of

with

wohs

(17).

C

points

par met rs

that,

fo

si among

an

C.

for

to

9

si a normaliz t n

,2 positve In A

the

and

functio

a:

Aout(w)

sta e-of art

the

ME

[2 ],

si Q

default

)w(,A

a real model. output

the

P[ajDHm]

/AY(w) =

wher

factor. caled

and

positve

par met r

Aout image

and

is nevig

yb

m(w)

is

a weightd

a real

and

averg

revo (20)

d ~ ,

si o b t a i n e d

yb

maxizng

the

fre-ngy"

"-

Q~QS-L, rof

a given

dicta es and that degrs

(21)

the

a ap ears

Find g

(SVD) 4.2 .

with minor

modif cat ns

a =

L,a

1.69

=

f,ocN

direct on.

eW

that

os eW

integration)

wmas

eW

pPs,"(w

T

In

The and

data

for

rof

and

in in

the

lat ice actual [26].

par met rs

for

VeM

GeV.

(V)

K

the result yb of o m images the broad

be

roF adopt

(b), =

ew exp(-rw).

chan el factor

s i not have

structure

data,

and lat ice

PS

0.157

nesohc (spati l)

and

at V

Dirichlet

to reconst u d

In

motiva ed

in

maxiu

thes

yb

with n

1/5. the

in

structure: hig-enry

figures,

the

the

p

Dirichlet

oT

we

predict w,,,

evah

sta i cal ygren -wol

a point-sk

open

6.0, 0.154,

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large)

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other

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Fig.2(a) the

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53

chiral

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%

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QCD

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the

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E(p)/A

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31

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4

4

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the

and

0

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the

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si

at

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not

ther

thres old

ref.[31]

evitc f

[30].

situa ion

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as oci ted

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enha c m t

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spectral

case

the

b remains min u

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of

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rof

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near

a-meson

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the functio

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saw

baryon

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rest

in

-owt

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:

um

p,(w)

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as

=

Near

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),m2

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part

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sym etry

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(30)

/ 43

- ),m2

=

p),

the

thres old,

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D eR w(l; this

mas

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T

c o O(w When

2

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2

w =

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D; ( W )

ther a-T

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2

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ew

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pc -

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restored, D eR w(l; D eR w( ;

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=

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can

be

yle os

(efctiv

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vanishe

0)

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TC

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befor

to

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.,m

the

Ther fo ,

as

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0. (3) rep s nt d

yb

the

imag n ry

part

fo

the

in

41

whic that metry. a-model:

show

this To

an

enha cem nt

make

enha cem nt

the

wher

argument

t r is rof

M Althoug

m,

eW

periments a inher t smal fight enhancem nt

for

l ew

MeV

at

the

let

us

partial

,m2

the

evalu te

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eW of

in

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SU(2)

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1’ inear

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in the

confirm

c- .

with

final

Rec ntly

A

chiral

as

the

s-wave

conde sat

number yb in

Chan in

scat ering

T-T

P

Fig.3

and

.,m2

this

-+

in large

the state

47

They

fo

functio

hadron/phot n

@(p

4:

The

fo

that

it

the

nuclear

mat er

vacu m phase

par met rs

does

and

and

describ

Haym ker shift

to

(a)

is n o t a recisp the pion dynamics [3]. The coupling , f = 93 the one-l p orde .

rep oduce in

as

wol MeV,

enha cem nt

is exp rimental y

2, but in t h i s range mas distribution model cal u tion a hint about density. theoretical in t h e

beams

measur ment.

interac ions, background is p r o m i n e t , observ d increas

char te is c

col ab r tion

in

of

ther the

reaction

0.9

Measuring

is a chan e [34] repo t d

A(T+,

works

the

data

are

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some

cal u ted

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[32], the

[30].

(w)

fo

feasibl phot ns

ReDgl

the

exp rim ntal y,

heavy branchi g

mainly

to T+T*)X

yield - , + : rof ’ i h with increas g fo -=+:M s i in t h e I = J pres nt d in [34] near in F i g . 3 and 4, whic owh the partial resto a i n CHAOS

that dram tical y

although

(38)

-

is 0 . 7 with

po) =

toge h r

thres old

-T+

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l ew the

be n

a lim ted ew emphasiz a s shown det rmined

Po

CHAOS

208:

to h aveh

only QCD, 1GeV

ap roximation,

value

spectral

with

0r72 --+

up

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plausib e

To

A and as

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fo

(37)

linear

The

pairs invar nt t o our provide fin te Further enha cem nt [35,18].

with

W).

=

distribution 2 to

functio

quanti ative,

index

model

p2,

00

q p )

above

the

par metrize

the

shown

flavor

spectral cor elat d

(36)

140

=

(4

The

more

the

rep s nta ion =

In

the

ai-i?.?. =

en rgy qualit vely constants

fo

si genricaly

to prelim na y

whic

fo

the

in

spectral

is ref from 7 2 si lsoa ratio si coming from indf the signal. on the data with t h e mas near the ,m2 A . They = 0 sta e. The ,m2 thres old sug e t that this f o chiral sym etry unlabe

linear

measuring targets

nuclear

a

the

the

studies

real

smal .

are

the

inter s ing

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Nev rth l s ,

T’s.)

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A

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have

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usef l.

background

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Measuring

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72

ne ds

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T+T-

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51 10 8

0

4.0 0.2

6.0

1 0.8

0

f

6.0

4.0

2.0 L I

"

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, I ,

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g b

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t

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w GeV)

Figure real eral 05 from 6.

one

descript on fundamental

part MeV.

3. values bot om

of

Spectral In

the of

@

the to

functio invers top.

=O G / ) . (

rewol

rof

pro ag t

o and

with

panel,

the sev-

myk decras

@

rof

Figure

=

Same

4.

VeM

1

8.0

(GeV) W

with

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myk for

057 =

SUMARY s i a theory

QCD should

Among many esting quanti y. QCD etc) and relat d to the can directly In relation SPFs f o light yb dileptons. cleary in t h e as a soft and relation to the as J / * and Since ther

are

kep

in

theory

other from

compare

to vacu m nar ow

’Q

of alwys

mind I can

exp rim ntal the

vector

observal,

the

meson coletiv

are

not

most

phenomlgy. be evitc f

in the studie

scalr-io

of

chiral

(p,

wol

exp rim nt w

spectral from

sym etr

and

4)

only

of rel vant. numeros

of

mode

ti huge quarks

when

width

recnt

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in

relation

could

functio

the

action.

Namely,

"o" becaus

interaction. enrgis

the both

hadronic

data. and

strong

ta

fundamental

theory

fo deconfimt

posible

and

physic

SPF

are

ev rything

SPFs

Also,

withou

are

most

the hot/dens

decaying

devlopmnts

chiral

such

as

QCD are

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Althoug

terms

also

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much

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evitc f

(4,5 6)

observal

eith r

interm d a they

two

mat er:

SPFs on

SPFs

si

pions,

sum throug

since

into

simplet

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are

(parti l y)

in

but

directly

does

QCD

can be

theory relat but whic

interfac .

heavy in

dleif

rules,

hot/dens

"a of

action whic

si t h e

resto a i n inter s g:

sym etr

(SPF) action

SPFs

the

the

the

eqs.

of

not it aym resto d. meson sum

or

observd

yleso c

lat ice

,f H.S

the

interew

mat er, wohs

up

ap e r such rules,

In in

61

lat ice understanding co perative purpose.

QCD

and

in the

fo

works

efctiv

field

in-med u

betw n

theori s,

hadrons

theorist

i t si q u i t e t h e near

in

and

exp rimentalis

yleki

fut re.

that are,

ew

Experim ntal

may

have

course,

fo

more

inputs

es ntial

and

solid for

this

the

REF NCES

Y.

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Hol and,

Nambu,

T.

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3. 4. 5.

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contribut ons roundi g cur ent takes

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el ctromagne ic

emison

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[20]

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)1 (

this

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data

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172-42[

the

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[30]

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boundary data

[2 ]

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esntial

]13[

rates

in

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as

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a onsequc in a heavy-ion comp ne t

a simlar efcts

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mat er

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[

CER SINA45

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Pb(l58AGeV)tAu

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2.0

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Figure CERN-Sp elc tail’), tion decays

4.

CONCLUSIONS

chiral informat excita ons the chiral when

This

resto a i n

Low-mas

[25]

talk

meson

frezout

lines:

has as

Acknowledgmts

It many

si

a pleasur fruit l

(hadronic

co ktail

l ew on

discuon.

on

in

the

nuclear of

GeV ind cat g

spectral a broadeni g

as simlar

evalu ting The ap licat on ni recnt heavy-ion 0 to 2 data romf production rates phase boundary of t h e quark-h dron would lsoa cor b ate transfe in t h e transit on In t h e near fut re RHIC (adv nci g a t GSI. Thus el ctromagne ic understandi g of

8.0

exp rim nts

first

fotings

in duality

strong

to

enrgy

G.E

cal u tions

at

inter la on

interac o

thank

swoh

pertu bative that

from

furthe t o a wen

of

the

sum

restora ion

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dilepton observal

The

whic betwn l iw

E.V

in

as l e w

Shuryak

be

vacum taken

be

of acordne

yb

exp ct d

as

the encod

decras to

might degrs

yb

the

and

precison

of

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schemati

an

hadronic vicnty

PHENIX contiue

Sorge

throug

around

as of

the

exp rim nt

exp rim nt

the

rof

proges

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3.0

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to

with

consta

descript on

’

’

empir cal low-ying of

of

decay

and

fredom.

"

compared contribu ons

treatment

ap ro ch pion

I

at

con e ti

observal

of to

spectra extrac ed

in a variety

the

a easonblr in-med u ni t h e b e realizd s i located the

ap e rance A

!

5.2

as

[24]

radi t on

with

T "

2.0

1.5

phot n

lim ts

meson

struc es.

temp ratu e/d nsity

Ic/VeG[

,q

Direct up er exp rim nt

vector

leads

struc el s

partonic

featur s

the el ctromagne ic

an ih l t o

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Brown,

yb to

q

to

data

frontie )

In thes

thermal

[ 11.

line)

rule. CERN-Sp

mas .

08AW

char te iz d resonac

that signaled

chiral

thres old

are

the as

mat er.

0.1

\

" " " " ’ ’

’

0.5

6.

Figure CERN-Sp: the in-medu (ful

the

parti-

modifcatns

hot/dens functio s

model

invar t

the

mediu

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an ih l -

m

mat er Weinbrg

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+r

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at line:

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" "

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spectra

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of

towards

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It 143I

[3 ] our

in

and

at

28

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e t al. .02

G.Q

iL

Hadron

K.

’

and

02

Maruym

Nuclear

Elsevir

po

meson K.

Maruyam

the

Electromagni

Probes

sthgir

lA

92

resvd.

nucle s

Nuclear

of

vacu m

det rmined values.

op

requi s

Study,

Tan shi,

(3He)

ident f

For

a variety

Althoug . mas decays fo modif cat n.

exclnt

B.V

(Editors)

predict

has

in

Toky ,

be n

the a modif e - as

tested

coher nt

of

Japan,

modif cat n by

by

While.

Univers ty

18-02

in

a tag ed-phot n

phot r duction

using the

Toky

the

the

mas

Soding invar t

T+T-

contribu on

exp rim nt

proces

model

mas

in

spectrum

fo on

par met rizat on spectrum

ad it on

the to

the

at

nucle s.

are

observ d

the

meson

op

Toky.

consi te

in

vacu m- s

The The

op

the

incoher t

in

nuclear meson

mas

with

and

po.

INTRODUCTION

such mas e one

brief

3-21,

Theor tical y

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easi t

Scien

with

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a

for

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sci yhP

H.

in

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as

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belivs

mas

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nuclear measur ment the

decay

This

in

The candi ate

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widths that theori s

mediu . many

predict Thes

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particle

a direct

Study.

fo

fo

Synchrotron from

predict

to the the

the

predict ons

is in

by

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lightes

and

op

9 insti utions

theor tical meson

(ES)

fo

A direct construc ing

thes

of

the

Toky

yb

are yaw

topics

mas - hifted

3He. fo

to

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is t o the

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meson)

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Then, TAGX

measur nt countries:

in

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using

sev ral

models.

have

the due

reviws

the

are

bag

vector

predict on. in

ther are

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det rmination

status.

the

theori s values

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pa ers

hand. mo enta.

examine

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exp rimental

exp rimental

meson po

exp rimental shift

hadrons

the

nuclear is

sum ary

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types be n

true

tested

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(ES134)

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mas avilbe

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talks

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physic

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1-GeV Can da,

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topics. car ied Italy,

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the

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Korea,

measur ments

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in

vector

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si

mas

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of

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observations,

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the spectrum by

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examined

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beam whic

direct whic

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at

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the

[14, 5] Insti ute

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fo

the

as

the are

a very test fo

the

1.3-

03

PHYSICS

2. 2.1.

The

in Q u a n t u m is resto d decr as exp rimental y sym etry Chiral in t h e the enviro mental sym etry f o the the values Mas - hift cal u tions QCD hadron rescat ering dep n ce Al

density describ be normal 2.2.

ekil

shown

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rules

mv*

time-l k as

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etc.).

yb

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this

that a hadronic

in

it w i t h Table 1 list get a hig decay is t h e best soluti n.

the

the proba il ty

pro e ti s

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on

observ to

in phot n

observing

change

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restoration shift

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coupling

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decay

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meson

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change

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(a,)

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on shift from

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mo entum

is

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particles,

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at

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with

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mas

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conde sat partial

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enviro ment. vector

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ins de

nuclei

en rgy.

the

the

ins de

produce the the det ct exp riment

numbers

than

Experimental

Bertin

The

Decay

and

VM

procedur VM

are

p is t h e difernc those

nuclear

proba il t es

cal u ted

mediu

using

pro sed ins de

with this

of

[19]

is:

MV ins de

radi

hig er

design

Guichon

velocity.

betw n

are

at

a stable interacts decays the particles

of

to

the

nuclear

reconstruc method

the

as 3He

en rgi s.

At

a functio

the

nuclei;

and

(TAGX yb

around

the

mediu ,

nucles has

of

Pb,

a method the

using

Figure mas

-em

op

si

"p

options)

nucles

by into

the be n

with

efctiv

two

mas

"p

shape AM

measur ment meson the particles,

car ied

mas

mas

pendi g if cat on.

fo vector

spectrum,

the

A

2.

(MeV/c2)

schematic l shape

shift

or

fo

phot n,

out

up

mas .

AM.

is

in

Broadeni g

a two-peak is t h e signal

phot r duction

MV

of

whic

to

now.

the

vac um

a super osit n

fo the

vector-m s n

invar nt

T+T-

on

and structure

that

fo

mod-

mas

nuclear

(VM)

tar-

the de-

32

(1) interval (2) pairs. fractions phot production producing el ctron

eW

have

to to

examined

reduc

and

escaping

interacting

reduc

(3)

fo

the to

the

the

ac el rator.

What

The

mas spectrum

shift

mat er

al. than region MA I- 1 3.2.

this, proba il ty

takes

decays

to This

to

escaping

density,

change

the

nuclear due

the

lepton whic whic

is t h e light

from in

signal place

decay

spectrum.

final

pairs

the medium,

condit ons

the

nucle s. are

the

1 show

to

and

reality.

two

mas

the

has

min um

fraction

heavy

that

measur

nuclear

test

use

the

decays

spectra.

the

production

points.

fo

reduc

light

be

ad it on factor (TAGX

e+ -

large.

is

reaction

and

outside.

2 show is i n t e g r a t i o n

the

to

lepton Decay smal beam

the

options): fo

the

low,

(1)

and

pions

bad just

option at

over

(2)

the

When

resulting

are:

JLAB

the

not

a schematic

time

be

fo

pairs,

FSI

nuclei

ins de magnitude,

decay

They

enough

should

el ctron

)-ri.+n

Figure

spectrum

should

test. give

MV

det ct

operation

delay d.

to

fo

both

mas

lev

instead

3He(y,

in the

be n

to

the

fact

hig -duty

befor

and

fo

(FSI),

radius

This

nuclei

a sign f ca t

with

experimental

nucle s,

and

the fo

a prompt the mo entum

interac ion

av il b e

the at

decay

nucle s

In

space,

a hig instead

the

the (-lop5).

smal

a hig -cur ent, be n why

the

nucle s

from state

signals,

not

reason

has

the fo

interf MV

are

had

the

Figure

? ins de

ins de

mas mo entum

to

nuclei options

that

fo

requi s

threshold.

the

a superposit on

section

use TAGX

si

proba il ty

with

cros is

phot produced

distortion

condit ons

mas nuclear

the such

EXPERIMENT

3.

than such

is

invar nt

7rf -

3.1.

VM

enha ce

VMs phot ns,

Our strategy use VM-m+.lrt o compensate suf ering befor The decay a t lower en rgies. po meson production 2.4.

the

SE as

An

A

[20],

Photon sup lied 1 .% idea lO%-duty

TAGX magnetic

This

the

was

and above

and

beam a tag ed-phot n smal

pres nt it

pro sed

1 GeV. CEBAF.

factor

spectromet r spectromet r

was

number

pO-meson

to sucefly Figure

had

extend be n

has production.

3 show

beam

fo

not

av il b e,

realiz d

the

en rgi s

be n duty

the

up

ap ropriate in ac el rato s

whic

factor 1987.

with was

1.2

to

The in

the

GeV

rof minor tag ed-phot n the

the

coin de

with

a duty

investm n best world

in

the

befor

world

measur ment

factor

fo

by

beam the

in

operation

Yoshida with the

with a large solid angle f o r 7 sr h a s be n constructed gen ral-pur ose det ctor f o phot reaction measur ments y b using the hig er-duty beam in 1987. This TAGX spectromet r was used orf a n exp riment that realiz d design in t h e prec ding section. I t asw for t h e measur ments f o t h e 7r+7rT phot production o n t h e 3He nucle s in t h e -/E region losec t o t h e op production threshold. No measur ment of op p h o t p r o d u c t i o n on any nuclei has be n car ied out so far in t h e 7 E region. The experiment used the tag ed-phot n beam and the large- c ptance TAGX tromet r [al a t the 1.3-GeV ES. The phot ns (5x105 s’,1 in i n t e n s i t y ) with en rgi s 0.8 -1 2 GeV ( 5 MeV in t h e en rgy resoluti n) erw inc de t o n a cryogeni 3He

les et

more

en rgy

fo

as

factor

a

the

spectar-

fo

3

z .c

CEBAFJ

4 -

3 -

w

2 -

g ;

Frasc ti

,.

~. ~

1

’07

A

1

MIT-Bates

’ (

0

get measur d velocity vector pion ev nts used for wer mas 3.3.

fo

ined mas

of

ap lied

K, mas MeV/c2,

3.4.

col aboration. Regina, this

(0.35 det rmination.

ev nts

Taking

TAGX contribution.

les

fo

cap bil ty sev ral

the

was

in spectrum

Da t a

pa er,

such

for

whic

than

Da t a

in

the

(AdTR) Calibration

in

g/cm2 simultaneously

ident ficat on

observ d

used

The

det rmination

and

for

the

:Bon )

0

SPrinp-8

-

x

0

ELSA

distribution.

po

into

the

the fo

ev nts

made

experiments, meson ac ount distance gives

are

4 MeV/c2,

fo

The the

another results

MA l ~-

Mainz)

ai

The

with

and

fo

the

the

wer

trajectory

Four-m enta

result

reaction

the

TAGX.

for

spectromet r det ctor

TAGX

point

fo

ev nt-by e

(~,x+T-)

3He estimated

biase

spectromet r

and

the

measur ments

The distribution

phot produced wer an lysi

particles

by

whic

ev nts a det ctor and

ac eptances

as

charged

perfo mance

el ctron

the

fo

methods

3.

%1

The up

ac el rato s

in

time-oflgh

magnetic show

fo

data

with obtained

physic

wer

TAGX

an lyzed

was an lysi mainly

in at

made has Toky

Toky ,

at be n by

Toky

and perfo med

then Yam shita

in

cal u tion,

det ctor

know

than

decays

and

absolute

smal er

19 4

deliv r

that A

et

Kag rlis

two-charged

the

gaus i n

the al.

background

pions

fo

fo

[2]

TAGX(ES-134) col ab r to s

enha ce

et

are

pions.

po,

to

for

tif

the

op

al.

pres nt d.

they

exam[21].

Calibration

two

mas

wer

wer

TAGX

and invar nt

be n

width

to

factor

mo entum-

stage

than

by by

for

has

to

wer

fo

pions. into

world.

particles

T+X-

this

(23cm)

the

duty

factor

prio

1 GeV

the

on two

fo

in

peak eficns

duty in

than

measurem nts field

reco d

! tion obtain

to

particle

no -target

a clear

. Detec ion

l ew

10 %

with

the

its

1987

charged

show

was

ac el rato s

in

greater

the

simula!

extende

%02

en rgi s

whic

[2 ]

SE

to

is r e c o n s t r u c t e d t o be t h e invar nt mas yb loking for t h e nar ow- idth , K whic the ongerl efil f o ,K f o c ~ = 2 . 5 4 cm betw n the T+Tvert x from the beam TM distribution (Fig.5) hows a clear peak. the peak posit n t o b e 0.6145 MeV/c2 consi ten with t h e ,K a s u m p t i o n . eW obtain and AibfT,=20MeV/c whic a r e much

an lysi

ac um lation wher

as

Figure from other Those with

Tokyo

thicknes ).

mas cor e ting

~,

0

a cut 19.9f5.4 ac ur y

[23].

to

The si

the the

width.

In

in

34

Figure

A

4.

schematic l

layout

RESULTS 4.

4.1.

is

sit on

Production

Ther

production that that nucle s coher ntly quasi-fre

867 obtained threshold

AND

po

breaks the

mechanism

phot n production

av il b e MeV/c2), The

make

are

phot production in fo

invar nt

sev ral

fo

two nucle s. an

to in

fluctuates

produce

our

and both

mechanisms

fo that

elastic

the

thres old hig est

on

T+T-

the

threshold it is 870

production

mas

the

TAGX

spectromet r.

DI S C U S I O N

types

the

fo

distribution, production

po

In dif ract ve

the

into

phot n

the

meson.

the

production leavs

region.

the

forme

vector

scat ering.

While

nucleo .

MeV mechanism ,

en rgy

on

on

the whic mechanism .

mechanis

target mechanism,

the

nucle s

meson

The

the nucleos

3He bin

fre

has

are

in Al

of

nucle s

phot n

the

the

the vector

nucleo s

for

021 - 4 discu e

They

nucle s,

si

nuclear

coher nt peak

in

field. the

incoher tly. 108

MeV in

are

and

domina ce

produces

contribute

nucleo

a broad

the

on

unto ched,

MeV, (1)

this

structure,

section coher nt

production. whic

i.e

the The

the

meson

the

incoher nt model meson

nucle s

predicts

Neith r

(at

the

can

mas is j u s t [2 , 8]. (dif ractive)

coher nt

be

contribute

osla

The

one and by peak

above a superpo-

the the

data

of

result

the and

40r

35

30 c

W

)v

>

a

E

20 10

Figure the beam MeV/c2

0 30

50

400

600

M,,

Table Mas the Mas 747517

Soding

(2) to the mas ac ording the 4.2.

matical

and

2

width

(MeV/c2)

incoher nt (4) 7 5 3 ev nts and

production

M

wher and o M 151 21 is signfcatly the shift outside Pos ible skewing and the

the

mis ng

is t h e t o their

mis ng

Coher nt

6 show

region.

resona ce should

the efcts

cause Soding

nucle s.

is t h e

M

data

invar nt

fo model

invar nt

mas

ap arent [25].

wp

the

eW

fo

Breit-W gner

interf nce,

the the

This

no -mas hift mas

T+T-

table

can ot

value,

shift used

the

are the Soding

the are other

sy tem,

be

interp et d examined.

Ros -St d l ky

are

but peak

Am, categoriz d

ev nts

in

+

M,

are

r

the the

made.

Ther whic

to

into

be

comes mechanism,

are

mas from

width of

in

by mechanism

the

fo

for

kine-

formula,

obtained shift, the

resona ce,

op

know into

pion with

coher nt

the 706f9

ad it on rej cting is t h e

incoher nt.

mas

sev ral takes

50

the

by

m,

two

the

width The peak the

around

from

par met rs

consi ten

with in

ful mas

wher

mas awy

rep oduce

4

production folwing

sy tem Breit-W gner

T+T-

was

the

fre

whic

si consi ten

whic

model

fo

n+"i~-

the

f o the the p-wave

fit ing

at

peak

proces

(3)

discu on

invar nt

vert x

A

K,.

coher nt

the

by

the

No.

and

the

T+W

text). is t h e

/dof

0.98

distribution

rep oduce

with

from

A

with

(se

the

s i hig er than f o the ev nts one si orf and the

rest

values:

A

1).

with the

(Il x)

mas be

mas .

as

production,

resolution),

may

Table the

The

mas

within

si consi ten wol (cf. as ociate such

mas

mas .

production the

The

Il ia the MeV/c2

3He

in

x2

meson is exclud

op

whic

spectrum

(MeV/?)

168+24

(quasi-fre ) whose

mas

T+T-

Width

(Mx-

coher nt Figure

for

model.

80

700

(MeV/c2)

5.

ev nts

rescat ering, ac ount

MeV/c2 becaus

of

decays mas the

36

7

lo

1 a

400

600

800

M,,

Figure tion 104-2 with to solid wher and

the

the

A

6.

obtained

p-wave

invar nt

curve

the

the

in

a fit

is

solid

dot ed

Breit-W gner

rof

interf nce

for for

sured mas in

4.3. incoher nt bution. by might the

1

--

d~

fore,

Thick mas

si

the

for

A ~ ~ ~ l l is a n f o a itf

interf nce using

The

are

results

ew

the

first mas range op p r o d u c t i o n number Fig. 7.

observ d

dep n ce

Incoher nt

Figure

An

neither phase

be

time.

8 show region. filed

the space

As s i shown on the

the exc s p-wave

with

production.

phot produced for

production the other

Breit-W gner

+ 2

Table

Thick

in

production

mas mechanism

the

two

Fit ings

the

Breit-W gner in meson

7. whic measur d

mas region

the

data

sections

Pres nt on

Dashed

the curve

deuteron

for (solid

data

coher nt

A2I3 show

cir le)

[24]

(solid

dep n-

Drel

type

production.

rT +7rT -

(3)

values

Fig.

posit n

Cros

2

(GW

op

po

A2I3,

1.5

YE

ADrell

is shown 2. the

with

deuteron fo

peak

formula model,

betw n

the

invar nt

The in

is a fit

with

2) /r( 1

model

in

consi ten

curve

(TAGX)

1

7.

Figure production. and squares). denc .

range

production

+ ~

distribu-

Soding

vacu m- as

po

this the

the

the interf nce.

~

listed

mas

distribution.

(W2 -

en rgy

dashed

the

wT

T

mas

phot n

with

betw n

- do -

result par metrization

invar nt

the

’He y’He->po

0.5

(MeV/c2)

T+T-

MeV.

0

1000

-yd >pO

’

cros

600-700

in

such

the

po

the

width formula

as

fo MeV/c2

meson

3He

section, is slighty by enzB f o the data

the

includ g

and the I t rep oduces

6.

fo

sets

distribution and mas

Fig.

are

the

the

T+T-

one

or

production

in

nucle s large et

value al.

are

than consi ten

type vacu m, integrated

sy tem

si not rep oduce the Soding two

fo

thes

the

pres nt

at

background.

the

over

total

When

one

each

from

the through

data i.e

around

[24].

T+T-

dif er nt

nor

Drel

model. mechanism

det rmined

coher nt reason bly Ar7

the

.0-a cros

other

Ther -

threshold the as ume

mea-

section as

chan el

a

se n

in distr The

The

with

difernc do

the l ew not

or

31

improve region. Yam z ki-A a shi target region density, the 0

large fre are the er o also modif cation

the

rep oducib l ty.

Another

This

mechanism nucleo

Saito-Tsu hima-Thomas quark-meson meson

A tif

50-6

modif e ,

MeV/c2 is n o t

that mas

enough

reduction

the

are

to

the

They

cor elation the

might

case

ap ears

coupling explain

model

they

estimate

in

[27]

no deform

with

when

this

experiment.

predicts

under

get

the

the sur ounding

the

237-5

the pres nt fo the fre po t o be det rmined by 9 and listed in in Fig. X2/dof from 8.9 t o 2.0 subject t o change when ( 2 ) the col is na broadeni g si t a k e n into ac ount.

with

par met r

shown fit ing

[26].

and

whic

is becaus

sum

wol

mas

mas

the

Table

fit ing,

enha ce invar nt

fo

mat er mas po

reduction

mean MeV/c2

enha cem nt.

shape 3.

The

the

(4)

and Breit-W gner

-Seding

33 00

Coherent Incoher nt

are

(3)

Breit-W gner

-

not

mas , whose

the

0.15&

nucle s Ac ording magnitude

The

sati f ed.

dep n ce

formula

the

The value

)1(

does

to

reduc s

op

The

not

mas

normal

whic

is t r i e d .

mas - hifted

fo

the by

30

N

width fo

work.

using

the

Y

is a

results and

its mas

1

E K

10

0

60

400

80

M,

Figure tained the above cut. not

coher nt work

A

850

8.

the fit ing

Invari nt

for

MeV/c2

incoher nt

is

with

400

(open). the

60

500

distributions

region due data.

to

Soding

The

drop

the

model

(solid)

and

hig er

ac eptance

ob-

Figure with shifted space ducing

does

a sum contribution

Incoher nt

9.

shape the

fo

(first

700

800

900

(MeV/c2) M,,

mas

incoher nt

region

300

(MeV/c2)

the

po

is

pres nt

peak),

data.

proces .

mas

A

shape, and

sucefl

the

fit ing

a mas -

in

rep o-

phase

CONCLUSIONS

5.

tested serv d

in

10

Theor tical y

by

have

a tag ed-phot n the

predict

mas vac um

mas

exp riment

modif cat n and

the

vacu m

at

Toky .

fo

the po

width.

Coher ntly

meson

in and

thes

the produce

3He facts

nucle s confirm

po

meson

has

be n no

by

the not

is

0

5

FP

20

mo entum

3He

meson formula

in

than

the

po

=

10

is pro sed en rgy

potential A substructure hig er in

fo is

MeV/c2

spectrum

ap roximation. the

as

inclus o

.

-Seding

mas

is much

field

40 o

aver g

60-7

the

a mas - hifted.

value is large,

the

nucleo s.

density

condit ons

and

the

ef cts

Obtained

as umed

mechanis

mas

ob-

is

83

Table The thre are

3 7r+ iT-

fixed

invar nt

contributions:

in

the

Mas

(1)

modif cation have reduction

the

in

mas

fit ing. (Mef/c2)

65 k8

(2)

by

mas

spectrum

po,

in

mas - hifted

(2)

the

incoher t

Width

coher nt

production

that

%.

proces

phase

is r e p r o d u c e d Numbers

space.

with

82&14

Incoher ntly as umption

an

that

by

without

Relative

mechanism.

s i consi ten

and

po,

(MeV/c2)

15 15

768 the spectrum

15

(1)

a sum

fo

er o s

fraction po

18& 4

produced

meson

7riTf-

the

meson

op

mas

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A542

(19 2) 247

84

(19 )

Norenb g,

(19 3)

Jap nes ), (1974)

Phys.

C48

Sci.

(in

6

(19 3)

J. Qju.

(19 7)

927.

Rev. (196 )

Wil ams. Rep.

and

Col aboration),

D. Thesi

Nucl.

148 .

Rev.

A617

(198 )

Norenb g.

Rev.

Phys.

Lkvai,

W. Phys.

A560 A.G.

Phys.

Let .

and

Nucl.

W. Soyeur.

Phys.

689.

Theor.

Rev.

Schu k, Weis,

KO,

Phys.

Phys. Phys. Y.

Phys.

Proce dings.

KO,

(198 )

Prog.

C51 Le,

C57

P.A M.

et al. Ph. et Nucl.

Friman,

Kunih ro.

P.

W.

C.M

Proce dings. Rev.

A48

Suz ki,

Nucl.

Rev. S.H T.

thes

(19 7). et

and al., Rho,

J . Piekar w cz, and and

Rho,

B.L

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Jean,

M.

Z . Aouis at.

Klimt.

Phys.

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RESULTS

3.

AND

The invar nt fer nt targets, $I - + K + K To evaluate have as umed t h e two tracks shape. The

Figure tra. gets. responding lead eas ev nt-mix g

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In

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46

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Table Comparison

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Hadron K.

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02

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Nuclear and

Elsevir

Lepton

devil

The Da r m s t a d t ,

l ew

as region

AMznv/Mznv INTRODUCTION hot ion

earthbound sta e

si r e s t o r e d . Various

<

,Q

q

of

and (for

Ac eptan

the

l iw

util z ng

be

transit on

pion, used

5 M

the

49

beams

recnt

ap ro ches the quark conde sat t o a t least a phenom can alre dy ,rev woH the the particle verifcaton heavy oni physic. The ightl invest ga on , decay a t least ticular inter st, alre dy in oldc

two

Under

in

produce

partial

of

becom spectral

thes

with n

short

as nuclei

they

and

(a),

a large

has

increasgly

es

The chiral

a uniqe

devil with n

may

a odifcatnm when

of

increasg

vector

be

the

widths

neutral signal

theory

the

goal

that

and

si

of

sym etry

hadron

rof

of

the

the

therfo

mediu

p, w ,

hot si

of

and produce

its

dens narow

produce

and the

fundamental one and q5

in

explor

up

rof

resonac

Electron

an

and

invar t

mediu of

and

such

yfirev

sta es

sym etri

in mas

and ultra el tiv s c

the

wol resolu-

emb d

of

exp rim ntal y

spec-

meson

ac ept n

theor tical

GSI,

Short

baryon

pair vector

particles

si t o

fundame t l

to

at

up

a large

exp rim ntal

relativ s c

set

pro e ti s.

mat er

in

in

nature,

and the quark conde sat has a on-zer vacu m value. (QCD) redictp a reduction fo and particle densit finaly leading neO exp ct d onsequc of this (mas e , decay widths. etc.) whic in groundsta e uclearn mat er. eadsl t o ad it onal modifcatns in QCD efcts. Experim ntal f o the main guidelns ni nowadys

emb d

reaction

studie

fo

hadron mase

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interac ing

presntly of

si broken

transit on,

.12 -4[

pro e ti s

hadrons

of

normal

ratio,

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reactions.

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of

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strong

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at racted avilbty

to

this

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nev

The

HADES modifcatns

to

yaw

range

sym etr ,

abundantly

the

heavy

spectromet r

.)13-l[

of hadrons

mediu

pro e ti s

of

fo

functio s

resonac

Munche,

Spectrom of

nuclear

the

long

condit s the

signfcat

in

The

with

modifcatns

since

%1

in

restora ion modifcatn

pro ag tion

partly

measur

study

prot n

deca s

normal par met r

si t h e

and

to form act s

whic

orde

GSI

at

Univers ta

DiElectron

mat er reviws alows

labor t ies.

the

HADES

Technis

sy tema ic be

1 GeV/c2.

past dens

mat er,

>,

resvd.

E12,

12

.1

rights

lA

col ab r ti n

40%.

2:

Over

l iw

Probes

HADES Germany

for

hadrons

Electromagni (Editors)

with

the

High

flPazr

eforts

B.V

Departmen Garching,

densit trosc py as mas tion

heavy

with Okuno

spectro y for

D-8475

in

Scien

pair

J . Fries", "Physik

Physic H.

decay T-

in

are

induce

relativ s c volume.

particular y width

[13,4]

The reactions

nuclear w

at ractive might

for colisn

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physic

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far

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changes of

to

hcum

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quark

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ions

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in

motiva n of

simulated

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.)

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SPECTROSCOPY ion

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sum arize

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be

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temperatures nuclear

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mas

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LEPTON

In formed, times transit on transit on. ficat ons, and volume signfcat value produce al background Electron from To disentagl alow sion , hadrons em ntary this a s aris ng yb t h e The pions various

myons

lepton

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[15].

functio s

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reaction

yb vacum

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al importance DLS rangi

are

yaw also

spectra

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[28].

and devlo ni

to

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-le

[16]

obtained from regim.

3

a

come

of

si

to

with

of

51

The pion, as sub eq nt background the measur nt meson the

avilbe compared

heavy

pair

(r

to

8MeV/c2) =

THE Gen ral

The ratio example,

design ion

for

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0

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spectrome r polar with

0.5 thes resoluti n in

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m

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proces

properties

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diel ctron only

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production

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out decay.

frequ ntly

/

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5.

CON LUSIONS

of

util z ng

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the coinde

area

Dalitz neutron

is a igh mas two out of six sector have be n perfo m d. prot ypes bcfore eficnt and redundant 20 1, with first physic Thc hysicp prog am tiv stic hcavy ion olisn,c aimed a t studying pro e ti s of vector shape of t h c invar t fact,ors of n e u t r a l meson. ties of hot and compresd fo chiral sym etry mase may b e obtained. colisn and light measur nt . When mted invest ga ion induce react,ions. and secondary beams Fut re combinat s misng mas measurem nts - guar nt,ec substantial

ACKNOWLEDGEM NTS as

chan els.

The

col abor tion

the

loca

BM F,

rate,

resoluti n dcmonstra c

the

broad

heavy

The

finaly the

fo with

avilbe

ion

cxperim nts

phot n

sy tem meson

w

an

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of

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l iw

up yfirev

are

spectromet r

more

acknowledgs DL R

The in

study

in

as

l ew

at ention to

and

bet er informat

of resolutin

pions

describ

in HADES

enha c m ts

1.

3.

4.

5.

6.

7.

8. 9. 10.

C.M W.

R.

Rap

Cas ing

V.

KO,

G.E Brown T . Hatsuda M . Her man , C.M. Shakin J . Engels, K . Saito, F. Kling

and

and and

Koch

J . Wamb ch,

and and

F. Karsch k. Tsu hima and W.

B.

and

E.L S.H

M.

Rho,

Weis,

Friman W.-D.

G.Q

Bratkovs y ,

Li, Phys.

Le, and

and

Sun,

and Nucl.

K.

for and/or

TAPS

An u.

hep- /9 0 2

Rev.

Phys.

A.W

Redlich,

Phys.

.W

Phys.

Rev.

Phys.

Rev.

Norenb g, Thomas,

Let . C 64 Rev. Nucl. 60 A

Nucl. Rep.

6 (192)

C49

Nucl.

Phys. (19 6)

Part.

803

and

the

(19)

Nucl.

R34 (19 4)

Phys.

B435 329

65

(197)

74

065A

1 85

50

A609

(195) (196)

(193) 295

41 39

be

paid

the

found

ions

ful

INTAS,

and

pion

ezis

in

restora ion in

range

and

up

to

- rof

TMR NATO,

first

decay

of det c or

ha,dron

on

the heavy uranium.

de i-

ion for

time

as

p

DLS

prima y

a long

program),

The form

pro c of

in

rela-

the

orign av il b e,

the

complet d

transit on

focus

runs

det c or

exp rim nts to

broadeni g.

dynamic l partial

the

beconis the

particular

be emison

l iw

(HTM,

270 Phys.

in

a neutron dira

EC

INF ,

ful

<

with

Pres ntly,

l iw

l iw

heavy

and/or

yb

Sci. (19)

with and

whic

about

schem. comisng

pair

both, exploit

IN2P3,

first

reactions

REFERENCES 2.

plan ed

spectroy

resonac

measur nt

sup ort

pair s,a

lepton

el ctromagne ic

utilzng

l iw

trig e

and

of

el mcntary

yield

GSI,

inst u ions.

lev

cxp riment

shift

the

the

(WTZ),

multi

spectromet r

20.

calorimet exclusiv

el ctron

setup the

foresn

plan ed

includg

output.

prog am

invart

are

GSI, wol a

of

aces si t o a n enviromt

and

decay

at

mas

evig

aim

to design

this

Particular

to

mat er,

wohs

complet d

the

l iw

to exp rim ntal

are

alredy includes

producti n

hadrons.

resp ct

selctiv

for

with feasiblty

long-rae

DF G , al colabrting

in

the ident f ca ion.

of

hadronic

ap ar tus

and

and

dielct,ron

scientf grateful y

obtained

begin

The

seri

a fast

spectromet r

with spectrum

exp ct d

DAAD,

sup ort,

is

mas

is

The

lepton

structure meson

ac ept n

and

the of

runs

lat er

the

OUTLO K

hig Result

The

with

LAND.

AND

HADES 1 % invar t

ASCR,

det c or

decay measur nt

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NUCLEON

RESONA CES RELATED

TOPICS

IN

NUCLEI

AND

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dna

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sci yhP H.

lA

Yoshida

* , T. Sudab and

fo

bDepartment

sthgir

T.

, 5

nuclei

K.

Kinash

t

Itoh,

fo

In

(7,

the

orde

reactions MeV.

Q)

10 width on

quantum nuclei

modif cations.

to in

fo

Physic ,

A the

broad

nucle s molecu ar

can

s1(53)

C,

A1

Toky

Japan

Univers ty

has

resona c be

resona c dynamics

basic l y

are

be n

structure

clear y 90

and

(QMD)

understo d

30

the due MeV,

as

Technolgy,

have

90-856, nuclear

measur d

to for respctivly.

the

quasi-fre

the

for the

be n

Japan mediu ,

to al

phot n

excita on first

time.

perfo m d.

Model

cros

en rgi s and The

decay cal u tions

The

reaction

sections

betw n

of

ap arent Q

with

the

phot produc-

the

fo 680 1 3,

en rgy

based

reason ble

INTRODUCTION

The property of nucleo resona c i n nuclear is ue in t h e nuclear physic . Rec nt measur ments section have shown clear evid nc f o nuclear mediu The DI3(1520) and FI5(1680) resona c are not section o n nuclei, hilew the A resona c si cleary whic cor espond u p t o 05 MeV f o inc de t phot n A-hole model. For hig er en rgy region romf 06 interp eta ion based on t h e olisnc broadeni g fo ne ds very large broadeni g, whic are hardly justif ed e t al. [3] pro sed that disap e rance section. Hirat by t h e co perative ef ct f o the colisn broadeni g *Cor espondi g +Pres nt IPres nt §Pres nt

and Japan

in

observ d

,

Maruy ma

Jap n

Agricult re

18-02,

be n

T.

Shim zu

Jap n

fo

have

Matsui ,

982-06,

Yam g ta

resona c

H.

980-57,

Universty, Cu

H.

Okunod, Sendai

Toky

and

Okuda ,

Sendai

Yam gat the

H.

Universty,

Tan shi,

on

T.

, aw k yiM

Universty,

Physic , 184-5,

Kinosh ta ,

T.

Toh ku

study the

T.

Toh ku

Midor -ch ,

eDepartment

~

Scien ,

Ap lied

dKE -Tan shi,

61

.devr s

Physic ,

fo

Toky

Yorita

Nuclear fo

De p a r t m e n t Koganei,

seborP

in

T.

Laboratory

1.

B.V

citengamortcelE

)srotidE(

resona ce

H . Yam z ki J . Kas gi , H. Y.

the and resona c and on tion mediu

htiw Okuno

ad res ad res ad res

author Coleg

Res arch RIKEN,

e-mail fo

Wako

Cent r

,pj.ca.ukoh t.snl@ikaz may Biores u c

for 351-0 98,

Nuclear Sciens,

Study, Japan

Nihon

Osak

mediu

fo observ d se n.

resona c . fo

Univers ty,

+81

to al on

in

The

the

Tel Univers ty,

efcts

en rgy MeV

is

the

to fo

behavior can 10

in

A 2

fo the

nucleo

the

phot absorpti n

nucleo be

MeV,

Ibar ki

of

described Howevr, of

34 , 25 -8 10,

important

cros

resona c

567-0 4 ,

l ew

Fax

this

N*

at empt

pion +81

Japan

was

yb

2 Japan

743

[1,2]. the

N cros is caused distortion

+-

the

cros

A resona c

the pro sed

resona c

N*,

and

most

phot absorpti n

terms

743

Fujisaw ,

one

3401.

an

62

A1

and cal u tion colisn absorption the T-N a t the with a large property, f o inc de t

Figure targets wer decaying

interf nce

can

broadeni g resona ce

chan el the

are

branching

branching one

remov d

and

Schematic phot ns

in

the

produced

two-pi n fo

are resona ce,

desirable.

ratio excit

ratio

about

en rgy.

the

from

80

in

to

drawing by

the

overlap ing

can

phot n

Cu.

.1

hig ly properties

and

Sl (153 )

and

reproduce

MeV

nuclei, fo

only

phot production

exp rimental

whic

Thus

decay

fo the q meson . swe p magnet t h e 7 meson the

strongly

N

the

in

the becaus

with

45

7-N

In

ew

%. have

experimental The whic

width.

couples

Ther

around resona c

fo

the this

was

det cted

with en rgy by

placed

using

and IKq

nucleo

region.

setup. particles

the

to al

by

Tag ed

at

the

and

resona c

51F

A resona c no

the D13

howevr,

and

D13

in of

measur ments

si

measur d

charged wer

the

tail

Thus.

reactions,

T)

the

5

S11

(7,

proces

disap e rance

1 m

decays

resona ce

(7,~)

nuclear other it is h a r d

strongly.

reactions (7,~)

two

upstream

pure

than

mainly to

eW

whic

Becaus

CsI

beam fo

with

the calorimet rs.

using to

det rmine have

the below

cros

phot n

ac ompanied

medium.

by

51F

Nq

fo

this

sections

the target.

bombarde

Their

modest

the

total

decay chan el

has

to

aimed such

uniq e

1.0

on

phot ns

GeV

C,

Two

63

EXP RIMENT

2.

fo

The chrotron is shown

exp riment

fo in

9 x 105/sec and its Cu targets an lysi

day. and mas calorimet rs fo the calorimet rs. length in t h i c k n e s . en rgi s deposited the 7 crystals f o t h e pure CsI phot n emis on about 6 % at f o the calorimet rs. the polar angles two CsI calorimet rs. [4]. simulation integrating the

of

086 for

typical of

and

with

was

perfo med The

.1

produce two

decaying

direct on

7 mas

beam

about

07

phot ns.

was

as

the

the inc de t

3 % about

MeV.

Phot ns

in section

consi t

The

saw

ident f

det cted

veto.

pure

with

was

fo

1 GeV

fo

the

phot ns by

CsI

fo

the

en rgy

and sev ral

GEANT3 nuclei

on

GeV

el ctron with measur d

was

The

angul r

the

exp rimental

the

whic

reaction

1.3

bombarde

the

resoluti n

with

from

the beam

fo

phot n.

(7,~)

by

crystal

de uc d

and

mas

the

phot n

averg

the

the sy tem

de uc d

q phot r duciton

in ycnei f

particle 92

of

fo

section.

wer phot n weightd

invar nt

section laboratory

the

eficny

wer

posit n

line drawing

a tag ed tag in Tag ed

fo

en rgy

is consite

cros

%.

charged

phot ns 5".

beam

The

80

whic

inc de t

72

schemati

N

The

for

the

The sup lied

rof fo

region, whic Diferntial 0" t o "09 Detec ion to al rosc cros

The

line

7 meson .

calorimet r en rgy 7 crystal .

the

using

INS).

5 10

was

was

from dif er nt al

27

scint l a ors

Each The

in rega d

scint l a or

5 ,E

value

plastic

(forme

the

tradit onal two wer from

its

with

placed the

cent r en rgy

wer

once

the

sets

angul r

inte si y

resoluti n

fo

invar nt f o pure 13.5

sum posit n

two

was

resoluti n

Monte

angles de uc d

a

C,

in

A1 front

fo

CSI the

fo

phot ns resoluti n

measur d

openi g

radiation

syn-

setup

fo

the is for Carlo

fo by

STLU ER

3.

inc de t cros that the inc de t

was

KE -Tan shi Figure.

In

Figure.

first phot n

almost

section

2,

phot n time. phot n

whole en rgy;

the enrgy. the

fo The

en rgy.

to al

q phot r duction

Open

reaction

)7.7( structure

reaction

this

The width f o t h e resona c I n orde t o clarify the on t h e semi-cla dev lop t o describe code t o describe the a phot n and becom s Sl (153 ) resona ce for t h e resona ce en rgy, branchi g ratio f o the H(y, 7) cros section 212 MeV orf the width by using rec nt measur ment result fo the two par met rizations A solid line cor espond

The value

model, phot n

the an

in

N-7

refnc

the cros

cros is uchm structure fo the Quantum hig en rgy induce

cause

wer

fo

cir les,

used 150

SI1

MeV

chan el. the

at

to

of the

in

Sl1( 53 ) section section

closed

on

hig er phenom a,

is a b o u t

than

Molecuar

resona c .

the for

with

QMD Thes

section Cu, C, exp cted

30

the values

cal u tions. width

pole, plot ed

r

=

MeV,

21

the

section and

154 Figure

in whic

the

fo

is

whic

in

Cu

at wer

in

respctivly.

tA

set

are

squares

have Dynamics(QMD)

Two

cros

and and maxi um

reactions

other

q)

A1

the

ew

ion

The H(y, are

cros

and

phot excita on

on show

heavy

the one

A1

7 production.

.19-7[

resona c

C,

cirles

nuclei have value

the

the

det rmined wer

resona c

resona c

One VeM

at

a dot ed

eW

first

simple

is also

perfo m d

.]6[

shown

obtained 3 with

have

step, par met r for

Maintz line

cor espond

as

a function fo t o the total I t should b e noticed has be n shown orf sim lar dep n ce on a t around 90 MeV quasi fre picture. wider than expected. the cal u tion based . QMD was orig nal y modife t h e QMD one nucleo absor par met r f o the s e t is 1540 MeV pole and 0.5 for t h e so as t o rep oduce the the resona c en rgy, yb B. Krusche e t al. and Bon [lo]. The the exp rimental dat . with r = 150.

10 3

64

n

e Y

W

b

oc 0

1A

cu

10

60

BO

70

90

Fermi the

p-7i

the

The

width

and

results motion, 7 absorption consider ;

C with

Cu,

qn

resp ctiv ly.

but

cros

As

the

the

resona ce

can

section.

cros be

AND

The

pres nt col is n

include

as

the

measurem nts the broadeni g.

width se n can

SUM ARY

4.

Fermi

quasi-fre

the

fo

resona c

MeV.

QMD

Pauli

cros

section lat er

the

sections

for

150 of

the

cros

the

MeV.

212 measured en rgy,

cros

line)

fo

+-

also

understo d They N- *

Total

2. (solid

(y,q)

Open

section

The

colisn in

on

rep oduce

fo

Figure

051

was

reactions

width

cir les,

cal u tion

blocking section

10

(MeV)

YE

C for C , A1

1 T

I

20

0

Figure lations

1

and

closed

the

de uc d given

are

C target

by

broadeni g the about

2,

the

Solid

on

21

plot ed 7 absorption in

MeV.

fo

C,

MeV, cirles

A1 and

in from

the

ref.

[l ] lines

forme

02

exp rimental

Figure.

pb

in

Sl (153 )

fo

s i used. are par met rization

detail d

and

and

squares

In

2.

bal nce A

dot ed

results 80

result

with

the show

a nucle s

the above

Cu

cal u tion

have in on

MeV wel

on

the

QMD

(dot ed

the

cal u tions, be n

a nucle s line

C,

results

is t h e

under stimates f o inc de t al t a r g e t s .

have and

on on

the

consider ;

an lysi A1

cal u-

line)

of result

be n

Cu

with phot n

the on the

OUTL OK

motion,

reaction I t was

show

that the

found

with Pauli

the that

the

7 phot produciton

blocking,

reason ble

the

resona c

the

on

nuclear

7 absorption

par met r

nuclei medium

can with

in

nuclei

modif cations.

r

be =

basic l y 21

and

MeV

the

65

4 L=

;

02

.B ehcsurK 0

.la

te

M.Wilhem

15 10 5

140

ramet rs

line

Total for

pres nt

data

cros

the

f 02 with

are

width

exp rim ntal on

et

the MeV.

the

higly

150

section

resona c

the

Armst ong

based

154 =

rR

proces

3.

rep oduc Recntly

150 1450

Figure dot ed can

+ 1

0

quasi-fre

desirabl

sA

al.

p(e, p)q

fo

160

H(y,

data

[12]

shown

Two

21

par met iz ons

and

.l ew

repo ted

exp rim nt in

picture. reduc

to

7). of

165Q

precis

Figure.

2,

eroM

the

150

170

.Iswe

MeV,

at

uncertain y

are respctivly.

measur nt

TJNAF;

this precis

IV

,b

par met iz on

measur nt of

shown

0.5 , =

the

fo

with

S11

of resonac

can ot

a solid,

resonac

MR

=

the

par met rs

el m ntary

rep oduc

1532

and

of

s1.

REF NC S .1 2.

3. 4.

5. 6. 7. 8.

N.

M.

M. CERN

Geant

M. K. B. .loV

M.

Bianch Anghiolf

et al., Hirat Robig-Land u

Ni ta Krusche Wilhe m,

e t al.,

Prog am Detec or

et 43

(19 5)

al., et

e t al.,

al., Ph.D. 43

Phys.

Phys. Libra y Descripton

Phys.

Let .

Phys.

e t al., Phys.

Thesi ,

Rev.

Rev.

9 2B Rev.

Let .

gnoL Phys. Rev.

Writeup

and

C52 Bon ,

(193)

C47

Let . Let .74

80(19 )5 68 Simulat on

;912 (193) W5013:

(195)

B37 BN-IR934;

(195)

026

ibzd.,

2 9R

(196)

!lo T

903B

54 637

B.H

(193)

5

193.

Scho,

Prog.

Part.

Nucl.

pa-

Phys.

6

9.

10. .1 12.

. S Hom a B.

M. C.S

Krushe Efenbrg

e t al.,

e t al., Armst ong

J . Phys.

Phys. e t al., e t al.,

Nucl.

Let . Phys.

SOC. Phys.

B397

Rev.

Jpn.

A613

(197) D60

57 (19)

(198) (197)

82

17 40 25

35

nordaH K. 20

and Maruym

Nuclear

Elsevir

De l t a

in

Junsei

forwa d peak reactions with ciden peak

Scien

htiw Okuno

(Editors)

B.V

nuclei The

Oho,

As

The

Electromagni lA

Probes

sthgir

resvd.

61

yb

excit d High

Tsuk ba, in

out

but

Charged

the

other

the

shift

data

the

data

particles at

Energy nuclei

at

goin

in

hadronic

proces

Acelrato

Ibar ki,

are

excit d

Nation l

yb

neutron spectrum 4 GeV/c.

in

inclusve

set

stil

emit ed

neutron

particles,

Japan

in

reactions

)n

On

in other

the

rof

region

at hand,

with

T+,

on

this

er w

with

GeV/c

measurd in

swoh +ri.p

peak

shift

theor ical

si pres nt d. Energy

field.

1.5

the a

reaction

hgiH in

central

coinde

constraints

spectra.

quality

the

(KEK)

Organiz t o

induce

in

(p,

espcialy

stringe t

prot n

Labor t y

higest

Resarch

108 -5 3

in

toward

higer

models

no

nuetro

exp rim nt

with

A excita on

the

the

The

(KE ) Physic

a coinde

shift, mo entu .

introduce

as

spectra

in

01

about region.

the in

to

of

The

(p, Ao) coinde

The

interp t

saw

years

coin-

a A

the

INTRODUCTION

.1

It of

Physic

H.

Chiba

IPNS, 1-1 car ied ago,

dna

particles

si

one

fo

the

are

the first excit d excita on of spectra f o outg in (3He,t) in t h e shift si caused first videnc peak hifts dep n s at ributed to thoug i t s magnut de [3,4]. nI those inc de t mo enta mo entum distr bu ion in t h e target and width of the decay products distr bution. I n orde to exp rim nt to GeV/c. The

most modife

sta e

nuclear

particles

days,

invest ga reaction

A

a nucleo

si

of

modifcatn car ied

3 and fre

in

coinde

of

A,

chan el

repo ted

of enrgy

very

smal ,

1980s,

the

[5].

saw

excita on

resonac [2]

of

had coinde

the

It

chosen

with

In

mas

in mas

nuclear an

a shift [l].

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ben

a forwad sem in ielcun and oincde becaus

in

sen

exp riment,

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si

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the

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posit n

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ew

to

role

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also

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whet r

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peak

p.ir-evnts the

physic

with

importan of

mas nuclear

hci w

this means

in compare

plays the

prot ns

while

a uzle.p A production both nclusive

modife

in

mat er and

out

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of space

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(or are

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of

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EXPERIMENT

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Experiments (PS) a t the Energy Ac el rato FANCY for posed fo a and a cylindr cal sen wires, resoluti n MeV/c wer cover d a of a hod sc pe forward neutron are 3 cm as embl d tector was particles. cover d polar wer an lyzed.

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Physic

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RESULT

Al in t h e a r+(n-event), others. exc l nt must about 6 ev nt agre d Fig. tions det ctor (p,n) neutron fractions 0 2 %, whic Fig. gets.

ev nts

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and

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Figure

6

GeV/c mo entum. production

=

0

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-

the wol mo entum spectra wer binding en rgy culation was expr s ed was achiev d a t 4 GeV/c. and the Fermi In order on the model consi tent agre with in t h e binding triv al kinematic cros sections a t 4 GeV/c based on understo d the invar nt

Doubly 6 degr s. 4 degr s

dif er nc al with

Calculation is shown

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wel

man er. each

an

a gaus i n with This moti n t o overc m introduced en rgy op C-nA+ /op -nA+

[5]

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dashed

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Solid

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the

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-35

shown as

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fo indep ntly.

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While

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fo

fo

120MeV

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fraction

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1.5 GeV/c dif er nc

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fo

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52

whic the

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line) The

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reactions

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spectrum

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treated

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be the

section

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spectra

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MeV)

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The (p,p Ao)

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C

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ev nt

H target. ac ount in uclei.n model used [5]. The width ( o ~ ) fo the Fermi The best match t o the experimental hilew i t asw 25 eVM for ( p , p Ao) fles inco si ten becaus the bind g compared

Figure

f 0.1

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sections

to

mas

picture

broadeni g in t h e f o nucleo s in Ref.

Gugelot

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40

fo

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Above

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5

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A. The the target. Fit ing 190k25MeV. neutrons romf with the exp rimental to understand shown by t h e nucles for p - e v e n t s , final sta e interac ions distr bution. Fig. 4 show with result of

targets. to Using quasifre

More

distribution,

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10

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Figure 3. (a) Momentu spectra gets. inesL show our model cal u tion those in ref space (M=123 VeM (OF) are 0 4 = Q MeV, 021=Frc moti n H target), and ,O=Q F=120 MeV/c H targets. pn+ invar t mas rof C a n d r=1 5 VeM (solid), M=1207 VeM

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MeV).

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make

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130

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120 Invarit

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1207

from

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fre

of

space

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as

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,,M VeM

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ing

r

190

=

VeM

si produce ni a quasifre the A si esl than 04 VeM and nlyo a pion comes rof such vents dep n s rof stnev -T ifersd signfcatly distr bu ions of pions data obtained os reason bl , althoug a final conlusi: The a s had ben alre dy ens on i t s mas ; proba il ty smal er, elihw proba il ty Proba il ty of absorption section of N A NN shouldn’t

from target nucles proba il ty spectrum Angular ure. al exp rimental t o be most t o akem fre space strongly mas si large . the cros

ni

mas

are far

more

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out

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frame,

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mas

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proces,

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and yb

pion proces

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cal u tion

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mas .

as model. smaler

[lo].

proces

the

a prot n si c a p t u r e d ionp proces ).

prot n

si ylevitc f

section indep t

the

the

theor ical

cros

(coher nt

fo

Fate

decaymo entu

shown scenario

when

the

A

mas

that

dep n s when

its

-gif sem

necsary

than a A

the

The

the

si

of increas

in

Considerg

yb

becaus

in its

mas

si

80.0

2

h

0

60.0

z2

au

3

if 0-

N

0-

40.0

E v

20.0

B

0

08 10

120

Momentu Neutron

Figure woN

proces?

proces.

qualit ve y Ther

A’s

yhw

pion

yb proces

exp riments

In

are

produce

two

ad it on saw

car ied

of

in

understand to

hadronic with

big

forwad

neutrons the

question thes

out

question , hig

at

LAMPF

(MeV/c)

proces

behaviour

left;

enrgy

resoluti n.

we

rof

(1)

ref id

from

should but

[l ]

of

what

-p2

T-,

A

s i the

carefuly An

stil

in those exp rim nt

clear

and

pT-evnts

nuclei orign

produce the

fo

produce

C target. on

examin

answer

in to

saw

reval

in

A mas the

el ctromagne ic

not

coher nt yet

the

hadronic

shift?

obtained.

and pion cohernt

SUM ARY

4.

reactions types det rmined

spectra

ew

(2)

proces

Momentu

4.

140

In

sum ary, ac ording

at

1.5

as

we to

GeV/c

a functio

have

car ied particles

on of

H

emit ed

and neutron

out

first C

in

targets. mo entu .

coinde the

target

lA region

and

(p,n) Two

inclusve and

evnts types,

measur nt fractions pT-evntad

er w of

clasifed each

of type

,tnev -T

into

n)

(p, er w

6

73

showed

wer sign f ca tly strongly proces

large

l ew

changes

understo d on

its

are

I would Nak i, Sak mot , H. Kitay ma, bartzki. like

K. H.

from

mas .

qualit vely

T.

A.

iV.

Kobay shi,

by

that

to

fractions.

fo

in

For

a quasifre fre

Proba il t es

A

picture,

decays.

of

understo d.

thank

al

Man be, Kato,

pn-ev ts,

K.

T.

col ab r to s

T.

Nag e,

Aoki,

Baker,

H.

C.

quasifre

Glash u er,

Nunokaw ,

The

but

fate

fo Tokush ,

K.

mone tum

the (decay),

the

ri.p fo

invar nt a A

KE M.

R.

Tan ka, Ransome,

H.

spectra coher nt

SP

Sano,

REF NCES .1

4.

2. 3.

5. 6.

8. 9.

7.

10. .1

D. V.G B.E C.W T. R.G K. P.C J. A.S R.

Contardo Bon er Nag e Ichimaru Chiba Gilman

Bjork

Gugelot,

et

et

Jep es n,

Car ol

et et et

Able v

al.,

al., et

et et

al., et

Phys. al.,

al.,

al., al., al.,

al.,

Phys. Ph.D.

Phys. Nucl.

Phys. JETP Phys.

Phys. Nucl. Phys.

Let .

Let . thesi , Rev.

Let . Let . Rev.

Instr.

Rev. Phys.

Rev.

168B(1986) 40(1984)

C

19 B(1987)

Let .

C 18(1978) 63B(1976) Univ.

fo

Meth.

30(1984)

C

A57 (19 4)

67(19 ) 14(1976)

31. 763.

Col rad , A237(1985) 654.

31.

148. 31.

635.

1986 1982. 2 7c.

59.

in

(unp blished).

a nucle s

exp riment M.

G.

Nimo ya,

f o forwa d distribution

mas pion,

M.

Sekimot , Edwar s

neutrons se m

to absorption

and

El3

dep nd

and

M.

and

Tomizaw ,

I. G.

difers

E173; Kum-

Arai,

ThisPageIntolyLfBk

ThisPageIntolyLfBk This Page Intentionally Left Blank

K.

Hadron

’

20

dna Maruym

Nuclear

dna

Elsevir

The

Scien

Electromagni

Al

Probes

sthgir

A

fo

The

physic it

Toki,

resvd.

75

excita on

coupling

Physic , Weis

is role

fo

Univers ty double

model

gen ral y

delta

and

in

AN

beli v d

pion

The

This

first

motivated made

detail d [l]

signature,

that

+-

be both

A

nucleo s

pointed

nucleo s.

A’s

excita ion, sen it v

smal est

is 4 H e , [ 2 ] . This la). but p7r +

nucleo

work

for

above

coupling

at

rewol

30% result d

virtual in

degr s

60

fo

on

the

that

pres nt

the

is

not

diagr ms

consider

not

fo

MeV.

measur d in

fre dom, Noneth l s , a number

our

be n

On

mechanis

only +

decay

absorpti n

short

was diagr ms p

the absorpti n inter s ing

double

must

involed

reaction,

of

be

uniq e

so

pion

to

a A

+

valid ty

in

cros

the

be range

de- xcit , excita on

2AO since

the

decay.

such

should

a no relativ s c

to al

fo

close

cor elations

findgs.

section

two

diagr ms It

as

cros

emison

section

diagr ms

fo The

For

have the

two orde

and

AN

region,

In

the of

the

so

(SRC)

fo figure

the that

ap roximat on

12

mb cal u tion

may on

4He

this

for

the

lat er two in

the

type

lb).

both

40

nucleo s

reaction

is

by

fo

clarity, A’s, proces

on is

can this proces

sign f ca t

at

rewol

nuclear

In

increas gly VeM

at

uniq e

Wirzba

be

60

absorp-

7r

Arguments

the

claim

simplest

a rather the emis on sake fo

having

at

not

about is help d

for

to

N.

+

signature important

time.

sequ ntial

when

consituen

fi(

signature Schwesingr,

found

1980’~~

SU(3)

important a uniq e done

that

In

in

si

cal u tion

wer

fo

by

proces

find

leading

range,

A

the

unexp ctedly

excita ion;

en rgy

the

more

at la).

the

than a major

proces

delta

early

plays

si t o

nucleo +

the

simple t

stronge

figure

at

Can da

the resona c both proces. a n inc de t targets,

factories

nucle s.

perfo m d

AN with

in

the

four

27r

A -+

meson

shown

of

this

from

4N) Unfortuna ely,

AN

the

inter al y

they

pn

exotic,

f o inter s that in t o b e much NN proces in of requi nuclear pro tiona ely task, cleary, and otherwis

7r

A’s

that

cal u tion

be

the

at

involg

simultaneo s y

l iw

The

this

folwing

+

heavir

could

involg

out

proces

understanding so

whic

7r

has

S4S

SK

Regina,

is exp cted the AN

fo

both

the

Regina, pointed

excita on

shel . and

activ y

cal u ted 4He(7r,

en rgi s.

on

excita on

whic

A

deuterium.

for a detail d so

cal u tion

also

are

on

tail,

]l[

A

i t si clear t o the importance

nucle s

and

roles

via

be

to

pres nc

in out

that

phot absorpti n

great

A

excita on

and

cal u tions the

yb

of Wirzba

a major impl cation a fre deuteron target, t o b e placed complet y hig Fermi mo entum than i t ouldw be would indicate the have

of

kinematic four en rg tic it should two dif er nt requi s t o reach poten ial y enviro ment. The studied Brown figure 7r the play major interf nce for t h e doubtful ac ount 131.

wer

B.V

(Editors)

Huber"

"Department

tion.

htiw

Ohno

fo

physic

G.M.

Brown. quark Since domina t) could case MeV the en rgi s whic proces .

Physic H.

and

shown

case,

was

that

used en rgy

esp cial y

would

be in

67

Figure leading tion

1.

through

to

Pion

emis on

absorption

fo

formation

four

fo

through en rg tic

a virtual

formation p r

nucleo s.

fo pair.

a)

sen it ve t o the treatment f o SRC, since it involes mut al short range repulsion was treated with a and led t o a reduction in t h e A +4N cros A’s are in t al y in nucleo s as ociated with the si d o m i n a t l y i n a I = 2 or a S = 2 s t a e . The a tensor force acting on A N + A, while the reach d by t h e tensor force, and only one by spinthe tensor contribution comes from t h e fact that can be arbitra ily smal , and so can el ations betw n les sev r than in A N + NN transit ons. Thus, to the A mechanism comes from the tensor force, disrega d in t h e AN + NN transit on. To d a t e , relatively lit le prog es has be n made 4N proces i n pion absorption. Experim ntal y, required, and the trem ndous increas in t h e complexity a t thes en rgies, whic mask any pos ible signature. has also owerdl the expecta ions somewhat. For showed that inclus o f o proper nucleo deformation a sup res ion fo by 27% compared t o the Thes complicat ons contrast with the early et al. A msinahcem tsomla has t o eb ,tnes rp i t s ecna imoderp snoitpmus a tub of n a d r o G - h c s b e l C stneic f o in The only sign f ca t experimental evid nc for a t PSI. Rah v has come from studies fo ( 7 r , 2 ~ ) )+r7- ,-r7(C21 yields a t T , = 29 MeV using the that ther was a prop rtional y hig er number r72 production. fI ew compare the fundamental quasifre

(k)2

a A the

state

AN

four

range section.

nucleo s

fo

a relative

I =

S = the

whic

mo enta

2 sta es 2 sta es forces.

l/m, In a d i t o n , S-sta e,

wher

A

ident fy g si becaus Further

example,

in optim s c

fo the

have

the

SU(4)

a elpmis SU(4) the A mechanis et al. ]6[ c o m p a r e d CAL IOPE f o 2 ~ - ev nts reactions,

close

m,

thre

further

transfer ed

the

pion a 19

the

theoretical

the

-+

words i s ton

spectromet r,

cal u tions

krauq

than

A

together.

only

be open

enha cem nt

absorption pa er

fo

hig

by

transit on

fo a aterm

antic pated

A

the reaction

investiga on

Ab as

of pion and expect

are

safely

Schifer:

".ledom

of

A +

by

using "C(T-,~T-) ew

pion

by

chan els

contribution

us al y

two

A

AN

be role

Their MeV,

the

reach d

in

contributions

major

037 =

becaus intermediate

can

fo

decays, absorp-

b)

the

force

N

sub eq ntly

can

p tensor

that

this

in

earli

mechanism.

and

r7

it ap ears while this

A

-+

leads

+-

en rgy

[4]

Brown,

"The

ad

[5].

beam found

from a ratio

eoh and

to

-

noitaluc a

l uF AN-> n->p

-

---

(fig

(fig

la)

Ib

n)

w/of shel

03

.5 v

0

E 20

10

0

Figure pion,

cal u ted

2.

Total

cros by

section Schwesingr,

40 20

fo

the

60

4N) and 4He(7r,

Wirzba,

10

08

(MeV)

,E

proces Brown

120

versu

[2].

to al

en rgy

fo

the

incom g

fo

r n

r-A+

+-

while

)-r72

Clebsch-Gordan fo con lude

TAGX

are

twice

0.59 that

only

clear st

evid nc

that

at

body

mo entum

yield

-r72

of

INS

(0.3

A

ypn

+-

ac eptable

< 052

ev nts

cal u tion,

A

as

en rgy of

has

Asai

betw n

competing

MeV/c

]7[

from 570

the

whic 7r+-pnl

-+

ind v ual y wer

A

measur d production

Howevr,

mechanis betw n

to

phot absorpti n and

850

MeV,

neutron

as

the

is

the

observ d

d(y,

the mechanis :

ac ording

to

two

exp cted

charge yield

studies and

7r+-p)n

to

using

employd

reaction

a spinyield sta es. ratio, the Monte

a specta or

np-r+ 7 --f

fits

al.

with

A+ Anot

come

ratio contribute

r+7r-

+ 1p-r7+r7

npy

et

exp cted.

the

bal nced

mechanis

f 0.14)a~~.

excita on

(Toky ). with

space

resona c

a more

and

A++r

+-

phase

mas

many

=

beam a number

fo

as

provide

~ A A

delta

Four hig er

coefint

so

quasifre

yp

Double

an lysi

and

phot n

Quasifre

This mis ng

f 0. 14,

nearly

spectromet r a tag ed simulations

using Carlo

is

0.145 =

7r- +)

ther

a ratio As uming they The

ratio

f 0. 18, 0.86

=

observ d

,-i7(C21

so

p-752 rr+n +

+

the

,-r7(C21

isopn

Ao

7r-

+-

7r-p

t o the

entir ly

exp rim nt

could resolvd consi te

by kinematic

mic

the

exp riment. with

a number

observa l . the

f o overlap ing,

quasifre

Events

mechanis

with

78

Asai Wad .sgiF .sgiF 0

-

O%

Figure and

]9[

both

SAPHIR

A+ A-

3. with

(i.e the neutron with a combination was also ap lied using tag ed f o N * resona ces published. the a r e clear y fo The con lusi oA’ is t o that the A beam en rgy. is sim lar to The results Toki [9]. Like A transit ons t h e o,&N resona ce 4c). The result betw n the above this en rgy, Although the sections are The model deviates from was antic pated,

and

[8],

cros

and without

from the

the

and

ac eptably the

was

whic reproduced becaus

data

obtained

en rgy

data

pion shown taken

prompted

earli

40%

fo absorption into

in

fo

obtained

in by

figures

ac ount

the

by

MeV

further

promine c

the a detail d

quasifre

cros )r72

(T,

cal u tions,

4a)

the

[8].

via

and

cal u tion diagr ms

quite

on

SAPHIR

Althoug an lysi

with

the

4b).

excita on

this

In

sim lar

by model’s ad it on,

by Gomez-T j d r,

greater

iso p n.

with rewol

is

final

=

foundation to

result

experiment,

observ d,

7E

that

the

TAGX

wer

an lysi

TAGX of

at

col ab r tion

the

basi

rapidly

MeV/c

same

befor

the

section

exp riment

> 250

The

at

Oset

N*.

p,

A+ A-

that is exp cted

reaction

d(y,n+n-)n f o Gomez-T jedor,

with

consi ten is

1300

intermediate

contribu ons.

(Bon)

4 a)+b

the

requi s quite

are This

increas

nearly

from

ev nts

5 0821

(TAGX) al.

01

cal u tions

space

.la

te

4 a)+bc

90

(MeV)

the

experiments

ident f .

cal u tion

N*

importance

both be

5 7E result

,E

while

phase

750

hig er

quoted

TAGX types

and

7r+7r-p)n

beam

to

earli

fo fo

A

d(y,

with

contribution

A

quality.

ratio

the

a spectator),

this fo

mechanism at ain g

the

bet er

at

prelim nary

hig er weak

fo

to

phot n

sections

compared

was

700

te

and

en rgy.

710

at

contribution

shown

is shown in figure 3 . Ther si a construc ive interf nce below E-, z 820 VeM and a destructive interf nce si d u e t o t h e change f o igns f o t h e real part fo t h e "N p r o p a g t o r . N * diagram si s m a l , the wol en rgy experimental fo the with its ad it on. describes the phot production data u p t o 7 E = 08 MeV, in a steadily worse man er a t t h e hig er en rgi s. This discrepancy diagrams involg t h e virtual y p meson exchange cur ent,

Bon can

phot n

MeV,

contribution

tif

best

technique

but I t is also

increasing

[7]

Toki

is

Oset

that se n whic and

AN in

be

and

+-

fo

figure

diagrams

cros but such

19

I

74

\ = I

\

A

n

by

Figure such

se

as

4.

Gomez-T jedor,

in

as

that

one,

figure

rec ntly, det ction

experiment the

nuclear

MeV/c are also

ew

that dynamics,

the

tensor

fo

com unity.

fo

fo

diagrams

and

not

not

include .

Toki

include

[9].

include .

play

the

p diagrams

deuteron a more

d)

f I e w compare inde D- s t a e ,

in

diagrams

the

with

can ot

important

contribution

whic

model

including

be

was

fo

negl ct d

the

yd

the intermediate

result negl ct d

at

fo

A+ A-

Schwesingr

+

thes in

as

the

en rgy

thes

reaction meson ,

vector

en rgi s.

et

al.,

Ther

ew

cal u tions, is increas d. thes studies wer extende t o lower en rgy o n 3He by t h e TAGX ol-c Inclusive ,i:(eH3 7r+7r-) data wer obtained from 083 t o 70 eVM inc de t In t h e case f o the lowest en rgy, this is only 50 eVM above the absolute threshold. The det ction f o ad it onal prot ns, whic would have made more exclusiv in n a t u r e , was preclud by p r o t n rangeout in t h e t a r g e t , prot n mo entum det ction threshold. The result are shown in gen ral y consi ten with the deuteron data, after multip cation by 1.5 se that the data are in excs fo the Gomez-T j d r e t a l . predict on by t h e same factor), a iferncd hicw can ot b e explained by t h e i n reaction threshold betw n 2H a n d 3He. Analysi of hig er en rgy data from TAGX is stil underway. e w have se n that A mechanism d o inde play a n ident f abl role in reactions above x 05 MeV, although the importance f o their role has somewhat from the first optim s c expecta ions. Noneth l s , i t would study f o this mechanism can play a role i n our bet er understanding fo number f o topics whic have su tained inter st a s i t touches on a large Thes is ue include t h e role that repulsiv SRC play in s e t i n g the AN + AA proces , t h e interf nce f o N* and p r contributions, and force. to

induced

/ ;

Oset

wer

inclus o

dif er nc

7r+~-p) temper d

wer

[lo].

en rgy.

multiplication

con lusion,

question

expected

03 5, a n d MeV

4d),

the

the

7r+ -

strength AN

sample

this

s i also but also More laboration phot n

the and figure Howevr, (after x 52 3He(y. In 7r a n d be n ap ear nuclear in t h e the the

a).b),c)

08

A

-

-^p

d*1.5

d*1.5

9 with 9 o/w

’N

’N

I

04

.3 W

7 (d*l.5) 8 (d*l.5) 10 ) e H 3 ( Ref. .feR Ref.

o ef.R w Ref.

b 02

0 ’

’ - ’

053

Figure data

and

5.

calculations

The author col aborators work was fo Canada

3He(y,A p)

sup orted

cros

on

over

wishe

to

the

in

(NSERC).

last

thank part

by

years.

’

and the

I t was Natural

at

(after

the

TAGX

a very

’

650

(MeV)

obtained

target

INS

’

05

,E

sections

deuterium

ten

’

054

’

Sciens

’

TAGX

multip cation

enjoyabl

’

057

I ’

850

[lo],

col ab r tion and

Engi e r ng

and by

for valu b e

.1 5 ) .

and

compared

with

their Res arch

role exp rienc .

as

1.

3. 4. 5. 6. 7. 8. 9.

Y. 10.

G.E B. D. A. J.P A. M. Confer c , J.A. D. G .

Schwesing r, Ashery, Ab as, Rah v, Asai, Wad ,

Brown,

Schifer.

Gornez-T j dor,

Wat s.

H.

A.

Toki,

Wirzba,

W.

Weis.

J.P. chifer,S An . J . Phys. G 1 7 (19 ) Comrn. Nucl. Part. et a l . , Phys. Rev. et al., Z . Phys. 34 rep s nti g the SAPHIR Wil iamsburg, Virg n a, E. Oset, et al., Phys. Rev.

A.

G.E.

Rev. Let .

A

L18.

Phys.

C

Toki,

5

Phys.

Phys. Part.

Nucl. (19 )

6

(19 3)

H.

Wirzba,

Brown,

col ab r tion, 196 (19 7)

14

Sci. (1985)

Phys.

63

132B

1 8B

(1986)

Particles

(unpublished). 1832.

(1982)

(1983)

269.

207.

39.

15. 1279.

35.

Let .

Let .

Let .

346B

and (19 5)

Nuclei

International 240.

host Council

REF NCES 2.

the

This

and

K.

Hadron

’

20

Nuclear and

Maruym

and

Elsevir

The

Scien

neutral

.T-1

fo

+oE proces = -

the

+-n

.1

INTRODUCTION

stracted and vector cros ment ChPT cal u tion

yp diferncs

The be results

19 4,

Fuchs

meson sections with

Even

caused

pointed

the exp rimental contributions

the al.

near

those

can ot

perfo med cal u ted situation,

betw n

ifm-’

=

+oE

real, -0.87

an can

MI+

is x

the

10-3mLi.

contex

7r+

near

out cros

[4] result

diagr ms

that

section wer

ag in

with numerical

a yek

LET

converg

threshold

Such

mo entum

Eo+(yp

Korea

to

extract

chiral

Eo+

to

prot n

near on

imples

ac ount.

evn

a proces

be

is

left

in in

thres old

that

contribu on

rep oduce

el ctri

measur

whet r below

the

wol of

is exprsd

amplitude

drew

en rgy

conserv d

PCA .

consi ten ly

be with total

and

are

thres old as

7r+

charge

in

[6].

os

the

the

near

exchang

[7]

far,

rescat-

axi l

at

pro e ly

Howevr,

the

sub-

thres old

LET

dif enr t al go d

fi agre -

the the

becaus proces , fo

becaus

mas (1)

pion-ucle below

are

cur ent a reason,

’rn

is t h e

vector

at-

such

should

amplitude

the the result

trem ndous theorem(LET) For

the result

Their theory(ChPT)

Eo+ for

.ylwo s

our

dipole

to

by t a k i n g is edl that proces . Our = -2.15 x qk$;m3-01 frame f o cal u tion.

this

MI-

the parti l y a break

ac ur y.

perturbation to

the

cal u ted conlusi

and

resto d

p-wave

predict on

A role

is l ew

l ew

Korea

be n

a yek

pion into exp riment

520-714,

have

t-chan el.

the a pos ib l ty is based

LET

the improved

question

on

the

could

the

--+ )

than

fo

the

Eo+(yp 0.172fm

x qk$;m3-01

fo

[2,3].

7ro)p

fo plays

7.56

rap.

and

p(y,

taken

by

exact

120-749, Naju

for

=

the

a break

contribute

pro) = is l a r g e i.e

hypot esi

the Since

pro) +

+

Seoul

model

thres old

+-n

nn-+

u(nr+

0.19 makes

pole

thres old

lo p

-+

x 1;m3-01

Ef+

[5]

i q u(nn-+

26.

[l], a sen ation

to al

make the

fo this

in

the

phot production in

down.

prot n

Universty,

the PCA

pion

et

n+-n =

wher

broken

ew

from

that

4

Et+

hypot esi

amplitudes

The

physic t

Universty, Dongshi

in

the

Jeongb Yonsei

below

x 10-3m;:,

fo

on

T.

MI+

ac ount

81

resvd.

Physic ,

1.23

threshold.

neutral

In

and

into

Probes

rights Al

Physic , of

The

Electromagni (Editors)

phot production M.

bDepartment

tention might (PCA ) the

B.V

and

"Department

Eo+

htiw

onukO

pion

Cheon"

meson tering

Physic H.

-+

the

by

pro) 7r+

thres old.

scat ering one

orde

This

length, fo

magneti ude imag n ry

Eo+(yp

) ’ n n and mo entum

=

+-

q =

(2)

82

Henc, tum Notice proces. defin t

a question below

that

It a.nswer

arise

thres old

the

si

to

pro ag tion very

whet r inter s g

the

can

rescat ing

contribute

particle

to

question.

to

si car ying

an lyse

of

the

proces,

the

pion a real

carefuly

i.e

mo entu

the

car ying

the

an

real

imag n ry in

exp rim ntal

part

of

us al

rescat ering

result

moen-

amplitude. to

dnif

a

CAL U ATION

2.

si given

The

LET

predict on

as

Eo+(yp wher

the

pro)

+-

p

938. MeV. the Ther fo , Born

term

. The

and

us

the consider

Since take

wher

the has

A contrib ons

MfLet

in

be n

of

evalu te

The

and genral

The

=

(p2

pion

and Ai,

-

form

yb

pion

en rgy a set

mo enta.

estima ed

er w

as + f M ni b o t h

cal u ted

the

sevral

estima ed

amplitude

the to in

anom ly

our

disperon play

e2/4n

authors cal u tion.

an

si

cal u ted

=

the

=

theory

[9]

due

[lo].

of

linear

the Each

(3 )equations

contribu

the

1.79, result

to

the

and

to meson

vector

Althoug

4,

the

the the

exchang

rank

on-shel

to

be -6.31 =

BL

exp rim ntal s i describ

coupling

saw

The

x 10-3m;ikq

the

pole

us al y

result ,

yb

phot n

.]8[

x lOV3m;:kq

negl ct d.

model

term

amplitude,

resonac. as

,F

has we

polariz t n frame

=

On

x 10-3m;i.

4.17

using

M

and

theory

=

vector

(3) cal u tion.

+0.15

the

centr-ofmas

Nn

135MeV =

M&

term

si t h e

ip

of

-fM

are meson

coupling

rep oduc

m,o

fo

thres old

x 10-3m;i,

x 10-3m;i.

framewok

at

vector is

given

in

k]Fz+i(a.I;)(i.G)F3+i(g’~)(El.$)F4

(~.G)o.[Elx

to

in

=

reaction

-2.7 =

u-chanels

, tensor role

Vector

amplitude

up

x 10-3m;:kq

and

s-

-0.72 in

the

pro

+-

O(p3)] Pct

si

l ehs-f o

3.1

+

K ~ )

137,

eq.(2)

+fE

=

[8,10 ]

importan

+ in

term

phot r duction

fo

given

py

rof

1 -p2(3 2

pseudotnr

+ the

of

yb

F=Z(O.E)FI

rof

amplitudes

si a n t i s y m e t r i c

E~,,,~

t

ew

x .qk:;m3-01

it si expctd it into ac ount

0. 8, =

amplitudes

+

[-p

model,

be n

chan el

dipole

Ef+

rescat ering

dipole

elctri

f2/4n

amplitude

1.84

=

t-

quark

the

(4nm,+)-lef =

m,o/M =

basi Magnetic

of

the (5)

Her ,

can

be

k and conetd

are

the

to

unit

the

vectors

invar t

of

the amplitudes

phot n

38

wher

+

(rn

in t h e gPv/4r coupling

close

whic

+

to

imples

det rmine

yb

of those the above wnyg = si t o sevig a gyKp =

+{EA

the

oT

contribu ons

-0.983

vert x

Notice show

result. si pd contribut ons in

compared

With

+

the

are

pd,

to

other

thes

AEi+

the

&.&

=

must defict values,

+

(-0.62 =

if

si

for value us

thes

&

r(p0

gwr/v

whic with

mb), (m2 ri.4/TLg

sevig

i.e

2.38)

has

defict and

ratio consta

and

0. 14nr

elihw

amplitude

conlude 1.76

=

[13], si

a large are

10. 06nm.

contribu on the

Apd gynP

oT negatv

at

thres old

are

being

Our at

+0. 25nm, to

than The

value

be

estima es

compensat

"’7) gynw

of

0.5, The

data very

whic

i.e (10)

RESULT

3.

The

evaw-s

Ehh, =

Mi-

M1+

+oE

amplitude

+ E,$F

-2. 7 +3.1 -6.31

Born

for

AEr+

+4.17 +1.84

neutral

+ (-2.7

=

A(123 )

the

0

(p,w)

0.26 2.3

1.76

pion 1.76)

phot r duc ion

at

x :im3-01

Rescat . 0.72

0

0

=

-2.15

+7.56

-1.23

-0.51

thres old

yields

Sum

x 10-3mi .

1

Exp. -1.32 +7.41 -3.59

(I)

)1 (

hO.l

I

Exp. -1.3 IM 10.2 =

)1 (

80. f

f 0.15

be i.e

dpA

=

the

this The

as

x .:im3-01

=

=

might

least,

negativ ,

1. 2,

at

mo ent. defict

=

6.1

D,

* =

+-

3.18

=

This [13,4].

consta

er o .

(0.067f0.0 7)MeV

undet rmined

magnetic

smaler

gwT

=

r(w

result

0.1 =

10. 9,

=

=

w

and coupling

The

"-7)

cur ents have

(mi/2W,)

Vpg/Tpg

whic

rather

+

f 1.5, T : g

gwv and

widths

=

rof

ew ew

x 10-3mi

2.4, =

of

yrw

:pA sign

0.1 =

lwr?yg/ps I deut ron

The

8.1 =

+-

the

si ositvep = +0. 14nml Thus, the AEr+

find

decay

r(p-

the

coupling

a positve

the

:m =

q2)lI2.

induce

TOY)

t-

[13],

C

+

f 0. 3 )MeV.

lwr?yg/p, l

yrp

Ap:

ew

[12]

2.1,

+ =

si in

the

Apd

as

(0.18

examin

h0. 19nm

f0.013nm. =

find =

whic have

hand,

ew

evalu t d

of let from

A&

ew

data precison

Their sign

sign ,

0.843nm =

result

Their

The

20.5

roy) ratio

-+

that the a bet er

their

know

are

Ez

and

=

Her,

gYTP,

r(p0

f0.0983.

=

On

and

egy?rv/m,o(m~o k2)l 2 =

+ g&/4~

16.05 and

=

f0.130.

of

defict

reason bl

=

Xv

(m2 enpircaly

and

gynw

value

AE" =

gpT

=

are

0.6

&

gynp of .3 decay gyKp SU(3)

neglct

f0.31 .

large

El

and

constants, f 0. 42)MeV and result "-7

(0.71 10.313 SU(3)

stage. exp rimental caused

0.5 =

2.63

p

m,+/(8rWs), with =

NNV

-

QpV

for

5

E,)’I2

84

Eo+

The amplitude yp -+ 7r+n I t si obvi us amplitude by t h e dot ed

E;

0

(7) Thus,

and

near tering rescat ering

7r+

(8).

the

defin

lM taken

values

+1E3 =

I!41

proces ,

result

the

The

from

proces

resp ctiv ly.

The

vector

are

for

solid below

curve

taking

begin g

does

taking i t yields

15 0

dipole

si

not

ac ount

agre

ac ount

shown fo

the

fo the a dot-dashed the experimental

by

with

rescat ering

rescat ering

curve

result.

proc es

in

proces ,

Fig.1

The

is is shown

amplitude

rescat ering 5.

+

and

Experim n-

meson

ML

the

and

cros

the

- Ml-. dot ed

ob-

the dipole

Adl+ x

threshold.

thes

with

2.

dot ed resp ctiv ly.

Total the the

cusp

s-wave

refs.

3,

2,

amplitudes

10-3m;$kq

cros

curves

and

amplitudes

efct

Experimental

The contribution

MK

be =

found

The

obtained due dashed

to

the

data

5. can

are

sections.

are

as

evaluated 2.3

curve are

10-3m;$kq. x

without

solid rescat-

rep-

with

curves

result

cal u ted figures,

are The

the

taken

with

Eqs.

x 10-~~;;kq.

This

section

7 ~ +

to

-2.15 =

jFrom

0.26 =

magnetic

M1+

Figure and and tering, res nt rescat ering. from

curve

-1vi total

1

ampli-

ref.

the

the

without

(f,i2)

dashed

x 10-~~;3~,

2 show

and

kq

dot-dashed

Eo+

with

amplitude.

fo

The

The

the

and

the

x 10-~ ; :,

32.1-

MI.

threshold.

total

7.56

threshold.

without

Fig.1,

O

are

the are

in

dot-dashed in

=

Electromagnetic and

.1 Eo+ curves without

=

Figure

E&

threshold

0.05

results

M~+ eW

+

near

mentio ed

the threshold

at

curve

1

the

Contributions

TOP,

that

+oE

;E =

Figure tudes, dot ed tained below repres nts tal

-+

(13) is in with obtained one dashed

Fig.

1 with

thes may

without curve

confirm

a dashed

el ctromagnetic

and in

Fig.

the

curve. with the exist nce 2 is t h e

amplitude s-wave

rescat-

fo

the

85

01

0

2

Q

L

40 02

9

PION

Figure tained lated from contribut on with improved

of

The curve can solid ew Althoug pres nt domina ce. the

the

Figure solid

rec nt

rep sent

se

rho

meson, amplitude

’ =" + L O E This

value

3 hows ac ur y curve

cal u tion,

ew

the

swoh dot ed Since

have

f

si somewhat

the the

shifted

the

result

AEr+

Ehh+

ef ct diferntal

and

gpT

i.e Since

the

curves dot ed =

with

9.73

= =

saw

curves

+

AEr+(-2. 7 esolc

0.93) to

downar

rof

Fuchs

the used

case from

given

dot ed

151.

result empircal

7E

exp rim ntal

=

x i;m3-01

3.7

woleb

15 .7MeV value

value based in

are

rof our

while T+

much

bet er

the

gpT/gpV

on previous

the

7r+

and

Ther fo ,

152. MeV =

tensor

the

result the

thres old.

su(3)

x 10-3mi .

-1.34

consi te

data previous

the

taken

are

the ]5[

obcalu-

result

woleb only

are

are

data

with

=

smal

cures curves

Our

al. contribu on,

ap e rs fo

gpT/gpV

eq.(l2).

proces.

et

contribu

=

in

recnt

the rather

0.93 =

and dashe

Experim ntal

compared

her

x 10-3mi

that

with

rescat ing exp rim ntal

from

AE&

yb

the the

discue

The

(14).

rs cat ering

rescat ering

solid

eq.

the

an lysi

+

&EA

in

section

with

evalu t d evalu t d

to

withou

the

The

rescat ing.

obtained cros

agre

16.05 previous

due globay

result

section.

the given

data

rescat ering

our

gpT

cros

with

cusp

any used

and

amplitude

the

exp rim ntal

the

not

with

with

that

curves.

do

ref.[5]

Diferntial

.3 withou

1"I,,e ANGLE

cal u tion,

[5],

whic

[2].

dot ed thres old, 6.1

eW

than

coupling

the

in

the

vector

(14)

it may

be

sup o ed

that

86

if gpT proces threshold Howev r, a s si se n either. =

below

9.73

in

is u s e d , the

en rgy the

the can

improved

Fig.

7r+

reason bly

3.

experimental

threshold. data

Agre m nt

at

with

be

7E

result

Inde d, reproduced. =

15 .7MeV

the

can

the

dif er nt al

f o +oE

data

be The

explained result

and

cros

152.5MeV

shown

without are

shown

in

Fig.2

the

sections can

by

not

could

be not

dashed

rescat ering

up

to

reproduced, be

the curves.

+r

sati f ed

CON LUSI

4.

10-3m;ikq

Our

results

pion car ying a s a physical the rec nt remains

are

at

+oE

the

an

valid.

imaginary

meani gful

experimental

= 7r+

-1.23

threshold.

x 10-3m;i,

proces .

results

mo entum

eW

are below

Our consi ten

are

MI+ led

=

to

a con lusi

the

pres nt

7.56

x 10-3m;ikq

threshold

7r+

investiga on

with

that

the

LET

and

leads

and

the

can

play the

Mirescat ering

to

PCAC

=

important a con lusi

REF NC S

hypot esi

2. 3.

.1

4.

5. 6. 7. 8. 9.

10. .1 12. 13. 14.

P. d e R . Beck J. C. B. G . M . Fuchs V. Bernard, A. N . I . Blomqvist J . Wes F. A . T . Schafer T . Ericson R. J . M. Chemtob,

Baenst, Bergstrom Yu,

et et

Il-T.

Adler,

and

B. and and

Phys.

Phys.

Phys. Cheon

al., N.

Kam l, Ber nds,

Nucl.

al.,

Kaiser

Phys.

and

A.

E.

Zumino, W. W.

et

al.,

Phys. Rev. J . Laget, Don achie Weis , Weis , Rev. J . Moniz

B24,

Rev. and Let . and

63

Let .

Phys.

Rev. M.

U.

Let .

Nucl. 14 ,

T.

B368,

Meis n r,

63,

and Pion

and

149 ( 6 ). M.

Phys.

(1970).

02

D. L. Nuclei , Rho,

A531,

(19 0). Phys.

Z. A280,

37B,

and

R1052( 9 6). J.

(19 6).

2346(198 ).

Phys.

Let .

184

C53,

Jeong,

Nucl.

Phys.

65,

Weav r,

Phys.

SOC.

95

Phys.

Japan

C70,

483

405

(197 ).

Clarendo Rev.

87

(19 4).

(19 6).

(197 ). Nucl.

520

63,

Phys.

(19 ).

B4,

103

Pres , C10,

34

Oxford (1974).

(1967). 198.

-2.15

of

roles

the that

x

Hadron K.

’

and Maruym

02

Nuclear and

Elsevir

Scien

Phot neutron Compton Toykaw,

305-86,

Electromagni

lA

Probes resvd.

rights

measurem nt

laser H.

Physic ,

rate

Univers ty,

yb

eB’

Yam gat

fo

means

and

Okamot

M.

invers

Ohta

with

Sak i,

the

MeV

step

Result

data

Higash n da,

Osak

wer of

taken

for

a-proces , with

measur d phot n other

Japan

1-4, Umezon

for

source.

the

Kobe

59-870,

Labor t y,

sections first

8-91,

1-2,

, Electro echni al

Div.

cros a laser- ct on f o the

supernovae.

T.

Gakuencho

Japan

using

phot ns

Akimune,

Kona

Radiation

on

Ohgakic

Univers ty,

Phot neutron 4 . 0 VeM the reaction core- l aps in c o m p a r i s o n

87

Yonezaw ,

H.

fo

Japan

’Quantum Ibar ki

(Editors)

section fo

and

Pref cture

eB’

Thes

Q(m, 5/2-, phot n

1/2+,

y)’Be.

in 1/2-,

the cros and

source .

en rgy in

Tsuk ba, range

section a neutrino-driven 5/2+

from

are

sta es

1.8

rel vant

are

to to fo

wind

pres nt d

INTRODUCTION

1.

two

B.V

Y.

bOsak

the proces d folwed than nuclei

htiw

cros

Utsunomiya, Fujish ro

De p a r t m e n t 658-01,

O h 0

scat ering

H. M. H. a

Physic

H.

The

neutrino-driven

r-p oces the

by

into

[l].

9Be

the

triple beyond is a losey-bund

In

j6Fe

Q

’Be(a,

proces . for

through

wind

this

formed

rapidly Q(Q

n)12C. r-p oces .

This sub eq nt

The

n,

in

expandi g sequ nc

core-laps

enviro ment,

yb reaction

of

supernova bridg n

C"

network

production

mas

n-

gaps

consti uents

+

alone

+

can

nuclear

form

A

proce ds

is consider

sy tem consi t g f o two a’s a bound sy tem. The lifet m s x x sec, respctivly. Thre adj cent ecs and 0.97 Q n , at 1.6 5 eVM for 8Be n and a t 2.467 MeV MeV for Q the lifet m s, the synthesi f o 9Be is consider t o proce d more than through jHe in two ucesiv binary proces. The ternary a minor role. Resona c near thes thres old det rmine the Resona c par met rs f o thes sta es can be obtained yb phot dis ntegra ing Previously, phot neutron cros section for e B ’ wer measur d kinds f o real phot n sources, Brems trahlung and radio ct ve measur ments with a phot n difernc method ackedl great ac ur y resoluti n [2]. Measur ments with radio ct ve isot pes (24Na, Io5Ru, lZ4Sb, 142, Pr and 20GBi) wer lim ted below 2.75 VeM eB’

may

and

and thres old

+

domina tly rate isot pes. ,1A"

.18-3[

be

a-rich

an

ideal site orf material si first 5 and 8 , whic si more ficently t o produce eds

=

a neutron. 5He

fo for

and

proces

fo

near

the thres old

38Cl,

exist

+

5He

Low-lying

due

eB’

Non In

Q.

is ikely eB’ Brems trahlung to j8Co,

through ’Be. po r

at

1.573

view to

synthesi .

any

fo

are

play

using G5Ni,

8Be

1.1

of

two en rgy sta es

8 Y,

in

8

eB

er w

lated data

also

the for

al

first resonac

in

state states

EXP RIMENTAL

2. 2.1.

y-ra Invers

TERAS in

the

rof cm

ratio, grated

A

scat ering only

thres old

413

light

VeM

15 in

Neutron minutes producing

length). deut rons

laser

10

% to

col imated

colisn

mCi I t saw

the

and

scat ering

linear y

throug

into

point 9Be er w

the

time to at

at

24.1

Background

the the

40K with

range

polarized

optical

yrev

[9,10].

.ylkaew

(1/2+,

fo

9 .5

neutron er w

The to al

with n

the det c ion

24Na mixed

The

4572

thermal 24Na

and

in

the

ac ur y

averg

,rev woH

No

5/2-,

with Vek produce

beta-d c y

of

enrichm t

two Neutron

as cmHg

single

virtual

measur nt 5/2+).

1/2-,

2 cm3

length) moderati n

directly

of

and of

65 a time- nd p t

phot ns

po uprovide

saw D20 transit on Vek

to

phot n

in

at

neutro s.

cm

in

4+

alumin

yb Resarch to

state

Contribu ons

diamet r) in

DC-beam

2+

in

contai er

pulse the

car ied

measur nt

with

at

polyethn

saw

(2

frequncy

separ tely

sample

a 9.4 Thes f o other

measur d

and pasing varied

MeV. m

y

from

a moderati n

rof

saw

in

saw a minor

with

diamet r

x

y rays sta es

6

phot n

befor

a DC and

agred

of

in

taken

(IkHz)

Kyot

%

ring mea-

the det rmined

of

a

2.5

cube.

out

measur d

mc

1 zHk

a con e tri

diamet r

mg

5.

a luxf er w

-ueN

made

saw

LEMPS

yb saw

4.0

stor-

ir ad te . D N :06-4358

in

that er w

-

l show

(2 obtained

a 05 Insti ute

transit on.

saw

enrgy

en rgy-calib ted

6oC .

in

comp ne t,

Reactor 24Mg

enrgy

cm polyethn

from

at VeM

saw

the with

pro e ti s

produce kcolb of

beam

source,

1.8

peak

the Fig.

er w

neutrons

Pb

fo

a 03

er w per

ir ad ting

the

source

in

spectrum obtained

saw

Electron y-ra

det c or

and

made

horizntaly,

spectra

pulsed-

the

(MITSUB H

time

module.

phot ns measur nt

an

the

of

thick

operat d also

in typical

beam

saw

range

enrgy

and

a BGO

Pile-up

dnuorgkcab the

counters emb d

[12].

el ctrons

quasi-mon chr ati

phot n

beam

The

saw

mc

phot ns.

CAT

phot ns

of 5 .%

hours)

in

verticaly

with

number a ingles

(2.5

A ful a standard

VeM

sy tem

enrgy

a 02

produces

%. light

depolariz .

laser as

relativ s c wen

laser the

type.

line.

fo

562

with

in

on

(ETL)

a encil-kp of a w e f

spectrom

3FB

ORTEC

neutrons,

caled

l ew

each

result

neutrons

Unpolarized

This

as

The

and coaxil

06

[l ].

y rays

Indep t

15

y rays

light.

incdet

Labor t y VeM

used.

diamet r

esu

neutrons

The

saw

beam

number

time.

1T802

ef ctiv an

of

el ctrons

%

ycnei f (half-ie

with

four

with

dnuorge of

04 si vailbe resolutin

and

measur nt.

det c ed

end

1 to

in

axis.

with

phot ns

elmnt

produce

det c ion

laser

anti-Compt n

nm)

to

det c or

located,

1 kHz. spectra The

acquis t on

an

cm

beam

enrgy

2 m

betwn

of

rod x

1053 an

VeM

source),

and

=

574

pure-G source

from with

(A

neutron of

Electro hni al

range phot n

VeM

invest ga d

Nd:YLF

2.16

of enrgy

phot ns/ ec m 2

wer

production

Compt n

a 15 cm3 natural A 4 cm thick trons er w measur d cm in diamet r The 3FB counters a t 7.5 cm from sured in l ms time distr bu ion. contribut on Incide t phot ns length) placed beam pulsed from the pile-u with a DC b e a m . and the data beam, in whic after each measur nt. t o each other 2.2.

el ctron

(1/2+) near

METHOD

age ring y rays (laser- ct on of l o 4 previously A produce polarized from rays head-on with with

versity.

invest ga d excit d

branchi g

NaOH

in

dis nte-

-inU

24Mg

x

4

89

lo:

*t

11 I

Figure

about time- nd pe ntly inter s .

to

The

neutron

bath flux (MITSUB H neutrons ground Time of production The saw coverd eficny uncertain y of t h e Fig. The MeV. MCNP

saw

method

had

neutrons

during

counters. smal The

thus

stem d

2 show

en rgy [15].

saw

The

evif

The

saw

also

the mc

saw

placed contribut on

to al

done

measur d

dep n c

each

and

ycnei f

with

17.5 the

562

sy tema ic

1.7

% the

of

in

det rminat on

the ycnei f e

a 25Cf

RESULT

3.

Cros

section

er w

obtained

with

a formula

in

the

the x

a t t h e cent r 03 second, of ackgroundb Vek neutrons

with of

same

saw

2.83

that

of

neutron at

mc with

rof

time dist ngu hed

becaus

Vek

be

rof 1 %

placed

to

to

rof ycnei f

562

The

neutrons

cleary

saw The

distr bution

1 ms.

are

measur nt

from

counter

the

Background

be n

measur d

the times,

2.5

time

si

neglctd

fo source

from

det rmined

det rmined 3FB

scale

er w

er w source

Ful

p sec.

ND852-60).

separ tely

neutron

perfo m d

041

inte s y [13].

measur d

elaps d

ycnei f

production

absolute

Moderat.in

.1

cube.

i

Number

Chan el

len

’"1

l

" " " " ’

" " ’

cor e t d

smal centr 2.5

calibr t on

lo3

standard

counter

of

source

ar ived

cm

step

det c or saw

esohw

cal u ted

der voc

from

phot neu rons

saw

of

graphite

of

with

the The

saw

as averg

0. 9

moderation

a polyeth3FB

si

counters of

ratios. liter smal

with

water a 1.5

cm3

counter elip at yb a 5 m ources inte s y

det c or.

&

the

at

det rmined

a 04

bare

of

in

rof

branchi g source

for. counts/sec/4~. t h e neutron with wot neutrons saw 1.67 in neutron

er o neutron

neutrons

consta

3FB very

counti g,

source a functio

counters

% per inte s y.

with

neutron

ETL

the

bath.

3FB

thick

3FB of

a Monte

counter. in

neutron

cadmiu .

enrgy

counter thermal Back-

the counti g

and

The

5 %

[14].

at

A neutron smal .

rof

water

Neutron

det c ion

time two

CdThe

calibr t on enrgy. Carlo

si .352 code

90

12 ,

1 8

.

.

.

fo

wher the det ction target.

wher material. that (solid excita on-e rgy hig -en rgy 1.6 5-MeV flux spread Cur ently, (^/-decay

Pin

BGO

eficny.

p

Fig.

2. 24NaOH

the

+

eficny

is t h e det ctor,

is t h e The 3 show

Neutron

The

number

total at enuation

Nt

was

is t h e A cor e tion

y-at enuation

D2O

fo

cal u ted

and

neutrons number

coefint

.

.

.

.

.

.

.

01

was

det cted,

factor,

coefint

was

.

.

.

MCNP

.

.

target

.

02

0 51

neutron

the

nuclei

f , was

0 52

a functio

det rmined

en rgy

MCNP

is

,N

9Be,

and

from

cm2,

rof

[16].

dep ndence

Monte

the

per

ne d

in

taken

.

Cal.

as The

.

Carlo

eficny with

fo

.

E (keV)

exp rimental y

25 Cf.

.

Monte

05

det ction eficny

.

+ D2 0

24NaOH

0

Figure en rgy.

.

number the

t is t h e

with

fo

neutron sources

Carlo

fo

code.

fo

&,(En)

and measurem nt

length

y rays

fo

is t h e with

the

inc de t

neutron

eB’

on a thick

target

a function f o y en rgy. Note with those for polarized ones cir les) within sta istical The pres nt measur ment ful y coverd the range f o thre resona ces (5/2-, 1/2-. 5/2+), hilew i t cover d only a tail fo the first excit d state (1/2+). This si becaus as ap roaching t o the threshold, it b e c a m e difcult t o ac ur tely evalu te what fraction f o t h e y-ray lay a b o v e t h e neutron threshold. A Monte Carlo cal u tion f o t h e asym etric en rgy f o LEMPS may help de uc the nec s ary y flux. This wil b e done in t h e fut re. a least- quare itf t o t h e data si i n prog es t o de uc resona ce par met rs widths etc.) towards a n evalu tion fo the rel vant reaction rate. results

for

measur d unpolarized

phot neutron

y

rays uncertain es.

(open

cros

cir les)

sections

agre

as

91 /-

2.0

t 1.5

tnes rP

I

stlu er )dezira1opnu(stl er Presnt

o

orihs juF B.Hamersh

+

i

l es uR.B J.HGibons W.John nosb kaJ o A N

.....

,/

/

,,

(polarized) te

al.

te

aL(1962)

RI

te )3591(. a (1948) t e al.(195)

.la

te te

(1982)

RI

(196) al.

RI

RI

RI

s merB

/

,8

.. O O i Y

’ ’

1.5

’

2.0

"

"

’

2.5

’ ’

E

Figure results radio ct ve

the

Phot neutron

prec ding

isot pes

are

cros measur ments also

3.0

"

" "

’

3.5

"

’

’

4.0

’

’ "

4.5

(MeV) r

section

for with

shown.

gBe.

For

Brems trahlung

comparison,

and

ACKNOWLEDGMENT

4.

for

3. fo

"

eW Ogaw

are his

techni al

(Electro echni al standard Foundat

indebted (Kinki

Univers ty)

as i tance

Mr.

K. for

Laboratory) pile.

graphite

ion.

to

Okamot the

in

This

his

ir adiation help for

work

was

(Res arch his

NaOH

fo

in run ing co peration sup orted

Reactor the

in

yb

MCNP the

Insti ute

with the

det ctor

Japan

thermal

fo code, Private

REF NC S .1 2. 3. 4. 5. 6. 7. 8. 9.

S.E. M.K. B. B. J.H. W. M.

Wosley Rus el Hamer sh John Fujish ro Fujish ro

M.

10.

H.-G G.

Kuechl r

and

Jakobson, Gib ons

e t al., and

Clerc

et J.M.

and

e t al., e t al., e t al., e t al.,

Phys. Phys.

R.D. C.

al.,

Pros e , Nucl.

Z.

Rev. Phys.

Can. Can. Phys.

Hof man, Rev. Kimbal ,

123 73

(1948)

Rev.

Phys. J . Phys. J . Phys. Phys.

(196 ) 14

Astrophys. 54.

Phys. Rev.

A326

60 A120

(195 ) (1982) (1983)

61 (1987)

J . 395 29.

Rev. 163

13 9.

(1968) 47.

90 (1967)

(1953)

(19 2)

1672.

1579. 41.

20.

958.

1063.

and calibr t on

neutrons,

Kyot

Univers ty)

Schol

to

Dr .

to Prom tion

K. with

Mr.

Kudo

Y. the

92

.1 12. 13. 14. 15.

16.

H.

H. Experim ntal weN Y. J.F 4B, Engi e r Blizard, (Springe -V la

Toykaw

Ohgaki York,

Inoue Las

Briesm ter,

e t a l . , Nucl. e t al., IE Tran. nuclear hysic,p YN 1978) p . .5 4 e t a l . , Bul . Electro ech. MCNP, Alamos Nation l Compendium A.B Chilton, M. weN kroY

Instr.

A Gen ral Labor t y, on Radi t on Grotenhuis, Inc.

Nucl.

and Sci.

.loV

1968)

Lab.

Methods 2,

38

Monte

edit 31 197. p.

A.

in (19)

(1967) Schieldng, 173.

Honig,

yb

Carlo

Phys.

Res.

.683

E. 60.

2 4A

Segr

(John,

N-Particle Th.

(19 )

95.

&

Wiley Transport

.loV

A.

,1 edit Jaeg r,

Son,

Inc.,

by

Code, and

R.G

H.

Version Jaeg r,

Eisenlohr

E.P

Hadron

K.

’

dna

20

Maruym

Nuclear

dna

Elsevir

Nuclear

Scien

B.V

Electromagni (Editors)

Al

Probes

sthgir

resvd.

Nuclear

A odelm t o cal u ate The multis ep a nucle s, excit d residual nism . Comp ne ts exp rimental Synchrot n

of

Res arch,

The

el ctromagne ic

the

model

(2)

and

inclusve intra uclear

includes

nuclei

data

CERN

describ of

obtained

spectrum

wher x =

A,

*Sup orted te-mail:

=

to RHIC

play

of

the

model

phot ns

at

theor tical an

v/c

%

,1

contai s

of

ultra el tiv s c

>

fine by:

by

INTAS

data

The

al

spends

)1

structure

felowship

mean

yb

with

heavy-ion

coliders

obtained

models

role of

equivalnt

of

Scien,

2137

relativ s c

heavy and

produce

double

deif r v

yb

nois f phot ns

respctivly.

in

The of

dis oc at n

a short

frequncis

constant,

number

68- 9 FSY

colisn proces

of

ielcun

of

moving

time

up

to phot nuclear

KO

at

At

the

and

on

5 1/R2,

Q2

to

phot ns

the

near

proces.

the maxiu

absor ed

1K

of

si may

phot ns.

a uclesn Due real, in exprimnts

almost describng

nucles the

char te is c

of

of

ions such

hadrons

virtual

and

heavy

multifrag en tio

Rus ia

whic

interac o s

and

and

comparisn

,wocs M makes phot n

(3) of

absorpti n

sta i cal

cal u tion ions

at

it posible pres nt d.

si

yb

decay result

mecha-

KE -Tan shi

of

with

MODEL

dleif phot ns.

are

single of

evapor ti n,

er w

monergtic

ac el r to ,

[2,3].

el ctromagne ic

(y

a si t h e

UR.KSTIORT.RNI.02LA@VONHCINEHSP

phot ns

reaction

the

)1(

excita on

LHC method Coulmb

Academy

THE

important

equivalnt

exclusiv

casde

SP

Coul mb

an

and

such

E,b/(yp). si defin

interac o

and

OF relativ s c

of Lorentz-bsd the absorption the nucle s, phot nuclear ap ropriate the pro e ti s Since

virtual

Rus ian

DE S C R I P T O N

exp ct d coliders,

yb

* t

for

.1

93

induce

Pshenicov"

"Insti ute

P

with Okuno

dis ntegration I.A

Weizsackr-lm

Physic

H.

a nwo k-l e ultra e iv st c

be

Acording

the cohernt with

colisn

the

impact

are

phenom describ

in

to partne

heavy

the

this

nature of R si t h e uclearn real monergtic reactions aym par met r

colisn

partner,

enrgy

the

yb

modife

the

may

phot n

radius.

-

virtual l/At

partner

emison phot ns

used

b with the

les B

the

be

be

E F

colisn

framewok

method

[l]. nuclei

functio s

at impact

treated

of

si

wen

the yb

Ther fo to

the

It

and

predict

-

phot n

of

velocity

y/R:

mas

and

as

94

plicty

wher

(E,)

O A ~

from

the

As uming

phot neu ron rn(b),

proces

with

si the Eq.(2), rof

[4]

the

The dis ntegration to diferntal other ELectromagn ic the cleon nary menta ion ceds (SM ) The fragments decay mechanis 2.

place

)lE( ’!f values

be

cal u ted

In intra uclear

ro

nois f

competi on

fo

[6].

yN d2a/dRdP old [5]. in Ref.

"’,f

7rN,

+-

The ]5[

the

nuclear

of

fo with

spectra

yN

also

are

chanel

for

i :

functio s:

N(2) E1,

creat d

-+

avilbe

E2) single

defin

E2)

model.

produce

fast

and

when

and

light

the via residual of

si

evapor ti n

and

mechanis

=

fo

and

produce

[6]

at

the

describ

n

coalesn

the

cal u tion

excita on

fast

and set

particles of

y(np) have exp rim ntal

@,

of

yb

with

the

may s i lsoa of fast

take

schem

describ

of

+ T-,

and np

to 7 and

of

place

nucleos

A 5 16

yam

the

and

mean second-r

multi-

b)N(E2, ratios

the

enrgy

starting

,1E(N)b(m-ebd

include Monte

with first-

interac ion.

with

si treated

for may

transve are

sta i cal

7

rapid ty,

the after nucleos

stage

obtained

the

absorpti n,

LIGHTES Due

complex

exprsion

the

a later

nuclei

E7,

on

branchi g

phot n

rof

nois f

enrgy, prot ns

Simlar

the

code

AND

phot n phot absorption. Nr72

as double

particles

sevral (RELDIS) particles the evapor ti n f!2)

and

section

absorpti n

cal u ted

spectral

NUCLEONS

the

pions

multis ep

nuclei

evapor ti n

details

on

the

of

[5],

pair

OF in

multipho n

phot n

and

Other

EMIS ON Dependig

of

fi(2) E1,

dominates elis f

excit d

i in our

DISsociatn

multifrag en tio

be

section

double

7 MeV.

N

the

b),

yb

ro

may higly

and

and

cas de

proces 3 - 4 eV/nucloM [6]. roF

disocatn

EYin

cros

bmtn

obtain

nuclear

cros

,lE(N)b "-e d

chan el

to

rof

phot abs r ion

Dc,

distr bu ions

vari bles.

orde

to al

at

distr bution integral

single

1

bmtn

thres old

the

a particular

r72 =

ap ro iate

Poisn

gniwol f

N(l)(El)

the

be in

Carlo

phot n and

befor

residual multifragmenta ion or

the

Relativ s c on

fragments,

The

multifrag-

after SM.

in

Refs.

Fermi

have

rof

a wen

d , t , 3He yb t h e

found

consider

writ en

nucle s,

into

be

mo entu

simulation, absorpti n

lightes

the respctivly,

b).

ro

4He

The

and

namely,

a nu-

E*,

the

lightes

break-up

[4,5 8].

fison.

the

the shapes data

cal u ted p predict

contribu s

,A

number, above at

041

yb

the

difernt double

5 7E

the

pion

fo

sevral model

5 01

diferntal

proces

[7].

The

production

er w VeM

take mechanis: compared

spectra thres includ g

-ib -xe

model

FRAGMENTS mas

the

59

the descript on colisn

data

obtained

Fast

hadrons

the

hig

en rgy nucleos

of si e m i t d

angles.

isotr p c.

Becaus

deut ron

si

Y-2

>

the

obtained.

after

the

nucleos

bar ie the

phot n yb in

phot abs r ion

1.3-GeV

means light

spectra

Electron absorpti n

leading

of nuclei

is explaind

to

on

the

On

+ MeV)

+ C

+ d

the

of

yb mechanis. of

in t a e

heating emison

rates

the

A sati f c ory

Synchrot .

the

a carbon

at ributed t o the oalescn in t h e orwadf direct on, the contra y, the distr bution of t h e opti n t o celrat

y(380 n

also

nucles

the coalesn

prot n

deut rons

a ascde a residual nucleos

and

are explosiv

light

from oxygen

y(580 X

of

of

contribu on

nevig

break-up

the ions

+ MeV)

neutron Fermi

Since

and

sub eq nt

in

emison

.1

Fig. main

+

part

dominates

break-up

at

d

Later

fragments.

Fermi

+ C

of nucles.

The

elihw

of

RHIC,

si

the

X

1.0

3c

-s o

Nw

in

the

part

saw

de- xcita on

Coulmb

spectra

part

KE -Tan shi,

intra ucle

a wol

enrgy

smal

with spectra

produce

the

undergo s

of

compar ble.

Fragment

wol the fast at nearly

the

with

nucles

Becaus are

of

0. 5

a" W c"

<

E

1.0

0.75

0. 5 b

0. 25 0

0.1

0.75 0.5

0.25 n

"0

0.25

0.5

0.75 1

lescn

the et r

cal u tions ac ount

[9]. dashed,

[7]:

.1

and po

both

Deuteron Solid

dot ed

Fermi

=

of

emison

histogram : and

of

90,129

the

the

el ctromagne ic

break-up.

consider

and

in

result dash-dot ed

02

phot absorption

Contribu s

0.75 1

dis oc at n

(GeV/c) pd

of histogram

MeV/c,

mechanis.

0.5

(GeV/c) pd

Figure data

0.25 0

the

intra ucle

on from

rof

respctivly.

contribu

coalesn

carbon.

Points: casde

difernt

values

mechanis

rof

such

KE -Tan shi

cal u tions of

are

ions

coalesn

should

with

coashown

yb

par m-

take

into

96

The

phot absorption

case neutrons ultra elativ stic region, 6 *E = 7 E On the sev ral GeV, main absorption t h e fast particles nucle s is was found TeV beams) for Au The neutron a t the single the multip e important a t RHIC

are

5 7E

whic

side

the

on

suficent i n Ref. the

[4]. fo

multip e

mechanis .

for [4]

mean

MeV,

to

aver g . for

emison

I

W

the the

emison pion

equival nt

ih

fo

phot n

multip c es

(10A

a t SP lOOA

from

large- apid ty

Ir, ,

-1

GeV)

are

due

. .. . . .

a

neutrons

to

the

to

two

spectrum,

and is equal in

GDR hig

208Pb

evn GeV

8. , decay,

det c ors

gold

el ctromagnetic

be

intra uclear f o the or

4.2

shown

may

on

%59

nuclei,

in t h e

neutrons.

remain g (158A

are

heavy

absor phot ns

model or

up

+ chan el orig nati g

design

one

case many

colisn

rof

produce nucles

phot r duction this

In

Nev rth l s ,

difernt

particles

a heavy evapor ti n

the

distributions for

i

01

abundant When

emison

LHC.

n

is very

evapor ting PbPb

neutron RHIC

at

multip c ty

neutron neutron

information

and

most

5 03

leads

other

colisn

the nuclei

scenario

in

used

phot n

7.2

2.

excita ons.

and

Giant

are

ther Thes zero-dg

as umption

is

in The

In colisn

the

en rgy LHC

They

while

lead.

reach s

nucleo s

and

respctivly.

to

the

deposited

multifragmenta ion

beam)

Fig.

with

E-,

when en rgy

and

becom s

this

the

value the

(2.75A+2.75A

fo

Resona c

rel as d

residual

[8].

of

the

in

sA

same

it

value

strongly is a long results calorimet rs

peak d provide

tail

of

208Pb

on

..

* ’ A

-2

01

,

i

-2

i

.’

..

,

, , ,

._ ~

..

5

0

__

.

, , , ,

, , , ,..... I

, , .

.

,.I,

. . -1

51

01

, - _, _ I _ , -

, : ,. - ’ _ _

I--__

02

25 N*

Figure magnetic resp ctively)

2.

RELDIS

predict ons and

Au

CHARGE

.3

studies. an RHIC

dis oc ation

at

CHANGING

CERN important

nuclei

Pb

fo

A and

SP

detail d

LHC

ac el rato point

en rgi s.

nuclei

for

multip c y

RHIC

at

en rgi s

LHC

and

REACTIONS understanding for

cur ently the

extrapolation

distr bu ions

SP

(dashe

lines).

TA fo

sup lie

fragmenta ion

the

neutrons (solid

in

and

dot ed

the

el ctro-

lines,

SP

the fo

fo

en rgi s

hig est theor tical

mechanis

en rgy and

at

av il b e exp rimental

SP

en rgi s

for

heavy result

provides

ion to

91

Partial ions

the separ ted el ctromagne ic the the

contribut ons

break-up

interacting

in

main el ctromagne ic

charge

with the

part

exp rim nt

dis oc at n of

to

targets,

fragmenta ion

charge

bP"’

[lo],

rof

changi

interaction.

VeG

158A

changi various

I

GeV

bPBO*

158A

VeG

’

section

f

b

158A

cros can

particular

cros

IC"

on

due one

each

from

H to Pb,

to

the

esu

section

el ctromagne ic

dis oc at n

er w

5 AZ

(-7

5 ) 1 rof

measur d

RELDIS

and code

in

PbPb

mode. colisn

i7---14

158A

recntly

to

evalu t

GeV

A851

As

nuclear

forces

the

it si howns may be

on

bP-’

VeG

[lo].

bP80’

Althoug

er w

role

in

explain d

not Fig.

of

the yb

3,

bP"*

\A’*

on

102

01

01 01

0 10 1 01

charge

charge

1

Figure

SP .

at

1

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obtained

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fo

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- 05

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region

exist

changi thres old

Pb MeV,

for

A2 in

in

detail d

fo

heavy

fragment

nucle s,

wer

in

strongly this

el ctromagnetic Ref.

the region is uficents = 0 chan el

.1

.3

4. 5. 6. 7.

.8 .9

10. .1

dom-

chan el. wher

[l ], det rmined

understanding

mas e

ions.

fo

and

A variety

fo

multifragmenta ion.

despit

CERN

A.S Kurepin,

author

the

ions, data

predicts

absenc

for

the

1.N kind

very

si

namely

mechanis fo

PbPb charge- n i also

and Giacomel ,

G.

author

A

on

partial

grateful y Iljinov

The

heavy the

SPS

in

model The

fragmenta ion

the

partial

geom trical colisn

inte s the

Mishu t n hospital y

complet

M.

indebted

place

demonstrates

a very

acknowledgs

or

takes coalesn,

Giorg n ,

to

and

overlap fragmenta ion

fruit l

on the

dis ntegra ion

in t h e Fermi fo

the

neutron

nuclear

the

chan els

emison

the Organiz

fina c l

el ctromagnetic break-up,

col ab r tion

subjects Patriz

L.

.P

Ser a

the

dis oc ation col id ng

fo

with

such with

this

and Com it e

densit e .

domina ce in

fo

sup ort.

fo

evaporation,

chan els. A.S

talk.

are

fo

el ctromagnetic

A2

nuclei

Comparison =

Botvina, Discuion

greatly

C.A Bertulani G.Baur, F.Kraus , I.A Pshenic ov, A.S Iljinov, J.P Bondorf, A.S udov, I.A Pshenic ov, K.Bab , H.Dekhis , S.E Hirzebruch,

and

K.Henck ,

G.Baur,

M.Grein I.A Pshenic ov, A.S Botvina, I.Endo,

G. iacomel ,

I.N Mishu tin, A.S Botvina, I.N Mishu tin, H.Fuk ma E.Beck r,

Phys.

D. T r a u t m a n , and G.Sof,

M.Giorg n

et G.Huntrup

J.P Bond rf

N.Bianch

A.S Iljinov

A.S Iljinov,

Rep.

al.,

J.P Bond rf

J . Phys.

Prog.

Nucl. NucLPhys.

92

et

(198 ).

,42G

Part. et

et

et

163,

al.,

al., al.,

et

al., Phys.

Nucl. Nucl.

Phys. et NucLPhys.

Phys.

,4 A

1657

Phys.

al.,

al.,

,45 A

(19 8). Phys.

Rep. Phys. Rev.

Phys.

578

,752

A,

23

39,

Rev.

503

,61 A

Rev. (1986).

C ,15

(19 3). 19 ,

C ,06

13

(19 7). (19 5).

0491 57

2085

C 57,

ap re-

KE -Tan shi

in

print. (19 5).

(19 ).

(19 7). 1920

is

,. . 1 -

-6, J.P.

the

of fison

REF RENCES 2.

pho-

CON LUSION

4.

ultra elativ stic and pos ible with dis oc ation RELDIS

the

(19 8).

with

Bon-

IV.

STRANGENES

PHYSIC

ThisPageIntolyLfBk

ThisPageIntolyLfBk This Page Intentionally Left Blank

Hadron K.

’

and Maruym

02

Nuclear

Elsevir

Kaon

studie ical also polarized kaon

hador nic region the

A

nuclear

The

Probes

sthgir

10

.devr s

nuclei

the

discue

Graduate

in by

phot n

Schol of

thres old

terms

comparing beams

region.

fo rof

amplitudes

a A

through

the

quasifre

the

with

of

The difernt

in

Tohku

the

exp rim ntal

the

(y,K)

Scien,

phot production. model

reactions.

detail.

K+)

I2C(y,

A

Universty,

It

and

data

3He(y,

er w

predict ons. enabls

compared

su

)OK The

eW

to

reactions with cros discu

study

er w

a numersection

the

er w

esu

the

el m ntary

such

as ( y , a hyperon. fundame t l [ l ] They spectroy. In p a r t i c u l a r , and ecayd

of

INTRODUCTION Phot nuclear

(Y,K+) studie now,

The

in

K+)

using

nuclei

reactions

the invest ga on

of

leav

in nucleo-hypr

fre

cros

in

targets,

at pj.ca ukoh t.c liam@ deam

amplitudes.

the

polarized

of

with

the the

The

study

a nucles

theor tical

provides have

ben

K+)

y in nuclear

domina ce the

and

describ

evah

tag ed

phot n el m ntary They

phot n

l iw

are

the

beams.

In

reactions of

to

observatin

beam.

kaon evig

production su

They

si much ben

K+)

of

to

study

are

belivd

behavior the

the

the

the

hador nic

phot n

and

of

exp rim ntal be

amplitudes,

tag in . of

the

of

)OK

we done data

be

a A in

than

any duty

at

in

comple ntary nuclear

(7,K)

the

whic rof

K)

(y,

hadrons, becaus

data and data

K+ notice

set

probes.

producti n to

into study

to

interac o s. hyper-nucls

hgiH 3He(y,

fredom,

the

A phot r duc ions

Finaly, can

amplitudes

longer

importance avilbe.

The

a complet

and using

spin-fl of

nucles-hypro

of

a nucleo

op rtuni y

done

the

not

study first

proces

degr convertig

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extnsivly

spite

12C(y,

the interp ta ions.

be n

dep n t mediu

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ielcun

the

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spin

requi m nts

in and (QF)

(7,

requi d the

with

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used

y beams

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=

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ew

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SPring8.[4]

of

s el

suitable

using study

to

section

article,

Thes

compared

with GeV-rgion

us

S

have

[2]

path

as oci ted

the

,7(

nuclei

this

use

reaction.[3]

enabl s

K)

on

yb thes

A-producing mean

reactions

reactions,

production

(T+,

In

*E-mail:

lA

Jap n

near

phot r duction

,7( on and detailed yb facil ty reaction

De p a r t m e n t ,

phot r ductions cal u tion

beams region.

B.V

Electromagni (Editors)

on

98057,

1.

and hyperon informat be Until the A-hypernucli.

Scien

with

Ohno

Maed"* Physic

a

Physic H.

phot production

K. Sendai

and

near

OK the Laser-El ct on Ph the

poten ial.

measur nt

and

l iw can

near

hig

importance

of

the

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to probe

the

the Since on smal

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can inte s y

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thres old ew

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introduce invest ga d

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(-/,K)

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y

201

TAGX

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EXP RIMENTS

K+

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phot r duc ion

Figure

12C(y,

pared the quasifre

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flight

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with

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0.78

K+)

.1

Diferntial

reaction. the

el m ntary

proces .

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Toky -

Counters wal.

0 to

Figure data compared f o four. as umed. The dot-dashed prot ns contributions. rise more Figure 1.0 - 1. cent r d

at

1. counters

03

fo

GeV/c.

the

eW

slowy

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curves s shel ,

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wer

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terms

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taken two

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show

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the

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fo

at

range

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distribution

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hod sc pe ,

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GeV.

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spectrome r[5]

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Carlo

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ar ow

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fo

result

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er w fo

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distribution

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ev nts

Drift outer-scint l a ion-c u ter

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Figure

out

side. dif er nt al

aver g

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Labor t y.

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particle

on

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charged

Cylindr ca

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estimates

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TAGX

dat [7].

and yield structure

is four two

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shel in t h e region. efctiv in t h e replac d number with Theoretical ces model[ O]. section tions fo the 0.21 cal u ted ure The curve proces mainly of t h e that Another reactions The decay and cal u tion explained 2.2.

through mis ng

integrated

prot n

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is 4.2 distortion. les

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based

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signature

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and experimental eficny.[5]

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for

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]8[

rec ntly

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predict al

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binary

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diagram

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2.

The

The

model.[10]

subthres old nucleos.

The

Monte

Carlo

o =

about

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1.4pb,

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meson

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shown The

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section code

peaking. provide

was

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step

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K’)

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spectromet r. in F i g u r e cel.

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data.

the

sum

in

K+)i2B.

thin-sol d

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value

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is a rapid fo

func-

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production

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prot n

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tif

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step

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=

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nucleo s

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R

behavior

TAGX

efctiv

I2C(y,K+) and

to

must

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gen ral

dominates

the

first

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mas

used use

becom

proces .

in number

the

intra uclear

to

exclusiv

saw

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the

fo

K+A

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the up

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ew

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+-

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from

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The

a number fo to a A, the fectiv ,7( K + ) proces . Our result si a usefl to l t o probe

a thre both

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revo

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changes

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Since

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region

number

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thin-dashed

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The

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be

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oy,~+

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401

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yb using

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cros

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two

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Figure

with model

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KAON

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In

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at

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rof rather

predict ons

si

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producti n

repo ted numerical

to

PHOTOPROCUCTION

A producing

the nucleo

twelv

the section , Laser-El ctron-Ph ton

In It

leading

this must

to

el m ntary thre to

polariz t n

complet

The

spread operation.

denot

4.

with

that simlar

K+

the

phot r duction.

fo condit on, be

phot n

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A

single

kaon

a spin The

phot production, kaon polariz t n

1/2

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phot r duc ion

defin data

asym etri .

are asym etri

a spin eight

proces

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set

rof

yb

amplitudes

predict AS1[4],

POLARIZED

Ther exp rim ntal

values

the

Lines difernt

the behavior

WITH

amplitudes. double

them

Figure 3He(7,K0). mates

The

of

Diferntial

wohs models.

are in

the the

(7,

C4[15]

cros

the

(7,

1 GeV

)OK

PHOTON

obtained

section numerical

K+) and cros

enrgy

from cros ]61[4WA

rof

esti-

section

K+ region.

are are

section

BEAMS

0 noak posible

si p h o t r d u c e on a spin sta es in t h e sy tem. can b e xpresd with four diferntal observal in ( 7 , K ) a r e of P ( r e c o i l ) , C(beam) and T(target), t o measur ighte observal of elmntary N(y, K)A proces. almost 10% polarized phot n with range from 1 . 5 t o 2 . 4 eVG 107/sec hci w is limted yb t h e spectrom l iw be complet d the el m ntary A producing in a n enrgy range of 7 E = 1.5 study the kaon phot r duction

spin -ni

light -

kaon

the

2.4

in on

501

SUMMARY 4.

eW measur d the thres old cros section found that efcts of y, phot r duction (7,K) si eryv wen Laser-B ckw d Compt n informat

region the kaons,

the are

diferntal compared

ac ur te

to

cros 1.3-GeVToky

nuclei.

study

to

numerical of

eW

understand

the

section

with

study

A pro ag ti n on

efctiv

at

the

must

noted

importan

in

interac o

the

the

the

kaon

measur nt near

12C(y,

synchrot

estima es

el m ntary be

that the

facil ty

A-nucles

of

el ctron

K+) and (7,K) rof

phot r duction.

theor ical proces

the

fut re. the

and

and

labor t y.

3He(y,

of

the

They

structure

interp ta ions.

and

fut re

fo

invest ga on

K+) mediu

can

evig

the

reaction 12C(y,

)OK

nuclear

spin

They

l iw

The

observal

be us

A-hypernucli.

of

in eW

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in at

done

important

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and

Bernh im,

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H . Tamur , ther in. .H Toki,

A376

(196) H.Yam z ki,

and Phan 461

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C58

and

0. Rev.

and Richter

B. A.

Sagh i,

Ruber,

Phys. and

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YSato, H . Tanit

a,

T. Iwat

a,

. S Hasegw, (198)

S.Date,

559~

e t al, Ha,

(198)

A547

K.Maed ,

T.Saito, L . Tang,

35.

Physical

M

Priou,

D.

158.

and Nulc.

0

K. ubota,

Xuan

(1976).

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A629,

e t al.

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K.Maed ,

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K. oshin ,

M. 168,

.c97

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G.

H.Park,

K . Tak n shi,

K.Imai, and

(1983) (192)

H.Outa, T. Tam g w , and .c72

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N.Kumag i,

C28, 547

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T.Kish mot ,

K.Omat , (198)

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Hadron

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02

Nuclear and

Elsevir

Physic

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REF RENC S

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Hadron

K.

dna Maruym

20

Nuclear

dna

Elsevir

Physic

.H

Scien

htiw Okuno

B.V

Electromagni (Editors)

sthgir Al

Phenomlgica

resvd. 13

fo

aspect T.

, S. Mart"*

"Jur san bCent r

ration smal , crit al reaction means

Using the

*Sup orted +Sup orted

form

mo ent

Ben holdbt

and

of

pro ag tors

whic nucleo

factors, the

of

contribut ons nucleo,

ew

we

can and the

ext nd

some kaon-hyper

the nucleo

to

nucleo

Indoesia

The

of misng

model

1642,

Physic,

rep oduc

invest ga

the

Haberz t l

Depok

Departmen

ASU the

.H

Indo esia,

Studies,

model

on

no

Georg

exist ng

the

Washingto exp rim ntal

relat d final resonac. higer

Universty, data

phenomlgica

sta es

phot n

to

yB enrgy

the regizn

aspect ,

anom l us

of

kaon the

regim.

INTRODUCTION A

rec ntly theor tical

wealth

of

an In

this

made

isobar question,

chan els

pa er

the

ap ro ch.

be n

isobar p1 ( 710),

precis to

ew

start

in

in

structure

whet r

model. and

open have

whic

form

has part part

,rev woH ned ben

can by

yb

for

such

evig SU

the

pl~(1720)

be

the at

the phenomlgica

signfcat

are

Univers ty DO E

span

dleif

prosed

of from

in semoc

corespndig has resonac,

know

kaon chanels.

avilbe.

devlos r

structure

el m ntary

kaon chiral

the

K’h in

ben decay

widths

coupling

as

el ctromagne ic pertu ba ion recnt Becaus

to

years to al

from constru ed

phot -

gnolA

aspect ,

the

s el

enrgy.

er o -ba s cros know

hci w into al

tif consta .

and

with

hadronic

with

since

phot production most

Res arch grant

as

section.

wen

production

proges

to

the

the

SAPHIR

be includg

relativ y

are This

resonac

and

Kh el m ntary

el ctrop du i n some

theory

can

yb

PHENOM LOGICAL

kaon

demonstra ed unrealist c y

on isopn

model

SOME factors

of

The

the

publicy

can some

data

thre ben

data

to

to

in

made models,

have

AND

it

data

has

weN

found

an lyse

vert x. the

avilbe

discu

MODEL Hadronic

K+)

this

as

par met rs.

THE

hig -sta ic side

their

inter s ing

fre

Previous

wen becom inter s .

of

have

2.

hadronic enrgis, thermo e, (7,

205,

isobar

hadronic

phot r duc ion

Universta

D. C .

an

that 51 ( 6 0), some

2.1.

Nuclear

noak

C. FMIPA,

for

Washingto ,

1.

has the considerabl

Sumowidag",

Fis ka,

phot production i.e magnetic ap ropriate

simple

Probes

suficently

invest ga d

KC data

leads

to

be colab-

ro

to

other

thre

chan els,

a yb

sta es

yb

of

in

the

adjusting

ASPECTS

form

no.

of that

the

large for

DE-FG0295ER407

factors

presnt models predictons Graduate

evah

nevr has

ben whic

include isobarc rof

Education

evig

know

models a odg the (y, (URGE)

a form rof

descript on

)OK grant.

factor diverg

a long chanels

time.

at

higer

[l].

of

at

the -ru’F

the

It

14

l ew know that incorp ating a hadronic form factor helps al eviat this diverg nc and, simultaneo s y, leads t o a problem with gau e invar ce, since not evry diagram in t h e Born terms retains gau e invar ce yb i t ~ e l f . ~ The question f o gau e invar ce actual y one f o the central suei in d y n a m i c l descript ons f o woh phot ns interact with hadronic sy tems. While ther is usaly no problem at the tre-lv with bare, pointlike particles, t h e problem becom s very compli ated once t h e el ctromagnetic interac ion hadronic is consi ten ly incorp ated with n the ful complexity f o a strongly-interac ing sy tem. In the previous work [2] e w aveh studied t h e influec f o hadronic form factors o n kaon production, by multip y ng the holew amplitude with a n overal , mon p le, form factor F(t), i.e

is

?IM wher aver g sup res does contributions One the for may The terms coupling by invar ce invar ce ther fo e translated

the

subscripts efct

the have

not orde

In

al

nucleon,

fo be recip ,

On

the

to

resto most

SU(3)

3Since terms.

fit ing

eht

gau e

widely

have

the

sym etry,

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used

in

in

meson situations

As

shown

Ohta s when

to

and, in

one

some

si due

amounts

contribu ons

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]5[

ap roximat ons.

the

the

alF(s)

t o b e superio f o the data Such couplings form factor terms

kaon

+

Ohta s using

in are

values

can ot

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This

be

fo

and

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to

to

drop ing

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problem yields

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at

violenty

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includes

handle

a3F(u)

for

yb

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the

Ohta s,

the

ac om date

ad it onal data leading

cur ent gau e

to

the

construc

strong-i terac ion

Born

For

the

very large a compreh nsiv a presc ipt on ful complexity our langu e,

In

+

al ew since

2a

found

+

form

x2. fo

for

treatment the

the

couplings

in eht

forme Ohta s discuon

that

the

el ctri

fo

the

gau e gau e

problem

method

this

fo

ac ept d

resto ing

of

and

can

, .1

the constants

terms. factors

since a functio values

as

can

in

Clear y, method

the

el ctri

provide

method wil

due be

close

lim ted

to

fashion

form Symbolica,

=

factor

the suce

hoc

ad

phot production

this

3a

simulate

cur ent

M;Iec.(~,t,u).~(~,t,u)

and

the

ad it onal

terms.

constants

to

fo

this gau e-viol t ng

kaon

f o diverg nc , increas

coupling

contribu on. invari nt,

al

[3].

to canel

terms, spite

In

invar ce,

in

could

put

ne ds

+ +

than el ctri

alre dy

point-l ke.

one

diagr ms

evn

can ot

problem

phot r duction rather

[4], has

a2F(t)

not

solve

ther fo e,

Ref.

Born

are

pro e ly,

cur ent

complet y

problem

Feynma

methods

the

the

foundation.

not

Haberzet l phot production.

=

to

resona c

avoid

(1) ;

to nucleos

~~ [~,t,u,F(s),F(t),F(u)]

t , )u removs

to

el ctri

reso t

as

ref

invar ce

us al

does

hand,

R

that

and

presc ipt on

sup res ion

=

P(s,

Haberzet l descript on predict on. f o a hadronic

beyond

Ohta s

howevr,

not constants.

must

By

microsp

and

fact

as

MB(s,~,u) with method

any

t , )u ] F ( t ) MR(s,

B

the

writ en

do the

fo

diverg nc

the gau e-viol t ng

+

t , )u

[ ,s(BM =

is

be

(3) Haberz t l s

terms. pro sed a reason ble SU(3) to the t o t h e absenc to

the

by

Born

51

Table

1

Numerical

lous column

values

magnetic

(2)

rof

mo ents evalu t d

si

the

yp-+K+R yp-+K+Co +COK -+

Total

The

One

mo ent, years state

wher

of pro e ty

sum

phot n with en rgi s,

the whic

ago the

rule

for

roF

-0.13

0.31

en rgy

To

ther

estimate

=

the

smal . the

0.31, final

K;(K)

is

no

result

850 instead

in

IK~(K)I/K~ contribut ons

and

inter s g fo

Karline s

a positve

Table

VeM

be n

this

avilbe

bound

ro

sta es

cros

data

up er Eqs.(5) shown

An

to have

the

the

cal u te

result

up

cros

consequ

cros

of

and

(6)

of

and

contribut ons, 1.

we

krow

contribut on

and

to the si t h a t [lo].

ELSA

we

polarized

esu

previous

cal u tion

our

the

noelcun

the of

esu

and being

nucleo

its

and

posible are

with O T ~ ,

Our

rof

at

(4)

section for

5 0.14 feature

Eq.

section

3.214

=

and

Hearn,

spectra [6].

Eq.

(5), 3.60

=

:K

anom -

elihw

0.1

-0.25

0.5 -0.19

In

and

the

prosed

yb

combinat s

0.31

si the structure.

0.19

has

anlyzed

krow

wher

rep s nt

TO

yields and

phot n

to

5 0.94

K~(K),

]9[

operato neutron s

the

[7].

yields whic

and

double

This

Using

of

this

whic

phot n

of

magnetic More

that

rule of

ben

ap roxim ted

values

anom l us

a sum lim t

JLab.

real

nn(K)/n, prot n s our cal u tion rof the

from

of

570.

inter al

targe

cor esp nd

el m ntary

square

0.31

rule

beam

data

of

sum

section plan ed

+-

Drel resonac

polarized

y n

fo

nucleos

the with

-+

the

Koh K+CK Co -+

y n

to

si o b t a i n e d

)1( K:

pro e ti s

(GDH)

denot

observal

are

a direct indep tly t o the

sta es

Total

tnemo

state

as

pur ose,

denot s

ground

writ en

Experim nt

Column

Experim ntal y,

0.15

as and

21 0

exp riments

practi l

The K~(K) hyperon with

0.3

si relat d

be

neutron. (6).

final

y n

-0.24

exist

Gerasimov,

OT I

very

and Eq. using

kaon-hyper

0.4

citengam

important

and

spin .

phot n

suolam n

Gerasimov-Drel-Han may

0312

polariz t on Since

to

prot n

yb

-0.63

2.2.

wher

of

of

-0.26

y p

caled

contribu

nucleo

target. polariz t n

with

the

In Eq.

to al

K;(K) swoh

magnetic a egativn si obviusly

at

higer

with

=

that

moent contribu on

2. -0.63

the consi te

the

and

MA I

phot n

(5)

=

then

terms

cros

, , v

03

ground

saw

point,

the

perfomd

than

E

section.

[8].

kaon-

GeV.

and are

of

61

1.7 1.6

1.8

9.1

2.1

0.2

Figure .1 Total tion for KfA tion on the dashed line show without the ona ce, while is o b t a i n e d by 013( 960) state. RIHPAS data noted by t h e old data are open cir les. 2.

prot n.

cros

phot produc-

the

Ol3(196 )

the including

shown

sec-

res-

solid The [12]

solid

The

model

line

the

new

are squares,

de-

by

the

W (GeV) 2.3

A brief

Investiga on

inspection

nucleo resona ces studies have sug e t d chan els, such as cros section data time a structure this structure. As section. Although a ewn resona ce, becaus f o pos ible production thresholds whic can al l e a d Her , e w lim t ourselv the mis ng o r po rly The consti uent around 190 MeV. K A decay width eW have perfo med mas , width and reproduce the structure &(1960) state model prediction without this resona ce the new resona ce SAPHIR with the new for t h e dif er ntial Ther fore, e w would light on t h e contribution

are the around

fo to

misng

the

observ d that

KA for [12]

W

shown

a structure the en rgy broad, nearby, t o structure

Howevr,

=

in

p(7, 190

Fig.

such

only model

to resona ces. only

K+)A ,1

in

region in

"mis ng

KC

the

the fo

our

to al

bo k

Nr7 chan els

MeV.

previous around

as pos ib l ty

Capstick a wef the Sl1( 945), f o thes

rev als +

fits

for

the

cros

section 190

resona ces, phot production K+h

fo

resona c [l ].

chan el, Using

cros

shown

MeV

and Pl1( 975),

fo

structure be n

sta es,

eW

W

one ef ects this phot production.

slight y

The

peak

near the

observa l

are

to

result two

below found

the

,1

reproduce

model

not

K*A,

final-st e

and

fo new

indicate

the the threshold, cal u tions

sign, is

the

and that

in

i s l ew

final due

to

have

tif

x2,

al

while

suited

ad it onal interaction.

imply

not

013( 960) to

to

four

det rmine

in

Fig. in

is much to

asym etry.

ac ordance

cros only

fo sta es

sta es.

the inclus o

for 1,

can quark wher

the the of

smal er shed

first

one

sta es

only

total

sta es,

new a sign f ca t

but

betw n

phot n

many

other

the

investiga e total

are

fact

MeV, the

for

the

KA*

model

to

ew

shown

190

predict

RIHPAS

im ediately a chal eng ther

predicts

[l ]

the Quark

strongly

is in

found

reducing

up

cal u ted p13(950),

al owing

Fig.

becaus

q’, through

40% couple

does

rep s nt

also

this

Roberts

isobar

can ot

but

while [13].

in

cur ent

than

experiments.

may

data

section

have

les

Inter s ingly,

model

that

them

that

scat ering

Nr7

are each pos ible coupling constants fo the resona ce. 901 MeV, a t W around a rema k ble agre ment, ew found and our extracted result the model show only leads t o a second peak at data. The iferncd betw n cros sections. The largest sug e t that measuring of t h i s state i n kaon

[l ].

Thes

the

and

data in

those

overlap ing

know

quark

resona c

particle

more

71 3.0 2.5 2.0 1.5

o. 1

0.5 0. 2.5

a^ v

2.0 3.

1.5 ~

0

9

kaon

0.1

0.5 0.

2.0 1.5

1 .0 0.5 0.

1.6

1.7

1.9

1.8

EXTENSION

form cros

as

Extendi g demande

the increas

are

section

the igher-lyn D G H integral, be d e m a n d e . In Ref. are respon ibl pro ag tor regizaton invest ga gniwol F

model

yb starts

the

[14]

it should her

the Ref.

of

only

the

to

sup re

monticaly model

model [15].

be

the

be n used the

ew

but

K

OK nwohs

Total dashe withou

line

and rof

production

prelim na y

cros

with

hadronic

si

K*

roF

obtained

pro ag tors

K+

the

line

data data

[14].

section

on

swoh yb

The

regizn

is

old

(solid

-caf

in

as

(open

for pro-

the

form

regizaton. phot r duction,

the

in cirles)

-osi

the Fig.

,1

cirles)

2.

EN RGIES

to

isobar has

for

data.

to

nucleo

an

rapidly

unable

2.1

HIGHER

TO terms factors

2.0

The model

2.

phot r duction

(GeV) W

Born

ton. bar tors,

solid the model. nota i n for and are

2.5

3.

Figure

Especialy

higer a functio

as

resonac

enrgy the ro

whic shown

divergnc qualit ve multip y

is considerably

in

that instead the

of

the increas

to also

of

the efcts

Feynma

cros

of

enrgy. case acount

the the

section of

at

contribu s

this

section,

us al of

requi s

As

proely cros

compli ated

regim

using

pro ag t s

rof

K C+ rof

point. higer

krow

shown production,

eg R

the ,rev woH

at higer thus

Feynma

a no -triv al in Fig. enrgy

and

enrgis

phot n

from the

ind cat g

pro ag tor. pro ag t s

the

above

-

si stil

mi*)

to

the

hadronic

2 GeV

predict explor

enrgis

While in

since

the

the

t-chan el

study l/(t

task,

2 , nev region wher in orde contribu ons

would resonac

that

of

the

underway, the

the model.

a pro e K*(892)

to

the

eg R ew

18

and ind cates the

Kl(1270) form

wher to behavior Reg

of

yield

the

a(t)

the

Fig.2,

This t-chan el data any tif

=

Feynma

The

Reg

ew

can ot further

and

for

the

be

resona c con lusi

investiga e

propag tor amplitude. is t h e n

a’t

the

denot s

sup res

can model

the

to

withou

is les

chan el

to

fo

se m

K C+

the

the

strongly

achiev d

operator given

in

refit d

compare

explan tion

propag tors

in

propag tor

+

0a

the

fo

model wher propag tors a bet er

resona c Reg

be

cor espondi g lim t

the

give

reg izat on,

contr l ab e shown

in

in

drawn.

the

this

more

flexibty yb

Fig.

the

t

transit on

In

en rgy

the

mg.,

thus

regim.

in

since

hadronic

rep oducing

prelim na y l iw

ew betw n

the

include

and

at

hig For

wher

the

reg izat on.

en rgi s

the

hig form

m$.), -

(7)

data

withou

(t

intermediate

Equation

ap roximat ng

and

section

stil

of . e g e R P the ’K For

trajectory.

with cros

2 are fut re

a factor

+-

phot r duction

model at

[15].

of

kaon

isobar

data

with Ref. in

en rgy

factors.

[16], the

mediu

K Cf

hig

and

clear y the is

cros

ew

have hig

and,

proces ,

t o wait

en rgy

en rgy

en rgy

shown Obviously,

in

ther fore,

section

behavior

Howevr,

has it

reduc s

wol

result

the

PRegge

state

since data

the

use

data. fo both befor regions.

the

in

the

REF NCES

T. C.

.1

2.

4.

’N

K.

3.

H.

5. 6. 7.

Mart, Ben hold,

.B.S

H. Se

8. 9.

10. .1 12. 13. 14. 15. 16.

S.D.

C.

Physic ,

Ohta, Haberzet l, Haberzet l,

W.

T.

for

F.X and M. By 46

Seat le,

Phys. Gerasimov, Drel

R.L Workman D. Drechsl, H.-W. Ham er, S . Sumowidag o I. K a r l i n e r , S. Capstick SAPHIR

Ben hold,

T.

Mart, Rev.

C.

Phys. Mey r,

and

A.C thes Prog.

USA, Ben hold,

C 04 Rev.

Sov. and

and and

Hearn, Part.

R.A

(198 )

C.E Hyde-Wright, D. Kusno 196 (World

T. C 56

J . Nucl.

proce dings.

Phys. Nucl.

Arndt,

Mart, (19 7)

Phys.

in sgnide corP Scient f , 135.

and Rev.

Phys.

Phys.

Phys.

2 (196 )

43

T. 2041.

16

nucl-th/97018;

430;

CEBAF/INT

(19 5)

R1074.

19 7),

Workshop

p.16

C 58

Rev.

(19 2)

18 ;

on

(19 8)

R40.

1789. 0281.

Let . and that

51

908.

(19) (19 8)

(20 )

the

(196)

06

85

C

Phys.

D 54

(19 5)

D. Drechsl, and T. Mart, and T. M a r t , Phys. Rev. C Phys. Rev. D 7 (1973) 71.2 and W. Roberts, Phys. Rev. D Col ab r tion: .Q M Tran e t al., P h y s . Mart and C . Ben hold, Phys. Rev. C 61 Le , T. M a r t , C . Ben hold, H. H a b e r z e t l , ref nc s ther in. Guidal, J.M. Laget, and M. Vanderha g en, the time f o finshg this pa er e w realiz d the y p + K C+ chan el has be n published (19 ) 31.

+

Feust r,

Let . Rev.

fo

Singapore,

Rev.

0741. B 45

012 (R).

(19 8)

L.E

Nucl. in:

the

20.

Phys.

Wright,

S.

final

A

nucl-th/9071

Goers

version

627

(19 7)

e t al.,

fo

Phys.

SAPHIR

645. Let .

data

B

Hadron

K.

and Maruym

02

Nuclear

dna

Elsevir

Scien

Hyperon

K. fo

Rida -cho,

Jur san,

Nuclear

sthgir

resvd.

eW

an lyze

70 ,

tion natural mation d(e,e K+)YN data

+

y

found

N

4

near

Kaon

phot production

Physic ,

reaction

Okay m

Univers ty

K+

+

,1

+ y

proces.

K+AN

fo

d

and

Georg

+

+

A(E) and

Signfcat

a rec ntly

K+EN

and

Washingto

Universty,

Bochum,

K+ NSC89

and

Indo esia

The

Ruhr-Univers ta

+-

Haberzet l

1642,

Physc ,

deuteron

Scien,

Depok fo

the

, H.

Ben hold

Indo esia,

Physik

f79CSN A(E) the

C.

b,

De p a r t m e n t

Germany the

from

Mart

Japan

Studies. 205

both

T.

Univers ta

Theor tische

interactions

19

a,

Ap lied

Okay m

D. C .

fur Bochum,

N

using efcts

thres old .

fo

updated

the

Nijmegn

YN

the

soft

production

core

final

operator

state

hyperonfor

interac ion

INTRODUCTION

.1

for

Al

Probes

FMIPA,

for

dInsti ut D-4780

the AN wil

Electromagni

Miyagw

Fis ka,

Cent r Washington,

poles

B.V

(Editors)

in

Yam ura , Glocke

De p a r t m e n t

nucleo the are

with

polarization

H. W. 1-1

Physic H. onukO

Since

hyperon- ucleon

proces fo for

Rec ntly,

In

strength elastic have

OK

such

candi ates

the

d(y.

ew

around

this

0 =

visble pa er,

total

K+Y)N and

the

y

as that interaction

YN exp riment found

AN

ew

and

efcts predict

cros

and property

the study

alow

+

scat ering

are that

d

being

various

CN section .

in various

the

by

has

such

exp riments

K+

t-

exploring alre dy

Y

the

an lyzing

be n

an lyzed

+ N

the in

meson-th r ical

thresholds[l]. of t h e The production inclusve

+

Hal

YN

and

are interac ion.

cor elat d

perfo med

-

d(y,

observa l

+ d

e -+

Y N near

pole

to

+

perfo m, One

YN

in B.

The

AN hope

difcult e

Hal

interac ions

the

CN coupling and cause is t h a t the pole structure proces mentio above. K+)YN and exclusiv includ g polariz t on

K+ final

+

can

sta es.

at C

EN

thres old

d(y,

hyperon

Y

+

obtain

N An

TJNAF, gen rate

enha cem nts of

while

as

inforinclusve

the

t matrix

YN

K+Y)N

produc-

S-matrix

is relat d the

observa l .

ap ear the

in

the

proces

FORMALISM

2.

The

reaction

proces

y

+ d

-+

K+

+

A(C)

+ N

are

expr s d

by

the

operator

iT

as

to

120 (b)

6-

K+Z N

., 700

Figure

0

.1

and

indicated wher repres nts

Inclusive

the

by

the

[a].

operator

The

repres nted

wher interaction can

phot n

operator

is de uce

800

the

d(y, lab

ar ows.

the

with the

YN coupled

the

interaction

cros

section

7E result =

state

cor espond

nucleo

[MeVlc]

The describ

Uij

as

K+)

en rgy

tyi

deuteron

PK

set

09

fo

hyperon

integral

eW solve this set ( 3 ) after parti l-wave el mentary proces y +p K + + A(Co) in t h e driv ng term in E q . ( 3 ) . Equation the resulting amplitudes are transformed C-p yb whic the inclus ve d(y, K+), polarizations are calculated. roF details,

as

GeV.

around el m ntary

to

including

and

1.3

the whic

2 1000

is

a function The the

AN

and

--f

exclusiv

YN

-

decomp sit on (3)

CN

the

y

rof

+

si solved

into

ew

by final

in

equations

K+CN

those

state

coupling.

final

K+

+-

on

d(y, the

ref

Nijmeg n

read

in on

the

K+Y)

iso p n

+

pK+

KiAN

N

are

interaction

mo entum C-

eW

ignore

are particle to

cros

ref.[3]

base

39

for

and

enlarged

K+ A(C), +

From

890

08

mo entum

y+

the

870

[MeV/c]

sta es.

Ti,

n

PK

f o lab thres old threshold two

proces

gen rated

the

068 850

the

Eqs.(l)

base

sections

AN

and

and

(2),

is

meson

one

thre

EN, Con

An,

and

=

>

j,Ql

The

incorporated

are

(b).

Ki

and

space.

pro e ly

in

and interaction

NN

proces ,

&+,lab

K+CN

but and

hyperon

RESULT

3.

(OK+

At

pres nt: =

0 ).

ew The

cal u te

Nijmeg n

the

soft-c re

observa l

YN

only

interac ions

for

the

K+ NSC97f[4]

meson

scat er d and

NSC89[5]

to

0 degr

and a

12

rec ntly used.

updated

production

Figure l(a) K’An, K+Con the SC97fN and of t h e p l a n e wave K’AN ( p ~= The two pron u ced proces fo A mo entum in and K+CN thresholds. threshold. Around the enhancem nts

show

and

97 .30 the

and

NSC89

operator[6]

K+C-p

the

inclus ve

YN

impulse

MeV/c) laboratory the

the

K+CN

one The

cros

cros

sta es.

interactions,

ap roximation

peaks

wher

C,

by

final

rof

(PWIA).

K+CN

and around

fo

sy tem.

pK

the

and

=

(pK

is increasd a s shown NSC89

whic solid

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the

REF NCES .1 2. 3.

4. 5. 6.

7.

K. V. C49 H.

Miyag w , G.

(19 4)

J . Stoks, 2950.

H.

R.

Yam ura,

A.

M.

Klomp,

Phys.

C.

Rev.

.P

C60

F.

T. M a r t , Yam ura, K . Miyag w , (19 ) 014 ; nucl-th/9 07 2 . Th. A. R i j k e n , V. G . J . S t o k s , and Y . Yam ot , .P M . M . M a e s n , Th. A . Rijken, and J. C . Ben hold, T. Mart, A . Waluyo, H. Mosel, in Procedings f o the Workshop 19 8, edited yb 0. B e n h a r , A . Fabrocin , 19 ): p . 149; nucl-th/9 01 6 . C . Ben hold, T. M a r t , and D. Kusno, in no N * Physics, Seat le, USA, 19 6, edit Scient f , Singapore,19 7), p.16

(19 )

Terh g n,

C.

0243;

nucl-th/9 04 2. J . J . de

and

Ben hold,

J . de

Haberzet l, o n Electron-Nucleus and

Procedings

by

W. Phys.

Swart: R. T.-S.

Glocke, Rev.

Phys.

G.

Pen er,

fo

eL

the

Phys. Phys.

Rev.

C59

Scat ering,

Schiav l H.

Swart,

CEBAF/INT and

T.

C40

(19 ) Feuster,

(Ediz on

W.

Roberts

Rev. Rev.

C61

21.

(198 )

,ablE

and

26.

ETS,

Worksh p

(World

Italy,

U. Pisa,

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Hadron

K.

’

dna Maruym

02

Nuclear

dna

Elsevir

Physic

Scien

B.V

Electromagni (Editors)

lA

Probes

sthgir

resvd.

521

strange s

producti n

ELSA

at

Paul Physikalce

Insti ut,

[l] Bon .

As ociated

with

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strange

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Bon ,

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models.

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Physic

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They

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126

orde s quark this what Lagr n ia pion the new chiral

fo within

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magnitude

phot production questions

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part

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Figure

7. Comparisn

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132

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8.

Figure 5.3

any

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thin

lines

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since ext nsio

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data, when

polariz t ns

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would

prot ns. models

of

measur nt

hyperons

multichan e

be

they

to

could

are

car y

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dynamics

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s el formed.

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out

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Studies precis

on data

chiral

at

sym etry

threshold

with

are

kaons

wanted.

and

hyperons

are

at

the

begin .

More

OUTLO K

7.

The

an lyse tistical kaon

The

in exp riment

pres nt and 19.

wil

and

sy tematic

hyperon

SAPHIR

evalu tion

provide

at

lev.

sta es,

exp riment

Beyond

comprise

hig er

are

SAPHIR

Jef rson

6% precison fin shed

the

Lab,

weN

result

exp cted.

data

strange

and

fo for

later

also

from

the

the

SAPHIR

thre

other

taking

particle

at

on

reactions,

and

prog am

Spring8

data

consider

the in

Osak

det ctor wil

be

tape.

reactions in

The

at

particular has

conti ued

and

be n

at

forthc ming

both

sta-

excit d

dismounted

yb

MA I

the

with the C in

Mainz.

CLAS

REF NCES

3.

The K.H zela3, H. F.W. ’Physikal c e Univers ta Washingto W.J. M.Q

5.

se

1.

2. 4.

6. 7.

10. .1

12. 13. 14.

S. 379.

S.

AB H M

SAPHIR-Col aboration: Glander’,

R.

van

Wieland’,

Lawl’,

Pe 2,

R. Bon ,

Schwile Goers

Tran

e.g

Goers,

E.

et

et BN-IR90

8.

H.

9.

C . Ben hold USA, 19 6, C . Ben hold Italy 19 8, T.A. De G r a n d (198 ) 2419; 403. Y. Yam ot 10 (19 ) 19. N . Kaiser, com unicat on S . Stein ger

2041.

S. Goers’,

Haberzet l

Univers ty,

P10tzke2,

J . Wifkrchen’ Institut, et al.,

al., Paul,

Col.

al., Phys.

Ediz one

Link2,

(R.

Erbe

al.,

et

al.,

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Phys.

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et

615;

T.

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W.

C

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Kitsukaw ,

Weis,

M.

fur Strahlen4Dept. (19 4)

20.

fo

p.

on 149

Project,

SIF 18 .

40 R

Rev.

6 1(e); Phys.

Electron-Nu le

and

T.A. 98 Toky

and

Kernphysik, The

KO-

Paul’,

Georg

p.

56

(19 7)

Physic ,

Seat le,

Scat ering, Phys. Metrop litan

(19 7)

C

N"

nucl-th/9 01 6 . D23 (198) Degrand,

(197)

19 3,

Rev.

95;

K.-I

A612 B391

B.

Bol gna,

Phys. on

Phys. Let

E. Wieg rs’,

und

Physic ,

Ernst2, A.

470.

ELFE (196 )

J.

Braun’, E. Klempt2, Ostrick’,

J . Smyrski3,

21nsti u

Rev. (198)

Nucl. Phys.

W. Klein’,

Worksh p

Worksh p

19 ,

Theor.

31.

The Bon .

(1985) and

Kaiser.

4,

34

Ben hold4,

Jopen’,

CEBAF/INT

16 .

the

D31

Prog.

and

the

Phys.

A

(198)

(19 )

.loV Thesi ,

Krakow,

DC

Meth.

al.),

C.

N. W.

Bon ,

B45 B46

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al.,

U.-G

Instr.

Let .

Let .

W.J.

Universty,

Washingto

Nucl.

Phys.

Barth’,

D. Menz l, I. Schulday’,

Univers ta

Jagel onia

Conf.

et Singapore

J.

J.

Han p el’,

J.

46.

(19 7)

12 7;

Rev.

Elba,

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Kubo

Rev. D38

297

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et and

D24

(198 ) al., preprint,

ib d. private

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02

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Retrospect

AN through

SK

pres nt d, tracted. at J l a b thes

Physic ,

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A hypernucla

fo

KE

and

variety

is discue 12

wher

K+)

precison

hig

is d e s c r i b e d ,

Toh ku

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GeV resoluti n

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spectro y

ref ing

PS.

information

to .

dev lopment.

Universty, t oh ku.

phys.

using

yreV

rec nt

a large

rec nt

reaction

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hypernuclear a to l

as

on pros ect

result

spectro y

875 -0 9

Sendai p

to

spectro i

physic

invest ga

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the

of

fo

data, hig

hypernucl a

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in

dep n t

hypernucl a

by

the physic

whic

AN

(e, ’K+)

S=-1

the

A hypernucl a

regim have

resoluti n

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be n spectromet r

spectro y is discu e

was

structure

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reaction

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(

is also b e x-e

underway

based

on

INTRODUCTION

.1

signfcae towards

prog es the

) at

Al

seborP

pros ect

fo

Wide

interaction

citengamor c lE (Editors)

a

has imot

Rec nt

body

B.V

Hashimot

aDepartment E-mail:

nuclei

htiw Okuno

and

Osamu

viewd.

sci yhP

H.

The

sy tem

A hypernucl i invol g thes

with fo

Ther are sev ral lights on s t r a n g e s f o fre dom with Being ref from sta es. It is also t h e fundamental baryon or n o t . thems lv with a nucleo and nucleo interaction. through hypernuclear uniq e features AN --+ NN, is involes large in heavi r A cen r i g its

strange s

the

A hypernuclear

studies

Pauli [l]

mo entum hypernucl i.

one decay

in

pointed Secondly,

a quanti ative quark, out whet r

new Thirdly, fo

1-

strange s

exclusion

the a hyperon compared

uniq e

aspects nuclear

a strange

question

provide

kaew the widths

degr

spectro y that physic .

and

hypernucl a

that

princ le,

i t behav s

op ortunit es new

fo

aspect

in fre dom.

and

.yaw Firstly,

invest ga on a A hyperon uniq e structures quantum number, has ewn char te is c eakw interac ion ecay.d The kaew with those in fre best place t o study transfer and is domina t Rec nt data on and i t is under

a hyperon

diferntly

invest ga on

decay

from

In no mes ic

revo

prog es

many-bod

of

a nucle s

since

from

mediu

a A

particular, the invest ga on

car ies

nucleos a probe

be

difernt

nuclear

strong new

ins de

baryon-baryon inte s v

the Recnt

A hypernucl a

hadronic

strange s , in

can

invest ga on

plays

a hyperon of

de p of

the

fo

established since

space.

the

mesonic

hyperon kaew kaew

and

kaew exp rimental yek

fo

hadronic demonstrated

many-

interaction pathw ys

the

in

roles i n shed ing a strange s degr in a nuclear sy tem. t o study de ply bound structure may answer keps i t s ident y as a sy tem wil manifest the interac ion betw n those f o the nucleocan b e l ew investiga ed in a nucles show no mes ic weak decay, interac ion in uclei.n It A + NT, weak decay, decay pose a puz le both exp rimental y

138

and dev lopment cal ed the The

K-

theor tical y, It can

be as

nucleo beams

said

emulsion

case

second

investiga on orbit split ings t h e first and mid 0s8 at but i t to k 80s until a key role decay fo A Furthermore, spectros py fo subject

at

BNL sometime

now, in

that

since

the

through

stage

CERN

that

began

and

hypernucl i and

new pres nt

the

wil

when

the

was

in

early

so n

hypernucl i the

A is

experimental

schematic l y us al y sta es and

later reviwd (T+,

new

exp rimental

hypernuclear

being

el ctromagnetic pa er.

s 07 the

the

the

at

)+K

of

,-K( reaction

BNL.

counter

smal er

production

spectromet r with

rec ntly

reaction

the in

.3591

The fo

becam bet er

yb

depth became

thre

first

is a b o u t

A hypernuclei.

light

for

stages

stage

pos ible

the

may

be 213

much i n whic

shown large by

emit ing

state a A hyperon

than

in

is formed

Fig.1

those

in t h e a 208Pb for a p r o t n above Howevr,

rof

si b o u n d

nucleo s.

reaction target

(SK )

strange s .

the the

or

as

p-shel

as

an

a neutron.

a nucleo -h example, orbital

spreading

x

wor aN

,B

2 0 7 ~ ~ 1

Weak

_ . - -_ -

neutro

bPA702

I, I,

decay nomes nic mesonic

.1

A hypernuclear

sta es

and

their

a wef <

A bind g

Ther fo e, are

widths

decay

modes.

gnidaerps

fo fo

with

hypernuclear

I t was claimed that the spinthe nucleo case. Prog es fo The third stage started in A hypernuclear bound states, ful y av il b e. Since late at K E K 12GeV P S played the (T+,K+) reaction. Weak quality than evr obtained. such a s hypernuclear y-ra Thes wil b e also the

fo

neutro

Figure

pa er.

undergon

used

than

far dev lop , fo

pres nt

A potential en rgi s

exp riments

literatures.[2] po ulate

to

in

the

reaction.

T-)

facil t es

alre dy

bind g

The

much

spectros py

has

that

the

in various

kaon are

detail

hypernucle s

when

are

studied

to ls

into

investiga on

SPECTROSC PY

A A hypernuclear

decay

it was

measur ments

was

also

go fo established

mostly

A HYPERNUCLEAR

2.

not

discovery

befor

superconducting

also

ew

stages

util z ng exploring

A hypernuclear first

era ,

time pshel

in

second

the

though

01

Vek

shtdiw

mostly

such

A-particle the nucleo

hypernuclear hig -ly n

en rgi s

state. unbound

are states

As

139

are emis on the Eventual y, states later. en rgy.

calculated

to

thresholds,

hypernucle s that Reaction

emit

be

nar owe

whic

de xcites A hypernucle s y-rays, spectros py

the

is

than below

precis on

and often the wher

+

THE ET R

3.

+

The

later smal

spectros py about the

to

heavi r cros

cros

2 orde s

undergo s

section

the

be

keV

to

particle

case

emis on

weak

spectros py

ap lied

the

to

ev n

fo

decays al

the

they

can

be sta es

by

the

+

fo

are

K+)

(T+,

magnitude fo

both

at l ew

the

from

are

an threshold,

excit d

ordinary its

car ied

nucle s.[3,4]

ground

rega dl s

above

out

a s ilw fo by

el m ntary

compensat d

BNL

reaction smal er

and

10 -7[.KE

was than proces

yb

first those

hig

reach s

inte si y

by

ap lied The

the

to (K-,

a maximu .

Such

AN

VAN(?-) refing

can integrals

fo

reason bly

be

interaction,

fo

C(a,

-fe as,

the

wer

hypernuclear

asre-

reliab e

antisym-

on

backw rd

Hypernuclear

start-

the to

perfo med

and

and

in

fo

=

interaction

information

procedur

structure char -

cal u tion,

functio s

those

of

interaction

exp cted

spectros py

the

tensor interI t is one f o the most i t is n o t easy to experiments. ac um lated prothes theoretical

SKS

SPECTROM-

a carbon T-)

pion

pres nc

the

A hypernuclear

hardly

THE

hypernuclear

the

When place.

For described excita ion

be

the

fo

nucleo take

state.

the

+

AND

the

y decays

the spreading widths, perturbation is m o d e l a t e becaus f o the weakn s Ther fo e, information on A hypernuclear rather straightforwa dly. Thus, AN interaction. for the investiga on fo the realiz d i n A hypernucl i and are and E hypernucl i. In this rega ds, the in t h e strange s nuclear physic . are constructed through G-matrix interactions in fre space. Analytical in t h e form f o thre range gaus i n, si also pos ible t o expr s the fectiv VA(T)L . OA VN(T)L . CTN VTSAN, without f o the radial dep ndent potentials A hypernuclei, thes For the p-shel ]6[.T Wide variety as A , S A , S N and split ings due to the spin-dep n t then calculated. Thes cal u tions are s i much weakr than the N interaction not b e consider . Ther fo e. once the exp rimental y, ew can trace the and ef ctive hyperon- ucl interac ions. compared and the spin- , spin-orbit and a nucleo a r e readily investiga ed. investiga on, particular y becaus interaction through hyperon scat ering spectros pic data whic wer rec ntly the An’ interaction, being combined with

SPECTROSC PY

ones sectio

-/ray

10

fo

REACTION

K+)

(T’,

contrast

wil

In ad it on t o the nar ownes a A hyperon in t h e nuclear sy tem a nucleo and a A hyperon. betw n AN interaction can b e related t o the spectros py is ind spen able teristics are quite uniq e features other hypernuclei such as C hypernuclei is in a uniq e posit n The YN, Y efctiv interactions ing from phenom logical fectiv potentials can b e given b,k, cZk;)ezp(-r2/bT.[5] It NAV = V(T) ATC) (,V ON el mentary interaction. Integration with ap ropriate wave functio s. sumed t o be constant and designated properties, such a s lev structures, action cros sections etc. are AN interaction partly because the metrization with nucleo s ne d hypernuclear structure are obtained and can investiga e the fre spectros pic data are directly action betw n a A hyperon important aspect f o A hypernuclear directly study the hyperon- ucleon For thes studies, hig quality vide valu b e information on ef orts.

+

in

a wef

beams

reaction.

cros The

target

at

sections reaction

1.06

Howevr,

at

BNL, GeV/c

are has

+

A

041

Table Hypernuclear 1

physic E140a

(Hashimot , (Kishimot ,

fOuta.

a n advantage and si s u t a b l e advantage kaon spectromet r(SK ) The SK a covers (T+, the t o perfo m y ray and using the 1. Table reaction interaction The E140a, a A hyperon f o a A hyperon de uced f o a A hyperon wer obtained whic was a s listed yield rate 10 izC per day. #3, ’) wer #4)(Fig.2).

fo

the

spectros py

SK

Among

reaction.[9]

solid

from

bound

In

ground

fo

for Table the observ d

i2C The

fo

the

sta es

#1

measur ment

fo

bound

10

in

the

ev n

out with 1 wer fi"C ground spectrum

A hypernucl i

to

igY

the

the

excita ion

persi t

has

as and

four

to a wide en rgy

the

in

#4

range heavy

most

upgrade state

observ d first

fo

reported

fo peaks

car ied

the

fo

spectra.

out

fo nuclei.[ O]

rec nt

rof KE

studied

hig

E369

hypernuclei,

about

with

SK

a lg/cm2 E36 yb E140a are orig nated

due

sta es. 12

1.5-2MeV

about fo

such

exp riments,

nuclei

is

KE

exp riments and

fo

fo

heavy

at

hypernuclear

in

l ew

hig -qual ty

Much experiment.[l6] spectromet r,

5 ev nts/g cm2/1O9 experiment, near

60

the for

study

the

large an

i2C

past

up

to that

ones.

to

investiga e

iQY,

from

the

configurations

two

two

In

by promine t

and

also they

wer

binding

the pions,

are

is

the nature

SK peaks

A

hypernucl i

that

spectromet r

peaks(#2 &pv

exp riment

for

the

in

of wer

nature

resoluti n

is,

in

AN

en rgi s

io8Pb

noted

fo

listed

and

and

us

decay

hypernuclei

and

ful

yield alows

the

E3 6 It

weak

fo

single-particle p-shel

transfer

take

simultaneously

The

sta istics

the satel ite

and

E419

structure data. i3’La

the the

spectra. target

and

to

a superconducting ground-sta e

f o hypernuclear investiga on years E369

20

mo entum

inte sion

PS.[1 , 2]

improved

thick

in

its

spectromet r

the

rev al d

to With

MHWF % fo

SK

E3 6, A hypernuclear spectros pic inte d a s light

quality

I t was

spectro y, GeV

as

E140a,

as

19

winter

sta es

bound

ac epting

ac eptance

be n experiments, seri

the

investiga ed are

has

resoluti n

fal -winter

reaction fo eH:

the

exp riments

seri

~ 7 1

decay

msr,

large

~ 4 1 151

(T-,K+)

the

for go d

A hypernucl i

iLi

spin- tre ch d constructed

A

them, first

the car ied

fo The

coin de

the

de ply

reaction was

angle

spectromet r

through

in

by weak

Kf)

[13]

16I[ fo

hypernuclear

eH: fo

igY

spectrosc py

excit

po ulate (T+,

spectromet r eficnt spectro y.

favor bly

to

spectrosc py i60

i3C,

10 ,9[

polarized widths

- heavy

i2C,

Nonmes ic

to

fo decay

hypern uclei C

KEKI

large K+)

A hypernuclear

A hypernucl i io8Pb

fo

,aL93,j!

weak

fo

y ray

KEK)

E490

:Be,

spectrome r

decay

and medium

Spectrosc py

Toh ku) E438

(Noumi,

iLi,

KEK) E419

(Tamura,

and

SK

:gY,

weak Lifet m s light Light

Toh ku) E369

(Nag e,

the

spectrosc py

i6Sz:

Nonmes ic

Seoul)

E36

fi"C,

,I ’;

Osak ) E307

(Hashimot ,

with Systematic

Toh ku) E278

(Bhang,

exp riments

that

the

about and and

(#1 @

As1/2

14

and 2$pu @ Ap1/2,3p, respctivly. and wer interp et d a s orig nated the C" core. Althoug thes core nuclei in t h e eakw coupling is considerably greater than discu e that the deviat on spininteraction. 9][ Althoug t o theor tical interp eta ion "C(4.8 Asx)VeM only t o a simple intersh l configuration mix ng. the A hypernucle s is requi d.

enrgy Excitaon

from

excita on the and

fo

cor esp ndi g

The

lim t,

the

the

enrgis

satel i an

peaks

are

excita on

core

excita on

i t si qualit vely ther are configurat 19,20][ Furthe

car y

A hyperon

2/1s

so,

fo car ies

the

that could

but

invest ga on

en rgy

excita on enrgis

arguments

exp cted

about

coupled

data

the

the

en rgy

information

peak

have

]VeM[

to

on

new

2.5

5.0

7.5

a,,

close

oferd

to

peak,

8.4 of

excita on

those on

fo

the

MeV,

I t was

the

problem

from

mode

P,=1.06

0.

fo

6.9

necsarily

contribution

section

sta es

MeV.

seriou

is not

some

cros

excit d

#3

10.012.515.0

be.]

1/ 0

Kt)",C

"C(nt,

0.0

be

to

AN due

of

c/VeG

2.5

5.0

2.5

5.0

7.5

h b k.1

10.012.515.0

Prelimnay C

2 5

0.

Figure with previous

the

.2

SK E140a

High

spectromet r

sta istics

excita on

exp riment.

The hig -quality excita on spectra DWIA cal u tion agre m nt was observ d i n predict ng the absolute The i2C spectrum the excita ion functio A part f o the result fo s p e c t r a by t h e ,-K( A hypernuclear evl

yb

in

angul r

2 degr Itonag

spectrum

sy tem.

distr bu ions

bins

The

spectrum

and

are

er w

si compared with it liw imply that rosc section yb t h e a go d exampl demonstrates f o the other A hypernucl i ilw b e found in ref.[15] Her , T-) and (T+, )+K reactions structure, since they po ulate and

of

5.0

i2C

has

rof also

the

the

fo

first

)+K

(T+,

in reaction.

(T+,

listed

i t si only provides difernt

0.0

15.0

yb

sta istics

data

pres nt

12.5 0

rdeg.1

obtained

the shown

LO

7.5

h

in

)+K

time yb

Fig.

DWIA Table emphasiz d

12C(n+,Kf)i2C 5 times

obtained solid

cal u tion reaction

valu b e

sta es

2.

1.5

4,

bet er

In lines.[21]

of

information spin

than

the

spectros py

1 wer

that

10.

[&.I

yb The

also

figure,

partners

reaction

the

fit ng

are

comparison

15.0

12.5

reliab

the the

overal and

measur d. on

etc.

the

241

4.

HYPERNUCLEAR As

y RAY described

in

the

SPECTROSCOPY

introduction,

the

y ray

for t h o s e y decaying hypernuclear sta es. y ray spectros py for A hypernuclei, since due t o smal cros section and/or wol spectros py with Ge d e t c t o r s has be n scint l a ors since the phot -peak ef ic n y also i t is n o t easy t o operate eG det ctors as ociated with secondary beams s i sev r . KaI scint l a ors. no exp riments P b glas e and y rays by G e d e t c t o r s . The KE 419E . H : n o s r e p s e k o p S ( t n e m i r e p x e Hyperbal sy tem whic consi t f o 1 4 Ge spectromet r sy tem. The overal phot peak y rays was achiev d with the solid angle Ge det ctor wer used t o sup res background y rays from L i, hicw Two hypernuclear wer observ d a s shown in Fig.3 One

7Li

spectros py Howevr,

inte si y

the thought

evn

is usaly under

Althoug

it has

hypernuclear

be n

fo

kaon

hypernuclear

wer

det c ion 15

fo is

.%

wer

the

eficny

excit d

M1

was

)% BGO

car ied the in

counters

from

fo

target

en rgy

out about and

TO S

through

transit on

best

resoluti n

difcult t o perfo m is very much lim ted pion beams. The y ray than those with NaI t o NaI det ctors and that the background y rays wer det cted by ni d e t c t i n g hypernuclear

yield

sucefl

The

coming

the

difcult

compared

enviro ment

Tamura)

det ctors(60

thought and

more

wol

the

ofers

betw n

7Li(7r+1K+)

by

region sur ounding Compton

instal ing

fo

the

% for

2.5

3/2+

1 MeV y rays.

reaction,

-+1/2+

the

SK each and

914E

(7r+,Kf7)

20

051

%

2 \ {

80.0

10

32.1

31.0

50

1.2(@)

-yiH

0

3.

Figure rel vant on

fo

the compared spin5/2+ recoil ng ps.[18]

05 0

the

y ray

decay

right. en rgy

Li,

+

It

the

1/2+ hyperncl i.

was

with interaction

spectrum

schem

was

fo

det rmined the

2E lifet m

150 10

found

6Li

cal u tion discus ed.[l7]

was

transit on

After that

the

line the

5/2+

by iL

and

Hyperbal

f )ta s(G.O

691.7

rec nt

fo

measur d

the

has

shape charge

a broade

state

fit ng distribution

toge h r

with

*

based

was

The

te . l a

0 52

20

peak deriv

on taking

l.O(sys)

05 2

in

the

keV.

a cluster keV shape fo

7Li(~+,

cal u ted

to iL

into

due be

model

peak ac ount 1~

shrinks

K+)iLi cros

sections

reaction.[l7]

y en rgy and the whic cor espond t o the Dop ler the slow = 8.5 ) t a t s ( : : ! by 02 % c o m p a r e d The

A

is shown wer magnitude down

directly to efct

f

0.7(sy )

proces

the the of

with

fo

143

that f o 6Li due t o the pres nc whic is s t r o n g l y dep ndent is consi ten with theoretical Mot ba[2 ] and also by by t h e Hyperbal was car ied the hyperbal sy tem to information on t h e spin-orbit 3/2+ and 5/2+, whic det ctors.[24] I t si emphasized became pos ible with the background. I t is p l a n e d inte sion t o deriv magnitudes double the ficeny fo y ray spectros py The in orde t o observ the i3C. The two y rays about give the magnitude f o spin-orbit demonstrates the powerfuln s

on a rec nt the wer large

to

the

y transit ons

Figure in t h e Strangen s

hyperbal

cluster

out rec ntly D line fo interac ion not esolvdr that the solid-ang e extend the f o spin use MeV

10

fo

HYPERNUCLEAR

5.

with

predict ons

a A hyperon charge

fo the

interaction.

fo wer

4.

Hypernuclear

fo

20. production

from

the

STUDY

spring

is

distribution that

el m ntary

the

B(E2) hypernucle s.

value

f o the a glue like cal u tion. 23][ Hypernuclear also orf t h e ’Be(K-, 7r-)iBe BNL AGS. I t is exp cted through the split ing fo in t h e previous NLB hypernuclear y r a y spectros py hig eficny Ge a r a y s measur ment t o other light dep ndent interaction qualit vely. under yaw at t h e sametime. NaI scint l a or ar ay asw A 2/3p and 2/1p sta es clear y det cted and the This exp riment is t h e ray spectro y. [25]

EL CTRON

sy tem the

on

claimed

WITH

Spectromet r in

based

in

role

the

exp riment

to

to

hypernucl i

very en rgy

provide with

that

s1

hyperon

spectros py

reaction,

transit on shrinkage

partner Ge

can

rec ntly

ground difernc

by moving

precis on using handle An

the second

A

fo

y-ra

the The

levs,

det ctors ef ort

with

NaI large

an

ap lied state example

that

C. Hal with

The

exp riment el ctromagnetic

is schedul probes

to fo

wil

BEAMS

Jlab proces

fo

has

14

be n tions production pres nt d states

studied on

for

by

the the

in

on

strangen s this

tag ed

various a carbon

symposium,

target phot n

reaction production

chan els

beam

[26]

by

the

though would

with

the

tag ed be

spectros pic

until phot n difcult

nuclear

Howevr,

now.

target.

beam since

study

at the

Tan shi-ES for

ther

Only

beam is a uniq e

the

are

rec ntly, hypernuclear inte si y

wef was

quasifre reported

invest ga-

bound is ow.l orf t h e hyperbe n mostly amplitude sta es t h e reaction ac es ibl f o thes react o po ulate target make hypernucle s. power that a Even achiev d when pos ible beam spot Thus,

as

A

On the otherhand. a n el ctron beam in t h e GeV region to l nuclear study. In contrast t o reactions with r , K meson beams whic have used for t h e hypernuclear experiments, the (e, K+) reaction has large spin-fl at 0 d e g r s . Thus, it excits both spin flip and spin no-flip hypernuclear siev n multaneouls y. In ad it on, contra y t o the (T+, K+) and (K-, r-) reactions, a prot n t o a A hyperon and produces A hypernucl i whic are not by converts such reactions. Iso pin multip e sta es wil b e investiga ed by c o m p a r i s o n tion spectra. Particularly i n t h e light mas region, the (e, K+) reaction tends neutron rich A hypernuclei. For example, the (e, K+) reaction on the 7Li it pos ible to study a eH; hypernucle s, whic would be t h e neutron hal o A From t h e experimental point f o view, the (e, K+) reaction has a potential wil wef realiz hypernuclear reaction spectros py with sub-MeV en rgy resoluti n. 01 keV resoluti n, whic is compar ble to that f o NaI y det ctors, can be a n ap ropriate spectromet r sy tem is avilbe. Such hig resoluti n becom s becaus t h e primary el ctron beam has exclnt beam emit ance. A smal size a t t h e target and hig beam cur ent a r e easily obtained. ew of t h e order f o 0.1 m can employ smal and thin targets, ev n enrich d isot pes. Ther a r e ef orts for t h e A hypernuclear spectros py a t Hal A and Hal C f o Jef rson C wher the exp riment is schedul to run in t h e spring f o 20, Laboratory. I n Hal t h e experimental setup was design t o car y out in t h e 0 degr tag in configuration. [27] Since the virtual phot n flux si very much forwa d peaked( nearly at zero degr s) and kaon angular distributions are also forwa d peak d, hypernuclear production wil be most eficntly det cted by measuring scat er d el ctrons as ociated with virtual phot ns In t h e per s nt setup in Hal C, a split er magnet is and kaons both a t 0 degr s. instal ed im ed at ly downstream f o t h e target as schematic l y shown in Fig.4 Scat er d el ctrons and posit ve kaons are bent t o the op site direct ons and guide t o the ENGE spectromet r(6 msr) spectromet r that tags el ctrons from 043- 2 MeV/c and t o t h e SO that det cts kaons around 1 GeV/c when the beam mo entum is 1.645 GeV/c. Although it h a s i t is know that the (e, K+) reaction s i invalu b e to the hypernuclear study, becom feasibl only rec ntly a t Jef rson Laboratory wher hig inte si y CW el ctron beams are ac el rated. In ad it on t o a go d resoluti n kaon spectromet r, i t is also requi d t o have a scat er d el ctron spectromet r that has go d en rgy resoluti n and can det ct hig rate el ctrons whic are as ociated with bremstrahlung from the target. The Hal C setup with a silcon strip det ctor ar ay that covers t h e 07 cm focal plane fo the el ctron spectromet r works l ew under such envro ment. Experim nt for t h e p-shel A hypernuclear spectros py( E89-0 : L. Tang and E . Hungerfo d) is in proges with targets of .iL 7Li, 9Be. log. B and C. I t is also plan ed t o extend the investiga on by t h e (e,e K+) reaction t o a heavi r target(E97-08:O. Hashimot and L. Tang) and explore the A hypernucl i pos ib l ty t o car y out hig -resoluti n hypernuclear spectros py f o heavi r with el ctron beams.

541

SUM ARY

6.

has teraction. obtained reaction nuclear

AND

Through

great

sign f ca e taking spectroscopy spectroscopy

y ray

the

rec nt

Now,

for

quanta ive advantages

spectroscopy cru ial information f o A hypernuclei is e x p e c t e d

giv n

study whic

Table Comparison

FUTURE

2 AZ

neutro

with

with

A hyperon

fo

=

the

with

dat ,

the

its

the

f o new

structure

the

A

det ctor

prot n

fo wil role

reactions

tion expl ored, hypernuclear beams E140a,

further

Although

The

near

be

and 2-30

be provide spectrosc py, threshold ray

the expande keV(FWHM)

as

wil

key

fo

information

requires

C are author

hypernuclei for

av ilab e E3 6,

whic

the

pres nt spectrosc py

in

greatly.

rev al extende

spectroscopy

listed

ne ds

hig er

new

E369,

with

on much whic

thankful

much

in

us

ac es

pa er

for

in

had

the

A

deals (T-,K+) the

ac el rator

hypernuclear We

some particular,

years

en rgy

at

A new

Jef rson

AN

and ago,

the fo t h e Hypernuclear

value

eficny.

in-

can

K+)

(T+,

A hyper-

be

resolution,

spectrosc pic

Laboratory,

hypernuclear

parts ke ping

regim E89-0 ,

reaction. discu on

hig eficny.

spectrosc py

prog es facil t es

Beyond

become

be

explored

and reaction

a new f o the sta es

in

virtual

AN

Ge above

det ction

as particularly

the

wil spectrosc pic interaction.

the

play

its

few when col aborators

sub-MeV

the

wil hig

with

or

PS

intensity Profes ors

waited fo fo

ev n

and reaction emis on

while

years

GeV

be a sign f ca t

The

nucleo

i t is eagrly

variety studied

studies

ar ay

A hypernuclei,

05

wide

to

det ctor eficny,

fo

last that,

pos ible with

(y,K)

with

hypernuclei with

y ray

the such

E97-08,

sta es

transfe

structure the

fo

moentu

moentu

wil

sta es

wol atomic

parity,

(T,K)

large

(e,e K+)

eficny

with

S=-2 Jlab

]71[

at via

flip,un at r l

virtual

expect

det ction mostly

usef l

yield,

the

t o the

important

the

det ction

spectrosc py

structure

spin

spectrosc py

dep ndent

resolution

the and

yrev

Hypernuclear them,

In

its unpar l e d interaction. si in prog es rich A hypernuclei.

large

TO)

K+)

hig er

spin large

by plan ed

E419

en rgy

the

dream

AN

sub ti onal

TO)

spin

fo

resolution.

the

established

hig

A hypernuclear

the

stre ch d, ig

2.

Among

aspects

al ows

example, is

en rgy

hypenuclear Table

proved

has

A hypernuclear

tnem oc

A

(K-, (K-,

(P,

op ortunit es.

recation

neutron

reactions

1-

that

the

and

)OK

stop ed

A

beyond

ar ay fo

to

( e l e K+) (p,p K+)

fut re,

experimental

=

thgilf-n

T-)

T-)

fo

wer

spin-dep ndent (e,e K+)

(T-,

(K-, (K-,

learned

spectromet r resolution

AZ

( e , e Ko) ( P , )OK P ( P , )OK

In

whic

the

K+)

in-flght stop ed

have

SK

go d

Ge

on

with

ew

investigation

production 0

to

,+.(

prog es ,

rev al

to

PROSPECTS

be

investiga-

JHF. KE -PS

wil wil

-y

the further kaon

that

H.

146

Tamura,

L.

D. J . Milenr

Tang

M.

and

and

Sot na

E.

Hungerfo d.

the

on

Discuion

theor tical

with

aspects

Prof.

are

T.

also

Mot ba,

greatly

K.

ap reciated.

Itonag ,

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Physic (Seoul9 ) Let .

p.23,

8 189

135

19 5,

(1983)

(19 4).

02

and

Sigapore, Sigapore,

edited 20)

;

Univers ty Private

edited 20)

Academy com unicat on

to

be

to

be

K.

Hadron 02

dna Maruym

Nuclear

dna

Elsevir

Scien

Spin-orbit

B.V

Electromagni (Editors)

Al

S.

L.

K.

L.

Minami , Y.

Ganf,

sthgir

Paschke , Tangf

Shim zu ,

Y.

Carnegi

fo

L.

Hampton

Toky ,

with is doublet

from

the

340

Alternate keV sta es

(-2

York

precis on. FWHM MeV

in

H.

Noumi ,

H.

Tamur ,

ASU

ASU Freibu g,

Germany Ibar gi,

305-81,

Japan

Gre nsbor ,

NC

USA 2741,

Japan

1/2-

i3C

Sak guchi ,

Japan

Univers ty,

and Gradient whic

A.

ASU

13-0,

FWHM).

1973,

1523,

2368,

J . Franzd, Matsuoka ,

K.

Jap n

Tsuk ba,

980-57, measur d

Tam g w ,

J . Naknog,

Saji ,

560-43, weN

AV

Sendai

hig

Toynak

Frankli,

E.

T.

Organiz t on,

T State

Univers ty,

G.

Kish mot ,

D79104

Toky A

sucefly

Sut erb,

T.

Morikub ,

Rusekb,

Herman -Herd -Str.3, Res arch

Carolina

K.

.A

PA

Hampton,

fo

Eugenio,

R.

Pit sburgh,

Univers ty,

Wniversity

Mori ,

Quin,

M.

Khaustovc,

Upton,

Ac el rato

y-rays

Sumiham ,

Yuanf

T.

B.

.P

.P

1- ,

Freibu g,

Energy

Toh ku

Pileb, M.

Universty,

dUnivers ty

Bro khaven

Miyake,

.P

Chrienb,

Laboratory,

Melon

wer

E.

Hay k w ,

and

Nation l

hNorth

147

Machik ney ma

bBro khaven

The

resvd.

i3C R.

H.

Univers ty,

High

Probes

fo

. S Ajimura ,

Kohri , Fuk da , Mayb, Outa , Saw ftah, Tanid g,

Osak

en rgy the y-ra s spectromet rs 3/2-

htiw Okuno

split ing

H. T. M. H. R. K.

i3C

Physic

H.

The

is a b o u t

yb

3/2-

(K-,

doublet

using

is much The

27

reaction

T-)

150

Synchrot n. obtained keV

sta es det c ors

NaI

bet er

at

than (prelim nary).

The smal

on

-11

an those

to

en rgy split ing

enrich d

obtain

VeM

obtained

the I3C

resoluti n en rgy

to

the

spin-orb t by

ground target for fo

using

the the

split ing

was magnetic 1/2-

11

state used

in

at MeV and

148

INTRODUCTION

.1

K+) The domina t of

fo

exampl :

Since phenomlgica the

the nucleo

yb

the

peaks

A to

f sta es

observ d.

the

saw

are

bosn

wen

of

K-

fo

two

split ng. 1.56

exp rim nt in

than

exp rim nt They

col ab r ti n

sta es

also exchang

for

r-)i3C

VeM

s el

K+)igY

the

model

split ng

the

interac o

exp rim nt

with

re-anlysi MeV.

are erfomdp D, F a n d A-nucles with

the describ

Our

exp rim nt

other a wen

the pstate y)iBe

ind cate

in resolutin has

the

eW

[6].

of

betwn

spin-orb t

hig

above.

the

KEK

models .f79CSN

BNL,

to

the

exp rim nt

framewok interac o

more

single

the

interac o

exprimnt

at fo

and

the

split ng

of

exp rim ntal

predictons

split ngs other

hand, hig

the

adv nt ges

of ]9[

sta i cs

on

quark

[lo].

data

the

models

revo

[7].

+

with

previous

excitd for

orde

The

split ng.

rof

enrgy

yb

the

f-sta e

to

the

[8]. using

conlude

el ctromagne ic

-bo

the

i3C

yb

almost

eloh

saw

yb

observd

A model to

lit e

saw

MeV.

the

in

[(p1/2),l 3 A]

an

exp rim nts.

saw ind cate

VeM

predict

most

2/3p 0.3 obtained

VeM coletd

spin-orb t 0.96

3a

si necsary

exp rim nt

reaction

and

split ng

ind cated

and

0.75

that

The

a wef

split ng

of microsp

of

i3C also

the

roF

that

of than

the

that

split ng

2/1p

s el

of

than

fo interac o

in

saw

same

large

[(p1/2)i1(p1/2)A]

be LNB

suget

the

[(P3/2),’p1\]0+

smal .

one

The to

split ng enrgy

using

at

peak

deg n rat .

[3].

contribu es

ben

(r+, [1] 2 .

that MeV)

smaler

years.

neutron enrgy

surp i ngly

the

interac ion

ind cated

82-(

quark

has

02 spin-orb t

CERN

a large

2/3

be

than

y-ra

almost

difcultes, A-nucles

to magnitude of

A split ng

are hand,

and

strange

suelc n-A

emulsion

the

poten ials

roughly

A is estima ed

the

a relativy

perfomd

great

for

the

found

orde

that

exp rim ntal of

saw

split ng

theor ical

predict On

The

to

er w

smal perfomd

Observd

configurats

(OBE)

of

the

-r

also

the

at

On

at

[(p1/2),’A]O+

one

spin-orb t physic

fo

esolc

split ng

gBe(K-,

[5].

perfomd

The

si very

parts

roughly

of

due

structure of Wods-axn

esu interac o

explaind

A-nucles exp rim nt

The

split ng [gBe(2+)@(~1/2)~]3/2+,5/2+ 0.1 MeV.

saw

limted gros

the

dep n t

ind cat o

The

the

with

naively hypernucla

first

[4].

f 0.12

spin be

smal

MeV).

extr m ly A-nucles

r-)i60 configurats

discrepan

198.

the

can

The in

the The

0.3

spin-orb t

It

160(K-,

(6.17 150

be

cal u tions

with

6 MeV. 13C(K-,

[3]. force.

are clarifed

an lyse fo the

part

While,

spin-orb t subjects

data have

central

nuclear

in

data

zero thes

EXPERIMENT

2.

the GeV/c, The x

cm

scat ering

nucleo.

the to the inter sting Experim ntal y, nevig servd about sta es In t h e as 0.36 smal doublet has "Y(T+, A saw confirm European split ng in i60 Ther One The Nijmegn split ngs A discrepan probe

of

AN

reaction

The

and K-sl pil (4.5

hig exp riment:

and

y)i3C

r-

and

split ng

scat er d

p-,

(T-:

lo4

i3C T-)

13C(K-,

spin-orb t

to

of

particles

T-

e-)/K12.0

sup re

mc the

s).

in-flght

ratio thick.

The the

exp rim nt i3C

with of The background

hig

the

C31 decay

active

benz

saw

a t 0 t o 16 beam inel

of

target

K-

perfomd precison.

degrs target

due

saw

about saw

er w

si a seful the n-flight si a main background. to

at

The an

D -SGA LNB ENILG 0.3 active

det c d

K-

beam

devic

Typical

yb targe

decay

mo entu

to

beam

Especialy,

det c of

to

48D48 of

6.0

K-.

inte s y the

saw

spectrome r. cm In

kaew ew

measur saw

wide, the

0.93

decay measur

1.5

(K-,

5

149

y-rays, t h e of-line 7r-)i3C 30.5 1/2the two the C" fo the 8.9 The Dopler en rgy fo the using us t o t o theoretical domina tly excit d enabl s Da t a 1.4 x

show

One

In

cm

and

segmenta ion

MeV

NaI

core,

wer sta es

and

located

3/2-

are

det ctors y-rays

the

doublet

MeV.

Kin

mainly

a pure

shift,

and

fo

from

in

at

reducing

spin-orbit

sta es the the

decay

7r-7r0

t-

active

target 10.5

cm [12C(O+)@(p1/2,p3/2)~]1/2-,3j2-. hig .n(%185

at -11

split ing

from

producing played

background.

en rgy

y)

an

the MeV

the NaI det ctor i t si necsary to resoluti n f o the NaI det c or 1 MeV y-ra . I t is roughly one t h e magnetic spectromet rs 2-( measur en rgi s fo the doublet cal u tion on t h e cros - e ti n excit d at the forwa d scat ering at t h e large angles f o -13"[]. us t o s e p a r t e the doublet sta es, x 9ol K-s erw col e t d with 2.1 9ol K - s wer an lyzed.

target

region

reaction

two

important 27

to

cent r

the

can

be

NaI

det c ors

must

in measur

state

By

in

particular y

becaus

role

to

ground

observ d is

y-ra s

in i3C.

the

ident fy g

fo

6.4

virtue

sup res d.

The

en rgy

close the

than

state

the important

cor e tion

those resoluti n

tens

al.,

eW target.

for

the

keV.

the

to 11

used

the

fo fo

the MeV.

fo

Typical

det c ion

obtained

the by

enabl s

Ac ording

state

is

reaction

T-)

adv ntages. stably

col e t d

x

spin

is domina tly

(K-,

cm

from

O+ calibr t on

1/2-

In

13C(K-,

6.4

x

y-ra s Configurations f o the

is

is lsoa important orf the en rgy endure hig counti g rate near is exp cted t o b e 340 Vek FWHM orde f o magnitude bet er VeM FWHM). The bet er en rgy sta es with precison f o a wef by T. Mot ba et angles. while the 3/2The angul r distribution fo whic is one f o the most on t h e t a r g e t . and the data

the

cm

the

i3C.

important.

en rgy

be

with

RESULT the peak

angles 5.6

The escap the VeM dep n ce, The Observ d from state domina t The "C. scat ering observ d. 4.

reaction

the

an lysi ,

PRELIM NALY

3. 3.1

ther fo e

e rf-isauQ

quasi-fre

region

region is y-ra s from a n en rgy spectrum f o 0 t o 7 degr s MeV is perfo med si hig er gaus i n peak. The measur d en rgy resoluti n with n the sta istical a n estimated en rgy resoluti n peak structures at the 7/2+ state at 6.17 MeV to comp sit ons other peak is y-ra s Fig.l(b) show an angles of 0 The amount

f o the 13C(K-, the +2 s t a t e f o y-ra s are sel ct d. with the functio for t h e ful en rgy & 81 is 20 er or. en rgy is t h e same a t 2. MeV 2.164 VeM the ground f o the target from the en rgy spectrum t o 16 degrs f o the background

at in en rgy Vek

T-)

A

of

reaction, the fit ng

what

fo

ew

to

two

peak, ful

en rgy for

the

ground

6.2

the plan ed

MeV

two

to the

gaus i n and

histogram the

The

en rgy

relation,

the

the

11

state The quartz

are

peaks region,

is VeM

to

in

thought

achiev

domina tly state

wher

ad ed

rewol

peak

are

ground

is

AE

almost

4.

in to

gaus i n

the the

in

the

& cx

region

27Si

and

to

befor

y-ra s

cor espond

is

the

is

scat ering

T-

rt 0.8

y-ra

observ d. "C.

340

linear for

MeV,

same for

keV

the

the exp riment.

the

Fig.l(a)

3.0

fo functio .

to single

as FWHM.

en rgy

4.39

t o y-ra s the 3/2state in 1 5 0 . 8Si2 and 60l nuclei are the most cel made fo with to al thicknes fo 8 m. +1 state (T=l) a t 15. 0 VeM t o the ground state of y-ras in t h e quasi-fre region, wher the are sel ct d. A clear peak at 1 5 VeM is d o m i n a t l y around 1 5 VeM si much les than that around to

and

VeM

quasi-fre

the FWHM.

As uming

resoluti n as

4.39

and

from

in T-

051

2.50

2

02 Y

9 0

.

60

IS0 4-

u2

01

40 U

05

20 0

Figure to

3.2.

Bound

An

scat ering in

spectrum the

simulation.

the

that

up er

%

50

fo

fo 340

two peaks is e s t i m a t e d pres nt

the

Ther fo e, sy tematic en rgy help

angles estimated

the

The

the Vek

spectrum

estimate

er o

gaus i n

peak.

gaus i n. are

in

the exp cted

en rgy

sy tematic in

obtained the

keV

in

are

peaks,

perfo med

result,

sy tema ic

each

keV

mainly with

(up er)

ratios

of

for

fo

other.

the

er o s

the

is

with fo

are

rewol the as

consider g

sy tema ic

er o s

in various er o

fo

same contribute simulation

the

fo i 3 C 9 t o 16 the 1/2-

the

en rgy

consi te

spectrum.

Strengths

split ng NaI

fit ngs

in

the

en rgy

02

the calibr t on

to

functio s

peak,

ew

should

exp cted.

and the

Vek

is for

fo

the not

split ng. such cor e tion

in be

angles

fo is used

ap lied.

3/2-

the

be n

1/2-

Fig.2,

the

rewol 0.51

at means

The two

thought

and

to

For

a functio fo

the The the

to

more

be

the estimation

simulation Dopler

Monte

the is

rewol

estimated

hig er

difernc

scat ering

the are

to

gaus i n the

3/2-

sta es. al cor e tion

fo

about

in

peaks

the MeV

the

sel ct d.

are

ad ed

the

en rgy

for

en rgy

fo

estimated,

wher

peaks

escap

0

fo

are

sta es

result

fixed

the

in

(lower)

gaus i n

and

is

the as

fixed also

observ d single

the two

20

scat ering

(b).

and

fo

det c or

(MeV)

is shown The the

are

mixng have

Energy

the

degr s fo with

gaus i n

gaus i n

er o s

degrs

functio

en rgy

yar-y

at

region and

about that

The

region

61

the

ful

15

0 to

rewol

same

yb

the

betw n

the whic

the

calibr t on

becaus to fit ngs,

in

Widths (prelim nary).

en rgy

to

quasi-fre

I0

A bound

is

Posit n

the

angles

the 8:2

and

Sta istical almost

the

in

9 degr s

051-

v

8

y-ra s

scat ering

closey

en rgy

is 09to be

(MeV)

y-ra s 0 to po ulation

ful

FWHM.

er o s

are to

Fit ings hig er hig er

split ing

shift

spectrum located

escap

prelim nary

er o

fo

Energy

fo

the

fo

the

The

single

at

region

are

fo

6

yar-y

spectra

and

(a)

en rgy

spectra

the

4

Energy

.1

7 degr s

7r-

Theor tical y, 8:2 both about Carlo expon tial. for than width gaus i n . fo sta es In sy tematic obtain g angles. Dopler the the also

2

doublet smal

yet.

in fo

sim lar shift.

wil

the

fo to

A

15

,8,

0

’

, ’

b’ ’

’

’YO

’I ’

’

’

’Y.2 ’

’113’

"9

Figure Dopler

2. to

shift

16"

Energy in

is perfo med. t h e rewol

spectra

fo

The

spectrum

y-ra s

in

scat ering

are

sel ct d.

"2 ’

Energy

,

,A ’

(MeV)

A bound angles

the

4IJ" ,

’

yar-y

region. of

0"

to

The

"9

in

the

en rgy

up er

cor e tion

of

spectrum

and

the

REF NCES

.P

.1 2.

T. W.

3.

H.

.M

4.

5. 6. 7. 8. 9.

1

10

M. T. the Toky , R. E. 0. H. T.

Bruckner May May

Nag e

1

H. Hiyam

e t al., et et et al., et al., et al., GeV/c region, 19 5) 175. et Dalitz e t al.,

Pile

Haseg w

Morimatsu J . Pirner Mot ba

al., al.,

Phys. Phys.

al.,

Rev.

Phys. Phys.

Int.

et e t al.,

et al;

Phys.

INS

to al., private

Nucl. Phys.

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symp.

eds. be

Nucl.

published.

Let .

Rev. Let . Let . Let .

S.

Let . 79B

Phys. Let . com unicat on.

74

Nuclear

A Phys. 14B

47 (1978)

(198)

51

on

Sugimot

6

258. (195)

(1983)

2085.

and

Particle

Hashimot

(197) (1982)

24.

157. 106.

0.

and

625 024A

(19)

(1984)

71. 308.

573.

Physic

(Universal

with

Academi

meson

beams

Pres ,

in

ThisPageIntolyLfBk

ThisPageIntolyLfBk This Page Intentionally Left Blank

V.

N-

COR ELATIONS

PHYSICS

AND

FEW-BODY

ThisPageIntolyLfBk

ThisPageIntolyLfBk This Page Intentionally Left Blank

Hadron

K.

’

dna Maruym

02

Nuclear

dna

reiv slE

Physic H.

Scien

htiw Okuno

(Editors)

B.V

Electromagni lA

sthgir

Phot dis ntegration Beam

Scien ,

Hirosaw,

.1

INTRODUCTION

such project In

cros yb

in in

modes

ew nucleo

51

3He

fo

and

TAGX

at

4He

Suda"

2-1

fo

resvd.

reactions

T. "RI

Probes

yB a

rewop

extracted, phot dis ntegration sA nucleo

The

insde

3He since

the uclearn a seri section a kinemat c l y detail. two ucleons contribu ng have uceds comparing sy tem In t h e npand for In

this One

A

the

may evaw

build ng

and the fo

case

2N(p )

two-nucle the

of

p - air and

pair

compared

s i surp i ngly the independent-single-particle dently in a nuclear-mfid nuclear reaction in a nucles.

phot dis n egrat o

ew

pres nt

the block

the

deut ron sy tem

whic

a nucles. section

mechanis

measur nt 2N nucleo-

of

proces the

that most

phot dis n egrat o

deut ron

measur d.

section

with

of ’phot dis ntegration’

using

the

3He.

and

exp rim ntal

microsp

roF

the

4He,

to ben

prog am,

the region

explor

a ediw theori s, section

the

cros

[l],

ew

the difernt

reaction evah

to

be

separ tely

Ey

one

phot n

section

a two-nucle mediu

may

study

from

the

in uclei.n a uclesn si onsiderc t o be suceiv nucleobut our understandi g on t h e wo-nuclet olisnc po r. The best odelm t o describ uclein si t h e ean-fildm model, ni whic a ucleon si sumeda poten ial. It ac ounts rof ariousv pro e ti s el,w but this model can not describ woh wot ucleons The measur nt of t h e ’phot dis n egrat o ’ of a nucleo of

2N(pn)

yb

’phot dis ntegra ion’

first

the

evaw

in to scat er

theory

has

be n and

extnsivly

functio

in

of colisn based

fo

nuclei pair

4He

nucles.

nuclear evom

-owt yb

3He

be n

and

time.

the an lyzi g

the sy tem

evah

study

MeV).

absorpti n absorpti n

the

absorpti n

and

rof

ecrof

ident f ,

rof

TAGX reaction

at empted mechanis

phot n phot n can

01

2 be n

reaction

sy tem .

the mechanis

(E,

range

rof

det rmined,

of

obtained of

nuclear

few-nuclo

prog ams

enrgy

phot dis n egrat o

ben

result nucleo-

in

phot n

revald evah

cros

separ tely

TAGX. the

forces

invest ga

revo the

ben

one

has TAGX

at

rof

of

kinemat c l

proces

section

exp rim ntal

aimed

a ediw enabl d the

of

cros

main interm d a

measur nt

have

cr2N(pp))

also

the

cros

phot dis ntegration, with

the

In

2N

the

of

prog am

in the

covering

,yaw

cros

has be n

the

functio and

nucle s,

reaction

one

This

4He

(cr2N(pn),

cal from

extract

2N a ucles.n 3He

prog am.

in

the

phot dis n egrat o

be n

1980’s.

and

complet

to

in

the

has

of

(2N)

the

JAP N

fo

TAGX 3He

domina t

Saitam ,

4He,

end

phot dis ntegra ion

this for

The

pa er,

the

studie of

measur nt

as

RIKEN Wako,

each

a

mediu

on

indep insde

other

and a

156

nucles

The

deuteron

one

si

fo

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163

10

9.

Figure dis ntegration

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164

4 3

b 1

n

02

10.

spin- glet due dipole El result cal u tion state chan el p -sta e.

to The

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The

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the p )n may

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Figure 150

3N phot ns

notice

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t 0

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The

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20

Figure

et

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42.1

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3

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1

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+

0 03

02 10

YE Figure The geth r. cros

14.

data

In

for

The

section w h

Comparison

Ther

E-,

A

20

0

some

0.6

b

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.3

*

a(yd->pn)

I \

04 5

W

1111.

a theory

data

Fig.

of

them

are

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rewol solid

sevral [12, 3].

14,

the

E-, a scaling

are

swoh

factor

with data

det rmined The

2N(pn)

YE cros

set deut ron

the

rewol the cros

1.24 si also plot ed. The sim lar ty that of t h e deut ron cros ections si rema k bl . eW can conlude in He3 cales to that of t h e deut ron Figure 15. hows 4He(y,pn)d scaled deut ron phot dis n egrat o si our surp is ng t o find that ther 041 MeV, hicw si n o t bservdo

section.

plot ed

fo

deut ron

2N(pn)

toof

1.24

,.E 3He

data and

section phot dis n egrat o that cros

Figure The geth r. cros

revo

4He cros

of

for

cros

the the phot dis n egrat o section

si a igb ni t h e He3

3He

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phot n

case.

rof

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section.

E-, line

yb

TAGX

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cros

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,.E

absorpti n

To

with

section range

7E

rewol confirm

a factor ro j u m p

revo

is

plot ed

a scaling

of

the cros

data

from

section

thres old

cros

are show

a scaling

section.

plot ed

the factor

E-, toge h r

with 2N(pn)

40

(MeV)

4He(y,pn)d

a t rewol

with discrepany

data

15.

03 20

01

(MeV)

3He(y,pn)p line

0 40

deut ron

6.0 of

region,

and with

cros of

to-

the

to

a idew -,E range. .18 -41[ In t h e figure, of 6.0 si plot ed toge h r. in magnitude around t h e absolute magnitude

section

rewol

50

factor

of

VeM

np- air

the fo

,.E

the

to

It =

I

761

cros

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section

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p)

(7,

that

mo entum

obtained

the

cros

e t al.

TAGX,

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]91[ was

section

absolute

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are asigned

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plot ed

of

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the

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the

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5.1

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The

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bump

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Hom a’s

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140

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at section

16

cros

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around

agremnt

si cor e t.

60

05

04

yb

det rmin

cros Homa

desir

of

to

section

the

2N(pn)

the

understand

the

section

Hom a’s

07

integra ing

of

MeV/c

4He(y,p)

cros

measur d

data

at

the region

revo

de uc

by

around confirm

I

09 80

07

(MeV/c)

e t al.

from

vector.

yb

swoh

= 30"

8p

Pp Figure

Figure

section

h....,.,..,....,....,....,....~

30

inclusve

observd

4He(y,p)X

p ) cros

TAGX

[19].

Solid

cros

what

for

4He(y,p). 4He(y,

is goin

cirles

pn)d

section

covering

on

Open

wohs

at

cirles

the

cros

section

the phot n

this

wohs diferntal

integra d

phot n

the cros

enrgy enrgy.

of

CON LUSIONS

In t h i s and 4He neutron measurem nts absorption absorption cros section A icrospm Phot n extracted. n p cros a realist c

fo

pa er,

measur d

ew TAGX yb

absorpti n section,

evaw

proces saw The

enabl d a kinemat c l y in

the found

cal u tion cros functio

pres nt

with

np- air

the

yb

two

section

suced two

to

have suced

the

result to

nucleos

saw

to yb

and

su

TAGX

det rmin

be prot ns

saw difernt

revoc

complet

in

quite

simlar found to

the

fo

spectromet r.

to

the

a ediw .yaw

rep oduc in rep oduc

E-,

to

This nucles.

rof 3He

phot dis n egrat o

3He

to

dep n c .

be

saw

Large

kinemat c l

saw and

that about

ac ept n

the also

of two

the

magnitude

observd

range, esntial

The cros

4He,

to al

and deut ron

the

A

exp rim nts rof

orde microsp

cros

section

the and

to

E-, revo

phot dis ntegra ion.

identfy section

the

to

cros

cros

perfom

the rof

a wide cal u tion

for

prot n

dep n c

the

smaler of

and

both

section

than section,

3He phot n phot n

E-, that

and

the

of

of

range.

the

using

saw

the but

168

by

failed and

two

to

prot ns

the

ac ount

saw

prelim nary

rof

E.,

the

measur d result

dep n c .

to

are

study

pres nt d.

The

the

an lyzi g

phot n

power

absorpti n

rof

the

yb

phot n two

absorpti n

prot ns

in

detail,

REF NCES .1

2. 3. 4.

5.

6. 7. 8. 9.

10. .1 12. 13. 14. 15. 16. 17. .81 19.

H.Arenhov1 Sup l.3 Maruyam M.Kobay shi M.Vanderh g E.Jans T.Emura S.Endo, T.Emuar T.Emura K.Maruyam K.Nik , .P .P .P B.L V.N A.N .uY F.Balestra F.Balestra S.M S.

(Springe -V la ,

Wilhe m, Wilhe m, Wilhe m,

.M

Hom a

and

.M

e t al. and

e t a l . , ucl.N e t a l . (TAGX Ph.D. thesi , e t a l . (TAGX e t a l . (TAGX et Ph.D. thesi , J.A J.A J.A Berman S.C Fetisov, A.N Gorbun v, Arkatov et al., e t al., Doran et a l e t al.,

(TAGX

Sanzo e, K. ond ,

e t al., Phys.

Nucl. Journ.

al.

(TAGX Niskane Niskane

Col ab.)

Gorbun v

Nucl.

Phys.

A475

Col ab.):Phys. Col ab.)

Col ab r tion)

Journ.

and

and and and

A59

.786

Hiroshma

Sci.

H.

H. and

Phys. Nucl. A59(13)47.

38(197)45.

(195)

Hiroshma

Let .

Rev.

Methods

Methods,

Rev.

Rev.

Phys.

Univ.

C 94 Let .

Univ.

Phys. Phys. Phys.

Arenhovl, Yergin,

Arenhovl, A.

49(17)5.

Phys.

(1987)

lO(196)

T.

Phys. Varfolmev,

1623.

1(970)63.

37

862

A57,

Rev.

673A

(194) 47

A5,

weF

A376(

.912

: Phys.

Arenhovl,

H. P.F

Instrum.

: Phys.

:

J . ucl.N e t a l . , Sov. J. Nuov. Cim. Nuov. Cim. Nucl. Phys. Phys. Rev. 36C Sov.

(1987)

De u t e r o n ,

fo

Nucl. Instrum.

Sci.

Niskane Fultz

Photodisintegration 19)

Wien, Col ab.):

(195)

Let . Let . Rev. Rev. C10

19.

Nucl.

(19 6)

System

196)35.

35.

R597. 193.

(194)

Body

.40 1035.

B39(17)25. 53 B Let . C51 (1974)

(19 5) Phys.

47

(19 4) 21.

(19 5) 71

109. .1482 (1965)

1034. .503

Hadron

K.

and

02

Maruym

Nuclear and

Elsevir

Physic

.H Scien

htiw

onukO B.V

Phot nuclear thre -nucleon

cros

G. 05 83-1

W.

Orlandi ,

Departmen

fo Pov

bRus ian Kurchatov

Res arch

role

ap lic t on

After

a brief played

yb

are giant

an lyzed

1.

INTRODUCTION

have

knowledg

dipole

One tromagnetic t o understand sizable mechanis .

of efcts reach d

of

In

fo

in

thre-nuclo

to al

weiv

of

whic ad res ing

other can

the nuclear a eryv conti u m

stil t o d o for kinds of ap roximat ons I t si certainly problematic body orcef from spurio sta ist cal (numerical). In orde t o cirumvent ago the LITM saw pro sed, using bound state techniqu s

hig

Efrosb

OW0

and

Rusia

the

secrof

isue si t h e be

observal,

the

in role

Lorentz

Universty

si discue.

of

the

of

misng

exp rim ntal

study thre-body besid

the

isue,

obstacle a method [l].

howevr,

uniqely

integral

H3

of

The

of

and

result

wef the

body

transfo m 3He

rep s nt d In

fo

sy tem force.

bind g

the

whic

gniwol f

swol a

yb a sketch

to

the

cal u te

Sask tchew n,

si pres nt d.

enrgis

t o it a n d learn a gib ifcultyd sy tem ni their inalf sta es. While degr of acury in t h e treatment sta es. Thes sta es are very ifcultd one si fteno forced t o introduce can t o disenta gl the presumably not fects introduce y b any ap roximat on, this

ascribed

the

role

kaisumoT

Physic,

about

the

Institute ,

Engier

clarifyng

E.L

and

Trento,

,wocs M

phot dis n egrat o

important whic

Kurchatov and

sy tems

of

1238

,1

S7N

introduction

thre -nucleon

Universty

Italy

Physic

the

interac ion

961

V.D.

Physic ,

(nento)

to

the

resvd.

Leid man ,

fo

resona c .

sthgir

lA

forces

Centr

Can da

Probes

sections

Square,

Departmen Sask to n,

Electromagni (Editors)

method rof

the

strength

In

In

thre -body

yb

particular

of

(LITM)

particular

puzle

sy tem the in

means one

3H

fo

dluow

and

the

its

4He

the

-cel

3He,

wohs

ekil

more about i t s orign and s i rep s nt d yb t h e scare the wef body techniqu s of bound sta es, uchm si t o treat exactly, and the mask the fects f o inter s . large efcts f o the thre be i t s y t e m a i c or

conti u m of

the

inclusve LITM

sta es l iw

cros

a wef be

given.

section

years

170

THE

2.

LORENTZ

The

wher

of final

inclusve

the

the

ar ives transform

With

si

\T.lf

fo

the

@(OR,

R(w)

yb

R(w)

help

of

Eo

equation

vanishe

(H The bound Eqs.

method (2)and The

3,

in

with

orde

This Sieg rt’s to this

second

at

large

dt(H

step

R(w)

-

to al

state

i0r)lG)

char te iz s the

form ap roximat on

unretarde

theor m.

fo

ext rnal

directly,

since

cal u tes in

inclusve

the

an case

integral

has

proces

this

imples of

cros

under

set

Thes

section.

of

form

considerat , final

respon

the

transform

a Lorentz

the

sta e

The knowledg

main

fo

kernl

evaw

functio s

it

and

the

idea of

then

integral

the

that

- iaI)-’(H

OR

&J -

-

f

OR

)OS[

iOI)-’d

distance

si t h e

H,

Hamilton

fo

two

k\

ekil roF

Details

step .

si t h e exist a bound

of

the

cros dipole

operato dipole

I t si know adequate

G

and

si d e t r m i n e d

yb

the

(4)

ni

inverso

R(w).

> 0.

the

dpo). That

norm

of

esntial of

this

First and the

pur ose inverso

thus,

state

Eq.

adv nt ge

contra y

evaw

transfo m

functio .

alre dy operato

section

operato

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invest ga

are

as

are

far smal

as in

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the

discue

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cal u ted a set

rof

fo

can evaw

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functio s, as

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fact,

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Ref.[2]

of of

values

SECTION

rof

includes

OI),

@(OR,

si cal u ted

procedu

si olved.s of t h e t o conti u m

(4)

CROS

the

probe

the a ompletc enrgy.

and

excita on

one

enrgy

=

phot absorpti n unreta d

the

an

(3)

the obtain

functio

wohs

OE -

whic

particular

can

to

PHOT DIS NTEGRATION

using

the

one

METHOD

a sy tem

el ctromagne ic

In

yb

proceds

10

THE The

then techniqu s. (3)

to

given

evaw

denot s any

Instead,

closure

+

state

inverso.

ground

0R

a dexif

3.

yb

-

si

w

of

cal u ting

($I$),

si t h e

Eo -

functio s.

state

while

avoid

IOQ( =

01)

=

wher

ingred ts

of

operato

ground

si t o

evaw

at

functio

a transit on are the respctivly,

es ntial

LITM

state

TRANSFORM

respon

0

and

90

functions, are

INTEGRAL

the the

woleb

to al the

efcts enrgy efcts

cros

pion

of range

thres old

exchang section fo

N

studie

si conerd and

s i computed

cur ents

N

her . forces

eW

due cor e ti ns consider

to

the

to

the

@

17

proces. respon

The

functio

phot absorption

cros

R yb

47r2(e2/hc)~, =

? C

to al

section

si

then

nevig

in

terms

of

the

dipole

)6(

R(w~)

wher

R(w) sA one

This method The method" and (UrbVI )

05

shown

has

eW

the

pres nt

as

r-space

and

section

gniwol f

20

the

the

[5]

VeM

with n Lorentz in

result

Ref.

Tucson-Melbr

pres nti g

In

13

our sets

and thre -body theor tical result and Phil ps [9], ation a s :swol f e h t noitargetnis dot hp eht raelcun noitcare studies of t h e d o ton tah yeht tions, eht rosnet snot rp in He. particular the t o include the In Figs. 1 and and tail regions. only the N force are quite also indep nde t the result .

exp rim ntal of

break howevr,

obtained poten ial

esu

a large rof

H3 (TM)

As

equation

the

LITM

Hypershical

number

transfo m

[4].

of

of

has

and

N

3He

R(w)

cal u te

Harmonic

points

OR

ben

done

using

poten ials

N [6]

to

using

the

Argone

ew

models.

imples

(CH ) betwn

41VA include

expansio

0 and "Regulariz t on

the

that

051

MeV.

[3]

poten ial Urban -VI

the

DISCU ION

situation particular

integral [2].

Cor elat d

rof

(7)

W)

the Schrodinge-lk

the

and

AND

Befor

MeV.

=

of

describ

Bon -

previous

the

done 01

RESULT

About

the

be n

rof

inverso

in solve

Eo

-

I ( q ~ z l ~ o ) 1 2 ~ ( ~ f

to

has

4.

theor tical tems.

fd/. =

er w

on

the in

up

result

198 the

a wef

phot dis n egrat o

cros

laciteroeht

the

data section conlusi

Berman,

should exist

from of

cal u tions

H3

be cros

rey M

the and of

3He.

section

Gibson

and

said

about

period tA

of

the

1964-8 Olson and Ref.[7]

that

]7[ Lehman

time

the

er w

exp rim ntal thre-nuclo rof the

sycomparing

]8[

enrgis most

below and

ac ur te Barbou the

and

-owt

the authors of er w judgin sitube d e d e n erofeb e h t latnemirepx stluser rof fo ydob-e rht ielcun nac tse y l e v i t a n a u q eht e g r a h c yrtem s fo [This saw the main isue at that time, hicw led t o compar tive two mir o nuclei]. ehT tnes rp laciteroeht sledom are l its yratnemidu in edulcni ylsuoenatlumis a tne si noc tnem a rt f o e h t lanif eta s -caretni ecrof in e h t telpirt ,noitcare and eht bmoluoC noisluper ne wteb eht In t h e result ew are gnio t o wohs al those drawb cks are cured. In LITM and the esu of t h e HC ap ro ch t o evlos Eq. (8) have dewol a su ful final state interac o and the Coulmb efcts. 2 e w wohs the to al phot dis n egrat o cros section of 3 H in t h e peak 1 One notices a izables tcef due t o the thre-body interac ion. I n Fig. orcef Urban VI result a r e shown. The efcts of t h e Tucson-Melbr sim lar. The gnirewol of t h e peak due t o the thre-nuclo interac o si NN poten ial. The esu of t h e Bon poten ial does not hangec on t h e

eroM

in

Fadev

Faul,

words

krow

l aw

271

0.0 0

’

01

20

.1

Figure

A

becaus

Total

quenchi g

fo

phot dis n egrat o

the

( T;(~H) wher

cros the

peak

) si t h e

triton

gniwol f

of

due

reason.

roF

to

charge

of

NN

3H

50

06

[MeV]

section

the

04

03

ro

so

the

interac o

3H in

caled

the

peak

region.

could

Brems t ahlung

in

princle

sum

rule

r

0.25

exp ct d si alidv

radius.

n

03.

be

1

0.2

-

E

0.15

d

01. 0.5

0 .0

Figure

for

presumably to

Total

2.

Since

its the

sum

’

NN

rule,

reflct

cros interac ion

in due

size. in

to

a rewol

10 [MeV]

08

phot dis n egrat o

the

shrink g

06

sevig Becaus the

invers

pek.

fo

the In

section

ad it onal enrgy

ro

fact

validty

bind g this weight.

fo the si t h e

of

120

3H

region

in

sum

to

140

the the

rule

tail

whic

sy tem

a smaler

region.

sevig

it is lsoa charge more

responibl contribu on

radius

l iw

173

Besid section

obtained poten ial ne t, combinat Thre separ t ly. can is. to force below to becaus efcts in break ne d .

lowering whic

The

MT

but body

The

notice

Only

in

be

pion

the an

inclusve

Ref.[10]

fo

forces

respon ibl "bind g

up

separ t ly.

phot reactions.

imples

invest ga on

compared amplify that

N

the This Malfiet-Tjon

also

range

break

reaction

reactions.

si purely

Eq.(8)

"tcef

sug e t

the

are core

ther thres old.

Sucesfl

for

furthe

fo

that

it in

peak

soft

short

fo

This thre -body

the

enha c d.

Ref.[12]

poten ial a eryv

soluti n an lyzed

si

is

shown.

interac o

tcef

central,

and

tensor

is

obtained up

In

is eryv lit e for a izables This tcef discue the posiblty Considerg one can In t h i s resp ct

the

si

contra y t o .41VA cor elations

this

rof

contribu s

particular reactions

poten ial

above

enha c m t sem of

efct.

the in

hope in

this

an

to

ext nsio

the

be

the

find

Fig.

(MT) the enha c

direct on

have

of

this

the

interac ion, cros

the

cros

oy(uy)

roF

comparis n,

and that

chanels

whic

LITM

the

in

cros

chan els

tcef

result large started

to

pion

section

T=1/2 to

elihw section

in exclusiv

exclusiv

of

the

for has

for

section.

efcts

tail

Ref.[2]

cros

rather alre dy

on

woleb

This investgao

large

tcef

say

thre-body region.

an

owt

N

the

of

alre dy

nev

TRSB

wohs

to

.2

[l ],

isopn

the

3 we

also

can

a pure

peak an

ni

one

of

on

exp rim ntal

that

owt Fig.

to in

an

to

So

contribute

dep n c

has shown

a tensor

the

cros TRSB

comp-

and

a T=3/2 section

chan el si i n t e r s i n g t h e thre -body in t h e egionr with no relation si very inter s g f o thre -body orcef sen it v y si found thre-body reactions [13,4]. It

T=3/2

cros

result

the

thres old considerably.

the

the

si

570.0 560. i5 I

E

Y

0. 5

6540.0 0.035

3.

Figure

comparis n precis force

In

eW

Fig.

Total

08 90

100

phot dis n egrat o

4 the result rof 3He si g o d , ven if t h e data are ne d , espcialy whic are of t h e same magnitude ouldw ekil t o iscud her

110

cros

briefly

are uncertai s

section

ym

pres nt d if

one the

as

120 [MeV]

those

wants case

in

of and

of

the in

130

H3 compared to 4He.

Fig.1

in

140

the

T=3/2

chan el.

to

exp rim ntal det c

exp rim ntal

the In

Ref.

efcts ]61[

result

are the of

the

theor tical

large.

data. More

thre -body result

The

471

, -

0.2

-

3He 1.6 -

2.1 -

Y

-0-

1

0.8

4.0

V14+UI i

0.

obtained with the LITM and exp rimental data. From the realist c forces enha c s the the peak region. Ther , on sem t o be sizable and relat d, on t h e bind g enrgy. Such contributes with 4 VeM to the 4He si n o t only con e t d to t o t h e mean square prot nnot ap ly a s simply. evrthlsN the thre -body force ni t h e resonac it requi s a somewhat Thoug sy tems the LITM can be ap lied other hand one has t o remb thre and fourbreak up chanel body sy tems phot reac i ns realm f o invest ga on of t h e This del Universit

Acknowledgem nts

krow

has

ben

partly

e del a

Ricera

sup orted

semiraltc the

cros

study via

efcts

bind g

the

section

contra y,

charge

pro e ti s

woleb

central thre-body

the are

for

modern pion

the charge

in

realist c

the

[17]. of

computa ional

also

thres old of Isti uto and

extr m

the

the

oS 4He

OTAN

phot dis n egrat o

trof e

So

Nazionle

argument

si

desirabl

also

an

the

largey have

very

tcef the

to

has the

thre-body

the

4He.

interac o s

ac urate misng.

in but

ew

but

radius,

,rev woH

of

ielcun

tail, quenchig

large radius,

yb Scientfa

interac o s

be region

are

nev enrgy.

distance i t dluow

large that

of

ad it onal

efcts

Ther Brems trahlung

lit e of

of

to

exp rim ntal

than

an

exp rim ntal in

forces.

grant

di

Fisca

nucles.

efcts

cros

rof rof to

the

efort

in

open

V. D. Efros, V.D. Efros,

W.

W.

Leid man ,

Leidman

and and

G.

G.

Orlandi , Orlandi , Few-Body

Phys.

Let .

Syst.

B

38

26,

(19)

,-owt

a wen

Min ster0

(194)

in does

role

.031

.152

of

has

force

On

both

in force

section.

thre-body

REF NCES .1 2.

found

rule

Nuclear,

.405179

the

esu

sum

pro tional

orde

N.

is

term

data

the

ecrof-N

thre -body

bind g

invest ga

thre -body

the

it does this in

that

tcef

the the

inter s also

over stima d

learnt

fo

few

the

571

3. 4.

5. 6. 7.

8. 9. 10 1 12 13 14 15 16. 17.

R.B R. R.B S.A McKel ar, C23, D. B.F. I.M (1970) V.D. R.A R. C6te, 269. V.D. A. man , V. V.D. Se

Wir nga,

Machleidt,

Adv.

Wir nga, Co n,

M.D. Nucl.

(198 ) D. Faul, Gibson Barbour

165.

Efros, Malfiet

De Tour eil, R. Lapian ,

N. e.g

Sov.

Efros,

Fetisov,

Leid man

and

in

prepar tion. G.

Orlandi

W.

Smith,

Phys.

Rev.

Scadron,

Lehman,

J . Tjon, B. R o u b e n

A.

Leid man ,

N.

C43,

B.

T.L 19. (19 )

P.C P.

rey M

Phys.

Rouben

and

M.

24

and Phys.

and

Rev.

G.

L. 94

41,

Train ,

and Orlandi ,

T. Rep.

; S.A

Co n

D. Olson, C1 ,

(1975)

Let . Phys.

A127,

Sprung, D. W . (1985)

A.

Rev.

B.R

com unicat on). Rev.

Phys. 189.

158.

McName,

Orlandi , Phys. D. W . and

Univers ta

Gorbun v

Ainsworth, (198)

G.

Phys.

and

(private

(197)

Phil ps Nucl.

J . ucl.N di Laure , Tesi

and

A317, Co n

S.A Berman, D. R . A.C

and

De Tour eil,

Efros:

Phys.

L.

and

W.

Nucl. Phys.

1790;

B.

R.A

di

.L

Sprung,

Trento, Varfolmev,

Phys. Prog.

Bar et , Phys.

29; (1967)

19,

Nucl.

Rev.

Phys.

138;

A24 ,

Nucl.

(19)

78,

Phys.

Rev.

C1,

.1

(1975)

Phys.

564

A273,

W.

and 5104

Rev.

849. 47.

Phys.

Lapi n

Nucl. 54

(198) (1976)

B.H.J.

and Phys.

(197)

A. Let .

C24,

C13,

1207.

Blat Glocke,

B408,

16 .

19;

Rev. Phys.

D. W . E W.

and

Let . (196)

(1984)

C29,

257.

A71,

(19 7).

(1965)

; J.

(1976)

Leid305.

ThisPageIntolyLfBk

ThisPageIntolyLfBk This Page Intentionally Left Blank

Hadron

K.

’

dna Maruym

02

Nuclear and

Elsevir

Physic

H. Scien

with Okuno

B.V

Quasi-deut ron Y.

Hirenzak ,

Physic

yb

eW

have with

model

of

dis ntegration caled Levingr

resvd.

Ume ot

absorpti n

devlop

3He

a henomlgicap 3He

pn

yb

rev woH

and

K.

pairs

ther

phot dis ntegra ion

Universty, and

data

4He

Kume

Women’s

of

exp rimental

.l ew

71

and Nar

reactions

data.

er w

stil

4He

obtained

at

interm diate

selctivy

remain

630-85,

Nar quasi-de t ron yb

the observd.

certain

model

phot n TAGX

Jap n

group

in

The

discrepan

to enrgis whic

data

describ

and contribu ons be

can

betwn

phot dis n-

compared rep oduc

cal u ted

the

from

rea-

result

INTRODUCTION Phot dis ntegration the

few-nuclo

remain inter sted

sthgir

rof

De p a r t m e n t ,

1.

theor ical y exp ct d

lA

Probes

picture

S.

tegration result phot n sonably and

Electromagni (Editors)

to wel-kno

be

yb the

Levingr

in

phot dis ntegra ion Levingr pair

pn

rms radius of p n pair. tum transfer data qualit vely phot nuclear Since be n obtained of 3 H e ( y , evnts into method absorption thes contribu ons data are

and

lactor

[3].

values reactions.

1987, pn)p

[8].

-owt yb

complet y

and eW

section

enabl s

ac ur y

pn

yb

the are

and pairs

later

whic

the

saw

thes

and

updated

trinucleo

exp rimental

Experim ntal

in

are exclusiv

nuclei of

the

selctivy

number

and

to

the

model

obtain

sy tem

whic

reliaby.

saw

studie

using

those esntialy

fo

[4].

phot n rof

the

[5].

They first

absorption

do

evah

time

the observd.

da.t , not

picture.

of

deut ron

rof

studie since belivd

and

twoefcs,

in

the rega din

this

obtained

yb

the Another

any

using

be

contribu ons extra

rep oduc

posible

inter s g

a long

the

a certain t h e relativ nucles. a ediw

relativ pair

light to

mo entu precisly

are

os

the the the of

moen-

nuclei

complet separ te

orde ing only

ekil

of

in

from point

phot -

of

exp rim ntal important

si

eW

data

wavefunctio

range the

stil

the

factor, wavefunctio Recntly,

cur ent

to particles

ther

both naively

induce

quasi-de t ron

of strived the

are structure result .

exprsd

the

time

are

the

a np

reactions kinemat c l y have

for reactions reactions that

using

using rof

They

proces

exp cta ion,

They

target

ielcun

the theor tical

with

result

absorpti n

[6,7].

of

thes

[2].

invest ga d

since I t houlds include

is

data

many Thes

phot dis n egrat o

it

Despite

rof also

works,

rof

theor ical y Miyazm

deut rons informat

that

and

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result and

saw

data rof

have

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det rmin

in quasi-de t ron

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Futami

ind cat g

inter sted

nuclei

exp rim ntal

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nuclei

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light

discrepan.

group

multi-nceo

very

of

us of

TAGX

4He(y,pn)d

cal u ted betwn

efctiv

rof

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be fo

factor, This

The

can

origns [l]

cros

of precisly

el ctromagne ic

discrepan

the

reactions

exp rim ntal y.

rep oduc

sy tem

certain The

and

pions

is

cal u te

that

whole

have data

phot n in

the the

178

final

sta e.

it can To [9,10]. in t al

this

A

data 20 be for denc

whic

result theor tical enrgy ef cts, 4He(y, todis ntegraion data

compared The

section

MeV).

Thus, time,

this for

both

can

in

detail.

the

final ew

150

theor ical y.

reactions

reactions

compared

data observal

[l ]

Their

be

the data

cal u tions

pa er

section

=

at empt

are result nuclear

importan

both nucles,

cal u ted

their

7E Tezuka

pn)dse,tar

cros with

dep n t

and

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it extrmly

theor ical y.

3He(y,pn)p

in

They Since

4He(y,pn)d around yb

think

the consider

to al

angular

we

pairs

for

In

reaction

triplet deviate

result

and

the

rof

directly, ]7[

ind cate MeV.

whic

state

to

to

be understand

with n

the the

the

the with

compared

the si not this

same

data

cros

exist

has

roF

studie

phot n

ther

[lo]. that

can include

simultaneoy.

diferntal

directly.

not

investga

ben

deut ron

section from

This

consi te

has

(i.e include

cros

to

to al the

theor ical y

chan el)

interac o

and

theor ical no

comparisn cros

ben

this

spin

observal

section

and

result

singlet

with are betwn

section investgad

data

has

not

t o know yb configurat s

nucleoi, at

rewol

Wilhem

and in

a ormf data

enrgis

et mesic,

found and

a strong

theor ical y.

whet r

enrgy

data rof igher nergis, but t o the data revo t h e entir inc de t at enuation factor t o acount for specifd as a deut ron. the reactions 3He(y,pn) s ecta or pur ose e w investga both 3He theor ical framewok and try t o eW cal u te al observal ni Our theor ical studies are repo t d

and

that

(Ey

that

theory

the

suitable

5

could

and

are

phot n

distor i n and

the

dep n-

Theor tical

ther

al.

rof

no

4He

rep oduc

phoin

al

forms Ref.

FORMALIS In

this rota Wps )np observal

In

(l),

ind cates exp rimental

yb

b, c ) =

our

model,

expr s

phase

as

in

each

we in

A

final-sta e, In

section

thre -body

writ en

A(a, and

They

region.

2.

wher the vari ble for

understo d

pn

cur ents.

[12]

3He(y, al state be

be

the A(.

in t al

describ

and

suitable

target

y

. . ) si t h e

the

in t al

+

a2 the

+

b2 ew

phot n

square

consider

c2

Kalen

result.

and/or

+

-

pn)dspecta or forms

space

the psectaor

4He(y,

nucles,

flux,

only

The

3He eW

integrate

amplitude

directly

as

with section

and/or

The

quanti y

Since

rof

ew

the

the

and B s cor esp nd

4He, the

model

final-st e

is introduce

to

whic

si

dluow

data,

A(y,pn)B

ew

ekil

evalu t

si t h e

specta or

phase

space

pro e ly

ap lied

to

cal u te the

reaction

to

the

ap ro iately

to

both final-

can

particle

Mandelst m

normalize

in

the

cros

2ac. -

the

cros

hci w defin

- cb2 the

reactions.

compare

dspWta or.

A sy tem. functio ,

phenomlgica to

exactly.

ba2 of

our

deut ron of

(2)

the

chan el

phot n

rof

absorpti n

the

in t al

pn

yb

pair

the

in nucleo

the

nucles

pair,

971

using

the

diferntal

wher

al phenomlgica

l ew

In

picture

I wher

in

of

the

orde

Her

pf

and the

cal u te

describ

sy tem

charge

rep s nt si roughly ew

our model are directly for both entire en rgy phot dis ntegration spectro i target .eH Both t o change the consta factor cros section pn the inglets shown t o b e ap roxim tely section. This evig a minor should lsoa mentio from the begin ,

In

the

square

121

are

(g)

the region

observal

factors overal when

into pair

contribu on contribu on

.VeM

eH

y absorpti n

reaction

in whic

the

target

as

centr-ofmas

rep oduc case,

d(y,p)n

the ew

amplitude

postulate

frame.

yb

the

eH

eW cros

the nucles

esu

section

quasi-de t ron

a

as

12: pn)

particle

l2

phot n.

using

B in t h e

mo entu

to

be

146

s i evalu t d ekil t o describ e w can cal u te He3 and 4He target of inters using reactions. ,rev woH nor the fects efcts are exp ct d normaliz t n each reaction it si necsary. in t h e in t al 50 pb decras t o the her that the since e w evah

region

rof

the

PB

that

p)n

[13],

04 -02

+(PB)pn-B

the

Fermi

evalu t d

=

of

d(y, of

data

7E

t-

the

NUMERICAL

3.

the group

T(ypn absor

estima ed

radi . would

of

1

that

specta or

varibles

~ n )

+ -

(g) section

the

evalu t the

tif enrgy

T(W~

and

B

wide

to

and

ew nucleo

pair form,

wher

kinemat c l

?=I

TA

cros

eH

VeM in

some

II,

any

of

to

nucles,

betwn the

cros

section

ew be

insetv

compa t

of

s and evaw is asumed whic

the 3He

and

exp rim ntal the

rof

labor t y

featur s

relativ

pn

and

frame.

the that

include

informat evaw

presnt

ew

that

pair

205

can

neith r to

the Thus,

model. cal u te

the

rof be

take

specta or

4He

for betwn

from adv nt ges

of

incdet

phot n

the

of

pn

to the the

value

enrgy

two

the

particle

the

observal

tcef

the a Gaus i n

The

compared rega din

the

functio

to

and

VeM

can

t varibles

functio

the rosc section . e w are fre to a par met r t o normalize the absolute In t h e odelm e w d o not include contribu ons state, hci w er w evalu t d in efs.R 9][ a n d a t 7 E = 01 VeM for t h e 3He(y,pn) s ecta or monticaly a s a functio of 7 E a n d phot dis n egrat o reactions a t igher enrgis. final state interac o s i partly include in data of t h e deut ron case. used the tif t o the as

of

case

Mandelst m si the

data

the

in

introduce

to al

from cros

is know the

model

the the

and of

[lo]

of

data in

deut ron deut ron

pair

pn

a

the and to

eW

RESULT 3He(y,

this

section .18-6[

pn) specta or

ew Other

compare numerical

reaction

our result

and

cal u ted

the

are

4He(y, found

to al

cros pn)dspecta or in ef.R

section [12].

reaction

with

exp rim ntal

taken

yb

the

data TAGX

rof

180

phot n experimental data matical [14]. target. se m MeV.

eW

show over

pair large

be results tribution mon t ical y pos e are deuteron

As

to This

total

ew

be in

dif er nc

the for

wil the

cros

observ d can

due

is cor e t d results to

se

in tial lower

be

at

consi tent

total

the

region

Theoretical

np

the

absorption

125 =

with

op osite

the

to 205

phot n those

en rgy, dep n ce

cal u ted

are

by

the 1 as obtained

region.

extrapolation

the

figure,

be whic

en rgi s.

deviate

en rgy

include

the

A excita ion,

could sta e:

fo

Fig.

for

only

from

in

sections

kinematic l

-

with

chan el.

sections

phot n

caused

7E

cros

proces

while

explained

was more

MeV.

In

Howevr, this while

3He

by

evalu ted greatly by

20

en rgies =

dat pf

by

.1

ref. Total

Total

en rgy.

[6]. cros

150 over

taken changi

MeV.

cros The

by

a wide

the by

sections This the

dif er nt

fo

TAGX range

section solid

en rgy wavefunctio

to

fo

curve

group groups

the dep n ce investiga e

the

4He(y, ]7[

and .18 -51[ fo

3He(~,pn)pspectator

indicates

pn)ds ecta or

found

the

region,

a1

the singlet

[9,10]

result

body

the

25

may contribution. the

for

pn

the

becom

section

MeV,

this

fo

pair)

np( en rgy.

cros

unobserv d absorption

including

experimental

I

two

phot n

the in tial at 7E = predict siglet configuration e t a1 [9,10]

the by

dif er nt al

from

fo

dep n ce

data

et

30

peak results

fo

Wilhe m

the

the

two-nucle

the

en rgy the

by

inc de t

the

chan el

the

I

vE

Figure phot n from

integrating contribution

by

theor tical

includ g

fo

show

cal u ted

inclus o from

Wilhe m

100

using

deuteron data the

en rgy the

I

0

by

The

the

by

phot dis ntegration

a functio

pair peak

and

the

theoretical

singlet

values

flat

in tial

pn

a function MeV.

Da t a

model in at fo

shown

kinethe

whic 275

the

to

con-

increas Our

The

or

pair

results

ev n in

the

I

400

(MeV)

the

to

is almost eW hows the pos ib l ty 4He. eW also

have

result

with

reaction

a strong like a ’disconti u y’ t h e cal u ted f o rep oducing multip ed

reaction

as

wer

pf=150

measur d

en rgy

dep ndence result

the

cal u ted

the

at to

in

en rgy

fo

sev ral the Fig.2

lower cros

are

inc de t

phot n

around with dep n ce

taken

en rgy sections

7E varing

18

yb exp rimental

a factor

to

rep oduc

en rgy

h

v

A

the

dep n c .

14

9 .5

0

peak.

eW

I t si difcult

dnif

that rep oduc

to

our

result

the

do observd

not

’discont u y’.

rep oduc

the

20

Figure 2. T o t a l phot n nergy. 20 VeM solid( spectivly. calculated in t h e A en rgy = 02 eV,M 1.67 [7] (solid cir les),

eW

4He ad it on the

eW

-

subtracting 7E the

3He(y,

cal u ted deut ron information

region.

to

for

estimate

40

]51[

data

at

whic

the

2-body

The

(squares),

4He

due

absolute

normaliz t n

to

normalized

MeV,

two-bdy

decay

(dot ed

to

factors

1.8

(cros e ),

the

fo

than

krow cros decay from our

include

cros large

largest

40

are

pf

]71[

reaction

with

and

rep oduc

rof

recnt si s t u d i e

value

may

result

curve),

the

contribut on large

4He(y,pn)dspecta or

cal u ted

and

]61[

section

phot dis n egrat o the

si ven enrgis

rewol

are

her cros

the

VeM

03

=

mentio

to al

the

MeV,

pf

fo

ind cate

30

result

to

the

section lines

curve),

like

contribut ons can older

cros

(open by

in chan els, the

cir les), Efros

the

result

er o s.

rof

the

et

to al.

It

MeV,

are

and

]81[

1191 in have

r~)~He case s i ap roxim tely 05 pb).

our

(w

of

(dashe

10

=

Da t a

al, resonac

they

4He(y, in

a functio VeM

(dash- ot ed

exp rim ntal

pf

giant

section,

section

MeV.

as

01 =

VeM

1.45 40

=

fp

enrgy

peak taken

inc de t curve),

shown

(3-body

for

from

(triangles).

pf refs.

the region.

and

reheigt

1.53

whic

curve),

to al

In

separ tely

4He(y,p)3H.

decay)

yb

1 mb si c o r e t ,

f I this

SUM ARY

4.

eW

would

phot dis ntegration

The

02

In have

this

pn) Specta o,

pa er, invest ga d mechanis

ew result

and with

fo

deut ron

have both to

invest ga d

4He(y, describ

reactions

exp rim ntal phot dis ntegration.

the

pn)dS ecta or using the

phot n

data.

phot dis n egrat o whic

evah a ingles In t h e absorpti n eW aveh

theor ical model,

ben

reactions observd

introduce

amplitude

ew

model have

yb using

and

as umed the

relativ

the

TAGX compared the

group. exp rimental

the evaw

the quasifunc-

at

182

tion space sy tem observa l directly. fit

betw n

to

pn

the

integra ion

to

compare The

the

in

entir final

data

fo

pair

careful y

deuteron

with

and the

en rgy

state

the in region

interac on

specta or

orde

data.

fo

phot dis ntegra ion.

to Using

particle

cal u te

the

inter s si p a r t l y

Our model si found t o rep oduc the descr pan i remain. Thes descr pan i cros section for 3He(y,pn)ta and f o 4He(y,pn)d ta , reaction around are ifcultd t o rep oduce with the pres nt thes discrepan nvolei important fo the phot dis ntegra ion reactions be treated carefuly. orF the 4He target inclus o f o large er o rof some parts roF further studies, ew ned t o devlop functio s fo the in t al and final sta es in orde t o understand thes reactions cal u te the bservalo ni a suitable data. eW would like t o thank the TAGX

and

include gros

-

(i )

7E informat 3He fo

exp rimental

pres nt

featur s

4He

phot n

using

group

target

theor tical compare in

eW and

the

on

the

step-lik

the

rof

that

of change

exp rimenal ew

ew

the

that

can

deuteron based

think it

with

Thus diferncs could

discrepan

but

fo cros

very

on

and

compare

certain

that should

due

to

the evaw

cur ents

important

with

discuon.

REFERENCES

9.

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Phys. Phys.

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10

34

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al

Nuov

87

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60;

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(1970) 71

A.

.N

(1974)l.

Cim.

4015.

the

to al

section betwn

ac ur te to

data

the beliv

be

si

model

cal u te used

ew

hadronic

phase

have

to al

thes

the

co rdinate

data,

the

model

stimulating

the

dep n ce

model.

es ntial

treated

a suitable

since

fo

eW

microsp

model,

exist ng

found

data. interac ion

deply.

the

en rgy change

and in

with

model al

MeV.

eH

the

of

the

(i)

step-lik

and case, a microsp

the observal

can

150

phenomlgica

and more

form

the

are

in

the

639. Gor-

38A

to

Hadron K.

dna Maruym

a 02

Nuclear and

Elsevir

Physic

H. Scien

Two-nucle

lA

Probes

rights

resvd.

der

mechanis at resoluti n

Insti ut Morgenstl

:s erd a

emison

ac el r to

phot n

Univers ta

D-6702 .physik.uni-tuebingen.de

Tubinge ,

Tubinge ,

exp rim nts MAI

absorption. distance

and (7,)

mean en rgy

the

back

than

field revald

[1,2]

05

the

conti u m

creation Thus

one

Pauli

The can

Maim

at Evidenc

si exp rim nts (e,N)

perfomd

Germany

Mainz

are

rof

pres nt d.

with discue.

real

efcts

The

due ned

si emphasi d.

and

eW

to of

nucleoa ombinedc

virtual have

phot ns

studie

the

an lysi

at

reaction

cor elati ns

the

of

hig

INTRODUCTION The

low-m entu ments traced more inter ucl o into repulsion scat ering; the princ le.

of

inter ucl o

der

14,

grabmy@pit

short

.1

in

at

a

Two-nucle cw-eltron

183

exp rim nts

Grabmayr

Physikalce fuA liam-e

two-nucle

B.V

Electromagni (Editors)

emison Pet r

nucleo-

htiw

onukO

princ le

be

dynamic l

observd

to distances

to

years

regim. the

or

cor elati ns

ago, at

the

smal degr

the more

the

conservati

with

poten ial Ther

:p

short

Cdyn

that

sta ed

distance short- ange contributed

this

deviat ons

cor elati ns.

%52 mean-fild

typical

relativ

pro e ti s Fermi

wories

namely,

spoil

wher

describ Only about

that

princ al

observ

to

around

a certain f o a n verag

density

con e t d

conept

range

inter-uclo

from of

centr-ofmu

are

are

in

fo

surface recnt

the

the

alre dy

strength

hig

conept

spectroy

one-particl

of whic

nuclear

si l e w feature the

the

sevral

mean

centr distance :

saw

at

mo entu

kinds

the

time

and

can ot yb

sta es

rep s nt

that know

al

nucleos

dleif

of

of

inter s

survie

misng.

has transfe

birth

they in

shift fre

hci w

triv al

are

and

nucleoin

and

behaviour

and

of

comp ne ts purs ed

be n

the

whic

cor elati ns

Im ediat ly

fo

anymore. atomic

ap rent

the

sup ortive

particular

exp ri-

this shel

strength

the

sucefl low-enrgy,

knocut

are include

in

rather clasi

at hig

The nuclei

saw model

short

strong

(N )

despit

as

the e.g

in

those

so-caled the

up

Pauli due

whic

fre

to

184

(se . tricate. stil H. the tion about culations difernt with type

The

e.g Muther

empir cal yield

bind g difernt

l ehs-f o

Recnt cor elat d

with

for

real

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si

at

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theor tical only

bind g

with

play

The

invest ga on the

point

a cru ial

invest ga on

thes

of

aim

[4,5 9].

the

poten ials

part part

evaw

towards

functio

fo

fo

thes in

cal u tions

two

whic

specif

ranged

bind g.

rof rof ben

tif

on

from

Simple difernt

from

mean

cor elati ns

efcts

in

A

bind g

found.

t h e phase si orlyp rof t h e

nucleos techniqus

based

short

evah

lpl 2

modern

a result @ si deriv

poten ials

into

poten ials. While

is extrac ed

the

ranged

nuclear

N

exchang 7r

the

short cor elati ns

poten ials.

nucleo

rof

Her,

of

N of

realist c

density

nuclei

incorp ated rof

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fo

tensor

ben

treatment

argument using

evitc f

enrgy

contribu ons

behaviour

creation

and

cal u tions =

>

>

/V1

=

two-b dy

given

the

stronge

two-nucle

the

>

$21~1~2

,rev woH

have

the recnt modern

Brueckn-HatFo

np

the

uncor elat d

exp(S)-method

compilat n

nuclear

for

cleary rev woh

from

t o produce

scat ering

two-hle

tensor

[4])

l6O

for

, Q throug : one

at

cal-

ind cates

[4].

ref.

yb calu-

poten ials

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-ni

mediu

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chan el

(ad pted the

of Harte-Fock

ap ro ches si more

nuclear

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shift defin,

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func-

si nevig

[4].

operator

the QllVl

demonstra es

same

The

the

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saturation

the

quality.

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tions The

[4]

cor elati ns

[3]). of

from

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ranged ref.

One

arise

Figure

wher

long

an ih l t o

y=O,

Fig.

The

fm).

>

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rof

two

z,z-plane

operato s cor elat d

the

> >

AQiIVi

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n=2

+SllVl

density

in

to

in

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si left

selctd

the

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set

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of

read

n particle-n

hole

sta es.

>

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prot ns

On

produce evaw

(5) orbit

of

lplp

rof Fig.

O=y

of

wher 1 the

06l

operato

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second

S2=0

particle

and

therfo

si dexif

185

the locati n density the but contribut ons.

two-b dy can

T=O also

of its

one-ucl

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observd

pair con e tra ion

si second

just

particle).

revals

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exp riments.

at

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at

product posit n

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short

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of of

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howevr,

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densit

a learc particle. of s t r e n g t h despit

distance

(ir esp ct v

depl tion Simlar

yb large

TA

Figure perim ntal setup ger, doscpe Pip neutron thgilf- o ray kinemat c l gions cated.

.2 prot n

a factor

tag-

[l ]

AND

VeM

at

relativ

esolc

reactions,

hig

reaction

the

resoluti n

of

as

wen models

(y,np),

VIRTUAL

4

had

reactions.

(y,p ),

PHOT NS

ar-er

at

Mainz

of using

the

PiP/TOF

the

wogsalG iN

group

tag in

are

perfomd

imp nge phot ns

on

at

spectrom

4 pm thin radi tor ro on 0 1 polarised are ne d . The phot n beam si colimated (diamet r of ap rox. 1 , 5 cm) on t h e uclearn targets with n a kapton can or of shet f o graphite ro l i t h u m . t o fre run i g calers with n the tag er ocalf plane surem nts. Typical aluesv of ~ ~ = 4 5 & 2 % evah enb yb a ring fo 1 m thick plastic counters, hci w act as and a s veto det c ors rof neutrons t o b e elctds from

85

rof

two-nucle

of

ind-

[14]

REAL

the

the

about exchang

-oh

Thre

exp riments

WITH

fo

meson

,rev woH

area, and

of

two-b dy

and

time-

are

The

MAINZ

pairs

cal u tions

cor elati ns

induce

the

Ex-

with

[12].

in

This

EXP RIMENTS

2.

MAI

removal

the

si n o t a n adequate to l one has t o invest ga exp rim ntal method rof a n aces towards be n sug e t d alre dy ni t h e 50-ies, ni particular pion and phot n Both probes are understo d t o be absor ed domina tly on nucleo proximty [lo]. Howevr, beam quality, nergy resoluti n and background e.g the not ri us final-st e interaction, revntdp seriou proges. gen ration f o exp rimental techniqu s rof w c ac el r to s and large det c ors on one ides and wen devlopmnts of uclearn structure permit a renwd ap ro ch towards N cor elati ns. The aim of t h e pres nt exp rim ntal seri si a ombinedc an lysi (e, np) and (e, p ) t o exploit the adv nt ges of each of t h e reactions. removal

sA

density

the

pm

thick

hci w yb

the

consit

obtained.

in

The so-caled

start

[15].

TOF[12].

det c ors

phot n The

wc diamon

orde

el ctron

ac el r to

Electron to

eith r

flux

tag in Charged

target rof

be of

charged

ycnei f

crystal liqud

Figure Layout

3. the

thre spectromet r facilty ]31[ Mainz.

at

beams

l ew

defin

is

calibr ted

is

sur o nde particles

in

of case

helium mea-

particles

are

186

exclusivy

det cted deuterons in

by air

by

sel ct d tion azimuthal facil ty so-caled

TOF

by

(Em) The

dead

with

160(e, p )14C [13]

fo

super- a l e

from ap ropriate

direct on

fiveold

pions

the

layers.

an

via

6 VeM

with

the nucleo

The

layerd

the

hig

pulse

heig t

- E technique.

The

neutron

en rgy about

after

Pi [1 ].

relative

thre

observa l mo entum

s i defin

mo enta

OF fo

as

the

4.

12C

en rgy

The and

ranges

fin

(y,np) 4He.

The

pro e

MECHANIS

difernc

importance

betw n

and

fiP:

(PWIA) p , can be interp et d I t governs the gros featur s fo The mis ng en rgy Em = k -T, particles in t h e in- a n d outg in ( A - 2 ) sy tem f o the recoil ng mo entum is efind a s fi? = a handle f o the relative mo entum get

Figure phot n targets

hod sc pe

AE

Prot ns

en rgy

cor e ti n is o b t a i n e d fo 0 . 7 ns. The FWHM cuts on pulse heig t vs. ime-oflght. has be n obtained. The angul r resoluti n can be translated into a mo entum exp riments with virtual phot ns (140 PA). A waterf l beam cur ents kinematics asw sel ct d [17], hicw

aver g

REACTION

3.

&,

and

the

and

is

reaction

compared

fim

the

betw n the

;(Cp

are two

=

as

-Tp

nucleos

incom g

+

the angul r

the

F,). -

for

,p

and

thre

the

In

en rgy,

P fo as

the particular,

that in t al

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hig [8].

pairs

l iw

Acknowledgmt

am inter s .

I ouldw indebt

ekil

to

to

acknowledg al

me b rs

of

the

usefl

discuon

PiP/TOF

with

group

rof

the

J.

Ryckebush

strong

and

sup ort

.H of

Muther. our

I comn

REF NCES .1 2. 3. 4.

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Erice, in

1; private

293

subatomic

19 ,

Prog. physic ,

com .

Part. ed.

nordaH K.

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cur ents[6]. the complet n s ,

(GeV/~)~[21, data rest ic as 0 . 2 fm,

meson-xchag

the

N

elctri 2.8

smal

and

mo entu - ra sfe , Ll~l(~O1)

of by

thre

the

to Thes

Foreign

(D.O.E.)

symdata.

deut ron,

are

elas-

q.

The thre

l iw Vis ting

be under

194

compared model

THE

2.

smal , to ic clustering trem s and tion have smal

with

that

N

the

rep s nt

scat ering

al

R-MAT IX

At

hig fre dom). ther fo e in For

permit ing into

whic

their at

the

colr

be n

wave QCD

the

and

data.

f de

data.

BOUNDARY mo entum-transfer

has

the

two

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At shown

over

transit on

functio s ap lication,

regions,

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to

a short

each con e t d

thes

CONDIT ON

mo entum-transfer

singlet

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hadrons

oc ur distance.

range)

over

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l ew in

boundary,

whic

confi em t

the

can

extrapolate

to a

MODEL the in t e r m s (long

(confi em nt). a smal

one

run ing

R-matrix

a boundary

fo

and

fo

gluons efcts

betw n

coupling

is lew ap roximate at t h e quark

the R-matrix

the

constant

quarks

transit on run ing

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method[8] a dif er nt condit on

requi s

form

no perturbative

The

fo

by

suitable

f o cur ent

range)

range

coupling

t o this Hamiltonian,

separ ting wave

equation

thes

constant[7],

suited functio

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QCD

is exsitua-

surface.

to

is[4,5]

be

with

i n whic the poles residu the boundaries. residu .

go pk

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W,

is t h e are are residu

the given Thus

exterior

wave

en rgi s can

wher t h e fractional parentage f o Clebsch-Gord n coefints ration. Ther fore only at inf ty, are the pole The hadrons at r > hadron mas e and coupling condit ons. The separ tion radius, fo the equil br um radius the derivat es a t T O fo TO, W%(TO)) = 0 . Using with some precis on, giv n model, but not orf the domain. The Cloudy bag detailed tif t o N data

by

the

be

functio

fo

absolute fap(W)

expr s d

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the MIT for

interact

ro

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r0, the model TLab

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rep s nti g

ti

spin/flavor/c lor

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exchang

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functio . data,

ro

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with ruling =

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fo

1.05

Eq. lat er out

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first fm.

is consi ten

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lat er

the

distant

model

given

fixes for with

derivat es

TO,

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fo

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in poles by

or

fre dom

sen it v y

requi s

total

quark

as

fo

at

poles

experiments

fo

becaus

is t h e

the

potentials, range

a, W vanish g functio

with

constant

indep nt

the

model)

evaw

coefints

space efctiv

by

sta es

functio s

geom tric the

with n evaw

chan el

internal

are

hadron fixed

be

inter o wol

bag

set

as

via

must

the internal

mero phic

the

constants

a value

squares

are

coefints the fre

for

a complet

for then some

the

the

the

multi-hadron gives

evid nc

value

at

terms and know

TO

Cloudy

the

configu-

sym etry fo

that

en rgy,

(5

p& satisfy

0.85 fo

a go d

to TO

bag for

591

the near qij

tsewol

the

and

q3

f-poles

I =

1 exotic at

configurat s.

DE U T E R O N

3. 3.1.

Interior

The

Becaus

each

In

other

first

(3S1)

evaw

f-pole

I = and of their

with

resona c , The

to

tsewol

0+[10]

at

=

JP

whic chan els

includes

whic

0. 3

core

par met rs

discont u

multi-q ark in

N

the

07.2

sy tem

configurats

the

to

wol

1

thres old

the

f-pole width

the

NS1(650)P

GeV.

Thes

si t h e

1 = 0, P J

in

the

ben

si

the fo

residu .

fo best

exotics.

for

the and

The

than

exchang

of

resona c ,

other

models

f$

rev woH

+1

=

produce

the

at

types large

are

with to

rof

the

include

edf

ap rent

at

rg,

in

min al

2.63

GeV.

core

f&

are

sharply

rest ic ed

yb

fit ng

core

are

thres old

include

of

embodi

efct.

sta es l ew

the

al But

some

whic

are

configurat ,

has importance in

revo

coupling

only

N

is fre

in

in

thres old,

the

and

the

deut ron

becaus

enrgy work.

fap,

same

The

the have

v(~D~) A

and

the adjust

N

but

6 and

the

to

A (3D1)

models.

N

to

com-

f-matrix.

recnt

sector sector .

ratio

coupled

a wol

v(~S~),

is

inter o

the

our

chan els,

arise

si

the

our

quark

ther

exp rim ntal rev woH

as

the the

in

deut ron

W,

models

the

exotic

that

being

a sub tan i l

also

deut ron.

the

the

si lsoa repulsion enrgy

as

[q(lsa)l6

of in

that

in

si i n of

and

the

so

coupling,

also rewol

of

hole

(3D1)

chan el are

repulsiv

N

the the

at

q .f de

poten ials

configurat , width shown[l ]

the

be n

proba il ty

a argel of t h e this

of

tensor

has

resulting

and

chanels

It

As

the N scat ering data, a tif t o t h e np(3S1 -3 Dl) phase par met rs 6 and sector requi s and 1 rof 5 0 . 8 GeV. roF the odelsm C and 0 [12], hci w evah chan els. t h e rewol nergy behavior of t h e s6 and 1 det rmin the the enrgy dep n c rof 0.4 GeV < ,& < 0.8 VeG sexif those LIA(~S~) sectors, and the N t o t h e sum of A ( 3 D 1 ) and A(D1) two evah the same thres old behavior, fectinga the elastic scat ering os t h e ratio Only detail d A-production data could separ te them, edf . The magnetic form factor -depncq si very senitv to the op site spin and conveti cur ents of thes sta es[6]. The

than

[q(ls;)I6

actu l model

)1S3(

k[

AS31( 620) P

imples

both

rof

and

N *(14 0) 3S

the

cores

functio s

yb

strong

other

consta .

a pro e ty In our at T O .

the

evaw

N meson

importance and

thre

functio s,

the mas.

This

enrgis

importan

ecioh

deut ron.

of

yb

next

f , and

d.0 f evaw

produce

novaishg

deut ron

as

large

mas most

nearly

ext rio

be

the

noted

scat ering.

efctiv

to

are

consta

5 0.004[6].

increas

have first

the

rof

sy tem,

chan els are

states

modify

and

can scat ering

=

isobar

N

times

function PJ

be

of

N

above fa@

to

2-3

evaw

corespndig GeV

the

in

si

TO

sy tem,

long

higer

chan els

large

has

inter o

a resonac.

EN 0.76

GeV, vanishe

hard change

the

comp ne ts

De t e r m i n g

state,

estima ed

0,

to

its

function the in

+1

ALI(~S~)

and

contribut ng and range NS1 (153 )(lp ), Thes neglib 3.3.

Exterior the

A (3D1)

and

cor esp nd

PREDICTIONS

the I = 0, J P = resonac si only inter o evaw functio inter o has be n evaw function, in t h e fectiv from the rapid matching fo proba il ty and The fact that pensated yb t h e efctiv range models difer at 3.2.

W,

while

N

of

to

.yaw

and last the the

691

The

ecioh

=

TO

to

fo

1.05

the

model

separ tion mf

s6

C

di

as while

case

not

radius

discue

consider

quark

saw

above.

ro

=

As

D si a b e t e r

0.74 shown

tif

fm. to

configurat s[l3]. previously[ 2],

5

seif

&

4.-10

g

-30

cause

duces

3.4. ativ stic, (MEC) roF netic Both used. and nucleo predict ons

C, ap roximat on MEC[16, 7]. saw

EDF

The previous In

terms

the

form- act s. Hohler to

er H

The

D and guide

B(q2) el ctri

ew

of

er w

chan el ,7i

the

isobar

et

result

predict ons

work[l2],

coupled

IA

pres nt, E wher roF

form-act

and the

the and

p,

In

]41[. a rof

yb

250 0

ledoM phase g uB

the

al

(Figs.

6-3

versu

C

the

and choie.

second and

the

first

E

the

Gari-K impel an [l5] [12])

of

and

with the

rof tpair

factors

case

(HO)

GK

consi te

model

w,

form

the

ext nd

orde

D model

equivalnt

with

best fits

the

other its

the

large

This

tif

chanels width,

dep n c

inelastcy. requid

(Fig.

s j7

isobar N *(14 0),

the

1).

model

coupling

in-

to

E result

51,6(3D1)

to

and

This

bemodi-

the

re-

and

to

.1

Jp E (solid

0, =

19 -0 91

(squares).

The

phase

par met rs np

1+, curves);

=

par met rs

SAID

(dashed

phase

for

scat ering.

SPOO curwes);

par met rs

(MeV)

f de impulse

O

750

50

TL

enrgy

a bet er

I

0 92

750

of

chanels.

Figure

2

0 94

50

the

f-pole

100

096

(MeV)

D evig

f-poles

tsewol

v

0 98

T,

the

the creas

in the a

B

-20

250

and

include ,

AA

0

0

When

are 3-

0 90

C

the

1.

I

12.5

Without

D include Model

ratio

orde

the

B(q2)

MEC

C models

ap roxim t n cor e ti ns are

This

yb very

relativ s c fo

relativ s c ratios.

(IA)

and asumed

are

and pro ti nal

cor e ti ns sen

si wol

not

the data

AA(7D1)

incoste

and

the

be

the

of

has

to

coretins not

the

nucleo

to result

has

A(q2) edf, have

be n

t o irstf the ucleon chan els

A(q2)

si

form- act . the

ben

L ~ A ( ~ D ~ ) coupling yet

with meson-xchag

to

as

magnetic range

cal u ted

the

isobar

(GK)

a god

nucleo

coretin

term

pry

to

to

q exp rim ntal

It

D er w

optim zed

avilbe ad e be n

the

for

relativ s c are form

the

dominated

el ctromag-

to

include

to to

orde .

HO

the the

norel-

neglctd.

factors

at

result

cur ent

yb

The

er w

ecioh

the

t20(q2)

fo

N

the impulse the

time. models in sector

the data.

197

10-4

0.5

0.0

-1.0

10-8

25

oslA

magnetic models

c

-1.5

the

bal nce

Table

50

of

mo ent,

1 hows and

C

75

q2

A unkow

the D the

10

(fermi- )

125

and result

from

result

N *(14 0) of

model

are

-2.0

150

coupling

indep t as

E

sta ed

rof

[12] in

to

data,

the

1

excpt

2

N have

sta ic

3

and pro e ti s

not

ben

rof

4 q

the

5

(fermi- )

value of

a smal

6

7

of varied. relativ s c

N*(14 0)

the

the

deut ron.

roF change

in

Qdeut.

Table

1

Sta ic Model

e

~p The

factors large with large tiv y

deut ron BE(MeV)

E hig er

the

q2

fits

si

shown

HO

enough. to

the

when

the

shown

ecioh

E Model

PD(%) 5.21 chan els

choie si

of

2. 247 2. 246 mas

A(q2)

t20(q2)

pro e ti s

data the

pA5(%)

have

in GK in

fo

neglib

2.

Fig. reason bly

<

q2

Fig. nucleo

3.

si

l ew

sen

si made. 2.5 (GeV/c2), roF

PA,(%)

3.24

PN*(%)~ 1.79

&(fm2)

0.71

PD(PL?) 360 .857

.273 .286

proba il ty.

It

ecioh

for

PAS(%)

.0 6

form- act s,

the

that

rof

Models mo entu

q2

model

< 2.5 but

at sa

thes

C

(GeV/c)2,

E

with and

6 (GeV/c2) transfe canel

eith r

D on range

ecioh si nlyo the other only model

but

in

the

ther

ratio

of

large

nucleo hand

enough

C

si eglibn of quadr pole

with

formare

bet er GK

rof

seni-

si to

198

mon p le the range This with and smal er (q2

fo q. is r e l a t e d intermediate D. B(q2) The =

q.

1.3

used.

Model

simple

D puts the large AA comp ne ts,

to for

rev woH

(GeV/c) .

amplitudes

The

models

the

the

min um

constant

whic

dominates maxi um

amplitude

C

tzo.

f-matrix

fo

ofthe

has

model,

t2o

the

at

2,

=

maxi um

D si simlar fo B(q2)

and

L

The

to for

result

,C

much

to

A

is owevrh a go d

smal

sta es

fo

E

fo

in

betw n

t2o

that

model

gives

is

[12]

with

at

very

tif

a mo entum this model. that

min ma much

sen it v over

the

fo

to

models

Model

transfer.

E, C

at

smal

to whole

slight y a aluev

CONCLUSIONS

4.

very

el ctri

model

The

duces not has for varied.

to

E,

t h e rel vant isobar T L ~ 5 ~ 0.8 GeV. It l ew sta ic fo the deut ron and A(q2) f o r q 2 <_ 6 ( G e V / c ) 2 . tif t Z O ( q 2 ) a s l ew as t h e simpler model C (although i t is b e t e r than the first min um fo B ( q 2 ) at much to smal a value. To cor e t the B(q2), the ratio of t h e AA(701) to A (3D1) couplings to the NN sector a further substi ution f o N*(14 0) coupling for That, and perhaps the N sector may also cor e t the fit t o t h e maxi u fo t 2 0 ( q 2 ) . the

R-matrix

boundary

np(3S1 the

&) pro e ti s

-3

condit on

scat ering

model

phase

l ew

with

up

to

al

chan els, also

rep o-

rep oduces

I t does D), a n d ful model (E) ne ds to be AA coupling

model

REF NCES

3.

.1 2.

4. 5.

6. 7. 8. 9.

10. .1 12. 13. 14. 15. 16.

17.

L.C R.G D. A b o t . P LaFr nce .P G o n z d e z , W.P M. Creutz, E.P P. L a F r n c e , J . Bal H . Feshbac P.G E.L G . Hohler, M . Gari P.G. used H . Arenhov l, includes

Alexa

et

Arnold

et

.P

Phys.

Wigner et

and

Blunden,

Blunden, her .

bo st

E.

and

W.

E.L

Phys. arXive:nucl- x/0 1 6,

Phys.

Let .

H.

Feshbac ,

Krumpelman ,

private

F.

cor e tions

Let .

Eisenbud, Lomn

E.L

Piertarine

and

Blunde

Rev.

Let .

Rev.

Lom n,

L.

W.R.

Rev.

Phys.

E.L

LaFr nce

P.G

and

al.,

and

al.,

al., and

Sitarski,

Lom n

al.,

et

Gre nb rg

023

Lom n,

and

(19 4)

and

M.

Phys. An .

(1980)

not

T.

include

Wilbo s,

(1987)

Rev. Lom n, Rev.

Aw, and

(19 )

85 Lom n,

E.L

An . I . Sab -Stefan scu, Phys.

and com unicat on.

Ritz

Phys. E.L

and

54

82

Let .

Phys. E.L Phys.

.602

1374, and

31.

refncs

D34 Phys.

Lom n,

to

(NY)

48 B173

D35

Rev.

(1964)

Phys. (1986)

be

ther in. refncs (1987) C36

ther in. 214.

(1987)

2479.

29. 92

the

ther in. 134.

Rev.

(NY)

formulas

refncs

and

(1947)

Let . The in

(1986) Phys.

27

nucl-th/9306 2 .

and 1723,

work

published

Nucl.

19.

Rev.

(1968)

of

fo

Blunde P.G

Phys. 10.

C40

94.

(198 )

154.

B14

(1976) and

Phys.

Blunde

50.

Ian Rev.

and

Towner C.

are This

I. Towner.

work

VI.

NUCLEON

HIGH-ENERGY

STRUCTURE

EL CTRONS

STUDIED

BY

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32

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the

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sections

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a *y

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215

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FZ*(W2, The measur d hold. no test and ned the the studies

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a2r74 =

are

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62

toge h r

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rof

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[30]

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factoriz n measur nt

;F

> 4 GeV2,

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from si exp ct d of . Z F i t si dif cult QCD leading Cleary ther virtual

be

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l ew

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216 t " " "

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I i

t f

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/

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05 0 25 0

rof 1

0 75

in

the

are the obtained Gribov The hig er line par met rization.

05 0 25 0

1 0 75

05 0 25

0 1

0 75 05

26.

functio , fixed

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figure.

direct

values

open factorizat on ful

orde

is

strucas

The

measurem nts, triangles

from

phot n functio

as

;F

line

that

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the

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tif

indicated

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result

dashed

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tion. decr asing directly the

I=-

-

DISCU ION

6.

eW

Let

eW

con lude saw

that x.

related

exchanged

1 x,m2

us

in

discu Wher

%

phot n

-.

in

the case

to

the

THE last

this are

OF

STRUCT RE

fo space

point

is given

section the

the

prot n co rdinate

that

more

clear y.

partons by

at at

located?

[6],

THE

wol

x one

wol

the

x,

fo

INTERACTION

the

studies density

In

parton.

the

The

fo

prot n

the distance

fo partons

rest

increas

frame, 1 in

the

the Bjorken

interacwith :3

fo

direct on

is

0.lfm X

Ther fore

partons with x >0.1 are x <0.1 have no direct relation t o the the properties of t h e y*p interaction. a y*p interaction woH can ew describe virtual phot n fluctuates into a qtj fi the interaction is ’ s o f t ’ or ’ h a r d ’ configuration i n whic the phot n hard nature f o t h e interaction si o b t a i n a sym etric q t j pair with large .Tk the asym etric configuration si d o m i n a t compone t whic interacts with the physic . The sym etric comp ne t scre n d by colr transparency (CT). configuration gets big er. Each one space for such configurations increas .

in

pair

[32]. fluctuates

the

structure

inter o

and

The

at then

wol soft into

fo

the of

the

x? proces an

prot n.

the

prot n, It

configuration

The

wol

oc urs

in is t h e

result

while

al

partons

x partons

fo

two

this

fo

steps: pair

ICT

a large

with

describe first

det rmines

spatial

The a smal configuration fo The two configurat s i n figure 27. At Q 2 = 0 and the large colr orcesf produce a hadronic prot n and leads t o hadronic no -perturbative soft contributes eryv lit le; the hig ICT configuration si At hig er Q2 the contribution f o the sym etric smal stil contributes lit le becaus fo CT, but the phase Nev rth l s , the asym etric large configuration when

the

fluct a ion

asym etric

is i n t o a r e shown

smal

qtj

pair.

the

712

p-remnat

Figure a qtj configuration, configuration.

is way while

also

in

stil

to

picture loks

27.

pair

in

proces .

fo

the

se slow

the

Fluctuation

(a)

an

(b)

contributing this DIS,

y*p

the

phot n

smal

a sym etric

and

interplay

the quark

fo

asym etric

fast

interacts

frame

is

quark

thus

yb

just

into

ICT

large

soft the

with the

like

Figure the into quark

both

lo king

from

curent kT

asym etric

the

O=zQ

at

and

the prot n

point

This

an

A of

asym etric

becom s

hard

diagram

case.

28.

DIS view

diagram,

fo

the comp ne ts

in

configurat a ofts brings

in

jet

cur ent

figure proces .

pair,

becom s

the

as

a phot n

in

are 28.

whic jet. pres nt.

In

se n

from the

fast

Another a simple QPM the cur ent jet the DIS proces f o soft and hard

Thus

interplay

fluctuating

CONCLUSION

7.

0

In

DIS

In

orde

z hig

at

exp riments to

I ouldw and livey for being H. Abramowicz

like wonderful

to

Symposium.

study

region.

Q2

the

thank

Profes host helpfu for

inter o

This

Special

wol

during

z one

wil

be

studies

structure

K.

thanks

Maruyam

my

discu on .

of

at

done

are

vis t

due

in

HERA

Jap n.

the

’structure’

the

prot n,

to

and

fo after

the

H.

Profes

one

hig

Okuno

Final y

I would

K.

the ne ds

luminos ty

Tokush

interac ion.

p’y

for

to

measur

organiz like

the

upgrade.

and

t o thank

hig

a pleas nt his group Profes

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Thorne,

(197)

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9-038,

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et

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et a l . et al.

, DESY-9056,

using in

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by

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J . C3(19 8)

Phys.

Phys. Phys.

with

to

wM

.1

J. J.

J. Finla d.

107.

.7642

t-quark, solid

GeV.

star

sen it v y

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from

AMz)

AMH,

x2.

the

SM

the

contribu on

(AM, (PDF);::::

the

yb

namely

nwohs

, DESY-905,

, DESY-9107,

that

-VeG

obtained

REFERENCES 1.

First,

as

GeV. above)

saw

as umptions.

yb

GeV, double

(theo.)

the

theor tical extrac ed yield

GeVf3.7(theo.)

H1 a Standard

The

The MS obtained

the

=

and bosn

2

muon-decay

shown

wM 80.9zk3.3(stat.)i1.7(syst.) MS

perfomd of

81.4T$:i(sta =

H1

line.

The tions

er w

Finla d. Finla d.

saw

the

Hadron

K.

and Maruym

02

on

Scien

with Okuno

B.V

Sakemi"* of

the of

positr n and

asym etri on

1 GeV2 z rof up

polariz t on with hadron GeV/c typical arise

zero.

charged

pairs

the measur d

,

from

lA

Probes

sthgir

29 resvd.

nucleo

studie

SEMR H by

col ab r ti n

Physic ,

Toky Meguro-k, of

hadrons

polarized

and

Electromagni

HERM S

1 Ookay m ,

Spin

(Editors)

the

fo

behalf

negativly

sci yhP H.

structure

"Departmen - 2 12-

of

and

Elsevir

Spin Yasuhiro

Nuclear

semi-ncluv

< 10

< Q2

down si negativ A measur nt si lsoa measur d

in

de p gluon

the

The measur d of

asym etry polariz t n.

of

5 8-2 1 cros

be n

and

. Polarized

GeV2 in

pres nt d.

a positve

have

hydrogen quarks.

Insti ute

oyk T

3He

roF

si

inelastc

h+-

range.

distr butions

polariz t n

asym etr

dep-inlastc in

rof

from

with

contras

producti n

kinemat c polariz t n

in

the

the

The

pairs

negativ ,

scat ering

in

targets quark

quark spin

Japan

,1

section

measur d

up

the

Technolgy,

are

s i positve in

lkp

the

>

prot ns,

extrac ed

of

1.5

to

and

the GeV/c

the

of

0.23

of

phot r duction

positvely

scat ering range

can

and

down si compatible and

positve

< x < 0.6

as

the

sea

be

a functio fo

asym etri

interp ted

and

polarized

pk2

quark hig-pT

>

1.0

to

INTRODUCTION

.1

polarized the

The

HERM S

de p

nucleo

exp rim nt

inelast c may

be

studies

scat ering decomps

the (DIS). as:

spin In

the

structure

the

fo

Quark-Parton

nucleo

using Model

semi-ncluv

(QPM),

the

spin

of

wher

)1(

and and Ax whic

Previous

distr bution

*E-mail

AX, gluon

orbital

betw n

Au, =

AG,

,q L

valenc

inclusve

can

ad res :

be

and

+

+Ad,

functio s

interp ted

pj.ca.hceti .syhp.lcun@imekas

LZG mo entu . sea

and

angul r

+

Au, exp rim nts (PDFs)

are

the

XA

contribu s: Ai +

in

contribu s

+ Ad,

the

precisly

Aq

can

QPM

Ad+ as

E

(qf(z)

be

measurd

As the -

sum

q-(z)):

from

furthe

+

dive

quark

and

among

gluon

spin

the

quark

and

quark flavors,

Ag.

revo

the

polarized

(2)

al

the

flavors

structure of

polarized

functio

parton

g1

(x),

032

The (anti-par l el) charge. scat er d and

function, Her , en rgy

)z(1g

from

a third fo In t h e scat er d virtual phot n final state. the ind v ual det cts the whic are One yaw fusion diagram. dijet production. the cent r PT hadrons dep ndent gluon distribution This pa er the HERMES in t h e HERA from the

THE

2.

27.5

qf(-), rep s nt t o the nucleo z is t h e Bjorken lepton’s kinematics, f o the exchang d various targets the nucleo spin, semi-ncluv measur ments, lepton. Hadron yb a point-l ke Measuring asym etri s contribu ons properties f o the cor elat d t o the t o measur AG(x) In de p Jet separ tion f o mas en rgy instead f o jets. hig-pr hadron AG have reports on t h e exp riment storage ring spin asym etry

[4].

The

HERM S The

HERMES GeV

is n a t u r a l y sion f o synchrot n point si provide during the % (3.4 %) The HERA contai ng metas bil ty-exchange certainty sextupole Breit-Rabi run. The HERMES ing chambers

exp riment

the

spin, virtual

and

and productions

integra ing

that

of

not phot r duction

in

fo

the

yb

DESY,

hig -pT

DIS

the

flavors

hig

fo

27.5 hadrons.

and

sub eq nt

one

quark fo

the

at

enough.

GeV

polarized on

[ l ] [2] 3 .

can

breakup in most

quark polarized

fragmenta ion

the

rev woH

do studies

of

yields reaction.

this fixed

orde

the further the

via

charm

distribution gluon

distribution

yB

AX

polarized.

coin de

thes

after

four-m entum

reactions,

par l e

el m ntary

is only

by

the

measuring

about with

absorption into

ins ght

QCD

phot n production

gluon to

due

use

t o the

from polarized

a

into also

one

scat ering,

the

fo

a hadronic

in t al

target exp riments i t is pos ible f o the sen it v y

el ctrop duction

longitud nal y

in

spin

the

mas .

that with

In leading

squared

found

negativ ly

AX.

low-Q2

beam the

nucleo

q with units fo is d e t r m i n e d

in

whic

negativ

reactions

to nucleo

and

the

charge

Q2/2Mv

flavor of

M is t h e i t has be n sea ems are measur d are describ

5,

posible

condu te the

v are and

the

struck

isolat n

phenom l gica

hadrons

quarks

z =

strange

semi-ncluv

quark

scat ering, is not

be n extraction at

of

in of

being wef A

and revo

and

fo quark

si t h e

the

the is

,e

vari ble

Q2 phot n,

inelastic

using

and

scaling

quark fragments

flavor

wher

distribution

polarized

data

positr ns extracted

hig-

fo

or to spin-

taken

yb

EXPERIMENT exp riment

saw design t o optim ze semi-ncluv DIS measur ments is located a t the DESY laboratory in H a m b u r g , Germany, positron ( o r el ctron) beam si cir ulated in t h e HERA ring. The positr n polarized transver t o the beam direct on due t o a n asym etry radiation, and longitud nal polariz t on at t h e HERMES by a pair of m a t c h e d spin rota ors. The aver g d beam run si 5 % w i t h a relativ sy tema ic uncertain y in t h e measur ment for t h e 3He(H) data. beam pas e through the cent r f o a 40 cm long cylindr a polarized 3He or ’H. I n 19 5, the 3He target atoms becam polarized a fractional optical pum ing [5]. Polariz t on si 46 % with and 19 7, a n Atomic Beam Source (ABS) used f o 5 % . I n 196 magnets and radio-f equ ncy units t o selct desir hyperfin sta es polarimet r (BRP) monit rs t h e prot n polariz t on, whic is 86 % placed

det ctor

befor

is

and

an

after

open-g m try

a dipole

magnet

forwa d

det rmine

spectromet r.

mo enta

A

seri

and

wher in polariz t on

the

interac ion

a

beam emis-

4.0 of

storage

cel

through permane t

fo

during direct ons

fo

un-

’H.

the track-

A

23

of

those Preshow

particles.

from menta polarized data

hadrons.

of

ROVALF

In

Under directly to

wher

and negativ actions Inclusive and sati fy ng The and able.

in

tion

signfcat

The

rep s nt

H’

to

Cernkov 3.8

si

study

thres old

and

an

GeV/c used

the

Cernkov

Electromagn ic to

gluon

furthe

in

extrac polariz t n,

det c or,

195

provides

and

polarized

par l e

Spin

asym etri and

as umption

relat d

structure

D. .y

structure

hadrons

HERM S from the

W2

an lyzed

measur d 195,

kinemat c

and

hadronic

are

and

Interp a ion

yield

the

measur d and

asym etri the

Q2

proba il ty

dep n c .

state

sel ct

target

QPM

196,

requi m nts

fluct a ion

are

ratio,

selctd

asym etri

on

197

the

evnts

the

as umed that

helicty

The

run i g. from

W2

the

nucleo

the

the

inclusve

er w

hadron ni

asym etri .

fo

si

factors. both pions

mas ,

polariz t n

of

gl(z)/Fl(z):

and

A cut

under

probes

g2(z)

includes identf

data semi-ncluv

of the asym etry

functio

that

asym etry

> 10 G e V 2 . > 0.1, lsoa zf

beam

thes

the

q are

functio has

DIS final

to

and

scat ering,

orienta s

as umption

195

measur nt

2.2

evnts

of

one

roF (h+.

are

a struck

be

Q2

indep t quark

above

the

the

polarized

. The fraction, from domina t

factoriz n, of

uncertai s,

functio s

q fragments

the

index

and

a

el ctrons

-om 3He

H’

target

and

asym etry

beam

asym etry nucleo,

:

liA

Al(x),

h of coindet

lA

spin

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asym etry positve

si

and

and

T-).

and on

2.3 x

the

semi-ncluv

Q2

sezi

of

lo6

having

> 1 GeV2, for

the

3He

a det c d

z > 0.2,

cur ent

uncertai s

contribu ons

the

Detec or,

DISTRI-

in

data asym etri

cuts

of

particle polarized

lepton

double-spin

and

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the

of

pions

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spin

discuon,

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a sub ample enrgy

fragments

of from

Radi t on

separ tion

QUARK

phot abs r ion

positr n inclusve

lo6

x

and

section

T+,

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> 4 GeV2

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measur d

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data

constru nucleo

this

asym etri

to

cros

can

the

virtual

wol a

POLARIZED

the

zero,

form

The

THE

semi-ncluv

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identfcao

polariz t ns, respctivly.

FO

de p-in last c anti-p r l e

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Calorimet

.7-69 1

quark

DECOMPSIT N

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In

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BUTIONS

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exp rimental uncertain y 3.2.

5.6

si used

3. 3.1.

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parton

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the

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se

exp rim ntal Dq h ( z ) are into a hadron

are

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y =

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charged

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indep t

sample

uncertain es in

sy tema ic

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phot abs r -

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h-

Figure

respctivly.

the

the

and

v/E

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to

that

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wohs

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no

232

8.0 0.6 0.4 2.0 0

3.0 2.0 0.1

0 -0.1

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Figure .1 Results for the virtual phot n asym etri s 197 data. The top owr hows the asym etri s on the 3He target. The columns are the inclus ve, semi- nclu ve asym etries from left t o right. The inclus ve asym etri s El43 6][ a n d El54 7][ m e a s u r e m n t s . orF the semi- nclu ve a comparison with the SMC 8][ r e s u l t s a r e shown.

the

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yb

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the

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the

the

can

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to

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distr bu ions

Aph-,

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with

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234

extrac ion dep n c be n Within thoug area butions quoted sulting to dict ons HERM S

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Analysi

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section

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ident fy

0.51

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points.

wol

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[15].

are

predict

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ions

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HADRON

PAIRS

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exp rim nts

det rmined

orde

SU(3)

thes

Au,

are

The

yb betwn

both

measur nt , the .1

fourth

chosen to

x range previous

Table

to al

0.57

definto model

diferncs

result senitv

in

cor e t d

the

slight

the

fits

-0. 3

inter st, i

the than

HERMS

si orem measurd

si nevig

of have

in

the

the from

PHOT PRODUCTION

direct on.

weightd

data

uncertai y

THE

spin

to

x-wol

lA

to

comparisn

in

of

asym etry

si t h e number the beam the lat er being spin state. t h e hadron pairs one negativ er w requi d great than saw requi d pions) be great difractve proces, from lepto r duction b e observd l A si shown of t h e

roF

f 0. 3 f 0. 5 f 0. 4

0.6

that slighty

uncertain es,

rof

smaler

to

each at

axis.

The

to

insetv prot n

IN

cros

N+

oT

distr butions

Note difers

are

sy tema ic

ASYM ETRY

The

(anti-par l e )

-0.2 -0. 1

As

:1

SPIN

HERM S

quark

measur d

Ai

+

result

and

si q u o t e d ni t h e measur d romf Refrnc be n extrac ed are slighty

Table. 4.

the

the

exp rim nt.

polariz t n

value

values

Au Ad AS

SMC sea

that

sta i cal hig

Moments

the of

luminoste

product saw

observd

when of requid

observd

great

mas

Tp the x

. A negativ

This

si efind of t h e

decays 0 , ti s a w

I t should

the ni

the

ylevitc f

the

rof beam

that

spectrome r.

than

owt

hadron

be

not asym etry

of

spin

targe

and

4.5

one resp ct reduc

positve

GeV/c

to

sy tem

the meson.

requid that

that si

smal

si

spin

target

least

with vector

noted

at

targe each

and

polariz t n

Each (as uming

background

observd

the and

In

are hadron

fo

transve

the

parle

sta e

thes

positr n

scat er d

the

orde

positve

to at

hig

235 9 1

4

3

0.3

;4 0.25

0.2

6’

o.20 4

0.15

0 0.1

-4 .......

. 4.1

0.5

0

..................... ~.

t 0.2

...................

.

_.I

:.

...........

xAdv _-c

1

4.0-

1.0-

+&-). ........

,

-0.15 -0.2 -0.25

30.0

-0.1

0.5 0.1

30.0

X

Figure rof z(Ad zations points rof

vector

of have

the

for 4.2.

and

+

asym etri a difernt

=<

2.

Ad), world

are

exp cted

meson

Polarized down

comparis n.

Interp eta ion

The

phot n (QCDC) has ben measur d

All

se c

up

result

compared

exp ct d

and

evalu t d

phot n

domina ce

asym etry

D > (AVMD~VMD

for

asym etry

are

model to

the

zero

to

in

be

+

)GA The

=

DIS the

smal .

the

+

gniwol f

2.5

GeV2

data ben

polarized

The

(PGF).

AQCDC~QCDC

interp ted (VMD) t h e owt :yaw

asym etri

Figure ton up x(Aq,) exp rim nt.

comparis n.

LO

The

+

contribu

The

the QCD

APGF~PGF)

The

extrapol ted

a odelm direct of

targe

thes

x(Ld,) SMC

Q2

to

proces

the

proces. de p-in last c

5.2

and

2.5 =

difractve

QCD

points

parquarks SMC

relat d

rof

pro-

ind cat o

direct scat ering

rof

have

GeV2

The

Compt n are

of the

an

contribu ons

X

GeV2

sea

from

data

that si t h u s

includg from

=

result

and

phot n proces:

to

separ tion

Q2

at

nwod

asym etr

0.5

valenc

compared

prot n

in

and

3.

distr bu ions x(Auw),

the

A negativ

asym etr .

using fusion

and

from

asym etr .

si proces

gluon

par met i-

g7’p(x). t o Q2

evig

the

distr butions

x(Au

to of

to

contribu on rof

proces

data evold

be n

are

parton

quarks,

0.1

from tcef

to

the (12)

236

D si t h e and

wher

asym etry

virtual fraction

sel ct d

phot n rof

yb

VMD

the

of proces,

pres nt

depolariz t n evnts

aris ng

from

the

an lysi ,

the

first

term

asym etri

factor proces

and vanishe.

iA i . nderU

and

are,

fi

the

roF QCDC

rof

respctivly,

as umption

the

smal

and

region

PGF

the

a zero

of of

are

the

nevig

:

APGF

know of

The menta ion HERM S. to

subproce

In

the

for

PYTHIA

at AG/G. QCDC rof p k revo the difernt si A G / G 5.

asym etri

real of

from various

inclusve

region

proces

cros

pT

saw

The

Monte

smal ),

> 1.5 two

section

si

as umptions

an lysi ).

and

saw

dominated

yb

Carlo

despite

rof

f O.lG(sta .)

Figure.4)

fact

AG/G

thre and of

fit ed

the

pres nt d. Carlo

semi-ncluv

z.

years

scat ering In

to

spin

the asym etry

gen rato , hadron deut ri m

distribution.

Cernkov

sen it v y

of

obtain

[20].

HERM S

counter,

charged

3He of in

target,

In

198,

leading

that

gluon the

particle

data

pk+.

with

fusion, wohs

an

measurd

predict ons best averg

stcef

a tend cy

tif

model,

from value

the

asym etry

fo

XG

the for

0.17

to AG/G

cros

used

background more

section extrac

negativ

[19].

from

avergd

Carlo this

in

[17]. frag-

found

to

(now Monte

from

saw

normaliz t n

the

l ew

data

model

saw

1=

averg

contribu ons

gen rato JETS

the

GPGF

the relativy

the

), t h e data (as

are

(for

are The

scat ering

thoug

this

this

0.5 Carlo

while

GeV/c

,l ew

nI

os

The The

]81[

> 0.8

pk2 relativy

at

the

HERM S l iw

the

and

hadron quasi-re l the

Identifcao may

whic

distr butions

of polariz t ns

pres nt

no

Ail

sea

tA

under stima ed.

t o large s i compared in Figure.5

a value to

be

phot n

on

interp ted

measur nt .

and

Aq(x) Monte

They x

Ail with

model

OUTLO K

helicty

When

semi-ncluv

QCD.

GQCDC

distr bu ions DIS measur nt. PYTHIA t o .feR dep-inlastc

the

f 0. 4(sy t.)

data

framewok

acording

using

LO in

and

quark

GeV/c

distr butions

to

the

AND first

to

> 1.5

dewohs the

, a s op sed

from

CON LUSIONS

The de p-in last c inclusve functio taneously ment of si lsoa Monte tracted. Furthe inc de t thres old tion extrac ion on t h e helicty

found

tuned

calube

partic pants), polarized

chosen

( lkp various

directly polarized

det rmined

er w

of

are masle

The

semi-ncluv

er w

inter s

shape

0.41 =

6s

and

er w

GeV/c

plots

(13)

par met rs fo

the

phot ns

this

par met rs

the

describ the hig

> AG/G

GPGF

z<

The (exactly, kinemat cs

of

yb

asym etry spin phase

data

taking H

asym etri ,

Quark-Parton

rof phot r duc ion QCD polariz t n

a LO gluon

in

si provide

bet er Thres old

signfcatly

evah

targets.

gained si

of

Cernkov

taking

yield

The Model

up,

whic

sen it v y

imple nt d yb

improve

identfcao a wen counter

and of

in

from

sea

asym etri

hadrons data

sta i cs

polarized

be n

pres nt d

quarks. hig

the

to the

measur nt

have

thes

down,

model

pions

hig polarized

PT

nucleo of As saw

precison

set

in replacd

the with

yb

A

hadron

in

are

the AG/G

the quark on

hig

the

yield measur-

HERM S the with

a

pairs

PYTHIA difernt

as

simul-

si

exCO-

polariz sta i cs

d-quark

a Ring

231

"0.5

d

0.6

0.75

0.4 0.2

4 .........

4

52.1

5.1

57.1

pk

2

(GeV/c)

1

....... .......................................

.... ~

1

0

2.0-

-0.6

-0.4

6.08.0-

Figure plot GeV/c tion most sta istical Imagin

revo rect polariz t on

-1 0.5

si l A

4.

fo prh+ point

nearly sen it v y

, 0.75

The as

and

the er o

Cer nkov

in

1

measur d a functio for

al with

is s h o w n .

mo enta to

I

52.1

counter much

I

5.1

I

57.1

p r

(RICH).

ac ept d

strange

quark

hig er

yb

polariz t on precison

This

GSA

-

>O/GA<(

1 AG/ =+l:

)4.0

2

V/c)

(Ge

Figure sib l t e

the top p ~ ~ for - + & > 1.5 plot is Ail a s a func1.5 GeV/c. The rightis ident cal. Only the

>

plot

’

asym etry:

fo

bot om pk-

each

I

-

- -

black

new

the

5. curves

,1 respctivly. dashe

in

is exp cted

wil the

All

compared AG/G.

are

curves

det ctor

spectrome r.

for

nucleo ,

are

sA

kaon

for Dashed,

ident fy

after

AG/G

for

K,

7r,

to

dif er nt

fits

4.

5. 6. 7. 8. 9.

10. .1 12.

13.

M . Fontan az, D. A. B r a v r , D. von A. Afan sev. C.E K . Ackerstaf e t al, et D.De Schep r K . Abe e t al, Phys. K. Abe e t al, Phys. B. Adeva e t al, Phys. e t al. B. Anderson H.L Lai e t l.a P h y s . M . Gluck e t al. Z . D.de Florian e t al. .M Glick e t al, Phys. Schif.

Har ach, Carlson,

al,

and Nucl.

Phys. Phys.

Instrum.

Nucl.

Rev. Rev.

D58 Let .

Rev.

Rept.

Rev. Phys.

and and

C67(19 5) Rev.

Instrum. Let .

D162 Rev.

D53

B. C. (19 8)

Pire,

A.

97 97(1 83)

Z.

Kotzin a , Wahlquist, Methods

Methods

(19 7) D58 (197)

D57 (19 6)

Phys.

1203

62 (198)

43

1280 (198)

C 8(19 ) Phys. Phys. A 417(98) A 419( 8)

57 4

120

3 5803

Let . Rev.

349

and fo

run.

032

B421 D58 16

(198)

(19 8)

-l,O, and

fo

REF NC S .1 2. 3.

rewol =

dot ed,

OL

asym etri s

a det rmination the new

with

Up er

70 45

349

provide

solid

dot-

Ref.[14]

p particles sea

pos-

quark

and

di-

32

8

T.

K.

Gehrman and Ackerstaf

17.

T.

Sjostrand,

A.

Airapetian

20.

14. 15. 16.

18. 19.

J . El is Structure. tained G.A. L.

and

Schuler Frankfurt

using

Erice,

W.J

e t al.

M.

Karline .

PYTHIA and

Comp. et

Stirl ng,

Phys.

Invited

Aug st

e t al,

al

Phys.

T.

Phys.

Sjostrand, Phys.

Let .

Phys. B46

19 5,

Com .

version Rev.

Let .

Lectur s

5.724

hep- /960128 .

28 Nucl. Let . B230

Rev.

(19 )

at

123

(19 4)

and (in

Phys. (198 )

JETSET pres ),

D53

the

(196)

610

International

Schol

74. B407 14

hep-x/9072

(19 3)

The version

Monte 539

7.410

fo

Carlo

result

Nucleon wer

Spin -bo

Hadron

K.

02

and Maruym

Nuclear and

Elsevir

First Gerasimov-Drel -H arn W.

Physic

Scien

H.

double

B.V

Electromagni (Editors)

Al

Probes

sthgir

for fur

the

GDH-

and

on

rule

the

Experim ntalphysik,

Ruhr-Univers ta Univers ta Univers ta

&

Univers ty Miyaz k

fo

Univers ta

B-90

Moscw,

Pavi .

Physic ,

Univers ta

F-91

Ti b nge , phot n ac el r to

data evig

to

up and dilut on

of

Univers ty

80

Italy

Glasgow, D-970 Swedn

test

the

induce facilty

dev lop

ref ig ator

in

provide

Mainz,

Germany

D-4801

Bochum,

Germany

Erlange ,

0 172-

MA I.

t o the

Germany

new

first

frozen-spi

on

the

A 47r polarized

includes

Pavia,

Ced x,

Tubingen,

the

U.K

Japan

Pavi ,

the

Germany

Germany

Japan

D-6702 for

Bochum,

Nagoy ,

fo

reactions

VeM

Germany

D-4801

Got ingen,

Japan Gif-sur Yvet

prot ns

obtained contribu ons

Chikusa- ,

Nagoy ,

D-91058 Belgium

Gent,

D-509 Miyaz k ,

a newly

the

Bon ,

fo

Got ingen,

Rus ia

Universty,

Chikusa- ,

Lund, Lund,

Mainz,

Univers ty,

Bochum,

D-591 Univers ty

Univers ta

0 172-

Theor.

Bon , Erlange -Nurnbe g,

Stralingsfy ca.

Astron my,

Nagoy

to

Bochum,

Ruhr-Univers ta en

way

A2-Col ab r ti ns

The helic ty dep n ce fo in t h e en rgy range from 20 be n perfo med a t t h e nizM polarized tag ed phot n beam used. The horiz ntal 3He/4He t o maintain the polariz t on incom g phot n beam. The f o pion phot production and rule and the forwa d spin polariz b ty

time.

Germany prot n

France has

The

det ctor

supercondu ting for

longitud nal

be n

exp riments

sy tem,

solid

a thin mode

information Gerasimov-Drel -H a n

Italy

measur d

have

a cir ula y have

target multipo e

be n an lyse

(GDH)

coil

to

the

sum

70.

INTRODUCTION

1.

study experimental deriv

measurem nts

sum

bInst. fur Experim ntalphysik, Physikal c e Institut, Physikal c e Institut, Lab0 orv Subatomaire De p a r t m e n t f o Physic . 1 Physikal c e Institut, De p a r t m e n t f o Physic , Insti ut f u r Kernphysik, Faculty of Engi e r ng. INR, Academy f o Scien . De p a r t m e n t f o Physic , CIRSE, Nagoy Univers ty. INF ezionS di Pavia, De p t . f o Nuclear and CEA Sacl y, DS M / D A P N I A / S P h N , Physikal c e Institut,

new

932

resvd.

polarization

"rey M

"Inst.

htiw Okuno

In

rec nt pos ib l t e

years, fo

the in

the

spin verif cat on

to sixt es

the dep ndent

improve nts

investiga e by

Gerasimov

fo

the

reactions

the

polariz t on Gerasimov-Drel -H a n

i n polarized on [l]

and

the

nucleo: indep ntly

degrs

beam

and

fo

target

fre dom

ther (GDH)

techniques

by

is Drel

sum

fo a special

the and

rule.

nucleo . Hearn

have inter s This

open d

[a],

sum

In in relat s

rule,

the the

042

static the on

wher and the

ance. only inf te exc l nt kind direct using scat ering under stimate the en rgy with decis v the total

longitud nal y

phot n

In

unitarity,

fo multipo e

threshold

fo

the

test

for cros

special

3.0

up

GeV the section

fo

perfo mance

spin

focus

a i74

[7].

on particle

fo

to

of

made structure. some (mainly

MeV

this

the

the

polarized of

fo

the

unpolarized) for

double

rule wil

the

this

MA I

be

for

be n

Compton

the

single

phot production (-204pb)

target. result

at

set

Its

on

pion

the

054 MeV

on

phot production

(Bon )

a t Mainz techni al

the

helic ty wil

prot n.

the

provides

be

published

wer

.16-3[

Al

en rgy

up

dep n ce

to

be

dev lopment combination

The

to

Without

wil

in

invar-

indep ndent

integral the

312 v si

and

gau e

as ociated

GDH

to

obtained:

amplitude.

spin

predict on previously.

ELSA

up

latest

measur ment

and

for

covering

be

m,

phot ns

sta es

also

this

mas

helic ty

(Lorentz scat ering dif cult es

verifd

the

polarized

total configuration) can

becom s

(Mainz)

below

spin oy-

char cter, techni al

and K

cir ula y

GDH-integral.

conti ued

first

mo ent

sections

the

not

pion

polariz t on

The

as:

amplitude

evalu tions

exp rimental solid

chan els

forwa d

to

predict on

at

for

princ les

Due has

rule

double

r7N

physic

sections

phot n- ucleon 1 si caled polariz b lity

eq. spin

the si t h a t fundamental

and

report

+-

basic

theoretical

sum started

det ction. "yp

side

its sum

magnetic

cros

cros

to

to

model

the

be n

80

In

antipar l el

on

ap lied

GDH

EXP RIMENTAL The

or

Due

a crude have

I t is w r i t e n

forwa d

based

the

anom l us

nucleo s.

cal ed

as umption

and

substantial y

left-hand

is

results,

an lyse

the

phot absorption

os

rule

causality)

phot absorption

the

(par l e

The the

en rgies, f o nucleo

data, measurem nts

pion

demand

experimental

experiments,

are

sum

nucleo ,

total

polarized

,yaw

GDH phot n

the

al 2

en rgy.

a sim lar

questionable

The

and

resp ctively

12

The

fo the

fo

0312

2. 2.1.

properties

dif er nc

this any

made

data,

explained

from

a phot n

with

fo

so n

at

pion

models

range

an

was the

[8].

SETUP Circula y

experiment ac el rato longitud nal y

polarized

was

MA I in ung fo er d el ctrons with a was monitored throughout polarimet r. The polariz t on mize sy tematic efcts. [lo]. The phot n f o ref. se t h e m o e n t a f o the sy tem si able to tag MeV [l ]. The tag in by a e + pair det ctor,

Mainz. polarized degr

phot ns

phot ns

car ied

the

el ctrons eficny

out

Circula y

en rgy

The

of phot n in

that

direct on

the

el ctrons. polariz t on exp riment was the

was

at

det rmined

that was

range instal ed

Glasgow-Minz

polarized A

with was

polariz t on radiated conti uo sly

of

phot ns

strained

about

downstream

a precis on

flip ed the

from

by 50

GaAs

was to

randomly the brems trahlung monit red

wer

% 75 evalu ted

tag in MeV

80

fo

the

tag ed

phot n

produced

phot cathode [9]. The fo f 3 % ev ry ac ording spectromet r with throughout main

by by

phot n.

el ctron few

a resoluti n

hadron

means

facil ty routinely

seconds

polariz t on to

whic

This the

det ctor.

fo

brems trahl-

the deliv-

fo

the

experiment

fo

det ction

a Mdler t o min formula an ly-

about 2

The

24

pair this .12 1 2.2.

det c or technique,

in

A

Longitud nal y

The

sonable prot ns. prot ns -

polarized

saw

whic

levoN

wol

luminos t e . per

regula y

the

phot n

inte s y The frozen

flux

polarized

tag ed ern2,

solid a target

targe spin

length from sta e

A butanol techniqu

materi l

whic

calibrated could

prot ns

phot n of

be

(C4H90 )

se u -

butanol

demands

frozen a to al result

evag the

% tneic f

a 10

det rmin

beam

2 mc a luminos ty

target

using

princle

Two

of

load.

yb

refigato

whic

are roF

saw

sur o nde a omgenityh y b a ugeh ac ept n . particles the nucleo of a b o u t 06- 5 one .ke w is integrated 03 pm coper s ol f o scat er d design (length influec that of t h e 1 . 2 K yb a dleif f o 0.48 target are frozen spin si times in t h e

wol a

consitg

placed two

magnet the

polariz t n

Km

serv

that

oT

reach polariz b e

Using

2 %

rea-

polarized

the

the

a separ to precoling

also

pur ose

increas

<

shield. sur o nds techniqu a magnetic

outer

the

ref ig ator.

dleif

about nucleo coling

30

the

of

the

el ctron

around

as roF

the

ref ig ator

si provide

stil ,

woleb an

ac ept n

si presvd

spin of

the

dleif

and

and and

the

the yb the the the

inter al the the

fo mK

dimenso

det c or

revo

spin

and

to

the

(DNP) asembly

targe target with fo

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magnetic

roF

temp ratu es

heat

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par m gnetic radic ls yb chemial techniqu s. in a magnetic dleif of 2.5 Tesla and then spin resona c frequncy t o drive the hyperfin t o be ligneda par l e or antiprle to the 3He/4He dilut on target materi l a horiz ntal of whic er w det rmined yb t h e in er the warm bore f o the polarizng magnet. evapor t , and sevral counter cur ent heat liquefact on f o the 3He/4He gas mixture. final heat exchang r and the mixng chamber mK. The cryogeni comp ne ts of t h e refigato beamlin tubing, whic si t h e c e n t r a l part isolat n vacu m t o reduc the thermal heat si also enclosd yb a n isolatn vacum and proces a magnetic dleif of 2.5 Tesla with are si r e q u i d . This can only be provide complety, resulting i n a reduction of angulr t o a to al y open geom try for t h e scat er d inter al holding lioc si used. In t h i s techniqu the polariz t on proces a t a temperature Tesla with a relax tion time of more than a superconducting, inter al holding lioc that of four layers of NbTi wire wound on a thicknes of 70 pm, such that a signfcat the thres old. As a result of its compat lioc has a kaew outer fringe field, so t h a t the target area si very smal in comparisn to The lioc si coled to a temperature woleb of t h e stil . At t h i s temperature a maxi u homgenity f o the magnetic dleif revo the a n onlie polariz t on measur nt during sy tema ic er o of t h e polariz t n measur nt relax tion polariz t n close t o 09 % a n d

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consi t g

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targe

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previously

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[12,7] given

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243

and t h e evaluated prot n kinet c from a no p r o d u c t i o n proces both helic ty states and orf cor esponds t o quasi fre reactions in t h e dif er nc spectrum.

RESULT

3.

AND

Da t a have be n MeV, t o maxi ze phot production whic open a t 450 wher t h e two single [8]. b e published det rmination fo and the forwa d over stimate the

on

their

under

hydrogen. dif er nc .

on

Misng

the

as umption

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0 nuclei

C and

en rgy

region

distributions

outside has

and

10. .1

S.B. S.D. I. K a r l i n e r , R.L V. Burkert, A.M J . Ahrens G. Anton J . Ahrens K . Aulenbacher H. Olsen I. A n t h o n y

12. 13. 14. 15. 16. 17. 18. 19.

MacCormick C. Bradtke G . Audit S. Altier M. Sauer R . Crawfo d R.A Arndt 0. Hanstein

8. 9.

S.J M.

Gerasimov, Drel ,

A.C

Workman,

taken the

at

phot n MeV

wil

pion

The

contribution

Sandorfi

et

extraction

two yp

chan els

polariz b lity.

be

+

polariz t on

dif er nt

el ctron

pro an lysed

and fo

result

rep s nt in

yp

the the by

The

en rgy

over separ tely.

to al

about

+rm +

the

multipo e

en rgy

the

entire

as

total

cros 10

to

as now

Hal

et et

et et

et

Li,

R.A

Rev. Phys.

Phys.2 (196) Phys. Rev. Let . 16 D 7 (1973) 271 Arndt, Phys. Rev. D 45 Rev. D 4 7 (19 3) 64 Phys. Rev. D 50 (194) MA I Prop sal A2/ -95 ELSA Prop sal 192 published Nucl. Instr. Meth, A Phys. Rev. 14 Instr. Meth. A301 (9 1) Instr. Meth. A368 (19 6) Phys. Rev. C5 (19 6) Instr. Meth. A 643 Instr. Meth A 801 (19 ) Report TC-98/30 (19 8) Instr. Meth. A 378 (19 6) Phys. A 603 (19 6) Rev. C 5 3 (19 6) 430 Phys. A 632 (19 )

SAID

%.

430

(196 )

908 (19 2)

1789

R6 81

391

and (19 7)

(195 ) 41

(19 )

87 230,

698

30 561

498

034 473 143

(soluti n

the

difernc

investiga ed

an lyse

02 -

set ings en rgy

l ew Up phot absorption

section

range

J . Nucl.

al., Maim Bon t o be et al., L.C Maximon, e t a l . , Nucl. a l . , Nucl. et al., e t a l . , Nucl. a l . , Nucl. a l . , INF a l . , Nuvl. e t a l . , Nucl. et al., Phys. et al.,Nucl.

al. et al., et al., and

Sov. Hearn,

Phys.

Z.

the

a yield

REFERENCES .1 2. 3. 4. 5. 6. 7.

that

prot n

the

are

peak

consi ten

orig nated shown Emis

at

for with

zero

SM9 K)

range.

80

fo

The

double data

cros to

]81[

the

below

MeV pion section,

alows and

and

single

GDH

chan els,

054 the

HDT

52

pion MeV, integral

direct

wil 1191

=

OUTL OK

reactions

the spin experimental

en rgy

0

ThisPageIntolyLfBk

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VI .

NEW

FACIL T ES

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K.

Hadron

and Maruym

02

Nuclear and

Elsevir

Scien

Few-body F.

W.

Hersman"

the

Hal

Studies

lA

Laboratory Col ab r ti ns

Universty

few-body scat ering,

outline

with

of

nuclei faciltes

at

have

CLAS.

the

and

what

ben

we

weN

Durham,

recntly

Jefrson the

can

Hampshire,

Labor t y.

measur nt

exp ct

completd from

I discu using

the

HN ro

are

won

polarized

recntly

42830 underway

the

result

complet d

3He

with

using

on

the

measur nt

the

deut ron spec-

STAU

The

Some

Conti u s

linear

4 VeG

separ te hals

Electron

ac el r to s

with

emit ance may

si i n d e p n t

cap bil t es delivr

eith r

hig

evif

40%

of

the

the

oslA

at

than delivr

orde s

have of

treatment.

each

Hal

ac el r to .

meson-xchag A

on cap ble density

exp rim nt

elastic and

alows proven

transfer

10

pA

a stringe t o be particul y and theory exist ng efcts

under stima es

Col ab r tion separ te

er w changes

Acelrato paths

lop9

fo

number

orignal parity-qu l

of magnitude design

to

the

Jefrson meting

thre

of

beams

%57 or

at

reci ulat on. met r,

at

specifaton. polarized

great

used

scat ering

Beam

of

det c ed

elastic

07 woleb

raste ing

wat s,

coinde.

2.5%

It

difernc

won

achievbl

tes and

can two

the from

saw

dewol a

elastic

the

High inelastc

A luminosty

cur ents

cryogeni

exploit of

to

ben

two

pA

Beams

to

5.

fo

routinely

of

02

Acelrato

has

GeV used

provide .

examing

4.0

to

the

G. the x

rof

theori s.

120

precison

the

breakdown.

Relativ s c

dep n i g

targe up

sta ions. enrgy

si w o n

Labor t y

Spectrome rs yb

del

scat ering, to

of

data.

agre m nt,

Resolutin

deut ron,

pA

inte s y.

specifaton.

up

rof

A structure

when

char te

scat ering

improve

devlop The

revaling

Beam

design

end in

04

consit

ac el r t

basic

L AH

Jefrson nuclear

al

beam

than

at of

Labor t y

can

delivr.

IN

from

in

exp rim ntal being

SCAT ERING

mo entum

measur ments

betw n

deut rons

be

excd physic.

evif

ELASTIC

The

The

bet er

can have

for

Beam

with

beams

DE U T E R O N

the

247

resvd.

Jef rson

AC EL R TO

2.

seborP

sthgir

Physic ,

I then nuclei

Electromagni

CLAS

elastic

light

main

perim nt backgrounds lioc lo ps, of induce

fo

exp rimental

prot n

1.

form- act s ment ap roximat on incluso their

and of

lates and tromet rs. on

ciden

B.V

(Editors)

at A

"Departmen

saw exp rim nts:

with Okuno

physic

and

to Thre separ te avilbty

sci yhP

H.

ext n

sy tem

pA

the

cm-2s1

luminos ty elihw

with

oT

el ctrons

thre keping

coinof

agreimpulse

and

method

(HRS)

Petratos.[l] hig

deut ron The

cor e ti ns on

scat er d

The

si t h e

rof

sup re

an and

cap bil ty higest

of ex-er

coling beam-

248

i

1

’-ol

Figure

.1

The

deut ron

I elastic

structure

functio

A(Q2)

compared

with

cal u tions.

942

evr. compared

Da t a

on

with

Figure

to A ( Q 2 ) with the uncertain y Recnt script on dif er in t h e presc i t on GeV/c2. Orden, includ g Tjon withou The deut ron det rmines of existng in t h e hal .

the

1 hows as uming exist ng

si

theor tical are

prot n

exist ng

the

form

The

one

the

deut ron s

Separ tion edg

mentum thre the col ab r ti n. beam cal u tions. tema ic l y Orden, al

e t al.

scat ering

data

023

coulmbs.

Result

form

higer

plot ed

During

than

the

the

no -relativ s c

descript on neari g

are

POLDER, four

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the

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monple observal,

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Within

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seulaV

B(Q2)

with

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hig

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measur nt

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to

estima e

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are

aw its

Q2

of

part

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convert d

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si from

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behavior]

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> 3.5

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POLARIZATION deut ron

in

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er w

range

the

and

(hig )

confirm

from

using

meson

yleso c

to

Figure

scat ering the hig

months

of

rewop

er w

publicat on.[4]

the

The

exp rim nt

undertak

data

2 are compared of verlap,o data romf cal u tion of t h e d a t a

range

earli

from

tzo.

quadr pole worlds

perfomd

cryotarget, taking with

than

the

exist ng

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no -relativ s c

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deut ron

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MIT-Bates.

data

factor t2o

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a J?rench/US wis Armen a

197

data, The

relativ s c

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in

magnetic

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C.[3]

chan el,

recivd data

taken

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-om The and

integra d

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with

theor tical

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cal u tion

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of

Wir nga,

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POLARIMETRY

The

of Rosenbluth magnetic asym etry the el ctri

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polarized ables. el ctrons polariz t on esntialy

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the

TENSOR

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data in

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compa,red for

the

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prot n

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prot n is

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250 Deuteron

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10.

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The precis on

2. t20

data

elastic measurem nts

The translated

tensor scat ering

polariz t on

is compared t o a measur ment f o observa l

fo

the with

A(Q2)

fo

deuteron previous

the

and

mon p le

measur d data

B(Q2).

and

charge

rec nt

in

the form

cal u tions

recoil

polariz t on factor

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(up er).

the

1

25

0.5

0

Figure Sachs form

factor.

el ctri

3.

Double-poariztn

(above)

1

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3

normalized

2

result

4

magnetic

on

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7 6

5

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8

factors

9

scat ering dive

10

plot ed

yb

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the

25

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the

with

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form

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compared

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hig

quality measur nt

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terp et

ap roximat on,

beam A-isobar

measur nt sum 3He Thin

pA

factor GDH

provides

in

al exp riments

able 19. The

be

extrac ed

the

spin

windos

sum

thes

rof

with them of

asym etri

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thre

strength,

to Later, regions

helium

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from

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rule,

exp rim nts

various

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wohs

body measurd

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and

prosed

exchang,

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measuring

rubid m

inclusve

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to

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fields.

the

the SLAC higer

exploit d

into routinely

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polarizng el ctron

inclusve plan i g

D and in coinde

compared dio e

the

the

to knocut

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laser .

with

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data

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region,

for

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the

S

from

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the

polariz t n

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next

prot n

the

si il um nated The whic

to 198

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To of

can

to

to period

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35%

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(CEBAF

multihadron Since

time

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[161

Large

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nuclear

15 -ol[

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end study

a ratio confirm

straw

a

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or

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furthe

be

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complet

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yb

yb

a more under

sta ions.

while

physicertv.

rof

factors.[7]

TA

end

3 as data

two

TARGE can

can

the

and

measur nt

asym etri

operat s

of

and completd are

in form

target

er w

targets

49 1

yb

nucles

yb sy tem.

The

survey luminosty.

The

of

trajectory

chambers figure

this

Lab physic

3He

inclusve

neutron

of of

straw

3He Jefrson

neutron

beam.

a measur nt f o the

data

consit

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dat .[6]

PROG AM

globa

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is a lec-owt vaporized

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rea

plot ed

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HRS

POLARIZED

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of

the

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Extensio

at

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hadron

precsion

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PHYSIC

Few-body

Six

asym etri

glas

spectrome rs. raste d

and

spin

Integrated rule.

target throug

the

can

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rof

the

beam

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A

the

FEW-BODY

isot pe

yb

upward.

polarized

neutron. Consequ tly interp ted as f o the evaw functio quasifre knoc ut. Hearn-G simov The polarized on t h e D1 resonac becoms polarized as a target. ac ept n fo above with 12 Two exp riments, magnetic ormf pare with the early 19. While si underway. 6.

exist ng

in

det rmin

cm,

WITH factor

god

factor

the

tend

to

60

to form

with

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published.

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261

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Punjabi. M. E95-01 vers E94-023 3He( , p) 01 -49E nectio E89-015 Bagh ei. E89-017 Sealock). E89-027 Boeglin. E89-031 tromet r, 230-98E Nucles

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no body wonders a direct exp rim ntal no s a w directly ni no -+ ( e + e - ) from the nucleo

that proved

+

(e+e-).

long

test

K-meson

fo ago

the

yb

y+p+A+K’, whose

matrix

wher

f[k f(e phot n,

+

x e]p

p)k

,k

elmnt

+

+

and f and

in

. p)k

g(e k[g

are

g dep n

mo enta

MC

sy tem

0-

rof rof

x e]p

p

the

(NR

yb

ap roxim t n)

kaon kaon

+O

on

s i given

k

fo =

/kj

phot n

and

(k

and

p).

kaon

The

and diferntal

e si t h e cros

polariz t n section

of

vector (1)

rof

fo

264

linear y

polarized do

-

phot n

c o .e12ifI

dR

Clear parity, (2). tiv s c betw n

difernc The

situation

cor e ti ns

y +*He

betwn

though

two

sizable are

proces

+:He

unpolarized

k21gI2

rof

state

as

cor e ti ns when

compared

+

O+)

si

kaon

(3b)

clear

target

kaon

Of

and

relativ s c

smal er

(ground

0for

(3a) becoms

prot n

k21gI2

- 2Ip +

lfI2k1e evn

+

x 21]k

[p

cx

on

si usefl

to the

to

the

helium

are

establi h

to

nucleo

target

be

ad e

exp rim ntal y

target).

si used

to

[2] If

the

(wher

one

K-A

matrix can

the

dist ngu h

elmnt

relativ rela-

KO

(4)

and

y +4He for

(4)

-+:He* of ers the

do -

dR

(excit d bet er

linear y

polarized

/ e . [k

co

case

to

test

relativ

,OK

(5) parity.

inc de t

The

phot n

diferntal

s i given

cros

yb

section

fo

(4)

0-,

o+,

rof

pl’(~)*

el

K-A

the

rof

+

1 MeV)

1+,

(mon e rg tic)

x P ] ~ ~ ( F ) ~

co wher

sta e

[3] ( ~ ) 2

0.64~-(k-0.96~) /(19 g

k and

are p

threshold,

MeV/c)’

say

mo enta

k

-

1 GeV,

y and of

may

K be

pref abl

CM in

sy tem

to

fo

tes

(6a)

(4).

The

and

(6b).

region,

slight y

above

REF NCES

the

.1 2. 3.

R.H Y. The

Yam guchi,

Milburn, evaw

Phys. functio s

Soryushi n-Ke kyu

Rev. rof

10

Let rs 4He

and

:He

(in

(1963) evah

Jap nes ) ben

75. kindly

25

(1962)

sup lied

47. by

Prof.

Y. Akaish.

Hadron

K.

02

dna Maruym

Nuclear and

Elsevir

Nuclear

Physic

H. Scien

with Okuno B.V

physics

(Editors)

Electromagni

lA

Probes

sthgir

resvd.

265

experiments

STB

1.2-GeV

with

LXS-Toh ku

at

ring

J . Iias gi Laboratory

of

The struct,ion conti uo s is a b o u t the pres nt

nuclear 30 -nIeV constructed Howevr.

fo

stretcher-bo ster

el ctron

to

experimental

Laboratory scien

not

l)o st,er

storage 30 -MeV The In stored tag ed 1

the

ready

The

Ins

for

fo

Scienc ,

Toh ku

Nuclear

Scien

beam

deliv r

Univers ty, at

ring

with

en rgi s

a tag ed prog ams

phot n

(STB

for

Mikamine, Toh ku

up

to

bea,m

nuclear

Univers ty

ring). 250

MeV

for

en rgi s

has

STB

The

with

physic

Sendai

external

with

the

982-0 6, rec ntly

ring up

STB

Japan

si

to

target

1.

complet d

won GeV.

ring.

con-

producing stations, We

a

and

describe

INTRODUCTION

.1

niclea,r

Labora,tory

Nuclear

a future

The

STB

extracted

t he

The strdclier in the phot n

in

1.0 to

el ctron an

ac ept,ed,

pliot, n

and, res arch

In

Li ac

comis n g

stretcher

198

project. ring

beam

and

the

ring.

!leG mode beam

linear

orig nal

(STB

ring.

bo st

in

(30

Xuclear

as pro sal

has

the

storage

production.

stretcher p s) si

operat,ion mode is b e i n g

The

saw

the constructed. also

but

two

functions;

mode

can of

the

in

had

experimental

li ac with more

en rgi s

is than

used

area

half

for

to

operat,ion,

the

target

be n

in

is

dev loped. use

the

up area

LNS to

06

production fo

to

target in

various

are the

exp riment,al

beam are

tA

expected

GeV

ac epts wol

has

decades.

pulse-beam

down;

for

the

SR

to

ring, ring a pulsed

19 7,

80

experiments

work

whic

bo st,

the

radiation

duty experiments. hig -en rgy ac el ration

conri uo s

and

.s 07

physic

was

only plan ed

is

the

1.2

to

and

beam

to

had

stretcher-

not

% fo

nuclear up

on

a 20 -MeV

1.2-GeV

It has stretcher in late

nuclear

and

including

inspection

contributed

pro sed

complex

(about en rgy

ac el rated

experiments

Novemb r, the pres nt

EN RGY

MeV

si

st,retcher

ring for

for

si shown

scale

a, 1 . 8 for

thre ring

ring

sta ions

After

last

150-MeV stretcher

the

started 198.

LOW fo

el ctrons

internal saw

May)

STB

pulse-beam a conti uo s

the

ac el rator

forced

The

University

A

a GeV

el ctron

injector

for

ring

WITH

an

Toh ku in

1967.

for saw

operation,

produces

used

STB

project

at

beams

since

ring GeV

as

be

the

operation dev loped.

of

mode

and

deliv r

They

suc e d

was

t,hen,

ring)

(LNS)

Scien el ctron

with ac el rat,or a prototype

EXPERIMENTS

2. 30 -I e\; el ctrons oc upies

ring physic

fo res arch

for

and

from

factor).

GelT

the

to

safety

a 1.2-GeV

be

the

beam

tag ed

BEAMS in fo

Fig. av ilab e.

various

1.

The

ro m

radio s topes

As

low

en rgy shown

is

no.

2.

in Two

at

pulsed Fig.

the target

heam station 1, t h e

STB stations

from 1,

wher

the ring are

a

26

prepared target

5 ,E

a large

other in t h e

Figure Suclear

stretched

absorption plion

1.

The (1) (2) (:3) (A) (5) (6) (7) (8) Her .

around

experiment. 5 250 dipole station esperi nental

fol wing Study Study .!dutS

Stud>. Col ective lfechanism Search Study

the

ring

for stretcher

In

MeV) for

the is e x t r a d e d

magnetic

wol

1.2-Ck17

beams.

experi ierds no.

1.4s

quasifre

Experiments

can

is

1.

RIA;\I

the

"B(e, ’n) i otion

fo elastic (e,e’p)

and

fo subthreshold for escihtion fo phot -absorption I discus the pos ib lity proces ; Experiment D G R has be n found

in

the

IVQR

(1)

reaction.

heavy

ap roved

be

proces reactions

in

of

nuclei two-phon

firstly

mechanism to (7)

the

"Si(e, ’n) via production

pion excite in

prop sed

used

the

low-en rgy

on

the

heavy

pion

to

the

tag ed

"C(e,e’p)

in double

in

the two-phon by

experiments

already

and

D L M

In "C(7.n) Teras w [l]. charge

(e,ro) 40Ca(-j,n)

reactions.

reactions. and giant exchange

at

out.

reaction.

"C(7,np)

resona ce Evidence

wher located

(150 The

Laboratory

fo

with

wol

reaction. reaction

internal beam

station: el ctrons. station

phot n

car ied

reaction.

nuclei. reaction.

the

the scat ered

continuo s

stations

physic

be n

(e, ’fis ion)

the

photon

en rgy

experimental

nuclear have

GR

tag ed low

is t r a n s p o r t e d t o an lyze

and

(3) in

and

1.2-GeV the

and

ring

a list

with

operation,

ring

Stretcher-Bo ster

is fo fo fo fo

experiments; mode the

from

spectrogmph

en rgy ro i

Science.

1.2-CkI’

for

en rgy

in

a

at

the

LAhIPF

phot -

two-

762

(Lo5 the pliot

Alamoi) piesent, o-absorption.

[2]. no

-

Two GDR

and

in

heavy have

at empts

ion

reactions reported

be n

Two GDR

no hp

d

DGDR

DGDR

z+,/

l;SEL/

GDR

I

through regarde Fig. (1~rot~oi -1ieutron) step thus, reactions. many siInult’aneously,

In

In a. t w o - p h o n

’.

phot n role

Two-phon

GR (b)

pion pe,ts-ovT

2(a), the

as

two-phon

X in

with phot -absorption

two-step first

excita ,ion

suc e iv the

strong phot ns.

phot -absorption pos ihle

GR

-

phon GDR

Two

the

state. excita ion

and

step

zTo(xf,

reaction excita ion

cor espondi g

GDR Coul mb Then

a two-pno n Thus. meson

ion

exchange

mechanism proces ,

reaction

in

cur ent

esp cial y

particle-hole can

of

to

intemediate

the

nucle s

state

for

(a)

phot n

example,

two-phon

states

can

absorb, one

excita ion

is

MEC

phot n

states reaction.

as

To-2

must such

states en rgi s

i s know

nucleus.

the

target

for

shown "can

the

1-oT

the and

reaction

T-)

(T+,

fo

the

fo (proton-neuteron) in

excited projectile

The

double

charge

reaction.

the

7r-)zt T0 2 GDR

be

pion

absorption

the

the

is excited, only question two-phon

the

(MEC).

reactions: (c)

For

the

Phot-absrpin

)c(

various

and

f o another (GDRgGDR) field betw en the target GR proces , howev r; t,he inter sting

To-1

T O

reaction,

excites

2+

T O

~o)ztlTo-l(iTo,

via

GQRorGDR

reaction,

excita ions.

to

states

phon

O+

exchange

particle-hole

up

Howev r, two-phon

’

excited ion

charge

the

virtual t’he

the

,+o

Heavy

states

heavy

double

the the

(b)

reaction )

reaction.

t’he

is

x-

( Z+,

2.

?

I

/

Figure exchange

-

GA?;IL[4].

and

observ

GDR

o+,

(a)

SI [3]

at to

in

example,

hig er

be

As

AT=l

is

to

be

play

shown

heavy

two

3(b). part

in coupling

a

than

an

be

second

In

nuclei

excita ion

excited can

particle-hole The

excitation,

nucleus.

Fig. take an

may

can

provides phot ns excit ng

important the

and,

oc ur?

of GDR

in

ion

a

862

escit,ation. phot n el ctric

is

I-.

AT=l

dipole

In

coupled

3( c)

Fig. absorption

state:

I EC’

with a -1 dipole

1-

nucleon studied plan ing targets cliange

For

tu-o plion the

and

coupled that

of

mechanism

GR

escitation Sl to

with i n nuclear

with in

resona ce extend niucl

bet er

nuclei. the

in

GR

with fo

in

measurem nts

el ctrons, As

nuclear statistics, or

nietl u

the

the to

GR

tlie

absorption

single

the

one-plion

"Ca(

,3.

1.2-GeV

tag ed

reaction sta ,e.

phon s while by

phot -absorption

particle-hole

phon excited

nucleus.

by

at

order

in

by

fo the

main

the Yam zaki

se

and

ES whether

(7.p71)

facil ty

inter st in

course

the

IVGDRSIVGQR

this

states

escite

the

"Ca.

cor esponds isovector

MEC

the

be

t>wo-phon neutrons

-1

and

regarde

may

reactions the

and

target

station.

of

the resona ce

symposium[6],

is

t’he former

behavior

expect

on

various

IXS. property

ew

fo eV\ nuclear

be

giant’

acts

can

One

As

should

the

neutron-particle

ineasuring

this

not.

beam

other

to

SCI OR phot n

to

incident

GR whic

BEAM

,*( . T I ) to

of

phon since

fo

nest

sect,ion escitation

1-

The

the

The excita ,ions.

two-phon

CIR ULATING

TAGX Figure

the

fo

7 .n)

one

in

cros

D G R

GEV pres nted medium

the 2+ is n o t

two type

escitecl

shown. the

phon .

and

mode of

shematical y

double

proces :

a 2+

iso caler

1.2 GeV

the

main

one

neutron-hole

state

the

(I\’GDR);

An

photo

is

with

Thus.

WITH esperinients

con ects

be coupled

resona ce

(Ii-QGR).

EXPERIMENTS

escitation whic

should

phon

tlie isovector giant quatlrupole resona ce a T-J+ (or T+J-) operator. state si t h e proton-particle prot n-hole tjp. The a s the phon escitation . I Suz li [5] predicted t o be a s large a s 8k(i.L’ t o o1m .e the t,wo-plion escape from the two-phon

3.

the

have

does

the are

as

t>o

269

In F i g . The photon placed scintil at,ors thin carbon is removed The el ctrons x 0 2 m ). long light i agi et. There. be n working SCIS ORS detector for charged they can The ient fo photon for lon- en rgy

3,

at

tag ing

the

placed foil

from

The

two

Each fihr.

system, 1.2-GeV

be

t,he experiment

large (Sendai part,icle placed quality

we

show

the

experimental

tem

is

now

area

being

for

inst,al ed.

1.2-GeV

The

f the bending magnet (BM4) i n a snial ro m in the bencli g can b e moved lcna set, at the beam the beam posit on when t,he el ctron emit ing phot ns are detected with one scir til ator si c o n e c t e d with a special Then, phot,omult,ipliers can b e placed target posit on fo t h e ta,g ed photon detector sy t,ems wil b e placed: one very wel in the ES f a c i l t y at INS for CsI Scintil ation System On Radiat,ion consi ting f o 20 pure CsI crystals. The detection, while the lat er for ^/-ray at the target, posit on fo t h e tag ed tag ed phot,on tem is now being examined fo t h e 1.2-GeV el ctron beam circulating is e x p e c t e d to start i n Yay, 20 , nuclear physics but also for G e V en rgy entran

the

fo

maganet. posit on

system

tag ed

consi ts

BTS

The

very

beam fo

photon ring

quickly:

experiments. radiator

and

fo

10 the ac el rated.

a radiator

made rac1it)o

plastic

is i n j e c t e d and t,he plastic scintil ators (5 light guide which couples to a,t a d i s t a n c e from the bending is & o u t 7.5 m from the radiator. is t h e TAGX sytem, which these 15 y e a r s . The other is c a l e d Search): a large scintil ation former system wil b e used maily det ction. As shown i n Fig. photon beam. together with t h e improvethe STB ring. The tag ed and, then, SNL wil serve not nuclear physics.

a

fo

x 3-m 5

has

3,

only

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ThisPageIntolyLfBk This Page Intentionally Left Blank

Hadron

K.

’

02

dna Maruym

dna

reiv slE

Laser

Physic

H. Scien

htiw

onukO B.V

el ctron

T.

Hot a * Fujiwar a,f Kish mot , Miyabe’, Ookuma", Shim zu",

M. T.

M. H. H. C.W.

tering out

At the

Cent r Japan

High at en rgy *Cor esp ndi g

various

the

lA

Probes

sthgir

resvd.

Atomic Synchrotron

Sugay f,

S.C

H.

fo

fo

Energy

Physic ,

phot production

M.

Wangd

ew

C.

Radiation

Univers ty

Nation l

built

cir ulating

fo in

Universty,

and Wak y m phot n

el ctron

+

phot n synchrotron author.

beams

el ctrons

radiation E-mail:

(laser synchrot n pj.ca.u-ak so.pncr@at oh

60-852,

beam. thres old,

near

Toy nak ,

Inage, beamline A

facil t es

radiation

15-742,

in

phot n)

laser-induc

Nagoy

the facilty,

world

D. Seki’,

560-43,

sy tem,

Osak

Japan

Insti ute,

90-856,

N7S

5E2,

Univers ty,

Tokai,

Japan

Can da

Japan

Nagoy

Japan

Japan 350

Wak i",

Japan

Korea

263-85,

is utilzed [1,2]. enabl s

A.

Mibe",

Japan

Yam gat

Osak

with det ctor is nearly

Ooba’,

679-5143,

Japan

TA

by

el ctron

og yH ASU

641-02,

Sas ki’,

KimJ,

T.

Ibar ki,

45701,

Seoul

Chiba

T.

T.

Z.Y

Japan

Res arch

Engi e r ,

Matsuok ",

679-5143,

Taiw n

Sask to n,

Da,"Bt

Mihoga k , 658-01,

46-802,

S.

Toykaw",

"ios Y

Energy

OH

FACIL TY produce

M.

og yH Mikazu,

Yam gat ,

Sask tchew n,

H.

,’iaw K

N.

10-

Nagoy

Kyot

H.

Ohas i",

and

Atomic

Scien

a 2.4 GeV 8 eVG fo meson

Sakguchi",

1529,

Insti ute,

Universty,

Wak y ma,

Y.

og yH

Athens,

Universty,

Changd,

A.

To yam h,

Yorita",

W.C

Kobe, Mikazu,

Taipe

PHOTON

en rgy

third-gen ration

Univers ty,

Universty,

ELECTRON

Matsum rak>c,

T.

Univers ty,

Osak Chiba

Insti ute,

Ishikaw’,

Universty,

Japan

Universty,

Yam gat

Res arch Coleg,

Sin ca,

Res arch

Center,

Kyot Seoul

T.

Osak Universty,

Ohio Nagoy

Nomachi",

T.

T.

Kona

Res arch

Academi

Asano’,

Iwat h, M.

Physic ,

Physic ,

Res arch

Y.

Rang charyul ’@,

Surniham ~’, Yonehar b,

K.

SPring-8

T.

S . Makinop,

Nakno",

Nuclear

3 1 - 9 1 19 5 , J a p a n f o Physic , f o Physic , f o Physic , f o Physic , f o Physic , f o Physic , of Physic , for I n t e g r a t e d Japan f o Physic , Medical cir ulating

Imai’,

T.

Ooshimaf,

Scien

the

72

at Akimuneb,

K.

Kumag i",

for

LASER 1.

Electromagni

facil ty Hicksg,

N.

Miyach ,

M.

Y.

Wangd,

Ahn",

K.

Y.

SPring-8, fo

(Editors)

phot n , J.K.

"Res arch 567-04, bDepartment ’Jap n dInsti ute "Jap n fAdvanced Ibar aki gDepartment hDepartment ’Department JDepartment kDepartment ’Department "Departmen "Cent r 46-803, ’Department *Wak y m

fo

Nuclear

nm

laser

optim zed

complet d.

phot n

backs t-

to

car y

SPRING-8 backw rd SPring-8,

for

nuclear us

to

Compton produce

the

scat ering physic

world’s

the

hig est hig est

studies

1

27

latnemir pxE

Figure

.1

The

Laser

en rgy laser el ctron facil ty a t BL3 EP, ,I is c i r c u l a t i n g with the straight section. produces GeV phot ns The maximu en rgy wavel ngth. The LEPS 350 nm Ar laser. At q5p threshold. y p -+ the maximu phot n beam is i t s flat inte si y sufer from hig inte si y beams. Another feature is LEP is also polarized a t lower phot n en rgy. phot ns i n wide en rgy can be monitored on fo the beamline. When the el ctron beam direction. At 1.5 GeV) are within about 1 cm at t h e target The en rgy fo the sy tem. The bending f o recoil el ctron. The the downstream end layers f o 50 pm thick scintil ator ar y. Phot ns

Electron

Phot n

phot n one

fo =

The

Compton

whic facil ty

pres nt, When en rgy

hig

the

scat er d LEP

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magnet sil con

beamlines be

LEP produces

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shorter becom s

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maxi um Howevr,

point

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The scat ering

constructed (Fig.

laser used is

det rmined

for

is hig er

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the

the

the only

det rmined fo strip 1.5

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angle

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the

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3.5

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ring

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in

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beam

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214

PHYSIC 3. At iment

the

meson

change

as

old

universal

be gluon

the

be

(VMs)

vector

[3].

exchang

to

glueba

study terms

of

meson In

the helicty

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are the

of

as

proces

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done

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si

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proces

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proces

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proces due

can measurnt

theory,

ben

prosed

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hig

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yb be

OZI

to

studie

si s c a t e r d

[4].

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Pomern

polarized proces,

The

y fluct a es

that MV

includg

phot n

and

of

unpolarized

One

phot r duction

into

MV

hci w

introduce

5q phot r duction.

yb and/or S

polarized knocut

section

.]5[

of

the

si l e w yb Pomer n t o describ exchang

Pomern

5 q phot r duction, the cros exchang

only

difractvely

saw

syad woN

the

discue.

It

cros

section

target,

from

know

the

from

means

fo

that l iw

thres -

ew

a nucleo,

exp rvector

can meson

clarify

-xe the

the

As can

an in

DETECORS

4.

Si

Figure

surem nt vert x time-oflgh

The

4.

The

LEPS det c ors

fo

LEPS

the

det c or (TOF)

De0tce

pirtS

tengaM

Dielop

-J

q5

det c or

(SVTX),

setup

phot r duction wal.

multi-wre

si

shown in

in drift

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Fig. chambers

forwad

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direct on.

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It

si consit

design

a dipole

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for silcon

the

meaand

strip a

275

along

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the

planes

dipole

magnet

beam and

(z

si 0 3 pm and enrgy s ol for located upstream The sen it v for t h e DC2 a n d DC2) ro ’u (for The TOF l aw of l aw consi t long. The tim ng The TOF start ring. sA a s t a n d a r d a flight length 2 GeV/c mo entum ben tes d separ tely integrated test roF other exp riments, det c ors f o 14 superconducting target .

at

has

openig

the

(S Ds).

SVTX (DC1) DC3) the

of

are DC1 5 planes;

In

has

from

at

lev.

an 3 m

this

the

up

from

thicknes

02

achievd. signal

12 x

the

K/T

separ tion

dipole

target.

of

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lead

of comp ne ts

pole

of 2 SD and u ) si

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the

The

cm the TOF x

2 m

storage

magnet of

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wide 8 GeV

scint l a g

of of

consit

mc

y from

25

posit n

(z,

cm idew y , ’y a n d the

thick

RF

labor t y

the

z, , ’ z

det c or of

in

fut re

ben

length

SVTX

5 planes

and from

case, Each

"0 1

downstream

4 mc

Brems t ahlung

-

we

the

The

The measur

with

particles psec

and

cent r.

and

up

has

ring.

of

The

laser

inte s y sy tem phot production

a

has

l iw

el ctron

produce be n

be

increasd

phot n

at

beam

a ylwen

up

construc ed si plan ed

devlop

to and

rof

with

the

1 x l o 7 /sec the test early .0 2

maxi u

beamlin , are

after

BL3 EP

the underway.

enrgy

of

beam

at

comisng.

The

2.4

VeG

Spring-8.

first

test

has The

exp rim nt

The

ben

beam

det c or

suc-

$ of

REF NCES .1

A.

2. 3.

C. T. (1978)

4.

5. 6.

7.

An

fiber Also,

polarized

to

SUM ARY

5. cesfuly

has 135 cm ediw and 5 cm hig si 0 6 c m . The dleif strength si 1 T y ) of ingle-sd silcon strip det c ors the strip pitch si 021 pm. With the particle ident f ca io . A MWDC and a pair of MWDC (DC2 and x 0 3 cm hig rof area si 08 mc wide DC3. Each f o the DC2 and DC3 the DC3). si used t o measur times of flight 0 4 plastic scint l a or bars of dimenso: resoluti n of b e t e r than o = 01 signal with 0 = 1 2 psec si made setup, the TOF l aw si located 4 m. of a charged particle si a b o u t si exp ct d a t bet er than 4o LEP beam and yb using the of t h e det c or has be n just started. a phot n calorimet , made radi t on lengths, covers from 03 solenid magnet si being built rof

M. Nucl.

A. .M A.

Scientf,

T.

Schaerf, H. Donachie Derick Nak no I. T i t o v ,

Sandorfi, Sci.

,03 Nucl.

Bauer,

J.

380

LeVin,

Phys. D. Spital,

R. and

e t al. 197

H.

and

Y.

C. (1983)

Oh

[ZEUS

P.

sweN V. Toki,

and

E.

G.

Thorn,

No.

Landshof,

2 192)( D. R . einY

Col ab r ti n],

S. N .

Phys. Excit ng Yang,

Physic Phys.

Giordan

1 8-7

and Phys.

Let .

Rev.

with

G.

and

M.

F.

,692B Let . Let .

Pipk n,

weN

Matone,

Rev.

IE

72

B37 ,

(192) Acelrato

79,

4361

952

Mod.

(197)

(196) Faciltes,

Phys.

Trans. 261

50,

World

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REMARKS f o the S E S U M ac el r to describ . The yek isue luminosty. I t si found that the luminosty nuclei f o hicw the lifetm s i 1 min. oT of t h e ac el r to aspect si t h e coling-stak lat ice structure of t h e DSR, ynchrous Optim zation on thes problems fects. RI-Xray colisn, the most importan of t h e el ctron beam under the low-emit anc design si ned rof t h e comp ne ts of t h e sy tem has t o b e instal ed in t h e DSR. phase 1 of t h e RIBF project si under the si exp ct d t o start the constru i from

pa er, at the

Yano

Kat yam Got Kawguchi

N . Inabe N . Inabe I. T a n i h a t , Y . Batygin M . Waksugi

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REF RENCES 2.

least

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592

List Abramowicz,

Tel Halin

Akaish,

vi A

Asakw,

Universty

Cheon,

gnoT-1

Yonsei

Chiba,

Junsei

KE Tsuneo

En’yo,

Fries,

Kyot

Hatsud,

[email protected]

Universta fo

Hirenzak,

Kyot

Le , Levy,

f o Toky Seoul Osak

Universty Tel

Earle Kazushige

[email protected]. ci,osak -u.ac.jp takeshi.omubr@jp

Yonsei

suho ng

Avi

Aharon Maed,

pj.ca,u-akaso.ics.syhp@otomisik

KE

Houng

Lomn,

jckim@phya,snu.ac kr

Universty

Takeshi

Su

Universty Universty

Osak

Universty

Maschuet Tohku

@Ins.toh ku.ac jp

pj.ca oyk t-u.s nc@am yat k

Nationl

Hidek Komatsubr,

kas gi

Universty Tad fumi

[email protected]

Universty

Chan

Kishmot,

[email protected]

Universty

Tohku

Jong Kohri,

Universty

Dongshi

Takeshi

@phys.nar-wucj

[email protected]

Metroplian

Taeg

Katym,

zaki

[email protected]

Toky

Jirohta

@ unh.ed

f o Regina

Mashide Kasgi,

hersman

Universty

Universty

Mo n

Hampshire

Universty

Garth

Inuzka,

New

Women’s Osak

ed.negnibeut-inu.kisyhp.tip@

grabm yr

pjca.u-ot yk.syhpcs,ybur@adustah

fo

Tom aki Huber,

Tuebing

Universty

Nar

juergn.fis@phykt-mcd

pj.ca.ukoh t.syhp.adbmal@tomihsah

Universty Satoru

Muench

Universty Tohku

Bil

[email protected]

HiroshmaUnvety

Tetsuo Hersman,

Technolgy

pj.ca u-ot yk.syhpcs.np@oyne

Universty Osamu

and

endo p j . c a . u - a m i h s o r i h . l p e h . n o t o h p @

Pet r Hashimot,

Agriculte

Universty

Technis

Grabmy,

Kim,

fo

HiroshmaUnvety Juergn

Jeong,

pj.ca.ukoh t.syhp.raelcun@abihc

Univ.

Satoru

Hota,

[email protected]

Universty

Ichita Endo,

@tan shi.ke jp

junsei.ch ba@ke .jp

Toky

Hideto

a1zt.ucd

yuki p j . c a . u - a y o g a n . s y h p . h t - c u n @

Universty Tohku

Masmi Emura,

halin @ ak ish

Nagoy Masyuki

Endo,

Universty

KE Yoshinr

Chiba,

Purticmns

of

Universty

Instiue

levy

f o Technolgy

@ phya.onseickr

@alzt.uci

lom n

[email protected]

@mitlns.mit.edu

296

Mart,

fo Universty

Tery Maruym, Masike,

Fuki Akira

Meyr,

fo Universty

Koich

Miyake,

Electro-Cmunia Women

Nakyoshi, Kazuki Nomura,

Tom Okuno,

ik n

KE toru.nma@kejp

Oyam,

fo Trento Universty

Ken

Pshenic ov, Rangchryul,

Chary Sakguchi,

Atsuhi Sak mot ,

fo Academy

Universty

fo

Osak

Sasktchewn

Universty

Toshiak

imekas

Universty Toky

ude.bsynus.scisyhp.cinot

pj.ca.u-aw zan k.s mbiehca @ot mak s

f o Technolgy Instiue

Kyot

ur.kstiort.rni.Ol a@vonhcinehsp

pj.ca.u-ak so.ics. yhp@hcugak s

Kanzw

Seich

Sciens

[email protected]

Universty

Akita Atsuhi

[email protected]

@p ar

Toky Yasuhiro

Sciens

[email protected]

Rusian

Koh

Sakemi,

Shibat,

fo

SUNY

flaR

Shibat,

Academy

f o Bon INR,

Igor

pj.ca oyk t-u.s yhp.lcun3kam yo

Rusian Universty

Ewald

@ scien.ut

nid alro

Toky

fo

INR,

Eduar

Sas ki,

[email protected] ys ti ech.a jp [email protected]

Universty Giusepna

Rap ,

f o Technolgy Instiue

@tanshi.kejp

KE

Orlandi,

Paul,

@tanshi.kejp

KE

Hidek

Paryev,

[email protected] isoyak n

Toky Makot

1 .sciehm-uajp

f o Toky Universty

KE

Kazuo

@ tanshi.kejp

nak@qws

Universty Scien

Kozi

Oka,

[email protected]

[email protected]

Ehime

Naki,

[email protected]

Universty

KEWDESY

Nori

ke.jp

otum

Kunih ro

Nik,

ytisrev nU

KiFK

Nagno,

.mhr-unibocde

pj.ca.u-ak so.ics. yhp.mk@ekayim

Musahino

Masyuki Nak,

[email protected]

osamu.nrit@

Osak

orij Y Muto,

mas ike@mvb. iglobe.n jp

Universty

Toshi

.tanshikejp

Technolgy

KE

Osamu

Murat,

maruy@esnl

Bochum

Osak

Motba,

Toky fo

Uni.

Yoichr Monmatsu,

[email protected]

Universty Ruhr

Wern

Indoesia

@nucl.phystieaj

ikas

Universty

@ed.physakit-ucj

Instiue

shibat @HL.r i kyot -u.ac jp

fo

Technolgy

shibat @nucl.phys ti ech.a jp

297

Suda,

fo Physical Instiue

Toshim Sugimot ,

Toy

Ueda, Ukai,

[email protected]

Utsunomiya,

Hiroak

Women’s

[email protected]

Pharmceutil

ytisrev nU

wad @my-phan . c jp

KE Sakue

Yamguchi, Yamguchi,

Yoshi Yamur,

Hisahko Yamshit,

[email protected]

Ehime Mashiro

Universty

Yamzki,

Hiroht Yamzki,

f o Toky Okaym

y 921

f o Scien Universty

Shizuoka

Cancer Tohku

Centr

yam [email protected] ac.jp yam shita@n rs.go jp

Universty

pj.ca.ukoh t.snl@ikaz may

KE Yuji

Toky Koich Katsuhide

pjca.u-emihe.ics. yhp.lswq@ugam y

Universty

Haruo

Yoshida,

[email protected] -wu.ac jp

Universty Meij

Yamd,

Universty

Kona

Yoshicka

.dpcehim-uaj

ukai@t nashi.ke jp

Nar Yukio

Yazki,

uedat m@ehi gw

KE

Umeot,

Ins.toh ku.ac jp

[email protected]

Universty

Kumatro

Wad,

tamae4

Universty

Ehime

Tamotsu

pj.ca.u-iuk f.ylp a.mutnauq@

sua ki

KE

Katsuo

suda@rik xp.riken.go jp

sumi@hs. irok u- .ac jp

Universty

Hirokazu Tokush ,

Universty

Universty

Tohku Tadki

Tezuka,

Interaiol Fuk i

Toshi

Tame,

Resarch

shojiro.sugimot @ke .jp

Hiroshma

Yoshi Suz ki,

Chemical

KE

Shojir

Sumi,

dna

HiroshmaUnvety

Woman’s

[email protected]

Christan

Universty

pj.ca.oykot-u.s yhp3tikaz y

pj.ca.u-amihsorih.lpeh.notohp@adihsoy

@tan shi.ke jp

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