From Collective States to Quarks in Nuclei: Proceedings of the Workshop on Nuclear Physics with Real and Virtual Photons Held in Bologna (Italy), November 25–28, 1980

421 Pages·1981·5.625 MB·English

by  R. Vinh Mau (auth.), Hartmuth Arenhövel, Anna Maria Saruis (eds.)

Lecture Notes
in scisyhP
Edited by J. Ehlers, Mtinchen K. Hepp, Zijrich
R. Kippenhahn, Miinchen H. A. Weidenmtiller, Heidelberg
and J. Zittartz, Ktiln
Managing Editor: W. BeiglbGck, Heidelberg
137
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Springer Werlag
Berlin Heidelberg New York 1891
Editors
Hartmuth Arenhijvel
lnstitut rM Kernphysik Johannes Gutenberg-Universitgt
D-6500 Mainz
SMaaArrnuiniaas
Centro Studi e Ricerche
.E“ Clementel”
2 inizzaM aiv .N.E.N.C
I-40138 Bologna
NBSI 3 -540-10570-OS pringer-VerlagB erlinH eidelbergN ewY ork
NBSI O -387-10570-0S pringer-VerlagN ewY orkH eidelbergB erlin
This work is subject to copyright. All rights are reserved, whether the whole or part
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Wart” Munich.
0 by kpringer-Verlag Berlin Heidelberg 1981
Printed in Germany
Printing and binding: Beltz Offsetdruck, HemsbachlBergstr.
215313140-543210
ECAFERP
ehT workshop MORF" EVITCELLOC SETATS OT SKRAUQ NI "IELCUN no nuclear physics using
real dna virtual photons sah been organized yb C.N.E.N., Centro Studi e Ricerche
.E" Clementel" in Bologna (Italy) no rebmevoN 25-28, 1980, in the framework of the
nuclear physics activities of the Institute.
ehT central idea of this workshop saw to review recent developments in the field
of probing nuclei with electromagnetic interaction for both experiment dna theory,
to discuss open problems dna to try to look into the future of novel theoretical
concepts dna experimental techniques. ehT main topics were: i) the NN interaction
dna the ydob-ynam problem, ii) collective ,anemonehp iii) baryons dna snosem in
nuclei, iv) quarks in nuclei, dna v) present dna future experimental facilities.
All invited talks are contained in these proceedings dna are organized following
the program. In addition, 43 contributed papers have been published in a separate
emulov dna distributed to the participants. About one-third of them sah been pre-
sented orally.
ehT workshop sah been sponsored yb the Research Department TIR of the Italian
Nuclear Energy Committee (C.N.E.N.). ehT generous collaboration of the yalcaS-NEC
Nuclear Physics Department, the Institute of Nuclear Physics of the Mainz University,
the Max-Planck-lnstitute for Chemistry, Mainz, the Frascati National Laboratories,
the emoR NFNI Sanit6 dna Physics Institute, dna the Physics Institutes of the
avoneGLa~il~angoloB Universities is gratefully acknowledged. Particular thanks are eud
to Mrs. .M Accorsi, .rD .G Bacchetta, Dr. .S Stipcich, friends, younger scientists
dna students for having kept the workshop running efficiently dna cheerfully.
Mainz-Bologna, January ,41 1891 .H Arenh~vel A.M. Saruis
VI
Detail from a relief by lacopo della Quercia (15th century).
This photograph was taken from "S. Giacomo Maggiore ni Bologna".
by Frederico Cruciani.
Organizing Committee:
.H Arenh~vel, Mainz University
P.J. Carlos, NEC Saclay
.C Ciofi degli Atti, INFN SanitY, amoR
.C Coceva, NENC Bologna
.E eD Sanctis, INFN, Frascati
.M Giannini, avoneG University
M. Rho, CEN Sac3ay
A.M. Saruis, CNEN Bologna
.B Schoch, Mainz University
Coordinator: ANNA AIRAM ,SIURAS angoloB.NENC
Secretariat: .M IVONNA
Editorial Board: .G ABELLI, .R ABELLI, .P INNEC
Sponsored by
Comitato Nazionale Energia Nucleare, Research Department TIR
ELBAT FO STNETNOC
I. EHT NN NOITCARETNI DNA EHT YDOB-YNAM MELBORP
The Paris Nucleon Nucleon Potential, weN Developments .......................... 1
R. VINH UAM
Recent Developments in the Bonn Potential ........... ............................ 10
K. EDNILOH
Variational Approach to Many-Body Problems in Finite Nuclei ................. 20
S. ITASOR
II. COLLECTIVE ANEMONEHP
Magnetic Resonances and the Spin Dependence of the Particle-Hole Force ....... 13
S. DLAWERK
A Mean Field Approach to the Description of Nuclear Structure:
Interpretations and Predictions ..... ................................................. 42
B. SOCITAMMARG
Many-Body Aspects in Electron Scattering at Intermediate Energy ............. 55
B. FROIS
The Giant Dipole Resonance and the °-1' °-2 Photonuclear Sum-Rules ........... 65
.O SAGIHOB
Electromagnetic muS Rules ........................................................ 72
G. INIDNALRO
Status of Nuclear Critical Opalescence ........................................... 82
J. EMROLED
Inelastic Electron and Proton Scattering to Pion-Like Nuclear Excited
States .......................................................................... 39
H. TOKI and .W ESIEW
The Nuclear a-Excitation ......................................................... 102
K. KCEBNEGNILK
III. SNOYRAB DNA SNOSEM IN IELCUN
Three-Body Wave Functions and Electromagnetic Interactions ................... 511
C. CIOFI DEGLI ATTI, E. ECAP and .G EMLAS
Electrodesintegration of Few-Body Systems .................................... 125
I. SICK
Exchange Currents in the Deuteron ........................................... 136
H. LEV~HNERA
Pion Production off Light Nuclei ............................................ 148
J.M. TEGAL
Scaling Laws in High Energy Electron-Nuclear Processes ........................ 158
.M BOTMEHC
Total Photonuclear Absorption Cross Section Measurements Below the Pion
Photoproduction Threshold ..... . .............................................. 168
P.J. SOLRAC
Quasi-Deuteron Effects at Intermediate Energies ............................ 178
B. HCOHCS
Direct Mechanism in Knockout Reactions with Real and Virtual Photons ....... 186
S, BOFFI
Vl
IV. SKRAUQ IN IELCUN
A Model for Hadrons Based no the TIM gaB Model ............................... 691
JoJ. ED TRAWS
ehT Chiral gaB Model dna the Little gaB . ..................................... 502
.V OTNEV
ehT Color Degree of Freedom dna Multiquark States ............................ 212
.H NESAAGUH
Topological Interpretation of Multiquark States ............................... 322
B. UCSELOCIN
Search for Dibaryonic Resonances of Small Mass BDQ( < 2.3 GeV) .............. 432
.G SAMAT
Experimental Search for Dibaryon Resonances ................................... 342
.E ZTIHCSOB
V. TNESERP DNA ERUTUF STNEMIREPXE DNA SEITILICAF
Present Status of (ee'p) Experiments ........................................ 152
.S EZEIHC-KCRUT
Future (e,e'p) Experiments at OKI ............................................. 852
.C ED VRIES, T. ED TSEROF Jr., C.W. ED ,REGAJ .E JANS, J.H. ,HCOK
L. LAPIKAS, .R ,SAAM .H ED VRIES dna P.K.A. ED TTIW STREBUH
Saclay Activities in Electro- dna Photonuclear Physics at Intermediate
Energies and Future Prospects ................................................... 772
.C LHUHCS
Coincidence Measurements with High Energy Electrons ............................ 682
J.S. LLENNOC'O
Polarization Experiments .................................................... 692
K.H. FFOHTLA
Experiments with Monochromatic dna Polarized Photon-Beams .................... 213
L. FEDERICl, .G ,ONADROIG .G ,ENOTAM .P ,AZZOCIP .R CALOI, L. ,ONASAC
M.P. ED ,ELACSAP .M MATTIOLI, .E POLDI, .C ,FREAHCS .P ,REFLEP
.D .,IREPSORP .S INALLURF dna .B IMALORIG
Photon Scattering ............................................................ 523
.B Ziegler
Neutron Spectrometry dna v-Ray Transitions .................................... 933
.C AVECOC
Photonuclear Physics with Synchrotron Radiation ............................... 843
.M.W OCIREBLA dna .A IRANILOM
VI. EHT ERUTUF FO RAELCUN SCISYHP HTIW EHT CITENGAMORTCELE EBORP
muideM Energy Physics with C,W. Electron Accelerators ....................... 358
.D LESHCERD
Future Developments in Pion- dna Kaon-Nuclear Physics dna the ME Probe:
Examining Electromagnetic Entrails ................................... .......... 863
J.M. GREBNESIE
Quarks in Nuclei ................. . ............................................ 375
.W.C GNOW
emoS Issues in Photonuclear Physics .......................................... 385
.C ARAZT
Novel Techniques in Photonuclear Physics ..................................... 393
.C FREAHCS
Vll
Intermediate Perspectives ................................................. 403
T.E.O. NOSCIRE
List of Participants ...................................................... 410
Author Index ............................................................... 414
THE PARIS NUCLEON NUCLEON POTENTIAL
NEW DEVELOPMENTS
R. VINH MAU
Division de Physique Th~orique x, I.P.N. - Orsay 91406
and LPTPE, Universit~ P. et M. Curie - Paris 75230
Introduction
It is now believed that. hadrons are made of subhadronic constituents
like quarks, gluons, etc... One is then entitled to demand that a theory of nuclear
forces should be derived from the degrees of freedom of those fundamental consti-
tuents. During the last two years, several attemps I have been made in this direc-
tion. The available results, however, are still uncertain.
As a matter of fact, in a nucleus the following situation is somehow
expected :
)i for short internucleon separation distances where the overlap of the nucleons
is important, the interaction between the nucleons is certainly dependent on
the subhadronic degrees of freedom.
)ii for large internucleon separation distances, because of confinement, only
color-singlet objects, i.e. hadrons themselves, can be exchanged between the
nucleons. The interaction ,si then, dependent on the hadronic degrees of free-
dom. It ,si in this case, unnecessary and uneconomical to take into account
explicitly the quark and gluon degrees of freedom.
In view of these considerations, I think that a fruitful and reasonable
approach to the problem of nuclear forces is to proceed from the outer fringe towards
the inner core, namely one should
)i try to determine carefully and accurately the long (LR) and medium range (MR)
forces from the hadronic degrees of freedom,
)ii try to determine the short range (SR) forces from a reliable model bringing
the subhadronic (quarks, gluons, etc...) degrees of freedom into play.
The dividing line between the two regions may not be sharply defined
and in principle there could be an intermediate region where the interplay of both
types of degrees of freedom is significant. Moreover, this dividing line depends on
the size of the domain where the quarks and gluons are confined in a hadron (big
bag versus little bag).
x Laboratoire associ~ au C.N.R.S.
V(r)
subhadronic hadronic
degrees of degrees of 0.5 fm <~ rc~< 1 fm
freedan freedcrn
\
r
fig. I
The Paris NN potential is constructed along these lines of thought, na-
mely
)i the LR + MR part are due to particle or multiparticle exchanges.
ii) as no definite and reliable results, at present, are available from subha-
dronic models we prefer to determine, at least provisionally, the SR part
from experiment, especially as the wealth of data -some of them of high pre-
cision- is now enormous.
The LR + MR part of the interaction
The derivation of the (LR + MR) parts of the Paris NN potential has
been reported several times at various places 2. Due to lack of time and space, I
shall not repeat it here. Let me only recall that they include the one-pion, two-
pion, and ~ and A| mesons (as parts of the three-pion) exchange contributions. The
two-pion exchange contribution was derived via dispersion relations from pion-
nucleon phase shifts and pion-pion S- and P- wave amplitudes. In this way, the pro-
perties of mesons and their interactions both amongst themselves and with nucleons-
i.e. the degrees of freedom of mesons and of isobars- are taken into account automa-
tically and completely.
Before proceeding further in the determination of the SR forces, we
have to check whether our calculation provides a realistic description of the actual
(LR + MR) N-N forces. For this,we have compared
i) the peripheral (J > 2) phase shifts calculated from these contributions with
the experimental ones
ii) the equivalent potential derived from this (~ + 2~ + ~ + A )I exchange inter-
actio n with the phenomenological potentials.
These comparisons 3 show good agreement with phenomenology. However,
they are second order comparisons and we believe that a direct comparison with
data is even more meaningful. Recently, the polarization for low energy (6 - 20 MeV)
pp and np scatterings has been measured with a high degree of accuracy 4. As pola-
rization depends only on the P and higher partial waves and as in turn these partial
waves are mostly sensitive to the (LR + MR) forces, we have compared our predictions
with these data 5. The results are shown in Figures 2 and 3. The agreement between
theory and experiment is very satisfactory.
30 0,6 0
A °
v %~" oo,
-.001
c _-- Mc~E~9 ,, -.002
'oo.- 300--
-.0~ ~OO.-
.00,- ~
fig. 2
The analyzing power in pp scattering.
The solid lines refer to the Paris potential predictions. The dashed line to
the MAW-X phase shift analysis.
.031 ~ . SIRAP --
//.'t"' "l ,~. teTDNRA la .....
40. -o V~ONROT et at.
D RELHCTUH te .L= /
. , V o o :
-03 X LEENANN et aL ,~ . ~ 10. .""
,Q.
20,.~ . ~ 5IRAF
• 02 ..
.01 " I TDNR,~., et al .......
C0. lO. . . . . .51 i • - . . -20. , - ' .T-o~-
oIT )b VeM( 8crn )seerged(
fig. a3 fig. 3b
np polarization at 90 ° c.m.
angle as function of labora-
np polarization at 14.2 and 6.9 MeV
tory kinetic energy. The refs.
as function of c.m. angle.
for experimental points can be
found in Tornow et al. 4.