title:
SU(6) breaking effects in the nucleon elastic electromagnetic form
  factors

abstract:
  The effects of SU(6) breaking on the nucleon elastic form factors are
investigated within the constituent quark model formulated on the light-front.
It is shown that the kinematical SU(6) breaking caused by the Melosh rotations
of the quark spins as well as the dynamical SU(6) breaking due to the
mixed-symmetry component generated in the nucleon wave function by the
spin-dependent terms of the quark-quark interaction, can affect both GEn(Q**2)
and GMp(Q**2)/GMn(Q**2). The calculated GEn(Q**2) is found to be qualitatively
consistent with existing data. while the calculations of GM(Q**2) based on the
plus component of the current are found to be plagued by spurious effects
related to the loss of the rotational covariance in the light-front formalism.
These unwanted effects can be avoided by considering the transverse y-component
of the current. In this way our light-front predictions are found to be
consistent with the data on both GEn(Q**2) and GMp(Q**2)/GMn(Q**2). Finally, it
is shown that a suppression of the ratio GEp(Q**2)/GMp(Q**2) with respect to
the dipole-fit prediction can be expected in the constituent quark model
provided the relativistic effects generated by the Melosh rotations of the
constituent spins are taken into account.


title:
The Role of Ground State Correlations in the Single-Particle Strength of
  Odd Nuclei with Pairing

abstract:
  A method based on the consistent use of the Green function formalism has been
developed to calculate the distribution of the single-particle strength in odd
nuclei with pairing. The method takes into account the quasiparticle-phonon
interaction, ground state correlations and a "refinement" of phenomenological
single-particle energies and pairing gap values from the quasiparticle-phonon
interaction under consideration. The calculations for 121Sn and 119Sn that were
performed in the quasiparticle$\otimes$phonon approximation, have shown a
reasonable agreement with experiment. The ground state correlations play a
noticeable role and mostly improve the agreement with experiment or shift the
results to the right direction.


title:
Are there universal freeze-out parameters for central 158AGeV Pb+Pb
  collisions?

abstract:
  Earlier attempts to extract parameters of kinetic freeze-out in Pb+Pb
collisions at 158$A$GeV are critically reviewed. Many of these analyses have
used approximations which have significant impact on the extracted parameters.
Simple estimates are obtained which attempt to avoid the most critical
approximations. It is pointed out that constraints based on pion interferometry
are less reliable than those from momentum spectra. A universal set of
freeze-out parameters from transverse mass spectra would require T > 135 MeV
and <beta> < 0.35.


title: Electro-weak Reactions for Astrophysics

abstract:
  The status of "ab initio" microscopic calculations of the 2H(p,gamma)3He and
3He(p,e+nu_e)4He reactions is reviewed. The methods used to generate accurate
nuclear ground- and scattering-state wave functions, and to construct realistic
electro-weak transition operators are described. The uncertainties in the
theoretical predictions, particularly those relevant to the p-3He weak capture,
are discussed. For the dp radiative capture, the theoretical results are
compared with the TUNL data in the energy range 0--100 keV.


title: Spin observables for pion production from pd collisions

abstract:
  We have calculated the proton analyzing power A_{y0} of the pion-production
reaction from pd collisions for one energy close to threshold and for another
in the region of the $\Delta$-resonance. A fair reproduction of the
experimental data could be obtained in both cases with a model which includes
isoscalar and isovector $\pi N$ rescatterings in s waves, as well as the p-wave
rescattering mechanisms mediated by the $\pi NN$ and $\pi N \Delta$ vertices.
For the analyzing power at threshold we found that the initial-state
interaction (ISI) is also quite important.


title: Collective states from random interactions

abstract:
  The anharmonic vibrator and rotor regions in nuclei are investigated in the
framework of the interacting boson model using an ensemble of random one- and
two-body interactions. Despite the randomness of the interactions (in sign and
size) we find a predominance of L(P)=0(+) ground states and strong evidence for
the occurrence of both vibrational and rotational band structure.


title: The rho meson in a nuclear medium

abstract:
  In this work, propagation properties of the rho meson in symmetric nuclear
matter are studied. We make use of a coupled channel unitary approach to
meson-meson scattering, calculated from the lowest order Chiral Perturbation
Theory lagrangian including explicit resonance fields. Low energy chiral
constraints are considered by matching our expressions to those of one loop
Ch.P.T. To account for the medium corrections, the rho couples to pion-pion and
kaon-antikaon pairs which are properly renormalized in the nuclear medium.


title:
Dense Nuclear Matter: Landau Fermi-Liquid Theory and Chiral Lagrangian
  with Scaling

abstract:
  The relation between the effective chiral Lagrangian whose parameters scale
according to Brown and Rho scaling("BR scaling") and Landau Fermi-liquid theory
for hadronic matter is discussed in order to make a basis to describe the
fluctuations under the extreme condition relevant to neutron stars. It is
suggested that BR scaling gives the background around which the fluctuations
are weak. A simple model with BR-scaled parameters is constructed and
reproduces the properties of the nuclear ground state at normal nuclear matter
density successfully. It shows that the tree level in the model Lagrangian is
enough to describe the fluctuations around BR-scaled background. The model
Lagrangian is consistent thermodynamically and reproduces relativistic Landau
Fermi-liquid properties. Such points are important for dealing with hadronic
matter under extreme condition. On the other hand it is shown that the vector
current obtained from the chiral Lagrangian is the same as that obtained from
Landau-Migdal approach. We can determine the Landau parameter in terms of
BR-scaled parameter. However these two approaches provide different results,
when applied to the axial charge. The numerical difference is small. It shows
that the axial response is not included properly in the Landau-Migdal approach.


title: Determination of the Delta++ magnetic dipole moment

abstract:
  We study the elastic and radiative pi+ p scattering within a full dynamical
model which incorporates the finite width effects of the Delta++. The
scattering amplitudes are invariant under contact transformations of the spin
3/2 field and gauge-invariance is fulfilled for the radiative case. The pole
parameters of the Delta++ obtained from the elastic cross section are m_Delta =
1211.2 \pm 0.4 MeV and Gamma_Delta = 88.2 \pm 0.4 MeV. From a fit to the most
sensitive observables in radiative pi+ p scattering, we obtain mu_Delta = 6.14
\pm 0.51 e/2m_p for the magnetic dipole moment of the Delta++.


title: Mean field theory for global binding systematics

abstract:
  We review some possible improvements of mean field theory for application to
nuclear binding systematics. Up to now, microscopic theory has been less
successful than models starting from the liquid drop in describing accurately
the global binding systematics. We believe that there are good prospects to
develop a better global theory, using modern forms of energy density
functionals and treating correlation energies systematically by the RPA.


title:
Properties of superdeformed fission isomers in the cranked relativistic
  Hartree-Bogoliubov theory

abstract:
  The rotational and deformation properties of superdeformed fission isomers in
the $A\sim 240$ mass region have been investigated within the framework of the
cranked relativistic Hartree-Bogoliubov theory. The dependence of the results
of the calculations on the parametrization of the RMF Lagrangian has been
studied. The rotational properties are best described by the NL1 force.


title:
Time-odd mean fields in the rotating frame: microscopic nature of
  nuclear magnetism

abstract:
  The microscopic role of nuclear magnetism in rotating frame is investigated
for the first time in the framework of the cranked relativistic mean field
theory. It is shown that nuclear magnetism modifies the expectation values of
single-particle spin, orbital and total angular momenta along the rotational
axis effectively creating additional angular momentum. This effect leads to the
increase of kinematic and dynamic moments of inertia at given rotational
frequency and has an impact on effective alignments.


title: Nature of Chiral Transition in QCD and Sigma Meson

abstract:
  After showing the characteristic features of the chiral transition in QCD at
finite temperature $T$, we note the significance of the sigma-mesonic mode in
the chiral transition : Sigma meson may be regarded as the "Higgs particle" in
QCD, though the existence of such a mode in the real world is still unclear. We
show the properties of the sigma meson in hot and/or hadronic matter, from
which we propose experiments to reveal the existence the sigma meson clearly;
the experiments include relativistic heavy-ion collisions to create hot
hadronic matter, and electro-production in heavy nuclei.


title: The d' dibaryon in the quark-delocalization, color-screening model

abstract:
  We study the questions of the existence and mass of the proposed $d'
(IJ^P=00^-)$ dibaryon in the quark-delocalization, color-screening model
(QDCSM). The transformation between physical and symmetry bases has been
extended to the cases beyond the SU(2) orbital symmetry. Using parameters fixed
by baryon properties and $NN$ scattering, we find a mild attraction in the
$IJ^P=00^-$ channel, but it is not strong enough to form a deeply bound state
as proposed for the $d'$ state. Nor does the (isospin) I=2 N$\Delta$
configuration have a deeply bound state. These results show that if a narrow
dibaryon $d'$ state does exist, it must have a more complicated structure.


title: Neutron beta decay and the current determination of Vud

abstract:
  Measurements of neutron beta decay observables required to determine
$|V_{ud}|$ are reaching the 0.1% accuracy. In this paper we review the
calculation of the decay rate of this process, discuss its relevant
uncertainties, and obtain an expression that is precise at the $10^{-4}$ level.
Our analysis clearly shows the necessity of measurements of $\lambda$, the
ratio of axial/vector couplings. The current situation in neutron beta decay is
that one cannot yet quote a single consistent value for $|V_{ud}|$ from it. We
also discuss the region of parameter space in the $|V_{ud}|$--$\lambda$ plane
where new physics effects should lie, if they contribute to neutron beta decay.


title:
Ginzburg-Landau equations for superconducting quark matter in neutron
  stars

abstract:
  We investigate magnetic properties of color superconducting quark matter
within a Ginzburg-Landau approach. The simultaneous coupling of the quark
fields to gluonic and electromagnetic gauge fields leads to rotated
electromagnetism with a massive (Higgsed) and a massless photon-gluon field. We
derive the Ginzburg-Landau equations for superconducting quark matter taking
into account the rotated electromagnetism in the general case when the rotation
angle is an arbitrary function of the coordinates. We solve these equations for
an isolated vortex in superconducting quark matter. We obtain a solution for
the magnetic and gluomagnetic fields and expressions for the calculation of the
penetration depth and the quantized magnetic flux in quark matter. For this
case we have demonstrated that the occurence of electric and color Meissner
currents is a consequence of the color superconducting state of quark matter.


title: Reply to the comment on 'Validity of certain soft photon amplitudes'

abstract:
  We respond to the accompanying Comment on our paper, 'Validity of certain
soft photon amplitudes'. While we hope the discussion here clarifies the
issues, we have found nothing which leads to a change in the original
conclusions of our paper.


title:
The Off-Shell Nucleon-Nucleon Amplitude: Why it is Unmeasurable in
  Nucleon-Nucleon Bremsstrahlung

abstract:
  Nucleon-nucleon bremsstrahlung has long been considered a way of getting
information about the off-shell nucleon-nucleon amplitude which would allow one
to distinguish among nucleon-nucleon potentials based on their off-shell
properties. There have been many calculations and many experiments devoted to
this aim. We show here, in contrast to this standard view, that such off-shell
amplitudes are not measurable as a matter of principle. This follows formally
from the invariance of the S-matrix under transformations of the fields. This
result is discussed here and illustrated via two simple models, one applying to
spin zero, and one to spin one half, processes. The latter model is very
closely related to phenomenological models which have been used to study
off-shell effects at electromagnetic vertices.


title: Antiproton-deuteron annihilation at low energies

abstract:
  Recent experimental studies of the antiproton-deuteron system at low energies
have shown that the imaginary part of the antiproton-deuteron scattering length
is smaller than the antiproton-proton one. Two- and three-body systems with
strong annihilation are investigated and a mechanism explaining this unexpected
relation between the imaginary parts of the scattering lengths is proposed.


title:
Charge Symmetry Violation in $pn\to d \pi^0$ as a Test of Chiral
  Effective Field Theory

abstract:
  Chiral effective field theory predicts a specific charge symmetry violating
amplitude for pion production. This term is shown to provide the dominant
contribution to the forward-backward asymmetry in the angular distribution for
the reaction $pn\to d\pi^0$, for reasonable values of the mass difference
between down and up quarks, $\delta m_N$. Using a value $\delta m_N\approx$ 3
MeV leads to a prediction of a 10 standard deviation effect for a TRIUMF
experiment.


title: Coulomb and nuclear breakup of three-body halo nuclei

abstract:
  We investigate dissociation reactions of loosely bound and spatially extended
three-body systems. We formulate a practical method for simultaneous treatment
of long-range Coulomb and short-range nuclear interactions. We use $^6$He
(n+n+$\alpha$) and $^{11}$Li (n+n+$^{9}$Li) as examples and study the
two-neutron separation cross sections as functions of target and beam energy.
Individual Coulomb and nuclear as well as interference contributions are also
extracted.


title:
The decay $\rho^{0}\to \pi^{0}\pi^{0}\gamma$ and the role of
  $\sigma$-meson

abstract:
  We study the radiative decay $\rho^{0}\to\pi^{0}\pi^{0}\gamma$ within the
framework of a phenomenological approach in which the contributions of
$\sigma$-meson and $\omega$-meson intermediate states and of the pion-loops are
considered. We conclude that the $\sigma$-meson amplitude provides the dominant
contribution.


title:
Semiempirical Shell Model Masses with Magic Number Z = 126 for
  Superheavy Elements

abstract:
  A semiempirical shell model mass equation applicable to superheavy elements
up to Z = 126 is presented and shown to have a high predictive power. The
equation is applied to the recently discovered superheavy nuclei Z = 118, A =
293 and Z = 114, A = 289 and their decay products.


title:
Nuclear Shell Effects near the r-Process Path at N=82 in the
  Relativistic Hartree-Bogoliubov Theory

abstract:
  Evolution of the shell structure of nuclei near the neutron drip line is
investigated in the Relativistic Hartree-Bogoliubov (RHB) theory. By
introducing the vector self-coupling of $\omega$ meson in the RHB theory, we
reproduce successfully the experimental data on the shell effects about the
waiting-point nucleus $^{80}$Zn. With this basis, it is shown that the shell
effects at N=82 in the inaccessible region of the r-process path remain strong.
In contrast, a quenching exhibited by the HFB+SkP approach is shown to be
incompatible with the available data. Consequently, the neutrino-driven
mechanism of the nucleosynthesis is supported.


title:
Enhanced Event-by-Event Fluctuations in Pion Multiplicity as a Signal of
  Disoriented Chiral Condensates at RHIC

abstract:
  The factorial moments of the pion multiplicity distributions are calculated
with HIJING and UrQMD and found to be independent of the pT range included, in
contrast to recent simulations with the linear sigma model which leads to large
enhancements for pions with transverse kinetic energies below 200 MeV. This
supports the use of the ratio of the factorial moments of low and high pT pions
as a signal of ``new'' physics at low momentum scales, such as the formation of
disoriented chiral condensates.


title:
Faddeev Calculations of Proton-Deuteron Radiative Capture with Exchange
  Currents

abstract:
  pd capture processes at various energies have been analyzed based on
solutions of 3N-Faddeev equations and using modern NN forces. The application
of the Siegert theorem is compared to the explicit use of $\pi$- and
$\rho$-like exchange currents connected to the AV18 NN interaction. Overall
good agreement with cross sections and spin observables has been obtained but
leaving room for improvement in some cases. Feasibility studies for 3NF's
consistently included in the 3N continuum and the 3N bound state have been
performed as well.


title: The Nambu-Jona-Lasinio model of light nuclei

abstract:
  The Nambu-Jona-Lasinio model of the deuteron suggested by Nambu and
Jona-Lasinio (Phys. Rev. 124 (1961) 246) is formulated from the first
principles of QCD. The deuteron appears as a neutron-proton collective
excitation, i.e. a Cooper np-pair, induced by a phenomenological local
four-nucleon interaction in the nuclear phase of QCD. The model describes the
deuteron coupled to itself, nucleons and other particles through one-nucleon
loop exchanges providing a minimal transfer of nucleon flavours from initial to
final nuclear states and accounting for contributions of nucleon-loop anomalies
which are completely determined by one-nucleon loop diagrams. The dominance of
contributions of nucleon-loop anomalies to effective Lagrangians of low-energy
nuclear interactions is justified in the large N_C expansion, where N_C is the
number of quark colours.


title:
On the Delta-Delta component of the deuteron in the Nambu-Jona-Lasinio
  model of light nuclei

abstract:
  The probability P(Delta-Delta) to find the Delta-Delta component inside the
deuteron, where Delta stands for the Delta(1232) resonance, is calculated in
the Nambu-Jona-Lasinio model of light nuclei. We obtain P(Delta-Delta) = 0.3%.
This prediction agrees good with the experimental estimate P(Delta-Delta) <
0.4% at 90% of CL (D. Allasia et al., Phys. Lett. B174 (1986) 450).


title:
Dynamics of low-energy nuclear forces for electromagnetic and weak
  reactions with the deuteron in the Nambu-Jona-Lasinio model of light nuclei

abstract:
  A dynamics of low-energy nuclear forces is investigated for low-energy
electromagnetic and weak nuclear reactions with the deuteron in the
Nambu-Jona-Lasinio model of light nuclei by example of the neutron-proton
radiative capture (M1-capture) n + p -> D + photon, the photomagnetic
disintegration of the deuteron photon + D -> n + p and weak reactions of
astrophysical interest. These are the solar proton burning p + p -> D +
positron + nu_e, the pep-process p + electron + p -> D + nu_e and the neutrino
and anti-neutrino disintegration of the deuteron caused by charged nu_e + D ->
electron + p + p, anti-nu_e + D -> positron + n + n and neutral nu_e(anti-nu_e)
+ D -> nu_e(ant-nu_e) + n + p weak currents.


title:
Strange hadronic stellar matter within the Brueckner-Bethe-Goldstone
  theory

abstract:
  In the framework of the non-relativistic Brueckner-Bethe-Goldstone theory, we
derive a microscopic equation of state for asymmetric and $\beta$-stable matter
containing $\Sigma^-$ and $\Lambda$ hyperons. We mainly study the effects of
three-body forces (TBFs) among nucleons on the hyperon formation and the
equation of state (EoS). We find that, when TBFs are included, the stellar core
is almost equally populated by nucleons and hyperons. The resulting EoS, which
turns out to be extremely soft, has been used in order to calculate the static
structure of neutron stars. We obtain a value of the maximum mass of 1.26 solar
masses (1 solar mass $M_o \simeq 1.99 \cdot 10^{33} g$). Stellar rotations
increase this value by about 12%.


title:
Poincare' Covariant Current Operator and Elastic Electron-Deuteron
  Scattering in the Front-form Hamiltonian Dynamics

abstract:
  The deuteron electromagnetic form factors, $A(Q^2)$ and $B(Q^2)$, and the
tensor polarization $T_{20}(Q^2)$, are unambiguously calculated within the
front-form relativistic Hamiltonian dynamics, by using a novel current, built
up from one-body terms, which fulfills Poincar\'e, parity and time reversal
covariance, together with Hermiticity and the continuity equation. A
simultaneous description of the experimental data for the three deuteron form
factors is achieved up to $Q^2 < 0.4 (GeV/c)^2$. At higher momentum transfer,
different nucleon-nucleon interactions strongly affect $A(Q^2)$, $B(Q^2)$, and
$T_{20}(Q^2)$ and the effects of the interactions can be related to $S$-state
kinetic energy in the deuteron. Different nucleon form factor models have huge
effects on $A(Q^2)$, smaller effects on $B(Q^2)$ and essentially none on
$T_{20}(Q^2)$.


title:
NN-->NNpi from the effective field theory point of view: short comings
  and gains

abstract:
  Based on a counting scheme for the application of chiral perturbation theory
to pion production in NN collisions p-wave production is studied. It is
demonstrated that, contrary to the s-wave production where loops enter at too
low an order to allow the scheme predictive power, there are certain p-wave
observables where parameter free predictions are possible. These predictions
are consistent with experimental data. We show that the investigation of
charged pion production yields a constraint on a contribution to the
three-nucleon force with a spin-isospin structure that could resolve the $A_y$
puzzle in $nd$ scattering.


title:
The Very Low Energy Solar Flux of Electron and Heavy-Flavor Neutrinos
  and Antineutrinos

abstract:
  We calculate the thermal flux of low-energy solar neutrinos and antineutrinos
of all flavors arising from a variety of neutrino pair processes: Compton
production (including plasmon-pole diagrams), neutral current decay of
thermally populated nuclear states, plasmon decay, and electron transitions
from free to atomic bound states. The resulting flux density per flavor is
significant (10E8-10E9/cm2/sec/MeV) below about 5 keV, and the distributions
fill much of the valley between the high-energy edge of the cosmic background
neutrino spectrum and the low energy tails of the pp-chain electron neutrino
and terrestrial electron antineutrino spectra. Thermal neutrinos carry
information on the solar core temperature distribution and on heavy flavor
masses in the range of 1 keV. The detection of these neutrinos is a daunting
but interesting challenge.


title: Transverse momentum dependence of directed particle flow at 160 AGeV

abstract:
  The transverse momentum ($p_t$) dependence of hadron flow at SPS energies is
studied. In particular, the nucleon and pion flow in S+S and Pb+Pb collisions
at 160 AGeV is investigated. For simulations the microscopic quark-gluon string
model (QGSM) is applied. It is found that the directed flow of pions $v_1(y,
\Delta p_t)$ changes sign from a negative slope in the low-$p_t$ region to a
positive slope at $p_t \geq 0.6$ GeV/c as recently also observed
experimentally. The change of the flow behaviour can be explained by early
emission times for high-$p_t$ pions. We further found that a substantial amount
of high-$p_t$ pions are produced in the very first primary NN collisions at the
surface region of the touching nuclei. Thus, at SPS energies high-$p_t$
nucleons seem to be a better probe for the hot and dense early phase of nuclear
collisions than high-$p_t$ pions. Both, in the light and in the heavy system
the pion directed flow $v_1(p_t, \Delta y)$ exhibits large negative values when
the transverse momentum approaches zero, as also seen experimentally in Pb+Pb
collisions. It is found that this effect is caused by nuclear shadowing. The
proton flow, in contrary, shows the typical linear increase with rising $p_t$.


title: Nucleon resonances in omega photoproduction

abstract:
  The role of the nucleon resonances ($N^*$) in $\omega$ photoproduction is
investigated by using the resonance parameters predicted by Capstick and
Roberts [Phys. Rev. D {\bf 46}, 2864 (1992); {\bf 49}, 4570 (1994)]. In
contrast with the previous investigations based on the ${SU}(6) \times {O}(3)$
limit of the constituent quark model, the employed $N^* \to \gamma N$ and $N^*
\to \omega N$ amplitudes include the configuration mixing effects due to the
residual quark-quark interactions. The contributions from the nucleon
resonances are found to be significant relative to the non-resonant amplitudes
in changing the differential cross sections at large scattering angles and
various spin observables. In particular, we suggest that a crucial test of our
predictions can be made by measuring the parity asymmetry and beam-target
double asymmetry at forward scattering angles.


title: Effective range function below threshold

abstract:
  We demonstrate that the kernel of the Lippmann-Schwinger equation, associated
with interactions consisting of a sum of the Coulomb plus a short range nuclear
potential, below threshold becomes degenerate. Taking advantage of this fact,
we present a simple method of calculating the effective range function for
negative energies. This may be useful in practice since the effective range
expansion extrapolated to threshold allows to extract low-energy scattering
parameters: the Coulomb-modified scattering length and the effective range.


title:
Projected shell model study for the yrast-band structure of the
  proton-rich mass-80 nuclei

abstract:
  A systematic study of the yrast-band structure for the proton-rich, even-even
mass-80 nuclei is carried out using projected shell model approach. We describe
the the energy spectra, transition quadrupole moments and gyromagnetic factors.
The observed variations in energy spectra and transition quadrupole moments in
this mass region are discussed in terms of the configuration mixing of the
projected deformed Nilsson states as a function of shell filling.


title: Gluonic Correlations in Matter

abstract:
  We derive the analogue of the QCD low energy theorems for the scalar and
pseudoscalar gluonic correlators in nuclear matter. We find that the scalar
correlations are depleted while the pseudoscalar correlations are enhanced to
leading order in the nuclear matter density. We briefly discuss the
consequences of these findings on the QCD spectrum.


title: The Neutron Halo in Heavy Nuclei Calculated with the Gogny Force

abstract:
  The proton and neutron density distributions, one- and two-neutron separation
energies and radii of nuclei for which neutron halos are experimentally
observed, are calculated using the self-consistent Hartree-Fock-Bogoliubov
method with the effective interaction of Gogny. Halo factors are evaluated
assuming hydrogen-like antiproton wave functions. The factors agree well with
experimental data. They are close to those obtained with Skyrme forces and with
the relativistic mean field approach.


title:
Effect of differences in proton and neutron density distributions on
  fission barriers

abstract:
  The neutron and proton density distributions obtained in constrained
Hartree-Fock-Bogolyubov calculations with the Gogny force along the fission
paths of 232Th, 236U, 238U and 240Pu are analyzed.
  Significant differences in the multipole deformations of neutron and proton
densities are found. The effect on potential energy surfaces and on barrier
heights of an additional constraint imposing similar spatial distributions to
neutrons and protons, as assumed in macroscopic-microscopic models, is studied.


title: Collective Quadrupole Excitations in Transitional Nuclei

abstract:
  The generalized Bohr Hamiltonian was used to describe the low-lying
collective excitations in even-even isotopes of Ru, Pd, Te, Ba and Nd. The
Strutinsky collective potential and cranking inertial functions were obtained
using the Nilsson potential. The effect of coupling with the pairing vibrations
is taken into account approximately when determining the inertial functions.
The calculation does not contain any free parameter.


title:
Six-body calculation of the alpha-deuteron radiative capture cross
  section

abstract:
  We have computed the cross section for the process d + alpha -> 6Li + gamma
at the low energies relevant for primordial nucleosynthesis and comparison with
laboratory data. The final state is a six-body wave function generated by the
variational Monte Carlo method from the Argonne v_18 and Urbana IX potentials,
including improved treatment of large-particle-separation behavior. The initial
state is built up from the alpha-particle and deuteron ground-state solutions
for these potentials, with phenomenological descriptions of scattering and
cluster distortions. The dominant E2 cross section is in reasonable agreement
with the laboratory data. Including center-of-energy and other small
corrections, we obtain an E1 contribution which is larger than the measured
contribution at 2 MeV by a factor of 7. We calculate explicitly the
impulse-approximation M1 contribution, which is expected to be very small, and
obtain a result consistent with zero. We find little reason to suspect that the
cross section is large enough to produce significant 6Li in the big bang.


title: About the parity-non-conserving asymmetry in n+p--->d+gamma

abstract:
  The parity-non-conserving (pnc) asymmetry in \vec{n} + p \to d+\gamma at
thermal energies has recently been calculated using effective field-theory
methods. A comparison of this calculation with much more elaborate calculations
performed in the 70's is made. This allows one to assess the validity of this
new approach as presently used. It is found to overshoot the almost exact
calculations by a factor close to 2 for the contribution involving the ^3S_1
component of both the initial and final states. This is much larger than
anticipated by the authors. This discrepancy is analyzed and found to originate
from the over-simplified description of the deuteron and capture states which
underlies the new approach. The claim that earlier determinations of the sign
would be in error is also examined. It is found that the sign discrepancy is
most probably due, instead, to the fact that the pion-nucleon interaction
referred to by the authors corresponds to a parity-non-conserving potential
with a sign opposite to what is currently used. Some estimates and constraints
relative to the pnc piNN coupling, h^1_{\pi}, which the above asymmetry is
dependent on, are reviewed. Further details are given in an Appendix.


title: G-Matrix Equation in the Resonating-Group Method

abstract:
  The G-matrix equation is most straightforwardly formulated in the
resonating-group method if the quark-exchange kernel is directly used as the
driving term for the infinite sum of all the ladder diagrams. The inherent
energy-dependence involved in the exchange term of the normalization kernel
plays the essential role to define the off-shell T-matrix uniquely when the
complete Pauli-forbidden state exists. We analyze this using a simple solvable
model with no quark-quark interaction, and calculating the most general
T-matrix in the formulation developed by Noyes and Kowalski. This formulation
gives a certain condition for the existence of the solution in the
Lippmann-Schwinger resonating-group method. A new procedure to deal with the
corrections for the reduced masses and the internal-energy terms in the Lambda
N - Sigma N coupled-channel resonating-group equation is proposed.


title:
Deuteron Breakup pd\to pnp in Specific Kinematics and Short-Range
  NN-Interaction

abstract:
  Deuteron breakup processes $p+d\to (NN)_{s,t}+N$ are studied in the
kinematics of backward elastic pd-scattering at law relative momenta of the
NN-pair $k\sim 0-50 MeV/c$ for initial energies $T_0=0.5-2.5 GeV$ in the
framework of the known mechanisms of the $pd\to dp$ process including
rescatterings in the initial and final states. A considerable suppression of
the $\Delta-$ and $N^*-$ isobar excitation mechanisms is found for the
production of the singlet $(NN)_s$-pair. As a result, one nucleon exchange
mechanism can be identified in the cross section and polarization observables
by the node of the half-off-shell NN$(~^1S_0)$-scattering amplitude, $t(q,k)$,
at $q\sim 0.4 $ GeV/c.


title:
gamma* N -> Delta transition form factors: a new analysis of the JLab
  data on p(e,e'p)pi0 at Q^2=2.8 and 4.0 (GeV/c)^2

abstract:
  Recent JLab data of the differential cross section for the reaction
p(e,e'p)pi0 in the invariant mass region of 1.1 < W < 1.4 GeV at four-momentum
transfer squared Q^2= 2.8 and 4.0 (GeV/c)$^2$ are analyzed with two models,
both of which give an excellent description of most of the existing pion
electroproduction data below W < 1.5 GeV. We find that at up to Q^2 =
4.0(GeV/c)^2, the extracted helicity amplitudes A_{3/2} and A_{/2} remain
comparable with each other, implying that hadronic helicity is not conserved at
this range of Q^2. The ratios E_{1+}/M_{1+} obtained show, starting from a
small and negative value at the real photon point, a clear tendency to cross
zero, and to become positive with increasing Q^2. This is a possible indication
of a very slow approach toward the pQCD region.Furthermore, we find that the
helicity amplitude A_{1/2} and S_{1/2}, but not A_{3/2}, starts exhibiting the
scaling behavior at about Q^2 \ge 2.5(GeV/c)^2.


title: Photonuclear Reactions of Three-Nucleon Systems

abstract:
  We discuss the available data for the differential and the total cross
section for the photodisintegration of $^3$He and $^3$H and the corresponding
inverse reactions below $E_\gamma = 100$ MeV by comparing with our calculations
using realistic $NN$ interactions. The theoretical results agree within the
errorbars with the data for the total cross sections. Excellent agreement is
achieved for the angular distribution in case of $^3$He, whereas for $^3$H a
discrepancy between theory and experiment is found.


title: The one-pion-exchange three-nucleon force and the $A_y$ puzzle

abstract:
  We consider a new three-nucleon force generated by the exchange of one pion
in the presence of a 2N correlation. The underlying irreducible diagram has
been recently suggested by the authors as a possible candidate to explain the
puzzle of the vector analyzing powers $A_y$ and $iT_{11}$ for nucleon-deuteron
scattering. Herein, we have calculated the elastic neutron-deuteron
differential cross section, $A_y$, $iT_{11}$, $T_{20}$, $T_{21}$, and $T_{22}$
below break-up threshold by accurately solving the Alt-Grassberger-Sandhas
equations with realistic interactions. We have also studied how $A_y$ evolves
below 30 MeV. The results indicate that this new 3NF diagram provides one
possible additional contribution, with the correct spin-isospin structure, for
the explanation of the origin of this puzzle.


title:
Mott dissociation of D-mesons at the chiral phase transition and
  anomalous J/Psi suppression

abstract:
  We investigate the in-medium modification of the charmonium breakup processes
due to the Mott-effect for D-mesons at the chiral phase transition. A model
calculation for the process J/Psi+pi --> D+D^*+ h.c. is presented which
demonstrates that threshold effects in the thermal averaged breakup cross
section can be explained as a Mott transition where final state quark-antiquark
bound states enter the continuum of resonant states at the QCD phase
transition. Applications to heavy-ion collisions within a modified Glauber
model scenario and the phenomenon of anomalous J/$\psi$ suppression in the CERN
NA50 experiment are addressed.


title: Correlations and the Dirac Structure of the Nucleon Self-Energy

abstract:
  The Dirac structure of the nucleon self-energy in symmetric nuclear matter as
well as neutron matter is derived from a realistic meson exchange model for the
nucleon-nucleon (NN) interaction. It is demonstrated that the effects of
correlations on the effective NN interaction in the nuclear medium can be
parameterized by means of an effective meson exchange. This analysis leads to a
very intuitive interpretation of correlation effects and also provides an
efficient parametrization of an effective interaction to be used in
relativistic structure calculations for finite nuclei.


title: Effective Chiral Theory for Radiative Decays of Mesons

abstract:
  An extended $U(3)_L\bigotimes U(3)_R$ chiral theory which includes
pseudoscalar and vector meson nonets as dynamic degrees of freedom is
presented. We combine a hidden symmetry approach with a general procedure of
including the $\eta'$ meson into chiral theory. The $U(3)_L\bigotimes U(3)_R$
and the SU(3) symmetries are broken by the mechanism based on quark mass
matrix. Meson radiative decay widths are parameterized in terms of a single and
real $\eta-\eta'$ mixing angle $\theta_P$, a U(3)_V symmetry breaking scale
parameter c_W, and the radiative decay constants $F_\pi, F_K, F_\eta,
F_{\eta'}$, for the $\pi, \eta$, K, $\eta '$ mesons, respectively. Taking
$F_\pi = 93 MeV$, a global fit to decay width data yields F_K/F_\pi = 1.16 \pm
0.11,
  F_\eta/F_\pi = 1.14\pm 0.04, F_{\eta'}/F_\pi = 1.09 \pm 0.04, c_W = -0.19
\pm0.03, \theta_P =-(15.4 \pm 1.8)^o.


title:
Analysis of the low-energy $\eta$NN-dynamics within a three-body
  formalism

abstract:
  The interaction of an $\eta$-meson with two nucleons is studied within a
three-body approach. The major features of the $\eta NN$-system in the
low-energy region are accounted for by using a s-wave separable ansatz for the
two-body $\eta N$- and $NN$-amplitudes. The calculation is confined to the
$(J^\pi;T)=(0^-;1)$ and $(1^-;0)$ configurations which are assumed to be the
most promising candidates for virtual or resonant $\eta NN$-states. The
eigenvalue three-body equation is continued analytically into the nonphysical
sheets by contour deformation. The position of the poles of the three-body
scattering matrix as a function of the $\eta N$-interaction strength is
investigated. The corresponding trajectory, starting on the physical sheet,
moves around the $\eta NN$ three-body threshold and continues away from the
physical area giving rise to virtual $\eta NN$-states. The search for poles on
the nonphysical sheets adjacent directly to the upper rim of the real energy
axis gives a negative result. Thus no low-lying s-wave $\eta NN$-resonances
were found. The possible influence of virtual poles on the low-energy $\eta
NN$-scattering is discussed.


title:
On the Migdal-Watson approach to FSI effects in meson production in NN
  collisions

abstract:
  The influence of the nucleon-nucleon final state interaction (FSI) on
properties of the meson production amplitude near threshold is discussed. For
the nucleon-nucleon interaction a simple Yamaguchi potential as well as
realistic potential models are considered. It is shown that FSI effects cannot
be factorized from the production amplitude. The absolute magnitude of FSI
effects depends on the momentum transfer (or on the mass of the produced meson)
and hence is not universal. Only in the case of the production of rather heavy
mesons like eta' or phi FSI effects become universal. The Jost function
approach to FSI effects is critically examined.


title:
A simple model illustrating the impossibility of measuring off-shell
  effects

abstract:
  We consider a simple model and make use of field transformations in
Lagrangian field theories to illustrate the impossibility of measuring
off-shell effects in nucleon-nucleon bremsstrahlung and related processes.


title:
Influence of the Coulomb Interaction on the Chemical Equilibrium of
  Nuclear Systems at Break-Up

abstract:
  The importance of a Coulomb correction to the formalism proposed by Albergo
et al. for determining the temperatures of nuclear systems at break-up and the
ensities of free nucleon gases is discussed. While the proposed correction has
no effect on the temperatures extracted based on double isotope ratios, it
becomes non-negligible when such temperatures or densities of free nucleon
gases are extracted based on multiplicities of heavier fragments of different
atomic numbers.


title:
The Liquid-Gas Phase Transitions in a Multicomponent Nuclear System with
  Coulomb and Surface Effects

abstract:
  The liquid-gas phase transition is studied in a multi-component nuclear
system using a local Skyrme interaction with Coulomb and surface effects. Some
features are qualitatively the same as the results of Muller and Serot which
uses relativistic mean field without Coulomb and surface effects. Surface
tension brings the coexistance binodal surface to lower pressure. The Coulomb
interaction makes the binodal surface smaller and cause another pair of binodal
points at low pressure and large proton fraction with less protons in liquid
phase and more protons in gas phase.


title: Breit-Wigner to Gaussian transition in strength functions

abstract:
  Employing hamiltonians defined by two-body embedded Gaussian orthogonal
ensemble of random matrices(EGOE(2)) plus a mean-field producing one-body part,
strength functions (for states defined by the one-body part) are constructed
for various values of the strength of the chaos generating two-body part.
Numerical calculations for six and seven fermion systems clearly demonstrate
Breit-Wigner to Gaussian transition, in the chaotic domain, in strength
functions as found earlier in nuclear shell model and Lipkin-Meshkov-Glick
model calculations.


title: Near threshold Lambda and Sigma production in pp collisions

abstract:
  A model calculation for the reactions $pp\to p\Lambda K^+$ and $pp\to N\Sigma
K$ near their thresholds is presented. It is argued that the experimentally
observed strong suppression of $\Sigma^0$ production compared to $\Lambda$
production at the same excess energy could be due to a destructive interference
between the $\pi$ and $K$ exchange contributions in the reaction $pp\to
p\Sigma^0 K^+$. Predictions for $pp\to p\Sigma^+ K^0$ and $pp\to n\Sigma^+ K^+$
are given.


title: On a q-analogue of the spin-orbit coupling

abstract:
  Based on the tensor method, a q-analoque of the spin-orbit coupling is
introduced in a q-deformed Schroedinger equation, previously derived for a
central potential. Analytic expressions for the matrix elemnets of the
representation j=l\pm 1/2 are derived. The spectra of the harmonic oscillator
and the Coulomb potential are calculated numerically as a function of the
deformation parameter, without and with the spin-orbit coupling. The harmonic
oscillator spectrum presents strong analogies with the bound spectrum of an
Woods-Saxon potential customarily used in nuclear physics. The Coulomb spectrum
simulates relativistic effects. The addition of the spin-orbit coupling
reinforces this picture.


title: Nucleon Properties in the Covariant Quark-Diquark Model

abstract:
  In the covariant quark-diquark model the effective Bethe-Salpeter (BS)
equations for the nucleon and the $\Delta$ are solved including scalar {\em and
axialvector} diquark correlations. Their quark substructure is effectively
taken into account in both, the interaction kernel of the BS equations and the
currents employed to calculate nucleon observables. Electromagnetic current
conservation is maintained. The electric form factors of proton and neutron
match the data. Their magnetic moments improve considerably by including
axialvector diquarks and photon induced scalar-axialvector transitions. The
isoscalar magnetic moment can be reproduced, the isovector contribution is
about 15% too small. The ratio $\mu G_E/G_M$ and the axial and strong couplings
$g_A$, $g_{\pi NN}$, provide an upper bound on the relative importance of
axialvector diquarks confirming that scalar diquarks nevertheless describe the
dominant 2-quark correlations inside nucleons.


title: The GDH sum rule for the deuteron

abstract:
  As first topic, the GDH sume rule is discussed in the context of a more
general class of sum rules associated with the various contributions to the
total photoabsorption cross section for target and beam polarization. Then I
address the question of whether the GDH sum rule for the neutron can be
determined from the one for the deuteron. It appears that this will not be
possible in a simple manner. The spin response of the deuteron is calculated
including contributions from the photodisintegration channel and from coherent
and incoherent single pion production as well, and the GDH integral is
evaluated up to a photon energy of 550 MeV. The photodisintegration channel
converges fast enough and gives a large negative contribution, essentially from
the $^1S_0$ state near threshold and its absolute size is about the same than
the sum of proton and neutron GDH values. It is only partially cancelled by the
single pion production contribution. But the incoherent channel has not reached
convergence at 550 MeV.


title:
The Single State Dominance Hypothesis and the Two-Neutrino Double Beta
  Decay of Mo100

abstract:
  The hypothesis of the single state dominance (SSD) in the calculation of the
two-neutrino double beta decay of Mo100 is tested by exact consideration of the
energy denominators of the perturbation theory. Both transitions to the ground
state as well as to the 0+ and 2+ excited states of the final nucleus Ru100 are
considered. We demonstrate, that by experimental investigation of the single
electron energy distribution and the angular correlation of the outgoing
electrons, the SSD hypothesis can be confirmed or ruled out by a precise
two-neutrino double beta decay measurement (e.g. by NEMO III collaboration).


title: Complex Scaling of the Faddeev Operator

abstract:
  The work is devoted to comparison of two different approaches to calculation
of three-body resonances on the basis of the Faddeev differential equations.
The first one is the well known complex scaling approach. The second method is
based on an immediate calculation of the zeros of the scattering matrix
continued to the physical sheet.


title: Charm meson scattering cross sections by pion and rho meson

abstract:
  Using the local flavor SU(4) gauge invariance in the limit of vanishing
vector meson masses, we extend our previous study of charm meson scattering
cross sections by pion and rho meson, which is based only on the
pseudoscalar-pseudoscalar-vector meson couplings, to include also contributions
from the couplings among three vector mesons and among four particles. We find
that diagrams with light meson exchanges usually dominate the cross sections.
For the processes considered previously, the additional interactions lead only
to diagrams involving charm meson exchanges and contact interactions, and the
cross sections for these processes are thus not much affected. Nevertheless,
these additional interactions introduce new processes with light meson
exchanges and increase significantly the total scattering cross sections of
charm mesons by pion and rho meson.


title:
Fourth Order Algorithms for Solving the Multivariable Langevin Equation
  and the Kramers Equation

abstract:
  We develop a fourth order simulation algorithm for solving the stochastic
Langevin equation. The method consists of identifying solvable operators in the
Fokker-Planck equation, factorizing the evolution operator for small time steps
to fourth order and implementing the factorization process numerically. A key
contribution of this work is to show how certain double commutators in the
factorization process can be simulated in practice. The method is general,
applicable to the multivariable case, and systematic, with known procedures for
doing fourth order factorizations. The fourth order convergence of the
resulting algorithm allowed very large time steps to be used. In simulating the
Brownian dynamics of 121 Yukawa particles in two dimensions, the converged
result of a first order algorithm can be obtained by using time steps 50 times
as large. To further demostrate the versatility of our method, we derive two
new classes of fourth order algorithms for solving the simpler Kramers equation
without requiring the derivative of the force. The convergence of many fourth
order algorithms for solving this equation are compared.


title: Density fluctuations and multifragmentation of nuclear matter

abstract:
  The density fluctuations of nuclear matter are studied within a mean-field
model in wich fluctuations are generated by an external stochastic field. The
constraints imposed on the random force by the fluctuation-dissipation theorem
are analyzed. It is shown that in the proximity of the borders of the spinodal
region the assumption of a white-noise stochastic field can be reliably used.
The domain distribution of the liquid phase in the spinodal decomposition of
nuclear matter is derived. The related distribution of fragment sizes compares
favourably with the experimental fragment distribution observed in heavy ion
collisions.


title: Two pion electroproduction

abstract:
  We have extended a model for the $\gamma N\to \pi\pi N$ reaction to virtual
photons and selected the diagrams which have a $\Delta$ in the final state. The
agreement found with the $\gamma_v p\to\Delta^0\pi^+$ and $\gamma_v
p\to\Delta^{++}\pi^-$ reactions is good. The sensitivity of the results to
$N\Delta$ transition form factors is also studied. The present reaction,
selecting a particular final state, is an extra test for models of the
$\gamma_{v} N\to \pi\pi N$ amplitude.


title: J/psi suppression in ultrarelativistic nuclear collisions

abstract:
  Using a multiphase transport model, we study the relative importance of J/psi
suppression mechanisms due to plasma screening, gluon scattering, and hadron
absorption in heavy ion collisions at the Relativistic Heavy Ion Collider. We
find that for collisions between heavy nuclei such as Au+Au, both plasma
screening and gluon scattering are important. As a result, the effect due to
absorption by hadrons becomes relatively minor. The final J/psi survival
probability in these collisions is only a few percent. In the case of
collisions between light nuclei such as S+S, the effect of plasma screening is,
however, negligible in spite of the initial high parton density. The final
J/psi survival probability thus remains appreciable after comparable absorption
effects due to gluons and hadrons.


title: Probing nucleon strangeness in phi electroproduction

abstract:
  We investigate $\phi$ meson electroproduction to probe the hidden strangeness
content of the nucleon. We found that even a small amount of the $s\bar{s}$
admixture in the nucleon wavefunction can lead to a significant change in
several double polarization asymmetries in $\phi$ electroproduction, which can
be tested experimentally at current electron facilities.


title: Shadowing and Fragmentation in High-Energy Photo-Mesonproduction

abstract:
  A model for the description of photonuclear reactions in the multi-GeV range
is described that combines the coherent initial state interactions (shadowing)
of the incoming photon with an incoherent coupled channel description of final
state interactons of outgoing particles. Particle production itself is treated
either, at low energies, through nucleon resonance decays or, at higher
energies, through string fragmentation. The initial state nucleons can be
far-off-shell due to ground state correlations. Results are shown for
semi-inclusive meson production.


title:
Relevant polarization observables for the study of the Roper resonance
  with hadronic probes

abstract:
  The purpose of this contribution is to stress the great importance of
polarization observables for the study of nucleon resonances, in particular in
the case of deuteron and proton probes. Polarization observables play a unique
role in signing the reaction mechanism and bring new information in the
microscopic description of baryon resonances. We will calculate the relevant
polarization observables, for $p+d$- and $p+\alpha$-collisions, in case of
inclusive reactions and for some selected exclusive channels.


title: Phenomenological Evidence for Gluon Depletion in pA Collisions

abstract:
  The data of J/psi suppression at large x_F in pA collisions are used to infer
the existence of gluon depletion as the projectile proton traverses the
nucleus. The modification of the gluon distribution is studied by use of a
convolution equation whose non-perturbative splitting function is determined
phenomenologically. The depletion factor at x_1=0.8 is found to be about 25% at
A=100.


title: Why N*'s are Important

abstract:
  The study of N*'s can provide us with critical insights into the nature of
QCD in the confinement domain. The keys to progress in this domain are the
identification of its important degrees of freedom and the effective forces
between them. I report on the growing evidence in support of the flux tube
model, and comment on the connection between this model and spontaneous chiral
symmetry breaking, on the spin-dependence of the long-range confining
potential, on the evidence for short-range one gluon exchange, on instantons,
and on the one pion exchange model.


title: Variations on the Deuteron

abstract:
  We consider few problems which are related to the deuteron and have simple
analytical solution. Relation is found between the deuteron electric quadrupole
moment and the $np$-scattering amplitude. The degree of circular polarization
of photons is calculated for the radiative capture of longitudinally polarized
thermal neutrons. The anapole, electric dipole and magnetic quadrupole moments
of the deuteron are calculated.


title: Calculating the Fierz Transformation for Higher Orders

abstract:
  We consider the higher-order Fierz transformation, which corresponds to
expanding a product of $\bar\psi\Gamma\psi$ terms into a sum of products of
Dirac densities and currents. It is shown that the Fierz transformation can be
obtained by solving a large system of linear equations with fractional complex
coefficients, which is practical at least up to fourth power.


title: Photons from Ultra-Relativistic Heavy Ion Collisions

abstract:
  It is believed that a novel state of matter - Quark Gluon Plasma (QGP) will
be transiently produced if normal hadronic matter is subjected to sufficiently
high temperature and/or density. We have investigated the possibility of QGP
formation in the ultra-relativistic collisions of heavy ions through the
electromagnetic probes - photons and dileptons. The formulation of the real and
virtual photon production rate from strongly interacting matter is studied in
the framework of Thermal Field Theory. Since signals from the QGP will pick up
large backgrounds from hadronic matter we have performed a detailed study of
the changes in the hadronic properties induced by temperature within the ambit
of the Quantum Hadrodynamic model, gauged linear and non-linear sigma models,
hidden local symmetry approach and QCD sum rule approach. The possibility of
observing the direct thermal photons and lepton pairs from quark gluon plasma
has been contrasted with that from hot hadronic matter with and without medium
effects for various mass variation scenarios. The effects of medium induced
modifications have also been incorporated in the evolution dynamics through the
equation of state. We find that the in-medium effects on the hadronic
properties in the framework of the Quantum Hadrodynamic model, Brown-Rho
scaling and Nambu scaling scenarios are conspicuously visible through the low
invariant mass distribution of dileptons and transverse momentum spectra of
photons. We have compared our evaluation of the photon and dilepton spectra
with experimental data obtained by the WA80, WA98 and CERES Collaborations in
the heavy ion experiments performed at the CERN SPS. Predictions of
electromagnetic spectra for RHIC energies have also been made.


title: Nucleon form factors in the canonically quantized Skyrme model

abstract:
  The explicit expressions for the electric, magnetic, axial and induced
pseudoscalar form factors of the nucleons are derived in the {\it ab initio}
quantized Skyrme model. The canonical quantization procedure ensures the
existence of stable soliton solutions with good quantum numbers. The form
factors are derived for representations of arbitrary dimension of the SU(2)
group. After fixing the two parameters of the model, $f_\pi$ and $e$, by the
empirical mass and electric mean square radius of the proton, the calculated
electric and magnetic form factors are fairly close to the empirical ones,
whereas the the axial and induced pseudoscalar form factors fall off too slowly
with momentum transfer.


title: Spin Structure of Many-Body Systems with Two-Body Random Interactions

abstract:
  We investigate the spin structure of many-fermion systems with a
spin-conserving two-body random interaction. We find a strong dominance of
spin-0 ground states and considerable correlations between energies and wave
functions of low-lying states with different spin, but no indication of
pairing. The spectral densities exhibit spin-dependent shapes and widths, and
depend on the relative strengths of the spin-0 and spin-1 couplings in the
two-body random matrix. The spin structure of low-lying states can largely be
explained analytically.


title:
Perspectives of scalar- and vector-meson production in hadron-nucleus
  reactions

abstract:
  The production and decay of vector mesons ($\rho, \omega$) in $pA$ reactions
at COSY energies is studied with particular emphasis on their in-medium
spectral functions. It is explored within transport calculations, if hadronic
in-medium decays like $\pi^+\pi^-$ or $\pi^0 \gamma$ might provide
complementary information to their dilepton ($e^+e^-$) decays. Whereas the
$\pi^+ \pi^-$ signal from the $\rho$-meson is found to be strongly distorted by
pion rescattering, the $\omega$-meson Dalitz decay to $\pi^0 \gamma$ appears
promising even for more heavy nuclei. The perspectives of scalar meson ($f_0,
a_0$) production in $pp$ reactions are investigated within a boson-exchange
model indicating that the $f_0$-meson might hardly be detected in these
collisions in the $K \bar{K}$ or $\pi \pi$ decay channels whereas the exclusive
channel $pp \to d a_0^+$ looks very promising.


title: Spin polarisabilities of the nucleon at NLO in the chiral expansion

abstract:
  We present a calculation of the fourth-order (NLO) contribution to
spin-dependent Compton scattering in heavy-baryon chiral perturbation theory,
and we give results for the four spin polarisabilities. These results have been
presented before, in hep-ph/0002133. Here we address the issue of whether
one-particle reducible graphs in the heavy baryon theory contribute to the
polarisabilities.


title: Extra dimensions, SN1987a, and nucleon-nucleon scattering data

abstract:
  One of the strongest constraints on the existence of large, compact,
"gravity-only" dimensions comes from SN1987a. If the rate of energy loss into
these putative extra dimensions is too high, then the neutrino pulse from the
supernova will differ from that actually seen. The dominant mechanism for the
production of Kaluza-Klein gravitons and dilatons in the supernova is via
gravistrahlung and dilastrahlung from the nucleon-nucleon system. In this paper
we compute the rates for these processes in a model-independent way using
low-energy theorems which relate the emissivities to the measured
nucleon-nucleon cross section. This is possible because for soft gravitons and
dilatons the leading contribution to the energy-loss rate is from graphs in
which the gravitational radiation is produced from external nucleon legs.
Previous calculations neglected these mechanisms. We re-evaluate the bounds on
toroidally-compactified "gravity-only" dimensions (GODs), and find that
consistency with the observed SN1987a neutrino signal requires that if there
are two such dimensions then their radius must be less than 1 micron.


title: Simultaneous Heavy Ion Dissociation at Ultrarelativistic Energies

abstract:
  We study the simultaneous dissociation of heavy ultrarelativistic nuclei
followed by the forward-backward neutron emission in peripheral collisions at
colliders. The main contribution to this particular heavy-ion dissociation
process, which can be used as a beam luminosity monitor, is expected to be due
to the electromagnetic interaction. The Weizsacker-Williams method is extended
to the case of simultaneous excitation of collision partners which is simulated
by the RELDIS code. A contribution to the dissociation cross section due to
grazing nuclear interactions is estimated within the abrasion model and found
to be relatively small.


title: The Love-Hate Relationship Between the Shell Model and Cluster Models

abstract:
  We adopt a personal approach here reviewing several calculations over the
years in which we have experienced confrontations between cluster models and
the shell model. In previous cluster conferences we have noted that cluster
models go hand in hand with Skyrme Hartee-Fock calculations in describing
states which cannot easily, if at all, be handled by the shell model. These are
the highly deformed (many particle - many hole) intruder states, linear chain
states e.t.c. In the present work we will consider several topics; the
quadrupole moment of $^{6}$Li, the non-existence of low lying intruders in
$^{8}$Be, and then jumping to the $f_{7/2}$ shell, we discuss the two-faceted
nature of the nuclei - sometimes displaying shell model properties, other times
cluster properties.


title: Thermal and chemical equilibration of hadronic matter

abstract:
  We study thermal and chemical equilibration in 'infinite' hadron matter as
well as in finite size relativistic nucleus-nucleus collisions using a BUU
cascade transport model with resonance and string degrees-of-freedom. The
'infinite' hadron matter is simulated within a cubic box employing periodic
boundary conditions. The various equilibration times depend on baryon density
and energy density and are much shorter for particles consisting of light
quarks then for particles including strangeness. For kaons and antikaons the
chemical equilibration time is found to be larger than $\simeq$ 40 fm/c for all
baryon and energy densities considered. The inclusion of continuum excitations,
i.e. hadron 'strings', leads to a limiting temperature of $T_s\simeq$ 150 MeV.


title:
Transverse energy fluctuations and the pattern of J/Psi suppression in
  Pb-Pb collisions

abstract:
  The NA50 collaboration has recently observed that the J/psi production rate
in Pb-Pb collisions decreases more rapidly as a function of the transverse
energy for the most central collisions than for less central ones. We show that
this phenomenon can be understood as an effect of transverse energy
fluctuations in central collisions. A good fit of the data is obtained using a
model which relates J/psi suppression to the local energy density. Our results
suggest that the J/psi is completely suppressed at the highest densities
achieved in Pb-Pb collisions.


title: Kaon Condensation in High Density Quark Matter

abstract:
  We point out that the problem of kaon condensation in dense hadronic matter
can be addressed in perturbative QCD. Indeed, perturbative calculations suggest
that negative kaons are condensed in high density quark matter if the
electroweak interaction is taken into account. This observation sheds new light
on the proposal that the low density hyperon and high density quark phase of
QCD are continuously connected.


title:
Classifying Reported and "Missing" Resonances According to Their P and C
  Properties

abstract:
  The Hilbert space H^3q of the three quarks with one excited quark is
decomposed into Lorentz group representations. It is shown that the quantum
numbers of the reported and ``missing'' resonances fall apart and populate
distinct representations that differ by their parity or/and charge conjugation
properties. In this way, reported and ``missing'' resonances become
distinguishable. For example, resonances from the full listing reported by the
Particle Data Group are accommodated by Rarita-Schwinger (RS) type
representations (k/2,k/2)*[(1/2,0)+(0,1/2)] with k=1,3, and 5, the highest spin
states being J=3/2^-, 7/2^+, and 11/2^+, respectively. In contrast to this,
most of the ``missing'' resonances fall into the opposite parity RS fields of
highest-spins 5/2^-, 5/2^+, and 9/2^+, respectively. Rarita-Schwinger fields
with physical resonances as lower-spin components can be treated as a whole
without imposing auxiliary conditions on them. Such fields do not suffer the
Velo-Zwanziger problem but propagate causally in the presence of
electromagnetic fields. The pathologies associated with RS fields arise
basically because of the attempt to use them to describe isolated spin-J=k+1/ 2
states, rather than multispin-parity clusters. The positions of the observed RS
clusters and their spacing are well explained trough the interplay between the
rotational-like (k/2)(k/2 +1)-rule and a Balmer-like -(k+1)^{-2}-behavior.


title: Effective Field Theory in Nuclear Physics

abstract:
  I review recent developments in the application of effective field theory to
nuclear physics. Emphasis is placed on precision two-body calculations and
efforts to formulate the nuclear shell model in terms of an effective field
theory.


title:
Inclusive quasielastic electron scattering on $^6$He: a probe of the
  halo structure

abstract:
  We investigate inclusive electron scattering reactions on two-neutron halo
nuclei in the quasielastic region. Expressions for the cross section and
structure functions are given assuming that the halo nucleus can be described
as a three-body system (${core}+n+n$). The method is applied to $^6$He. We
compute cross sections and structure functions, and investigate the kinematic
conditions for which the observables are determined either by $\alpha$-knockout
or by halo neutron-knockout. The optimal kinematical domain to disantangle the
momentum distributions of the various components of the three--body system ($q
\lesssim 200$ MeV/c and $\omega < q^2/2M_N + 20$ MeV) are explored.


title:
Meson-Meson Scattering in the Quark Model: Spin Dependence and Exotic
  Channels

abstract:
  We apply a quark interchange model to spin-dependent and exotic meson-meson
scattering. The model includes the complete set of standard quark model forces,
including OGE spin-orbit and tensor and scalar confinement spin-orbit.
Scattering amplitudes derived assuming SHO and Coulomb plus linear plus
hyperfine meson wavefunctions are compared. In I=2 pi pi we find approximate
agreement with the S-wave phase shift from threshold to 1.5 GeV, where we
predict an extremum that is supported by the data. Near threshold we find rapid
energy dependence that may reconcile theoretical estimates of small scattering
lengths with experimental indications of larger ones based on extrapolation of
measurements at moderate kpi^2. In PsV scattering we find that the quark-quark
L*S and T forces map into L*S and T meson-meson interactions, and the P-wave
L*S force is large. Finally we consider scattering in J^PC-exotic channels, and
note that some of the Deck effect mechanisms suggested as possible nonresonant
origins of the pi_1(1400) signal are not viable in this model.


title: Anomalous radial expansion in central heavy-ion reactions

abstract:
  The expansion velocity profile in central heavy-ion reactions in the Fermi
energy domain is examined. The radial expansion is non-hubblean and in the
surface region it scales proportional to a higher exponent ($\alpha > 1$) of
the radius. The anomalous expansion velocity profile is accompanied by a power
law nucleon density profile in the surface region. Both these features of
central heavy-ion reactions disappear at higher energies, and the system
follows a uniform Hubble expansion ($\alpha \simeq 1$).


title: $\Upsilon$ absorption in hadronic matter

abstract:
  The cross sections of $\Upsilon$ absorption by $\pi$ and $\rho$ mesons are
evaluated in a meson-exchange model. Including form factors with a cutoff
parameter of 1 or 2 GeV, we find that due to the large threshold of these
reactions the thermal average of their cross sections is only about 0.2 mb at a
temperature of 150 MeV. Our results thus suggest that the absorption of
directly produced $\Upsilon$ by hadronic comovers in high energy heavy ion
collisions is unimportant.


title: Anharmonic double-phonon excitations in the interacting boson model

abstract:
  Double-$\gamma$ vibrations in deformed nuclei are analyzed in the context of
the interacting boson model. A simple extension of the original version of the
model towards higher-order interactions is required to explain the observed
anharmonicities of nuclear vibrations. The influence of three- and four-body
interactions on the moments of inertia of ground- and $\gamma$-bands, and on
the relative position of single-$\gamma$ and double-$\gamma$ bands is studied
in detail. As an example of a realistic calculation, spectra and transitions of
the highly $\gamma$-anharmonic nuclei $^{164}$Dy, $^{166}$Er, and $^{168}$Er
are interpreted in this approach.


title: Saturation of low-energy antiproton annihilation on nuclei

abstract:
  Recent measurements of very low-energy ($p_{L}<100$ MeV/c) $\bar p$
annihilation on light nuclei reveal apparent suppression of annihilation upon
increasing the atomic charge $Z$ and mass number $A$. Using $\bar p$-nucleus
optical potentials $V_{{\rm opt}}$, fitted to $\bar p$-atom energy-shifts and
-widths, we resolve this suppression as due to the strong effective repulsion
produced by the very absorptive $V_{{\rm opt}}$. The low-energy $\bar
p$-nucleus wavefunction is kept substantially outside the nuclear surface and
the resulting reaction cross section saturates as function of the strength of
Im $V_{{\rm opt}}$. This feature, for $E >0$, parallels the recent prediction,
for $E < 0$, that the level widths of $\bar p$ atoms saturate and, hence, that
$\bar p$ deeply bound atomic states are relatively narrow. Antiproton
annihilation cross sections are calculated at $p_{L}=57$ MeV/c across the
periodic table, and their dependence on $Z$ and $A$ is classified and discussed
with respect to the Coulomb focussing effect at very low energies.


title: Chiral Phase Transition within Effective Models with Constituent Quarks

abstract:
  We investigate the chiral phase transition at nonzero temperature $T$ and
baryon-chemical potential $\mu_B$ within the framework of the linear sigma
model and the Nambu-Jona-Lasinio model. For small bare quark masses we find in
both models a smooth crossover transition for nonzero $T$ and $\mu_B=0$ and a
first order transition for T=0 and nonzero $\mu_B$. We calculate explicitly the
first order phase transition line and spinodal lines in the $(T,\mu_B)$ plane.
As expected they all end in a critical point. We find that, in the linear sigma
model, the sigma mass goes to zero at the critical point. This is in contrast
to the NJL model, where the sigma mass, as defined in the random phase
approximation, does not vanish. We also compute the adiabatic lines in the
$(T,\mu_B)$ plane. Within the models studied here, the critical point does not
serve as a ``focusing'' point in the adiabatic expansion.


title: Local and non-local equivalent potentials for p-12C scattering

abstract:
  A Newton-Sabatier fixed energy inversion scheme has been used to equate
inherently non-local p-${}^{12}$C potentials at a variety of energies to pion
threshold, with exactly phase equivalent local ones. Those energy dependent
local potentials then have been recast in the form of non-local Frahn-Lemmer
interactions.


title: Hadron structure after 25 years of QCD

abstract:
  We briefly review the status of our understanding of hadron structure based
on QCD. This includes the role of symmetries, especially chiral symmetry, and
the insights provided by lattice QCD. The main focus is on baryon structure and
especially the nucleon, but this cannot be treated realistically without
reference to spectroscopy. Our aim is to highlight recent insights and
promising directions for future work.


title: Critical Review Of Quark Gluon Plasma Signals

abstract:
  Compelling evidence for a new form of matter has been claimed to be formed in
Pb+Pb collisions at SPS. We critically review two suggested signatures for this
new state of matter: First the suppression of the J/$\Psi$, which should be
strongly suppressed in the QGP by two different mechanisms, the color-screening
and the QCD-photoeffect. Secondly the measured particle, in particular strange
hadronic, ratios might signal the freeze-out from a quark-gluon phase.


title:
Annual Report for the Department of Energy: 1999-2000, Nuclear Theory
  Group at the University of Washington

abstract:
  This document is a summary of the physics research carried out by the Nuclear
Theory Group at the University of Washington during the last twelve-month
period, 1999-2000.


title: Shell model description of "mixed-symmetry" states in 94Mo

abstract:
  Shell model calculations have been performed for the nucleus 94Mo. The
calculated excitation energies and electromagnetic properties of low-lying
states are in good agreement with the data, which include states with
mixed-symmetry (MS) assignments in previous interacting boson model studies. In
the shell model large isoscalar E2 matrix elements are found between states
with MS assignments indicating that they form a class of states with similar
proton-neutron symmetry.


title:
Influence of nucleonic motion in Relativistic Fermi Gas inclusive
  responses

abstract:
  Impulsive hadronic descriptions of electroweak processes in nuclei involve
two distinctly different elements: one stems from the nuclear many-body physics
--- the medium --- which is rather similar for the various inclusive response
functions, and the other embodies the responses of the hadrons themselves to
the electroweak probe and varies with the channel selected. In this letter we
investigate within the context of the relativistic Fermi gas in both the
quasi-elastic and $N\to\Delta$ regimes the interplay between these two
elements. Specifically, we focus on expansions in the one small parameter in
the problem, namely, the momentum of a nucleon in the initial wave function
compared with the hadronic scale, the nucleon mass. Both parity-conserving and
-violating inclusive responses are studied and the interplay between
longitudinal ($L$) and transverse ($T$ and $T'$) contributions is highlighted.


title:
Lepton U_l(1) symmetry and interaction of neutrinos with deuterons at
  high energies

abstract:
  The following items are discussed: 1. The lepton U_l(1) symmetry and its
relation to the presence of the neutrino mass term in the Hamiltonian. 2. The
possibility of the measurement of the neutrino-deuteron reactions with high
energy neutrinos at SNO by using neutrinos from a neutrino factory. 3. The weak
axial one-boson exchange currents for the Bethe-Salpeter equation.


title:
Microscopic dynamics of a phase transition: equilibrium vs
  out-of-equilibrium regime

abstract:
  We present for the first time to the nuclear physics community the
Hamiltonian Mean Field (HMF) model. The model can be solved analytically in the
canonical ensemble and shows a second-order phase transition in the
thermodynamic limit. Numerical microcanonical simulations show interesting
features in the out-of-equilibrium regime: in particular the model has a
negative specific heat. The potential relevance for nuclear multifragmentation
is discussed.


title: Correlated model for quasi-elastic responses in finite nuclear systems

abstract:
  A model to calculate nuclear responses considering short-range correlation
effects is presented. The model is applied to the study of electromagnetic
responses induced by one-body operators. We calculate one- and two-nucleon
emission responses and cross sections of the 16O and 40Ca nuclei in the
quasi-elastic region, and we compare them with experimental data.


title:
Dynamical calculation of $d^*$ mass and NN decay width in the quark
  delocalization, color screening model

abstract:
  The mass estimate of the $d^* (IJ^P=03^+)$ dibaryon is improved by a
dynamical calculation in the quark delocalization, color screening model. The
partial decay width of $d^*$ into an $NN$ D-wave state is also obtained. The
mass obtained is slightly larger than that obtained in adiabatic calculations,
due to the anharmonicity of the effective potential between two $\Delta$'s. The
value of the width obtained due to tensor one-gluon-exchange is about 5 MeV,
comparable in magnitude to earlier results found using pion exchange.


title:
Large Nuclear shape transition at finite temperature in a relativistic
  mean field approach

abstract:
  The relativistic Hartree-BCS theory is applied to study the temperature
dependence of nuclear shape and pairing gap for $^{166}Er$ and $^{170}Er$. For
both the nuclei, we find that as temperature increases the pairing gap vanishes
leading to phase transition from superfluid to normal phase as is observed in
nonrelativistic calculation. The deformation evolves from prolate shapes to
spherical shapes at $T\sim 2.7$ MeV. Comparison of our results for heat
capacity with the ones obtained in the non-relativistic mean field framework
indicates that in the relativistic mean field theory the shape transition
occurs at a temperature about 0.9 MeV higher and is relatively weaker. The
effect of thermal shape fluctuations on the temperature dependence of
deformation is also studied. Relevant results for the level density parameter
are further presented.
  PACS numbers: 21.10.Ma, 21.60.-n, 27.70.+q


title: Partial wave contributions to the antikaon potential at finite momentum

abstract:
  The momentum dependence of the antikaon optical potential in nuclear matter
is obtained from a microscopic and self-consistent calculation using the
meson-exchange J\"ulich $\bar{K}N$ interaction. Two self-consistent schemes are
discussed, which would lead to substantially different predictions for the
width of ${\bar K}$ nuclear bound states. The effect of higher partial waves of
the $\bar{K}N$ interaction, beyond the L=0 component, is studied and found to
have moderate but non-negligible effects on the ${\bar K}$ nuclear potential at
zero momentum. At momenta as large as 500 MeV/c, relevant in the analysis of
heavy-ion collisions, the higher partial partial waves modify the ${\bar K}$
optical potential by nearly a factor of two.


title:
On the Observation of Phase Transitions in Collisions of Elementary
  Matter

abstract:
  We investigate the excitation function of directed flow, which can provide a
clear signature of the creation of the QGP and demonstrate that the minimum of
the directed flow does not correspond to the softest point of the EoS for
isentropic expansion. A novel technique measuring the compactness is introduced
to determine the QGP transition in relativistic-heavy ion collisions: The QGP
transition will lead to higher compression and therefore to higher compactness
of the source in coordinate space. This effect can be observed by pion
interferometry. We propose to measure the compactness of the source in the
appropriate principal axis frame of the compactness tensor in coordinate space.


title:
Theoretical description of deformed proton emitters: nonadiabatic
  coupled-channel method

abstract:
  The newly developed nonadiabatic method based on the coupled-channel
Schroedinger equation with Gamow states is used to study the phenomenon of
proton radioactivity. The new method, adopting the weak coupling regime of the
particle-plus-rotor model, allows for the inclusion of excitations in the
daughter nucleus. This can lead to rather different predictions for lifetimes
and branching ratios as compared to the standard adiabatic approximation
corresponding to the strong coupling scheme. Calculations are performed for
several experimentally seen, non-spherical nuclei beyond the proton dripline.
By comparing theory and experiment, we are able to characterize the angular
momentum content of the observed narrow resonance.


title: On the origin of order from random two-body interactions

abstract:
  We investigate the origin of order in the low-lying spectra of many-body
systems with random two-body interactions. Contrary to the common belief our
study based both on analytical as well as on numerical arguments shows that
these are the higher $J$-sectors whose ground states are more orderly than the
ones in the J=0-sector. A predominance of J=0 ground states turns out to be the
result of putting on together states with different characteristic energy
scales from different $J$-sectors.


title:
Signatures of Quark-Gluon Plasma Phase Transition in High-Energy Nuclear
  Collisions

abstract:
  In high-energy nuclear collisions, the new phase of the quark-gluon plasma is
indicated by an anomalous increase in pressure, an excess of direct photon
production, an excess of strangeness production, and an anomalous J/psi
suppression. We review these signatures and discuss how recent high-energy
heavy-ion experiments at CERN are consistent with the production of the
quark-gluon plasma in high-energy Pb+Pb collisions.


title: Relativistic nuclear structure effects in (e,e' vec{p})

abstract:
  Results for recoil nucleon induced polarization for $(e,e'\vec{p})$ are
presented using various approximations for the relativistic nucleonic current,
at the kinematics of a recent experiment at Bates. We see that the dynamical
relativistic effects improve the agreement with the data. We make predictions
for the induced normal polarization and responses for TJNAF 89-033 and Mainz
A1/2-93 experiments.


title:
Observable measures of critical behavior in high-energy nuclear
  collisions

abstract:
  Critical behaviors of quark-hadron phase transition in high-energy heavy-ion
collisions are investigated with the aim of identifying hadronic observables.
The surface of the plasma cylinder is mapped onto a 2D lattice. The Ising model
is used to simulate configurations corresponding to cross-over transitions in
accordance to the findings of QCD lattice gauge theory. Hadrons are formed in
clusters of all sizes. Various measures are examined to quantify the
fluctuations of the cluster sizes and of the voids among the clusters. The
canonical power-law behaviors near the critical temperature are found for
appropriately chosen measures. Since the temperature is not directly
observable, attention is given to the problem of finding observable measures.
It is demonstrated that for the measures considered the dependence on the
final-state randomization is weak. Thus the critical behavior of the measures
proposed is likely to survive the scattering effect of the hadron gas in the
final state.


title:
Hanbury Brown-Ttiss Correlation Functions from Event Generators: A
  Reliable Approach to Determine the Size of the Emitting Source in
  Ultrarelativistic Heavy Ion Collisions?

abstract:
  Employing NEXUS, one of the most recent simulation programs for heavy ions
collisions, we investigate in detail the Hanbury-Twiss correlation function for
charged pions for reactions 158 GeV Pb+Pb. For this study we supplement the
standard simulation program by electromagnetic interactions. We find that the
string fragmentation introduces strong space-momentum correlations and the
freeze out times of the correlated pairs have a wide distribution. Both has a
strong influence on the apparent source radius determined from the measured
correlation correlation function.An equally strong influence is observed for
the final state electromagnetic interaction.


title:
Density dependent hadron field theory for asymmetric nuclear matter and
  exotic nuclei

abstract:
  The density dependent relativistic hadron field (DDRH) theory is applied to
strongly asymmetric nuclear matter and finite nuclei far off stability. A new
set of in-medium meson-nucleon vertices is derived from Dirac-Brueckner
Hartree-Fock (DBHF) calculations in asymmetric matter, now accounting also for
the density dependence of isovector coupling constants. The scalar-isovector
$\delta$ meson is included. Nuclear matter calculations show that it is
necessary to introduce a momentum correction in the extraction of coupling
constants from the DBHF self-energies in order to reproduce the DBHF equation
of state by DDRH mean-field calculations. The properties of DDRH vertices
derived from the Groningen and the Bonn A nucleon-nucleon (NN) potentials are
compared in nuclear matter calculations and for finite nuclei. Relativistic
Hartree results for binding energies, charge radii, separation energies and
shell gaps for the Ni and Sn isotopic chains are presented. Using the momentum
corrected vertices an overall agreement to data on a level of a few percent is
obtained. In the accessible range of asymmetries the $\delta$ meson
contributions to the self-energies are found to be of minor importance but
asymmetry dependent fluctuations may occur.


title: Nucleon-nucleon interaction in the Skyrme model

abstract:
  We consider the interaction of two skyrmions in the framework of the sudden
approximation. The widely used product ansatz is investigated. Its failure in
reproducing an attractive central potential is associated with terms that
violate G-parity. We discuss the construction of alternative ans\"atze and
identify a plausible solution to the problem.


title: Coupling of Dipole Mode to gamma-unstable Quadrupole Oscillations

abstract:
  The coupling of the high-lying dipole mode to the low-lying quadrupole modes
for the case of deformed gamma-unstable nuclei is studied. Results from the
geometrical model are compared to those obtained within the dipole boson model.
Consistent results are obtained in both models. The dipole boson model is
treated within the intrinsic frame, with subsequent projection onto the
laboratory frame. As an application, calculations of photonuclear
cross-sections in gamma-unstable nuclei are presented.


title:
On the different role of protons and neutrons in antinucleon
  annihilations on nuclei

abstract:
  We compare data of antineutron and antiproton annihilation cross sections on
different targets at very low energies. After subtracting Coulomb effects, we
observe that the ratio between the antineutron proton and antiproton proton
annihilation cross sections is an oscillating function of the energy at momenta
smaller 300 MeV/c. This nontrivial behavior is confirmed by the analysis of the
relative number of antiproton-neutron and antiproton-proton annihilations in
nuclei. We show that a part of the strong shadowing phenomena in
antiproton-nucleus annihilations can be explained in terms of this oscillation,
while a part requires different explainations.


title: Continuum Strong QCD: Confinement and Dynamical Chiral Symmetry Breaking

abstract:
  Continuum strong QCD is the application of models and continuum quantum field
theory to the study of phenomena in hadronic physics, which includes; e.g., the
spectrum of QCD bound states and their interactions. Herein I provide a
Dyson-Schwinger equation perspective, focusing on qualitative aspects of
confinement and dynamical chiral symmetry breaking in cold, sparse QCD, and
also elucidating consequences of the axial-vector Ward-Takahashi identity and
features of the heavy-quark limit.


title:
Relativistic Quark Spin Coupling Effects in the Correlations Between
  Nucleon Electroweak Properties

abstract:
  We investigate the effect of different relativistic spin couplings of
constituent quarks on nucleon electroweak properties. Within each quark spin
coupling scheme the correlations between static electroweak observables are
found to be independent of the particular shape of the momentum part of the
nucleon light-front wave function. The neutron charge form factor is very
sensitive to different choices of spin coupling schemes once the magnetic
moment is fitted to the experimental value. However, it is found rather
insensitive to the details of the momentum part of the three-quark wave
function model.


title: Partial Dynamical Symmetries in Nuclei

abstract:
  Partial dynamical symmetries (PDS) are shown to be relevant to the
interpretation of the $K=0_2$ band and to the occurrence of F-spin multiplets
of ground and scissors bands in deformed nuclei. Hamiltonians with bosonic and
fermionic PDS are presented.


title: The three- and four-nucleon systems from chiral effective field theory

abstract:
  Recently developed chiral nucleon-nucleon (NN) forces at next-to-leading
order (NLO) that describe NN phase shifts up to about 100 MeV fairly well have
been applied to 3N and 4N systems. Faddeev-Yakubovsky equations have been
solved rigorously. The chiral NLO forces depend on a momentum cut-off \Lambda
lying between 540-600 MeV/c. The resulting 3N and 4N binding energies are in
the same range as found using standard NN potentials. In additon, low-energy 3N
scattering observables are very well reproduced like for standard NN forces.
Surprisingly, the long standing A_y-puzzle is resolved at NLO. The cut-off
dependence of the scattering observables is rather mild.


title:
Lattice QCD Calculations of Hadron Structure: Constituent Quarks and
  Chiral Symmetry

abstract:
  New data from parity-violating experiments on the deuteron now allow
isolation of the strange-quark contribution to the nucleon magnetic moment,
G_M^s(0), without the uncertainty surrounding the anapole moment of the
nucleon. Still, best estimates place G_M^s(0) > 0. It is illustrated how this
experimental result challenges the very cornerstone of the constituent quark
model. The chiral physics giving rise to G_M^s(0) \sim 0 is illustrated.


title:
(Non)Thermal Aspects of Charmonium Production and a New Look at J/$\psi$
  Suppression

abstract:
  To investigate a recent proposal that J/$\psi$ production in
ultra-relativistic nuclear collisions is of thermal origin we have reanalyzed
the data from the NA38/50 collaboration within a thermal model including charm.
Comparison of the calculated with measured yields demonstrates the non-thermal
origin of hidden charm production at SPS energy. However, the ratio
$\psi^{'}$/(J/$\psi)$ exhibits, in central nucleus-nucleus collisions, thermal
features which lead us to a new interpretation of open charm and charmonium
production at SPS energy. Implications for RHIC and LHC energy measurements
will be discussed.


title:
Effective Field Theories, Landau-Migdal Fermi-Liquid Theory and
  Effective Chiral Lagrangians for Nuclear Matter

abstract:
  We reinterpret Landau-Migdal Fermi-liquid theory of nuclear matter as an
effective chiral field theory with a Fermi surface. The effective field theory
is formulated in terms of a chiral Lagrangian with its {\it mass and coupling
parameters} scaling a la Brown-Rho and with the Landau-Migdal parameters
identified as the fixed points of the field theory. We show how this mapping
works out for response functions to the EM vector current and then using the
same reasoning, make prediction on nuclear axial current, in particular on the
enhanced axial-charge transitions in heavy nuclei. We speculate on how to
extrapolate the resulting theory which appears to be sound both theoretically
and empirically up to normal nuclear matter density $\rho_0$, to hitherto
unexplored higher density regime relevant to relativistic heavy-ion processes
and to cold compact (neutron) stars.


title: Effective interactions in medium heavy nuclei

abstract:
  We present a brief overview of microscopic nuclear structure approaches to
nuclei with mass number from 100 to 132. The emphasis is on the shell model and
theories for deriving effective interactions starting from the free
interactions between nucleons. New results for (105,106,107)Sb are presented.


title:
Exact Solution of the Statistical Multifragmentation Model and
  Liquid-Gas Phase Transition in Nuclear Matter

abstract:
  An exact analytical solution of the statistical multifragmentation model is
found in thermodynamic limit. The system of nuclear fragments exhibits a 1-st
order liquid-gas phase transition. The peculiar thermodynamic properties of the
model near the boundary between the mixed phase and the pure gaseous phase are
studied.


title:
New method for measuring azimuthal distributions in nucleus-nucleus
  collisions

abstract:
  The methods currently used to measure azimuthal distributions of particles in
heavy ion collisions assume that all azimuthal correlations between particles
result from their correlation with the reaction plane. However, other
correlations exist, and it is safe to neglect them only if azimuthal
anisotropies are much larger than 1/sqrt(N), with N the total number of
particles emitted in the collision. This condition is not satisfied at
ultrarelativistic energies. We propose a new method, based on a cumulant
expansion of multiparticle azimuthal correlations, which allows to measure much
smaller values of azimuthal anisotropies, down to 1/N. It is simple to
implement and can be used to measure both integrated and differential flow.
Furthermore, this method automatically eliminates the major systematic errors,
which are due to azimuthal asymmetries in the detector acceptance.


title: Universal trend of the information entropy of a fermion in a mean field

abstract:
  We calculate the information entropy of single-particle states in
position-space $S_{r}$ and momentum-space $S_{k}$ for a nucleon in a nucleus, a
$\Lambda$ particle in a hypernucleus and an electron in an atomic cluster. It
is seen that $S_{r}$ and $S_{k}$ obey the same approximate functional form as
functions of the number of particles, $S_{r}$ ({\rm or} $S_{k}) = a+bN^{1/3}$
in all of the above many-body systems in position- and momentum- space
separately. The net information content $S_{r}+S_{k}$ is a slowly varying
function of $N$ of the same form as above. The entropy sum $S_{r}+S_{k}$ is
invariant to uniform scaling of coordinates and a characteristic of the
single-particle states of a specific system. The order of single-particle
states according to $S_r +S_k$ is the same as their classification according to
energy keeping the quantum number $n$ constant. The spin-orbit splitting is
reproduced correctly. It is also seen that $S_{r}+S_{k}$ enhances with
excitation of a fermion in a quantum-mechanical system. Finally, we establish a
relationship of $S_r +S_k$ with the energy of the corresponding single-particle
state i.e. $S_r +S_k = k \ln (\mu E +\nu)$. This relation holds for all the
systems under consideration.


title: Collective Evolution of Hot QCD Matter from the QGP to Freeze-Out

abstract:
  We present results on the evolution of <p_t> with energy, for hadrons
emerging from hadronization of a quark-gluon plasma possibly produced in
high-energy heavy-ion collisions. We find that BNL-RHIC energy corresponds to
the previously predicted plateau of <p_t>, reminiscent of the assumed
first-order QCD phase transition. Heavy hadrons are the best messengers of the
transverse flow stall.


title:
Mean field studies of high-spin properties in the $A\sim 30$ and 60
  regions of superdeformation

abstract:
  The importance of deformation changes and the possible role of proton-neutron
pairing correlations on the properties of paired band crossings at
superdeformation in the $A\sim 60$ mass region have been analyzed. The present
analysis, supported in part by the cranked relativistic Hartree-Bogoliubov
calculations for the SD band in $^{60}$Zn, suggests that when going from
$^{60}$Zn to neighboring odd nuclei the properties of paired band crossings are
strongly influenced by deformation changes. A number of questions related to
the superdeformation in the $A\sim 30$ mass region has been studied with the
cranked relativistic mean field theory and the configuration-dependent cranked
Nilsson-Strutinsky approach.


title:
Nuclear equation of state at high density and the properties of neutron
  stars

abstract:
  We discuss the relativistic nuclear equation of state (EOS) using a
relativistic transport model in heavy-ion collisions. From the baryon flow for
$Au + Au$ systems at SIS to AGS energies and above we find that the strength of
the vector potential has to be reduced moderately at high density or at high
relative momenta to describe the flow data at 1-10 A GeV. We use the same
dynamical model to calculate the nuclear EOS and then employ this to calculate
the gross structure of the neutron star considering the core to be composed of
neutrons with an admixture of protons, electrons, muons, sigmas and lambdas at
zero temperature. We then discuss these gross properties of neutron stars such
as maximum mass and radius in contrast to the observational values.


title: SU(2) Chiral sigma model and the properties of neutron stars

abstract:
  We discuss the {\it SU}(2) chiral sigma model in the context of nuclear
matter using a mean field approach at high density. In this model we include a
dynamically generated isoscalar vector field and higher-order terms in the
scalar field. With the inclusion of these, we reproduce the empirical values of
the nuclear matter saturation density, binding energy, and nuclear
incompressibility. The value of the incompressibility is chosen according to
recently obtained heavy-ion collision data. We then apply the same dynamical
model to neutron-rich matter in beta equilibrium, related to neutron star
structure. The maximum mass and corresponding radius of stable non-rotating
neutron stars are found to be in the observational limit.


title:
Microscopic substructure effects in potential-model descriptions of the
  $^7$Be$(p,\gamma)^8$B reaction

abstract:
  The spectroscopic factor arises from short-range effects in the nuclear wave
function. On the other hand, cross sections for external capture reactions,
such as $^7$Be$(p,\gamma)^8$B at low energies, depend primarily on the
asymptotic normalization of the bound-state wave function -- a long-range
property. We investigate the relationship between potential models and the full
many-body problem to illustrate how microscopic substructure effects arise
naturally in the relevant transition matrix element and can be (in part)
accounted for by a spectroscopic factor.


title: Prediction of nuclear reaction rates for astrophysics

abstract:
  This is an overview over the prediction of astrophysical reaction rates in
the statistical model, with special emphasis on the parametrization of optical
alpha+nucleus potentials.