title: Baryon Number Fluctuation and the Quark-Gluon Plasma

abstract:
  We show that $\omega_B$ or $\omega_{\bar B}$, the squared baryon or
antibaryon number fluctuation per baryon or antibaryon, is a possible signature
for the quark-gluon plasma that is expected to be created in relativistic heavy
ion collisions, as it is a factor of three smaller than in an equilibrated
hadronic matter due to the fractional baryon number of quarks. Using kinetic
equations with exact baryon number conservation, we find that their values in
an equilibrated matter are half of those expected from a Poisson distribution.
Effects due to finite acceptance and non-zero net baryon number are also
studied.


title: Total Routhian surface calculations for neutron-rich 149Ce

abstract:
  Total Routhian Surface (TRS) calculations were performed for the 149Ce
nucleus. The equilibrium deformation parameters and total angular momentum
values have been calculated as a function of rotational frequency for both
signatures of the lowest positive- and negative-parity rotational bands.
Theoretical predictions are compared with the results of experimental studies
of this nucleus.


title: Plasma production and thermalisation in a strong field

abstract:
  Aspects of the formation and equilibration of a quark-gluon plasma are
explored using a quantum kinetic equation, which involves a non-Markovian,
Abelian source term for quark and antiquark production and, for the collision
term, a relaxation time approximation that defines a time-dependent
quasi-equilibrium temperature and collective velocity. The strong Abelian field
is determined via the simultaneous solution of Maxwell's equation. A particular
feature of this approach is the appearance of plasma oscillations in all
thermodynamic observables. Their presence can lead to a sharp increase in the
time-integrated dilepton yield.


title: Is the collective IBM space exhausted only by the valence shell?

abstract:
  Interpretation of the B(E2) values at energies higher the first backbending
indicates that the maximum boson of IBM has to increase with energy and spin.


title:
Statistical Multifragmentation in Thermodynamical Limit: An Exact
  Solution for Phase Transitions

abstract:
  An exact analytical solution of the statistical multifragmentation model is
found in thermodynamic limit. Excluded volume effects are taken into account in
the thermodynamically self-consistent way. The model exhibits a 1-st order
phase transition of the liquid-gas type. An extension of the model including
the Fisher's term is also studied. The possibility of the second order phase
transition at or above the critical point is discussed. The mixed phase region
of the phase diagram, where the gas of nuclear fragments coexists with the
infinite liquid condensate, is unambiguously identified. The peculiar
thermodynamic properties of the model near the boundary between the mixed phase
and the pure gaseous phase are studied. The results for the caloric curve and
specific heat are presented and a physical picture of the nuclear liquid-gas
phase transition is clarified.


title: The QCD Mixed Phase: Shaken, not Stirred

abstract:
  Baryon fluctuations exceeding Poisson expectations can signal a nearly first
order phase transition at RHIC. We show how these fluctuations can be measured,
and apply a dissipative-hydrodynamic formulation used in condensed matter
physics to simulate their evolution.


title: Quadrupole collectivity in Si isotopes around N=20

abstract:
  The angular momentum projected Generator Coordinate Method using the
quadrupole moment as collective coordinate and the Gogny force as the effective
interaction is used to describe the properties of the ground state and
low-lying excited states of the neutron rich light nuclei 32,34,36Si. It is
found that the ground state of the nucleus 34Si is spherical. However, this is
not only due to the N=20 shell closure as the ground state of 34Si contains a
significant amount of the intruder f7/2 neutron orbital. On the other hand,
rather good agreement with experimental data for many observables is obtained.


title:
Towards explanation of the "inertia anomalies" in realistic mean field
  calculations

abstract:
  Careful theoretical studies of the nuclear collective inertia based on the
non-relativistic mean-field theory and the cranking model indicate that the
moments of inertia of the super-deformed nuclei calculated using various
standard methods and parameterizations exceed systematically the experimental
values. Similarly, but for other reasons the relativistic cranking calculations
based on the relativistic mean field method present, in our opinion, a
different class of systematic deviations from experiment. The origin and
possible explanations of these deviations are discussed briefly.


title:
A novel scenario for the production of antihyperons in relativistic
  heavy ion collisions

abstract:
  We elaborate on our recent suggestion on antihyperon production in
relativistic heavy ion collisions by means of multi-mesonic (fusion-type)
reactions. It will be shown that the (rare) antihyperons are driven towards
chemical equilibrium with pions, nucleons and kaons on a timescale of 1--3 fm/c
in a still moderately baryon-dense hadronic environment.


title: Hadronic degrees of freedom

abstract:
  I report on the research activities performed under the (italian) MURST-PRIN
project "Fisica Teorica del Nucleo e dei sistemi a pi\'u corpi" covering part
of the topics on hadronic degrees of freedom. The most recent achievements in
the field are summarized focusing on the specific role of the nuclear physics
community.


title:
a0(980)-f0(980) mixing and isospin violation in the reactions pN -> d
  a0, pd -> 3He/3H a0 and dd -> 4He a0

abstract:
  It is demonstrated that f_0-a_0 mixing can lead to a comparatively large
isospin violation in the reactions pN -> da_0, pd -> ^3He/^3H a_0 and dd ->
^4He a_0 close to the corresponding production thresholds. The observation of
such mixing effects is possible, e.g., by measuring the forward-backward
asymmetry in the reaction pn -> d a_0^0 -> d eta pi^0.


title:
Medium effects in the production and pi0 gamma decay of omega-mesons in
  pA collisions in the GeV region

abstract:
  The omega-resonance production and its pi0 gamma decay in p-A reactions close
to threshold is considered within the Intranuclear Cascade (INC) Model. The pi0
gamma invariant mass distribution shows two components which correspond to the
omega decay 'inside' and 'outside' the nucleus, respectively. The 'inside'
component is distorted by medium effects, which introduce a mass shift as well
as collisional broadening for the omega-meson and its decaying pion. The
relative contribution of the 'inside' component is analyzed in detail for
different kinematical conditions and nuclear targets. It is demonstrated that a
measurement of the correlation in azimuthal angle between the pi0 and gamma
momenta allows to separate events related to the 'inside' omega decay from
different sources of background when uncorrelated pi0's and gamma's are
produced.


title: J/Psi suppression in central Pb-Pb collisions

abstract:
  We discuss the recent NA50 J/Psi production data in Pb--Pb collisions, in
particular the second drop at high transverse energies which correspond to the
most central collisions. Using a model which relates the J/Psi suppression to
the local energy density, we show that the data can be explained by taking into
account transverse energy fluctuations at a given impact parameter. Predictions
of this model for RHIC are briefly discussed.


title: Event-by-event fluctuations and the QGP

abstract:
  We discuss the physics underlying event-by-event fluctuations in relativistic
heavy ion collisions. We will emphasize how the fluctuations of particle ratios
can be utilized to explore the properties of the matter created in these
collisions. In particular, we will argue that the fluctutions of the ratio of
positively over negatively charged particles may serve as a unique signature
for the Quark Gluon Plasma.


title: On Properties of the Isoscalar Giant Dipole Resonance

abstract:
  Main properties (strength function, energy-dependent transition density,
branching ratios for direct nucleon decay) of the isoscalar giant dipole
resonance in several medium-heavy mass spherical nuclei are described within a
continuum-RPA approach, taking into account the smearing effect. All model
parameters used in the calculations are taken from independent data.
Calculation results are compared with available experimental data.


title: The Ay Problem for p-3He Elastic Scattering

abstract:
  We present evidence that numerically accurate quantum calculations employing
modern internucleon forces do not reproduce the proton analyzing power, A_y,
for p-3He elastic scattering at low energies. These calculations underpredict
new measured analyzing powers by approximately 30% at E_{c.m.} = 1.20 MeV and
by 40% at E_{c.m.} = 1.69 MeV, an effect analogous to a well-known problem in
p-d and n-d scattering. The calculations are performed using the complex Kohn
variational principle and the (correlated) Hyperspherical Harmonics technique
with full treatment of the Coulomb force. The inclusion of the three-nucleon
interaction does not improve the agreement with the experimental data.


title:
Tables of Nuclear Cross Sections and Reaction Rates: an Addendum to the
  Paper "Astrophysical Reaction Rates from Statistical Model Calculations"

abstract:
  In a previous publication [Atomic Data and Nuclear Data Tables 75, 1 (2000)],
we had given seven parameter analytical fits to theoretical reaction rates
derived from nuclear cross sections calculated in the statistical model
(Hauser-Feshbach formalism) for targets with 9<Z<84 (Ne to Bi) and for a mass
range reaching the neutron and proton driplines. Reactions considered were
(n,gamma), (n,p), (n,alpha), (p,gamma), (p,alpha), (alpha,gamma), and their
inverse reactions. On public demand, we present here the theoretical nuclear
cross sections and astrophysical reaction rates from which those rate fits were
derived, and we provide these data as on-line electronic files. Corresponding
to the fitted rates, two complete data sets are provided, one of which includes
a phenomenological treatment of shell quenching for neutron-rich nuclei.


title: J/psi suppression at SPS and RHIC in the comovers approach

abstract:
  The NA50 collaboration data on the $J/\psi$ suppression are compared with the
results obtained in a comovers approach based on the Dual Parton Model (DPM).
Predictions for the $J/\psi$ suppression versus the charged multiplicity -
measured in the rapidity region of the dimuon trigger - are given for SPS and
RHIC energies.


title:
Comment on `Two-body random ensembles: from nuclear spectra to random
  polynomials

abstract:
  In PRL 85, 3773 (2000) it was suggested to use random polynomials to analyze
and understand the properties of two-body random ensembles. In this comment we
point out that for the vibron model the random polynomial is not quadratic, but
has a more general form. We make a comparison for the percentage of ground
states with L=0 in the vibron model with random interactions.


title: Relativistic Calculations for Incoherent Photoproduction of Eta Mesons

abstract:
  We develop a relativistic model for incoherent eta-photoproduction on nuclei.
The elementary process is described using an effective Lagrangian containing
photons, nucleons, the S11(1535) and D13(1520) nucleon resonances, and rho,
omega, and eta mesons. The nucleon and eta wavefunctions are obtained from
relativistic wave equations. Final-state interactions of the outgoing particles
are included via optical potentials. The effects of these interactions are
found to be large and lead to reduced cross sections.The incoherent cross
sections for isovector transitions are much larger than those for isoscalar
ones. The dominant contributions are those from the S11 and D13 resonances. We
find important interference effects between the contributions of these two
resonances. We give some detailed calculations for the cross sections for
incoherent eta-photoproduction on C-12. We find that the incoherent cross
section for a subset of states in the excitation energy region below 17 MeV are
significantly larger than those of the coherent process. These cross sections
may thus be accessible experimentally.


title: Memory effects on descent from nuclear fission barrier

abstract:
  Non-Markovian transport equations for nuclear large amplitude motion are
derived from the collisional kinetic equation. The memory effects are caused by
the Fermi surface distortions and depend on the relaxation time. It is shown
that the nuclear collective motion and the nuclear fission are influenced
strongly by the memory effects at the relaxation time $\tau \geq 5\cdot
10^{-23}{\rm s}$. In particular, the descent of the nucleus from the fission
barrier is accompanied by characteristic shape oscillations. The eigenfrequency
and the damping of the shape oscillations depend on the contribution of the
memory integral in the equations of motion. The shape oscillations disappear at
the short relaxation time regime at $\tau \to 0$, which corresponds to the
usual Markovian motion in the presence of friction forces. We show that the
elastic forces produced by the memory integral lead to a significant delay for
the descent of the nucleus from the barrier. Numerical calculations for the
nucleus $^{236}$U shows that due to the memory effect the saddle-to-scission
time grows by a factor of about 3 with respect to the corresponding
saddle-to-scission time obtained in liquid drop model calculations with
friction forces.


title: Sound modes in hot nuclear matter

abstract:
  The propagation of the isoscalar and isovector sound modes in a hot nuclear
matter is considered. The approach is based on the collisional kinetic theory
and takes into account the temperature and memory effects. It is shown that the
sound velocity and the attenuation coefficient are significantly influenced by
the Fermi surface distortion (FSD). The corresponding influence is much
stronger for the isoscalar mode than for the isovector one. The memory effects
cause a non-monotonous behavior of the attenuation coefficient as a function of
the relaxation time leading to a zero-to-first sound transition with increasing
temperature. The mixing of both the isoscalar and the isovector sound modes in
an asymmetric nuclear matter is evaluated. The condition for the bulk
instability and the instability growth rate in the presence of the memory
effects is studied. It is shown that both the FSD and the relaxation processes
lead to a shift of the maximum of the instability growth rate to the longer
wave length region.


title:
QRPA plus Phonon Coupling Model and the Photoabsorbtion Cross Section
  for $^{18,20,22}$O

abstract:
  We have calculated the electric dipole strength distributions in the unstable
neutron rich oxygen isotopes $^{18,20,22}$O, in a model which include up to
four quasi-particle-type configurations. The model is the extension, to include
the effect of the pairing correlations, of a previous model very successful
around closed shell nuclei, and it is based on the quasi-particle-phonon
coupling. Low-lying dipole strength is found, which exhausts between 5 and 10%
of the Thomas-Reiche-Kuhn (TRK) energy-weighted-sum-rule (EWSR) below 15 MeV
excitation energy, in rather good agreement with recent experimental data. The
role of the phonon coupling is shown to be crucial in order to obtain this
result.


title: Search for magnetic rotation in the A~140 region

abstract:
  Magnetic dipole bands have been identified in 142,143,144Gd and 141Eu nuclei.
The observed bands are based on configurations with small oblate deformation
involving high-Omega, h11/2 proton particles and low-Omega, h11/2 neutron
holes. Information about the strength of the effective interaction between the
constituent nucleons has been deduced using a semiclassical scheme of the
coupling of two angular momentum vectors. The experimental results are compared
with predictions of tilted axis cranking calculations. The transition from
irregular dipole band in 144Gd to more regular ones in lighter Gd nuclei is
observed.


title:
Incoherent Photoproduction of $\eta$-mesons from the Deuteron near
  Threshold

abstract:
  Incoherent photoproduction of the $\eta$-meson on the deuteron is studied for
photon energies from threshold to 800 MeV. The dominant contribution, the
$\gamma$N-$\eta$N amplitude, is described within an isobar model. The final
state interaction derived from the CD-Bonn potential is included and found to
be important for the description of the production cross section close to
threshold. Possible effects from the $\eta N$ final state interaction are
discussed.


title: Fast Rotation of the N=Z Nucleus 36Ar

abstract:
  A highly-deformed rotational band has been identified in the N=Z nucleus
36Ar. At high spin the band is observed to its presumed termination at I=16+,
while at low spin it has been firmly linked to previously known states in 36Ar.
Spins, parities, and absolute excitation energies have thus been determined
throughout the band. Lifetime measurements establish a large low-spin
quadrupole deformation (beta_2=0.46+-0.03) and indicate a decreasing
collectivity as the band termination is approached. With effectively complete
spectroscopic information and a valence space large enough for significant
collectivity to develop, yet small enough to be meaningfully approached from
the shell model perspective, this rotational band in 36Ar provides many
exciting opportunities to test and compare complementary models of collective
motion in nuclei.


title: Equation of state and phase transitions in asymmetric nuclear matter

abstract:
  The structure of the 3-dimension pressure-temperature-asymmetry surface of
equilibrium of the asymmetric nuclear matter is studied within the thermal
Thomas-Fermi approximation. Special attention is paid to the difference of the
asymmetry parameter between the boiling sheet and that of the condensation
sheet of the surface of equilibrium. We derive the condition of existence of
the regime of retrograde condensation at the boiling of the asymmetric nuclear
matter. We have performed calculations of the caloric curves in the case of
isobaric heating. We have shown the presence of the plateau region in caloric
curves at the isobaric heating of the asymmetric nuclear matter. The shape of
the caloric curve depends on the pressure and is sensitive to the value of the
asymmetry parameter. We point out that the experimental value of the plateau
temperature T \approx 7 MeV corresponds to the pressure P = 0.01 MeV/fm^3 at
the isobaric boiling.


title: Coulomb excitation at ultra-relativistic energies

abstract:
  In previous studies of the theory of Coulomb excitation, the term in the
electromagnetic interaction which is quadratic in the vector potential has been
ignored. In this paper, we use qualitative arguments and detailed numerical
calculations to show that this quadratic term must be included when the
bombarding energy is in excess of about 20 GeV per nucleon.


title:
Cranking in isospace - towards a consistent mean-field description of
  N=Z nuclei

abstract:
  Excitation spectra of T=0,1,2 states in even-even (e-e) and odd-odd (o-o) N=Z
nuclei are analyzed within a mean-field based model involving isovector and
isoscalar pairing interactions and the iso-cranking formalism applied to
restore approximately isospin symmetry. It is shown that T=0 states in o-o and
T=1 states in e-e nuclei correspond to two-quasiparticle, time-reversal
symmetry breaking excitations since their angular momenta are different than
zero. On the other hand the lowest T=2 states in e-e and T=1 states in o-o
nuclei, which both are similar in structure to their even-even isobaric
analogue states, are described as e-e type vaccua excited (iso-cranked) in
isospace. It appears that in all cases isoscalar pairing plays a crucial role
in restoring the proper value of the inertia parameter in isospace.


title:
Model-independent analysis of the neutron-proton final-state interaction
  region in the pp -> pn pi^+ reaction

abstract:
  Experimental data on the pp -> pn pi^+ reaction measured in an exclusive
two-arm experiment at 800 MeV show a narrow peak arising from the strong
proton-neutron final-state interaction. It was claimed, within the framework of
a certain model, that this peak contained up to a 25% spin-singlet final state
contribution. By comparing the data with those of pp -> d pi^+ in a largely
model-independent way, it is here demonstrated that at all the angles measured
the whole of the peak could be explained as being due to spin-triplet final
states, with the spin-singlet being at most a few percent. Good qualitative
agreement with the measured proton analysing power is also found within this
approach.


title: Neutrino absortion cross sections in supernova environment

abstract:
  We study charged-current neutrino cross sections on neutronrich nuclei in the
mass $A\sim60$ region. Special attention is paid to environmental effects, i.e.
finite temperature and density, on the cross sections. As these effects are
largest for small neutrino energies, it is sufficient to study only the
Gamow-Teller (GT) contributions to the cross sections. The relevant GT strength
distributions are derived from large-scale shell model calculations. We find
that the low-energy cross sections are enhanced at finite temperatures.
However, for $(\nu_e,e^-)$ reactions Pauli blocking of the electrons in the
final state makes the cross sections for low-energy neutrinos much smaller than
for the competing inelastic scattering on electrons at moderate and large
densities. Absorption cross sections for low-energy antineutrinos are strongly
enhanced at finite temperatures.


title: Elliptic flow and freezeout from the parton cascade MPC

abstract:
  Differential elliptic flow out to p_T ~ 5 GeV/c and particle spectra are
calculated using the MPC elastic parton cascade model for Au+Au at Ecm ~ 130A
GeV. The evolution is computed from parton transport theory, followed by
hadronization either via independent fragmentation or by imposing parton-hadron
duality. With pQCD elastic cross sections, very large initial gluon densities
dN/deta > 7000 are required to reproduce the data measured by the STAR
collaboration. In addition, elliptic flow and the p_T spectra are shown to be
very sensit ive to particle subdivision.


title: Void Analysis of Hadronic Density Fluctuations at Phase Transition

abstract:
  The event-to-event fluctuations of hadron multiplicities are studied for a
quark system undergoing second-order phase transition to hadrons. Emphasis is
placed on the search for an observable signature that is realistic for
heavy-ion collisions. It is suggested that in the 2-dimensional y-phi space the
produced particles selected in a very narrow p_T window may exhibit clustering
patterns even when integrated over the entire emission time. Using the Ising
model to simulate the critical phenomenon and taking into account a p_T
distribution that depends on the emission time, we study in the framework of
the void analysis proposed earlier and find scaling behavior. The scaling
exponents turn out to be larger than the ones found before for pure
configurations without mixing. The signature is robust in that it is
insensitive to the precise scheme of simulating time evolution. Thus it should
reveal whether or not the dense matter created in heavy-ion collisions is a
quark-gluon plasma before hadronization.


title: Is there elliptic flow without transverse flow?

abstract:
  Azimuthal anisotropy of final particle distributions was originally
introduced as a signature of transverse collective flow. We show that finite
anisotropy in momentum space can result solely from the shape of the particle
emitting source. However, by comparing the differential anisotropy to recent
data from STAR collaboration we can exclude such a scenario, but instead show
that the data favour strong flow as resulting from a hydrodynamical evolution.


title: Multiple scattering and $p_t$-broadening at RHIC energies

abstract:
  In ultrarelativistic heavy-ion collisions, in the 2 GeV$<p_\perp<$ 6 GeV
transverse momentum region, the soft and semi-hard multiple scattering of the
incoming nucleons in the nuclear medium results in the broadening of the
expected hadronic (e.g. pion) $p_\perp$ spectra relative to proton-proton
($pp$) collisions. Thus, higher transverse-momentum regions are populated than
in $pp$ collisions. In a perturbative QCD based calculation we include the
intrinsic transverse momentum ($k_\perp$) of the partons in the nucleon
(determined from $pp$ collisions), augmented by the extra broadening obtained
via a systematic analysis of proton-nucleus ($pA$) collisions in the energy
range 17$<\sqrt{s}<$ 39 AGeV. The original polynomial spectra are modified, and
a nearly exponential spectrum appears in the region 2$\lesssim p_\perp\lesssim
3.5$ GeV. At present RHIC energies ($\sqrt{s}=$130 AGeV), the slope of the
calculated spectra is reminiscent of that of fluid-dynamical descriptions, but
lacks any thermal origin. We determine and discuss the size of the
modifications originating in multiple scattering, which lead to this state of
affairs.


title: Broad Band Equilibration of Strangeness

abstract:
  We develop the "broad band equilibration" scenario for kaon productions at
GSI energies with in-medium effects.


title:
Chemical freeze-out parameters at RHIC from microscopic model
  calculations

abstract:
  The relaxation of hot nuclear matter to an equilibrated state in the central
zone of heavy-ion collisions at energies from AGS to RHIC is studied within the
microscopic UrQMD model. It is found that the system reaches the
(quasi)equilibrium stage for the period of 10-15 fm/$c$. Within this time the
matter in the cell expands nearly isentropically with the entropy to baryon
ratio $S/A = 150 - 170$. Thermodynamic characteristics of the system at AGS and
at SPS energies at the endpoints of this stage are very close to the parameters
of chemical and thermal freeze-out extracted from the thermal fit to
experimental data. Predictions are made for the full RHIC energy $\sqrt{s} =
200$ AGeV. The formation of a resonance-rich state at RHIC energies is
discussed.


title: On the fourth P_11 resonance predicted by the constituent quark model

abstract:
  We point out a distinguishing difference between constituent quark models
based on one-gluon exchange and one-boson exchange dynamics. In the latter one,
the P_11 nucleon resonance with predominantly symmetrical spatial wave function
in the N=4 band gets strongly attracted such that it drops below some states in
the N=2 band. Calculations of strong decay widths are presented in order to
establish an identification with experimental states. Our results are relevant
for the interpretation of the fourth P_11 resonance that was found in the
partial wave analysis of the Zagreb group and recently discussed by Capstick
et. al. in the framework of a model based on one-gluon exchange.


title: Revealing Nuclear Pions Using Electron Scattering

abstract:
  A model for the pionic components of nuclear wave functions is obtained from
light front dynamical calculations of binding energies and densities. The
pionic effects are small enough to be consistent with measured nuclear di-muon
production data and with the nucleon sea. But the pion effects are large enough
to predict substantial nuclear enhancement of the cross section for
longitudinally polarized virtual photons for the kinematics accessible at
Jefferson Laboratory.


title: Atomic Parity Nonconservation and Nuclear Anapole Moments

abstract:
  Anapole moments are parity-odd, time-reversal-even moments of the E1
projection of the electromagnetic current. Although it was recognized, soon
after the discovery of parity violation in the weak interaction, that
elementary particles and composite systems like nuclei must have anapole
moments, it proved difficult to isolate this weak radiative correction. The
first successful measurement, an extraction of the nuclear anapole moment of
133Cs from the hyperfine dependence of the atomic parity violation, was
obtained only recently. An important anapole moment bound in Tl also exists. We
discuss these measurements and their significance as tests of the hadronic weak
interaction, focusing on the mechanisms that operate within the nucleus to
generate the anapole moment. The atomic results place new constraints on weak
meson-nucleon couplings, ones we compare to existing bounds from a variety of
p-p and nuclear tests of parity nonconservation.


title: Nucleon-Nucleon Scattering in a Three-Dimensional Approach

abstract:
  The nucleon-nucleon t-matrix is calculated directly as function of two vector
momenta for different realistic NN potentials. The angular and momentum
dependence of the full amplitude is studied and NN observables are calculated.


title: Update on Partial-Wave Analysis

abstract:
  Partial-wave analysis is one step in a process connecting experimental
measurements to the N* states we are studying. Progress has been made in the
area of `model-independent' analysis. However, more model-dependent approaches
are needed to cover broader energy ranges. An example of the problems faced by
these more ambitious analyses is given.


title:
Properties of $\rho$ and $\omega$ Mesons at Finite Temperature and
  Density as Inferred from Experiment

abstract:
  The mass shift, width broadening, and spectral density for the $\rho$ and
$\omega$ mesons in a heat bath of nucleons and pions are calculated using a
general formula which relates the self-energy to the real and imaginary parts
of the forward scattering amplitude. We use experimental data to saturate the
scattering amplitude at low energies with resonances and include a background
Pomeron term, while at high energies a Regge parameterization is used. The real
part obtained directly is compared with the result of a dispersion integral
over the imaginary part. The peaks of the spectral densities are little shifted
from their vacuum positions, but the widths are considerably increased due to
collisional broadening. Where possible we compare with the UrQMD model and find
quite good agreement. At normal nuclear matter density and a temperature of 150
MeV the spectral density of the $\rho$ meson has a width of 345 MeV, while that
for the $\omega$ is in the range 90--150 MeV.


title: Towards a Perturbative Theory of Nuclear Forces

abstract:
  We show that an expansion of nuclear forces about the chiral limit is
formally consistent and is equivalent to KSW power counting in the 1S0 channel
and Weinberg power counting in the 3S1-3D1 coupled channels. Numerical evidence
suggests that this expansion converges. The feasibility of making contact
between nuclear physics and lattice-QCD simulations is discussed.


title:
Interplay of soft and hard processes and hadron $p_T$ spectra in $pA$
  and $AA$ collisions

abstract:
  Motivated by a schematic model of multiple parton scattering within the
Glauber formalism, the transverse momentum spectra in $pA$ and $AA$ collisions
are analyzed in terms of a nuclear modification factor with respect to $pp$
collisions. The existing data at the CERN Super Proton Synchrotron (SPS)
energies are shown to be consistent with the picture of Glauber multiple
scattering in which the interplay between soft and hard processes and the
effect of absorptive processes lead to nontrivial nuclear modification of the
particle spectra. Relative to the additive model of incoherent hard scattering,
the spectra are enhanced at large $p_T$ (hard) by multiple scattering while
suppressed at low $p_T$ (soft) by absorptive correction with the transition
occurring at around a scale $p_0\sim 1-2$ GeV/$c$ that separates soft and hard
processes. Around the same scale, the $p_T$ spectra in $pp$ collisions also
change from an exponential form at low $p_T$ to a power-law behavior at high
$p_T$. At very large $p_T\gg p_0$, the nuclear enhancement is shown to decrease
like $1/p_T^2$. Implications of these nuclear effects on the study of jet
quenching, parton thermalization and collective radial flow in high-energy $AA$
collisions are discussed.


title: The $\eta NN$-system at low energy within a three-body approach

abstract:
  The role of the $\eta NN$-interaction is studied in the low energy regime in
$\eta$-deuteron reactions as well as in coherent and incoherent
$\eta$-photoproduction on the deuteron using a three-body model with separable
two-body interactions. The three-body approach turns out to be quite essential
in the most important lowest partial wave. Results are presented for
differential and total cross sections as well as for the $\eta$-meson spectrum.
They differ significantly from those predicted by a simple rescattering model
in which only first-order $\eta N$- and $NN$-interactions in the final state
are considered. The major features of the experimental data of
$\eta$-photoproduction in the near-threshold region are well reproduced.


title: Limit distributions of many-particle spectra

abstract:
  We find the limit distributions for a spectrum of a system of n particles
governed by a k-body interaction. The hamiltonian of this system is modelled by
a Gaussian random matrix.
  We show that the limit distribution is a q-deformed Gaussian distribution
with the deformation parameter q depending on the value of the fraction
\frac{k}{\sqrt{n}}. The family of q-deformed Gaussian distributions include the
Gaussian distribution and the semicircular law; therefore our result is a
generalization of the results of Wigner, Mon and French.


title: Gamma-ray strength functions in thermally excited rotating nuclei

abstract:
  A general discussion and illustration is given of strength functions for
rotational transitions in two-dimensional E(gamma_1) x E(gamma_2) spectra.
Especially, a narrow component should be proportional to the compound damping
width, related to the mixing of basis rotational bands into compound bands with
fragmented transition strength. Three E(gamma_1) x E(gamma_2) spectra are made
by setting gates on triple coincidences, selecting cascades which feed into
specific low-lying bands in the nucleus 168Hf. In each of the gated spectra, we
find a ridge, carrying about 100 decay paths. This ridge is ascribed to
rotational transitions in the excitation energy range of 1.0 to 1.5 MeV above
the yrast line. The FWHM of the ridges are around 40 keV, about a factor of two
smaller than calculated on the basis of mixed cranked mean field bands.


title:
Discovery of Jet Quenching at RHIC and the Opacity of the Produced Gluon
  Plasma

abstract:
  The predicted quenching of jets in A+A at RHIC energies has been discovered
by STAR and PHENIX in preliminary data reported at this conference. We apply
the GLV theory of QCD radiative energy loss to estimate the opacity,
L/\lambda_g, of the gluon plasma produced in Au+Au collisions at 130 AGeV. We
show that (in contrast to the factor of two Cronin enhancement of \pi^0 found
at the SPS by WA98) the factor of 5-8 suppression of p_T \sim 2-4 GeV \pi^0
reported by PHENIX can be accounted for with an effective static plasma opacity
L/\lambda_g \approx 3-4.


title: Fast nuclear rotation and octupole deformation

abstract:
  The 150Sm nucleus has been studied to high spins in a measurement of gamma
radiation following the 136Xe(18O,4n)150Sm, compound-nucleus reaction at beam
energy of 76 MeV. The measurement was performed at NBI Riso using the NORDBALL
array. Alternating parity, s=+1 band in 150Sm has been observed up to spin
I=22. This band is crossed by two aligned bands, corresponding to a
reflection-symmetric shape. After the second crossing the s=+1 band ends
abruptly, suggesting that the octupole shape vanishes in 150Sm above spin I=22,
as predicted by calculations. Other explanations, assuming continuation of the
s=+1 band past the two alignments are also discussed.


title: The Effect of Nuclear Rotation on the Collective Transport Coefficients

abstract:
  We have examined the influence of rotation on the potential energy and the
transport coefficients of the collective motion (friction and mass
coefficients). For axially symmetric deformation of nucleus Th-224 we have
found that at excitations corresponding to temperatures T > 1 MeV the shell
correction to the liquid drop energy practically does not depend on the angular
rotation. The friction and mass coefficients obtained within the linear
response theory for the same nucleus at temperatures larger than T=2 MeV are
rather stable with respect to rotation provided that the contributions from
spurious states arising due to the violation of rotation symmetry are removed.
At smaller excitations both friction and mass parameters corresponding to the
elongation mode are growing functions of rotational frequency.


title:
The importance of the nucleon-nucleon correlations for the eta alpha
  S-wave scattering length, and the pi-eta mixing angle in the low-energy eta
  alpha scattering length model

abstract:
  Using the new set of dd --> eta alpha near threshold experimental data, the
estimate of the importance of the nucleon-nucleon correlations for the eta
alpha S-wave scattering length in the multiple scattering theory is obtained
using the low-energy scattering length model. The contribution turns out to be
much bigger then previously believed. The pi-eta mixing angle is extracted
using the experimental data on the dd --> eta alpha and dd --> pi alpha
processes. The model is dominated by the subthreshold extrapolation recipe for
the eta alpha scattering amplitudes. When the recipe is chosen the model is
completely insensitive to the eta alpha parameters for the subthreshold value
of the eta cm momentum of p_{eta}^2 = -(0.46)^2 fm^{-2}. Provided that the
subthreshold extrapolation recipe is correct, a good estimate of the pi-eta
mixing angle is obtained, if the experimental cross sections for the dd --> pi
alpha reaction at the corresponding deuteron input energy are taken from the
literature.


title:
Extended Gari-Krumpelmann model fits to nucleon electromagnetic form
  factors

abstract:
  Nucleon electromagnetic form factor data (including recent data) is fitted
with models that respect the confinement and asymptotic freedom properties of
QCD. Gari-Krumpelmann (GK) type models, which include the major vector meson
pole contributions and at high momentum transfer conform to the predictions of
perturbative QCD, are combined with Hohler-Pietarinen (HP) models, which also
include the width of the rho meson and the addition of higher mass vector meson
exchanges, but do not evolve into the explicit form of PQCD at high momentum
transfer. Different parameterizations of the GK model's hadronic form factors,
the effect of including the width of the rho meson and the addition of the next
(in mass) isospin 1 vector meson are considered. The quality of fit and the
consistency of the parameters select three of the combined HP/GK type models.
Projections are made to the higher momentum transfers which are relevant to
electron-deuteron experiments. The projections vary little for the preferred
models, removing much of the ambiguity in electron-nucleus scattering
predictions.


title: Microscopic Reaction Dynamics at SPS and RHIC

abstract:
  The current status of transport theoretical models applicable to the physics
of the Relativistic Heavy-Ion Collider is reviewed. The time evolution of
microscopic reaction dynamics - from early, hard, partonic rescattering up to
soft hadronic interactions close to freeze-out is analyzed and key observables
linked to the different reaction stages are discussed.


title: Hydro+Cascade, Flow, the Equation of State, Predictions and Data

abstract:
  A Hydro+Cascade model has been used to describe radial and elliptic flow at
the SPS and successfully predicted the radial and elliptic flow measured by the
both STAR and PHENIX collaborations . Furthermore, a combined description of
the radial and elliptic flow for different particle species, restricts the
Equation of State(EoS) and points towards an EoS with a phase transition to the
Quark Gluon Plasma(QGP) .


title:
Strange hadrons and their resonances: a diagnostic tool of QGP
  freeze-out dynamics

abstract:
  We update our chemical analysis of (strange) hadrons produced at the SPS in
Pb--Pb collisions at 158A GeV and and present a first chemical analysis of RHIC
results. We report that the shape of (anti)hyperon m_T-spectra in a thermal
freeze-out analysis leads to freeze-out conditions found in chemical analysis,
implying sudden strange hyperon production. We discuss how a combined analysis
of several strange hadron resonances of differing lifespan can be used to
understand the dynamical process present during chemical and thermal
freeze-outs. In medium resonance quenching is considered.


title: A New Slant on Hadron Structure

abstract:
  Rather than regarding the restriction of current lattice QCD simulations to
quark masses that are 5--10 times larger than those observed, we note that this
presents a wonderful opportunity to deepen our understanding of QCD. Just as it
has been possible to learn a great deal about QCD by treating $N_c$ as a
variable, so the study of hadron properties as a function of quark mass is
leading us to a much deeper appreciation of hadron structure. As examples we
cite recent progress in using the chiral properties of QCD to connect hadron
masses, magnetic moments, charge radii and structure functions calculated at
large quark masses within lattice QCD with the values observed physically.


title: Signature inversion in axially deformed $^{160,162}$Tm

abstract:
  The microscopic analysis of experimental data in $^{160,162}$Tm is presented
within the two-quasiparticle-phonon model. The model includes the interaction
between odd quasiparticles and their coupling with core vibrations. The
coupling explains naturally the attenuation of the Coriolis interaction in
rotating odd-odd nuclei. It is shown that the competition between the Coriolis
and neutron-proton interactions is responsible for the signature inversion
phenomenon.


title: Remarks on Delta Radiative and Dalitz Decays

abstract:
  Phenomenological expressions are derived for rates of the $\Delta (1232)$
radiative and Dalitz decays, $\Delta (1232)$ $\to N\gamma$ and $\Delta (1232)$
$\to Ne^{+}e^{-}$. Earlier calculations of these decays are commented.


title: Higher and missing resonances in omega photoproduction

abstract:
  We study the role of the nucleon resonances ($N^*$) in $\omega$
photoproduction by using the quark model resonance parameters predicted by
Capstick and Roberts. The employed $\gamma N \to N^*$ 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 important in the differential cross sections at large scattering
angles and various spin observables. In particular, the parity asymmetry and
beam-target double asymmetry at forward scattering angles are suggested for a
crucial test of our predictions. The dominant contributions are found to be
from $N\frac32^+ (1910)$, a missing resonance, and $N\frac32^- (1960)$ which is
identified as the $D_{13}(2080)$ of the Particle Data Group.


title:
New results for two-neutrino double beta decay with large
  particle-particle two body proton-neutron interaction

abstract:
  A model many-body Hamiltonian describing an heterogenous system of paired
protons and paired neutrons and interacting among themselves through monopole
particle-hole and monopole particle-particle interactions is used to study the
double beta decay of Fermi type. The states are described by time dependent
approaches choosing as trial functions coherent states of the symmetry groups
underlying the model Hamiltonian. One formalism, VP1, is fully equivalent with
the standard pnQRPA and therefore fails at a critical value of the
particle-particle interaction strength while another one, VP2, corresponds to a
two step BCS treatment, i.e. the proton quasiparticles are paired with the
neutron quasiparticles. In this way a harmonic description for the double beta
transition amplitude is provided for any strength of the particle-particle
interaction. The approximation quality is judged by comparing the actual
results with the exact result as well as with those corresponding to various
truncations of the boson expanded Hamiltonian and transition operator. Finally
it is shown that the dynamic ground states provided by VP1 and VP2 are
reasonable well approximated by solutions of a variational principle. This
remark constitutes a step forward finding an approach where the RPA ground
state is a solution of a variational principle equation.


title: Coulomb displacement energies, energy differenced and neutron skins

abstract:
  A Fock space representation of the monopole part of the Coulomb potential is
presented. Quantum effects show through a small orbital term in $l(l+1)$. Once
it is averaged out, the classical electrostatic energy emerges as an
essentially exact expression, which makes it possible to eliminate the
Nolen-Schiffer anomaly, and to estimate neutron skins and the evolution of
radii along yrast states of mirror nuclei. The energy differences of the latter
are quantitatively reproduced by the monopole term and a schematic multipole
one.


title: Microscopic optical potentials for nucleon-nucleus scattering

abstract:
  Microscopic optical potentials for nucleon-nucleus (NA) scattering obtained
from the full folding of the effective g matrices, solutions of the
Bruckner-Bethe-Goldstone equation, with the densities of the target, are
applied to the case of neutron-nucleus scattering. Given that the optical
potentials are specified in all two-body angular momentum, spin and isospin
channels available to the NA scattering, the only difference in this model
description of proton and neutron scattering observables for a given nucleus is
in the inclusion of the Coulomb interaction. A priori microscopic optical model
predictions for neutron and proton elastic scattering are compared with results
from a phenomenological optical model and with data. New measurements are
recommended to reduce discrepancies in the existing database, and to
differentiate between different theoretical predictions.


title: The Local Potential Approximation for the Brueckner G-matrix

abstract:
  The Brueckner G-matrix for a slab of nuclear matter is analyzed in the
singlet $^1S$ and triplet $^3S+^3D$ channels. The complete Hilbert space is
split into two domains, the model subspace $S_0$, in which the two-particle
propagator is calculated explicitly, and the complementary one, $S'$, in which
the local potential approximation is used. This kind of local approximation was
previously found to be quite accurate for the $^1S$ pairing problem. A set of
model spaces $S_0(E_0)$ with different values of the cut-off energy $E_0$ is
considered, $E_0$ being the upper limit for the single-particle energies of the
states belonging to $S_0$. The independence of the G-matrix of $E_0$ is assumed
as a criterion of validity of the local potential approximation. Such
independence is obtained within few percent for $E_0=10 \div 20$ MeV for both
the channels under consideration.


title:
Deformations of the fermion realization of the sp(4) algebra and its
  subalgebras

abstract:
  With a view towards future applications in nuclear physics, the fermion
realization of the compact symplectic sp(4) algebra and its q-deformed versions
are investigated. Three important reduction chains of the sp(4) algebra are
explored in both the classical and deformed cases. The deformed realizations
are based on distinct deformations of the fermion creation and annihilation
operators. For the primary reduction, the su(2) sub-structure can be
interpreted as either the spin, isospin or angular momentum algebra, whereas
for the other two reductions su(2) can be associated with pairing between
fermions of the same type or pairing between two distinct fermion types. Each
reduction provides for a complete classification of the basis states. The
deformed induced u(2) representations are reducible in the action spaces of
sp(4) and are decomposed into irreducible representations.

categories: nucl-th math-ph math.GR math.MP math.QA math.RT


title: Coupled-channel study of gamma p --> K+ Lambda

abstract:
  A coupled-channel (CC) approach has been developed to investigate kaon
photoproduction on the nucleon. In addition to direct K+ Lambda production, our
CC approach accounts for strangeness production including K+ Lambda final state
interactions with both pi0 p and pi+ n intermediate states. Calculations for
the gamma p --> K+ Lambda reaction have been performed, and compared with the
recent data from SAPHIR, with emphasis on the CC effects. We show that the CC
effects are significant at the level of inducing 20% changes on total cross
sections; thereby, demonstrating the need to include pi N channels to correctly
describe the gamma p --> K+ Lambda reaction.


title: Final state interactions in the eta-d system

abstract:
  The eta-deuteron scattering amplitude is calculated with a recent K-matrix
model of eta-N interactions. The existence of a narrow virtual state in the
eta-deuteron system is inferred. This state couples strongly to the eta-d
channel but its effect on final state interactions in the pn --> eta-d reaction
is shown to be rather weak. Fairly large eta-N scattering lengths are allowed
by the experimental data.


title:
Elliptic flow at collider energies and cascade string models: The role
  of hard processes and multi-Pomeron exchanges

abstract:
  Centrality, rapidity, and transverse momentum dependence of hadron elliptic
flow is studied in Au+Au collisions at BNL RHIC energies within the microscopic
quark-gluon string model. The QGSM predictions coincide well with the
experimental data at $\sqrt{s}=130$ AGeV. Further investigations reveal that
multi-Pomeron exchanges and hard gluon-gluon scattering in primary collisions,
accompanied by the rescattering of hadrons in spatially anisotropic system, are
the key processes needed for an adequate description of the data. These
processes become essentially important for heavy-ion collisions at full RHIC
energy $\sqrt{s}=200$ AGeV.


title: Two-Frequency Shell-Model Calculations for p-Shell Nuclei

abstract:
  We have studied p-shell nuclei using a two-frequency shell-model approach
with an effective interaction derived from the Bonn-A nucleon-nucleon potential
by means of a G-matrix folded-diagram method. Shell-model wave functions of two
different oscillator constant are employed, one for the inner 0s core orbit and
the outer valence orbits, respectively. The binding energies, energy spectra,
and electromagnetic properties are calculated and compared with experiment. A
quite satisfactory agreement with the experimental data is obtained, which is
in some cases even better than that produced by large-basis shell-model
calculations.


title:
Scaling of hadronic transverse momenta in a hydrodynamic treatment of
  relativistic heavy ion collisions

abstract:
  The transverse momenta of hadrons in central nucleus-nucleus collisions are
evaluated in a boost invariant hydrodynamics with transverse expansion. Quark
gluon plasma is assumed to be formed in the initial state which expands and
cools via a first order phase transition to a rich hadronic matter and
ultimately undergoes a freeze-out. The average transverse momentum of pions,
kaons, and protons is estimated for a wide range of multiplicity densities and
transverse sizes of the system. For a given system it is found to scale with
the square-root of the particle rapidity density per unit transverse area, and
consistent with the corresponding values seen in $p\overline{p}$ experiments at
1800 GeV, suggesting a universal behaviour. The average transverse momentum
shows only an approximate scaling with multiplicity density per nucleon which
is at variance with the $p\overline{p}$ data.


title: Benchmark Test Calculation of a Four-Nucleon Bound State

abstract:
  In the past, several efficient methods have been developed to solve the
Schroedinger equation for four-nucleon bound states accurately. These are the
Faddeev-Yakubovsky, the coupled-rearrangement-channel Gaussian-basis
variational, the stochastic variational, the hyperspherical variational, the
Green's function Monte Carlo, the no-core shell model and the effective
interaction hyperspherical harmonic methods. In this article we compare the
energy eigenvalue results and some wave function properties using the realistic
AV8' NN interaction. The results of all schemes agree very well showing the
high accuracy of our present ability to calculate the four-nucleon bound state.


title: Collective Dipole Bremsstrahlung in Fusion Reactions

abstract:
  We estimate the dipole radiation emitted in fusion processes. We show that a
classical bremsstrahlung approach can account for both the preequilibrium and
the thermal photon emission. We give an absolute evaluation of the
pre-equilibrium component due to the charge asymmetry in the entrance channel
and we study the energy and mass dependence in order to optimize the
observation. This dynamical dipole radiation could be a relevant cooling
mechanism in the fusion path. We stress the interest in experiments with the
new available radioactive beams.


title: One and Two-photon Physics with Relativistic Heavy Ions

abstract:
  The physics of peripheral collisions with relativistic heavy ions (PCRHI) is
reviewed. One- and two-photon processes are discussed.


title:
Dipole resonances in oxygen isotopes in time-dependent density-matrix
  theory

abstract:
  The strength functions of isovector dipole resonances in the even oxygen
isotopes $^{18\sim24}$O are calculated by using an extended version of the
time-dependent Hartree-Fock theory known as the time-dependent density-matrix
theory (TDDM). The results are compared with recent experimental data and also
with a shell-model calculation. It is found that the observed isotope
dependence of low-lying dipole strength is reproduced in TDDM when the strength
of the residual interaction is properly chosen. It is also found that there is
a difference between the TDDM prediction and the shell-model calculation for
$^{24}$O.


title:
Microscopic Calculation of Total Ordinary Muon Capture Rates for Medium
  - Weight and Heavy Nuclei

abstract:
  Total Ordinary Muon Capture (OMC) rates are calculated on the basis of the
Quasiparticle Random Phase Approximation for several spherical nuclei from
90^Zr to 208^Pb. It is shown that total OMC rates calculated with the free
value of the axial-vector coupling constant g_A agree well with the
experimental data for medium-size nuclei and exceed considerably the
experimental rates for heavy nuclei. The sensitivity of theoretical OMC rates
to the nuclear residual interactions is discussed.


title:
Dynamical description of the breakup of one-neutron halo nuclei 11Be and
  19C

abstract:
  We investigate the breakup of the one-neutron halo nuclei 11Be and 19C within
a dynamical model of the continuum excitation of the projectile. The time
evolution of the projectile in coordinate space is described by solving the
three-dimensional time dependent Schroedinger equation, treating the
projectile-target (both Coulomb and nuclear) interaction as a time dependent
external perturbation. The pure Coulomb breakup dominates the relative energy
spectra of the fragments in the peak region, while the nuclear breakup is
important at higher relative energies. The coherent sum of the two
contributions provides a good overall description of the experimental spectra.
Cross sections of the first order perturbation theory are derived as a limit of
our dynamical model. The dynamical effects are found to be of the order of
10-15% for the beam energies in the range of 60 - 80 MeV/nucleon. A comparison
of our results with those of a post form distorted wave Born approximation
shows that the magnitudes of the higher order effects are dependent on the
theoretical model.


title: Low Energy Proton-Deuteron Scattering in Configuration Space

abstract:
  A new method for solving the configuration-space Faddeev equations for
elastic p-d scattering below the deuteron-breakup threshold is described.
Numerical solutions that demonstrate the convergence and accuracy of the method
are given. The number of channels and the value of the matching radius required
to obtain an accurate solution are also investigated. These calculations
demonstrate that this method can efficiently solve the large matrix equations
required for the three-body scattering problem.


title:
Second Order Dissipative Fluid Dynamics for Ultra-Relativistic Nuclear
  Collisions

abstract:
  The M\"uller-Israel-Stewart second order theory of relativistic imperfect
fluids based on Grad's moment method is used to study the expansion of hot
matter produced in ultra-relativistic heavy ion collisions. The temperature
evolution is investigated in the framework of the Bjorken boost-invariant
scaling limit. The results of these second-order theories are compared to those
of first-order theories due to Eckart and to Landau and Lifshitz and those of
zeroth order (perfect fluid) due to Euler.


title:
Relativistic Hartree-Bogoliubov Approach for Nuclear Matter with
  Non-Linear Coupling Terms

abstract:
  We investigate the pairing property of nuclear matter with Relativistic
Hartree-Bogoliubov(RHB) approach. Recently, the RHB approach has been widely
applied to nuclear matter and finite nuclei. We have extended the RHB approach
to be able to include non-linear coupling terms of mesons. In this paper we
apply it to nuclear matter and observe the effect of non-linear terms on
pairing gaps.


title: Jet Quenching and the p-bar >= pi- Anomaly at RHIC

abstract:
  PHENIX data on Au+Au at root(s)_= 130 AGeV suggest that p-bar yields may
exceed pi- at high p_T > 2 GeV/c. We propose that jet quenching in central
collisions suppresses the hard PQCD component of the spectra in central A+A
reactions, thereby exposing a novel component of baryon dynamics that we
attribute to (gluonic) baryon junctions. We predict that the observed p-bar >=
pi- and the p > pi+ anomaly at p_T ~ 2 GeV/c is limited to a finite p_T window
that decreases with increasing impact parameter.


title:
Determination of pi-N scattering lengths from pionic hydrogen and pionic
  deuterium data

abstract:
  The pi-N s-wave scattering lengths have been inferred from a joint analysis
of the pionic hydrogen and the pionic deuterium x-ray data using a
non-relativistic approach in which the pi-N interaction is simulated by a
short-ranged potential. The pi-d scattering length has been calculated exactly
by solving the Faddeev equations and also by using a static approximation. It
has been shown that the same very accurate static formula for pi-d scattering
length can be derived (i) from a set of boundary conditions; (ii) by a
reduction of Faddeev equations; and (iii) through a summation of Feynman
diagrams. By imposing the requirement that the pi-d scattering length,
resulting from Faddeev-type calculation, be in agreement with pionic deuterium
data, we obtain bounds on the pi-N scattering lengths. The dominant source of
uncertainty on the deduced values of the pi-N scattering lengths are the
experimental errors in the pionic hydrogen data.


title: Asymmetries in phi photoproduction and the OZI violation

abstract:
  We study the vector meson density matrix and the associated polarization
asymmetries in $\phi$ photoproduction near threshold. In order to study the OZI
violating processes, we consider the direct $\phi NN$ coupling as well as the
knockout processes arising from the non-vanishing $s\bar{s}$ sea quarks in the
nucleon. The polarization asymmetries in $\phi$ meson decays are found to be
very useful to constrain the $\phi NN$ coupling constant. The hidden
strangeness of the nucleon can also be studied by these asymmetries, but mostly
at large $|t|$ region.


title:
Spectroscopy of one-neutron halo nuclei from the Coulomb breakup
  reactions

abstract:
  We review the current status of obtaining the spectroscopic information on
the one-neutron halo nuclei from the Coulomb breakup reactions. The theory of
these reactions formulated in the framework of the Distorted Wave Born
Approximation, allows the use of the realistic wave functions corresponding to
any orbital angular momentum structure for the core-valence neutron relative
motion in the ground state of the projectile. The energy, angular and parallel
momentum distributions of the projectile fragments calculated within this
theory are selective about the ground state wave function of the projectile.
Therefore, firm conclusions can be drawn about the structure of the projectile
ground state by comparing the calculations with the corresponding data.


title: Status of Nucleon Resonances with Masses $M<M_N+M_{\pi}$

abstract:
  We discuss different interpretations of peaks observed a few years ago by
Tatischeff et al. in missing mass spectra of the reaction $pp->pi^+pX$, which
were declared as new exited nucleon states with small masses. A study of the
possible production of such states in the process $\gamma p->pi^+N^*->pi^+
+\gamma\gamma n$ by analyzing the invariant mass spectrum of $\gamma\gamma n$
is proposed. It is shown that the data, obtained recently at MAMI-B, can allow
to analyze this process and to get information about an existence of exited
nucleon states with small masses.


title: Remarks on the extraction of freeze-out parameters

abstract:
  I review the extraction of kinetic and chemical freeze-out parameters from
experimental data, with particular emphasis on the underlying assumptions and
the validity of the conclusions.


title: Study of $\Lambda$ hypernuclei in the quark mean field model

abstract:
  We extend the quark mean field model to the study of $\Lambda$ hypernuclei.
Without adjusting parameters, the properties of $\Lambda$ hypernuclei can be
described reasonably well. The small spin-orbit splittings for $\Lambda$ in
hypernuclei are achieved, while the $\Lambda$ single particle energies in the
present model are slightly underestimated as compared with the experimental
values. About 3% deviation from the quark model prediction for the
$\omega-\Lambda$ couplings is required in order to reproduce the experimental
single particle energies.


title:
Saturation of Elliptic Flow and the Transport Opacity of the Gluon
  Plasma at RHIC

abstract:
  Differential elliptic flow and particle spectra are calculated taking into
account the finite transport opacity of the gluon plasma produced in Au+Au at
Ecm ~ 130 A GeV at RHIC. Covariant numerical solutions of the ultrarelativistic
Boltzmann equation are obtained using the MPC parton cascade technique. For
typical pQCD (~3 mb) elastic cross sections, extreme initial gluon densities,
dN/deta ~ 15000, are required to reproduce the elliptic flow saturation pattern
reported by STAR. However, we show that the solutions depend mainly on the
transport opacity, $\chi=\int dz \sigma_t\rho_g$, and thus the data can also be
reproduced with dN/deta ~ 1000, but with extreme elastic parton cross sections,
\~45 mb. We demonstrate that the spectra and elliptic flow are dominated by
numerical artifacts unless parton subdivisions ~100-1000 are applied to retain
Lorentz covariance for RHIC initial conditions.


title: Spectator Response to the Participant Blast

abstract:
  The interplay between spectator and participant matter in heavy-ion
collisions is investigated in the context of a microscopic transport model.
Transport simulations show that flow patterns for the participant matter are
strongly influenced by the presence of the nearby spectator matter. However,
the influence is mutual. During the explosion of the participant zone, the
spectator matter acquires a transverse momentum $<P^x /A>$ that shows
sensitivity to the nuclear incompressibility and to the momentum dependence of
the nuclear mean field (MF). An observed change in the net average momentum per
nucleon, $\Delta |< {\bf P}/A >|$, can be associated with the momentum
dependence of the MF. For a momentum-dependent MF and a low impact parameter in
a heavy system, the spectators may emerge faster than in the initial state,
accelerated by the violent participant explosion. The average excitation energy
and the mass of the spectators, in contrast to the momentum, show little
sensitivity to the nuclear equation of state.


title: Temperature induced shell effects in deformed nuclei

abstract:
  The thermal evolution of the shell correction energy is investigated for
deformed nuclei using Strutinsky prescription in a self-consistent relativistic
mean-field framework. For temperature independent single-particle states
corresponding to either spherical or deformed nuclear shapes, the shell
correction energy $\Delta_{sc}$ steadily washes out with temperature. However,
for states pertaining to the self-consistent thermally evolving shapes of
deformed nuclei, the dual role played by the single-particle occupancies in
diluting the fluctuation effects from the single-particle spectra and in
driving the system towards a smaller deformation is crucial in determining
$\Delta_{sc}$ at moderate temperatures. In rare earth nuclei, it is found that
$\Delta_{sc}$ builds up strongly around the shape transition temperature; for
lighter deformed nuclei like $^{64}Zn$ and $^{66}Zn$, this is relatively less
prominent.


title: Quasideuteron states with deformed core

abstract:
  The M1 transitions between low-lying T=1 and T=0 states in deformed odd-odd
N=Z nuclei are analyzed in the frames of the rotor-plus-particle model. Using
the representation of an explicit coupling of angular momenta we show that
strong coupling of the quasideuteron configurations to the axially deformed
core results in a distribution of the total 0+ --> 1+ strength among a few
low-lying 1+ states. Simple analytical formulae for B(M1) values are derived.
The realization of the M1 sum rule for the low-lying 1+,T=0 states is
indicated. The calculated B(M1) values are found to be in good agreement with
experimental data and reveal specific features of collectivity in odd-odd N=Z
nuclei.


title: Polarized photons in radiative muon capture

abstract:
  We discuss the measurement of polarized photons arising from radiative muon
capture. The spectrum of left circularly polarized photons or equivalently the
circular polarization of the photons emitted in radiative muon capture on
hydrogen is quite sensitive to the strength of the induced pseudoscalar
coupling constant $g_P$. A measurement of either of these quantities, although
very difficult, might be sufficient to resolve the present puzzle resulting
from the disagreement between the theoretical prediction for $g_P$ and the
results of a recent experiment. This sensitivity results from the absence of
left-handed radiation from the muon line and from the fact that the leading
parts of the radiation from the hadronic lines, as determined from the chiral
power counting rules of heavy-baryon chiral perturbation theory, all contain
pion poles.


title:
Transverse Momentum Dependence of Anomalous J/\psi Suppression in Pb-Pb
  Collisions

abstract:
  The recently published data for $<p^2_t>$ for $J/\psi$ production in Pb-Pb
collisions at 158 A GeV are analyzed. For low values of transverse energy
$E_t$, where normal suppression dominates, $<p^2_t> (E_t)$ scales with the path
length of the gluons which fuse to make the $J/\psi$. In the $E_t$ domain of
anomalous suppression $<p^2_t> (E_t)$ is found to rise linearly with the
relative amount of anomalous suppression. This empirical law is reproduced
within an analytically solvable transport model which allows high $p_t$
$J/\psi$'s to escape anomalous suppression. Interpreted in this way, the data
for $<p^2_t> (E_t)$ lead to an estimate of $t_A \sim 4$ fm/$c$ for the duration
of anomalous suppression.


title: Quantum tunneling and the principle of relativity

abstract:
  It is shown that the results of Buttiker and Landauer on the traversal time
of quantum tunneling through a potential barrier are in agreement with the
principle of relativity. Also, they are consistent with the data on the
life-time of nuclear particles that decay in flight. PACS number: 03.30,
Special Relativity


title: Final State Interactions in Hypernuclear Decay

abstract:
  We present an update of the One-Meson-Exchange (OME) results for the weak
decay of s- and p-shell hypernuclei (Ref. Phys. Rev. C {\bf 56}, 339 (1997)),
paying special attention to the role played by final state interactions between
the emitted nucleons. The present study also corrects for a mistake in the
inclusion of the $K$ and $K^*$ exchange mechanisms, which substantially
increases the ratio of neutron-induced to proton-induced transitions,
$\Gamma_n/\Gamma_p$. With the most up-to-date model ingredients, we find that
the OME approach is able to describe very satisfactorily most of the measured
observables, including the ratio $\Gamma_n/\Gamma_p$.


title:
The production of eta-mesons in nucleon-nucleon collisions near
  threshold

abstract:
  Data on the total cross sections for the pp -> pp eta, pn -> pn eta, and pn
-> d eta reactions and the pp -> pp eta differential cross section near
threshold are analysed in a one-meson-exchange model. After including initial
and final-state nucleon-nucleon distortion, the magnitude and most of the
energy dependence are well reproduced. It is found that the contribution of
rho-exchange is larger than that of pi-exchange. With destructive rho/pi
interference in the pp case, the model explains quantitatively the pp -> pp
eta/pn -> pn eta cross section ratio and the slope of the pp -> pp eta
differential cross section. Such an agreement would be destroyed by any
significant eta-exchange term. The residual energy dependence may be associated
with eta-nucleon rescattering that has not been taken into account. The pn ->
pn eta/pn -> d eta ratio depends weakly upon the nature of the particle
exchanges, being determined primarily by the nucleon-nucleon final state
interactions. The proton analysing power is predicted to remain small in the
low energy region.


title: Ground state particle-particle correlations and double beta decay

abstract:
  A self-consistent formalism for the double beta decay of Fermi type is
provided. The particle-particle channel of the two-body interaction is
considered first in the mean field equations and then in the QRPA. The
resulting approach is called the QRPA with a self-consistent mean field
(QRPASMF). The mode provided by QRPASMF, does not collapse for any strength of
the particle-particle interaction. The transition amplitude for double beta
decay is almost insensitive to the variation of the particle-particle
interaction. Comparing it with the result of the standard pnQRPA, it is smaller
by a factor 6. The prediction for transition amplitude agrees quite well with
the exact result. The present approach is the only one which produces a strong
decrease of the amplitude and at the same time does not alter the stability of
the ground state.


title: Electroweak Probes and Nuclear Effective Field Theory

abstract:
  There is growing interest in nuclear physics applications of effective field
theory. I give a brief account of some of the latest developments in this area.
I also describe interplay between this new approach and the traditional nuclear
physics approach.


title:
Quark Model Study of The eta Photoproduction: Evidence for a New S11
  Resonance?

abstract:
  An extensive and systematic study of the recent eta photoproduction data up
to 1.2 GeV is presented within a chiral constituent quark model. A model
embodying all known nucleonic resonances shows clear need for a yet
undiscovered third S11 resonance in the second resonance region, for which we
determine the mass (1.729 GeV) and the total width (183 MeV). Furthermore, we
extract the configuration mixing angles, an important property of the
quark-quark interaction in the quark model, for the resonances S11(1535) and
S11(1650), as well as for the resonances D13(1520) and D13(1700). Our results
agree well with the quark model predictions. In addition, the partial eta N
decay widths and/or the photo-excitation helicity amplitudes for the nucleonic
resonances S11(1535), S11(1650), P11(1710), P13(1720), D13(1520), D13(1700),
D15(1675), and F15(1680) are also obtained in this approach.


title:
An exact stochastic mean-field approach to the fermionic many-body
  problem

abstract:
  We investigate a reformulation of the dynamics of interacting fermion systems
in terms of a stochastic extension of Time Dependent Hartree-Fock equations.
The noise is found from a path-integral representation of the evolution
operator and allows to interpret the exact N-body state as a coherent average
over Slater determinants evolving under the random mean-fied. The full density
operator and the expectation value of any observable are then reconstructed
using pairs of stochastic uncorrelated wave functions. The imaginary time
propagation is also presented and gives a similar stochastic one-body scheme
which converges to the exact ground state without developing a sign problem. In
addition, the growth of statistical errors is examined to show that the
stochastic formulation never explode in a finite dimensional one-body space.
Finally, we consider initially correlated systems and present some numerical
implementations in exactly soluble models to analyse the precision and the
stability of the approach in practical cases.


title: Mesons electromagnetic production study via a constituent quark approach

abstract:
  Using a chiral constituent quark approach based on the broken SU(6) \otimes
O(3) symmetry, we focus on the spectroscopy of isospin-1/2 nucleonic
resonances. A model for the eta photoproduction, embodying all known nucleonic
resonances, shows clear need for a yet undiscovered S11 resonance, for which we
determine the mass (1.730 GeV) and the total width (180 MeV).


title: Study of chirally motivated low-energy $K^-$ optical potentials

abstract:
  The $K^-$ optical potential in the nuclear medium is evaluated self
consistently from a free-space $K^-N$ $t$ matrix constructed within a
coupled-channel chiral approach to the low-energy $\bar K N$ data. The
chiral-model parameters are fitted to a select subset of the low-energy data
{\it plus} the $K^-$ atomic data throughout the periodic table. The resulting
attractive $K^-$ optical potentials are relatively `shallow', with central
depth of the real part about 55 MeV, for a fairly reasonable reproduction of
the atomic data with $\chi^2 / N \approx 2.2$. Relatively `deep' attractive
potentials of depth about 180 MeV, which result in other phenomenological
approaches with $\chi^2 / N \approx 1.5$, are ruled out within chirally
motivated models. Different physical data input is required to distinguish
between shallow and deep $K^-$ optical potentials. The ($K^{-}_{\rm stop},\pi$)
reaction could provide such a test, with exclusive rates differing by over a
factor of three for the two classes of potentials. Finally, forward ($K^-,p$)
differential cross sections for the production of relatively narrow deeply
bound $K^-$ {\it nuclear} states are evaluated for deep $K^-$ optical
potentials, yielding values considerably lower than those estimated before.


title: Effective Range in Doublet S-wave Neutron-Deuteron Scattering

abstract:
  The effective field theory approach is applied to the three-nucleon process
of $S=1/2$ neutron-deuteron scattering in the S-wave, including the effective
range parameters summed at all orders. This is achieved through a modification
of the power counting, following a recent suggestion in the literature. It is
shown that with this procedure, while the convergence of the loop integrals
improves, one cannot meaningfully include a three-body effective term to
describe low-energy data affected by the presence of the triton bound state.


title: Hydrodynamic flow at RHIC

abstract:
  We review the apparently hydrodynamic behaviour of low transverse momentum
particles (p_T < 1.5 GeV/c) produced in central and semicentral (b < 7 fm)
heavy ion collisions at RHIC. We investigate the impact parameter dependence of
various observables, elaborating on radial and elliptic flow and particle
multiplicities. We also discuss possible ambiguities in the initialization of
the hydrodynamic system and present observables that should allow for their
resolution.


title: Critical Exponents of the Statistical Multifragmentation Model

abstract:
  For the statistical multifragmentation model the critical indices
$\alpha^\prime, \beta, \gamma^\prime, \delta$ are calculated as functions of
the Fisher parameter $\tau$. It is found that these indices have different
values than in Fisher's droplet model. Some peculiarities of the scaling
relations are discussed. The basic model predicts for the index $\tau$ a narrow
range of values, $1.799< \tau < 1.846$, which is consistent with two
experiments on nuclear multifragmentation.


title: From known to undiscovered resonances

abstract:
  Electromagnetic meson production formalisms are reviewed, with emphasise
placed on their ability in search for new baryon resonances via gamma p -> K+
Lambda and gamma p -> eta p processes. The relevant studies, aiming to deepen
our insights to hadron spectroscopy, constitute strong tests of the QCD
inspired theoretical developements.


title:
Radiative corrections to polarization observables for elastic
  $e+A$-scattering. Part I: Virtual Compton Scattering

abstract:
  We calculate polarization phenomena for virtual Compton scattering on
protons, at relatively large momentum transfer 1 GeV$^2$ $\le -q^2\le$ 5
GeV$^2$ on the basis of a model for $\gamma^*+ p\to \gamma+p$ with two main
contributions: $\pi^0$-exchange in $t-$channel and $\Delta$-excitation in
$s$-channel. This model applies from threshold to $\Delta$ region. The
parameters entering in this model, such as coupling constants and
electromagnetic form factors are well known. The analyzing powers for
$\gamma^*+\vec p\to \gamma+ p$ and the components of the final proton
polarization in $\gamma^*+ p\to \gamma+ \vec p$ are large in absolute value and
show strong sensitivity to $\pi\bigotimes\Delta$ interference. These results
can be applied to the calculation of radiative corrections to polarization
phenomena in elastic $ep$-scattering.


title: Particle number projection with effective forces

abstract:
  The particle number projection method is formulated for density dependent
forces and in particular for the finite range Gogny force. Detailed formula for
the projected energy and its gradient are provided. The problems arising from
the neglection of any exchange term, which may lead to divergences, are
throughly discussed and the possible inaccuracies estimated. Numericala results
for the projection after variation method are shown for the nucleus 164Er and
for the projection before variation approach for the nuclei 48-50Cr. We also
confirm the Coulomb antipairing effect found in mean field theories.


title: Detailed analysis of eta production in proton-proton collisions

abstract:
  The check whether the presently available multiresonance coupled channel
analyses can explain the more complex processes is made. The process chosen is
a well measured proces of eta production in proton proton collisions.


title:
Properties of Dense Strange Hadronic Matter with Quark Degrees of
  Freedom

abstract:
  The properties of strange hadronic matter are studied in the context of the
modified quark-meson coupling model using two substantially different sets of
hyperon-hyperon ($YY$) interactions. The first set is based on the Nijmegen
hard core potential model D with slightly attractive $YY$ interactions. The
second potential set is based on the recent SU(3) extension of the Nijmegen
soft-core potential NSC97 with strongly attractive $YY$ interactions which may
allow for deeply bound hypernuclear matter. The results show that, for the
first potential set, the $\Sigma$ hyperon does not appear at all in the bulk at
any baryon density and for all strangeness fractions. The binding energy curves
of the resulting $N\Lambda\Xi$ system vary smoothly with density and the system
is stable (or metastable if we include the weak force). However, the situation
is drastically changed when using the second set where the $\Sigma$ hyperons
appear in the system at large baryon densities above a critical strangeness
fraction. We find strange hadronic matter undergoes a first order phase
transition from a $N\Lambda\Xi$ system to a $N\Sigma\Xi$ for strangeness
fractions $f_S>1.2$ and baryonic densities exceeding twice ordinary nuclear
matter density. Furthermore, it is found that the system built of $N\Sigma\Xi$
is deeply bound. This phase transition affects significantly the equation of
state which becomes much softer and a substantial drop in energy density and
pressure are detected as the phase transition takes place.


title:
The pairing Hamiltonian for one pair of identical nucleons bound in a
  potential well

abstract:
  The problem of one pair of identical nucleons sitting in ${\cal N}$ single
particle levels of a potential well and interacting through the pairing force
is treated introducing even Grassmann variables. The eigenvectors are
analytically expressed solely in terms of these with coefficients fixed by the
eigenvalues and the single particle energies. When the latter are those of an
harmonic oscillator well an accurate expression is derived for both the
collective eigenvalue and for those trapped in between the single particle
levels, for any strength of the pairing interaction and for any number of
levels. Notably the trapped solutions are labelled through an index upon which
they depend parabolically.


title:
Polarization Phenomena in Hadronic and Nuclear Processes in Threshold
  Regime

abstract:
  The threshold region for processes of hadronic and nuclear interactions is
very interesting for a theoretical as well as an experimental point of view. In
this region one can apply different physical methods, starting from classical
current algebra methods - for processes invloving soft pions, through effective
Lagrangian approaches - or perturbative chiral symmetry theory (ChPT). The
essential simplification of the spin structure of matrix elements for threshold
regime results in better understanding of the underlying mechanisms and allows
the analysis of polarization phenomena. A dedicated formalism is developed here
for a wide class of processes including even such complicated processes as
production of pseudoscalar and vector mesons in nucleon-nucleon collisions.
Many interesting physical problems are discussed: hidden strangeness of
nucleons and OZI-violation, $\eta N$ -and $\omega N$ interactions in S-state,
the determination of P-parity of strange particles. Special attention is
devoted to the analysis of the spin structure and polarization phenomena for
nuclear processes with light nuclei which have important applications in
fundamental astrophysics and in nuclear fusion.


title: The role of hyperon resonances in p(gamma,K+)Lambda processes

abstract:
  We discuss the role of hyperon resonances in the u-channel when modeling p
(gamma,K+)Lambda processes in an effective Lagrangian approach. Without the
introduction of hyperon resonances, one is forced to use soft hadronic form
factors with a cutoff mass which is at best two times the kaon mass. After
inclusion of the hyperon resonances in the u-channel, we obtain a fair
description of the data with a cutoff mass of the order of 1.8 GeV.


title:
The general harmonic-oscillator brackets: compact expression,
  symmetries, sums and Fortran code

abstract:
  We present a very simple expression and a Fortran code for the fast and
precise calculation of three-dimensional harmonic-oscillator transformation
brackets. The complete system of symmetries for the brackets along with
analytical expressions for sums, containing products of two and three brackets,
is given.


title:
Prescission neutron multiplicity and fission probability from Langevin
  dynamics of nuclear fission

abstract:
  A theoretical model of one-body nuclear friction which was developed earlier,
namely the chaos-weighted wall formula, is applied to a dynamical description
of compound nuclear decay in the framework of the Langevin equation coupled
with statistical evaporation of light particles and photons. We have used both
the usual wall formula friction and its chaos-weighted version in the Langevin
equation to calculate the fission probability and prescission neutron
multiplicity for the compound nuclei $^{178}$W, $^{188}$Pt, $^{200}$Pb,
$^{213}$Fr, $^{224}$Th, and $^{251}$Es. We have also obtained the contributions
of the presaddle and postsaddle neutrons to the total prescission multiplicity.
A detailed analysis of our results leads us to conclude that the chaos-weighted
wall formula friction can adequately describe the fission dynamics in the
presaddle region. This friction, however, turns out to be too weak to describe
the postsaddle dynamics properly. This points to the need for a suitable
explanation for the enhanced neutron emission in the postsaddle stage of
nuclear fission.


title: Nucleon-Nucleon Optical Model for Energies to 3 GeV

abstract:
  Several nucleon-nucleon potentials, Paris, Nijmegen, Argonne, and those
derived by quantum inversion, which describe the NN interaction for T-lab below
300$ MeV are extended in their range of application as NN optical models.
Extensions are made in r-space using complex separable potentials definable
with a wide range of form factor options including those of boundary condition
models. We use the latest phase shift analyses SP00 (FA00, WI00) of Arndt et
al. from 300 MeV to 3 GeV to determine these extensions. The imaginary parts of
the optical model interactions account for loss of flux into direct or resonant
production processes. The optical potential approach is of particular value as
it permits one to visualize fusion, and subsequent fission, of nucleons when
T-lab above 2 GeV. We do so by calculating the scattering wave functions to
specify the energy and radial dependences of flux losses and of probability
distributions. Furthermore, half-off the energy shell t-matrices are presented
as they are readily deduced with this approach. Such t-matrices are required
for studies of few- and many-body nuclear reactions.


title: Significance Of Deuteron Breakup In A Halo Transfer Reaction

abstract:
  We discuss the quasi-adiabatic approximations to the three-body wavefunction
in breakup processes, clarifying the assumptions underlying the model. This
suggests alternative approximation schemes. Using different theoretical
three-body models, calculated differential cross section angular distributions
for the Be-11(p,d) reaction,for which new preliminary data have been reported
at 35 MeV, are presented. We show that calculations are sensitive to the
inclusion of deuteron breakup and to the breakup model used, particularly if
used to deduce absolute spectroscopic information on the 0{+} and 2{+} Be-10
core state parentages. There is also considerable sensitivity to the model used
in calculations of the relative cross sections to the two states.


title: Halo Structure Of C-19 Via The (p,d) Reaction

abstract:
  We have investigated the heaviest one-neutron halo candidate C-19 nucleus.
Few-body model calculations of cross section angular distributions for the
C-19(p,d)C-18 reaction, together with the test calculations carried out for the
C-17(p,d)C-16 reaction, at a low incident energy are presented for different
possible halo-neutron configurations. We show that there is a clear distinction
between in particular $\ell_{n}=0$ and $\ell_{n}=2$ halo transfers. The
sensitivity of the cross sections to the assumed C-19 single neutron separation
energy is discussed.


title: New Magicity of Light Nuclei

abstract:
  A new mass formula capable of explaining the binding energies of almost all
the known isotopes from Li to Bi is prescribed. In addition to identifying the
new magic number at neutron number N=16 (Z=7-9), pseudo-magic numbers at N=14
(Z=7-10), Z=14 (N=13-19), and at N=6 (Z=3-8), the formula accounts for the loss
of magicity for nuclei with N=8 (Z=4) and N=20 (Z=12-17). The redefinition of
the neutron drip line resulting from this formula further allows us to predict
the existence of 26O,31F, 32Ne, 35Na, 38Mg, 41Al as bound nuclei and 28O as
unbound.


title:
On the relation between the Deuteron Form Factor at High Momentum
  Transfer and the High Energy Neutron-Proton Scattering Amplitude

abstract:
  A non-relativistic potential-model version of the factorization assumption,
used in perturbative QCD calculations of hadronic form factors, is used, along
with the Born approximation valid at high energies, to derive a remarkably
simple relationship between the impulse approximation contribution to the
deuteron form factor at high momentum transfer and the high energy
neutron-proton scattering amplitude. The relation states that the form factor
at a given value of $Q^2$ is proportional to the scattering amplitude at a
specific energy and scattering angle. This suggests that an accurate
computation of the form factors at large $Q^2$ requires a simultaneous
description of the phase-shifts at a related energy, a statement that seems
reasonable regardless of any derivation. Our form factor-scattering amplitude
relation is shown to be accurate for some examples. However, if the potential
consists of a strong short distance repulsive term and a strong longer ranged
attractive term, as typically occurs in many realistic potentials, the relation
is found to be accurate only for ridiculously large values of $Q$. More general
arguments, using only the Schroedinger equation, suggest a strong, but
complicated, relationship between the form factor and scattering amplitude.
Furthermore, the use of recently obtained soft potentials, along with an
appropriate current operator, may allow calculations of form factors that are
consistent with the necessary phase shifts.


title:
An Analysis of the $^{12}$C+$^{12}$C Reaction Using a New Type of
  Coupling Potential

abstract:
  A new approach has been used to explain the experimental data for the
$^{12}$C+$^{12}$C system over a wide energy range in the laboratory system from
32.0 MeV to 126.7 MeV. This new coupled-channels based approach involves
replacing the usual first derivative coupling potential by a new,
second-derivative coupling potential. This paper first shows and discusses the
limitation of the standard coupled-channels theory in the case where one of the
nuclei in the reaction is strongly deformed. Then, this new approach is shown
to improve consistently the agreement with the experimental data: the elastic
scattering, single-2$^{+}$ and mutual-2$^{+}$ excitation inelastic scattering
data as well as their 90$^{\circ}$ elastic and inelastic excitation functions
with little energy-dependent potentials. This new approach makes major
improvement on all the previous coupled-channels calculations for this system.


title:
High-spin terminating bands formed from successive particle-hole
  excitations across closed shells

abstract:
  High spin states in Zn and Dy isotopes with two protons outside the closed
shells at Z=28 and Z=64, respectively, are discussed. Bands terminating at
higher and higher spin values are formed from successive proton excitations
across these shells. These bands show very different features depending on the
number of excited particles. Very good agreement with experiment is obtained.
Special emphasis is put on the formation of M1-bands in configurations with one
hole in the Z=64 core.


title: Shell Model applications to N=Z nuclei

abstract:
  This manuscript reviews recent results of large scale shell model
calculations on N=Z nuclei. The topics discussed include the role
proton-neutron pairing on the binding energies of pf-shell nuclei and his
influence on backbending rotors; coulomb energy differences and their
relationship with alignment. Proton-neutron correlations are found responsible
for the characteristic features of the isotopic shifts in calcium, the
parabolic dependence on A and the prominent odd-even staggering.


title:
Uncorrelated scattering approximation for the scattering and break-up of
  weakly bound nuclei on heavy targets

abstract:
  The scattering of a weakly bound (halo) projectile nucleus by a heavy target
nucleus is investigated. A new approach, called the Uncorrelated Scattering
Approximation, is proposed. The main approximation involved is to neglect the
correlation between the fragments of the projectile in the region where the
interaction with the target is important. The formalism makes use of
hyper-spherical harmonics, Raynal-Revay coefficients and momentum-localized
wave functions to expand projectile channel wave functions in terms of products
of the channel wave function of the individual fragments. Within this approach,
the kinetic energy and angular momentum of each fragment is conserved during
the scattering process. The elastic, inelastic and break-up S-matrices are
obtained as an analytic combination involving the bound wave function of the
projectile and the product of the S-matrices of the fragments. The approach is
applied to describe the scattering of deuteron on $^{58}$Ni at several
energies. The results are compared with experimental data and
continuum-discretized coupled-channels calculations.


title:
Effective hadron masses and couplings in nuclear matter and
  incompressibility

abstract:
  The role of effective hadron masses and effective couplings in nuclear matter
is studied using a generalized effective Lagrangian for sigma-omega model. A
simple relation among the effective masses, the effective couplings and the
incompressibility K is derived. Using the relation, it is found that the
effective repulsive and the effective attractive forces are almost canceled to
each other at the normal density. Inversely, if this cancellation is almost
complete, K should be 250-350MeV.


title: Why is the J/$\psi$ suppression enhanced at large transverse energy ?

abstract:
  We study the ratio of $J/\psi$ over minimum bias in $Pb$ $Pb$ collisions at
SPS energy. The NA50 data exhibit a sharp turn-over at $E_T \sim 100$ GeV
(close to the knee of the $E_T$ distribution) followed by a steady, steep
decrease at larger $E_T$. We show that this behaviour can be explained by the
combined effects of a small decrease of the hadronic $E_T$ in the $J/\psi$
event sample (due to the $E_T$ taken by the $J/\psi$ trigger), together with
the sharp decrease of the $E_T$ distributions in this $E_T$ region (tail). This
phenomenon does not affect the (true) ratio $J/\psi$ over $DY$ (obtained by the
NA50 standard analysis), but does affect the one obtained by the so-called
minimum bias analysis. A good agreement is obtained with the data coming from
both analysis -- as well as with the ratios of $J/\psi$ and $DY$ over minimum
bias -- in the whole $E_{T}$ region.


title: The Stability of Nuclear Matter in the Nambu-Jona-Lasinio Model

abstract:
  Using the Nambu-Jona-Lasinio model to describe the nucleon as a quark-diquark
state, we discuss the stability of nuclear matter in a hybrid model for the
ground state at finite nucleon density. It is shown that a simple extension of
the model to simulate the effects of confinement leads to a scalar
polarizability of the nucleon. This, in turn, leads to a less attractive
effective interaction between the nucleons, helping to achieve saturation of
the nuclear matter ground state. It is also pointed out that that the same
effect naturally leads to a suppression of ``Z-graph'' contributions with
increasing scalar potential.


title: Comprehensive calculations of three--body breakup cross sections

abstract:
  We present in detail a theoretical model for fragmentation reactions of
three--body halo nuclei. The different reaction mechanisms corresponding to the
different processes are described and discussed. Coulomb and nuclear
interactions are simultaneously included and the method is therefore applicable
for any target, light, intermediate and heavy. Absolute values of many
differential cross sections are then available as function of beam energy and
target. We apply the method to fragmentation of $^6$He and $^{11}$Li on C, Cu
and Pb. A large variety of observables, cross sections and momentum
distributions, are computed. In almost all cases we obtain good agreement with
the available experimental data.


title: Relativistic quark models

abstract:
  The application of relativistic constituent quark models to the evaluation of
the electromagnetic properties of the nucleon and its resonances is addressed.
The role of the pair creation process in the Feynmann triangle diagram is
discussed and the importance both of choosing the light-front formalism and of
using a Breit frame where the plus component of the four-momentum transfer is
vanishing, is stressed. The nucleon elastic form factors are calculated free of
spurious effects related to the loss of rotational covariance. The effect of a
finite constituent size is considered and the parameters describing the
constituent form factors are fixed using only the nucleon data up to Q**2 ~ 1
(GeV/c)**2; a constituent charge radius of ~ 0.45 fm is obtained in this way.
Above Q**2 ~ 1 (GeV/c)**2 our parameter-free predictions are in good agreement
with the experimental data, showing that soft physics may be dominant up to
Q**2 ~ 10 (GeV/c)**2. Our new results for the longitudinal and transverse
helicity amplitudes of the N - P_{11}(1440) transition are presented.


title:
Continuum Linear Response in Coordinate Space Hartree-Fock-Bogoliubov
  Formalism for Collective Excitations in Drip-line Nuclei

abstract:
  We formulate a continuum linear response theory on the basis of the
Hartree-Fock-Bogoliubov formalism in the coordinate space representation in
order to describe low-lying and high-lying collective excitations which couple
to one-particle and two-particle continuum states. Numerical analysis is done
for the neutron drip-line nucleus $^{24}$O. A low-lying collective mode that
emerges above the continuum threshold with large neutron strength is analyzed.
The collective state is sensitive to the density-dependence of the pairing. The
present theory satisfies accurately the energy weighted sum rule. This is
guaranteed by treating the pairing selfconsistently both in the static HFB and
in the dynamical linear response equation.