title: Pionic Modes Studied by Quasielastic (\vec{p}, \vec{n}) Reactions

abstract:
  It has long been expected that the pionic modes show some collective
phenomena such as the pion condensation in the high density nuclear matter and
its precursor phenomena in the ordinary nuclei. Here we show an evidence of the
precursor observed in the isovector spin longitudinal cross sections ID_q of
the quasielastic 12C, 40Ca (\vec{p}, \vec{n}) reactions at T_p = 346 and 494MeV
with the momentum transfer q = 1.7fm-1. Another aim of this report is to
evaluate the Landau-Migdal parameters g'_{NN}, g'_{N\Delta} and
g'_{\Delta\Delta} at the large momentum region from the above reactions. We
obtained g'_{NN} \approx 0.6-0.7, g'_{N\Delta} \approx 0.3-0.4. The results are
consistent with those at the small momentum region, which are obtained from the
Gamov-Teller strength distribution.


title:
The Separable Kernel of Nucleon-Nucleon Interaction in the
  Bethe-Salpeter Approach

abstract:
  The dispersion relations for nucleon-nucleon (NN) T-matrix in the framework
of Bethe-Salpeter equation for two spin one-half particle system and with
separable kernel of interaction are considered in the paper. The developed
expressions are applied for construction of the separable kernel of interaction
for S partial-waves in singlet and triplet channels. We calculate the low
energy scattering parameters and the phase shifts and also the deuteron binding
energy with the separable interaction. The approach can be easily extended to
higher partial-waves for NN-scattering and other reactions (anti N N-, pi
N-scattering).


title:
Renormalizing the Lippmann-Schwinger equation for the one pion exchange
  potential

abstract:
  We address the question whether the cut-off dependence, which has to be
introduced in order to properly define the Lippmann-Schwinger equation for the
one pion exchange potential plus local (delta-function) potentials, can be
removed (up to inverse powers of it) by a suitable tuning of the various (bare)
coupling constants. We prove that this is indeed so both for the spin singlet
and for the spin triplet channels. However, the latter requires such a strong
cut-off dependence of the coupling constant associated to the non-local term
which breaks orbital angular momentum conservation, that the renormalized
amplitude lacks from partial wave mixing. We argue that this is an indication
that this term must be treated perturbatively.


title: Collective multipole excitations in a microscopic relativistic approach

abstract:
  A relativistic mean field description of collective excitations of atomic
nuclei is studied in the framework of a fully self-consistent relativistic
random phase approximation (RRPA). In particular, results of RRPA calculations
of multipole giant resonances and of low-lying collective states in spherical
nuclei are analyzed. By using effective Lagrangians which, in the mean-field
approximation, provide an accurate description of ground-state properties, an
excellent agreement with experimental data is also found for the excitation
energies of low-lying collective states and of giant resonances. Two points are
essential for the successful application of the RRPA in the description of
dynamical properties of finite nuclei: (i) the use of effective Lagrangians
with non-linear terms in the meson sector, and (ii) the fully consistent
treatment of the Dirac sea of negative energy states.


title:
Spectroscopic amplitudes and microscopic substructure effects in nucleon
  capture reactions

abstract:
  Spectroscopic amplitudes play an important role in nuclear capture reactions.
These amplitudes are shown to include both single-particle and polarization
effects: the former through their spatial dependence and the latter through
their normalization (the spectroscopic factors). Coupled-channels equations are
developed for the spectroscopic amplitudes. These equations serve as a
convenient starting point for the derivation of several approximations:
Hartree, Hartree-Fock and two different single-particle models. The
single-particle models include antisymmetry in different ways, but both miss
many-body effects. Therefore, cross sections calculated with either of these
models need to be multiplied by the spectroscopic factor.


title: The Solar hep Process in Effective Field Theory

abstract:
  Using effective field theory, we calculate the S-factor for the hep process
in a totally parameter-free formulation. The transition operators are organized
according to chiral counting, and their matrix elements are evaluated using the
realistic nuclear wave functions obtained in the
correlated-hyperspherical-harmonics method. Terms of up to
next-to-next-to-next-to-leading order in heavy-baryon chiral perturbation
theory are considered. Fixing the only parameter in the theory by fitting the
tritium \beta-decay rate, we predict the hep S-factor with accuracy better than
\sim 20 %.


title: 11Li stability and its single particle structure

abstract:
  The stability of the 11Li exotic nucleus is discussed focusing on the
existence of single particle positive energy components in its ground state
structure. The existence of these continuum components is an outcome of many
models using the available experimental data of 10Li. We show that if this were
the case, the 11Li main decay mode could not be the beta decay.


title: In-medium nucleon-nucleon potentials in configuration space

abstract:
  Based on the thermodynamic Green function approach two-nucleon correlations
in nuclear matter at finite temperatures are revisited. To this end, we derive
phase equivalent effective $r$-space potentials that include the effect of the
Pauli blocking at a given temperature and density. These potentials enter into
a Schr\"odinger equation that is the $r$-space representation of the
Galitskii-Feynman equation for two nucleons. We explore the analytical
structure of the equation in the complex $k$-plane by means of Jost functions.
We find that despite the Mott effect the correlation with deuteron quantum
numbers are manifested as antibound states, i.e., as zeros of the Jost function
on the negative imaginary axis of the complex momentum space. The analysis
presented here is also suited for Coulombic systems.


title: Correlation search for coherent pion emission in heavy ion collisions

abstract:
  The methods allowing to extract the coherent component of pion emission
conditioned by the formation of a quasi-classical pion source in heavy ion
collisions are suggested. They exploit a nontrivial modification of the quantum
statistical and final state interaction effects on the correlation functions of
like and unlike pions in the presence of the coherent radiation. The extraction
of the coherent pion spectrum from pi+pi-, pi+pi+ and pi-pi- correlation
functions and single--pion spectra is discussed in detail for large expanding
systems produced in ultra-relativistic heavy ion collisions.


title:
Neutrinoless Double Beta Decay of Ge76, Se82, Mo100 and Xe136 to excited
  0^+ states

abstract:
  The neutrinoless double beta decay transition to the first excited 0^+
collective final state is examined for A=76, 82, 100 and 136 nuclei by assuming
light and heavy Majorana neutrino exchange mechanisms as well as the trilinear
R-parity violating contributions. Realistic calculations of nuclear matrix
elements have been performed within the renormalized quasiparticle random phase
approximation. Transitions to the first excited two-quadrupole phonon 0^+ state
are described within a boson expansion formalism and alternatively by using the
operator recoupling method. We present the sensitivity parameters to different
lepton number violating signals, which can be used in planning the neutrinoless
double beta decay experiments. The half-life of neutrinoless double beta decay
to the first excited state 0^+_1 is by a factor of 10 to 100 larger than that
of the transition to the ground state.


title: Pi0 photo- and electroproduction at threshold within a dynamical model

abstract:
  We show that, within a meson-exchange dynamical model describing most of the
existing pion electromagnetic production data up to the second resonance
region, one is also able to obtain a good agreement with the pi0 photo- and
electroproduction data near threshold. The potentials used in the model are
derived from an effective chiral Lagrangian. The only sizable discrepancy
between our results and the data is in the P-wave amplitude P3 = 2M1+ + M1-,
where our prediction underestimate the data by about 20%. In the case of pi0
production, the effects of final state interaction in the threshold region are
nearly saturated by single charge exchange rescattering. This indicates that in
ChPT it might be sufficient to carry out the calculation just up to one-loop
diagrams for threshold neutral pion production.


title:
Effects of Short-Range Correlations in (e,e'p) reactions and nuclear
  overlap functions

abstract:
  A study of the effects of short-range correlations over the (e,e'p) reaction
for low missing energy in closed shell nuclei is presented. We use correlated,
quasi-hole overlap functions extracted from the asymptotic behavior of the
one-body density matrix, containing central correlations of Jastrow type, up to
first-order in a cluster expansion, and computed in the very high asymptotic
region, up to 100 fm. The method to extract the overlap functions is checked in
a simple shell model, where the exact results are known. We find that the
single-particle wave functions of the valence shells are shifted to the right
due to the short-range repulsion by the nuclear core. The corresponding
spectroscopic factors are reduced only a few percent with respect to the shell
model. However, the (e,e'p) response functions and cross sections are enhanced
in the region of the maximum of the missing momentum distribution due to
short-range correlations.


title:
Polarization Observables in (${\vec e},e'{\vec N}N$) and (${\vec
  \gamma},{\vec N}N$) Reactions

abstract:
  Nucleon recoil polarization in electromagnetic reactions with two-nucleon
emission is discussed for both (${\vec e},e'{\vec N}N$) and
  (${\vec \gamma},{\vec N}N$). Numerical results are given for exclusive
two-nucleon knockout reactions from $^{16}$O in a theoretical model where
final-state interactions, one-body and two-body currents, and the effect of
correlations in the initial pair wave function are included.


title:
Approximations in Fusion and Breakup reactions induced by Radioactive
  Beams

abstract:
  Some commonly used approximations for complete fusion and breakup
transmission coefficients in collisions of weakly bound projectiles at near
barrier energies are assessed. We show that they strongly depend on the adopted
classical trajectory and can be significantly improved with proper treatment of
the incident and emergent currents in the WKB approximation.


title: Formation and decay of super heavy systems

abstract:
  We investigate the formation and the decay of heavy systems which are above
the fission barrier. By using a microscopic simulation of constraint molecular
dynamics (CoMD) on Au+Au collision, we observe composite states stay for very
long time before decaying by fission.


title: 3D real-space calculations of continuum response

abstract:
  We present linear response theories in the continuum capable of describing
continuum spectra and dynamical correlations of finite systems with no spatial
symmetry. Our formulation is essentially the same as the continuum random-phase
approximation (RPA) but suitable for uniform grid representation in the
three-dimensional (3D) Cartesian coordinate. Effects of the continuum are taken
into account by solving equations iteratively with a retarded Green's function.
The method is applied to photoabsorption spectra in small molecules (acetylene
and ethylene) and inelastic electron scattering from a deformed nucleus 12C.


title: Resonance and continuum states in weakly bound systems

abstract:
  Linear response theories in the continuum capable of describing continuum
spectra and dynamical correlations are presented. Our formulation is
essentially the same as the continuum random-phase approximation (RPA) but
suitable for uniform grid representation in the three-dimensional (3D)
Cartesian coordinate assuming no spatial symmetry. Effects of the continuum are
taken into account either by solving equations iteratively with a retarded
Green's function or by an absorbing boundary condition. The methods are applied
to giant resonances in a deformed nucleus 12C.


title:
Toroidal dipole resonances in the relativistic random phase
  approximation

abstract:
  The isoscalar toroidal dipole strength distributions in spherical nuclei are
calculated in the framework of a fully consistent relativistic random phase
approximation. It is suggested that the recently observed "low-lying component
of the isoscalar dipole mode" might in fact correspond to the toroidal giant
dipole resonance. Although predicted by several theoretical models, the
existence of toroidal resonances has not yet been confirmed in experiment. The
strong mixing between the toroidal resonance and the dipole compression mode
might help to explain the large discrepancy between theory and experiment on
the position of isoscalar giant dipole resonances.


title: Theoretical Conference Summary

abstract:
  This talk reviews progress reported at Quark-Matter 2001 on various
theoretical aspects of the quark-gluon plasma and discusses how the new results
obtained at RHIC change the standard picture of ultrarelativistic
nucleus-nucleus collisions.


title: Return of the EMC Effect

abstract:
  The relationship between the properties of nuclear matter and structure
functions measured in lepton-nucleus deep inelastic scattering is investigated
using light front dynamics. We find that relativistic mean field models such as
the Walecka, Zimanyi-Moszkowski (and point-coupling versions of the same) and
Rusnak-Furnstahl models contain essentially no binding effect, in accord with
an earlier calculation by Birse. These models are found to obey the
Hugenholtz-van Hove theorem, which is applicable if nucleons are the only
degrees of freedom. Any model in which the entire Fock space wave function can
be represented in terms of free nucleons must obey this theorem, which implies
that all of the plus momentum is carried by nucleons, and therefore that there
will be essentially no binding effect. The explicit presence of nuclear mesons
allows one to obtain a modified form of the Hugenholtz-van Hove theorem, which
is equivalent to the often-used momentum sum rule. These results argue in favor
of a conclusion that the depletion of the deep inelastic structure function
observed in the valence quark regime is due to some interesting effect
involving dynamics beyond the conventional nucleon-meson treatment of nuclear
physics.


title:
Regularized zero-range model and an application to the triton and the
  hypertriton

abstract:
  We examine the regularized zero-range model in an application to
three-fermion systems -- the triton and the hypertriton. We consider bound
states and low-energy neutron-deuteron and lambda-deuteron scattering. The
model is shown to provide an adequate quantitative description of these system
on a par with finite-range potential models. The well known correlation between
the doublet $nd$ scattering length and the triton binding energy (Phillips
line) finds a natural explanation within the model.


title:
Kaon photoproduction: background contributions, form factors and missing
  resonances

abstract:
  The photoproduction p(gamma, K+)Lambda process is studied within a
field-theoretic approach. It is shown that the background contributions
constitute an important part of the reaction dynamics. We compare predictions
obtained with three plausible techniques for dealing with these background
contributions. It appears that the extracted resonance parameters drastically
depend on the applied technique. We investigate the implications of the
corrections to the functional form of the hadronic form factor in the contact
term, recently suggested by Davidson and Workman (Phys. Rev. C 63, 025210). The
role of background contributions and hadronic form factors for the
identification of the quantum numbers of ``missing'' resonances is discussed.


title: Effective boost and "point-form" approach

abstract:
  Triangle Feynman diagrams can be considered as describing form factors of
states bound by a zero-range interaction. These form factors are calculated for
scalar particles and compared to point-form and non-relativistic results. By
examining the expressions of the complete calculation in different frames, we
obtain an effective boost transformation which can be compared to the
relativistic kinematical one underlying the present point-form calculations, as
well as to the Galilean boost. The analytic expressions obtained in this simple
model allow a qualitative check of certain results obtained in similar studies.
In particular, a mismatch is pointed out between recent practical applications
of the point-form approach and the one originally proposed by Dirac.


title:
A self-consistent quantal description of high-K states in the
  tilted-axis cranking model

abstract:
  A self-consistent and quantal description of high-$K$ bands is given in the
framework of the tilted-axis cranking model. (With a $\theta=90^{\circ}$ tilt
angle with respect to $x$-axis, this cranking model is equivalent to the
$z$-axis cranking.) The numerical results of the HFB calculations in this
framework are compared with experimental data for two quasi-particle excited
bands with $K^{\pi}=6^+$ in $^{178}$W.


title:
Resonance lifetime in Boltzmann-Uehling-Uhlenbeck theory: observable
  consequences

abstract:
  Within the transport BUU theory we study the influence of the choice for the
$\Delta$ resonance lifetime on pion-nucleus reactions and on heavy-ion
collisions at 1 A GeV. A quite small effect of these modifications on the pion
absorption on nuclei is found provided that the absorption probability of the
$\Delta$ resonance is modified consistently. Observable effects in the case of
heavy-ion collisions are demonstrated.


title:
Extracting forward strong amplitudes from elastic differential cross
  sections

abstract:
  The feasibility of a model-independent extraction of the forward strong
amplitude from elastic nuclear cross section data in the Coulomb-nuclear
interference region is assessed for $\pi$ and $K^+$ scattering at intermediate
energies. Theoretically-generated "data" are analyzed to provide criteria for
optimally designing experiments to measure these amplitudes, whose energy
dependence (particularly that of the real parts) is needed for disentangling
various sources of medium modifications of the projectile-nucleon interaction.
The issues considered include determining the angular region over which to make
the measurements, the role of the most forward angles measured, and the effects
of statistical and systematic errors. We find that there is a region near the
forward direction where Coulomb-nuclear interference allows reliable extraction
of the strong forward amplitude for both pions and the $K^+$ from .3 to 1
GeV/c.


title: QCD and Heavy Ions

abstract:
  This short paper is an attempt to describe a theorist's view of the goals of
relativistic heavy ion program which has just entered the collider era. These
goals are centered around understanding the properties and the critical
behavior of Quantum Chromo-Dynamics (QCD) in the non-linear regime of high
color field strength and high parton density. Some of the current theoretical
challenges are highlighted, and the place of heavy ion research in the broader
context of modern particle and nuclear physics is discussed.


title: Two-photon final states in peripheral heavy ion collisions

abstract:
  We discuss processes leading to two photon final states in peripheral heavy
ion collisions at RHIC. Due to the large photon luminosity we show that the
continuum subprocess $\gamma \gamma \to \gamma \gamma$ can be observed with a
large number of events. We study this reaction when it is intermediated by a
resonance made of quarks or gluons and discuss its interplay with the continuum
process, verifying that in several cases the resonant process ovewhelms the
continuum one. It is also investigated the possibility of observing a scalar
resonance (the $\sigma$ meson) in this process. Assuming for the $\sigma$ the
mass and total decay width values recently reported by the E791 Collaboration
we show that RHIC may detect this particle in its two photon decay mode if its
partial photonic decay width is of the order of the ones discussed in the
literature.


title: Two- and Three-photon Fusion in Relativistic Heavy ion Collisions

abstract:
  The production of mesons in ultra-peripheral collisions of relativistic heavy
ions is re-analyzed using a projection technique to calculate the amplitudes
for the appropriate Feynman diagrams. The virtuality of the exchanged photons
is fully accounted for in this approach. In the case of two-photon fusion, it
is explicitly shown that the inclusion of nuclear form factors validates the
equivalent photon approximation. However, this does not apply to three-photon
fusion cross sections. The cross section of J/\psi production in
ultra-peripheral collisions at RHIC and LHC are shown to be much smaller than
the cross sections for the production of C=even mesons of similar masses.


title:
The effect of surface and Coulomb interaction on the liquid-gas phase
  transition of finite nuclei

abstract:
  By means of the Furnstahl, Serot and Tang's model, the effects of surface
tension and Coulomb interaction on the liquid-gas phase transition for finite
nuclei are investigated. A limit pressure p-lim above which the liquid-gas
phase transition cannot take place has been found. It is found that comparing
to the Coulomb interaction, the contribution of surface tension is dominate in
low temperature regions. The binodal surface is also addressed.


title:
Space-time evolution and HBT analysis of relativistic heavy ion
  collisions in a chiral SU(3) x SU(3) model

abstract:
  The space-time dynamics and pion-HBT radii in central heavy ion-collisions at
CERN-SPS and BNL-RHIC are investigated within a hydrodynamic simulation. The
dependence of the dynamics and the HBT-parameters on the EoS is studied with
different parametrisations of a chiral SU(3) sigma-omega model. The
selfconsistent collective expansion includes the effects of effective hadron
masses, generated by the nonstrange and strange scalar condensates. Different
chiral EoS show different types of phase transitions and even a crossover. The
influence of the order of the phase transition and of the difference in the
latent heat on the space-time dynamics and pion-HBT radii is studied. A small
latent heat, i.e. a weak first-order chiral phase transition, or even a smooth
crossover leads to distinctly different HBT predictions than a strong first
order phase transition. A quantitative description of the data, both at SPS
energies as well as at RHIC energies, appears difficult to achieve within the
ideal hydrodynamical approach using the SU(3) chiral EoS. A strong first-order
quasi-adiabatic chiral phase transition seems to be disfavored by the pion-HBT
data from CERN-SPS and BNL-RHIC.


title:
The Magnetic Moments of the Octet Baryons in Quenched Chiral
  Perturbation Theory

abstract:
  We compute the magnetic moments of the octet baryons up to two orders in
quenched chiral perturbation theory. In addition to the $\sim\sqrt{m_q}$
contributions that arise in QCD, there are lower-order contributions of the
form $M_0^2\log m_q$ from loop diagrams involving hairpin interactions.


title:
The relativistic continuum Hartree-Bogoliubov description of
  charge-changing cross section for C,N,O and F isotopes

abstract:
  The ground state properties including radii, density distribution and one
neutron separation energy for C, N, O and F isotopes up to the neutron drip
line are systematically studied by the fully self-consistent microscopic
Relativistic Continuum Hartree-Bogoliubov (RCHB) theory. With the proton
density distribution thus obtained, the charge-changing cross sections for C,
N, O and F isotopes are calculated using the Glauber model. Good agreement with
the data has been achieved. The charge changing cross sections change only
slightly with the neutron number except for proton-rich nuclei. Similar trends
of variations of proton radii and of charge changing cross sections for each
isotope chain is observed which implies that the proton density plays important
role in determining the charge-changing cross sections.


title: Isospin and Z$^{1/3}$ Dependence of the Nuclear Charge Radii

abstract:
  Based on the systematic investigation of the data available for $A \geq 40$,
a $Z^{1/3}$ dependence for the nuclear charge radii is shown to be superior to
the generally accepted $A^{1/3}$ law. A delicate scattering of data around
$R_c/Z^{1/3}$ is infered as owing to the isospin effect and a linear dependence
of $R_c/Z^{1/3}$ on $N/Z$ (or $(N-Z)/2$) is found. This inference is well
supported by the microscopic Relativistic Continuum Hartree-Bogoliubov (RCHB)
calculation conducted for the proton magic Ca, Ni, Zr, Sn and Pb isotopes
including the exotic nuclei close to the neutron drip line. With the linear
isospin dependence provided by the data and RCHB theory, a new isospin
dependent $Z^{1/3}$ formula for the nuclear charge radii is proposed.


title: Parity Violation in Neutron Capture Reactions

abstract:
  In the last decade, the scattering of polarized neutrons on compound nucleus
resonances proved to be a powerful experimental technique for probing nuclear
parity violation. Longitudinal analyzing powers in neutron transmission
measurements on p-wave resonances in nuclei such as $^{139}$La and $^{232}$Th
were found to be as large as 10%. Here we examine the possibilities of carrying
out a parallel program to measure asymmetries in the $(n,\gamma$) reaction on
these same compound nuclear resonances. Symmetry-violating $(n,\gamma$) studies
can also show asymmetries as large as 10%, and have the advantage over
transmission experiments of allowing parity-odd asymmetries in several
different gamma-decay branches from the same resonance. Thus, studies of parity
violation in the $(n,\gamma)$ reaction using high efficiency germanium
detectors at the Los Alamos Lujan facility, for example, could determine the
parity-odd nucleon-nucleon matrix elements in complex nuclei with high
accuracy. Additionally, simultaneous studies of the E1 and $V_{PNC}$ matrix
elements invol ved in these decays could be used to help constrain the
statistical theory of parity non-conservation in compound nuclei.


title:
Approximate boost of the relativistic two-body problem in instant
  formalism

abstract:
  Considering two spinless particles, a simple, approximate boost rule is
derived that is sufficient to keep the mass invariant and to relate
interactions, vertex functions, wave functions and t-matrices of the instant
two-body problem in an arbitrary frame to those in the c.m. frame. The boost
generator ${\bf K}$ that is used provides a solution to the Poincar\'{e}
algebra except for the commutator between two components of ${\bf K}$, for
which it provids an approximate solution.


title:
Doublet channel neutron-deuteron scattering in leading order effective
  field theory

abstract:
  The doublet channel neutron-deuteron scattering amplitude is calculated in
leading order effective field theory (EFT). It is shown that this amplitude
does not depend on a constant contact interaction three-body force.
Satisfactory agreement with available data is obtained when only two-body
forces are included.


title:
Structure of Light Unstable Nuclei Studied with Antisymmetrized
  Molecular Dynamics

abstract:
  Structures of light unstable nuclei, Li, Be, B, and C isotopes are
systematically studied with a microscopic method of antisymmetrized molecular
dynamics. The theoretical method is found to be very useful to study ground and
excited states of various nuclei covering unstable nuclei. The calculations
succeed to reproduce many experimental data for nuclear structures; energies,
radii, magnetic dipole moments, electric quadrupole moments, transition
strength. In the theoretical results it is found that various exotic phenomena
in unstable nuclei such as molecular-like structures, neutron skin, and large
deformations may appear in unstabel nuclei. We investigate the structure change
with the increase of neutron number and with the increase of the excitation
energies, and find the drastic changes between shell-model-like structures and
clustering structures. The mechanism of clustering developments in unstable
nuclei are discussed.


title: Quark effects and isospin-violation in ${}1S_0$ NN scattering

abstract:
  We present the results of the effects of various mechanisms on the quark
level, including QED-QCD interference effect, on isospin violation in ${}1S_0$
NN scatterings with the new sets of strength parameters obtained by fitting to
mass splittings in the baryon isomultiplets listed in the most recent PDG
compilation. We also give the matrix elements of the various potential
operators which would be useful to study of these charge dependent effects in
finite nuclei.


title: The rho meson in nuclear matter - a chiral unitary approach

abstract:
  In this work, the properties of the $\rho$ meson at rest in cold symmetric
nuclear matter are studied. We make use of a chiral unitary approach to
pion-pion scattering in the vector-isovector channel, calculated from the
lowest order Chiral Perturbation Theory ($\chi PT$) lagrangian including
explicit resonance fields. Low energy chiral constraints are considered by
matching our expressions to those of one loop $\chi PT$. To account for the
medium corrections, the $\rho$ couples to $\pi\pi$ pairs which are properly
renormalized in the nuclear medium, accounting for both $p-h$ and $\Delta -h$
excitations. The terms where the $\rho$ couples directly to the hadrons in the
$p-h$ or $\Delta-h$ excitations are also accounted for. In addition, the $\rho$
is also allowed to couple to $N^{*}(1520)-h$ components.


title:
Isospin Symmetry Breaking within the HLS Model: A Full ($\rho, \omega,
  \phi$) Mixing Scheme

abstract:
  We study the way isospin symmetry violation can be generated within the
Hidden Local Symmetry (HLS) Model. We show that isospin symmetry breaking
effects on pseudoscalar mesons naturally induces correspondingly effects within
the physics of vector mesons, through kaon loops. In this way, one recovers all
features traditionally expected from $\rho-\omg$ mixing and one finds support
for the Orsay phase modelling of the $e^+e^- \ra \pi^+ \pi^-$ amplitude. We
then examine an effective procedure which generates mixing in the whole $\rho$,
$\omg$, $\phi$ sector of the HLS Model. The corresponding model allows us to
account for all two body decays of light mesons accessible to the HLS model in
modulus and phase, leaving aside the $\rho \ra \pi \pi$ and $K^* \ra K \pi$
modes only, which raise a specific problem. Comparison with experimental data
is performed and covers modulus and phase information; this represents 26
physics quantities successfully described with very good fit quality within a
constrained model which accounts for SU(3) breaking, nonet symmetry breaking in
the pseudoscalar sector and, now, isospin symmetry breaking.


title:
Single-Particle Transfer and Nuclear Supersymmetry. Pick-Up and
  Stripping with SUSY

abstract:
  Transfer reactions constitute a stringent test for nuclear supersymmetry, a
theory that simultaneously describes neighboring nuclei with bosonic and
fermionic character. We construct and analytically evaluate one-nucleon
transfer matrix elements between supersymmetric partners with the U(6/4) case
as an example, and stress the need for a careful treatment of bosonic and
fermionic operators in the construction of mixed tensor operators.


title:
$\Xi^-$ emission probabilities at $(K^-,K^+)$ reaction points and the
  $\Xi N$ interaction

abstract:
  $\Xi^-$ escaping and scattering probabilities in the $(K^-,K^+)$ reaction
with nuclear targets is investigated on the basis of the eikonal approximation.
Calculations are performed using the $S=-2$ sector of the Nijmegen model-D
interaction, whose hard core radii are treated phenomenologically. %The $\Xi^-
N$, $\Xi^- p$ and $\Xi^- n$ elastic cross sections are The $\Xi^- N$ elastic
cross sections are derived from the $^9$Be$(K^-,K^+)$ data of the BNL-E906
experiment, which is useful to determine the hard-core radii in $P$-states. The
$\Xi$ single-particle potential energy is investigated with the G-matrix
calculation in nuclear matter, which is sensitive to the hard-core radii in
$S$-states. The important constraint for the $\Xi N$ interaction is obtained by
combining the two analyses.


title: Evidence for partial chiral symmetry restoration from pionic atoms

abstract:
  Extensive data on strong interaction effects in pionic atoms are analyzed
with a density-dependent isovector scattering amplitude suggested recently by
Weise to result from a density dependence of the pion decay constant. Most of
the so-called `missing s-wave repulsion' is removed when adopting this
approach, thus indicating a partial chiral symmetry restoration in dense
matter. The resulting potentials describe quite well also elastic scattering of
20 MeV pions on Ca. Further tests with elastic scattering are desirable.


title: Wobbling motion coupled to gamma vibration at high spin

abstract:
  We report a solution of the tilted-axis cranked HFB equation for $^{164}$Hf,
which shows wobbling motion coupled to gamma vibration at high spin ($J\simeq
60\hbar$). Possible anharmonicity and splitting of energy levels are also
discussed as a consequence of the wobbling motion with large amplitude.


title: Relativistic corrections in (gamma,N) knockout reactions

abstract:
  We develop a fully relativistic DWIA model for photonuclear reactions using
the relativistic mean field theory for the bound state and the Pauli reduction
of the scattering state which is calculated from a relativistic optical
potential. Results for the 12C(gamma,p) and 16O(gamma,p) differential cross
sections and photon asymmetries are displayed in a photon energy range between
60 and 257 MeV, and compared with nonrelativistic DWIA calculations. The
effects of the spinor distortion and of the effective momentum approximation
for the scattering state are discussed. The sensitivity of the model to
different prescriptions for the one-body current operator is investigated. The
off-shell ambiguities are large in (gamma,p) calculations, and even larger in
(gamma,n) knockout.


title:
A method of implementing Hartree-Fock calculations with zero- and
  finite-range interactions

abstract:
  We develop a new method of implementing the Hartree-Fock calculations. A
class of Gaussian bases is assumed, which includes the Kamimura-Gauss basis-set
as well as the set equivalent to the harmonic-oscillator basis-set. By using
the Fourier transformation to calculate the interaction matrix elements, we can
treat various interactions in a unified manner, including finite-range ones.
The present method is numerically applied to the spherically-symmetric
Hartree-Fock calculations for the oxygen isotopes with the Skyrme and the Gogny
interactions, by adopting the harmonic-oscillator, the Kamimura-Gauss and a
hybrid basis-sets. The characters of the basis-sets are discussed. Adaptable to
slowly decreasing density distribution, the Kamimura-Gauss set is suitable to
describe unstable nuclei. A hybrid basis-set of the harmonic-oscillator and the
Kamimura-Gauss ones is useful to accelerate the convergence, both for stable
and unstable nuclei.


title:
Magic numbers in exotic nuclei and spin-isospin properties of {\it NN}
  interaction

abstract:
  The magic numbers in exotic nuclei are discussed, and their novel origin is
shown to be the spin-isospin dependent part of the nucleon-nucleon interaction
in nuclei. The importance and robustness of this mechanism is shown in terms of
meson exchange, G-matrix and QCD theories. In neutron-rich exotic nuclei, magic
numbers such as N = 8, 20, etc. can disappear, while N = 6, 16, etc. arise,
affecting the structure of lightest exotic nuclei to nucleosynthesis of heavy
elements.


title: In medium T-matrix for superfluid nuclear matter

abstract:
  We study a generalized ladder resummation in the superfluid phase of the
nuclear matter. The approach is based on a conserving generalization of the
usual T-matrix approximation including also anomalous self-energies and
propagators. The approximation here discussed is a generalization of the usual
mean-field BCS approach and of the in medium T-matrix approximation in the
normal phase. The numerical results in this work are obtained in the
quasi-particle approximation. Properties of the resulting self-energy,
superfluid gap and spectral functions are studied.


title: Transition to meson-dominated matter at RHIC. Consequences for kaon flow

abstract:
  Anisotropic flow of kaons and antikaons is studied in heavy-ion collisions at
CERN SPS and BNL RHIC energies within the microscopic quark-gluon string model.
In the midrapidity range the directed flow of kaons v_1 differs considerably
from that of antikaons at SPS energy (E_{lab} = 160 AGeV), while at RHIC energy
(\sqrt{s} = 130 AGeV) the excitation functions of both, kaon and antikaon,
flows coincide within the statistical error bars. The change is attributed to
formation of dense meson-dominated matter at RHIC, where the differences in
interaction cross-sections of kaons and antikaons become unimportant. The time
evolution of the kaon anisotropic flow is also investigated. The elliptic flow
of these hadrons is found to develop at midrapidity at times 3 < t < 10 fm/c,
which is much larger than the nuclear passing time t^{pass} = 0.12 fm/c. As a
function of transverse momentum the elliptic flow increases almost linearly
with rising p_t. It stops to rise at p_t > 1.5 GeV/c reaching the saturation
value $v_2^K (p_t) \approx 10%$.


title:
Chiral Symmetry and the Nucleon-Nucleon Interaction: Developing an
  Accurate NN Potential Based upon Chiral Effective Field Theory

abstract:
  We present an accurate nucleon-nucleon (NN) potential based upon chiral
effective Lagrangians. The model includes one- and two-pion exchange
contributions up to chiral order three and contact terms (which represent the
short range force) up to order four. Within this framework, the NN phase shifts
below 300 MeV lab. energy and the properties of the deuteron are reproduced
with high-precision. This chiral NN potential may serve as a reliable starting
point for testing the chiral effective field theory approach in exact
few-nucleon and microscopic nuclear many-body calculations.


title: Charmonium absorption cross section by nucleon

abstract:
  The $J/\psi$ absorption cross section by nucleon is studied using a gauged
SU(4) hadronic Lagrangian but with empirical particle masses, which has been
used previously to study the $J/\psi$ absorption cross section by pion and rho
meson. Including both two-body and three-body final states, we find that with a
cutoff parameter of 1 GeV at interaction vertices involving charm hadrons, the
$J/\psi-N$ absorption is at most 5 mb and is consistent with that extracted
from $J/\psi$ production from both photo-nuclear and proton-nucleus reactions.


title: Quark Model study of the NN*(1440) components on the deuteron

abstract:
  We present a calculation of the deuteron wave function including $NN$,
$\Delta\Delta$, and $NN^*$(1440) channels. All the transition potentials, as
well as the direct $NN$ potential, have been obtained from the same underlying
quark model using standard techniques available in the literature. The
calculated weights for the different channels are in agreement with previous
theoretical estimations.


title: Quark model study of the triton bound stat

abstract:
  The three-nucleon bound state problem is studied employing nucleon-nucleon
potentials derived from a basic quark-quark interaction. We analyze the effects
of the nonlocalities generated by the quark model. The calculated triton
binding energies indicate that quark-model nonlocalities can yield additional
binding in the order of few hundred keV.


title:
Unified description of three positive and three negative parity
  interacting bands

abstract:
  The coherent state model (CSM) is extended so that three negative parity
bands are treated on equal footing with three positive parity bands. The six
rotational bands are generated by projecting out angular momenta and parities
from three intrisic orthogonal states which exhibit both quadrupole and
octupole deformations. The projected states are, by construction, mutually
orthogonal. In the space of projected states, a sub-space of a quadrupole and
octupole multi-boson states, an effective quadrupole and octupole boson
Hamiltonian is solved. The eigenstates of the model Hamiltonian are linked by
multipole transition operators for which lowest order boson expressions are
considered. The calculations involve 6 structure coefficients and two
deformation parameters. All of them are fixed by a least square fit of the
known experimental energies. Applications are made to Gd158, Yb172, Ra218,
Ra226, Th232, U238, Pu238. Very good agreement is obtained for both excitation
energies and transition probabilities. New signatures for octupole deformation,
manifested in excited bands, are pointed out.


title:
Production mechanism of hot nuclei in violent collisions in the Fermi
  energy domain

abstract:
  A production mechanism of highly excited nuclei formed in violent collisions
in the Fermi energy domain is investigated. The collision of two nuclei is
decomposed into several stages which are treated separately. Simplified exciton
concept is used for the description of pre-equilibrium emission. A modified
spectator-participant scenario is used where motion along classical Coulomb
trajectories is assumed. The participant and one of the spectator zones undergo
incomplete fusion. Excitation energies of both cold and hot fragment are
determined. Results of the calculation are compared to recent experimental data
in the Fermi energy domain. Data on hot projectile-like, mid-velocity and
fusion-like sources are described consistently. Geometric aspects of
pre-equilibrium emission are revealed. Explanations to previously unexplained
experimental phenomena are given. Energy deposited into non-thermal degrees of
freedom is estimated.


title:
A Theoretical Study of $\rho^{0}$-Photoproduction on Nucleons near
  Threshold

abstract:
  We investigate the possibility that the process of $\rho^{0}$-meson
photoproduction on proton, $\gamma+p\to p+\rho^{0}$, in the near threshold
region $E_{\gamma}< 2$ GeV, can be considered in the framework of model with
$\pi$-, $\sigma$- and N-exchanges. This suggestion is based on a study of the
t-dependence of differential cross section, $d\sigma(\gamma p \to p
\rho^{0})/dt$, which has been measured by SAPHIR Collaboration. We find that
the suggested model provides a good description of the experimental data with
new values of $\rho NN$-coupling constants in the region of the time-like
$\rho^{0}$-meson momentum. Our results suggest that such model can be
considered as a suitable nonresonant background mechanism for the future
discussion of possible role of nucleon resonance contributions. Our predictions
for $\rho^{0}$-meson photoproduction on neutron target and for beam asymmetry
on both proton and neutron targets are presented.


title: Chiral $2\pi$-exchange NN-potentials: Two-loop contributions

abstract:
  We calculate in heavy baryon chiral perturbation theory the local
NN-potentials generated by the two-pion exchange diagrams at two-loop order. We
give explicit expressions for the mass-spectra (or imaginary parts) of the
corresponding isoscalar and isovector central, spin-spin and tensor
NN-amplitudes. We find from two-loop two-pion exchange a sizeable isoscalar
central repulsion which amounts to $62.3 $MeV at $r=1.0 $fm. There is a
similarly strong isovector central attraction which however originates mainly
from the third order low energy constants $\bar d_j$ entering the chiral $\pi
N$-scattering amplitude. We also evaluate the one-loop $2\pi$-exchange diagram
with two second order chiral $\pi \pi NN$-vertices proportional to the low
energy constants $c_{1,2,3,4}$ as well as the first relativistic 1/M-correction
to the $2\pi$-exchange diagrams with one such vertex. The diagrammatic results
presented here are relevant components of the chiral NN-potential at
next-to-next-to-next-to-leading order.


title: Relativistic effects and quasipotential equations

abstract:
  We compare the scattering amplitude resulting from the several quasipotential
equations for scalar particles. We consider the Blankenbecler-Sugar, Spectator,
Thompson, Erkelenz-Holinde and Equal-Time equations, which were solved
numerically without decomposition into partial waves. We analyze both
negative-energy state components of the propagators and retardation effects. We
found that the scattering solutions of the Spectator and the Equal-Time
equations are very close to the nonrelativistic solution even at high energies.
The overall relativistic effect increases with the energy. The width of the
band for the relative uncertainty in the real part of the scattering $T$
matrix, due to different dynamical equations, is largest for
backward-scattering angles where it can be as large as 40%.


title: Many-body Theory at Extreme Isospin

abstract:
  The structure of nuclei far off beta-stability is investigated by nuclear
many-body theory. In-medium interactions for asymmetric nuclear matter are
obtained by (Dirac-) Brueckner theory thus establishing the link of nuclear
forces to free space interactions. HFB and RPA theory is used to describe
ground and excited states of nuclei from light to heavy masses. In extreme
dripline systems pairing and core polarization are found to be most important
for the binding, especially of halo nuclei. The calculations show that far off
stability mean-field dynamics is gradually replaced by dynamical correlations,
giving rise to the dissolution of shell structures.


title:
(e,e'N) and (e,e'NN) experiments at NIKHEF, Mainz and JLab and open
  problems in one- and two-nucleon emission

abstract:
  A critical review is presented of recent data on direct one- and two-nucleon
emission obtained in electron scattering at NIKHEF, Mainz and JLab. In the case
of (e,e$'$p) reactions attention is focussed on extracting spectroscopic
factors, looking at medium effects on the bound nucleon form factors, and
investigating nuclear transparency. The possibility of obtaining information on
nucleon-nucleon correlations in (e,e$'$pp) and (e,e$'$pn) reactions is also
discussed.


title:
Single particle properties of Lambda hypernuclei in the density
  dependent relativistic hadron field theory

abstract:
  The density dependent relativistic hadron field theory is used to describe
single particle properties of Lambda hypernuclei. The discussion focuses on the
spin-orbit systematics in the relativistic mean-field formalism by discussing
general effects of the Lambda continuum threshold and the delocalization of the
Lambda wave function. Theoretical predictions for the hypernuclear Auger effect
are presented.


title:
Consistent one-pion exchange currents in electron scattering from a
  relativistic Fermi gas

abstract:
  A set of fully relativistic one-pion-exchange electromagnetic operators is
developed for use in one-particle emission reactions induced by electrons. To
preserve the gauge invariance of the theory additional pionic correlation
operators are required beyond the usual meson-exchange current operators. Of
these, in the present work emphasis is placed on the self-energy current which
is infinite and needs to be renormalized. The renormalized current is expanded
to first order to obtain a genuine one-pion-exchange contribution to the
inclusive responses.


title: Diomega production in relativistic heavy ion collisions

abstract:
  Using a multiphase transport model, we study the production of a new strange
dibaryon (\Omega\Omega)_{0+} in dense hadronic matter formed in relativistic
heavy ion collisions. The (multi-)strange baryons (\Xi and \Omega) are produced
by strangeness-exchange reactions between antikaons and hyperons in the pure
hadronic phase. The rescattering between the omegas at midrapidity leads to a
production probability of \simeq 3x10^{-7} (\Omega\Omega)_{0+} per event at the
RHIC energy of \sqrt s=130A GeV. The production probability would be enhanced
by two orders of magnitude if (\Omega\Omega)_{0+} and omega reach chemical
equilibrium during heavy ion collisions. We further find that the yield of
(\Omega\Omega)_{0+} increases continuously from SPS to the highest RHIC energy.


title: Production of $a_0$-mesons in pp and pn reactions

abstract:
  We investigate the cross section for the reaction $NN \to NNa_0$ near
threshold and at medium energies. An effective Lagrangian approach with
one-pion exchange is applied to analyze different contributions to the cross
section for different isospin channels. The Reggeon exchange mechanism is also
considered. The results are used to calculate the contribution of the $a_0$
meson to the cross sections and invariant $K \bar K$ mass distributions of the
reactions $pp\to pn K^+\bar K^0$ and $pp\to pp K^+K^-$. It is found that the
experimental observation of $a_0^+$ mesons in the reaction $pp\to pn K^+\bar
K^0$ is much more promising than the observation of $a_0^0$ mesons in the
reaction $pp\to pp K^+K^-$.


title: Two-body relaxation times in heated nuclei

abstract:
  The retardation and temperature effects in two-body collisions are studied.
The collision integral with retardation effects is obtained on the base of the
Kadanoff- Baym equations for Green functions in a form with allowance for
reaching the local equilibrium system. The collisional relaxation times of
collective vibrations are calculated using both the transport approach and
doorway state mechanism with hierarchy of particle-hole configurations in
heated nuclei. The relaxation times of the kinetic method are rather slowly
dependent on multipolarity of the Fermi surface distortion and mode of the
collective motion. The dependence of the relaxation times on temperature as
well as on frequency of collective vibrations is considered and compared. It is
shown that variations of the in-medium two-body cross-sections with energy lead
to non-quadratic dependence of the collisional relaxation time both on
temperature and on collective motion frequency.


title:
Kinematical versus dynamical relativistic effects in
  A(\vec{e},e'\vec{p})B

abstract:
  The relativistic mean field approach is applied to the description of
coincidence $A(e,e'p)B$ reactions where both the incident electron beam and
knockout proton are polarized. Effects introduced by the dynamical enhancement
of the lower components of the bound nucleon wave function are analyzed within
RPWIA for the polarized responses and transferred polarizations. Results
obtained by projecting out the negative-energy components are also compared
with various nonrelativistic reductions.


title:
The low-energy nuclear density of states and the saddle point
  approximation

abstract:
  The nuclear density of states plays an important role in nuclear reactions.
At high energies, above a few MeV, the nuclear density of states is well
described by a formula that depends on the smooth single particle density of
states at the Fermi surface, the nuclear shell correction and the pairing
energy. In this paper we present an analysis of the low energy behaviour of the
nuclear density of states using the saddle point approximation and extensions
to it. Furthermore, we prescribe a simple parabolic form for excitation energy,
in the low energy limit, which may facilitate an easy computation of level
densities.


title:
Inelastic scattering of protons from $^{6,8}$He and $^{7,11}$Li in a
  folding model approach

abstract:
  The proton-inelastic scattering from $^{6,8}$He and $^{7,11}$Li nuclei are
studied in a folding model approach. A finite-range, momentum, density and
isospin dependent nucleon-nucleon interaction (SBM) is folded with realistic
density distributions of the above nuclei. The renormalization factors N$_R$
and N$_I$ on the real and volume imaginary part of the folded potentials are
obtained by analyzing the respective elastic scattering data and kept unaltered
for the inelastic analysis at the same energy. The form factors are generated
by taking derivatives of the folded potentials and therefore required
renormalizations. The $\beta$ values are extracted by fitting the p +
$^{6,8}$He,$^{7,11}$Li inelastic angular distributions. The present analysis of
p + $^8$He inelastic scattering to the 3.57 MeV excited state, including
unpublished forward angle data (RIKEN) confirms L = 2 transition. Similar
analysis of the p + $^6$He inelastic scattering angular distribution leading to
the 1.8 MeV (L = 2) excited state fails to satisfactorily reproduce the data.


title: The mean energy, strength and width of triple giant dipole resonances

abstract:
  We investigate the mean energy, strength and width of the triple giant dipole
resonance using sum rules.


title:
Energy and centrality dependences of charged multiplicity density in
  relativistic nuclear collisions

abstract:
  Using a hadron and string cascade model, JPCIAE, the energy and centrality
dependences of charged particle pseudorapidity density in relativistic nuclear
collisions were studied. Within the framework of this model, both the
relativistic $p+\bar p$ experimental data and the PHOBOS and PHENIX $Au+Au$
data at $\sqrt s_{nn}$=130 GeV could be reproduced fairly well without retuning
the model parameters. The predictions for full RHIC energy $Au+Au$ collisions
and for $Pb+Pb$ collisions at the ALICE energy were given. Participant nucleon
distributions were calculated based on different methods. It was found that the
number of participant nucleons, $<N_{part}>$, is not a well defined variable
both experimentally and theoretically. Therefore, it is inappropriate to use
charged particle pseudorapidity density per participant pair as a function of
$<N_{part}>$ for distinguishing various theoretical models.


title: Is early thermalization achieved only near midrapidity at RHIC ?

abstract:
  The pseudorapidity dependence of elliptic flow in Au+Au collisions at 130 $A$
GeV is studied within a full three-dimensional hydrodynamic model in the
light-cone coordinate. First, we prepare two initial conditions in the
hydrodynamic model for analyzing elliptic flow. Both initial conditions lead to
reasonable agreement with single particle spectra in central and semi-central
collisions. Next, by using these hydrodynamic simulations, we compare elliptic
flow as a function of pseudorapidity with experimental data recently measured
by the PHOBOS Collaboration. Our results are in agreement with experimental
data only near midrapidity. This suggests that thermalization in the early
stage of collisions is not achieved in forward and backward rapidity regions.


title:
Renormalization of ${}^1S_0$ NN scattering amplitude in effective field
  theory

abstract:
  Cutoff regularized subleading order ${}^1S_0$ NN potential of effective field
theory (EFT) is iterated using Lippmann-Schwinger equation. It is shown that
the scattering amplitudes calculated in cutoff and subtractively renormalized
EFT are equal up to the accuracy of performed calculations. Non-perturbative
renormalization, where part of divergences are absorbed into two contact
interaction coupling constants with subsequent removal of regularization is
also performed. Cutoff and dimensional regularizations both lead to finite but
different results within this scheme.


title: Manifestations of high density QCD in the first RHIC data

abstract:
  We derive a simple analytical scaling function which embodies the predictions
of high density QCD on the energy, centrality, rapidity, and atomic number
dependences of hadron multiplicities in nuclear collisions. Both centrality and
rapidity dependences of hadron multiplicity in $Au-Au$ collisions as measured
at RHIC at $\sqrt{s}= 130 {GeV}$ are well described in this approach. The
centrality and rapidity dependences of hadron multiplicity at $\sqrt{s}= 200 \
{GeV}$ run at RHIC are predicted; the variation of these dependences with
energy appear different from other approaches, and can be used as an important
test of the ideas based on parton saturation and classical Chromo-Dynamics.


title: The nuclear Schiff moment and time invariance violation in atoms

abstract:
  Parity and time invariance violating (P,T-odd) nuclear forces produce P,T-odd
nuclear moments. In turn, these moments can induce electric dipole moments
(EDMs) in atoms through the mixing of electron wavefunctions of opposite
parity. The nuclear EDM is screened by atomic electrons. The EDM of an atom
with closed electron subshells is induced by the nuclear Schiff moment.
Previously the interaction with the Schiff moment has been defined for a
point-like nucleus. No problems arise with the calculation of the electron
matrix element of this interaction as long as the electrons are considered to
be non-relativistic. However, a more realistic model obviously involves a
nucleus of finite-size and relativistic electrons. In this work we have
calculated the finite nuclear-size and relativistic corrections to the Schiff
moment. The relativistic corrections originate from the electron wavefunctions
and are incorporated into a ``nuclear'' moment, which we term the local dipole
moment. For mercury these corrections amount to about 25%. We have found that
the natural generalization of the electrostatic potential of the Schiff moment
for a finite-size nucleus corresponds to an electric field distribution which,
inside the nucleus, is well approximated as constant and directed along the
nuclear spin, and outside the nucleus is zero. Also in this work the plutonium
atomic EDM is estimated.


title: Nuclear Matter Spectral Functions by Transport Theory

abstract:
  Quantum transport theory is used to calculate the nucleon spectral function
in infinite nuclear matter. A self-consistent description is obtained by
utilizing the relations between collision rates and correlation functions.
Static and dynamical self-energies are taken into account in the single
particle propagators. The real parts of the non-static self-energy
contributions are calculated by dispersion theory thus conserving the
analyticity of momentum distributions. The transport theoretical spectral
functions, momentum distributions, occupation probabilities and responce
functions are in close agreement with results of variational and other
many-body theoretical calculations. The results indicate that the nucleon
spectral functions are determined only by the average short-range correlation
strength.


title:
A Role of the Axial Vector Mesons on the Photon Production in Heavy Ion
  Collisions and Their Relevant Decays

abstract:
  A role of the axial vector mesons, such as $K_1$ and $a_1$, on the emitted
photon spectrum in hot hadronic matter is studied through the channels $\pi
\rho \to a_1 \to \pi \gamma$ and $K \rho \to K_1 \to K \gamma$. They are shown
to be dominant channels in this spectrum. This study is carried out with an
effective chiral lagrangian which includes vector and axial-vector mesons and
explains well their relevant decays simultaneously.


title: Nuclear mean field from chiral pion-nucleon dynamics

abstract:
  Using the two-loop approximation of chiral perturbation theory, we calculate
the momentum and density dependent single particle potential of nucleons in
isospin-symmetric nuclear matter. The contributions from one- and two-pion
exchange diagrams give rise to a potential depth for a nucleon at rest of
$U(0,k_{f0}) = -53.2 $MeV at saturation density. The momentum dependence of the
real part of the single particle potential $U(p,k_{f0})$ is non-monotonic and
can be translated into a mean effective nucleon mass of $\bar M^* \simeq 0.8
M$. The imaginary part of the single particle potential $W(p,k_f)$ is generated
to that order entirely by iterated one-pion exchange. The resulting half width
of a nucleon hole-state at the bottom of the Fermi sea comes out as
$W(0,k_{f0})=29.7 $MeV. The basic theorems of Hugenholtz-Van-Hove and Luttinger
are satisfied in our perturbative two-loop calculation of the nuclear mean
field.


title: Squeezing lepton pairs out of broken symmetries

abstract:
  We discuss two possible signatures of symmetry breaking that can appear in
dilepton spectra, as measured in relativistic heavy ion collisions. The first
involves scalar-vector meson mixing and is related to the breaking of Lorentz
symmetry by a hot medium. The second is related to the breaking of Furry's
theorem by a charged quark-gluon plasma. Those signals will be accessible to
upcoming measurements to be performed at the GSI, RHIC, and the LHC.


title:
Bridging Two Ways of Describing Final-State Interactions in A(e,e'p)
  Reactions

abstract:
  We outline a relativistic and unfactorized framework to treat the final-state
interactions in quasi-elastic A(e,e'p) reactions for four-momentum transfers
Q$^{2} \gtrsim 0.3$ (GeV/c)$^{2}$. The model, which relies on the eikonal
approximation, can be used in combination with optical potentials, as well as
with the Glauber multiple-scattering method. We argue that such a model can
bridge the gap between a typical ``low'' and ``high-energy'' description of
final-state interactions, in a reasonably smooth fashion. This argument is made
on the basis of calculated structure functions, polarization observables and
nuclear transparencies for the target nuclei $^{12}$C and $^{16}$O.


title:
A Realistic Solvable Model for the Coulomb Dissociation of Neutron Halo
  Nuclei

abstract:
  As a model of a neutron halo nucleus we consider a neutron bound to an inert
core by a zero range force. We study the breakup of this simple nucleus in the
Coulomb field of a target nucleus. In the post-form DWBA (or, in our simple
model CWBA (``Coulomb Wave Born Approximation'')) an analytic solution for the
T-matrix is known. We study limiting cases of this T-matrix. As it should be,
we recover the Born approximation for weak Coulomb fields (i.e., for the
relevant Coulomb parameters much smaller than 1). For strong Coulomb fields,
high beam energies, and scattering to the forward region we find a result which
is very similar to the Born result. It is only modified by a relative phase
(close to 0) between the two terms and a prefactor (close to 1). A similar
situation exists for bremsstrahlung emission. This formula can be related to
the first order semiclassical treatment of the electromagnetic dissociation.
Since our CWBA model contains the electromagnetic interaction between the core
and the target nucleus to all orders, this means that higher order effects
(including postacceleration effects) are small in the case of high beam
energies and forward scattering. Our model also predicts a scaling behavior of
the differential cross section, that is, different systems (with different
binding energies, beam energies and scattering angles) show the same dependence
on two variables x and y.


title: Local Density Approximation for Systems with Pairing Correlations

abstract:
  I formulate a local density approximation for fermion systems with pairing
correlations based on a rapidly converging renormalization scheme for the
pairing gap.


title:
Effective field theory contribution to charge symmetry breaking NN
  scattering

abstract:
  The effect of isospin breaking pion s-wave rescattering is included in
elastic NN scattering at low energies using effective field theory. Although
this mechanism gave a large contribution to charge symmetry breaking in np -->
d pi0, the effect is rather small in pp vs. nn scattering parameters and in the
3H-3He binding energy difference. This smallness is caused by large
cancellation of the up-down quark mass difference contribution and
electromagnetic effects to the np mass difference.


title:
Consequences of a Relativistic Pseudospin Symmetry for Radial Nodes and
  Intruder Levels in Nuclei

abstract:
  The identification of pseudospin symmetry as a relativistic symmetry of the
Dirac Hamiltonian is used to explain the structure of radial nodes occurring in
pseudospin doublets and to illuminate the special status of nodeless intruder
states in nuclei.


title: Vector Mesons and Baryon Resonances in Nuclear Matter

abstract:
  We calculate the effect of many-body interactions in nuclear matter on the
spectral function of $\rho$ and $\omega$ meson. In particular, we focus on the
role played by baryon resonances in this context.


title: Photon and Electron induced Particle Production on Nuclei

abstract:
  We discuss several particle production reactions on nuclei within a BUU
transport model. After a short presentation of the model we show our results
for the transparency ratio for the nucleon knock-out reaction in different
nuclei. The influence of the nucleon spectral function on subthreshold particle
production is discussed.


title:
Isoscalar-Isovector Interferences in $\pi N \to N e^+ e^-$ Reactions as
  a Probe of Baryon Resonance Dynamics

abstract:
  The isoscalar-isovector ($\rho-\omega$) interferences in the exclusive
reactions $\pi^- p \to n e^+ e^-$ and $\pi^+ n \to p e^+ e^-$ near the $\omega$
threshold leads to a distinct difference of the dielectron invariant mass
distributions depending on beam energy. The strength of this effect is
determined by the coupling of resonances to the nucleon vector-meson channels
and other resonance properties. Therefore, a combined analysis of these
reactions can be used as a tool for determining the baryon resonance dynamics.


title: Photons from Nucleus-Nucleus Collisions at Ultra-Relativistic Energies

abstract:
  We compare the photon emission rates from hot hadronic matter with in-medium
mass shift and Quark Gluon Plasma (QGP). It is observed that the WA98 data can
be well reproduced by hadronic initial state with initial temperature $\sim
200$ MeV if the universal scaling of temperature dependent hadronic masses are
assumed and the evolution of temperature with time is taken from transport
model or (3+1) dimensional hydrodynamics. The data can also be reproduced by
QGP initial state with similar initial temperature and non-zero initial radial
velocity.


title:
Analytical E1 strength functions of two-neutron halo nuclei: the 6-He
  example

abstract:
  An analytical model is developed to study the spectra of electromagnetic
dissociation of two-neutron halo nuclei without precise knowledge about initial
and final states. Phenomenological three-cluster bound state wave functions,
reproducing the most relevant features of these nuclei, are used along with no
interaction final states. The 6-He nucleus is considered as a test case, and a
good agreement with experimental data concerning the shape of the spectrum and
the magnitude of the strength function is found.


title: Microscopic description of $\eta$-photoproduction on light nuclei

abstract:
  A microscopic four-body description of near-threshold coherent
photoproduction of the $\eta$ meson on the (3N)-nuclei is given. The
photoproduction cross-section is calculated using the Finite Rank Approximation
(FRA) of the nuclear Hamiltonian. The results indicate that the final state
interaction of the $\eta$ meson with the residual nucleus plays an important
role in the photoproduction process. Sensitivity of the results to the choice
of the $\eta N$ T-matrix is investigated. The importance of obeying the
condition of $\eta N$ unitarity is demonstrated.


title: Faddeev Approach to the Study of One- and Two-hole Spectral Functions

abstract:
  Theoretical calculations of one- and two-hole spectral functions for the O16
nucleus are still failing to describe some of the important features observed
experimentally. Of critical importance for the solution of these issues is to
obtain an appropriate description of the interplay between hole-hole and
particle-hole excitations. A formalism is reviewed here that allows the
consistent treatment of such phonons at a Random Phase approximation level.
Although the application of this formalism to O16 is still in the
implementation stage, some preliminary results are discussed here.


title:
A renormalisation-group approach to two-body scattering with long-range
  forces

abstract:
  We apply the renormalisation-group to two-body scattering by a combination of
known long-range and unknown short-range forces. A crucial feature is that the
low-energy effective theory is regulated by applying a cut-off in the basis of
distorted waves for the long range potential. We illustrate the method by
applying it to scattering in the presence of a repulsive 1/r^2 potential. We
find a trivial fixed point, describing systems with weak short-range
interactions, and a unstable fixed point. The expansion around the latter
corresponds to a distorted-wave effective-range expansion.


title:
Extended M1 sum rule for excited symmetric and mixed-symmetry states in
  nuclei

abstract:
  A generalized M1 sum rule for orbital magnetic dipole strength from excited
symmetric states to mixed-symmetry states is considered within the
proton-neutron interacting boson model of even-even nuclei. Analytic
expressions for the dominant terms in the B(M1) transition rates from the first
and second $2^+$ states are derived in the U(5) and SO(6) dynamic symmetry
limits of the model, and the applicability of a sum rule approach is examined
at and in-between these limits. Lastly, the sum rule is applied to the new data
on mixed-symmetry states of 94Mo and a quadrupole d-boson ratio
$nd(0^+_1)/nd(2^+_2) \approx 0.6$ is obtained in a largely
parameter-independent way


title: Singlet and Triplet Differential Cross Sections for pp-> pp pi^0

abstract:
  The singlet and triplet differential cross sections for pp-> pp pi^0 have
been estimated for the first time at 325, 350, 375 and 400 MeV using the
results of the recent experimental measurements [Phys. Rev. C 63, 064002
(2001)] of Meyer et al.


title: $\omega$-Meson Photoproduction on Nucleons In the Near Threshold Region

abstract:
  The $\omega$-meson photoproduction, $\gamma+p\to p+\omega$, is studied in the
framework of a model, containing $\pi$-meson exchange in t-channel and
nucleon-exchange in s- and u-channels. Considering both $\omega NN$-coupling
constants in the region of time-like meson four momenta as the free parameters,
we find different sets of solutions for these constants from the existing data
on the t-dependence of the differential cross sections, $d\sigma(\gamma+p\to
p+\omega)/dt$, in the near threshold region $E_{\gamma}\leq 2$ GeV. These sets
of $\omega NN$-coupling constants, corresponding to destructive and
constructive $\pi\bigotimes N$-interference contributions to $d\sigma/dt$ can
be well distinguished by measurements of beam asymmetry, induced by linear
photon polarization.


title: Relevance of high-momentum nucleons for nuclear phenomena

abstract:
  A brief review is given concerning the status of the theoretical work on
nucleon spectral functions. A recent concern about the validity of the concept
of spectroscopic factors as deduced from (e,e'p) reactions at higher Q^2, is
discussed in some detail. The consequences of the observed spectral strength
are then considered in the context of nuclear saturation. It is argued that
short-range correlations are mainly responsible for the actual value of the
observed charge density in 208Pb and by extension for the empirical value of
the saturation density of nuclear matter. This observation combined with the
general understanding of the spectroscopic strength suggests that a renewed
study of nuclear matter, emphasizing the self-consistent determination of the
spectral strength due to short-range and tensor correlations, may shed light on
the perennial nuclear saturation problem. First results using such a scheme are
presented.


title: Saturation properties of nuclear matter and correlated nucleons

abstract:
  A brief overview is given of the properties of spectral functions in finite
nuclei as obtained from (e,e'p) experiments. Based on recent experimental data
from this reaction it is argued that the empirical value of the saturation
density of nuclear matter is dominated by short-range correlations. This
observation and the observed fragmentation and depletion of the single-particle
strength in nuclei provide the motivation for attempting a self-consistent
description of the nucleon spectral functions with full inclusion of
short-range and tensor correlations in nuclear matter. Results for these
``second generation'' spectral functions will be discussed with emphasis on the
consequences for the saturation properties of nuclear matter. Arguments are
presented to clarify the obscuring role of pionic long-range correlations in
this long-standing problem.


title: Nuclear equation of state and spectral functions

abstract:
  An overview is given of the theoretical work on nucleon spectral functions in
finite nuclei. The consequences of the observed spectral strength distribution
are then considered in the context of the nuclear-matter saturation problem.
Arguments are presented suggesting that short-range correlations are mainly
responsible for the actual value of the observed charge density in 208Pb and by
extension for the empirical value of the saturation density of nuclear matter.
This observation combined with the general understanding of the spectroscopic
strength suggests that a renewed study of nuclear matter, emphasizing the
self-consistent determination of the spectral strength due to short-range and
tensor correlations, may shed light on the perennial nuclear saturation
problem. First results using such a scheme are presented. Arguments are
discussed that clarify the role of long-range correlations and their relevance
for nuclear saturation.


title: Coherent Photoproduction of eta-mesons on Three-Nucleon Systems

abstract:
  A microscopic few-body description of near-threshold coherent photoproduction
of the eta-meson on tritium and He3 targets is given. The photoproduction
cross-section is calculated using the Finite Rank Approximation (FRA) of the
nuclear Hamiltonian. The results indicate a strong final state interaction of
the eta-meson with the residual nucleus. Sensitivity of the results to the
choice of the eta-N T-matrix is investigated. The importance of obeying the
two-body unitarity condition in the eta-N system is demonstrated.


title: Pseudoscalar and vector meson production in NN collisions

abstract:
  Heavy meson production in nucleon-nucleon collisions is discussed within a
meson exchange model of hadronic interactions, paying special attention to the
basic dynamics that determine the behavior of the cross sections near the
threshold energy. The pp-->pp\phi reaction is discussed as an example of the
production of vector mesons in NN collisions. For the pseudoscalar meson
production, results for the \eta production in both the pp and pn collisions
are presented.


title: Hydrodynamical analysis of flow at RHIC

abstract:
  We use a hydrodynamical model to describe the evolution of the collision
system at collision energies sqrt{s}=130 and 200 GeV. At lower sqrt{s}=130 GeV
energy we compare the results obtained assuming fast or slow thermalization
(thermalization times tau_0=0.6 and 4.1 fm/c, respectively) and show that slow
thermalization fails to reproduce the observed anisotropy of particle
distribution. At sqrt{s}=200 GeV collision energy our results show anisotropies
similar to those observed at sqrt{s}=130 GeV.


title: Formation of Nuclear "Pasta" in Cold Neutron Star Matter

abstract:
  Formation and decay of rod-like and slab-like nuclei, as may be encountered
in the outer parts of neutron stars, are examined within a zero-temperature
stability analysis with respect to perturbations inducing fission and proton
clustering. The nonspherical nuclei are found to be stable against these
perturbations, implying the possibility that the size of the stellar region
containing such nuclei exceeds the equilibrium prediction.


title:
Vector meson masses in hot nuclear matter : the effect of quantum
  corrections

abstract:
  The medium modification of vector meson masses is studied taking into account
the quantum correction effects for the hot and dense hadronic matter. In the
framework of Quantum Hadrodynamics, the quantum corrections from the baryon and
scalar meson sectors were earlier computed using a nonperturbative variational
approach through a realignment of the ground state with baryon-antibaryon and
sigma meson condensates. The effect of such corrections was seen to lead to a
softer equation of state giving rise to a lower value for the compressibility
and, an increase in the in-medium baryonic masses than would be reached when
such quantum effects are not taken into account. These quantum corrections
arising from the scalar meson sector result in an increase in the masses of the
vector mesons in the hot and dense matter, as compared to the situation when
only the vacuum polarisation effects from the baryonic sector are taken into
account.


title: The neutron radii of Lead and neutron stars

abstract:
  A new relation between the neutron skin of a heavy nucleus and the radius of
a neutron star is proposed: the larger the neutron skin of the nucleus the
larger the radius of the star. Relativistic models that reproduce a variety of
ground-state observables can not determine uniquely the neutron skin of a heavy
nucleus. Thus, a large range of neutron skins is generated by supplementing the
models with nonlinear couplings between isoscalar and isovector mesons. We
illustrate how the correlation between the neutron skin and the radius of the
star can be used to place important constraints on the equation of state and
how it may help elucidate the existence of a phase transition in the interior
of the neutron star.


title: Relativistic effects in quasielastic electron scattering

abstract:
  The impact of pionic correlations and meson-exchange currents on the
quasi-elastic electromagnetic response functions is studied in a fully
relativistic framework.


title: Two-Pion Exchange in proton-proton Scattering

abstract:
  We present calculations of the two-pion-exchange contribution to
proton-proton scattering at 90 degrees using form factors appropriate for
representing the distribution of the constituent partons of the nucleon. Talk
given at MENU2001, George Washington University, July 26-31, 2001


title:
Partonic effects on the elliptic flow at relativistic heavy ion
  collisions

abstract:
  The elliptic flow in heavy ion collisions at RHIC is studied in a multiphase
transport model. By converting the strings in the high energy density regions
into partons, we find that the final elliptic flow is sensitive to the parton
scattering cross section. To reproduce the large elliptic flow observed in
Au+Au collisions at $\sqrt s=130A$ GeV requires a parton scattering cross
section of about 6 mb. We also study the dependence of the elliptic flow on the
particle multiplicity, transverse momentum, and particle mass.


title:
Low momentum nucleon-nucleon potential and shell model effective
  interactions

abstract:
  A low momentum nucleon-nucleon (NN) potential $V_{low-k}$ is derived from
meson exhange potentials by integrating out the model dependent high momentum
modes of $V_{NN}$. The smooth and approximately unique $V_{low-k}$ is used as
input for shell model calculations instead of the usual Brueckner $G$ matrix.
Such an approach eliminates the nuclear mass dependence of the input
interaction one finds in the $G$ matrix approach, allowing the same input
interaction to be used in different nuclear regions. Shell model calculations
of $^{18}$O and $^{134}$Te using the {\bf same} input $V_{low-k}$ have been
performed. For cut-off momentum $\Lambda$ in the vicinity of 2 $fm^{-1}$, our
calculated low-lying spectra for these nuclei are in good agreement with
experiments, and are weakly dependent on $\Lambda$.


title: Towards a Model-Independent Low Momentum Nucleon-Nucleon Interaction

abstract:
  We provide evidence for a high precision model-independent low momentum
nucleon-nucleon interaction. Performing a momentum-space renormalization group
decimation, we find that the effective interactions constructed from various
high precision nucleon-nucleon interaction models, such as the Paris, Bonn,
Nijmegen, Argonne, CD Bonn and Idaho potentials, are identical. This
model-independent low momentum interaction, called V_{low k}, reproduces the
same phase shifts and deuteron pole as the input potential models, without
ambiguous assumptions on the high momentum components, which are not
constrained by low energy data and lead to model-dependent results in many-body
applications. V_{low k} is energy-independent and does not necessitate the
calculation of the Brueckner G matrix.


title:
Matrix Elements of Twist-2 Operators in Quenched Chiral Perturbation
  Theory

abstract:
  We compute the leading non-analytic quark mass dependence of the matrix
elements of isovector twist-2 operators between octet baryon states in quenched
QCD using quenched chiral perturbation theory. There are contributions of the
form m_q log m_q, in analogy with QCD, but there are also contributions of the
form log m_q from hairpin interactions. The nucleon does not receive such
hairpin contributions.


title:
Centrality Dependence of Baryon and Meson Momentum Distributions in
  Proton-Nucleus Collisions

abstract:
  The proton and neutron inclusive distributions in the projectile
fragmentation region of $pA$ collisions are studied in the valon model.
Momentum degradation and flavor changes due to the nuclear medium are described
at the valon level using two parameters. Particle production is treated by
means of the recombination subprocess. The centrality dependences of the net
proton and neutron spectra of the NA49 data are satisfactorily reproduced. The
effective degradation length is determined to be 17 fm. Pion inclusive
distributions can be calculated without any adjustable parameters.


title:
Hadron structure and the limitations of phenomenological models in
  electromagnetic reactions

abstract:
  The description of electromagnetic reactions at intermediate energies, such
as pion electroproduction or (virtual) Compton scattering, traditionally starts
from covariant tree-level Feynman diagrams (Born or pole terms). Internal
hadron structure is included by means of (on-shell) form factors in the
vertices while free propagators are used. To overcome problems with gauge
invariance, simple prescriptions such as choosing $F_1^V (q^2) = F_{\pi} (q^2)$
in pion electroproduction or the ``minimal substitution'' are used. We discuss
the limitations of such approaches by comparing to the most general structure
of electromagnetic vertices and propagators for pions and nucleons. The recipes
to enforce gauge invariance are critically examined and contrasted with the
exact treatment. The interplay between off-shell effects and irreducible
``contact'' terms is demonstrated for real Compton scattering on a pion. The
need for a consistent microscopic treatment of reaction amplitudes is stressed.
Shortcomings of minimal substitution are illustrated through an example in the
framework of chiral perturbation theory.


title: On the nuclear dependence of the mu-e conversion branching ratio

abstract:
  The variation of the coherent branching ratio $R_{\mu e}$ (ratio of the
$\mu^-\to e^-$ reaction rate divided by the total muon-capture rate) through
the periodic table is studied by using exact muon wave functions. It was found
that, by using very heavy nuclei (e.g. \nuc{197}Au, the SINDRUM II target) as
$\mu^-\to e^-$ conversion stopping-targets, the above ratio is favored by a
factor of about four to five than by using light ones (e.g. \nuc{48}Ti, chosen
as PRIME target).


title: Pair Creation and an X-ray Free Electron Laser

abstract:
  Using a quantum kinetic equation coupled to Maxwell's equation we study the
possibility that focused beams at proposed X-ray free electron laser facilities
can generate electric field strengths large enough to cause spontaneous
electron-positron pair production from the QED vacuum. Our approach yields the
time and momentum dependence of the single particle distribution function.
Under conditions reckoned achievable at planned facilities, repeated cycles of
particle creation and annihilation take place in tune with the laser frequency.
However, the peak particle number density is insensitive to this frequency and
one can anticipate the production of a few hundred particle pairs per laser
period. Field-current feedback and quantum statistical effects are small and
can be neglected in this application of non-equilibrium quantum mean field
theory.


title:
Proton Differential Elliptic Flow and the Isospin-Dependence of the
  Nuclear Equation of State

abstract:
  Within an isospin-dependent transport model for nuclear reactions involving
neutron-rich nuclei, we study the first-order direct transverse flow of protons
and their second-order differential elliptic flow as a function of transverse
momentum. It is found that the differential elliptic flow of mid-rapidity
protons, especially at high transverse momenta, is much more sensitive to the
isospin dependence of the nuclear equation of state than the direct flow.
Origins of these different sensitivities and their implications to the
experimental determination of the isospin dependence of the nuclear equation of
state by using neutron-rich heavy-ion collisions at intermediate energies are
discussed.


title:
Generalized scaling of the transverse mass spectrum at the Relativistic
  Heavy-Ion Collider

abstract:
  We argue that the transverse mass spectra of identified hadrons as measured
in gold-gold collisions at BNL's Relativistic Heavy-Ion Collider (RHIC) follows
a generalized scaling law. Such a scaling behavior is motivated by the idea of
a Color Glass Condensate, or more generally, saturation of the gluon density.
In particular, we describe the shapes of transverse mass spectra as a function
of centrality. This scaling of the transverse mass spectrum is shown to be
consistent with previously observed scaling of multiplicity with centrality.


title: Dynamical Study of the d(e,e' pi+) reaction

abstract:
  The $d(e,e'\pi^+)$ reaction in the parallel kinematics has been investigated
using a dynamical model of pion electroproduction on the nucleon. A unitary
$\pi NN$ model has been used in order to examine the effects due to the final
two-nucleon interactions, pion rescattering from the second nucleon, and the
intermediate $NN$ and $N\Delta$ interactions. It has been found that these $\pi
NN$ mechanisms are small, but they can have significant contributions to the
$d(e,e'\pi^+)$ cross sections through their interference with the dominant
impulse term. For the longitudinal cross sections, the effects due to the
interference between the pion pole term and other production mechanisms are
also found to be very large. Our findings clearly indicate that these
interference effects must be accounted for in any attempt to determine from the
$d(e,e'\pi^+)$ data whether the pion form factor and/or $\pi NN$ vertex of the
pion pole term are modified in the nuclear medium.


title: The Solar pp and hep Processes in Effective Field Theory

abstract:
  The strategy of modern effective field theory is exploited to pin down
accurately the flux $S$ factors for the $pp$ and $hep$ processes in the Sun.
The technique used is to combine the high accuracy established in few-nucleon
systems of the "standard nuclear physics approach" (SNPA) and the systematic
power counting of chiral perturbation theory (ChPT) into a consistent effective
field theory framework. Using highly accurate wave functions obtained in the
SNPA and working to \nlo3 in the chiral counting for the current, we make
totally parameter-free and error-controlled predictions for the $pp$ and $hep$
processes in the Sun.


title:
Flow effects on the freeze-out phase-space density in heavy ion
  collisions

abstract:
  The strong longitudinal expansion of the reaction zone formed in relativistic
heavy-ion collisions is found to significantly reduce the spatially averaged
pion phase-space density, compared to naive estimates based on thermal
distributions. This has important implications for data interpretation and
leads to larger values for the extracted pion chemical potential at kinetic
freeze-out.


title:
Towards understanding the probability of $0^+$ ground states in
  even-even many-body systems

abstract:
  For single-$j$ shells with $j={7/2}, {9/2}$ and 11/2, we relate the large
probability of $I^+$ ground states to the largest (smallest) coefficients
$\alpha^J_{I(v \beta)} = <nv \beta I |$ $A^{J \dagger} \cdot A^J | n v\beta
I>$, where $n$ is the particle number, $v$ is the seniority, $\beta$ is an
additional quantum number, and $I$ is the angular momentum of the state.
Interesting regularities of the probabilities of $I^+$ ground states are
noticed and discussed for 4-particle systems. Several counter examples of the
$0^+$ ground state (0GS) predominance are noticed for the first time.


title: Construction of Consistent Meson Exchange Currents by Laplace Transform

abstract:
  We propose a new method for the construction of a consistent meson exchange
current in $r$-space for the spin-isospin dependent central and tensor part of
phenomenological nucleon-nucleon potentials by using a Laplace transformation,
which allows the representation by a finite number of Yukawa functions. This
method is applied to the Paris and the recent Argonne $V_{18}$ potentials.
Results are presented for electrodisintegration of the deuteron near threshold.


title: Randomly interacting bosons, mean-fields and L=0 ground states

abstract:
  Random interactions are used to investigate to what extent the low-lying
behavior of even-even nuclei depend on particular nucleon-nucleon interactions.
The surprising results that were obtained for the interacting boson model, i.e.
the dominance of ground states with L=0 and the occurrence of both vibrational
and rotational structure, are interpreted and explained in terms of a
mean-field analysis.


title:
$\rho/\omega$ properties from dilepton spectra in $p A$ reactions at 12
  GeV

abstract:
  The dilepton production from $pC$ and $pCu$ collisions at $T_{lab}=12$ GeV is
calculated using the semi-classical BUU transport model, that includes the
off-shell propagation of vector mesons nonperturbatively and calculates the
width of the vector mesons dynamically. It is found that the collisional
broadening of the vector meson width and dropping vector meson masses lead to a
small enhancement of the dilepton yield below the $\omega$ meson mass pole in
$p Cu$ collisions compared to $p C$, which is, however, not sufficient to
explain the enhanced production of dileptons as observed in the experiment by
the KEK-PS E325 collaboration. It is argued that such in-medium effects are
expected to be small due to kinematical reasons -- the dominant part of vector
mesons radiate dileptons and decay outside the nucleus due to the finite
formation time for $\rho$ and $\omega$ mesons, which is large by Lorentz
covariance since the produced vector mesons move with high velocity relative to
the target nucleus.


title: Rapidity dependence of large-p_t hadron production at RHIC

abstract:
  We study the dependence of parton energy loss (quenching) on rapidity in
ultra-relativistic nuclear collisions at RHIC. This can provides invaluable
information on the density of the medium, which should be more dilute going
away from mid-rapidity, thereby reducing the effect of quenching. We predict a
clear effect at moderate transverse momenta $\sim$ 3 GeV.


title: Accurate Nucleon-Nucleon Potential Based upon Chiral Perturbation Theory

abstract:
  We present an accurate nucleon-nucleon ($NN$) potential based upon chiral
effective Lagrangians. The model includes one- and two-pion exchange
contributions up to chiral order three. We show that a quantitative fit of the
$NN$ $D$-wave phase shifts requires contact terms (which represent the short
range force) of order four. Within this framework, the $NN$ phase shifts below
300 MeV lab. energy and the properties of the deuteron are reproduced with
high-precision. This chiral $NN$ potential represents a reliable starting point
for testing the chiral effective field theory approach in exact few-nucleon and
microscopic nuclear many-body calculations. An important implication of the
present work is that the chiral $2\pi$ exchange at order four is of crucial
interest for future chiral $NN$ potential development.


title:
Relativistic Thomas-Fermi description of Sm isotopes at finite
  temperature

abstract:
  The caloric curve (excitation energy per particle as a function of
temperature) for finite nuclei is calculated within the non-linear Walecka
model for different proton fractions and different parameterizations. The
results obtained are compared with published experimental data and other
theoretical results. Other properties related with the droplet formation as the
surface energy, neutron skin thickness and binding energy per nucleon are also
displayed as a function of temperature and their behaviours are discussed. It
is shown that the caloric curve is sensitive to the proton fraction and to the
Coulomb interaction. At T=0 the droplet properties do not depend on the
parameterization used. At finite temperature however, the sensitivity appears.


title: Quartet S-wave p-d scattering in EFT

abstract:
  We present a power counting to include Coulomb effects in the three-nucleon
system in a low-energy pionless effective field theory (EFT). With this power
counting, the quartet S-wave proton-deuteron elastic scattering amplitude is
calculated. The calculation includes next-to-leading order (NLO) Coulomb
effects and next-to-next-to-leading order (NNLO) strong interaction effects,
with an estimated theoretical error of about 7 %. The EFT results agree with
potential model calculations and phase shift analysis of experimental data
within the estimated errors.


title: An Introduction to Few Nucleon Systems in Effective Field Theory

abstract:
  Progress in the Effective Field Theory of two and three nucleon systems is
sketched, concentrating mainly on the low energy version in which pions are
integrated out as explicit degrees of freedom. Examples given are: the
extraction of nucleon polarisabilities from deuteron Compton scattering at very
low energies; the energy dependence of the nucleon polarisabilities; three body
forces and the triton; and $\mathrm{nd}$ partial waves at momenta below the
pion cut.


title: Can Recent Charge Fluctuations Be a Reliable signal for a QGP at RHIC?

abstract:
  The recent papers of Jeon and Koch [1] and Asakawa, Heinz, and Muller [2]
argue that the event by event fluctuations of the ratio of the positively
charged and negatively charged pions provide a distinct signal for a QGP at
RHIC/LHC due to differences in those from the QGP phase and the Hadron Gas
Phase.In this paper we point out that aside from the questionability of the
many assumptions in the treatment used,even following their approach there are
other effects not considered, e.g. color charge fluctuations, which could
significantly or even completely wash out the proposed signal.Therefore lack of
observation of these charge fluctuation signals cannot lead one to conclude
that a QGP is not formed at RHIC. A general discussion of experimental
requirements for observation of such signals(if they exist),annd how to
interpret them is included.


title: A meson exchange model for the YN interaction

abstract:
  We present a new model for the hyperon-nucleon (Lambda N, Sigma N)
interaction, derived within the meson exchange framework. The model
incorporates the standard one boson exchange contributions of the lowest
pseudoscalar and vector meson multiplets with coupling constants fixed by SU(6)
symmetry relations. In addition - as the main feature of the new model - the
exchange of two correlated pions or kaons, both in the scalar-isoscalar (sigma)
and vector-isovector (rho) channels, is included.


title:
Renormalization of equations governing nucleon dynamics and nonlocality
  in time of the NN interaction

abstract:
  We discuss the problem of renormalization of dynamical equations which arises
in an effective field theory description of nuclear forces. By using a toy
model of the separable NN potential leading to logarithmic singularities in the
Born series, we show that renormalization gives rise to nucleon dynamics which
is governed by a generalized dynamical equation with a nonlocal-in-time
interaction operator. We show that this dynamical equation can open new
possibilities for applying the EFT approach to the description of low-energy
nucleon dynamics.


title: ISI and FSI in NN-->NNX reactions

abstract:
  The present status of the theoretical description of Initial (ISI) and Final
State Interactions (FSI) in nucleon induced exclusive meson production
processes close to threshold is reviewed. Shortcomings are addressed and new
perspectives given.


title: Correlations and charge distributions of medium heavy nuclei

abstract:
  The effects of long- and short-range correlations on the charge distributions
of some medium and heavy nuclei are investigated. The long-range correlations
are treated within the Random Phase Approximation framework and the short-range
correlations with a model inspired to the Correlation Basis Function theory.
The two type of correlations produce effects of the same order of magnitude. A
comparison with the empirical charge distribution difference between 206Pb and
205Tl shows the need of including both correlations to obtain a good
description of the data.


title: Neutron electric form factor at large momentum transfer

abstract:
  Based on the recent, high precision data for elastic electron scattering from
protons and deuterons, at relatively large momentum transfer $Q^2$, we
determine the neutron electric form factor up to $Q^2=3.5$ GeV$^2$. The values
obtained from the data (in the framework of the nonrelativistic impulse
approximation) are larger than commonly assumed and are in good agreement with
the Gari-Kr\"umpelmann parametrization of the nucleon electromagnetic form
factors.