title:
Superfluid to normal phase transition and extreme regularity of
  superdeformed bands

abstract:
  We derive the exact semiclassical expression for the second inertial
parameter $\cal B$ for the superfluid and normal phases. Interpolation between
these limiting values shows that the function ${\cal B}(I)$ changes sign at the
spin $I_c$, which is critical for a rotational spectrum. The quantity $\cal B$
turns out to be a sensitive measure of the change in static pairing
correlations. The superfluid-to-normal transition reveals itself in the
specific variation of the ratio ${\cal B}/{\cal A}$ versus spin $I$ with the
plateau characteristic of the normal phase. We find this dependence to be
universal for normal deformed and superdeformed bands. The long plateau with a
small value ${\cal B}/{\cal A}\sim A^{-8/3}$ explains the extreme regularity of
superdeformed bands.


title:
Redundant Components in the 3 alpha Faddeev Equation Using 2 alpha RGM
  Kernel

abstract:
  The 3 alpha Faddeev equation using 2 alpha RGM kernel involves redundant
components whose contribution to the total wave function completely cancels
out. We propose a practical method to solve this Faddeev equation, by
eliminating the admixture of such redundant components. A complete equivalence
between the present Faddeev approach and a variational approach using the
translationally invariant harmonic-oscillator basis is numerically shown with
respect to the 3 alpha bound state corresponding to the ground state of 12C.


title: Proton Drip-Line Calculations and the Rp-process

abstract:
  One-proton and two-proton separation energies are calculated for proton-rich
nuclei in the region $ A=41-75 $. The method is based on Skyrme Hartree-Fock
calculations of Coulomb displacement energies of mirror nuclei in combination
with the experimental masses of the neutron-rich nuclei. The implications for
the proton drip line and the astrophysical rp-process are discussed. This is
done within the framework of a detailed analysis of the sensitivity of rp
process calculations in type I X-ray burst models on nuclear masses. We find
that the remaining mass uncertainties, in particular for some nuclei with
$N=Z$, still lead to large uncertainties in calculations of X-ray burst light
curves. Further experimental or theoretical improvements of nuclear mass data
are necessary before observed X-ray burst light curves can be used to obtain
quantitative constraints on ignition conditions and neutron star properties. We
identify a list of nuclei for which improved mass data would be most important.


title: The $\sigma$ meson in a nuclear medium through two pion photoproduction

abstract:
  We present theoretical results for $(\gamma, \pi^0 \pi^0)$ production on
nucleons and nuclei in the kinematical region where the scalar isoscalar $\pi
\pi$ amplitude is influenced by the $\sigma$ pole. The final state interaction
of the pions modified by the nuclear medium produces a spectacular shift of
strength of the two pion invariant mass distribution induced by the moving of
the $\sigma$ pole to lower masses and widths as the nuclear density increases.


title: Dynamical Effects beyond Mean Field in Drip Line Nuclei

abstract:
  New structure problems are raised in nuclei near drip lines by recent RIB
experiments. We pointed out the importance of dynamical effect beyond mean
field theories to the new structure problems.


title:
Proton-neutron quadrupole interactions: an effective contribution to the
  pairing field

abstract:
  We point out that the proton-neutron energy contribution, for low multipoles
(in particular for the quadrupole component), effectively renormalizes the
strength of the pairing interaction acting amongst identical nucleons filling
up a single-j or a set of degenerate many-j shells. We carry out the
calculation in lowest-order perturbation theory. We perform a study of this
correction in various mass regions. These results may have implications for the
use of pairing theory in medium-heavy nuclei and for the study of pairing
energy corrections to the liquid drop model when studying nuclear masses.


title:
Analytical E1 strength functions of two-neutron halo nuclei: 11-Li and
  14-Be

abstract:
  An analytical model, recently developed to study the electromagnetic
dissociation (EMD) energy spectra of two-neutron halo nuclei, is applied to
11-Li and 14-Be. We find that a reliable set of experimental data on EMD could
help to resolve the problem concerning the structure of the 11-Li ground state.
For 14-Be we find a mutual inconsistency between the existing experimental data
on the binding energy, radius and EMD energy spectrum. We also conclude that
the structure of 14-Be is essentially more complicated than the structure of
other Borromean two--neutron halo nuclei.


title:
Effects of T=0 two body matrix elements on M1 and Gamow-Teller
  transitions: isospin decomposition

abstract:
  We perform calculations for M1 transitions and allowed Gamow Teller (GT)
transitions in the even-even Titanium isotopes - $^{44}$Ti, $^{46}$Ti, and
$^{48}$Ti. We first do calculations with the FPD6 interaction. Then to study
the effect of T=0 matrix elements on the M1 and GT rates we introduce a second
interaction in which all the T=0 matrix elements are set equal to zero and a
third in which all the T=0 matrix elements are set to a constant. For the
latter two interactions the T=1 matrix elements are the same as for FPD6. We
are thus able to study the effects of the fluctuating T=0 matrix elements on M1
and GT rates.


title: Hadronic physics in peripheral heavy ion collisions

abstract:
  We discuss the production of hadronic resonances in very peripheral heavy ion
collisions, where the ions collide with impact parameter larger than twice the
nuclear radius and remain intact after the collision. We compare the resonance
production through two-photon and double Pomeron exchange, showing that when we
impose the condition for a peripheral interaction the $\gamma \gamma$ process
dominates over the Pomeron interaction, due to the short range propagation of
this last one. We also discuss the observation of light resonances through the
subprocess $\gamma \gamma \to R \to \gamma \gamma $, which is a clean signal
for glueball candidates as well as one way to check the existence of a possible
scalar $\sigma$ meson.


title: Relativistic Heavy Ion Excitation of Giant Resonances

abstract:
  Giant resonances and giant resonances built on other giant resonances in
nuclei are observed with very large cross sections in relativistic heavy ion
collisions. A theoretical effort is underway to understand the reaction
mechanism which leads to this process, as well as a better understanding of the
microscopic properties of multiphonon states, e.g., their strength, energy
centroids, widths and anharmonicities.


title:
Boson-conserving one-nucleon transfer operator in the interacting boson
  model

abstract:
  The boson-conserving one-nucleon transfer operator in the interacting boson
model (IBA) is reanalyzed. Extra terms are added to the usual form used for
that operator. These new terms change generalized seniority by one unit, as the
ones considered up to now. The results obtained using the new form for the
transfer operator are compared with those obtained with the traditional form in
a simple case involving the pseudo-spin Bose-Fermi symmetry $U^{B}(6) \otimes
U^F(12)$ in its $U^{BF}(5) \otimes U^F(2)$ limit. Sizeable differences are
found. These results are of relevance in the study of transfer reactions to
check nuclear supersymmetry and in the description of (\beta)-decay within IBA.


title: Neutrino-deuteron reactions at solar neutrino energies

abstract:
  In interpreting the SNO experiments, very accurate estimates of the \nu d
reaction cross sections are of great importance. We improve the previous
estimates of our group by updating some of its inputs and by taking into
account the results of a recent effective-field-theoretical calculation. The
new cross sections are slightly (\sim 1%) larger than the previously reported
values. We present arguments that lead to the conclusion that it is reasonable
to assign 1% uncertainty to the \nu d cross sections reported here.


title:
Strange baryons in a hot and dense medium within the Nambu-Jona-Lasinio
  model

abstract:
  Using an extended version of the Nambu-Jona-Lasinio model we build a simple
description of the baryons as diquark-quark bound states. First, a description
of the diquarks in a dense and hot medium is presented.
  Then, we introduce the formalism for the baryons based on the Faddeev
equation associated with the so-called `` static approximation'' which finally
gives a Bethe-Salpeter equation in the diquarks-quarks channel. By identifying
the baryons with the bound states, we can obtain a description of their
properties. In particular, we obtain the right mass spectrum for the proton,
$\Lambda$, $\Xi$, and $\Sigma$ at T=0 and $\mu=0$. We extend the formalism to
finite temperature and density to obtain a description of the mass change of
these baryons in the medium.


title:
Few-Nucleon Systems with Two-Nucleon Forces from Chiral Effective Field
  Theory

abstract:
  Nucleon-nucleon (NN) forces from chiral perturbation theory at
next-to-leading (NLO) and next-to-next-to-leading order (NNLO) are applied to
systems with two, three and four nucleons. At NNLO, we consider two versions of
the chiral potential which differ in the strength of the two-pion-exchange
(TPE) but describe two nucleon observables equally well. The NNLO potential
leads to unphysical deeply bound states in the low partial waves and effects of
the 3N forces, which appear first at this order, are expected to be large. We
provide arguments for a reduction of the TPE potential and introduce the NNLO*
version of the NN forces. We calculate nd scattering observables as well as
various properties of 3H and 4He with the NNLO* potential and find good
agreement with the data and with predictions based upon the standard
high-precision potentials. We find an improved description of the 3H and 4He
binding energies.


title:
On the Fermi and Gamow-Teller strength distribution in medium-heavy mass
  nuclei

abstract:
  An isospin-selfconsistent approach based on the
Continuum-Random-Phase-Approximation (CRPA) is applied to describe the Fermi
and Gamow-Teller strength distributions within a wide excitation-energy
interval. To take into account nucleon pairing in open-shell nuclei, we
formulate an isospin-selfconsistent version of the
proton-neutron-quasiparticle-CRPA (pn-QCRPA) approach by incorporating the BCS
model into the CRPA method. The isospin and configurational splittings of the
Gamow-Teller giant resonance are analyzed in single-open-shell nuclei. The
calculation results obtained for $^{208}$Bi, $^{90}$Nb, and Sb isotopes are
compared with available experimental data.


title: Study of Spectral Modification of Hadrons through Electromagnetic Probes

abstract:
  The medium modification of vector meson properties and its effects on thermal
photon and dilepton emission rates from hot/dense hadronic matter are
discussed. The role of spectral changes of hadrons in explaining the WA98
photon data and the CERES/NA45 dilepton data with similar initial conditions is
demonstrated.


title: Oscillations in finite Fermi systems

abstract:
  A semiclassical linear response theory based on the Vlasov equation is
reviewed. The approach discussed here differs from the classical one of Vlasov
and Landau for the fact that the finite size of the system is explicitly taken
into account. The non-trivial problem of deciding which boundary conditions are
more appropriate for the fluctuations of the phase-space density has been
circumvented by studying solutions corresponding to different boundary
conditions (fixed and moving surface). The fixed-surface theory has been
applied to systems having both spherical and spheroidal equilibrium shapes. The
moving-surface theory is related to the liquid-drop model of the nucleus and
from it one can obtain a kinetic-theory description of surface and compression
modes in nuclei. Quantum corrections to the semiclassical theory are also
briefly discussed.


title:
Angle-dependent normalization of neutron-proton differential cross
  sections

abstract:
  Systematic errors in the database of $np$ differential cross sections below
350 MeV are studied. By applying angle-dependent normalizations with the help
of the energy-dependent Nijmegen partial-wave analysis PWA93 the
$\chi^2$-values of some seriously flawed data sets can be reduced significantly
at the expense of a few degrees of freedom. It turns out that in these special
cases the renormalized data sets can be made statistically acceptable such that
they do not have to be discarded any longer in partial-wave analyses of the
two-nucleon scattering data.


title:
K$^+$ production in proton-nucleus reactions and the role of
  momentum-dependent potentials

abstract:
  The production of $K^+$ mesons in proton-nucleus collisions from 1.0 to 2.5
GeV is analyzed with respect to one-step nucleon-nucleon $(NN\to N Y K^+$) and
two-step $\Delta$-nucleon $(\Delta N \to K^+ Y N$) or pion-nucleon $(\pi N \to
K^+ Y $) production channels on the basis of a coupled-channel transport
approach (CBUU) including the kaon final state interactions. The influence of
momentum-dependent potentials for the nucleon, hyperon and kaon in the final
state are studied as well as the importance of $K^+$ elastic rescattering in
the target nucleus. The transport calculations are compared to the experimental
$K^+$ spectra taken at LBL Berkeley, SATURNE, CELSIUS, GSI and COSY-J\"ulich.
It is found that the momentum-dependent baryon potentials effect the excitation
function of the $K^+$ cross section; at low bombarding energies of $\sim $ 1.0
GeV the attractive baryon potentials in the final state lead to a relative
enhancement of the kaon yield whereas the net repulsive potential at bombarding
energies $\sim$ 2 GeV causes a decrease of the $K^+$ cross section. Furthermore
it is pointed out, that especially the $K^+$ spectra at low momenta (or kinetic
energy $T_K$) allow to determine the in-medium $K^+$ potential almost model
independently due to a relative shift of the $K^+$ spectra in kinetic energy
that arises from the acceleration of the kaons when propagating out of the
nuclear medium to free space, i.e. converting potential energy to kinetic
energy of the free kaon.


title: Mechanical and chemical spinodal instabilities in finite quantum systems

abstract:
  Self consistent quantum approaches are used to study the instabilities of
finite nuclear systems. The frequencies of multipole density fluctuations are
determined as a function of dilution and temperature, for several isotopes. The
spinodal region of the phase diagrams is determined and it appears that
instabilities are reduced by finite size effects. The role of surface and
volume instabilities is discussed. It is indicated that the important chemical
effects associated with mechanical disruption may lead to isospin
fractionation.


title:
Finite temperature and chemical potential in lattice QCD and its
  critical point

abstract:
  We propose a method to study lattice QCD at finite temperature (T) and
chemical potential (\mu). We compare the method with direct results and with
the Glasgow method by using n_f=4 QCD at Im(\mu)\neq0. We locate the critical
endpoint (E) of QCD on the Re(\mu)-T plane. We use n_f=2+1 dynamical staggered
quarks with semi-realistic masses on L_t=4 lattices. Our results are based on
{\cal{O}}(10^3-10^4) configurations.


title:
Study of Postacceleration Effects in the Coulomb Dissociation of Neutron
  Halo Nuclei

abstract:
  We investgate the breakup of one-neutron halo nuclei in the Coulomb field of
a target nucleus. In the post-form distorted wave Born approximation theory of
this reaction, with only Coulomb distortions in the entrance and the outgoing
channels, an analytic solution for the breakup $T$-matrix is known. We study
this $T$-matrix and the corresponding cross-sections numerically. This formula
can be related to the first order semiclassical treatment of the
electromagnetic dissociation. This theory contains the electromagnetic
interaction between the core and the target nucleus to all orders. We show that
higher order effects (including postacceleration) are small in the case of
higher beam energies and forward scattering. We investigate the beam energy
dependence of the postacceleration effects. They are found to be quite
important for smaller beam energies (slow collisions), but almost negligible at
larger ones.


title: Gamow Shell Model Description of Neutron-Rich Nuclei

abstract:
  This work presents the first continuum shell-model study of weakly bound
neutron-rich nuclei involving multiconfiguration mixing. For the
single-particle basis, the complex-energy Berggren ensemble representing the
bound single-particle states, narrow resonances, and the non-resonant continuum
background is taken. Our shell-model Hamiltonian consists of a one-body finite
potential and a zero-range residual two-body interaction. The systems with two
valence neutrons are considered. The Gamow shell model, which is a
straightforward extension of the traditional shell model, is shown to be an
excellent tool for the microscopic description of weakly bound systems. It is
demonstrated that the residual interaction coupling to the particle continuum
is important; in some cases, it can give rise to the binding of a nucleus.


title: Charm meson production from meson-nucleon scattering

abstract:
  Using an effective hadronic Lagrangian with physical hadron masses and
coupling constants determined either empirically or from SU(4) flavor symmetry,
we study the production cross sections of charm mesons from pion and rho meson
interactions with nucleons. With a cutoff parameter of 1 GeV at interaction
vertices as usually used in studying the cross sections for $J/\psi$ absorption
and charm meson scattering by hadrons, we find that the cross sections for
charm meson production have values of a few tenth of mb and are dominated by
the s channel nucleon pole diagram. Relevance of these reactions to charm meson
production in relativistic heavy ion collisions is discussed.


title: 9Be: A gateway nucleus into heavier nuclei?

abstract:
  Level structure of 9Be is investigated calculating poles of the alpha alphar
n three-body scattering amplitude in the complex energy plane. We find 10
levels, which make rotational bands in both positive and negative parities. All
of them, except 7/2^+, have been observed experimentally and the corresponding
positions and widths reasonably well matched. The 7/2^+ has a large width, and
therefore has not been found, but may cause a noise in the experiment. No other
levels are needed to explain the existing experimental observables below 11.28
MeV, where the 9th excited state exists. We definitely assign it 9/2^-.


title: Weak Transitions in A=6 and 7 Nuclei

abstract:
  The $^6$He beta decay and $^7$Be electron capture processes are studied using
variational Monte Carlo wave functions, derived from a realistic Hamiltonian
consisting of the Argonne $v_{18}$ two-nucleon and Urbana-IX three-nucleon
interactions. The model for the nuclear weak axial current includes one- and
two-body operators with the strength of the leading two-body term--associated
with $\Delta$-isobar excitation of the nucleon--adjusted to reproduce the
Gamow-Teller matrix element in tritium $\beta$-decay. The measured half-life of
$^6$. He is under-predicted by theory by $\simeq$ 8%, while that of $^7$Be for
decay into the ground and first excited states of $^7$Li is over-predicted by
$\simeq$ 9%. However, the experimentally known branching ratio for these latter
processes is in good agreement with the calculated value. Two-body axial
current contributions lead to a $\simeq$ 1.7% (4.4%) increase in the value of
the Gamow-Teller matrix element of $^6$He ($^7$Be), obtained with one-body
currents only, and slightly worsen (appreciably improve) the agreement between
the calculated and measured half-life. Corrections due to retardation effects
associated with the finite lepton momentum transfers involved in the decays, as
well as contributions of suppressed transitions induced by the weak vector
charge and axial current operators, have also been calculated and found to be
negligible.


title: Two-Particle Resonant States in a Many-Body Mean Field

abstract:
  A formalism to evaluate the resonant states produced by two particles moving
outside a closed shell core is presented. The two particle states are
calculated by using a single particle representation consisting of bound
states, Gamow resonances and scattering states in the complex energy plane
(Berggren representation). Two representative cases are analysed corresponding
to whether the Fermi level is below or above the continuum threshold. It is
found that long lived two-body states (including bound states) are mostly
determined by either bound single-particle states or by narrow Gamow
resonances. However, they can be significantly affected by the continuum part
of the spectrum.


title: Reaction Operator Approach to Multiple Elastic Scatterings

abstract:
  We apply the GLV Reaction Operator formalism to compute the effects of
multiple elastic scatterings of jets propagating through dense matter. We
derive the elastic Reaction Operator and demonstrate that the recursion
relations have a closed form solution that reduces to the familiar Glauber
form. We also investigate the accuracy of the Gaussian dipole approximation for
jet transverse momentum broadening.


title:
An Improved Quantum Molecular Dynamics Model and its Applications to
  Fusion Reaction near Barrier

abstract:
  An improved Quantum Molecular Dynamics model is proposed. By using this
model, the properties of ground state of nuclei from $^{6}$Li to $^{208}$Pb can
be described very well with one set of parameters. The fusion reactions for
$^{40}$Ca+$^{90}$Zr, $^{40}$Ca+$^{96}$Zr and $^{48}$Ca+$^{90}$Zr at energy near
barrier are studied by this model. The experimental data of the fusion cross
sections for $^{40}$Ca+$^{90,96}$Zr at the energy near barrier can be
reproduced remarkably well without introducing any new parameters. The
mechanism for the enhancement of fusion probability for fusion reactions with
neutron-rich projectile or target is analyzed.


title: Regular spectra in the vibron model with random interactions

abstract:
  The phenomenom of emerging regular spectral features from random interactions
is addressed in the context of the vibron model. A mean-field analysis links
different regions of the parameter space with definite geometric shapes. The
results that are, to a large extent, obtained in closed analytic form, provide
a clear and transparent interpretation of the high degree of order that has
been observed in numerical studies.


title: Mirror displacement energies and neutron skins

abstract:
  A gross estimate of the neutron skin [0.80(5)$(N-Z)/A$ fm] is extracted from
experimental proton radii, represented by a four parameter fit, and observed
mirror displacement energies (CDE). The calculation of the latter relies on an
accurately derived Coulomb energy and smooth averages of the charge symmetry
breaking potentials constrained to state of the art values. The only free
parameter is the neutron skin itself. The Nolen Schiffer anomaly is reduced to
small deviations (rms=127 keV) that exhibit a secular trend. It is argued that
with state of the art shell model calculations the anomaly should disappear.
Highly accurate fits to proton radii emerge as a fringe benefit.


title:
Axial vector diquark correlations in the nucleon: Structure functions
  and static properties

abstract:
  In order to extract information on the strength of quark-quark correlations
in the axial vector (a.v.) diquark channel ($J^P=1^+, T=1$), we analyze the
quark light cone momentum distributions in the nucleon, in particular their
flavor dependencies, and the static properties of the nucleon. To construct the
nucleon as a relativistic 3-quark bound state, we use a simple 'static'
approximation to the full Faddeev equation in the Nambu-Jona-Lasinio model,
including correlations in the scalar ($J^P=0^+, T=0$) and a.v. diquark
channels. It is shown that the a.v. diquark correlations should be rather weak
compared to the scalar ones. From our analysis we extract information on the
strength of the correlations as well as on the probability of the a.v. diquark
channel.


title: Effective Field Theory for Bulk Properties of Nuclei

abstract:
  Recent progress in Lorentz-covariant quantum field theories of the nuclear
many-body problem ({\em quantum hadrodynamics}, or QHD) is discussed. The
importance of modern perspectives in effective field theory and density
functional theory for understanding the successes of QHD is emphasized. The
inclusion of hadronic electromagnetic structure and of nonanalytic terms in the
energy functional is also considered.


title: Nucleon mass and pion loops

abstract:
  Poincare' covariant Faddeev equations for the nucleon and Delta are solved to
illustrate that an internally consistent description in terms of confined-quark
and nonpointlike confined-diquark-correlations can be obtained. pi N-loop
induced self-energy corrections to the nucleon's mass are analysed and shown to
be independent of whether a pseudoscalar or pseudovector coupling is used.
Phenomenological constraints suggest that this self-energy correction reduces
the nucleon's mass by up to several hundred MeV. That effect does not
qualitatively alter the picture, suggested by the Faddeev equation, that
baryons are quark-diquark composites. However, neglecting the pi-loops leads to
a quantitative overestimate of the nucleon's axial-vector diquark component.


title: Liquid Drop Model with Different Neutron versus Proton Deformations

abstract:
  The nuclear binding energies for 28 nuclei including several isotopic chains
with masses ranging from A=64 to A=226 were evaluated using the Skyrme
effective nucleon-nucleon interaction and the Extended Thomas-Fermi
approximation. The neutron and proton density distributions are assumed in the
form of Fermi functions the parameters of which are determined so as to
minimize the total binding energy of any given nucleus. The present study is
restricted to quadrupole shapes, but the neutron and proton density
distributions are free to have different deformations. A simple expression for
the variation of the nuclear energy with the neutron--proton deformation
difference is derived.


title: One-body Properties of Nuclear Matter with Off-shell Propagation

abstract:
  Symmetric nuclear matter is studied in the self-consistent, in-medium
$T$-matrix approach. One-body spectral function, optical potential, and
scattering width are calculated. Properties of quasi-particle excitations at
the Fermi surface are discussed. Dispersive self-energies are dominated by
contributions from the $^1S_0$, $3S_1-^3D_1$, and $^3P_1$ partial waves.


title: Nuclear magnetic dipole properties and the triaxial deformation

abstract:
  Nuclear magnetic dipole properties of ground bands and gamma-vibrational
bands are studied for the first time using the triaxial projected shell model
approach. The study is carried out for the Dy and Er isotopic chains, ranging
from transitional to well-deformed region. It is found that the g-factor ratio
of the 2^+ state in ground bands to that of gamma-bands, r=g(2^+,
gamma-vib)/g(2^+, ground), varies along an isotopic chain. With the
gamma-deformations, which best reproduce the energy levels for both bands, we
obtain a qualitative agreement with the experimental data. This result thus
suggests that study of the ratio may provide an important information on the
triaxial deformation of a nuclear system. The angular-momentum dependence of
the ground band g-factor on the triaxial deformation is also investigated.


title:
The nuclear equation of state probed by K+ production in heavy ion
  collisions

abstract:
  The dependence of K+ production on the nuclear equation of state is
investigated in heavy ion collisions. An increase of the excitation function of
K+ multiplicities obtained in heavy (Au+Au) over light (C+C) systems when going
far below threshold which has been observed by the KaoS Collaboration strongly
favours a soft equation of state. This observation holds despite of the
influence of an in-medium kaon potential predicted by effective chiral models
which is necessary to reproduce the experimental K+ yields. Phase space effects
are discussed with respect to the K+ excitation function.


title: On the Multiboson Coherent State in Deformed Boson Scheme

abstract:
  The treatment for the multiboson coherent state is extended for the
completeness of the formulation. The basic idea for the extension is presented
in terms of expanding the boson space. The MYT boson mapping plays a central
role. The resultant multiboson coherent state includes the state obtained in
our previous treatment and the form suggests various multiboson coherent states
are possible in the deformed boson scheme.


title: Two Contrastive Boson-Pair Coherent States in Deformed Boson Scheme

abstract:
  Two types of boson-pair coherent states, which were proposed independently by
the present authors, are investigated. Main conclusion is as follows : Although
the two states are superposed contrastively in terms of the boson-pairs, the
expectation values of the boson-pair operators for these states are the same as
one another with high accuracy.


title: Atomic spectra in a helium bubble

abstract:
  Density functional theory (DFT) is applied to atomic spectra under
perturbations of superfluid liquid helium. The atomic DFT of helium is used to
obtain the distribution of helium atoms around the impurity atom, and the
electronic DFT is applied to the excitations of the atom, averaging over the
ensemble of helium configurations. The shift and broadening of the D1 and D2
absorption lines are quite well reproduced by theory, suggesting that the DFT
may be useful for describing spectral perturbations in more complex
environments.


title:
Absorbing Boundary Condition Approach for Breakup Reactions of Halo
  Nuclei

abstract:
  Application of the absorbing boundary condition is discussed to analyse
breakup reactions of weakly bound nuclei. The key ingredient is an introduction
of the absorbing potential outside the physical area which simulates the
outgoing boundary condition approximately. The scattering problem is then
recasted into the Schroedinger like equation with a source term in the
interaction region and with the vanishing boundary condition at the boundary.
We demonstrate usefulness of the method taking a few examples. Deuteron breakup
reactions are examined comparing present results with those by the
continuum-discretized coupled-channel method. We next discuss the breakup
reactions of single-neutron halo nucleus, 11Be.


title: Chiral dynamics of nuclear matter at finite temperature

abstract:
  We extend a recent three-loop calculation of nuclear matter in the systematic
framework of chiral perturbation theory to finite temperatures T. The
contributions from one- and two-pion exchange diagrams which cause nuclear
binding and saturation at T=0 are included for T>0 in the density and
temperature dependent free energy per particle, $\bar F(rho,T)$. The so-called
anomalous 2pi-exchange contribution $\bar A(rho,T)$ (with no counterpart in the
ground state energy density at T=0) is consistently included. The calculated
pressure isotherms display the familiar first-order liquid-gas phase transition
of isospin symmetric nuclear matter with a critical point at T_c = 25.5 MeV and
rho_c = 0.09 fm^{-3}. The too high value of the critical temperature originates
from the strong momentum dependence of the underlying single-particle potential
U(p,k_{f0}) near the Fermi-surface. We also consider pure neutron matter at T>0
in the same framework and find fair agreement with sophisticated many-body
calculations for neutron densities rho_n < 0.2 fm^{-3}.


title: On "the authentic damping mechanism" of the phonon damping model

abstract:
  Some general features of the phonon damping model are presented. It is
concluded that the fits performed within this model have no physical content.


title: Search for new baryon resonances

abstract:
  Within a chiral constituent quark formalism, allowing the inclusion of all
known resonances, a comprehensive study of the recent eta photoproduction data
on the proton up to 2 GeV is performed. This study shows evidence for a new S11
resonances and indicates the presence of an additional missing P13 resonance.


title: Off-shell pions in Boltzmann-Uehling-Uhlenbeck transport theory

abstract:
  Due to large pi N --> Delta cross section a pion acquires a large width in
nuclear matter. Therefore, a Delta-resonance decaying in the nuclear medium can
produce far off-shell pions, which will gradually lose their virtuality while
propagating to the vacuum. To describe such off-shell dynamics, we implemented
a pion spectral function for finite nuclear matter density -- calculated on the
basis of the Delta-hole model -- in the BUU transport approach. The pion
off-shell dynamics leads to an enhancement of the low-p_t pion yields in the
collisions of Au+Au at 1 A GeV.


title:
Lorentz Integral Transform for Inclusive and Exclusive Cross Sections
  with the Lanczos Method

abstract:
  The Lorentz Integral Transform (LIT) method is reformulated via the Lanczos
algorithm both for inclusive and exclusive reactions. The new technique is
tested for the total photoabsorption cross section of 3H and 4He. Due to the
rapid convergence of the algorithm one has a decrease in cpu time by two orders
of magnitude, but at the same time an excellent agreement with the results of a
conventional LIT calculation. The present work opens up the possibility of ab
initio calculations for inclusive and exclusive processes for A greater equal 6
with inclusion of complete final state interactions.


title: QGP Theory: Status and Perspectives

abstract:
  The current status of Quark-Gluon-Plasma Theory is reviewed. Special emphasis
is placed on QGP signatures, the interpretation of current data and what to
expect from RHIC in the near future.


title: Formation time of hadrons in photon induced reactions on nuclei

abstract:
  We present a way to account for coherence length effects in a semi-classical
transport model. This allows us to describe photo- and electroproduction at
large nuclei (A>12) and high energies using a realistic coupled channel
description of the final state interactions that goes far beyond simple Glauber
theory. We show that the purely absorptive treatment of the final state
interactions as usually done in simple Glauber theory might lead to wrong
estimates of color transparency and formation time effects in particle
production. As an example we discuss exclusive rho^0 photoproduction on Pb at a
photon energy of 7 GeV as well as K^+ and K^- production on C and Pb in the
photon energy range 1-7 GeV.


title: Eta Meson Production in NN Collisions

abstract:
  Eta meson production in both proton-proton and proton-neutron collisions is
investigated within a relativistic meson exchange model of hadronic
interactions. It is found that the available cross section data can be
described equally well by either the vector or pseudoscalar meson exchange
mechanism for exciting the S_{11}(1535) resonance. It is shown that the
analyzing power data can potentially be very useful in distinguishing these two
scenarios for the excitaion of the S_{11}(1535) resonance.


title: Effects of momentum conservation on the analysis of anisotropic flow

abstract:
  We present a general method for taking into account correlations due to
momentum conservation in the analysis of anisotropic flow, either by using the
two-particle correlation method or the standard flow vector method. In the
latter, the correlation between the particle and the flow vector is either
corrected through a redefinition (shift) of the flow vector, or subtracted
explicitly from the observed flow coefficient. In addition, momentum
conservation contributes to the reaction plane resolution. Momentum
conservation mostly affects the first harmonic in azimuthal distributions,
i.e., directed flow. It also modifies higher harmonics, for instance elliptic
flow, when they are measured with respect to a first harmonic event plane such
as one determined with the standard transverse momentum method. Our method is
illustrated by application to NA49 data on pion directed flow.


title: Benchmark Calculation of the Three-Nucleon Photodisintegration

abstract:
  A benchmark is set on the three-nucleon photodisintegration calculating the
total cross section with modern realistic two- and three-nucleon forces (AV18,
UrbIX) using both the Faddeev equations and the Lorentz Integral Transform
method. This test shows that the precision of three-body calculations involving
continuum states is considerably higher than experimental uncertainties.
Effects due to retardations, higher multipoles, meson exchange currents and
Coulomb force are studied.


title: Toward a global description of the nucleus-nucleus interaction

abstract:
  Extensive systematization of theoretical and experimental nuclear densities
and of optical potential strengths exctracted from heavy-ion elastic scattering
data analyses at low and intermediate energies are presented.The
energy-dependence of the nuclear potential is accounted for within a model
based on the nonlocal nature of the interaction.The systematics indicate that
the heavy-ion nuclear potential can be described in a simple global way through
a double-folding shape,which basically depends only on the density of nucleons
of the partners in the collision.The poissibility of extracting information
about the nucleon-nucleon interaction from the heavy-ion potential is
investigated.


title: Return of the EMC Effect: Finite Nuclei

abstract:
  A light front formalism for deep inelastic lepton scattering from finite
nuclei is developed. In particular, the nucleon plus momentum distribution and
a finite system analog of the Hugenholtz-van Hove theorem are presented. Using
a relativistic mean field model, numerical results for the plus momentum
distribution and ratio of bound to free nucleon structure functions for Oxygen,
Calcium and Lead are given. We show that we can incorporate light front physics
with excellent accuracy while using easily computed equal time wavefunctions.
Assuming nucleon structure is not modified in-medium we find that the
calculations are not consistent with the binding effect apparent in the data
not only in the magnitude of the effect, but in the dependence on the number of
nucleons.


title: The extent of strangeness in equilibration in quark-gluon plasma

abstract:
  The evolution and production of strangeness from chemically equilibrating and
transversely expanding quark gluon plasma which may be formed in the wake of
relativistic heavy ion collisions is studied with initial conditions obtained
from the Self Screened Parton Cascade (SSPC) model. The extent of partonic
equilibration increases almost linearly with the square of the initial energy
density, which can then be scaled with number of participants.


title:
Azimuthal asymmetry of J/Psi suppression in non-central heavy-ion
  collisions

abstract:
  The azimuthal asymmetry of $J/\psi$ suppression in non-central heavy-ion
collisions is studied within a dynamic model of $J/\psi$ suppression in a
deconfined partonic medium. Within this model, $J/\psi$ suppression in
heavy-ion collisions is caused mainly by the initial state nuclear absorption
and dissociation via gluon-$J/\psi$ scattering in deconfined partonic medium.
Only the second mechanism gives arise to azimuthal asymmetry of the final
$J/\psi$ production. We demonstrate that if there is an onset of suppression by
quark-gluon plasma (QGP) in the NA50 data, it must be accompanied by the
non-vanishing azimuthal asymmetry. Using the same critical density above which
the QGP effect enters, we predict the azimuthal asymmetric coefficient $v_2$ as
well as the survival probability for $J/\psi$ at the RHIC energy.


title: (Strange) Meson Interferometry at RHIC

abstract:
  We make predictions for the kaon interferometry measurements in Au+Au
collisions at the Relativistic Heavy Ion Collider (RHIC). A first order phase
transition from a thermalized Quark-Gluon-Plasma (QGP) to a gas of hadrons is
assumed for the transport calculations. The fraction of kaons that are directly
emitted from the phase boundary is considerably enhanced at large transverse
momenta K_T ~ 1 GeV/c. In this kinematic region, the sensitivity of the
R_out/R_side ratio to the QGP-properties is enlarged. Here, the results of the
1-dimensional correlation analysis are presented. The extracted interferometry
radii, depending on $K_T$, are not unusually large and are strongly affected by
momentum resolution effects.


title:
Report by N. Dinh Dang, V. Kim Au, T. Suzuki, and A. Arima on the
  Comment by V. Yu. Ponomarev

abstract:
  In this report we've shown that the arguments, which the author of the
Comment presents to prove his case, are either wrong or irrelevant.


title: Photons from Quark Gluon Plasma and Hot Hadronic Matter

abstract:
  The productions of real photons from quark gluon plasma and hot hadronic
matter formed after the nucleus - nucleus collisions at ultra-relativistic
energies are discussed. The effects of the spectral shift of the hadrons at
finite temperature on the production of photons are investigated. On the basis
of the present analysis it is shown that the photon spectra measured by WA98
collaboration in Pb + Pb collisions at CERN SPS energies can be explained by
both QGP as well as hadronic initial states if the spectral shift of hadrons at
finite temperature is taken into account. Several other works on the analysis
of WA98 photon data have also been briefly discussed.


title: The role of interaction vertices in bound state calculations

abstract:
  In recent studies of the one and two-body Greens' function for scalar
interactions it was shown that crossed ladder and ``crossed rainbow'' (for the
one-body case) exchanges play a crucial role in nonperturbative dynamics. In
this letter we use exact analytical and numerical results to show that the
contribution of vertex dressings to the two-body bound state mass for scalar
QED are cancelled by the self-energy and wavefunction normalization. This
proves, for the first time, that the mass of a two-body bound state given by
the full theory can in a very good approximation be obtained by summing only
ladder and crossed ladder diagrams using a bare vertex and a constant dressed
mass. We also discuss the implications of the remarkable cancellation between
rainbow and crossed rainbow diagrams that is a feature of one-body
calculations.


title:
Study $\omega$ and $\phi$ photoproduction in the nucleon isotopic
  channels

abstract:
  We present results for the photoproduction of $\omega$ and $\phi$ meson in
the nucleon isotopic channles. A recently developed quark model with an
effective Lagrangian is employed to account for the non-diffractive {\it s}-
and {\it u}-channel processes; the diffractive feature arising from the {\it
natural} parity exchange is accounted for by the {\it t}-channel pomeron
exchange, while the {\it unnatural} parity exchange is accounted for by the
{\it t}-channel pion exchange. In the $\omega$ production, the isotopic effects
could provide more information concerning the search of "missing resonances",
while in the $\phi$ production, the isotopic effects could highlight
non-diffractive resonance excitation mechanisms at large angles.


title:
Collective Excitations and Pairing Effects in Drip-Line Nuclei --
  Continuum RPA in Coordinate-Space HFB --

abstract:
  We discuss novel features of a new continuum RPA formulated in the
coordinate-space Hartree-Fock-Bogoliubov framework. This continuum
quasiparticle RPA takes into account both the one- and two-particle escaping
channels. The theory is tested with numerical calculations for monopole, dipole
and quadrupole excitations in neutron-rich oxygen isotopes near the drip-line.
Effects of the particle-particle RPA correlation caused by the pairing
interaction are discussed in detail, and importance of the selfconsistent
treatment is emphasized.


title: Polarization effects in elastic electron-proton scattering

abstract:
  In these notes we present a detailed and complete scheme for the calculation
of polarization phenomena in elastic electron-nucleon scattering. The
longitudinal and transversal components of the polarization for the scattered
nucleon, induced by the scattering of longitudinally polarized electrons and
the asymmetries for the collision of polarized electrons with a polarized
nucleon target are included. The calculations are done in the framework of the
one-photon mechanism, in the Breit system, which is the most convenient for the
analysis of polarization effects. We briefly discuss the region of
applicability of such model and other mechanisms (radiative and electroweak
corrections) which may come into this idealized picture.


title: Spectral Function of rho in Dense and Hot Hadronic Matter

abstract:
  The spectral function of rho meson in hot/dense hadronic matter is studied by
taking into account the nucleon-loop on quantum hadrondynamics model level.
Different from the hot pion gas effect which changes the spectral function
slightly, the nucleon-antinucleon polarization (Dirac sea) makes the spectral
function very sharp and shifted towards the low invariant mass region
significantly due to the decreasing effective nucleon mass.


title:
Fusion of light exotic nuclei at near-barrier energies : effect of
  inelastic excitation

abstract:
  The effect of inelastic excitation of exotic light projectiles (proton- as
well as neutron-rich) $^{17}$F and $^{11}$Be on fusion with heavy target has
been studied at near-barrier energies. The calculations have been performed in
the coupled channels approach where, in addition to the normal coupling of the
ground state of the projectile to the continuum, inelastic excitation of the
projectile to the bound excited state and its coupling to the continuum have
also been taken into consideration. The inclusion of these additional couplings
has been found to have significant effect on the fusion excitation function of
neutron-rich $^{11}$Be on $^{208}$Pb whereas the effect has been observed to be
nominal for the case of proton-rich $^{17}$F on the same target. The pronounced
effect of the channel coupling on the fusion process in case of $^{11}$Be is
attributed to its well-developed halo structure.


title: Fusion of light proton-rich exotic nuclei at near-barrier energies

abstract:
  We study theoretically fusion of the light proton-rich exotic nuclei $^{17}$F
and $^8$B at near-barrier energies in order to investigate the possible role of
breakup processes on their fusion cross sections. To this end, coupled channel
calculations are performed considering the couplings to the breakup channels of
these projectiles. In case of $^{17}$F, the coupling arising out of the
inelastic excitation from the ground state to the bound excited state and its
couplings to the continuum have also been taken into consideration. It is found
that the inelastic excitation/breakup of $^{17}$F affect the fusion cross
sections very nominally even for a heavy target like Pb. On the other hand,
calculations for fusion of the one-proton halo nucleus $^8$B on a Pb target
show a significant suppression of the complete fusion cross section above the
Coulomb barrier. This is due to the larger breakup probability of $^8$B as
compared to that of $^{17}$F. However, even for $^8$B, there is little change
in the complete fusion cross sections as compared to the no-coupling case at
sub-barrier energies.


title:
Electromagnetic transitions between giant resonances within a
  continuum-RPA approach

abstract:
  A general continuum-RPA approach is developed to describe electromagnetic
transitions between giant resonances. Using a diagrammatic representation for
the three-point Green's function, an expression for the transition amplitude is
derived which allows one to incorporate effects of mixing of single and double
giant resonances as well as to take the entire basis of particle-hole states
into consideration. The radiative widths for E1 transition between the
charge-exchange spin-dipole giant resonance and Gamow-Teller states are
calculated for ^{90}Nb and ^{208}Bi nuclei. The importance of the mixing is
stressed.


title: Complete relativistic equation of state for neutron stars

abstract:
  We construct the equation of state (EOS) in a wide density range for neutron
stars using the relativistic mean field theory. The properties of neutron star
matter with both uniform and non-uniform distributions are studied
consistently. The inclusion of hyperons considerably softens the EOS at high
densities. The Thomas-Fermi approximation is used to describe the non-uniform
matter, which is composed of a lattice of heavy nuclei. The phase transition
from uniform matter to non-uniform matter occurs around $0.06 \rm{fm^{-3}}$,
and the free neutrons drip out of nuclei at about $2.4 \times 10^{-4}\
\rm{fm^{-3}}$. We apply the resulting EOS to investigate the neutron star
properties such as maximum mass and composition of neutron stars.


title:
The nuclear shell effects near the r-process path in the relativistic
  Hartree-Bogoliubov theory

abstract:
  We have investigated the evolution of the shell structure of nuclei in going
from the r-process path to the neutron drip line within the framework of the
Relativistic Hartree-Bogoliubov (RHB) theory. By introducing the quartic
self-coupling of $\omega$ meson in the RHB theory in addition to the non-linear
scalar coupling of $\sigma$ meson, we reproduce the available data on the shell
effects about the waiting-point nucleus $^{80}$Zn. With this approach, it is
shown that the shell effects at N=82 in the inaccessible region of the
r-process path become milder as compared to the Lagrangian with the scalar
self-coupling only. However, the shell effects remain stronger as compared to
the quenching exhibited by the HFB+SkP approach. It is also shown that in
reaching out to the extreme point at the neutron drip line, a terminal
situation arises where the shell structure at the magic number is washed out
significantly.


title: Three Quark Clusters in Hot and Dense Nuclear Matter

abstract:
  We present a relativistic in-medium three-body equation to study correlations
in hot and dense quark matter. The equation is solved for a zero-range force
for parameters close to the phase transition of QCD.


title:
The effect of early chemical freeze out on radial and elliptic flow from
  a full 3D hydrodynamic model

abstract:
  We investigate the effect of early chemical freeze-out on radial and elliptic
flow by using a fully three dimensional hydrodynamic model. We find that the
time evolution of temperature and the thermal freeze-out temperature dependence
of average radial flow are different from the results by using a conventional
hydrodynamic model in which chemical equilibrium is always assumed. We also
analyse the p_t spectrum and v_2(p_t) at the RHIC energy and consistently
reproduce experimental data by choosing the thermal freeze-out temperature T_th
= 140 MeV.


title: Coupled fermion and boson production in a strong background mean-field

abstract:
  We derive quantum kinetic equations for fermion and boson production starting
from a phi^4 Lagrangian with minimal coupling to fermions. Decomposing the
scalar field into a mean-field part and fluctuations we obtain spontaneous pair
creation driven by a self-interacting strong background field. The produced
fermion and boson pairs are self-consistently coupled. Consequently back
reactions arise from fermion and boson currents determining the time dependent
self-interacting background mean-field. We explore the numerical solution in
flux tube geometry for the time evolution of the mean-field as well as for the
number- and energy densities for fermions and bosons. We find that after a
characteristic time all energy is converted from the background mean-field to
particle creation. Applying this general approach to the production of
``quarks'' and ``gluons'' a typical time scale for the collapse of the flux
tube is 1.5 fm/c.


title: Statistical properties of fragment isospin in multifragmentation

abstract:
  It is shown that the chemical equilibrium condition of the system can be
unambiguously identified by analyzing the isospin evolution of fragments
produced in nuclear multifragmentation process. As far as the chemical
equilibrium is established, the isotope production can be used for finding
properties of nuclear matter and fragments in the freeze-out volume, for
example, via the isoscaling phenomenon.


title: Nucleon-Nucleon Scattering Observables in Large-$N_c$ QCD

abstract:
  Nucleon-nucleon scattering observables are considered in the context of the
large $N_c$ limit of QCD for initial states with moderately high momenta ($p
\sim N_c$). The scattering is studied in the framework of the time-dependent
mean-field approximation. We focus on the dependence of those observables on
the spin and isospin of the initial state which may be computed using
time-dependent mean-field theory. We show that, up to corrections, all such
observables must be invariant under simultaneous spin and isospin flips ({\it
i.e.} rotations through $\pi/2$ in both spin and isospin) acting on either
particle. All observables of this class obtained from spin unpolarized
measurements must be isospin independent up to $1/N_c$ corrections. Moreover,
it can be shown that the leading correction is of relative order $1/N_c^2$
rather than $1/N_c$.


title: The three-nucleon bound state using realistic potential models

abstract:
  The bound states of $^3$H and $^3$He have been calculated using the Argonne
$v_{18}$ plus the Urbana three-nucleon potential. The isospin $T=3/2$ state
have been included in the calculations as well as the $n$-$p$ mass difference.
The $^3$H-$^3$He mass difference has been evaluated through the charge
dependent terms explicitly included in the two-body potential. The calculations
have been performed using two different methods: the solution of the Faddeev
equations in momentum space and the expansion on the correlated hyperspherical
harmonic basis. The results are in agreement within 0.1% and can be used as
benchmark tests. Results for the CD-Bonn interaction are also presented. It is
shown that the $^3$H and $^3$He binding energy difference can be predicted
model independently.


title: Chiral restoration from pionic atoms?

abstract:
  We evaluate widths and shifts of pionic atoms using a theoretical
microscopical potential in which the pion decay constant $f_\pi$ is changed by
an in--medium density dependent one ($f_\pi(\rho)$), predicted by different
partial Chiral restoration calculations. We show that the results obtained for
shifts and widths are worse than if this modification were not implemented. On
the other hand, we argue that in microscopic many body approaches for the pion
selfenergy, based on effective Lagrangians, the mechanisms responsible for the
change of $f_\pi$ in the medium should be automatically incorporated.
Therefore, the replacement of $f_\pi$ by $f_\pi(\rho)$ in the many body
derivation of the microscopic potential would be inappropriate.


title: Chiral 2pi exchange at order four and peripheral NN scattering

abstract:
  We calculate the impact of the complete set of two-pion exchange
contributions at chiral order four (also known as
next-to-next-to-next-to-leading order, N3LO) on peripheral partial waves of
nucleon-nucleon scattering. Our calculations are based upon the analytical
studies by Kaiser. It turns out that the contribution of order four is
substantially smaller than the one of order three, indicating convergence of
the chiral expansion. We compare the prediction from chiral pion-exchange with
the corresponding one from conventional meson-theory as represented by the Bonn
Full Model and find, in general, good agreement. Our calculations provide a
sound basis for investigating the issue whether the low-energy constants
determined from pi-N lead to reasonable predictions for NN.


title:
Evaluation of Effective Astrophysical S factor for Non-Resonant
  Reactions

abstract:
  We derived analytic formulas of the effective S astrophysical S factor,S^eff
for a non-resonant reaction of charged particles using a Taylor expension of
the astrophysical S factor and a uniform approximation.The formulas will be
able to generate generate more accurate approximation to S^eff than previous
ones.


title: Anharmonicities of giant dipole excitations

abstract:
  The role of anharmonic effects on the excitation of the double giant dipole
resonance is investigated in a simple macroscopic model.Perturbation theory is
used to find energies and wave functions of the anharmonic ascillator.The cross
sections for the electromagnetic excitation of the one- and two-phonon giant
dipole resonances in energetic heavy-ion collisions are then evaluated through
a semiclassical coupled-channel calculation.It is argued that the variations of
the strength of the anharmonic potential should be combined with appropriate
changes in the oscillator frequency,in order to keep the giant dipole resonance
energy consistent with the experimental value.When this is taken into
account,the effects of anharmonicities on the double giant dipole resonance
excitation probabilities are small and cannot account for the well-known
discrepancy between theory and experiment.


title: Two-Body Bound States in Light-Front Dynamics

abstract:
  We present the main features of the explicitly covariant Light-Front Dynamics
formalism and a summary of our recent works on this topic. They concern the
bound states of two scalar particles in the Wick-Cutkosky model and of two
fermions interacting via the usual OBEP ladder kernels.


title: pion-rho-omega vertex in nuclear matter

abstract:
  Medium modifications of the pion-omega-rho vertex are analyzed in context of
the omega -> pi gamma* and rho -> pi gamma* decays in nuclear matter. A
relativistic hadronic model with mesons, nucleons, and Delta(1232)isobars is
applied. A substantial increase of the widths for the decays omega -> pi gamma*
and rho -> pi gamma* is found for photon virtualities in the range 0.3-0.6 GeV.
This enhancement has a direct importance for the description of dilepton yields
obtained in relativistic heavy-ion collisions.


title:
On the difference between proton and neutron spin-orbit splittings in
  nuclei

abstract:
  The latest experimental data on nuclei at $^{132}$Sn permit us for the first
time to determine the spin-orbit splittings of neutrons and protons in
identical orbits in this neutron-rich doubly-magic region and compare the case
to that of $^{208}$Pb. Using the new results, which are now consistent for the
two neutron-rich doubly magic regions, a theoretical analysis defines the
isotopic dependence of the mean field spin-orbit potential and leads to a
simple explicit expression for the difference between the spin-orbit splittings
of neutrons and protons. The isotopic dependence is explained in the framework
of different theoretical approaches.


title: Superfluidity with dressed nucleons

abstract:
  The gap equation with dressed propagators is solved in symmetric nuclear
matter. Nucleon self-energies are obtained within the self-consistent in medium
T matrix approximation. The off-shell gap equation is compared to an effective
quasiparticle gap equation with reduced interaction. At normal density, we find
a reduction of the superfluid gap from 6.5MeV to .45MeV when self-energy
effects are included.


title:
Comparison of Form Factors Calculated with Different Expressions for the
  Boost Transformation

abstract:
  The effect of different boost expressions is considered for the calculation
of the ground-state form factor of a two-body system made of scalar particles
interacting via the exchange of a scalar boson. The aim is to provide an
uncertainty range on methods employed in implementing these effects as well as
an insight on their relevance when an ``exact'' calculation is possible. Using
a wave function corresponding to a mass operator that has the appropriate
properties to construct the generators of the Poincar\'{e} algebra in the
framework of relativistic quantum mechanics, form factors are calculated using
the boost transformations pertinent to the instant, front and point forms of
this approach. Moderately and strongly bound systems are considered with masses
of the exchanged boson taken as zero, 0.15 times the constituent mass $m$, and
infinity. In the first and last cases, a comparison with ``exact'' calculations
is made (Wick-Cutkosky model and Feynman triangle diagram). Results with a
Galilean boost are also given. Momentum transfers up to $Q^2=100 m^2$ are
considered. Emphasis is put on the contribution of the single-particle current,
as usually done. It is found that the present point-form calculations of form
factors strongly deviate from all the other ones, requiring large contributions
from two-body currents. Different implementations of the point-form approach,
where the role of these two-body currents would be less important, are
sketched.


title: Dilepton decays of baryon resonances

abstract:
  Dalitz decay of baryon resonances is studied and expressions for the decay
width are derived for resonances with arbitrary spin and parity. Contributions
of the various terms in the transition matrix element are compared and
relevance of spin-parity and the resonance mass is discussed. Explicite
algebraic expressions are cited for spin$\le$5/2 resonances. The results can be
used in models of dielectron production in elementary reactions and heavy ion
collisions.


title:
The Density Matrix Renormalization Group Method and Large-Scale Nuclear
  Shell-Model Calculations

abstract:
  The particle-hole Density Matrix Renormalization Group (p-h DMRG) method is
discussed as a possible new approach to large-scale nuclear shell-model
calculations. Following a general description of the method, we apply it to a
class of problems involving many identical nucleons constrained to move in a
single large j-shell and to interact via a pairing plus quadrupole interaction.
A single-particle term that splits the shell into degenerate doublets is
included so as to accommodate the physics of a Fermi surface in the problem. We
apply the p-h DMRG method to this test problem for two $j$ values, one for
which the shell model can be solved exactly and one for which the size of the
hamiltonian is much too large for exact treatment. In the former case, the
method is able to reproduce the exact results for the ground state energy, the
energies of low-lying excited states, and other observables with extreme
precision. In the latter case, the results exhibit rapid exponential
convergence, suggesting the great promise of this new methodology even for more
realistic nuclear systems. We also compare the results of the test calculation
with those from Hartree-Fock-Bogolyubov approximation and address several other
questions about the p-h DMRG method of relevance to its usefulness when
treating more realistic nuclear systems.


title:
Quantum interference of rho0- and omega-mesons in the pi N -> e+e- N
  reaction

abstract:
  The study of the $\pi N\to \rho^0 N$ and $\pi N \to \omega N$ amplitudes
below and close to the vector meson production threshold ($1.4<\sqrt s <1.8$
GeV)reveals a rich structure arising from the presence of baryon resonances in
this energy range. These resonances are reflected in the interference pattern
of the $e^+e^-$ decays of the $\rho^0$- and $\omega$-mesons produced in $\pi^-
p$ and $\pi^+ n$ reactions. We discuss the shape and magnitude of the
$\rho^0$-$\omega$ interference in the $\pi^-p \to e^+e^- n$ and $\pi^+n \to
e^+e^- p$ reaction cross sections as functions of the total center of mass
energy $\sqrt s$. We find contrasted results: the interference is largely
destructive for the $\pi^-p \to e^+e^- n$ cross section but constructive for
the $\pi^+n \to e^+e^- p$ cross section. An experimental study of these
reactions would provide significant constraints on the coupling of vector
meson-nucleon channels to low-lying baryon resonances.


title: Total reaction cross sections for neutron-nucleus scattering

abstract:
  Neutron total reaction cross sections at 45, 50, 55, 60, 65, and 75 MeV from
nuclei 12C, 28Si, 56Fe, 90Zr, and 208Pb have been measured and are compared
with (microscopic) optical model predictions. The optical potentials were
obtained in coordinate space by full folding effective nucleon-nucleon
interactions with realistic nuclear ground state density matrices. Good to
excellent agreement is found.


title: Energy Loss of High $\pT{}$ Hadrons by Final Hadronic State

abstract:
  In the context of the `jet quenching' phenomena typically materialization of
the jet is assumed to take place in vacuum outside the reaction zone. On the
other hand quantum mechanical estimates give a hadronization time on the order
of only a few fm/c for jets materializing into hadrons with transverse momenta
of $\pT{} \leq 10 GeV$, which thus should well take place inside the fireball.
Typical (in-)elastic collisions of these high $\pT{}$ particles with the bulk
of hadrons of the fireball have a rather low invariant mass and are thus
nonperturbative. An analysis within an opacity expansion in the number of
collisions by means of the FRITIOF collision scheme for various hadrons will be
presented. It shows that late hadronic collisions can substantially account for
the modification of the high $\pT{} $-spectrum observed for central collisions
at RHIC.


title: Chemical Equilibration of Antihyperons

abstract:
  Rapid chemical equilibration of antihyperons by means of the interplay
between strong annihilation on baryons and the corresponding backreactions of
multi-mesonic (fusion-type) processes in the later, hadronic stage of an
ultrarelativistic heavy ion collision will be discussed. Explicit rate
calculations for a dynamical setup are presented. At maximum SPS energies
yields of each antihyperon specie are obtained which are consistent with
chemical saturated populations of $T \approx 150-160 $ MeV. The proposed
picture supports dynamically the popular chemical freeze-out parameters
extracted within thermal models.


title: A Relativistic Separable Potential to Describe Pairing in Nuclear Matter

abstract:
  Using the Dirac-Hartree-Fock-Bogoliubov approximation to study nuclear
pairing, we have found the short-range correlations of the Dirac $^1$S$_0$
pairing fields to be essentially identical to those of the two-nucleon virtual
state at all values of the baryon density. We make use of this fact to develop
a relativistic separable potential that correctly describes the pairing fields.


title: Scaling properties of the transverse mass spectra

abstract:
  Motivated from the formation of an initial state of gluon-saturated matter,
we discuss scaling relations for the transverse mass spectra at BNL's
Relativistic Heavy-Ion Collider (RHIC). We show on linear plots, that the
transverse mass spectra for various hadrons can be described by an universal
function. The transverse mass spectra for different centralities can be
rescaled into each other. Finally, we demonstrate that scaling is also present
in proton-antiproton collider data and compare it to scaling at RHIC.


title: Quasi free electro fission of 238U

abstract:
  We present the result of a theoretical study of the quasi free electrofission
of $^{238}$U. The exclusive differential cross sections for the quasi free
scattering reaction stage have been calculated in PWIA, using a
Macroscopic-Microscopic approach for the description of the proton bound
states. The nuclear shape was parametrized in terms of cassinian ovaloids. The
equilibrium deformation parameters have been calculated by minimizing the total
nuclear energy. In the calculation the axially deformed Woods-Saxon single
particle potential was used. The obtained single particle momentum
distributions were averaged over the nuclear symmetry axis direction. The
occupation numbers were calculated in the BCS approach. The fissility for the
single hole excited states of the residual nucleus $^{237}$% Pa was calculated
on the statistical theory grounds both without taking into account the
pre-equilibrium emission of the particle, and with preequilibrium emission in
the framework of the exciton model.


title: Comment on "Spectroscopy with Random and Displaced Random Ensembles"

abstract:
  We point out that the time reversal invariance, which was further interpreted
by Velazquez et al. using the behaviors of $E_{cI}$ and $\sigma_I^2$, can not
be the origin of the 0 g.s. dominance, as was pointed out previously by Bijker
et al, and that the discussion by Velazquez et al. using a displaced TBRE is
not true in general.


title: The antikaon nuclear potential in hot and dense matter

abstract:
  The antikaon optical potential in hot and dense nuclear matter is studied
within the framework of a coupled-channel self-consistent calculation taking,
as bare meson-baryon interaction, the meson-exchange potential of the J\"ulich
group. Typical conditions found in heavy-ion collisions at GSI are explored. As
in the case of zero temperature, the angular momentum components larger than
L=0 contribute significantly to the finite temperature antikaon optical
potential at finite momentum. It is found that the particular treatment of the
medium effects has a strong influence on the behavior of the antikaon potential
with temperature. Our self-consistent model, in which antikaons and pions are
dressed in the medium, gives a moderately temperature dependent antikaon
potential which remains attractive at GSI temperatures, contrary to what one
finds if only nuclear Pauli blocking effects are included.


title: On "the authentic damping mechanism" of the phonon damping model. II

abstract:
  This article continues a discussion raised in previous publications (LANL
preprint server, nucl-th/0202006 and nucl-th/0202020). I try to convince my
opponents that general arguments are not "my case" and may be applied to their
model.


title: Anti-Baryon Puzzle in Ultra-Relativistic Heavy-Ion Collisions

abstract:
  The evolution of (non-strange) antibaryon abundances in the hadronic phase of
central heavy-ion collisions is studied within a thermal equilibrium framework,
based on the well-established picture of subsequent chemical and thermal
freezeout. Due to large annihilation cross sections, antiprotons are, a priori,
not expected to comply with this scheme. However, we show that a significant
regeneration of their abundance occurs upon inclusion of the inverse reaction
of multipion fusion, $n_\pi\pi \to p\bar p$ (with $n_\pi$=5-6), necessary to
ensure detailed balance. Especially at SPS energies, the build-up of large
pion-chemical potentials between chemical and thermal freezeout reinforces this
mechanism, rendering the $\bar p/p$ ratio in reasonable agreement with the
observed one (reflecting chemical freezeout). Explicit solutions of the
pertinent rate equation, which account for chemical off-equilibrium effects,
corroborate this explanation.


title:
Field-theoretical description of the multichannel gamma-p scattering
  reaction in the Delta resonance region and determination of the magnetic
  moment of the Delta+ resonance

abstract:
  The cross-sections of the $\gamma p-\gamma' N'$, $\gamma p-\pi' N'$ and
$\gamma p-\gamma'\pi' N'$ reactions are calculated in the framework of the
field-theoretical one-particle ($\pi,\omega,\rho$-mesons, nucleon and
$\Delta$-resonance) exchange model. Unlike the other relativistic approaches,
our resulting amplitudes of the $\gamma p$ multichannel reactions require
one-variable covariant vertex functions as input ingredient and every diagram
of these amplitudes satisfies the current conservation condition in the Coulomb
gauge. The complete set of the model independent skeleton diagrams for the
${\gamma} p\to\gamma'\pi'N'$ reaction is presented. The separable model of the
$\pi N$ interaction is generalized to construct the spin 3/2 particle
propagator of the $\Delta$-resonance. This procedure allows to obtain the $\pi
N-\Delta$ form factor and $\Delta$ propagator directly from the $\pi N$
$P_{33}$ phase shifts. The numerical calculation of the differential cross
section of the $\gamma p-\gamma' N'$, $\gamma p-{\pi^o}' N'$ and $\gamma
p-\gamma'{\pi^o}'N'$ reactions are performed with two different separable
models of the $\Delta$ propagator and with the propagator of Breit-Wigner
shape. It is demonstrated that the numerical description of these reactions in
the $\Delta$-resonance region are very sensitive to the form of the
$\Delta$-propagator. The sensitivity of the cross-sections of the $\gamma
p\to\gamma'{\pi^o}'p'$ reaction to the magnitude of the $\Delta^+$ magnetic
moment is examined and the most convenient kinematical region for the
determination of the magnetic moment of the $\Delta^+$-resonance from the
forthcoming data is indicated.


title: Closed expressions for the nuclear moments in semi-leptonic processes

abstract:
  We discuss a general formalism needed for a unified description of the weak
and electromagnetic processes in nuclei which is based on the multipole
decomposition of the hadronic currents. The use of harmonic oscillator
single-particle basis, which is commonly employed in many-body nuclear
calculations, simplifies the relevant expressions. We present analytic formulas
for the corresponding radial integrals which enter the transition matrix
elements of one-body operators in various semi-leptonic nuclear processes. As
an example, we apply our formalism in order to simplify previous formalism
giving the nuclear moments for the $0\nu\beta\beta$ - decay. Our results for
the radial integrals refer to the 1s-0d-1p-0f model space.


title: Nuclear matrix elements for exclusive neutrino-nucleus reactions

abstract:
  The formalism describing (anti)neutrino-nucleus reaction cross-sections in
neutral- and charged-current processes is improved. Compact formulae for the
single-particle transition matrix elements, based on the multipole expansion
treatment of the relevant hadronic currents and the use of harmonic oscillator
basis, are presented. As an application, the nucleus $^{127}I$, a promising
target for detection of solar- and supernova-neutrinos as well as of cold dark
matter candidates, is considered. Our matrix elements refer to exclusive
processes of the charge-changing $^{127}I(\nu_l,l^-)^{127}Xe^{\star}$ reaction
and especially to the transition ${5/2}^+ \to {3/2}^+$ leading from the ground
state of $^{127}$I to the lowest excitation of $^{127}$Xe nucleus.


title:
From microscopic to macroscopic dynamics in mean-field theory: effect of
  neutron skin on fusion barrier and dissipation

abstract:
  In this work, we introduce a new method to reduce the microscopic mean-field
theory to a classical macroscopic dynamics during the initial stage of fusion
reactions. We show that TDHF (Time-dependent Hartree-Fock) could be a useful
tool to gain information on fusion barriers as well as on one-body dissipation
effects. We apply the mean-field theory to the case of head-on reaction between
$^{16}$O and $^{16,22,24,28}$O in order to quantify the effect of neutron skin
on fusion. We show that the determination of fusion barrier requires, in
addition to a precise knowledge of the relative distance between the center of
mass of the two fusing nuclei, the introduction of an additional collective
coordinate that explicitly breaks the neutron-proton symmetry. In this context,
we estimate the position, height and diffuseness of the barrier as well as the
one-body friction and show that a global enhancement of the fusion
cross-section is expected in neutron rich nuclei.


title:
Spin dependent momentum distributions of proton-deuteron clusters in 3He
  from electron scattering on polarized 3He: theoretical predictions

abstract:
  The process $\overrightarrow{^3{\rm He}}(e,e'\vec{p})d $ (or
$\overrightarrow{^3{\rm He}}(e,e'\vec{d})p $) is studied theoretically in a
Faddeev treatment with the aim to have access to the spin-dependent momentum
distribution of ${\vec p} {\vec d} $ clusters in polarized $^3$He. Final state
interactions and meson exchange currents turn out to have a strong influence in
the considered kinematical regime (below the pion threshold). This precludes
the direct access to the momentum distribution except for small deuteron
momenta. Nevertheless, the results for the longitudinal and transverse response
functions are interesting as they reflect our present day understanding of the
reaction mechanism and therefore data would be very useful.


title:
Comparison of various models of particle multiplicity distributions
  using a general form of the grand canonical partition function

abstract:
  Various phenomenological models of particle multiplicity distributions are
discussed using a general form of the grand canonical partition function. These
phenomenological models include a wide range of varied processes such as
coherent emission or Poisson processes, chaotic emission resulting in a
negative binomial distribution, combinations of coherent and chaotic processes
called signal/noise distributions, and models based on field emission from
Lorentzian line shapes leading to Lorentz/Catalan distributions. These specific
cases can be written as special cases of a more general distribution. Using
this grand canonical approach moments and cumulants, combinants, hierarchical
structure, void scaling relations, KNO scaling features, clan variables and
branching laws associated with stochastic or ancestral variables are discussed.
It is shown that just looking at the mean and fluctuation of data is not enough
to distinguish these distributions or the underlying mechanism. A
generalization of the Poisson transform of a distribution and the Poissonian
decomposition of it into a compound or sequential process is also given.


title: Evaluation of QCD sum rules for HADES

abstract:
  QCD sum rules are evaluated at finite nucleon densities and temperatures to
determine the change of pole mass parameters for the lightest vector mesons
$\rho$, $\omega$ and $\phi$ in a strongly interacting medium at conditions
relevant for the starting experiments at HADES. The role of the four-quark
condensate is highlighted. A few estimates (within a fire ball model and BUU
calculations) of dilepton spectra in heavy-ion collisions at 1 AGeV are
presented.


title: Pion photoproduction on the nucleon in the quark model

abstract:
  We present a detailed quark-model study of pion photoproduction within the
effective Lagrangian approach. Cross sections and single-polarization
observables are investigated for the four charge channels, $\gamma p\to \pi^+
n$, $\gamma n\to \pi^- p$, $\gamma p\to \pi^0 p$, and $\gamma n\to \pi^0 n$.
Leaving the $\pi N\Delta$ coupling strength to be a free parameter, we obtain a
reasonably consistent description of these four channels from threshold to the
first resonance region. Within this effective Lagrangian approach, strongly
constrainted by the quark model, we consider the issue of double-counting which
may occur if additional {\it t}-channel contributions are included.


title:
Comment on "Forward K+ production in subthreshold pA collisions at 1.0
  GeV"

abstract:
  A Comment on the letter by V. Koptev, et al. - Phys. Rev. Lett. 87 (2001)
022301.


title:
From meson- and photon-nucleon scattering to vector mesons in nuclear
  matter

abstract:
  We present a relativistic and unitary approach to pion- and photon-nucleon
scattering taking into account the $\pi N$, $\rho N$, $\omega N$, $\eta N$,
$\pi\Delta$, $K \Lambda$ and $K \Sigma$ channels. Our scheme dynamically
generates the s- and d-wave nucleon resonances N(1535), N(1650), N(1520) and
N(1700) and isobar resonances $\Delta(1620)$ and $\Delta(1700)$ in terms of
quasi-local two-body interaction terms. We obtain a fair description of the
experimental data relevant for slow vector-meson propagation in nuclear matter.
The s-wave $\rho $- and $\omega $-meson nucleon scattering amplitudes, which
define the leading density modification of the $\rho$- and $\omega $-meson
spectral functions in nuclear matter, are predicted.


title: The $\rho NN$ coupling with direct coupling and loops

abstract:
  Starting from a gauge formalism of $\rho$ mesons, pions and baryons we
evaluate the $\rho$ coupling to the nucleon, including the direct coupling
provided by the Lagrangians, plus contributions from loops with the virtual
pion cloud. We find a contribution to the magnetic $\rho$ coupling to the
nucleon from pionic loops of the same size as the direct coupling, which is,
however, still small compared to the empirical values. This finding goes in
line with chiral formulations of the strong interaction of mesons at low
energies where, unlike the scalar mesons which are mostly built of a pion
(kaon) cloud, the $\rho$ meson stands as a genuine QCD state with intrinsic
properties not tied to those of the pion cloud.


title: Neutron star properties with in-medium vector mesons

abstract:
  We explore the impact of in-medium modification of the properties of vector
mesons on the nuclear equation of state and neutron star properties. It is
found that in-medium modifications stiffen the nuclear equation of state
considerably. If this feature has its correspondence in the full treatment of
dense hadronic matter, then very little room is left for the existence of
exotic phases like quark matter or boson condensates in the centers of neutron
stars of canonical mass.


title: Anisotropic flow from AGS to RHIC

abstract:
  The recent results on anisotropic flow in ultrarelativistic nuclear
collisions along with recent methodical developments and achievements in the
understanding of the phenomena, are reviewed. The emphasis is given to the
elliptic flow results.


title: Potential renormalization by tunneling induced intrinsic transition

abstract:
  The screening effects by bound target electrons in low energy nuclear
reactions in laboratory experiments can be well represented in terms of a
constant shift of the tunneling potential barrier as postulated in all previous
analyses if the electronic cloud were static or structureless and lied outside
the tunneling region. In this paper, using a semiclassical mean field analysis
of a simple two-level coupled-channels problem, we suggest that there could
occur a strong quantum transition of electrons from excited to the ground
states in the tunneling region, leading to a spatially dependent screening
potential. We thus show the necessity of the dynamical treatment of the
tunneling region in order to properly assess the screening effects by bound
target electrons in low energy nuclear reactions in laboratories.


title: Sigma photoproduction in the resonance region

abstract:
  A study of p(gamma,K)Sigma processes in an isobar model at tree level is
reported. By comparing model calculations to the published SAPHIR data, we
explore the possible role of different isospin I=1/2 (N*) and I=3/2 (Delta*)
resonances in the reaction dynamics. In our analysis, the inclusion of the
``missing'' D_{13}(1895) resonance does only slightly improve the global
description of the Sigma photoproduction data. More convincing signals for the
presence of such a ``missing'' resonance emerged in the analysis of the isospin
related p(gamma,K+)Lambda reaction. Various implementations of the nonresonant
part of the Sigma photoproduction amplitude are presented. The sensitivity of
the computed observables and extracted resonance parameters to the
uncertainties inherent to the treatment of the nonresonant (background)
diagrams are discussed.


title: Negative specific heat in out-of-equilibrium nonextensive systems

abstract:
  We discuss the occurrence of negative specific heat in a nonextensive system
which has an equilibrium second-order phase transition.The specific heat is
negative only in a transient regime before equilibration, in correspondence to
long-lasting metastable states. For these states standard equilibrium
Bolzmann-Gibbs thermodynamics does not apply and the system shows non-Gaussian
velocity distributions, anomalous diffusion and correlation in phase space.
Similar results have recently been found also in several other nonextensive
systems, supporting the general validity of this scenario. These models seem
also to support the conjecture that a nonexstensive statistical formalism, like
the one proposed by Tsallis, should be applied in such cases. The theoretical
scenario is not completely clear yet, but there are already many strong
theoretical indications suggesting that, it can be wrong to consider the
observation of an experimental negative specific heat as an unique and
unambiguous signature of a standard equilibrium first-order phase transition.


title: Interplay of Three-Body Interactions in the EOS of Nuclear Matter

abstract:
  The equation of state of symmetric nuclear matter has been investigated
within Brueckner approach adopting the charge-dependent Argonne $V_{18}$
two-body force plus a microscopic three-body force based on a meson-exchange
model. The effects on the equation of state of the individual processes giving
rise to the three-body force are explored up to high baryonic density. It is
found that the major role is played by the competition between the strongly
repulsive $(\sigma, \omega)$ exchange term with virtual nucleon-antinucleon
excitation and the large attractive contribution due to $(\sigma, \omega)$
exchange with $N^*(1440)$ resonance excitation. The net result is a repulsive
term which shifts the saturation density corresponding to the only two-body
force much closer to the empirical value, while keeping constant the saturation
energy per particle. The contribution from $(\pi, \rho)$ exchange 3BF is shown
to be attractive and rather small. The analysis of the separate three-body
force contributions allows to make a comparison with the prediction of
Dirac-Brueckner approach which is supposed to incorporate via the {\it dressed}
Dirac spinors the same virtual nucleon-antinucleon excitations as in the
present three-body force. The numerical results suggest that the three-body
force components missing from the Dirac-Brueckner approach are not negligible,
especially at high density. The calculation of the nuclear mean field and the
effective mass shows that the three-body force affects to a limited extent such
properties.


title: Microscopic three-body force for asymmetric nuclear matter

abstract:
  Brueckner calculations including a microscopic three-body force have been
extended to isospin asymmetric nuclear matter. The effects of the three-body
force on the equation of state and on the single-particle properties of nuclear
matter are discussed with a view to possible applications in nuclear physics
and astrophysics. It is shown that, even in the presence of the three-body
force, the empirical parabolic law of the energy per nucleon vs isospin
asymmetry $\beta=(N-Z)/A$ is fulfilled in the whole asymmetry range
$0\le\beta\le 1$ up to high densities. The three-body force provides a strong
enhancement of symmetry energy increasing with the density in good agreement
with relativistic approaches. The Lane's assumption that proton and neutron
mean fields linearly vary vs the isospin parameter is violated at high density
in the presence of the three-body force. Instead the momentum dependence of the
mean fields is rather insensitive to three body force which brings about a
linear isospin deviation of the neutron and proton effective masses. The
isospin effects on multifragmentation events and collective flows in heavy-ion
collisions are briefly discussed along with the conditions for direct URCA
processes to occur in the neutron-star cooling.


title:
Lectures on Effective Field Theories for Nuclei, Nuclear Matter and
  Dense Matter

abstract:
  This note is based on four lectures that I gave at the 10th Taiwan Nuclear
Spring School held at Hualien, Taiwan in January 2002. It aims to correlate the
old notion of Cheshire Cat Principle developed for elementary baryons to the
modern notion of quark-baryon and gluon-meson "continuities" or "dualities" in
dilute and dense many-body systems and predict what would happen to mesons when
squeezed by nuclear matter to high density as possibly realized in compact
stars. Using color-flavor locking in QCD, the vector mesons observed at low
density can be described as the Higgsed gluons dressed by cloud of collective
modes, i.e., pions just as they are in superdense matter, thus showing the
equivalence between hidden $flavor$ gauge symmetry and explicit $color$ gauge
symmetry. Instead of going into details of well-established facts, I focus on a
variety of novel ideas -- some solid and some less -- that could be confirmed
or ruled out in the near future.


title: Projection and ground state correlations made simple

abstract:
  We develop and test efficient approximations to estimate ground state
correlations associated with low- and zero-energy modes. The scheme is an
extension of the generator-coordinate-method (GCM) within Gaussian overlap
approximation (GOA). We show that GOA fails in non-Cartesian topologies and
present a topologically correct generalization of GOA (topGOA). An RPA-like
correction is derived as the small amplitude limit of topGOA, called topRPA.
Using exactly solvable models, the topGOA and topRPA schemes are compared with
conventional approaches (GCM-GOA, RPA, Lipkin-Nogami projection) for
rotational-vibrational motion and for particle number projection. The results
shows that the new schemes perform very well in all regimes of coupling.


title: The $\eta$-3N problem with separable interactions

abstract:
  The $\eta$-3N-interaction is studied within the four-body Faddeev-Yakubovsky
theory adopting purely separable forms for the two- and three-body
subamplitudes, limiting the basic two-body interactions to s-waves only. The
corresponding separable approximation for the integral kernels is obtained by
using the Hilbert-Schmidt procedure. Results are presented for the $\eta$-$^3$H
scattering amplitude and for the total elastic cross section for energies below
the triton break-up threshold.


title:
Predictions of total and total reaction cross sections for
  nucleon-nucleus scattering up to 300 MeV

abstract:
  Total reaction cross sections are predicted for nucleons scattering from
various nuclei. Projectile energies to 300 MeV are considered. So also are mass
variations of those cross sections at selected energies. All predictions have
been obtained from coordinate space optical potentials formed by full folding
effective two-nucleon (NN) interactions with one body density matrix elements
(OBDME) of the nuclear ground states. Good comparisons with data result when
effective NN interactions defined by medium modification of free NN t matrices
are used. Coupled with analyses of differential cross sections, these results
are sensitive to details of the model ground states used to describe nuclei.


title: Bethe-Salpeter equation and a nonperturbative quark-gluon vertex

abstract:
  A Ward-Takahashi identity preserving Bethe-Salpeter kernel can always be
calculated explicitly from a dressed-quark-gluon vertex whose diagrammatic
content is enumerable. We illustrate that fact using a vertex obtained via the
complete resummation of dressed-gluon ladders. While this vertex is planar, the
vertex-consistent kernel is nonplanar and that is true for any dressed vertex.
In an exemplifying model the rainbow-ladder truncation of the gap and
Bethe-Salpeter equations yields many results; e.g., pi- and rho-meson masses,
that are changed little by including higher-order corrections. Repulsion
generated by nonplanar diagrams in the vertex-consistent Bethe-Salpeter kernel
for quark-quark scattering is sufficient to guarantee that diquark bound states
do not exist.


title: Omega photoproduction beyond the resonance region at small u

abstract:
  Within the meson exchange model we study $\omega$ meson photoproduction at
energies above the s channel resonance region. Different model prescriptions
for the $\omega{NN}$ vertex function are investigated imposing gauge invariance
as well as crossing symmetry. The calculations reproduce the energy dependence
of the differential $\omega$ photoproduction cross sections at moderate $|u|$
for $E_\gamma{\le}4.7$ GeV, which previously were discussed as an indication of
the hard interaction between the photon and quarks of the nucleon.


title:
Probing the interactions of charmed mesons with nuclei in $\bar p$
  induced reactions

abstract:
  We study the perspectives of resonant and nonresonant charmed meson
production in $\bar{p} + A$ reactions within the Multiple Scattering Monte
Carlo (MSMC) approach. We calculate the production of the resonances
$\Psi(3770), \Psi(4040)$ and $\Psi(4160)$ on various nuclei, their propagation
and decay to $D, \bar{D}, D^*, \bar{D}^*, D_s, \bar{D}_s$ in the medium and
vacuum, respectively. The modifications of the open charm vector mesons in the
nuclear medium are found to be rather moderate or even small such that dilepton
spectroscopy will require an invariant mass resolution of a few MeV.
Furthermore, the elastic and inelastic interactions of the open charm mesons in
the medium are taken into account, which can be related to $(u,d)$-, $s$- or
$c$-quark exchange with nucleons. It is found that by studying the $D/\bar{D}$
ratio for low momenta in the laboratory ($\leq 2-2.2$ GeV/c) as a function of
target mass $A$ stringent constraints on the $c$-quark exchange cross section
can be obtained. On the other hand, the ratios
  $D^-_s/D^+_s$ as well as $D/D^-_s$ and $D/D^+_s$ at low momenta as a function
of $A$ will permit to fix independently the strength of the $s$-quark exchange
reaction in $D^-_s N$ scattering.


title: Neutron-proton interaction in rare-earth nuclei: Role of tensor force

abstract:
  We investigate the role of the tensor force in the description of doubly odd
deformed nuclei within the framework of the particle-rotor model. We study the
rare-earth nuclei 174Lu, 180Ta, 182Ta, and 188Re using a finite-range
interaction, with and without tensor terms. Attention is focused on the lowest
K=0 and K=1 bands, where the effects of the residual neutron-proton interaction
are particularly evident. Comparison of the calculated results with
experimental data evidences the importance of the tensor-force effects.


title: Phi meson production in relativistic heavy ion collisions

abstract:
  Within a multiphase transport model we study phi meson production in
relativistic heavy ion collisions from both superposition of initial multiple
proton-proton interactions and the secondary collisions in the produced
hadronic matter. The yield of phi mesons is then reconstructed from their
decaying product of either the kaon-antikaon pairs or the dimuon pairs. Since
the kaon-antikaon pairs at midrapidity with low transverse momenta are
predominantly rescattered or absorbed in the hadronic medium, they can not be
used to reconstruct the phi meson and lead thus to a smaller reconstructed phi
meson yield than that reconstructed from the dimuon channel. With in-medium
mass modifications of kaons and phi mesons, the phi yield from dimuons is
further enhanced compared to that from the kaon-antikaon pairs. The model
result is compared with the experimental data at the CERN/SPS and RHIC energies
and its implications to quark-gluon plasma formation are discussed.


title:
Chiral corrections to the isovector double scattering term for the
  pion-deuteron scattering length

abstract:
  The empirical value of the real part of the pion-deuteron scattering length
can be well understood in terms of the dominant isovector $\pi N$-double
scattering contribution. We calculate in chiral perturbation theory all
one-pion loop corrections to this double scattering term which in the case of
$\pi N$-scattering close the gap between the current-algebra prediction and the
empirical value of the isovector threshold T-matrix $T_{\pi N}^-$. In addition
to closing this gap there is in the $\pi d$-system a loop-induced off-shell
correction for the exchanged virtual pion. Its coordinate space representation
reveals that it is equivalent to $2\pi$-exchange in the deuteron. We evaluate
the chirally corrected double scattering term and the off-shell contribution
with various realistic deuteron wave functions. We find that the off-shell
correction contributes at most -8% and that the isovector double scattering
term explains at least 90% of the empirical value of the real part of the $\pi
d$-scattering length.


title: Bulk Nuclear Properties from Reactions

abstract:
  Extraction of bulk nuclear properties by comparing reaction observables to
results from semiclassical transport-model simulations is discussed. Specific
properties include the nuclear viscosity, incompressibility and constraints on
the nuclear pressure at supranormal densities.


title: On the existence of a bound tetraneutron

abstract:
  Following recent work in which events which may correspond to a bound
tetraneutron ($^4$n) were observed, it is pointed out that from the theoretical
perspective the two-body nucleon-nucleon force cannot by itself bind four
neutrons, even if it can bind a dineutron.
  A very strong phenomenological four-nucleon (4N) force is needed in order to
bind the tetraneutron. Such a 4N force, if it existed, would bind $^4$He by
about 100 MeV. Alternative experiments such as ($^8$He,$^4$n) are proposed to
search for the tetraneutron.


title:
Can hadronic rescattering explain the large elliptic flow and small HBT
  radii seen at RHIC?

abstract:
  Results from the data obtained in the first physics run of the Relativistic
Heavy Ion Collider (RHIC) have shown suprisingly large elliptic flow and
suprisingly small HBT radii. Attempts to explain both results in a consistant
picture have so far been unsuccessful. The present work shows that a thermal
model + hadronic rescattering calculation can explain both elliptic flow and
HBT results from RHIC. The calculation requires a very early hadronization time
of about 1 fm/c after the initial collision of the nuclei.


title: Phi-measure and Disoriented chiral condensates

abstract:
  Fluctuations in the ratio of neutral to charged pions arising due to
formation of disoriented chiral condensates (DCC) are discussed using the
Phi-measure. The properties of the measure for various cases of DCC and non-DCC
are discussed. The effect of detector efficiencies and other experimental
factors are presented. Application of the Phi-measure to simulated data, within
the context of a simple DCC model are also discussed.