title: Nuclear Equation of State and Neutron Star Structure

abstract:
  The hadronic equation of state for a neutron star is discussed with a
particular emphasis on the symmetry energy. The results of several microscopic
approaches are compared and also a new calculation in terms of the
self-consistent Green function method is presented. In addition possible
constraints on the symmetry energy coming from empirical information from the
neutron skin of finite nuclei are considered.


title: Dynamical Generation of Hyperon Resonances

abstract:
  In this talk we report on how, using a chiral unitary approach for the
meson--baryon interactions, two octets of $J^{\pi}=1/2^-$ baryon states and a
singlet are generated dynamically, resulting in the case of strangeness $S=-1$
in two poles of the scattering matrix close to the nominal $\Lambda(1405)$
resonance. We suggest experiments which could show evidence for the existence
of these states.


title:
Using the $K^+p\to \pi^+K^+n$ reaction to determine the $\Theta^+$
  quantum numbers

abstract:
  We study the $K^+p\to \pi^+K^+n$ reaction with some kinematics suited to the
production of the $\Theta^+$ resonance recently observed and show that the
measurement of cross sections and polarization observables can shed light on
the spin,isospin and parity of the $\Theta^+$ state.


title: Multi-strange baryon production in Au+Au collisions near threshold

abstract:
  The centrality dependence of Xi^- and Lambda production in Au+Au interactions
at E_lab=6 AGeV is studied within a microscopic transport approach. In line
with recent data, a slight enhancement of the Xi^-/(Lambda+Sigma^0) ratio
toward central collisions is found. It is demonstrated that the observed
production of multiple strange baryons can be traced back to multi-step
meson-baryon interactions in the late stages of the collisions. Therefore, the
present analysis supports an interpretation of the observed Xi abundance in
terms of hadronic re-scattering.


title: Thermal Color-superconducting Fluctuations in Dense Quark Matter

abstract:
  Thermal fluctuations of the color superconducting order parameter in dense
quark matter are investigated in terms of the phenomenological Ginzburg -
Landau approach. Our estimates show that fluctuations of the di-quark gap may
strongly affect some of thermodynamic quantities even far below and above the
critical temperature. If the critical temperature $T_c$ of the di-quark phase
transition were rather high ($\gsim (50\div 70)$ MeV) one could expect a
manifestation of fluctuations of the di-quark gap in the course of heavy ion
collisions (above $T_c$). For $T_c \sim 50 $MeV color superconducting
fluctuations may also affect an initial stage of the hybrid star evolution.


title: Pion re-scattering in pi0 production

abstract:
  This work discusses the approximations frequently used to calculate the
contribution to pion production in proton-proton scattering near threshold from
irreducible pion re-scattering. The reference result is obtained from the
quantum mechanical reduction of the corresponding Feynman diagram to
Time-Ordered Field Theory diagrams. We conclude that the Distorted Wave Born
Approximation is quite adequate at threshold energies and even above. We
discuss the choices for the energy of the exchanged pion, both for its
propagator and for the piN amplitude describing the re-scattering vertex. The
calculation employs a physical model for nucleons and pions -- pseudo-vector
coupling for the piNN vertex and realistic amplitudes for the piN re-scattering
and for the NN transitions in the initial and final states.


title:
Supersymmetric Patterns in the Pseudospin Spin and Coulomb Limits of the
  Dirac Equation with Scalar and Vector Potentials

abstract:
  We show that the Dirac equation in 3+1 dimensions gives rise to
supersymmetric patterns when the scalar and vector potentials are (i) Coulombic
with arbitrary strengths or (ii) when their sum or difference is a constant,
leading to relativistic pseudospin and spin symmetries. The conserved
quantities and the common intertwining relation responsible for such patterns
are discussed.


title:
Different particle alignments in N \approx Z Ru isotopes studied by the
  shell model

abstract:
  Experimentally observed heaviest $N \approx Z$ nuclei, Ru isotopes, are
investigated by the shell model on a spherical basis with the extended $P+QQ$
Hamiltonian. The energy levels of all the Ru isotopes can be explained by the
shell model with a single set of force parameters.
  The calculations indicate enhancement of quadrupole correlations in the $N=Z$
nucleus $^{88}$Ru as compared with the other Ru isotopes, but the observed
moments of inertia seem to require much more enhancement of quadrupole
correlations in $^{88}$Ru. It is discussed that the particle alignment takes
place at $8^+$ in $^{90}$Ru but is delayed in $^{88}$Ru till $16^+$ where the
simultaneous alignments of proton and neutron pairs take place.
  The calculations present interesting predictions for $^{89}$Ru that the
ground state is the $1/2^-$ state and there are three $\Delta J=2$ bands with
different particle alignments including the T=0 $p-n$ pair alignment.


title: Unmasking the nuclear matter equation of state

abstract:
  Accurately calibrated (or ``best fit'') relativistic mean-field models are
used to compute the distribution of isoscalar monopole strength in 90Zr and
208Pb, and the isovector dipole strength in 208Pb using a continuum
random-phase-approximation approach. It is shown that the distribution of
isoscalar monopole strength in 208Pb--but not in 90Zr--is sensitive to the
density dependence of the symmetry energy. This sensitivity hinders the
extraction of the compression modulus of symmetric nuclear matter from the
isoscalar giant monopole resonance (ISGMR) in 208Pb. Thus, one relies on 90Zr,
a nucleus with both a small neutron-proton asymmetry and a well developed ISGMR
peak, to constrain the compression modulus of symmetric nuclear matter to the
range K=(248 +/- 6) MeV. In turn, the sensitivity of the ISGMR in 208Pb to the
density dependence of the symmetry energy is used to constrain its neutron skin
to the range Rn-Rp<=0.22 fm. The impact of this result on the enhanced cooling
of neutron stars is briefly addressed.


title:
The three-body problem with short-range forces: renormalized equations
  and regulator-independent results

abstract:
  We discuss effective field theory treatments of the problem of three
particles interacting via short-range forces. One case of such a system is
neutron-deuteron scattering at low energies. We demonstrate that in attractive
channels the renormalization-group evolution of the 1+2 scattering amplitude
may be complicated by the presence of eigenvalues greater than unity in the
kernel. We also show that these eigenvalues can be removed from the kernel by
one subtraction, resulting in an equation which is renormalization-group
invariant. A unique solution for 1+2 scattering phase shifts is then obtained.
We give an explicit demonstration of our procedure for both the case of three
spinless bosons and the case of the doublet channel in nd scattering. After the
contribution of the two-body effective range is included in the effective field
theory, it gives a good description of the nd doublet phase shifts below
deuteron breakup threshold.


title: Exploring the nucleus in the context of low-energy QCD

abstract:
  These lecture notes address a central problem of theoretical nuclear physics:
how to establish a relationship between low-energy, non-perturbative QCD and
nuclear phenomenology which includes both nuclear matter and finite nuclei. We
develop a microscopic covariant description of nuclear many-body dynamics
constrained by chiral symmetry and in-medium QCD sum rules. A relativistic
point-coupling model is derived, based on an effective Lagrangian with
density-dependent contact interactions between nucleons. These interactions are
constructed from chiral one- and two-pion exchange, combined with the large
isoscalar nucleon self-energies that arise through changes in the quark
condensate and the quark density at finite baryon density. Nuclear binding and
saturation are almost completely generated by chiral (two-pion exchange)
fluctuations in combination with Pauli effects, whereas strong scalar and
vector fields of about equal magnitude and opposite sign, induced by changes of
the QCD vacuum in the presence of baryonic matter, generate the large effective
spin-orbit potential in finite nuclei. Promising results are found for the
nuclear matter equation of state and for the bulk and single-nucleon properties
of finite nuclei.


title:
Solving Potential Scattering Equations without Partial Wave
  Decomposition

abstract:
  Considering two-body integral equations we show how they can be dimensionally
reduced by integrating exactly over the azimuthal angle of the intermediate
momentum. Numerical solution of the resulting equation is feasible without
employing a partial-wave expansion. We illustrate this procedure for the
Bethe-Salpeter equation for pion-nucleon scattering and give explicit details
for the one-nucleon-exchange term in the potential. Finally, we show how this
method can be applied to pion photoproduction from the nucleon with $\pi N$
rescattering being treated so as to maintain unitarity to first order in the
electromagnetic coupling. The procedure for removing the azimuthal angle
dependence becomes increasingly complex as the spin of the particles involved
increases.


title:
Observable implications of geometrical and dynamical aspects of
  freeze-out in heavy ion collisions

abstract:
  Using an analytical parameterization of hadronic freeze-out in relativistic
heavy ion collisions, we present a detailed study of the connections between
features of the freeze-out configuration and physical observables. We focus
especially on anisotropic freeze-out configurations (expected in general for
collisions at finite impact parameter), azimuthally-sensitive HBT
interferometry, and final-state interactions between non-identical particles.
Model calculations are compared with data taken in the first year of running at
RHIC; while not perfect, good agreement is found, raising the hope that a
consistent understanding of the full freeze-out scenario at RHIC is possible,
an important first step towards understanding the physics of the system prior
to freeze-out.


title:
Observable effects of symmetry energy in heavy-ion collisions at RIA
  energies

abstract:
  Within an isospin-dependent transport model for nuclear reactions induced by
neutron-rich nuclei, we perform a comparative study of $^{100}Sn+^{124}Sn$ and
$^{100}Zn+^{124}Sn$ reactions at beam energies of 30 MeV/A and 400 MeV/A to
identify optimal experimental conditions and observables for investigating the
equation of state (EOS) of neutron-rich matter at RIA. Several observables
known to be sensitive to the density-dependence of the symmetry energy are
examined as a function of impact parameter for both reaction systems. In
particular, the strength of isospin transport/diffusion is studied by using
rapidity distributions of free nucleons and their isospin asymmetries. An
approximate isospin equilibrium is established even for peripheral collisions
with a very soft symmetry energy at 30 MeV/A. At 400 MeV/A, however, a strong
isospin translucency is observed even in most central collisions with either
soft or stiff symmetry energies. Origins of these observations and their
implications to determining the EOS of neutron-rich matter at the Rare Isotope
Accelerator (RIA) are discussed.


title:
Probing the EOS of dense neutron-rich matter with high-energy
  radioactive beams

abstract:
  Nuclear reactions induced by high energy radioactive beams create a transient
state of nuclear matter with high density and appreciable neutron to proton
asymmetry. This will provide a unique opportunity to explore novel properties
of dense neutron-rich matter and the isospin-dependence of the nuclear equation
of state (EOS). Here we study the $\pi^-/\pi^+$ ratio as a probe of the EOS of
dense neutron-rich matter.


title:
A systematic study of Zr and Sn isotopes in the Relativistic Mean Field
  theory

abstract:
  The ground-state properties of Zr and Sn isotopes are studied within the
relativistic mean field theory. Zr and Sn isotopes have received tremendous
attention due to various reasons, including the predicted giant halos in the
neutron-rich Zr isotopes, the unique feature of being robustly spherical in the
region of $^{100}$Sn $\sim$ $^{132}$Sn and the particular interest of Sn
isotopes to nuclear astrophysics. Furthermore, four (semi-) magic neutron
numbers, 40, 50, 82 and 126, make these two isotopic chains particularly
important to test the pairing correlations and the deformations in a
microscopic model. In the present work, we carry out a systematic study of Zr
and Sn isotopes from the proton drip line to the neutron drip line with
deformation effects, pairing correlations and blocking effects for nuclei with
odd number of neutrons properly treated. A constrained calculation with
quadrupole deformations is performed to find the absolute minimum for each
nucleus on the deformation surface. All ground-state properties, including the
separation energies, the odd-even staggerings, the nuclear radii, the
deformations and the single-particle spectra are analyzed and discussed in
detail.


title: Loosely bound three-body nuclear systems in the J-matrix approach

abstract:
  We discuss the extension of the oscillator-basis $J$-matrix formalism on the
case of true $A$-body scattering. The formalism is applied to loosely-bound
$^{11}$Li and $^6$He nuclei within three-body cluster models ${\rm {^9Li}}+n+n$
and $\alpha+n+n$. The $J$-matrix formalism is used not only for the calculation
of the three-body continuum spectrum wave functions but also for the
calculation of the $S$-matrix poles associated with the $^{11}$Li and $^6$He
ground states to improve the description of the binding energies and ground
state properties. The effect of the phase equivalent transformation of the
$n{-}\alpha$ interaction on the properties of the $^6$He nucleus is examined.


title:
Nucleon-nucleon interaction in the $J$-matrix inverse scattering
  approach and few-nucleon systems

abstract:
  The nucleon-nucleon interaction is constructed by means of the $J$-matrix
version of inverse scattering theory. Ambiguities of the interaction are
eliminated by postulating tridiagonal and quasi-tridiagonal forms of the
potential matrix in the oscillator basis in uncoupled and coupled waves,
respectively. The obtained interaction is very accurate in reproducing the $NN$
scattering data and deuteron properties. The interaction is used in the no-core
shell model calculations of $^3$H and $^4$He nuclei. The resulting binding
energies of $^3$H and $^4$He are very close to experimental values.


title:
The complete experiment for $e^{\mp}N$ elastic scattering in presence of
  two-photon exchange

abstract:
  We propose possible methods to measure the nucleon electromagnetic form
factors in presence of two-photon exchange. Using a general parametrization of
the spin structure of the matrix element for elastic $eN$-scattering, in terms
of three independent complex amplitudes, we show that the measurements of the
differential cross section for electron and positron nucleon elastic
scattering, in the same kinematical conditions, allows to extract the nucleon
electromagnetic form factors. The same is correct for the polarization method,
with the measurement of the $P_{x,z}$ components of the final nucleon
polarization (for the scattering of longitudinally polarized electrons and
positrons). An alternative way, in absence of positron beam, is to measure a
definite set of T-odd polarization observables, which includes three different
experiments or only T-even observables, with five independent experiments. In
both cases, the ratio $G_E(Q^2)/G_M(Q^2)$ is related to quantities of the order
of $\alpha$, which requires different polarization experiments of very high
accuracy.


title:
On the nuclear symmetry energy and the neutron skin in neutron-rich
  nuclei

abstract:
  The symmetry energy for nuclear matter and its relation to the neutron skin
in finite nuclei is discussed. The symmetry energy as a function of density
obtained in a self-consistent Green function approach is presented and compared
to the results of other recent theoretical approaches. A partial explanation of
the linear relation between the symmetry energy and the neutron skin is
proposed. The potential of several experimental methods to extract the neutron
skin is examined.


title:
Momentum dependence of the symmetry potential and nuclear reactions
  induced by neutron-rich nuclei at RIA

abstract:
  Effects of the momentum-dependence of the symmetry potential in nuclear
reactions induced by neutron-rich nuclei at RIA energies are studied using an
isospin- and momentum-dependent transport model. It is found that symmetry
potentials with and without the momentum-dependence but corresponding to the
same density-dependent symmetry energy $E_{sym}(\rho)$ lead to significantly
different predictions on several $E_{sym}(\rho)$-sensitive experimental
observables. The momentum-dependence of the symmetry potential is thus
critically important for investigating accurately the equation of state (${\rm
EOS}$) and novel properties of dense neutron-rich matter at RIA.


title:
Understanding of the freeze-out in ultra-relativistic heavy-ion
  collisions

abstract:
  I discuss the quantities and effects important for the freeze-out and outline
a formalism for the description of continuous decoupling of particles from the
fireball. Then I present a calculation of the scattering rates of pions at
various temperatures and argue that it is important to take continuous particle
decoupling into account when modelling the collision dynamics.


title:
Improved Unitarized Heavy Baryon Chiral Perturbation Theory for
  pion-nucleon Scattering to fourth order

abstract:
  We extend our previous analysis of the unitarized pion-nucleon scattering
amplitude including up to fourth order terms in Heavy Baryon Chiral
Perturbation Theory. We pay special attention to the stability of the generated
Delta(1232 resonance, the convergence problems and the power counting of the
chiral parameters.


title:
Exponential enhancement of nuclear reactions in condensed matter
  environment

abstract:
  A mechanism that uses the environment to enhance the probability of the
nuclear reaction when a beam of accelerated nuclei collides with a target
nucleus implanted in condensed matter is suggested. The effect considered is
exponentially large for low collision energies. For t + p collision the
mechanism becomes effective when the energy of the projectile tritium is below
$\sim$ 1 Kev per nucleon. The gain in probability of the nuclear reaction is
due to a redistribution of energy and momentum of the projectile in several
``preliminary'' elastic collisions with the target nucleus and the
environmental nuclei in such a way that the final inelastic projectile-target
collision takes place at a larger relative velocity, which is accompanied by a
decrease of the center of mass energy. The gain of the relative velocity
exponentially increases the penetration through the Coulomb barrier.


title: Polarization phenomena in hyperon-nucleon scattering

abstract:
  We investigate polarization observables in hyperon-nucleon scattering by
decomposing scattering amplitudes into spin-space tensors, where each component
describes scattering by corresponding spin-dependent interactions, so that
contributions of the interactions in the observables are individually
identified. In this way, for elastic scattering we find some linear
combinations of the observables sensitive to particular spin-dependent
interactions such as symmetric spin-orbit (LS) interactions and antisymmetric
LS ones. These will be useful to criticize theoretical predictions of the
interactions when the relevant observables are measured. We treat vector
analyzing powers, depolarizations, and coefficients of polarization transfers
and spin correlations, a part of which is numerically examined in $\Sigma^{+}
p$ scattering as an example. Total cross sections are studied for polarized
beams and targets as well as for unpolarized ones to investigate spin
dependence of imaginary parts of forward scattering amplitudes.


title:
Approach to Vibrational to Axially Rotational Shape Phase Transition
  Along the Yrast Line

abstract:
  With the energy surface of the nucleus in U(5) symmetry being analyzed in the
framework of thermodynamics, the vibration and rotation phase diagram in terms
of the angular momentum and deformation parameter is given. Together with
examining the energy spectrum, we propose a theoretical approach to describe
the vibrational to axially rotational phase transition along the yrast line. By
analyzing the available experimental data we show that the vibrational to
rotational shape phase transition along the yrast line takes place in many
nuclei.


title:
An aberrant "spin-orbit interaction" persists in the literature since
  more than thirty years

abstract:
  An expression for the spin-orbit interaction coupling between different
levels, which was shown to be aberrant more than thirty years ago is used in a
recent article [K. Amos, L. Canton, G.Piseni, J. P. Svenne and D. van der
Knijff, Nucl. Phys. A 728, 65 (2003)]. It leads to expressions quite simpler
than they should be. Its behavior is in fact of a character opposite to that of
the spin-orbit interaction used in two-body studies.


title: Dilepton emission rates from hot hadronic matter

abstract:
  The vacuum polarisation effects from the nucleon sector lead to large medium
modifications of the vector meson masses in the Walecka model. With a quantum
hadrodynamic framework including the quantum effects, and using a quasiparticle
description for quark gluon plasma(QGP), the dilepton emission rate from the
hot and dense matter resulting from relativistic nuclear collisions is
calculated. Using a model for the fireball evolution which has been shown to
reproduce other observables such as charmonium suppression, photon emission and
the abundance of hadronic species, we compare with the dilepton invariant mass
spectrum measured by the CERES collaboration at CERN SPS. We also compare the
results to a previous calculation where the spectral function of a virtual
photon (a key ingredient for the emission rate) has been calculated in a chiral
SU(3) model.


title:
Non-Mesonic Weak Decay of Lambda-hypernuclei: a new determination of the
  Gn/Gp ratio

abstract:
  Theoretical descriptions of the non-mesonic weak decay of Lambda-hypernuclei
are unable to reproduce the experimental values of the ratio Gn/Gp=G(Lambda n
-> nn)/G(Lambda p -> np). In this contribution we discuss a new approach to
this problem. We have incorporated a one-meson-exchange model for the Lambda N
-> nN transition in finite nuclei in an intranuclear cascade code for the
calculation of double-coincidence nucleon distributions corresponding to the
non-mesonic decay of 5_Lambda-He and 12_Lambda-C. The two-nucleon induced decay
mechanism, Lambda np -> nnp, has been taken into account within a local density
approximation scheme using a one-pion-exchange model supplemented by short
range correlations. A weak decay model independent analysis of preliminary KEK
coincidence data for 5_Lambda-He allows us to extract Gn/Gp=0.39 \pm 0.11 when
the two-nucleon induced channel is neglected (i.e., G2=0) and Gn/Gp=0.26 \pm
0.11 when G2/G1=0.2.


title: Meson Exchange Currents in (\vec{e},e'\vec{p}) observables

abstract:
  Our main aim in this work is to study the effects of meson-exchange currents
(MEC) over asymmetries and recoil polarization observables in A(e,e'p)B
reactions. This DWIA+MEC model takes care of relativistic degrees of freedom by
using semi-relativistic operators for the one-body current as well as for the
two-body MEC. These SR currents are obtained by a direct Pauli reduction of the
corresponding relativistic operators by an expansion in terms of missing
momentum over the nucleon mass, while the current dependence on the transferred
energy and momentum is treated exactly. Also some comparisons with experimental
data are made.


title: Chiral Sigma Model with Pion Mean Field in Finite Nuclei

abstract:
  The properties of infinite matter and finite nuclei are studied by using the
chiral sigma model in the framework of the relativistic mean field theory. We
reconstruct an extended chiral sigma model in which the omega meson mass is
generated dynamically by the sigma condensation in the vacuum in the same way
as the nucleon mass. All the parameters of chiral sigma model are essentially
fixed from the hadron properties in the free space. In nuclear matter, the
saturation property comes out right, but the incompressibility is too large and
the scalar and vector potentials are about a half of the phenomenological ones,
respectively. This fact is reflected to the properties of finite nuclei. We
calculate N = Z even-even mass nuclei between N = 16 and N = 34. The extended
chiral sigma model without the pion mean field leads to the result that the
magic number appears at N = 18 instead of N = 20 and the magic number does not
appear at N = 28 due to the above mentioned nuclear matter properties. The
latter problem, however, could be removed by the introduction of the finite
pion mean field with the appearance of the magic number at N = 28. We find that
the energy differences between the spin-orbit partners are reproduced by the
finite pion mean field which is completely a different mechanism from the
standard spin-orbit interaction.


title:
Realistic Calculations of Exclusive $A(e,e'p)X$ Processes off Few-Body
  Nuclei

abstract:
  The exclusive processes 2H(e,e'p)n, 3He(e,e'p)^2H, and 3He(e,e'p)(pn), have
been calculated using realistic few-body wave functions and treating final
state interaction effects within a generalized eikonal approach.


title:
Gluons, tadpoles, and color neutrality in a two-flavor color
  superconductor

abstract:
  Considering cold, dense quark matter with two massless quark flavors, we
demonstrate how, in a self-consistent calculation in the framework of QCD, the
condensation of Cooper pairs induces a non-vanishing background color field.
This background color field has precisely the right magnitude to cancel tadpole
contributions and thus ensures overall color neutrality of the two-flavor color
superconductor.


title:
Polarization of Lambda^0 hyperons as a signature for the Quark-Gluon
  Plasma

abstract:
  The momentum distribution of Lambda^0 hyperons produced from the quark-gluon
plasma (QGP) in ultra-relativistic heavy-ion collisions is calculated in
dependence on their polarization. The momentum distribution of Lambda^0
hyperons is defined by matrix elements of relativistic quark Wigner operators,
which are calculated within the Effective quark model with chiral U(3)xU(3)
symmetry and the Quark-Gluon transport theory. We show that the polarization of
the Lambda^0 hyperon depends of the spin of the strange quark that agrees well
with the DeGrand-Miettinen model. We show that Lambda^0 hyperons, produced from
the QGP, are fully unpolarized. This means that a detection of unpolarized
Lambda^0 hyperons, produced in ultra-relativistic heavy-ion collisions, should
serve as one of the signatures for the existence of the QGP in intermediate
states of ultra-relativistic heavy-ion collisions.


title: Thermodynamic properties of spherical nuclei

abstract:
  The effect of the residual interaction between the nucleons (quasiparticles)
on the thermodynamic behavior of spherical nuclei is considered. Thermodynamic
relations are derived for the simplest model of the residual interaction that
has the necessary macroscopic structure previously established. The range of
applicability of the theory is discussed.


title: An EFT for the weak $\Lambda N$ interaction

abstract:
  The nonleptonic weak $|\Delta S|=1$ $\Lambda N$ interaction, responsible for
the dominant, nonmesonic decay of all but the lightest hypernuclei, is studied
in the framework of an effective field theory. The long-range physics is
described through tree-level exchange of the SU(3) Goldstone bosons ($\pi$ and
$K$), while the short-range potential is parametrized in terms of lowest-order
contact terms obtained from the most general non-derivative local four-fermion
interaction. Fitting to available weak hypernuclear decay rates for $^5_\Lambda
{\rm He}$, $^{11}_\Lambda {\rm B}$ and $^{12}_\Lambda {\rm C}$ yields
reasonable values for the low-energy constants.


title: Strangeness dynamics in relativistic nucleus-nucleus collision

abstract:
  We investigate hadron production as well as transverse hadron spectra in
nucleus-nucleus collisions from 2 $A\cdot$GeV to 21.3 $A\cdot$TeV within two
independent transport approaches (UrQMD and HSD) that are based on quark,
diquark, string and hadronic degrees of freedom. The comparison to experimental
data demonstrates that both approaches agree quite well with each other and
with the experimental data on hadron production. The enhancement of pion
production in central Au+Au (Pb+Pb) collisions relative to scaled $pp$
collisions (the 'kink') is well described by both approaches without involving
any phase transition. However, the maximum in the $K^+/\pi^+$ ratio at 20 to 30
A$\cdot$GeV (the 'horn') is missed by $\sim$ 40%. A comparison to the
transverse mass spectra from $pp$ and C+C (or Si+Si) reactions shows the
reliability of the transport models for light systems. For central Au+Au
(Pb+Pb) collisions at bombarding energies above $\sim$ 5 A$\cdot$GeV, however,
the measured $K^{\pm}$ $m_{T}$-spectra have a larger inverse slope parameter
than expected from the calculations. The approximately constant slope of
$K^\pm$ spectra at SPS (the 'step') is not reproduced either. Thus the pressure
generated by hadronic interactions in the transport models above $\sim$ 5
A$\cdot$GeV is lower than observed in the experimental data. This finding
suggests that the additional pressure - as expected from lattice QCD
calculations at finite quark chemical potential and temperature - might be
generated by strong interactions in the early pre-hadronic/partonic phase of
central Au+Au (Pb+Pb) collisions.


title:
Dynamics of strange, charm and high momentum hadrons in relativistic
  nucleus-nucleus collisions

abstract:
  We investigate hadron production and attenuation of hadrons with strange and
charm quarks (or antiquarks) as well as high transverse momentum hadrons in
relativistic nucleus-nucleus collisions from 2 AGeV to 21.3 ATeV within two
independent transport approaches (UrQMD and HSD). Both transport models are
based on quark, diquark, string and hadronic degrees of freedom, but do not
include any explicit phase transition to a quark-gluon plasma. From our
dynamical calculations we find that both models do not describe the maximum in
the $K^+/\pi^+$ ratio at 20 - 30 AGeV in central Au+Au collisions found
experimentally, though the excitation functions of strange mesons are
reproduced well in HSD and UrQMD. Furthermore, the transport calculations show
that the charmonium recreation by $D+\bar{D} \to J/\Psi + meson$ reactions is
comparable to the dissociation by 'comoving' mesons at RHIC energies contrary
to SPS energies. This leads to the final result that the total $J/\Psi$
suppression as a function of centrality at RHIC should be less than the
suppression seen at SPS energies where the 'comover' dissociation is
substantial and the backward channels play no role. Furthermore, our transport
calculations -- in comparison to experimental data on transverse momentum
spectra from $pp$, d+Au and Au+Au reactions -- show that pre-hadronic effects
are responsible for both the hardening of the hadron spectra for low transverse
momenta (Cronin effect) as well as the suppression of high $p_T$ hadrons. The
mutual interactions of formed hadrons are found to be negligible in central
Au+Au collisions at $\sqrt{s}$ = 200 GeV for $p_T \geq$ 6 GeV/c and the
sizeable suppression seen experimentally is attributed to a large extent to the
interactions of 'leading' pre-hadrons with the dense environment.


title: Warm stellar matter with neutrino trapping

abstract:
  The properties of hybrid stars formed by hadronic and quark matter in
beta-equilibrium at fixed entropies are described by appropriate equations of
state (EOS) in the framework of relativistic mean-field theory. In this work we
include the possibility of neutrino trapped EOS and compare the star properties
with the ones obtained after deleptonization, when neutrinos have already
diffused out. We use the nonlinear Walecka model for the hadron matter with two
different sets for the hyperon couplings and the MIT Bag and the
Nambu-Jona-Lasinio models for the quark matter. The phase transition to a
deconfined quark phase is investigated. Depending on the model and the
parameter set used, the mixed phase may or may not exist in the EOS at high
densities.
  The star properties are calculated for each equation of state. The maximum
mass stellar configurations obtained within the NJL have larger masses than the
ones obtained within the Bag model. The Bag model predicts a mixed phase in the
interior of the most massive stable stars while, depending on the hyperon
couplings, the NJL model predicts a mixed phase or pure quark matter. Comparing
with neutrino free stars, the maximum allowed baryonic masses for protoneutron
stars are $\sim 0.4 M_\odot$ larger for the Bag model and $\sim 0.1 M_\odot$
larger for the NJL model when neutrino trapping is imposed.


title: In-medium effects on the $K^-/K^+$ ratio at GSI

abstract:
  The in-medium modifications on the $K^-/K^+$ ratio produced at GSI are
studied. Particular attention is paid to the properties of antikaons, which
determine the chemical potential and temperature at freeze-out conditions.
  Different approaches have been considered: non-interacting $K^-$, on-shell
self-energy and single-particle spectral density. We observe that the full
off-shell approach reproduces the "broad-band equilibration" advocated by Brown
being the spectral density crucial to explain an enhanced $K^-/K^+$ ratio.


title: Strangeness production in heavy ion reactions at intermediate energies

abstract:
  Kaon production, in particular $K^+$ production in heavy ion collisions at
intermediate energies is discussed. Main emphasis is put on the question if
subthreshold $K^+$ production can serve as a suitable tool to test the high
density phase of such reactions and to deliver information on the high density
behavior of the nuclear equation of state. It is shown that the $K^+$
excitation function in heavy ($Au+Au$) over light ($C+C$) systems provides a
robust observable which, by comparison to data, strongly favors a soft equation
of state. A second question of interest is the existence of an in-medium kaon
potential as predicted by effective chiral Lagrangiens. Here it is argued that
transport calculations support this scenario with, in the meantime, a
significant level of consistency.


title: Superconductivity with deformed Fermi surfaces and compact stars

abstract:
  I discuss the deformed Fermi surface superconductivity (DFS) and some of its
alternatives in the context of nucleonic superfluids and two flavor color
superconductors that may exist in the densest regions of compact stellar
objects.


title:
Effects of momentum-dependent symmetry potential on heavy-ion collisions
  induced by neutron-rich nuclei

abstract:
  Using an isospin- and momentum-dependent transport model we study effects of
the momentum-dependent symmetry potential on heavy-ion collisions induced by
neutron-rich nuclei. It is found that symmetry potentials with and without the
momentum-dependence but corresponding to the same density-dependent symmetry
energy $E_{sym}(\rho)$ lead to significantly different predictions on several
$E_{sym}(\rho)$-sensitive experimental observables especially for energetic
nucleons. The momentum- and density-dependence of the symmetry potential have
to be determined simultaneously in order to extract the $E_{sym}(\rho)$
accurately. The isospin asymmetry of midrapidity nucleons at high transverse
momenta is particularly sensitive to the momentum-dependence of the symmetry
potential. It is thus very useful for investigating accurately the equation of
state of dense neutron-rich matter.


title:
First order shape transition and critical point nuclei in Sm isotopes
  from relativistic mean field approach

abstract:
  The critical point nuclei in Sm isotopes, which marks the first order phase
transition between spherical U(5) and axially deformed shapes SU(3), have been
investigated in the microscopic quadrupole constrained relativistic mean field
(RMF) model plus BCS method with all the most used interactions, i.e., NL1,
NL3, NLSH and TM1. The calculated potential energy surfaces show a clear shape
transition for the even-even Sm isotopes with $N = 82\sim 96$ and the critical
point nuclei are found to be $^{148}$Sm, $^{150}$Sm and $^{152}$Sm. Similar
conclusions can also be drawn from the microscopic neutron and proton single
particle spectra.


title: The 16O(e,e'pp)14C reaction to discrete final states

abstract:
  Differential cross sections for exclusive 16O(e,e'pp)14C processes are
computed within a distorted-wave framework which includes central short-range
correlations and intermediate \Delta+ excitations. The cross sections are
compared to high-resolution data from the MAMI facility at Mainz for a central
energy and momentum transfer of \omega=215 MeV and q=316 MeV respectively. A
fair agreement between the numerical calculations and data is reached when
using spectroscopic information extracted from a 15N(d,3He)14C experiment. The
comparison between the calculations and the data provides additional evidence
that short-range correlations exclusively affect nucleon pairs with a small
center-of-mass momentum residing in a relative S state.


title: Chiral approach to nuclear matter: Role of explicit short-range NN-terms

abstract:
  We extend a recent chiral approach to nuclear matter by including the most
general (momentum-independent) NN-contact interaction. Iterating this
two-parameter contact-vertex with itself and with one-pion exchange the
emerging energy per particle exhausts all terms possible up-to-and-including
fourth order in the small momentum expansion. The equation of state of pure
neutron matter, $\bar E_n(k_n)$, can be reproduced very well up to quite high
neutron densities of $\rho_n=0.5\fmd$ by adjusting the strength of a repulsive
$nn$-contact interaction. Binding and saturation of isospin-symmetric nuclear
matter is a generic feature of our perturbative calculation. Fixing the maximum
binding energy per particle to $-\bar E(k_{f0})= 15.3 $MeV we find that any
possible equilibrium density $\rho_0$ lies below $\rho_0^{\rm max}=0.191\fmd$.
The additional constraint from the neutron matter equation of state leads
however to a somewhat too low saturation density of $\rho_0 =0.134 \fmd$. We
also investigate the effects of the NN-contact interaction on the complex
single-particle potential $U(p,k_f)+i W(p,k_f)$. We find that the effective
nucleon mass at the Fermi-surface is bounded from below by $M^*(k_{f0}) \geq
1.4 M$. This property keeps the critical temperature of the liquid-gas phase
transition at somewhat too high values $T_c \geq 21 $MeV. The downward bending
of the asymmetry energy $A(k_f)$ above nuclear matter saturation density is a
generic feature of the approximation to fourth order. Altogether, there is
within this complete fourth-order calculation no "magic" set of adjustable
short-range parameters with which one could reproduce simultaneously and
accurately all semi-empirical properties of nuclear matter.


title: Three-body spin-orbit forces from chiral two-pion exchange

abstract:
  Using chiral perturbation theory, we calculate the density-dependent
spin-orbit coupling generated by the two-pion exchange three-nucleon
interaction involving virtual $\Delta$-isobar excitation. From the
corresponding three-loop Hartree and Fock diagrams we obtain an isoscalar
spin-orbit strength $F_{\rm so}(k_f)$ which amounts at nuclear matter
saturation density to about half of the empirical value of $90 $MeVfm$^5$. The
associated isovector spin-orbit strength $G_{\rm so}(k_f)$ comes out about a
factor of 20 smaller. Interestingly, this three-body spin-orbit coupling is not
a relativistic effect but independent of the nucleon mass $M$. Furthermore, we
calculate the three-body spin-orbit coupling generated by two-pion exchange on
the basis of the most general chiral $\pi\pi NN$-contact interaction. We find
similar (numerical) results for the isoscalar and isovector spin-orbit
strengths $F_{\rm so}(k_f)$ and $G_{\rm so}(k_f)$ with a strong dominance of
the p-wave part of the $\pi\pi NN$-contact interaction and the Hartree
contribution.


title:
Nuclear energy density functional from chiral pion-nucleon dynamics:
  Isovector spin-orbit terms

abstract:
  We extend a recent calculation of the nuclear energy density functional in
the systematic framework of chiral perturbation theory by computing the
isovector spin-orbit terms: $(\vec \nabla \rho_p- \vec \nabla \rho_n)\cdot(\vec
J_p-\vec J_n) G_{so}(k_f)+ (\vec J_p-\vec J_n)^2 G_J(k_f)$. The calculation
includes the one-pion exchange Fock diagram and the iterated one-pion exchange
Hartree and Fock diagrams. From these few leading order contributions in the
small momentum expansion one obtains already a good equation of state of
isospin-symmetric nuclear matter. We find that the parameterfree results for
the (density-dependent) strength functions $G_{so}(k_f)$ and $G_J(k_f)$ agree
fairly well with that of phenomenological Skyrme forces for densities $\rho >
\rho_0/10$. At very low densities a strong variation of the strength functions
$G_{so}(k_f)$ and $G_J(k_f)$ with density sets in. This has to do with chiral
singularities $m_\pi^{-1}$ and the presence of two competing small mass scales
$k_f$ and $m_\pi$. The novel density dependencies of $G_{so}(k_f)$ and
$G_J(k_f)$ as predicted by our parameterfree (leading order) calculation should
be examined in nuclear structure calculations.


title: Iterated and irreducible pion-photon exchange in nuclei

abstract:
  We calculate the contribution to the nuclear energy density functional which
arises from iterated pion-photon exchange between nucleons. In heavy nuclei,
this novel charge symmetry breaking interaction leads to an additional binding
of each proton by about 0.2 MeV. Compared to that the analogous effect from
irreducible pion-photon exchange is negligibly small. As a possible mechanism
to resolve the Nolen-Schiffer anomaly we propose the iteration of one-photon
exchange with an attractive short-range NN-interaction. The corresponding
energy per proton reads: $\bar E[\rho_p]=(2\alpha/15\pi^2)(\pi^2 -3+6 \ln2)
{\cal A}_{pp} k_p^2$ with $\rho_p =k_p^3/ 3\pi^2$ the proton density and ${\cal
A}_{pp}\approx 2 $fm an effective (in-medium) scattering length. Hints for such
a value of ${\cal A}_{pp}$ come from phenomenological Skyrme forces and from
the neutron matter equation of state.


title: Pion Charge Exchange on Deuterium

abstract:
  We investigate quantum corrections to a classical intranuclear cascade
simulation of pion single charge exchange on the deuteron. In order to separate
various effects the orders of scattering need to be distinguished and, to that
end, we develop signals for each order of scattering corresponding to
quasi-free conditions. Quantum corrections are evaluated for double scattering
and are found to be large. Global agreement with the data is good.


title: Overtones of Isoscalar Giant Resonances in medium-heavy and heavy nuclei

abstract:
  A semi-microscopic approach based on both the
continum-random-phase-approximation (CRPA) method and a phenomenological
treatment of the spreading effect is extended and applied to describe the main
properties (particle-hole strength distribution, energy-dependent transition
density, partial direct-nucleon-decay branching ratios) of the isoscalar giant
dipole, second monopole, and second quadrupole resonances. Abilities of the
approach are checked by description of gross properties of the main-tone
resonances. Calculation results obtained for the resonances in a few singly-
and doubly-closed-shell nuclei are compared with available experimental data.


title:
Nuclear Forces and Few-Nucleon Studies Based on Chiral Perturbation
  Theory

abstract:
  After a brief review on the status of few--nucleon studies based on
conventional nuclear forces, we sketch the concepts of the effective field
theory approach constrained by chiral symmetry and its application to nuclear
forces. Then first results for few--nucleon observables are discussed.


title: Symmetry energy coefficients for asymmetric nuclear matter

abstract:
  Symmetry energy coefficients of asymmetric nuclear matter are investigated as
the inverse of nuclear matter polarizabilities with two different approaches.
Firstly a general calculation shows they may depend on the neutron-proton
asymmetry itself. The choice of particular prescriptions for the density
fluctuations lead to certain isospin (n-p asymmetry) dependences of the
polarizabilities. Secondly, with Skyrme type interactions, the static limit of
the dynamical polarizability is investigated corresponding to the inverse
symmetry energy coefficient which assumes different values at different
asymmetries (and densities and temperatures). The symmetry energy coefficient
(in the isovector channel) is found to increase as n-p asymmetries increase.
The spin symmetry energy coefficient is also briefly investigated.


title:
Transverse radial expansion in nuclear collisions and two particle
  correlations

abstract:
  At the very first stage of an ultra-relativistic nucleus-nucleus collision
new particles are produced in individual nucleon-nucleon collisions. In the
transverse plane, all particles from a single $NN$ collision are initially
located at the same position. The subsequent thermalization and transverse
radial expansion of the system create strong position-momentum correlations and
lead to characteristic rapidity, transverse momentum, and azimuthal
correlations among the produced particles.


title:
Sensitivity of exclusive proton knockout spin observables to different
  Lorentz invariant representations of the NN interaction

abstract:
  Within the framework of the relativistic plane wave impulse approximation, we
study the observable consequences of employing a complete Lorentz invariant
representation of the NN scattering matrix in terms of 44 independent
amplitudes, as opposed to the previously-employed, but ambiguous, five-term
Lorentz invariant parametrization of the NN scattering matrix, for the
prediction of complete sets of exclusive ($\vec{p},2 \vec{p} $) polarization
transfer observables. Two kinematic conditions are considered, namely proton
knockout from the $3s_{1/2}$ state of $^{208}$Pb at an incident energy of 202
MeV for coplanar scattering angles ($28.0^{\circ}, -54.6^{\circ}$), as well as
an incident energy of 392 MeV for the angle pair ($32.5^{\circ},
-80.0^{\circ}$). The results indicate that certain spin observables are ideal
for discriminating between the two representations.


title:
Structural Studies of Many-Body Systems and (e,e'p) Reaction Cross
  Sections

abstract:
  Studies of one-body density matrices (ODM) are performed in various
correlation methods, such as the Jastrow method, the correlated basis function
method, the Green's function method and the generator coordinate method aiming
to extract the absolute spectroscopic factors and overlap functions (OF) for
one-nucleon removal reactions from the ODM of the target nucleus. The advantage
of this method is that it avoids the complicated task of calculating the total
nuclear spectral function. The procedure for extracting bound-state OF's has
been applied to make calculations of the cross sections of the
$(e,e^{\prime}p)$ reaction on the closed-shell nuclei $^{16}$O and $^{40}$Ca as
well as on the open-shell nucleus $^{32}$S consistently (using the same OF's)
with the cross sections of $(p,d)$ and $(\gamma,p)$ reactions on the same
nuclei. The analyses of the reaction cross sections and the spectroscopic
factors and the comparison with the experimental data show the particular
importance of these OF's, since they contain effects of nucleon correlations
(short-range and/or long-range) which are accounted for to different extent in
the theoretical methods considered.


title:
The relation between the photonuclear E1 sum rule and the effective
  orbital g-factor

abstract:
  The connection between the enhancement factor (1+kappa) of the photonuclear
E1 sum rule and the orbital angular momentum g-factor (gl) of a bound nucleon
is investigated in the framework of the Landau-Migdal theory for isospin
asymmetric nuclear matter. Special emphasis is put on the role of gauge
invariance to establish the kappa-gl relation. By identifying the physical
processes which are taken into account in kappa and gl, the validity and
limitations of this relation are discussed. The connections to the collective
excitations and to nuclear Compton scattering are also shown.


title:
Centrality dependence of high $p_T$ suppression in Au+Au collisions
  suggest quark matter formation

abstract:
  In a pQCD-based model, we have analyzed the STAR data on the high $p_T$
suppression of charged hadrons, in Au+Au collisions at $\sqrt{s}$=200 GeV. In
the jet quenching or the energy loss picture, $p_T$ spectra of charged hadrons
as well as the $p_T$ dependence of nuclear modification factor, in all the
centrality ranges, are well explained, with nearly a constant relative energy
loss, $\Delta E/E=0.56\pm 0.03$. Centrality independence of relative energy
loss indicate that the matter produced in central and in peripheral collisions
are different, otherwise relative energy loss would have shown strong
centrality dependence. Qualitatively, centrality independence of relative
energy loss can be understood, if in central Au+Au collisions deconfined matter
is produced and the matter remain confined in peripheral collisions.


title: Solving the Richardson equations for Fermions

abstract:
  Forty years ago Richardson showed that the eigenstates of the pairing
Hamiltonian with constant interaction strength can be calculated by solving a
set of non-linear coupled equations. However, in the case of Fermions these
equations lead to singularities which made them very hard to solve. This letter
explains how these singularities can be avoided through a change of variables
making the Fermionic pairing problem numerically solvable for arbitrary single
particle energies and degeneracies.


title: Lambda-Lambda hypernuclei and stranger systems

abstract:
  Recent experiments on production of Lambda-Lambda hypernuclei have renewed
interest in extracting the Lambda-Lambda interaction from the few events
identified since the inception of this field forty years ago. Few-body
calculations relating to this issue are reviewed, particularly with respect to
the possibility that A=4 marks the onset of Lambda-Lambda binding in nuclei.
The Nijmegen soft-core model potentials NSC97 qualitatively agree with the
strength of the Lambda-Lambda interaction deduced from the newly determined
binding energy of Lambda-Lambda-6He. Applying the extended NSC97 model to
stranger nuclear systems suggests that A=6 marks the onset of Xi binding, with
a particle stable Lambda-Xi-6He, and that strange hadronic matter is robustly
bound.


title: Shape-Invariance and Many-Body Physics

abstract:
  Recent developments in the study of shape-invariant Hamiltonians are briefly
summarized. Relations between certain exactly solvable problems in many-body
physics and shape-invariance are explored. Connection between Gaudin algebras
and supersymmetric quantum mechanics is pointed out.


title: Predictions from Microscopic Models on Particle Correlations at RHIC

abstract:
  We review the recent developments on microscopic transport calculations for
two-particle correlations at low relative momenta in ultrarelativistic heavy
ion collisions at RHIC.


title:
Structure of the nucleon from electromagnetic space-like and time-like
  form factors

abstract:
  Recent experimental data on space-like and time-like form factors of the
nucleon are reviewed in light of a model of the nucleon with an intrinsic
(quark-like) structure and a meson cloud. The analysis points to the
astonishing result that the proton electric space-like form factor vanishes at
Q^2~8 (GeV/c)^2 and becomes negative beyond that point. The intrinsic structure
is estimated to have a r.m.s. radius of ~0.34 fm, much smaller than the proton
r.m.s. radius ~0.82 fm. The calculations are in perfect agreement with
space-like proton data, but deviate drastically from space-like neutron data at
Q^2>1 (GeV/c)^2. Analysis of the time-like data appears to indicate excellent
agreement with both proton and neutron data in the entire range of measured
q^2=-Q^2 values.


title:
Investigating the parity of the exotic Theta^+ baryon from the kaon
  photoproduction

abstract:
  Based on the hadronic model with the gauge prescription suggested by Ohta and
Haberzettl, we investigate the possibility of determining the parity state of
the $\Theta^+$ baryon using photon induced processes, $\gamma n\to K^-
\Theta^+$ and $\gamma p\to \bar{K}^0 \Theta^+$. The total and differential
cross sections are simulated in two versions of pseudovector(PV) and
pseudoscalar(PS) coupling schemes and the results are reported both on the
positive and negative parity states of the $\Theta^+$ baryon. It is found that
in both coupling schemes the total cross sections from the neutron target are
in general larger than those from the proton target, regardless of the
$\Theta^+$ parities. The cross sections of the $\Theta^+$ production however
depend largely on the value of the $\Theta^+$ decay width which is not yet well
established. Moreover, there is a wide theoretical uncertainty associated with
the different assumption on the gauge prescription in model calculations. We
discuss these points by comparing theoretical predictions with the existing
experimental data. Our analysis suggests that the observation of the angular
distribution rather than just the total cross section in the photoproduction
process may be a useful tool to distinguish the parity of the $\Theta^+$
baryon.


title: A$(\vec{e},e'\vec{p})$B responses: from bare nucleons to complex nuclei

abstract:
  We study the occurrence of factorization in polarized and unpolarized
observables in coincidence quasi-elastic electron scattering. Starting with the
relativistic distorted wave impulse approximation, we reformulate the effective
momentum approximation and show that the latter leads to observables which
factorize under some specific conditions. Within this framework, the role
played by final state interactions and, in particular, by the spin-orbit term
is explored. Connection with the nonrelativistic formalism is studied in depth.
Numerical results are presented to illustrate the analytical derivations and to
quantify the differences between factorized and unfactorized approaches.


title: Counting pairs in $^{44}$Ti with various interactions

abstract:
  We count the number of pairs in the single $j-$shell model of $^{44}$Ti for
various interactions. For a state of total angular momentum $I$, the wave
function can be written as $\Psi=\sum_{J_P J_N} D(J_P J_N)
[(j^2)_{J_P}(j^2)_{J_N}]_I$, where $D(J_P J_N)$ is the probability amplitude
that the protons couple to $J_P$ and the neutrons to $J_N$. For I=0 there are
three states with ($I=0, T=0$) and one with ($I=0, T=2$). The latter is the
double analog of $^{44}$Ca. In that case (T=2), the magnitude of $D(JJ)$ is the
same as that of a corresponding two particle fractional parentage coefficient.
In counting the number of pairs with an even angular momentum $J_A$ we find a
new relationship obtained by diagonalizing a unitary nine-j symbol. We are also
able to get results for the 'no-interaction' case for T=0 states, for which it
is found that there are less ($J=1, T=0$) pairs than on the average. Relative
to this 'no-interaction case' we find for the most realistic interaction used
that there is an enhancement of pairs with angular momentum $J_A=0,2,1$ and 7,
and a depletion for the others. Also considered are interactions in which only
the ($J=0, T=1$) pair state is at lower energy, only the ($J=1, T=0$) pair
state is lowered and where both are equally lowered.


title: Quark mass effects on the stability of hybrid stars

abstract:
  We perform a study of the possible existence of hybrid stars with color
superconducting quark cores using a specific hadronic model in a combination
with an NJL-type quark model. It is shown that the constituent mass of the
non-strange quarks in vacuum is a very important parameter that controls the
beginning of the hadron-quark phase transition. At relatively small values of
the mass, the first quark phase that appears is the two-flavor color
superconducting (2SC) phase which, at larger densities, is replaced by the
color-flavor locked (CFL) phase. At large values of the mass, on the other
hand, the phase transition goes from the hadronic phase directly into the CFL
phase avoiding the 2SC phase. It appears, however, that the only stable hybrid
stars obtained are those with the 2SC quark cores.


title: Collective clusterization effects in light heavy ion reactions

abstract:
  The collective clusterization process, proposed for intermediate mass
fragments (IMFs, 4$<$A$\le$28, 2$<$Z$\le$14) emitted from the hot and rotating
compound nuclei formed in low energy reactions, is extended further to include
also the emission of light particles (LPs, A$\le$4, Z$\le$2) from the
fusion-evaporation residues. Both the LPs and IMFs are treated as the dynamical
collective mass motion of preformed clusters through the barrier. Compared to
IMFs, LPs are shown to have different characteristics, and the predictions of
our, so-called, dynamical cluster-decay model are similar to those of the
statistical fission model.


title:
New analytic solutions of the collective Bohr hamiltonian for a
  beta-soft, gamma-soft axial rotor

abstract:
  New analytic solutions of the quadrupole collective Bohr hamiltonian are
proposed, exploiting an approximate separation of the beta and gamma variables
to describe gamma-soft prolate axial rotors. The model potential is a sum of
two terms: a beta-dependent term taken either with a Coulomb-like or a
Kratzer-like form, and a gamma-dependent term taken as an harmonic oscillator.
In particular it is possible to give a one parameter paradigm for a beta-soft,
gamma-soft axial rotor that can be applied, with a considerable agreement, to
the spectrum of 234U.


title:
Elliptic flow of resonances at RHIC: probing final state interactions
  and the structure of resonances

abstract:
  We propose the measurement of the elliptic flow of hadron resonances at the
Relativistic Heavy Ion Collider as a tool to probe the amount of hadronic final
state interactions for resonances at intermediate and large transverse momenta.
This can be achieved by looking at systematic deviations of the measured flow
coefficient $v_2$ from the scaling law given by the quark recombination
formalism. Our method can be generalized to explore the structure of exotic
particles, such as the recently found pentaquark $\Theta^+ (1540)$.


title: Collisional Effects on HFS Transitions of Antiprotonic Helium

abstract:
  Collisions of metastable antiprotonic helium with medium atoms induce
transitions between hyperfine structure sublevels as well as shift and
broadening of the microwave M1 spectral lines. We consider these effects in the
framework of a simple model with scalar and tensor interactions between
$(\bar{p}\mathrm{He}^+)_{nL}$ and $\mathrm{He}$ atoms. $S$-matrix is obtained
by solving coupled-channels equations involving 4 HFS sublevels $(F=L\pm 1/2,
J=F\pm 1/2)$ of the $nL$ level and relative angular momenta up to $l=5$ at the
kinetic energy $E\lesssim 10$ K. The calculated spin-flip cross sections are
less than elastic ones by 4 orders of value. At the density $N=3\times 10^{20}$
cm$^{-3}$ and T=6 K we obtain the relaxation times $\tau(FJ\to F'J')\gtrsim
160$ ns, the frequency shifts of M1 spectral lines $\Delta\nu\lesssim 66$ KHz
for the favored transitions ($\Delta F=\pm 1, \Delta J=\pm 1$) and frequency
broadening of the M1 spectral lines $\gamma/2\lesssim 5.8$ MHz. The results are
compatible with the recent experimental data obtained by a
laser-microwave-laser resonance method.


title:
Analyses of two and three pion Bose-Einstein Correlations using Coulomb
  wave functions

abstract:
  Using effective formulas we analyze the Bose-Einstein correlations (BEC) data
corrected for Coulomb interactions provided by STAR Collaboration and the
quasi-corrected data (raw data with acceptance correction etc) on 2\pi and 3\pi
BEC by using Coulomb wave function with coherence parameter included. The
corresponding magnitudes of the interaction regions turn out to be almost the
same: R_{Coul}(2\pi) \simeq \frac 32R_{Coul}(3\pi). R_{Coul} means the size of
interaction region obtained in terms of Coulomb wave function. This approximate
relation is also confirmed by the core-halo model. Moreover, the genuine 3rd
order term of BEC has also been investigated in this framework and its
magnitude has been estimated both in the fully corrected data and in the
quasi-corrected data.


title: A self-consistent QRPA study of quadrupole collectivity around 32Mg

abstract:
  On the basis of the Hartree-Fock-Bogoliubov (HFB) plus quasiparticle random
phase approximation method (QRPA) based on the Green's function approach with
Skyrme force, we discuss the anomalous E2 properties of the first 2+ states in
neutron-rich nuclei 32Mg and 30Ne. The B(E2) values and the excitation energies
of the first 2+ states are well described within HFB plus QRPA calculations
with spherical symmetry. We conclude that pairing effects account largely for
the anomalously large B(E2) values and the low excitation energies in 32Mg and
30Ne.


title:
News on Strangeness at Ultrarelativistic Energies - Review of
  Microscopic Models

abstract:
  We review recent developments in the field of microscopic transport model
calculations for ultrarelativistic heavy ion collisions. In particular, we
focus on the strangeness production, for example, the phi-meson and its role as
a messenger of the early phase of the system evolution. Moreover, we discuss
the important effects of the (soft) field properties on the multiparticle
system. We outline some current problems of the models as well as possible
solutions to them.


title: Three-body structure of the low-lying $^{17}$Ne-states

abstract:
  The Borromean nucleus $^{17}$Ne ($^{15}$O$ + p + p$) is investigated by using
the hyperspheric adiabatic expansion for a a three-body system. The measured
size of $^{15}$O and the low-lying resonances of $^{16}$F ($^{15}$O$ + p$) are
first used as constraints to determine both central and spin-dependent two-body
interactions. Then, the ground state structure of $^{17}$Ne is found to be an
almost equal mixture of $s^2$ and $d^2$ proton-$^{15}$O relative states, the
two lowest excited states have about 80% of $sd$-mixed components, and for the
next two excited three-body states the proton-$^{15}$O relative s-states do not
contribute. The spatial extension is as in ordinary nuclei. The widths of the
resonances are estimated by the WKB transmission through the adiabatic
potentials and found in agreement with the established experimental limits. We
compare with experimental information and previous works.


title: Subthreshold antiproton production in proton-carbon reactions

abstract:
  Data from KEK on subthreshold antiproton as well as on pi(+-) and K(+-)
production in proton-nucleus reactions are described at projectile energies
between 3.5 and 12.0 GeV. We use a model which considers a hadron-nucleus
reaction as an incoherent sum over collisions of the projectile with a varying
number of target nucleons. It samples complete events and allows thus for the
simultaneous consideration of all particle species measured. The overall
reproduction of the data is quite satisfactory. It is shown that the
contributions from the interaction of the projectile with groups of several
target nucleons are decisive for the description of subthreshold production.
Since the collective features of subthreshold production become especially
significant far below the threshold, the results are extrapolated down to COSY
energies. It is concluded that an antiproton measurement at ANKE-COSY should be
feasible, if the high background of other particles can be efficiently
suppressed.


title: Continuum Response and Reaction in Neutron-Rich Be Nuclei

abstract:
  We study E1 resonances, breakup and fusion reactions for weakly bound Be
nuclei. The absorbing-boundary condition (ABC) is used to describe both the
outgoing and incoming boundary conditions. The neutron continuum plays
important roles in response and reaction of neutron drip-line nuclei.


title: Response in the continuum for light deformed neutron-rich nuclei

abstract:
  The time-dependent Hartree-Fock calculation with a full Skyrme energy
functional has been carried out on the three-dimensional Cartesian lattice
space to study E1 giant dipole resonances (GDR) in light nuclei. The outgoing
boundary condition for the continuum states is treated by the absorbing complex
potential. The calculation for GDR in O-16 suggests a significant influence of
the residual interaction associated with time-odd densities in the Skyrme
functional. We also predict a large damping for superdeformed Be-14 at the
neutron drip line.


title: Meson-Meson Interactions and Resonances in the 't Hooft Model

abstract:
  We studied meson-meson interactions using the 't Hooft model, which
represents QCD in 1+1 dimensions and assumes a large number of colors ($N_c$).
The dominant interactions in this large $N_c$ limit are generated by quark
exchange. Our results show that QCD in 1+1 dimensions allows the realization of
a constituent-type quark model for the mesons, and generates a scalar
``$\sigma$''-like meson-meson resonance, whose effective coupling and mass are
determined by the underlying QCD dynamics. These results suggest an
interpretation of the lightest scalar mesons as $q\bar{q} q \bar{q}$ systems.


title:
Color Superconducting Gap in Schwinger-Dyson Equation and Nonlocal Gauge
  Fixing

abstract:
  We solve Schwinger-Dyson (SD) equation for the color superconducting (CS) gap
in nonlocal gauge which justifies the ladder approximation in subleading order
calculation. The gap prefactor increases about 1.6 times to the leading order
gap determined in Landau gauge.


title: Case of Almost Redundant Components in 3 alpha Faddeev Equations

abstract:
  The 3 alpha orthogonality condition model using the Pauli-forbidden bound
states of the Buck, Friedlich and Wheatly alpha alpha potential can yield a
compact 3 alpha ground state with a large binding energy, in which a small
admixture of the redundant components can never be eliminated.


title: In-medium Properties of Hadrons -- Observables

abstract:
  We first briefly review the theoretical basis for calculations of changes of
hadronic properties in dense nuclear matter. These changes have usually been
investigated by means of relativistic heavy-ion reactions. Here we discuss that
observable consequences of such changes can also be seen in more elementary
reactions on nuclei. Particular emphasis is put on a discussion of actual
observables in photonuclear reactions; we discuss in detail $\eta$- and
vector-meson production. We show that photoproduction of $\eta$'s can yield
essential information on in-medium properties of the $S_{11}(1535)$ resonance
while the $\phi$ meson properties will probably not be accessible through the
$K^+K^-$ decay channel. However, for $\omega$ mesons the $\pi^0\gamma$ decay
channel, due to its reduced final state interaction, looks more promising in
this respect. Completely free of final state interactions is dilepton
production in the few GeV range. We show that the sensitivity of this decay
channel to changes of hadronic properties in medium in photonuclear reactions
on nuclei is as large as in ultrarelativistic heavy ion collisions. Finally we
discuss that hadron production in nuclei at 10 -- 20 GeV photon energies can
give important information on the hadronization process.


title: Deuteron Distribution in Nuclei and in Correlated Nuclear Matter

abstract:
  We compute the distribution of quasideuterons in doubly closed shell nuclei
and infinite correlated nuclear matter. The ground states of $^{16}$O and
$^{40}$Ca are described in $ls$ coupling using a realistic hamiltonian
including the Argonne $v_{8}^\prime$ and the Urbana IX models of two-- and
three--nucleon potentials, respectively. The nuclear wave function contains
central and tensor correlations, and correlated basis functions theory is used
to evaluate the distribution of neutron-proton pairs, having the deuteron
quantum numbers, as a function of their total momentum. By computing the number
of deuteron--like pairs we are able to extract the Levinger's factor and
compare to both the available experimental data and the predictions of the
local density approximation, based on nuclear matter estimates. The agreement
with the experiments is excellent, whereas the local density approximation is
shown to sizably overestimate the Levinger's factor in the region of the medium
nuclei.


title: Dirac Sea Contribution in Relativistic Random Phase Approximation

abstract:
  In the hadrodynamics (QHD) there are two methods to take account of the
contribution of negative-energy states in the relativistic random phase
approximation (RRPA). Dawson and Furnstahl made the ansatz that the Dirac sea
were empty, while according to the Dirac hole theory the sea should be fully
occupied. The two methods seem contradictory. Their close relationship and
compatibility are explored and in particular the question of the ground-state
(GS) instability resulting from Dawson-Furnstanhl's ansatz is discussed.


title: Nuclear Structure - "ab initio"

abstract:
  An ab-initio description of atomic nuclei that solves the nuclear many-body
problem for realistic nuclear forces is expected to possess a high degree of
predictive power. In this contribution we treat the main obstacle, namely the
short-ranged repulsive and tensor correlations induced by the realistic
nucleon-nucleon interaction, by means of a unitary correlation operator. This
correlator applied to uncorrelated many-body states imprints short-ranged
correlations that cannot be described by product states. When applied to an
observable it induces the correlations into the operator, creating for example
a correlated Hamiltonian suited for Slater determinants. Adding to the
correlated realistic interaction a correction for three-body effects,
consisting of a momentum-dependent central and spin-orbit two-body potential we
obtain an effective interaction that is successfully used for all nuclei up to
mass 60. Various results are shown.


title: Quark distributions in nuclear matter and the EMC effect

abstract:
  Quark light cone momentum distributions in nuclear matter and the structure
function of a bound nucleon are investigated in the framework of the
Nambu-Jona-Lasinio model. This framework describes the nucleon as a
relativistic quark-diquark state, and the nuclear matter equation of state by
using the mean field approximation. The scalar and vector mean fields in the
nuclear medium couple to the quarks in the nucleon and their effect on the spin
independent nuclear structure function is investigated in detail. Special
emphasis is placed on the important effect of the vector mean field and on a
formulation which guarantees the validity of the number and momentum sum rules
from the outset.


title:
Density and temperature dependence of nucleon-nucleon elastic cross
  section

abstract:
  The in-medium neutron-proton, proton-proton (neutron-neutron) elastic
scattering cross sections ($\sigma_{np}^{*}$, $\sigma_{pp(nn)}^{*}$) are
studied based on the effective Lagrangian of density dependent relativistic
hadron theory in which the $\delta$[$a_0(980)$] meson is included. Our study
shows that at low densities the $\sigma_{np}^*$ is about 3-4 times larger than
$\sigma_{pp(nn)}^*$ and at densities higher than the normal density the isospin
effect is almost washed out. Because of coupling to $\delta$ meson the
$\sigma_{nn}^*$ and $\sigma_{pp}^*$ are different in isospin asymmetric medium
following the splitting of the proton and neutron mass. The isospin effect on
the density dependence of the in-medium nucleon elastic cross section is
dominantly contributed by the isovector $\delta$ and $\rho$ mesons. The
temperature effect on the $\sigma_{np}^*$ and $\sigma_{pp(nn)}^*$ is studied.
It is shown that the temperature effect is weaker compared with the density
effect but it becomes obvious as density increases.


title:
Re-visit the N/Z ratio of free nucleons from collisions of neutron -rich
  nuclei as a probe of EoS of asymmetric nuclear matter

abstract:
  The N/Z ratio of free nucleons from collisions of neutron-rich nuclei as a
function of their momentum is studied by means of Isospin dependent Quantum
Molecular Dynamics.
  We find that this ratio is not only sensitive to the form of the density
dependence of the symmetry potential energy but also its strength determined by
the symmetry energy coefficient.
  The uncertainties about the symmetry energy coefficient influence the
accuracy of probing the density dependence of the symmetry energy by means of
the N/Z ratio of free nucleons of neutron-rich nuclei.


title:
Quark Coalescence for Charmed Mesons in Ultrarelativistic Heavy-Ion
  Collisions

abstract:
  We investigate effects of charm-quark interactions in a Quark-Gluon Plasma on
the production of $D$ and $J/\psi$ mesons in high-energy heavy-ion collisions.
Employing a previously constructed coalescence model that successfully
reproduces the transverse momentum ($p_T$) spectra and elliptic flow
($v_2(p_T)$) of light hadrons at RHIC from underlying light-quark distributions
at the phase transition temperature $T_c$, $D$-meson and $J/\psi$ $p_T$ spectra
are evaluated. For the charm-quark distributions, we consider two limiting
scenarios: (i) {\em no} rescattering, corresponding to perturbative QCD spectra
and (ii) {\em complete} thermalization including transverse expansion. With the
$D$-meson spectra acquiring a minimal $v_2$ inherited from their light-quark
content, the corresponding semileptonic decay spectra of single electrons are
found to practically preserve the $v_2$ of the parent particles, exhibiting
marked differences between the pQCD and thermal scenarios for $p_T\ge 1$ GeV.
Likewise, the $p_T$-spectra and yields of $J/\psi$'s differ appreciably in the
two scenarios.


title: Breakup of 8B and the S17 astrophysical factor revisited

abstract:
  Existing experimental data for the breakup of 8B at energies from 30 to 1000
MeV/nucleon on light through heavy targets are analyzed in detail in terms of
an extended Glauber model. The predictions of the model are in excellent
agreement with independent reaction data (reaction cross sections and parallel
momentum distributions for core like fragments). Final state interactions have
been included in the Coulomb dissociation component. We extract asymptotic
normalization coefficients (ANC) from which the strophysical factor S17(0) for
the key reaction for solar neutrino production, 7Be(p,gamma)8B, can be
evaluated. Glauber model calculations using different effective interactions
give consistent, though slightly different results. The differences give a
measure of the precision one can expect from the method. The unweighted average
of all ANCs extracted leads to S17(0)=18.7+/-1.9 eVb. The results of this new
analysis are compared with the earlier one. They are consistent with the values
from most direct measurements and other indirect methods.


title: Inelastic interactions between nuclei at high energies

abstract:
  A theory of nucleus-nucleus collisions has been developed for kinetic
energies substantially in excess of the binding energy. The very high pressure
produced in the compound system as a result of the fusion of the two colliding
nuclei is the reason for the subsequent hydrodynamic expansion of the nuclear
medium. The energy and angular distributions of the reaction products are
investigated. The charge distribution is also determined in the case where the
nucleon and ion components of the reaction products are predominant. A solution
is found for the expansion into vacuum of a sphere in which the initially
uniformly distributed material is initially at rest and at an ultrarelativistic
temperature.


title:
A Genetic Algorithm Analysis of N* Resonances in
  $p(\gamma,K^{+})\Lambda$ Reactions

abstract:
  The problem of extracting information on new and known $N^{*}$ resonances by
fitting isobar models to photonuclear data is addressed. A new fitting
strategy, incorporating a genetic algorithm, is outlined. As an example, the
method is applied to a typical tree-level analysis of published
$p(\gamma,K^{+})\Lambda$ data. It is shown that, within the limitations of this
tree-level analysis, a resonance in addition to the known set is required to
obtain a reasonable fit. An additional $P_{11}$ resonance, with a mass of about
1.9 GeV, gives the best agreement with the published data, but additional
$S_{11}$ or $D_{13}$ resonances cannot be ruled out. Our genetic algorithm
method predicts that photon beam asymmetry and double polarization
$p(\gamma,K^{+})\Lambda$ measurements should provide the most sensitive
information with respect to missing resonances.


title:
The Adler-Weisberger and Goldberger-Miyazawa-Oehme sum rules as probes
  of constraints from analyticity and chiral symmetry in dynamical models for
  pion-nucleon scattering

abstract:
  The Adler-Weisberger and Goldberger-Miyazawa-Oehme sum rules are calculated
within a relativistic, unitary and crossing symmetric dynamical model for
pion-nucleon scattering using two different methods: 1) by evaluating the
scattering amplitude at the corresponding low-energy kinematics and 2) by
evaluating the sum-rule integrals with the calculated total cross section. The
discrepancy between the results of the two methods provides a measure of the
breaking of analyticity and chiral symmetry in the model. The contribution of
the $\Delta$ resonance, including its dressing with meson loops, is discussed
in some detail and found to be small.


title: Non-extensive resonant reaction rates in astrophysical plasmas

abstract:
  We study two different physical scenarios of thermonuclear reactions in
stellar plasmas proceeding through a narrow resonance at low energy or through
the low energy wing of a wide resonance at high energy. Correspondingly, we
derive two approximate analytical formulae in order to calculate thermonuclear
resonant reaction rates inside very coupled and non ideal astrophysical plasmas
in which non-extensive effects are likely to arise. Our results are presented
as simple first order corrective factors that generalize the well known
classical rates obtained in the framework of Maxwell-Boltzmann statistical
mechanics. As a possible application of our results, we calculate the
dependence of the total corrective factor with respect to the energy at which
the resonance is located, in an extremely dense and non ideal carbon plasma.


title:
Temperature dependence of modified CNO nuclear reaction rates in dense
  stellar plasmas

abstract:
  We study the dependence of the CNO nuclear reaction rates on temperature, in
the range of $10^7\div 10^8$ K, the typical range of temperature evolution from
a Sun-like star towards a white dwarf. We show that the temperature dependence
of the CNO nuclear reaction rates is strongly affected by the presence of
non-extensive statistical effects in the dense stellar core. A very small
deviation from the Maxwell-Boltzmann particle distribution implies a relevant
enhancement of the CNO reaction rate and could explain the presence of heavier
elements (e.g. Fe, Mg) in the final composition of a white dwarf core. Such a
behavior is consistent with the recent experimental upper limit to the fraction
of energy that the Sun produces via the CNO fusion cycle.


title:
Shell structures in oxygen isotopes described with modern
  nucleon-nucleon interactions

abstract:
  Shell structures in the N\simeq Z nucleus ^{17}O and the neutron-rich oxygen
isotopes ^{23}O and ^{25}O are microscopically described by calculating
single-particle energies with modern nucleon-nucleon interactions within the
framework of the unitary-model-operator approach. It is found that the effect
of three-body cluster terms on the single-particle energy is more important in
^{23}O and ^{25}O than ^{17}O.


title:
Nonextensive statistical effects on the relativistic nuclear equation of
  state

abstract:
  Following the basic prescriptions of the Tsallis' nonextensive
thermodynamics, we study the relativistic nonextensive thermodynamics and the
equation of state for a perfect gas at the equilibrium. The obtained results
are used to study the relativistic nuclear equation of state in the hadronic
and in the quark-gluon plasma phase. We show that small deviations from the
standard extensive statistics imply remarkable effects into the shape of the
equation of state.


title: A computationally tractable version of the collective model

abstract:
  A computationally tractable version of the Bohr-Mottelson collective model is
presented which makes it possible to diagonalize realistic collective models
and obtain convergent results in relatively small appropriately chosen
subspaces of the collective model Hilbert space. Special features of the
proposed model is that it makes use of the beta wave functions given
analytically by the softened-beta version of the Wilets-Jean model, proposed by
Elliott et al., and a simple algorithm for computing SO(5) > SO(3) spherical
harmonics. The latter has much in common with the methods of Chacon, Moshinsky,
and Sharp but is conceptually and computationally simpler. Results are
presented for collective models ranging from the sherical vibrator to the
Wilets-Jean and axially symmetric rotor-vibrator models.


title: Proton-tetraneutron elastic scattering

abstract:
  We analyze the elastic scattering of protons on a 4n system. This was used as
part of the detection technique of a recent experiment [1] to search for the 4n
(tetraneutron) as a bound particle. We show that it is unlikely that this
process alone could yield the events reported in ref. [1], unless the 4n has an
anomalously large backward elastic scattering amplitude.


title: Spectra of anti-nucleons in the vacuum of finite nuclei

abstract:
  The quantum vacuum in a many-body system of finite nuclei has been
investigated within the relativistic Hartree approach which describes the bound
states of nucleons and anti-nucleons consistently. The contributions of the
Dirac sea to the source terms of the meson-field equations are taken into
account up to the one-nucleon loop and one-meson loop. The tensor couplings for
the $\omega$- and $\rho$-meson are included in the model. After adjusting the
parameters of the model to the properties of spherical nuclei, a large
effective nucleon mass $m^{*}/M_{N} \approx 0.78$ is obtained. The overall
nucleon spectra of shell-model states are in agreement with the data. The
computed anti-nucleon spectra in the vacuum differ about 20 -- 30 MeV with and
without the tensor-coupling effects.


title: Stellar matter in the Quark-Meson-Coupling Model with neutrino trapping

abstract:
  The properties of hybrid stars formed by hadronic and quark matter in
$\beta$-equilibrium are described by appropriate equations of state (EoS) in
the framework of the quark meson coupling (QMC) model. In the present work we
include the possibility of trapped neutrinos in the equation of state and
obtain the properties of the related hybrid stars. We use the quark meson
coupling model for the hadron matter and two possibilities for the quark matter
phase, namely, the unpaired quark phase and the color-flavor locked phase. The
differences are discussed and a comparison with other relativistic EoS is done.


title:
Clustering in stable and unstable nuclei in $p$-shell and $sd$-shell
  regions

abstract:
  According to microscopic calculations with antisymmetrized molecular
dynamics, we studied cluster features in stable and unstable nuclei. A variety
of structure was found in stable and unstable nuclei in the $p$-shell and
$sd$-shell regions. The structure of excited states of $^{12}$Be was
investigated, while in $sd$-shell nuclei we focused on molecular states and
deformed states. The deformed states in $^{28}$Si and $^{40}$Ca were discussed
in connection with the high-lying molecular states. Appealing molecular states
in $^{36}$Ar and $^{24}$Mg were suggested. The results signified that both
clustering of nucleons and mean-field formation are essential features in
$sd$-shell nuclei as well as $p$-shell nuclei.


title: Screening Effect in Quark-Hadron Mixed Phase

abstract:
  Possibility of the structured mixed phases at first order phase transitions
in neutron stars is reexamined by taking into account the charge screening
effect. The Maxwell construction is shown to be not conflicted with the Gibbs
conditions once the Coulomb potential is properly taken into account. Taking
the hadron-quark deconfinement transition as an example, we explicitly
demonstrate a mechanical instability of the geometrical structure of the
structured mixed phase by the charge screening effect. In this case we have
effectively the picture given by the Maxwell construction.


title: Meson Condensations in High-Density Matter

abstract:
  Recent studies on meson condensations (pions and kaons) in high-density
hadronic matter are reviewed. After summarizing onset mechanisms of pion and
kaon condensations, we discuss implications for neutron star phenomena such as
rapid cooling through neutrino emission, static and dynamic properties of
neutron stars. Recent studies on coexistence problem of pion and kaon
condensations are briefly introduced. Finally, relevance of meson condensations
in hadronic matter to those in color superconductivity are briefly mentioned.


title: Formation of hot heavy nuclei in supernova explosions

abstract:
  We point out that during the supernova II type explosion the thermodynamical
condition of stellar matter between the protoneutron star and the shock front
corresponds to the nuclear liquid-gas phase coexistence region, which can be
investigated in nuclear multifragmentation reactions. We have demonstrated,
that neutron-rich hot heavy nuclei can be produced in this region. The
production of these nuclei may influence dynamics of the explosion and
contribute to the synthesis of heavy elements.


title: Threshold pi^0 photo- and electro-production in a meson-exchange model

abstract:
  We show that, within a meson-exchange dynamical model describing well most of
the existing pion electromagnetic production data up to the second resonance
region, one is also able to obtain a good agreement with the pi^0 photo- and
electroproduction data near threshold. In the case of pi^0 production, the
effects of final state interaction in the threshold region are nearly saturated
by single charge exchange rescattering. This indicates that in ChPT, it might
be sufficient to carry out the calculation just up to one-loop diagrams for
threshold neutral pion production.


title:
J/psi production in a gluon plasma produced in Au-Au collisions at the
  Relativistic Heavy Ion Collider

abstract:
  Centrality dependence of J/psi production in Au-Au collisions at 200 GeV
nucleon-nucleon center of mass energy is studied using the Glauber model plus
the kinetic formation model. Initial J/psi production and destruction by
incoming nucleons are described by the Glauber model. J/psi-charm equilibration
in the gluon plasma is described by the kinetic formation model. We explore the
possibility of J/psi suppression suggested by the recent PHENIX data. We show
that the J/psi yield monotonically decreases with increasing centrality in the
kinetic formation model when the charm mass is smaller than a critical mass.
The final J/psi yield is between the value after the Glauber suppression and
the dynamical equilibrium value. This underscores the importance of both J/psi
production from d-Au collisions, which is essential in determining the Glauber
suppression, and high statistics Au-Au data, which can further constrain final
state J/psi-charm equilibration.


title: Photoproduction of pentaquark cascades from nucleons

abstract:
  The cross sections for production of pentaquark $\Xi^+_5$ from the reaction
$\gamma p\to K^0K^0\Xi^+_5$ and $\Xi^{--}_5$ from the reaction $\gamma n\to
K^+K^+\Xi^{--}_5$ are evaluated in a hadronic model that includes their
couplings to both $\Sigma\bar K$ and $\Sigma\bar K^*$. With these coupling
constants determined from the empirical $\pi NN(1710)$ and $\rho NN(1710)$
coupling constants by assuming that $\Xi^+_5$, $\Xi^{--}_5$, and N(1710) belong
to the same antidecuplet of spin 1/2 and positive parity, and using form
factors at strong interaction vertices similar to those for pentaquark
$\Theta^+$ production in photonucleon reactions, we obtain a cross section of
about 0.03-0.6 nb for the reaction $\gamma p\to K^0K^0\Xi^+_5$ and about
0.1-0.6 nb for the reaction $\gamma n\to K^+K^+\Xi^{--}_5$ at photon energy
$E_\gamma=4.5$ GeV, depending on the value of the coupling constant
$g_{K^*\Sigma\Xi_5}$.


title:
Sequence of Potentials Interpolating between the U(5) and E(5)
  Symmetries

abstract:
  It is proved that the potentials of the form $\beta^{2n}$ (with $n$ being
integer) provide a ``bridge'' between the U(5) symmetry of the Bohr Hamiltonian
with a harmonic oscillator potential (occuring for $n=1$) and the E(5) model of
Iachello (Bohr Hamiltonian with an infinite well potential, materialized for
infinite $n$). Parameter-free (up to overall scale factors) predictions for
spectra and B(E2) transition rates are given for the potentials $\beta^4$,
$\beta^6$, $\beta^8$, corresponding to $R_4=E(4)/E(2)$ ratios of 2.093, 2.135,
2.157 respectively, compared to the $R_4$ ratios 2.000 of U(5) and 2.199 of
E(5). Hints about nuclei showing this behaviour, as well as about potentials
``bridging'' the E(5) symmetry with O(6) are briefly discussed. A note about
the appearance of Bessel functions in the framework of E(n) symmetries is given
as a by-product.


title:
Ground State Bands of the E(5) and X(5) Critical Symmetries Obtained
  from Davidson Potentials through a Variational Procedure

abstract:
  Davidson potentials of the form $\beta^2 +\beta_0^4/\beta^2$, when used in
the original Bohr Hamiltonian for $\gamma$-independent potentials bridge the
U(5) and O(6) symmetries. Using a variational procedure, we determine for each
value of angular momentum $L$ the value of $\beta_0$ at which the derivative of
the energy ratio $R_L=E(L)/E(2)$ with respect to $\beta_0$ has a sharp maximum,
the collection of $R_L$ values at these points forming a band which practically
coincides with the ground state band of the E(5) model, corresponding to the
critical point in the shape phase transition from U(5) to O(6). The same
potentials, when used in the Bohr Hamiltonian after separating variables as in
the X(5) model, bridge the U(5) and SU(3) symmetries, the same variational
procedure leading to a band which practically coincides with the ground state
band of the X(5) model, corresponding to the critical point of the U(5) to
SU(3) shape phase transition. A new derivation of the Holmberg-Lipas formula
for nuclear energy spectra is obtained as a by-product.


title:
Analysis of kaon spectra at SIS energies - what remains from the KN
  potential

abstract:
  We study the reaction Au+Au at 1.48 AGeV and analyze the influence of the KN
optical potential on cm spectra and azimuthal distributions at mid-rapidity. We
find a significant change of the yields but only slight changes in the shapes
of the distributions when turning off the optical potential. However, the
spectra show contributions from different reaction times, where early kaons
contribute stronger to higher momenta and late kaons to lower momenta.
Azimuthal distributions of the kaons at mid-rapidity show a strong centrality
dependence. Their shape is influenced by the KN optical potential as well as by
re-scattering.


title:
Realistic Calculations of One- and Two-Hadron Emission Processes off
  Few- and Many-Body Nuclei

abstract:
  The exclusive electro-disintegration processes 2H(e,e'p)n, 3He(e,e'p)2H,
3He(e,e'p)pn, 3He(e,e'pp)n and 4He(e,e'p)3H have been calculated using
realistic few-body wave functions and treating final state interaction (FSI)
effects within a generalized eikonal approach. The semi-inclusive scattering
A(e,e'p)X off complex nuclei has been analyzed using many-body wave functions
for 16O and 40Ca, obtained within the framework of a linked cluster expansion
and taking FSI into account by a Glauber-type approach. The effect of color
transparency has also been included by considering the Finite Formation Time
(FFT) that the hit hadron needs to reach its asymptotic physical state.


title:
Partonic effects on higher-order anisotropic flows in relativistic
  heavy-ion collisions

abstract:
  Higher-order anisotropic flows $v_{4}$ and $v_{6}$ in heavy ion collisions at
the Relativistic Heavy Ion Collider are studied in a multiphase transport model
that has previously been used successfully for describing the elliptic flow
$v_2$ in these collisions. We find that the same parton scattering cross
section of about 10 \textrm{mb} used in explaining the measured $v_2$ can also
reproduce the recent data on $v_{4}$ and $v_{6}$ from Au + Au collisions at
$\sqrt{s}=200$ \textrm{AGeV}. It is further found that the $% v_{4}$ is a more
sensitive probe of the initial partonic dynamics in these collisions than
$v_{2}$. Moreover, higher-order parton anisotropic flows are nonnegligible and
satisfy the scaling relation $v_{n,q}(p_{T})\sim v_{2,q}^{n/2}(p_{T})$, which
leads naturally to the observed similar scaling relation among hadron
anisotropic flows when the coalescence model is used to describe hadron
production from the partonic matter.


title:
Mean Field Calculation of Thermal Properties of Simple Nucleon Matter on
  a Lattice

abstract:
  Thermal properties of single species nucleon matter are investigated assuming
a simple form of the nucleon-nucleon interaction. The nucleons are placed on a
cubic lattice, hopping from site to site and interacting through a
spin-dependent force, as in the extended, attractive Hubbard model. A mean
field calculation in the Hartree-Fock Bogoliubov approximation suggests that
the superfluid ground state generated by strong nucleon pairing undergoes a
second-order phase transition to a normal state as the temperature increases.
The calculation is shown to lead to a promising description of the thermal
properties of low-density neutron matter. A possibility of a density wave phase
is also examined.


title: Nonstrange and other unitarity partners of the exotic Theta+ baryon

abstract:
  Given presently known empirical information about the exotic Theta+ baryon,
we analyze possible properties of its SU(3)F partners, paying special attention
to the nonstrange member of the antidecuplet N*. The modified PWA analysis
presents two candidate masses, 1680 MeV and 1730 MeV. In both cases the N*
should be highly inelastic. The theoretical analysis, based on the soliton
picture and assumption of Gamma(Theta+) < 5 MeV, shows that most probably
Gamma(N*) < 30 MeV. Similar analysis for Xi3/2 predicts its width to be not
more than about 10 MeV. Our results suggest several directions for experimental
studies that may clarify properties of the antidecuplet baryons, and structure
of their mixing with other baryons.


title:
Three-body model for the complete fusion of a two-cluster composite
  projectile with a heavy target

abstract:
  The purpose of this work is to show that within a three-body description, the
complete fusion process and the target excitation by the projectile can be
taken into account by introducing a three-body optical potential in the
formalism. We give a schematic description of such a potential and points to
ways of testing the validity of the CDCC.


title: Hot Nuclear Matter in Asymmetry Chiral Sigma Model

abstract:
  In the frame work of SU(2) chiral sigma model, the nuclear matter properties
at zero and finite temperature have been investigated. We have analyzed the
nuclear matter equation of state by varying different parameters, which agrees
well with the one derived from the heavy-ion collision experiment at extreme
densities and reliable realistic(DBHF) model at low density region. We have
then calculated the temperature dependent asymmetric nuclear matter, also
investigated the critical temperature of liquid gas phase transition and
compared with the experimental data. We found that the critical temperature in
our model is in the range of 14-20 MeV.


title:
Energy averages over regular and chaotic states in the decay out of
  superdeformed bands

abstract:
  We describe the decay out of a superdeformed band using the methods of
reaction theory. Assuming that decay-out occurs due to equal coupling (on
average) to a sea of equivalent chaotic normally deformed (ND) states, we
calculate the average intraband decay intensity and show that it can be written
as an ``optical'' background term plus a fluctuation term, in total analogy
with average nuclear cross sections. We also calculate the variance in closed
form. We investigate how these objects are modified when the decay to the ND
states occurs via an ND doorway and the ND states' statistical properties are
changed from chaotic to regular. We show that the average decay intensity
depends on two dimensionless variables in the first case while in the second
case, four variables enter the picture.