title:
On the D-wave state component of the deuteron in the Nambu-Jona-Lasinio
  model of light nuclei

abstract:
  The D-wave state component of the neutron-proton bound state in the deuteron
is calculated in the Nambu-Jona-Lasinio model of light nuclei - the
relativistically covariant quantum field theoretic approach to the description
of low-energy nuclear forces. The theoretical value of the fraction of the
D-wave state relative to the S-wave state is equal to eta_d = 0.0238. This
agrees well with the phenomenological value eta_d = 0.0256(4) quoted by
Kamionkowski and Bahcall (ApJ. 420, 884 (1994)).


title: Resonant mesomolecule formation

abstract:
  The dtm and ddm resonant fusion rates are calculated taking into account
finite resonance width and subthreshold resonances. Calculations do not use
multipole expansion of the potential. The obtained ddm resonant fusion rates
are compared with recent data at 30-360 K.


title: Are Occupation Numbers Observable?

abstract:
  The question of whether occupation numbers and momentum distributions of
nucleons in nuclei are observables is considered from an effective field theory
perspective. Field redefinitions lead to variations that imply the answer is
negative, as illustrated in the interacting Fermi gas at low density.
Implications for the interpretation of (e,e'p) experiments with nuclei are
discussed.


title:
Probing the effectiveness: chiral perturbation theory calculations of
  low-energy electromagnetic reactions on deuterium

abstract:
  I summarize three recent calculations of electromagnetic reactions on
deuterium in chiral perturbation theory. All of these calculations were carried
out to O(Q^4), i.e. next-to-next-to-leading order. The reactions discussed here
are: elastic electron-deuteron scattering, Compton scattering on deuterium, and
the photoproduction of neutral pions from deuterium at threshold.


title: Nuclei beyond the drip line

abstract:
  In a Thomas-Fermi model, calculations are presented for nuclei beyond the
nuclear drip line at zero temperature. These nuclei are in equilibrium by the
presence of an external gas, as may be envisaged in the astrophysical scenario.
We find that there is a limiting asymmetry beyond which these nuclei can no
longer be made stable.


title:
A Quasi-Classical Model of Intermediate Velocity Particle Production in
  Asymmetric Heavy Ion Reactions

abstract:
  The particle emission at intermediate velocities in mass asymmetric reactions
is studied within the framework of classical molecular dynamics. Two reactions
in the Fermi energy domain were modelized, $^{58}$Ni+C and $^{58}$Ni+Au at 34.5
MeV/nucleon. The availability of microscopic correlations at all times allowed
a detailed study of the fragment formation process. Special attention was paid
to the physical origin of fragments and emission timescales, which allowed us
to disentangle the different processes involved in the mid-rapidity particle
production. Consequently, a clear distinction between a prompt pre- equilibrium
emission and a delayed aligned asymmetric breakup of the heavier partner of the
reaction was achieved.


title: Generalized Ladder Operators for Shape-invariant Potentials

abstract:
  A general form for ladder operators is used to construct a method to solve
bound-state Schr\"odinger equations. The characteristics of supersymmetry and
shape invariance of the system are the start point of the approach. To show the
elegance and the utility of the method we use it to obtain energy spectra and
eigenfunctions for the one-dimensional harmonic oscillator and Morse potentials
and for the radial harmonic oscillator and Coulomb potentials.


title: Analytical solution of the dynamical spherical MIT bag

abstract:
  We prove that when the bag surface is allowed to move radially, the equations
of motion derived from the MIT bag Lagrangian with massless quarks and a
spherical boundary admit only one solution, which corresponds to a bag
expanding at the speed of light. This result implies that some new physics
ingredients, such as coupling to meson fields, are needed to make the dynamical
bag a consistent model of hadrons.


title: A dynamical chiral bag model

abstract:
  We study a dynamical chiral bag model, in which massless fermions are
confined within an impenetrable but movable bag coupled to meson fields. The
self-consistent motion of the bag is obtained by solving the equations of
motion exactly assuming spherical symmetry. When the bag interacts with an
external meson wave we find three different kinds of resonances: {\it
fermionic}, {\it geometric}, and $\sigma$-resonances. We discuss the
phenomenological implications of our results.


title:
The two-nucleon system in the $\Delta$ region including full meson
  retardation

abstract:
  A model is developed for the hadronic and electromagnetic interaction in the
two-nucleon system above pion threshold in the framework of meson, nucleon and
$\Delta$ degrees of freedom. It is based on time-ordered perturbation theory
and includes full meson retardation in potentials and exchange currents as well
as loop contributions to the nucleonic one-body current. Results for $NN$
scattering and deuteron photodisintegration are presented.


title: Effect of higher orbital angular momenta in the baryon spectrum

abstract:
  We have performed a Faddeev calculation of the baryon spectrum for the chiral
constituent quark model including higher orbital angular momentum states. We
have found that the effect of these states is important, although a description
of the baryon spectrum of the same quality as the one given by including only
the lowest-order configurations can be obtained. We have studied the effect of
the pseudoscalar quark-quark interaction on the relative position of the
positive- and negative-parity excitations of the nucleon as well as the effect
of varying the strength of the color-magnetic interaction.


title:
Neutron structure function $F_2^n(x)$ from deep inelastic electron
  scattering off few-nucleon systems

abstract:
  The possibility of a reliable extraction of the neutron deep inelastic
structure function, $F_2^n(x)$, for $ x < 0.85$ from joint measurements of deep
inelastic structure functions of deuteron, $^{3}He$ and $^{3}H$ is
investigated. The model dependence in this extraction, linked to the possible
different interactions between nucleons in nuclei, is shown to be weak, if the
nuclear structure effects are properly taken into account. A combined analysis
of the deep inelastic structure functions of these nuclei is proposed to study
effects beyond the impulse approximation.


title: Low lying S=-1 excited baryons and chiral symmetry

abstract:
  The s-wave meson-baryon interaction in the $S = -1$ sector is studied by
means of coupled-channels, using the lowest-order chiral Lagrangian and the N/D
method to implement unitarity. The loops are regularized using dimensional
renormalization. In addition to the previously studied $\Lambda (1405)$,
employing this chiral approach leads to the dynamical generation of two more
s-wave hyperon resonances, the $\Lambda(1670)$ and $\Sigma(1620)$ states. We
make comparisons with experimental data and look for poles in the complex plane
obtaining the couplings of the resonances to the different final states. This
allows us to identify the $\Lambda (1405)$ and the $\Lambda(1670)$ resonances
with $\bar{K}N$ and $K\Xi$ quasibound states, respectively.


title: Recent Developments in the Nuclear Many-Body Problem

abstract:
  The study of quantum chromodynamics (QCD) over the past quarter century has
had relatively little impact on the traditional approach to the low-energy
nuclear many-body problem. Recent developments are changing this situation. New
experimental capabilities and theoretical approaches are opening windows into
the richness of many-body phenomena in QCD. A common theme is the use of
effective field theory (EFT) methods, which exploit the separation of scales in
physical systems. At low energies, effective field theory can explain how
existing phenomenology emerges from QCD and how to refine it systematically.
More generally, the application of EFT methods to many-body problems promises
insight into the analytic structure of observables, the identification of new
expansion parameters, and a consistent organization of many-body corrections,
with reliable error estimates.


title: Nucleon deformation in finite nuclei

abstract:
  The deformation of a nucleon embedded in various finite nuclei is considered
by taking into account the distortion of the chiral profile functions under the
action of an external field representing the nuclear density. The baryon charge
distribution of the nucleon inside light, medium-heavy and heavy nuclei is
discussed. The mass of the nucleon decreases as it is placed deeper inside the
nucleus and reaches its minimum at the center of the nucleus. We discuss the
quantization of non-spherical solitons and its consequences for the mass
splitting of the delta states. We show that bound nucleons acquire an intrinsic
quadrupole moment due to the deformation effects. These effects are maximal for
densities of nuclei about \rho(R)\sim 0.3...0.35 \rho(0). We also point out
that scale changes of the electromagnetic radii can not simply be described by
an overall swelling factor.


title: Charge Screening at First Order Phase Transitions

abstract:
  Possibility of structured mixed phases at first order phase transitions is
examined with taking into account of charge screening and surface effects.
Hadron-quark phase transition in dense neutron star interior is considered, as
concrete example.


title:
Beyond the relativistic Hartree mean-field approximation: energy
  dependent effective mass

abstract:
  The standard relativistic mean-field model is extended by including dynamical
effects that arise in the coupling of single-nucleon motion to collective
surface vibrations. A phenomenological scheme, based on a linear ansatz for the
energy dependence of the scalar and vector components of the nucleon
self-energy for states close to the Fermi surface, allows a simultaneous
description of binding energies, radii, deformations and single-nucleon spectra
in a self-consistent relativistic framework. The model is applied to the
spherical, doubly closed-shell nuclei 132Sn and 208Pb.


title: Finite temperature effects on the antikaon optical potential

abstract:
  By solving the Bethe-Goldstone equation, we have obtained the $\bar{K}$
optical potential from the $\bar{K}N$ effective interaction in nuclear matter
at T=0. We have extended the model by incorporating finite temperature effects
in order to adapt our calculations to the experimental conditions in heavy-ion
collisions. In the rank of densities ($0-2\rho_0$), the finite temperature
$\bar{K}$ optical potential shows a smooth behaviour if we compare it to the
T=0 outcome. Our model has also been applied to the study of the ratio between
$K^+$ and $K^-$ produced at GSI with $T$ around 70 MeV. Our results point at
the necessity of introducing an attractive $\bar{K}$ optical potential.


title:
Meson Dynamics and the resulting "3-Nucleon-Force" diagrams: Results
  from a simplified test case

abstract:
  A simplified 1D (one-dimensional) model for a generalized 3N system is
considered, as a testing ground for the explicit treatment of the meson
dynamics in this system. We focus attention on the irreducible diagrams
generated by the pion dynamics in the 3N system, and in particular to a new
type of three-nucleon force discussed recently in the literature, and generated
by the one-pion-exchange mechanism in presence of a nucleon-nucleon
correlation. It is found that these new terms in the simplified model have an
approximately 30% effect compared to the standard three-nucleon force terms in
a `Triton' binding energy calculation. It is suggested that this effect should
also not be ignored in realistic calculations.


title: Deeply bound pionic atoms from the $(\gamma,p)$ reaction in nuclei

abstract:
  We study the $(\gamma,p)$ reaction on $^{208}Pb$ leading to $^{207}Pb$ with a
bound pion attached to it in the lowest 1s or 2p pionic levels. The reaction
can be made recoilless to optimize the production cross section but we must
choose a bit higher photon energy to overcome the Coulomb barrier in the proton
emission. The cross sections obtained are easily measurable and can be larger
than 50 per cent of the background from inclusive ($\gamma$,p). This makes it a
clear case for the detection of the pionic atom signals, converting this
reaction into a practical tool to produce deeply bound pionic atoms.


title: Nuclear Anapole Moments

abstract:
  Nuclear anapole moments are parity-odd, time-reversal-even E1 moments of the
electromagnetic current operator. Although the existence of this moment was
recognized theoretically soon after the discovery of parity nonconservation
(PNC), its experimental isolation was achieved only recently, when a new level
of precision was reached in a measurement of the hyperfine dependence of atomic
PNC in 133Cs. An important anapole moment bound in 205Tl also exists. In this
paper, we present the details of the first calculation of these anapole moments
in the framework commonly used in other studies of hadronic PNC, a meson
exchange potential that includes long-range pion exchange and enough degrees of
freedom to describe the five independent $S-P$ amplitudes induced by
short-range interactions. The resulting contributions of pi-, rho-, and
omega-exchange to the single-nucleon anapole moment, to parity admixtures in
the nuclear ground state, and to PNC exchange currents are evaluated, using
configuration-mixed shell-model wave functions. The experimental anapole moment
constraints on the PNC meson-nucleon coupling constants are derived and
compared with those from other tests of the hadronic weak interaction. While
the bounds obtained from the anapole moment results are consistent with the
broad ``reasonable ranges'' defined by theory, they are not in good agreement
with the constraints from the other experiments. We explore possible
explanations for the discrepancy and comment on the potential importance of new
experiments.


title:
Recent results on the nonmesonic weak decay of hypernuclei within a
  one-meson-exchange model

abstract:
  We update our previous results for the nonmesonic decay of $^{12}_\Lambda$C
and $^5_\Lambda$He. We pay special attention to the role played by Final State
Intreractions on the decay observables. We follow a One-Meson-Exchange model
which includes the exchange of the $\pi, \rho, K, K^*, \eta$ and $\omega$
mesons. We also present recent predictions for different observables concerning
the decay of the doubly strange $^6_{\Lambda \Lambda}$He hypernucleus.


title: What determines the $K^-$ multiplicity at energies around 1-2 AGeV?

abstract:
  In heavy ion reactions at energies around 1-2 AGeV the measured $K^-$ yields
appear rather high as compared to pp collisions as shown by the KaoS
collaboration. Employing IQMD simulations, we show that this is caused by the
fact that the dominant production channel is not $BB\to BBK^+K^-$ but the
mesonic $\Lambda(\Sigma) \pi \to K^-B$ reaction. Because the $\Lambda $
($\Sigma$) stem from the reaction $BB \to \Lambda(\Sigma) K^+ B$, the $K^+$ and
the $K^-$ yield are strongly correlated, i.e. the $K^-/K^+$ ratio occurs to be
nearly independent of the impact parameter as found experimentally. $K^-$ are
continuously produced but also very quickly reabsorbed leading to an almost
identical rate for production and reabsorption. The final $K^-$ yield is
strongly influenced by the $K^+N$ (due to their production via the
$\Lambda(\Sigma)$) but very little by the $K^-$N potential.


title: Modeling the strangeness content of hadronic matter

abstract:
  The strangeness content of hadronic matter is studied in a string-flip model
that reproduces various aspects of the QCD-inspired phenomenology, such as
quark clustering at low density and color deconfinement at high density, while
avoiding long range van der Waals forces. Hadronic matter is modeled in terms
of its quark constituents by taking into account its internal flavor (u,d,s)
and color (red, blue, green) degrees of freedom. Variational Monte-Carlo
simulations in three spatial dimensions are performed for the ground-state
energy of the system. The onset of the transition to strange matter is found to
be influenced by weak, yet not negligible, clustering correlations. The phase
diagram of the system displays an interesting structure containing both
continuous and discontinuous phase transitions. Strange matter is found to be
absolutely stable in the model.


title:
A Study of Parton Energy Loss in Au+Au Collisions at RHIC using
  Transport Theory

abstract:
  Parton energy loss in Au+Au collisions at RHIC energies is studied by
numerically solving the relativistic Boltzmann equation for the partons
including $2 \leftrightarrow 2$ and $2 \to 2 + final state radiation$ collision
processes. Final particle spectra are obtained using two hadronization models;
the Lund string fragmentation and independent fragmentation models. Recent,
preliminary $\pi^0$ transverse momentum distributions from central Au+Au
collisions at RHIC are reproduced using gluon-gluon scattering cross sections
of 5-12 mb, depending upon the hadronization model. Comparisons with the HIJING
jet quenching algorithm are made.


title: Light Front Nuclear Theory

abstract:
  High energy scattering experiments involving nuclei are typically analyzed in
terms of light front variables. The desire to provide realistic,relativistic
wave functions expressed in terms of these variables led me to try to use light
front dynamics to compute nuclear wave functions. Here calculations of infinite
nuclear matter in the mean field approximation and also in a light front
version of Bruckner theory which includes NN correlations are reviewed.
Applications of these wave functions to nuclear deep inelastic scattering and
Drell-Yan processes are discussed. We find that relativistic mean field theory
produces no EMC binding effect.


title: Numerical study of the density of states for the bag model

abstract:
  The density of states for an extended MIT bag model is studied numerically by
using a parameterized smooth representation which provides the best fit to the
numerical data. It is found that the mass dependence of the surface term in the
density of states agrees with that derived from multi-reflection theory
calculation. The mass dependence of the curvature term in the density of states
is extracted for finite values of the quark mass. The scaling properties of the
data, assumed in the parameterization, are studied. The difference between the
parameterized smooth representation determined by a best fit and the results
derived from direct smoothing of the numerical data are discussed. The
fluctuations in the density of states are also discussed. We provide a smooth
representation of the density of states of a spherical cavity for
non-relativistic particles.


title: Nucleons and Isobars at finite density ($\rho$) and temperature (T)

abstract:
  The importance of studying matter at high $\rho$ increases as more
astrophysical data becomes available from recently launched spacecrafts. The
importance of high T studies derives from heavy ion data. In this paper we set
up a formalism to study the nucleons and isobars with long and short range
potentials non-pertubatively, bosonizing and expanding semi-classically the
Feyman integrals up to one loop. We address the low density, finite T
problem=A0 first, the case relevant to heavy ion collisions, hoping to adresss
the high density case later. Interactions change the nucleon and isobar numbers
at different $\rho$ and T non-trivially.


title: Coherent and chaotic properties of nuclear pairing

abstract:
  The properties of the pairing interaction in the shell model framework are
considered with the aid of the exact numerical solution utilizing the quasispin
symmetry. We emphasize the features which are out of reach for the usual
approximate techniques based on the BCS approach supplemented by the random
phase approximation treatment of pair vibrations, especially in the region of
weak pairing where the BCS+RPA theory fails. For the first time chaotic aspects
of the mixing generated by the pairing interaction are studied. The level
repulsion and large information entropy of the eigenstates coexist with the
absence of thermalization of single-particle motion. The full spectrum of pair
vibration in average displays the spin dependence similar to that for a rigid
rotor.


title:
Comparison between chiral and meson-theoretic nucleon-nucleon potentials
  through (p,p') reactions

abstract:
  We use proton-nucleus reaction data at intermediate energies to test the
emerging new generation of chiral nucleon-nucleon (NN) potentials. Predictions
from a high quality one-boson-exchange (OBE) force are used for comparison and
evaluation. Both the chiral and OBE models fit NN phase shifts accurately, and
the differences between the two forces for proton-induced reactions are small.
A comparison to a chiral model with a less accurate NN description sets the
scale for the ability of such models to work for nuclear reactions.


title:
Transition from BCS pairing to Bose-Einstein condensation in low-density
  asymmetric nuclear matter

abstract:
  We study the isospin-singlet neutron-proton pairing in bulk nuclear matter as
a function of density and isospin asymmetry within the BCS formalism. In the
high-density, weak-coupling regime the neutron-proton paired state is strongly
suppressed by a minor neutron excess. As the system is diluted, the BCS state
with large, overlapping Cooper pairs evolves smoothly into a Bose-Einstein
condensate of tightly bound neutron-proton pairs (deuterons). In the resulting
low-density system a neutron excess is ineffective in quenching the pair
correlations because of the large spatial separation of the deuterons and
neutrons. As a result, the Bose-Einstein condensation of deuterons is weakly
affected by an additional gas of free neutrons even at very large asymmetries.


title: Shell-Model Calculations with Realistic Effective Interactions

abstract:
  In this paper, we present some results of shell-model calculations employing
effective interactions derived from the CD-Bonn free nucleon-nucleon potential.
These concern 18O, 134Te, and 210Po, and are part of a comprehensive study of
nuclei around doubly closed shells. Comparison of the calculated results with
experimental data illustrates the degree of accuracy of modern realistic
shell-model calculations.


title: In-medium chiral perturbation theory beyond the mean-field approximation

abstract:
  An explicit expression of the generating functional of two-flavor low-energy
QCD with external sources in the presence of non-vanishing nucleon densities
has been derived recently [1]. Within this approach we derive power counting
rules for the calculation of in-medium pion properties. We develop the
so-called standard rules for residual nucleon energies of the order of the pion
mass and a modified scheme (non-standard counting) for vanishing residual
nucleon energies. We also establish the different scales for the range of
applicability of this perturbative expansion, which are \sqrt{6}\pi f_\pi\simeq
0.7 GeV for the standard and 6\pi^2 f_\pi^2/2m_N\simeq 0.27 GeV for
non-standard counting, respectively. We have performed a systematic analysis of
n-point in-medium Green functions up to and including next-to-leading order
when the standard rules apply. These include the in-medium contributions to
quark condensates, pion propagators, pion masses and couplings of the
axial-vector, vector and pseudoscalar currents to pions. In particular, we find
a mass shift for negatively charged pions in heavy nuclei that agrees with
recent determinations from deeply bound pionic Pb-207. We have also established
the absence of in-medium renormalization in the \pi^0 \to \gamma\gamma decay
amplitude up to the same order. The study of \pi\pi scattering requires the use
of the non-standard counting and the calculation is done at leading order. Even
at that order we establish new contributions not considered so far. We also
point towards further possible improvements of this scheme and touch upon its
relation to more conventional many-body approaches.


title: Relativistic Hartree-Bogoliubov description of deformed light nuclei

abstract:
  The Relativistic Hartree-Bogoliubov model is applied in the analysis of
ground-state properties of Be, B, C, N, F, Ne and Na isotopes. The model uses
the NL3 effective interaction in the mean-field Lagrangian, and describes
pairing correlations by the pairing part of the finite range Gogny interaction
D1S. Neutron separation energies, quadrupole deformations, nuclear matter
radii, and differences in radii of proton and neutron distributions are
compared with recent experimental data.


title:
Spin-isospin excitations and beta+/EC half-lives of medium-mass deformed
  nuclei

abstract:
  A selfconsistent approach based on a deformed HF+BCS+QRPA method with
density-dependent Skyrme forces is used to describe beta+ decay properties in
even-even deformed proton rich nuclei. Residual spin-isospin forces are
included in the particle-hole and particle-particle channels. The quasiparticle
basis contains neutron-neutron and proton-proton pairing correlations in the
BCS approach, while neutron-proton pairing interaction is treated as a residual
force in QRPA. We discuss the sensitivity of Gamow-Teller strength
distributions and beta+/EC half-lives to deformation, pairing and the strength
of the particle-particle interaction. The dependence on deformation is also
compared to that of spin M1 strength distributions.


title: Strange Goings on in Quark Matter

abstract:
  We review recent work on how the superfluid state of three flavor quark
matter is affected by non-zero quark masses and chemical potentials.


title: Relativistic Pseudospin Symmetry and the Structure of Nuclear States

abstract:
  We show that a natural explanation for characteristic features (angular
momentum and radial quantum numbers) of pseudospin doublets and intruder levels
in nuclei can be obtained by combining the relativistic attributes of
pseudospin symmetry with known properties of Dirac bound states.


title: Relativistic Pseudospin Symmetry in Nuclei

abstract:
  We review recent developments that show that pseudospin symmetry is an
approximate relativistic symmetry of the Dirac Hamiltonian with realistic
nuclear mean field potentials.


title: Extended Superscaling of Electron Scattering from Nuclei

abstract:
  An extended study of scaling of the first and second kinds for inclusive
electron scattering from nuclei is presented. Emphasis is placed on the
transverse response in the kinematic region lying above the quasielastic peak.
In particular, for the region in which electroproduction of resonances is
expected to be important, approximate scaling of the second kind is observed
and the modest breaking of it is shown probably to be due to the role played by
an inelastic version of the usual scaling variable.


title:
Quadrupole Oscillations as Paradigm of the Chaotic Motion in Nuclei.
  Part 1

abstract:
  We have presented a complete description of classical dynamics generated by
the Hamiltonian of quadrupole nuclear oscillations and identified those
peculiarities of quantum dynamics that can be interpreted as quantum
manifestations of classical stochasticity. Particular attention has been given
to investigation of classical dynamics in the potential energy surface with a
few local minima. A new technique is suggested for determination of the
critical energy of the transition to chaos. It is simpler than criteria of
transition to chaos connected with one or another version of overlap resonances
criterion. We have numerically demonstrated that for potential with a localized
unstable region motion becomes regular at the high energy again, i.e.
transition regularity-chaos-regularity {R - C - R} takes place for these
potentials. The variations of statistical properties of energy spectrum in the
process of {R - C - R) transition have been studied in detail. We proved that
the type of the classical motion is correlated with the structure of the
eigenfunctions of highly excited states in the (R - C - R) transition. Shell
structure destruction induced by the increase of nonintegrable perturbation was
analyzed.


title:
The damping width of giant dipole resonances of cold and hot nuclei: a
  macroscopic model

abstract:
  A phenomenological macroscopic model of the Giant Dipole Resonance (GDR)
damping width of cold- and hot-nuclei with ground-state spherical and
near-spherical shapes is developed. The model is based on a generalized Fermi
Liquid model which takes into account the nuclear surface dynamics. The
temperature dependence of the GDR damping width is accounted for in terms of
surface- and volume-components. Parameter-free expressions for the damping
width and the effective deformation are obtained. The model is validated with
GDR measurements of the following nuclides, $^{39,40}$K, $^{42}$Ca, $^{45}$Sc,
$^{59,63}$Cu, $^{109-120}$Sn,$^{147}$Eu, $^{194}$Hg, and $^{208}$Pb, and is
compared with the predictions of other models.


title: Mesons as Bound States of Confined Quarks: Zero and Finite Temperature

abstract:
  We survey recent work on the properties and decays of mesons as bound states
of confined quarks at both zero and finite temperature. The framework for these
investigations is the set of QCD Dyson--Schwinger equations truncated to
ladder-rainbow level. The infrared structure of the ladder-rainbow kernel is
described by two parameters; the ultraviolet behavior is fixed by the one-loop
renormalizaton group behavior of QCD. The work is restricted to the $u$, $d$
and $s$ quark sector and allows a Poincar\'e-covariant study of the masses and
electroweak decay constants of the ground state pseudoscalars and vectors:
$\pi$, $K$, $\rho/\omega$, $K^\star$ and $\phi$. Within the impulse
approximation, we summarize results for the $\pi$ and $K$ charge form factors.
Their timelike behavior exhibits the vector meson production resonances and
from this the associated vector meson strong decay constants are extracted. The
confining property of the quark self-energy dynamically produced in this work
prevents the appearance of spurious $\bar{q}q$ production effects. The finite
temperature behavior of this model, and closely related ones, is summarized
for: the chiral restoration transition, the deconfinement transition, the
$T$-dependence of the spatial meson mode masses, and the $T$-dependence of
selected electroweak and strong decay widths. The $T$-dependence obtained for
meson masses is compared to results from lattice QCD.


title: Fully Self-consistent RPA description of the many level pairing model

abstract:
  The Self-Consistent RPA (SCRPA) equations in the particle-particle channel
are solved without any approximation for the picket fence model. The results
are in excellent agreement with the exact solutions found with the Richardson
method. Particularly interesting features are that screening corrections
reverse the sign of the interaction and that SCRPA yields the exact energies in
the case of two levels with two particles.


title:
Transverse Momentum Distribution of J/Psi's in Pb-Pb Collisions and
  Gluon Rescattering

abstract:
  The transverse momentum dependence of J/Psi suppression in relativistic heavy
ion collisions is calculated from initial state gluon rescattering not only
with nucleons but also with prompt gluons produced in nucleon-nucleon
collisions in the early phase of the reaction. The second mechanism is new and
turns out to be important in a description of the data for central collisions.


title: Low-energy Compton scattering on the nucleon and sum rules

abstract:
  The Gerasimov-Drell-Hearn and Baldin-Lapidus sum rules are evaluated in the
dressed K-matrix model for photon-induced reactions on the nucleon. For the
first time the sum $\alpha+\beta$ of the electric and magnetic polarisabilities
and the forward spin polarisability $\gamma_0$ are explicitly calculated in two
alternative ways -- from the sum rules and from the low-energy expansion of the
real Compton scattering amplitude -- within the {\em same} framework. The two
methods yield compatible values for $\alpha+\beta$ but differ somewhat for
$\gamma_0$. Consistency between the two ways of determining the
polarisabilities is a measure of the extent to which basic symmetries of the
model are obeyed.


title: Triaxial deformation in 10Be

abstract:
  The triaxial deformation in $^{10}$Be is investigated using a microscopic
$\alpha+\alpha+n+n$ model. The states of two valence neutrons are classified
based on the molecular-orbit (MO) model, and the $\pi$-orbit is introduced
about the axis connecting the two $\alpha$-clusters for the description of the
rotational bands. There appear two rotational bands comprised mainly of $K^\pi
= 0^+$ and $K^\pi = 2^+$, respectively, at low excitation energy, where the two
valence neutrons occupy $K^\pi = 3/2^-$ or $K^\pi = 1/2^-$ orbits. The
triaxiality and the $K$-mixing are discussed in connection to the molecular
structure, particularly, to the spin-orbit splitting. The extent of the
triaxial deformation is evaluated in terms of the electro-magnetic transition
matrix elements (Davydov-Filippov model, Q-invariant model), and density
distribution in the intrinsic frame. The obtained values turned out to be
$\gamma = 15^o \sim 20^o$.


title:
Magnetic moment and radius of the nucleon in a nonlocal model of
  meson-nucleon interaction

abstract:
  Magnetic moment and radius of the nucleon are calculated in a nonlocal
extension of the chiral linear \sigma-model. Properties of the nonlocal model
under the vector and axial transformations are considered. The conserved
electromagnetic and vector currents, and partially conserved axial vector
current are obtained. In the calculation of the nucleon electromagnetic vertex
the \pi- and \sigma-loop diagrams are included. Contribution from vector mesons
is added in the vector meson dominance model with a gauge-invariant
photon-meson coupling. The nonlocality parameter associated with the \pi N
interaction is fixed from the experimental magnetic moment of the neutron.
Other parameters (nonlocality parameter for the \sigma N interaction and the
mass of the \sigma-meson) are constrained by the magnetic moment of the proton.
The calculated electric and magnetic mean-square radii of the proton and
neutron are in satisfactory agreement with experiment.


title: Superfluid states with moving condensate in nuclear matter

abstract:
  Superfluid states of symmetric nuclear matter with finite total momentum of
Cooper pairs (nuclear LOFF phase) are studied with the use of Fermi-liquid
theory in the model with Skyrme effective forces. It is considered the case of
four-fold splitting of the excitation spectrum due to finite superfluid
momentum and coupling of T=0 and T=1 pairing channels. It has been shown that
at zero temperature the energy gap in triplet-singlet (TS) pairing channel (in
spin and isospin spaces) for the SkM$^*$ force demonstrates double-valued
behavior as a function of superfluid momentum. As a consequence, the phase
transition at the critical superfluid momentum from the LOFF phase to the
normal state will be of a first order. Behavior of the energy gap as a function
of density for TS pairing channel under increase of superfluid momentum changes
from one-valued to universal two-valued. It is shown that two-gap solutions,
describing superposition of states with singlet-triplet (ST) and TS pairing of
nucleons appear as a result of branching from one-gap ST solution. Comparison
of the free energies shows that the state with TS pairing of nucleons is
thermodynamically most preferable.


title: Caloric curve for finite nuclei in relativistic models

abstract:
  In this work we calculate the caloric curve (excitation energy per particle
as a function of temperature) for finite nuclei within the non--linear Walecka
model for different proton fractions. It is shown that the caloric curve is
sensitive to the proton fraction. Freeze-out volume effects in the caloric
curve are also studied.


title:
Quadrupole Oscillations as Paradigm of the Chaotic Motion in Nuclei.
  Part 2

abstract:
  The present communication is a continuation of the review, the first part of
which was presented in nucl-th/0109033. The second part dealswith the
manifistation of Chaotic dynamics at quantum level. The variations of
statistical properties of energy spectrum in the process of R-C-R transition
have been studied in detail. We proved that the type of the classical motion is
correlated with the structure of the eigenfunctions of highly excited states in
the R-C-R transition. Shell structure destruction induced by the increase of
nonintegrable perturbation was analyzed.


title:
Isospin Dependence of Mechanical and Chemical Instabilities in
  Neutron-Rich Matter

abstract:
  Within nuclear thermodynamics and an isospin-dependent transport model we
investigate respective roles of the nuclear mean field and the 2-body
stochastic scattering on the evolution of density and isospin fluctuations in
either mechanically or chemically unstable regions of neutron-rich matter. It
is found that the mean field dominates overwhelmingly the fast growth of both
fluctuations, while the 2-body scattering influences significantly the later
growth of the isospin fluctuation only. Moreover, both fluctuations grow in
mechanically unstable systems, while only the density fluctuation grows
significantly in chemically unstable ones. Furthermore, the magnitude of both
fluctuations decreases with the increasing isospin asymmetry because of the
larger reduction of the attractive isoscalar mean field by the stronger
repuslive neutron symmetry potential in the more neutron-rich matter. Finally,
several experimental measurements are proposed to test these findings.


title:
Effects of negative energy components in two-body deuteron
  photodisintegratio

abstract:
  Several observables in two-body deuteron photodisintegration are investigated
in the framework of the Bethe-Salpeter formalism. Apart from keeping throughout
Lorentz covariance, a special attention is paid to inclusion of both the
positive energy and negative energy partial-wave components of the deuteron
state. Using the Bethe-Salpeter equation for deuteron in the ladder
approximation with one-boson exchanges as a driving force, the contribution of
the negative energy states is studied for the unpolarized differential cross as
well as the linear photon and tensor target asymmetries. These states are found
to have an impact on the observables and, thus, should be taken into account in
a complete theoretical development of the reaction in the intermediate energy
regime.


title: $\Delta(1232)$ Isobar Excitations and the Ground State of Nuclei

abstract:
  The influence of $\Delta$ isobar components on the ground state properties of
nuclear systems is investigated for nuclear matter as well as finite nuclei.
Many-body wave functions, including isobar configurations, and binding energies
are evaluated employing the framework of the coupled-cluster theory. It is
demonstrated that the effect of isobar configurations depends in a rather
sensitive way on the model used for the baryon-baryon interaction. As examples
for realistic baryon-baryon interactions with explicit inclusion of isobar
channels we use the local ($V28$) and non-local meson exchange potentials
(Bonn$_{2000}$) but also a model recently developed by the Salamanca group,
which is based on a quark picture. The differences obtained for the nuclear
observables are related to the treatment of the interaction, the $\pi$-exchange
contributions in particular, at high momentum transfers.


title: Single particle properties of 16O and 40Ca

abstract:
  We discuss some single particle properties of $^{16}$O and $^{40}$Ca using
correlated basis function theory and Fermi hypernetted chain equations with
central and tensor correlations. In particular, we concentrate on one body
density matrix, momentum distribution, natural orbits and quasi hole states.
The correlations are variationally generated by a realistic hamiltonian
containing the Argonne $v'_{8}$ two-nucleon and Urbana IX three-nucleon
interactions. The correlated momentum distributions show the well known
enhancement at large momenta, with a relative importance of the different
correlations (Jastrow and tensor) similar to that in nuclear matter. The
natural orbits and their occupation numbers are obtained by diagonalization of
the density matrix. The correlated first natural orbits occupations are
depleted by more than 10%, whereas the first following ones are occupied by a
few percent. The spectroscopic factors of the valence states are lowered by
$\sim 8-12%$ with respect to unity by central and tensor correlations,
confirming that short range correlations alone are not able to explain the
values extracted from $(e,e'p)$ experiments.


title: Self-Consistent Separable RPA For Density- and Current-Dependent Forces

abstract:
  Self-consistent factorization of two-body residual interaction is proposed
for arbitrary density- and current-dependent energy functionals. Following this
procedure, a separable RPA (SRPA) method is constructed. SRPA dramatically
simplifies the calculations and demonstrates quick convergence to exact
results. The method is tested for SkM* forces.


title:
Electron helicity-dependence in (e,e'p) reactions with polarized nuclei
  and the fifth response function

abstract:
  The cross section for electron-induced proton knockout reactions with
polarized beam and target is computed in a DWIA model. The analysis is focused
on the electron helicity-dependent (HD) piece of the cross section. For the
case of in-plane emission a new symmetry is found in the HD cross section,
which takes opposite values for specific opposing pairs of nuclear
orientations, explaining why the fifth response (involving polarized electrons,
but unpolarized nuclei) is zero for this choice of kinematics. Even when this
symmetry breaks down in the case of nucleon emission out of the scattering
plane, it is shown that it is still present in the separate response functions.
A physical explanation of these results is presented using a semi-classical
model of the reaction based on the PWIA and on the concept of a nucleon orbit
with its implied expectation values of position and spin.


title:
Chiral dynamics and the reactions pp \to d K^+ \bar{K}^0 and pp \to d
  \pi^+ \eta

abstract:
  We perform a study of the final state interactions of the K^+ \bar{K^0} and
the \bar{K^0}d systems in the reactions pp \to d K^+ \bar{K^0} and pp \to d
\pi^+ \eta. Since the two-meson system couples strongly to the a_0(980)
resonance, these reactions are expected to be an additional source of
information about the controversial scalar sector. We also show that these
reactions present peculiar features which can shed additional light on the much
debated meson-baryon scalar sector with strangeness -1. We deduce the general
structure of the amplitudes close to the d K^+\bar{K}^0 threshold, allowing for
primary K^+ \bar{K^0} as well as \pi^+\eta production with the two mesons in
relative S- or P-wave. The interactions of the mesons are accounted for by
using chiral unitary techniques, which generate dynamically the a_0(980)
resonance, and the \bar{K^0}d interaction is also taken into account. General
formulae are derived that allow to incorporate the final state interactions in
these systems for any model of the production mechanism. We illustrate this
approach by considering two specific production mechanisms based on three
flavor meson-baryon chiral perturbation theory. It is demonstrated that in this
scenario the \bar{K^0}d interactions are very important and can change the
cross section by as much as one order of magnitude. The amount of \pi^+\eta
versus K^+ \bar{K^0} production is shown to depend critically on the primary
mixture of the two mechanisms, with large interference effects due to final
state interactions. These effects are also shown to occur in the event
distributions of invariant masses which are drastically modified by the final
state interactions of the two-meson or the \bar{K}d system.


title: Optical Potentials in Kaonic Atoms

abstract:
  A microscopic optical potential based on a chiral model is used as a starting
point for studying kaonic atoms levels. We add to this potential a
phenomenological part fitted to the experimentally known shifts and widths of
kaonic levels. This fitted potential is used to predict deeply bound atomic
levels, as well as nuclear levels. Comparison with the predictions of other
optical models found in the literature is done. Also the effects on the kaonic
atoms levels of certain known non-local contributions to the optical potential
are also analyzed.


title: Role of Chiral Symmetry in the Nuclear Many-Body Problem

abstract:
  The role of chiral (pion) dynamics in nuclear matter is reviewed.
Contributions to the energy per particle from one- and two-pion exchange are
calculated systematically, and it is demonstrated that already at order $k^4_f$
in the Fermi momentum, two-pion exchange produces realistic nuclear binding
together with very reasonable values for the compressibility and the asymmetry
energy. Further implications of these results are discussed.


title: The $\mu^-d$ capture rate in effective field theory

abstract:
  Muon capture on the deuteron is studied in heavy baryon chiral perturbation
theory (HBChPT). It is found that by far the dominant contribution to $\mu d$
capture comes from a region of the final three-body phase-space in which the
energy of the two neutrons is sufficiently small for HBChPT to be applicable.
The single unknown low-energy constant having been fixed from the tritium beta
decay rate, our calculation contains no free parameter. Our estimate of the
$\mu d$ capture rate is consistent with the existing data. The relation between
$\mu d$ capture and the $\nu d$ reactions, which are important for the SNO
experiments, is briefly discussed.


title: Pion-nucleon scattering in a Bethe-Salpeter approach

abstract:
  A covariant model of elastic pion-nucleon scattering based on the
Bethe-Salpeter equation is presented. We obtain a good description of the S-
and P-wave phase shifts up to 360 MeV laboratory energy. We also compare
results from the K-matrix approach and several 3-dimensional quasipotential
equations to the Bethe-Salpeter equation.


title: Kaon Interferometry: A Sensitive Probe of the QCD Equation of State?

abstract:
  We calculate the kaon HBT radius parameters for high energy heavy ion
collisions, assuming a first order phase transition from a thermalized
Quark-Gluon-Plasma to a gas of hadrons. At high transverse momenta K_T ~ 1
GeV/c direct emission from the phase boundary becomes important, the emission
duration signal, i.e., the R_out/R_side ratio, and its sensitivity to T_c (and
thus to the latent heat of the phase transition) are enlarged. Moreover, the
QGP+hadronic rescattering transport model calculations do not yield unusual
large radii (R_i<9fm). Finite momentum resolution effects have a strong impact
on the extracted HBT parameters (R_i and lambda) as well as on the ratio
R_out/R_side.


title: Effect of particle-phonon coupling on pairing correlations in nuclei

abstract:
  The influence of particle-phonon coupling on pairing correlations in nuclei
is studied by solving the Dyson equation including the anomalous (pairing)
Green function. We develop the formalism for solving the equation with the
minimum of approximations. The solution of the Dyson equation is compared with
the diagonalization of particle-phonon coupled Hamiltonian in a small space.
This comparison reveals that the effect of many-phonon states is incorporated
in the Dyson equation. We calculate the pairing gap of the neutron in 120Sn. We
compare analytically the present method with a simpler treatment based on
Bloch-Horowitz perturbation theory.


title: Double beta decay in deformed nuclei

abstract:
  The pseudo SU(3) approach has been used to describe many low-lying rotational
bands, as well as BE(2) and B(M1) intensities in rare earth and actinide
nuclei, both with even-even and odd-mass numbers . The double beta half lives
of some of these parent nuclei to the ground and excited states of the daughter
ones were evaluated for the two and zero neutrino emitting modes using the
pseudo SU(3) scheme. The predictions were in good agreement with the available
experimental data for 150Nd and 238U.
  The double electron capture half-lives of 156Dy, 162Er and 168Yb were also
studied using the same formalism. The first nuclei was found to be the best
candidate for experimental detection, with a half-life of 10^24 yr to the first
excited 0+ state in 156Gd. There are strong selection rules which restrict the
two neutrino mode of the double beta decay in some other nuclei, including
160Gd. Experimental limits for the double beta decay of 160Gd have been
reported . Recently it was argued that the strong cancellation of the 2nu mode
in the double beta decay of 160Gd would suppress the background for the
detection of the 0nu mode.
  In the present contribution we extend the previous research evaluating the
double beta half lives of 160Gd using the pseudo SU(3) model. While the 2nu
mode is forbidden when the most probable occupations are considered, states
with different occupation numbers can be mixed through the pairing interaction.
The amount of this mixing is evaluated using perturbation theory. The
possibility of observing the double beta decay in 160Gd is discussed for both
the 2nu and 0nu modes.


title: Pairing and continuum effects in nuclei close to the drip line

abstract:
  The Hartree-Fock-Bogoliubov (HFB) equations in coordinate representation are
solved exactly, i.e., with correct asymptotic boundary conditions for the
continuous spectrum. The calculations are preformed with effective Skyrme
interactions. The exact HFB solutions are compared with HFB calculations based
on box boundary conditions and with resonant continuum Hartree-Fock-BCS
(HF-BCS) results. The comparison is done for the neutron-rich Ni isotopes. It
is shown that close to the drip line the amount of pairing correlations depends
on how the continuum coupling is treated. On the other hand, the resonant
continuum HF-BCS results are generally close to those of HFB even in
neutron-rich nuclei.


title: Low Momentum Nucleon-Nucleon Interaction and Fermi Liquid Theory

abstract:
  We use the induced interaction of Babu and Brown to derive two novel
relations between the quasiparticle interaction in nuclear matter and the
unique low momentum nucleon-nucleon interaction V_low k in vacuum. These
relations provide two independent constraints on the Fermi liquid parameters of
nuclear matter. We derive the full renormalization group equations in the
particle-hole channels from the induced interaction. The new constraints,
together with the Pauli principle sum rules, define four combinations of Fermi
liquid parameters that are invariant under the renormalization group flow.
Using empirical values for the spin-independent Fermi liquid parameters, we are
able to compute the major spin-dependent ones by imposing the new constraints
and the Pauli principle sum rules. The effects of tensor forces are discussed.


title: Monopoles and Knots in Skyrme Theory

abstract:
  We show that the Skyrme theory actually is a theory of monopoles which allows
a new type of solitons, the topological knots made of monopole-anti-monopole
pair,which is different from the well-known skyrmions. Furthermore, we derive a
generalized Skyrme action from the Yang-Mills action of QCD, which we propose
to be an effective action of QCD in the infra-red limit. We discuss the
physical implications of our results.


title:
Extension of random-phase approximation preserving energy weighted sum
  rules: an application to a 3-level Lipkin model

abstract:
  A limitation common to all extensions of random-phase approximation including
only particle-hole configurations is that they violate to some extent the
energy weighted sum rules. Considering one such extension, the improved RPA
(IRPA), already used to study the electronic properties of metallic clusters,
we show how it can be generalized in order to eliminate this drawback. This is
achieved by enlarging the configuration space, including also elementary
excitations corresponding to the annihilation of a particle (hole) and the
creation of another particle (hole) on the correlated ground state. The
approach is tested within a solvable 3-level model.


title:
Event-by-Event Analysis of Proton-Induced Nuclear Multifragmentation:
  Determination of Phase Transition Universality-Class in System with Extreme
  Finite-Size Constraints

abstract:
  A percolation model of nuclear fragmentation is used to interpret 10.2 GeV/c
p+197Au multi-fragmentation data. Emphasis is put on finding signatures of a
continuous nuclear matter phase transition in finite nuclear systems. Based on
model calculations, corrections accounting for physical constraints of the
fragment detection and sequential decay processes are derived. Strong
circumstantial evidence for a continuous phase transition is found, and the
values of two critical exponents, sigma = 0.5+-0.1 and tau = 2.35+-0.05, are
extracted from the data. A critical temperature of T_c = 8.3+-0.2 MeV is found.


title: Transverse Expansion and High $p_T$ Azimuthal Asymmetry at RHIC

abstract:
  Rapid 3+1D transverse plus Bjorken collective expansion in $A+A$ collisions
at ultra-relativistic energies is shown to reduce substantially the azimuthal
asymmetry resulting from jet quenching. While the azimuthal asymmetry in
non-central collisions, $v_2(p_T>2 \rm{GeV/c})\sim 0.15$ reported by STAR at
RHIC, can be accounted for by spatially anisotropic jet energy loss through a
1+1D expanding gluon plasma with $dN^g/dy\sim 1000$, we show that if rapid
transverse collective expansion of the plasma is assumed, then the asymmetry
due to jet quenching may be reduced below the observed level. Possible
implications of this effect are discussed.


title:
An Analysis of the $^{12}$C+$^{24}$Mg Reaction Using A New Coupling
  Potential

abstract:
  We introduce a new coupling potential to explain the experimental data for
the $^{12}$C+$^{24}$Mg system at numerous energies in the laboratory system
from 16.0 MeV to 24.0 MeV. This new coupled-channels based approach involves
replacing the usual first derivative coupling potential by a new,
second-derivative coupling potential. This paper first shows and discusses the
limitation of the standard coupled-channels theory in the case where one of the
nuclei in the reaction is strongly deformed. Then, this new approach is shown
to improve consistently the agreement with the experimental data and has made
major improvement on all the previous coupled-channels calculations for this
system.


title: Chiral dynamics in few-nucleon systems

abstract:
  We report on recent progress achieved in calculating various few-nucleon
low-energy observables from effective field theory. Our discussion includes
scattering and bound states in the 2N, 3N and 4N systems and isospin violating
effects in the 2N system. We also establish a link between the nucleon-nucleon
potential derived in chiral effective field theory and various modern
high-precision potentials.


title: Proton-Deuteron Elastic Scattering from 2.5 to 22.5 MeV

abstract:
  We present the results of a calculation of differential cross sections and
polarization observables for proton-deuteron elastic scattering, for proton
laboratory energies from 2.5 to 22.5 MeV. The Paris potential parametrisation
of the nuclear force is used. As solution method for the charged-composite
particle equations the 'screening and renormalisation approach' is adopted
which allows to correctly take into account the Coulomb repulsion between the
two protons. Comparison is made with the precise experimental data of Sagara et
al. [Phys. Rev. C 50, 576 (1994)] and of Sperison et al. [Nucl. Phys. A422, 81
(1984)].


title: Inter-band B(E2) transition strengths in odd-mass heavy deformed nuclei

abstract:
  Inter-band B(E2) transition strengths between different normal parity bands
in 163Dy and 165Er are described using the pseudo-SU(3) model. The Hamiltonian
includes Nilsson single-particle energies, quadrupole-quadrupole and pairing
interactions with fixed, parametrized strengths, and three extra rotor terms
used to fine tune the energy spectra. In addition to inter-band transitions,
the energy spectra and the ground state intra-band B(E2) strengths are
reported. The results show the pseudo-SU(3) shell model to be a powerful
microscopic theory for a description of the normal parity sector in heavy
deformed odd-A nuclei.


title: Analysis of ordinary and radiative muon capture in liquid hydrogen

abstract:
  A simultaneous analysis is made of the measured rates of ordinary muon
capture (OMC) and radiative muon capture (RMC) in liquid hydrogen, using
theoretical estimates for the relevant atomic capture rates that have been
obtained in chiral perturbation theory with the use of the most recent values
of the coupling constants. We reexamine the basic formulas for relating the
atomic OMC and RMC rates to the liquid-hydrogen OMC and RMC rates,
respectively. Although the analysis is significantly influenced by ambiguity in
the molecular state population, we can demonstrate that, while the OMC data can
be reproduced, the RMC data can be explained only with unrealistic values of
the coupling constants; the degree of difficulty becomes even more severe when
we try to explain the OMC and RMC data simultaneously.


title: Structure of the proton drip line nucleus $^{17}$F

abstract:
  The odd $A$ proton drip line nucleus $^{17}$F has been studied in a
semi-microscopic model which couples proton quasiparticle motion to the
vibrational motion of the neighbouring even-even $^{18}$Ne core. The
experimentally observed low lying excitation spectrum, electric quadrupole
moment, magnetic dipole moment, $B(E1)$ and $B(E2)$ values have been fairly
well reproducd. The calculated rms radius of the first excited state is well
reproduced and is found to be larger than that of the ground state which agrees
with the experimental observation.


title: Few-Nucleon Calculations and Correlations

abstract:
  Some present day results for few-nucleon bound state, two-nucleon correlation
functions and scattering observables are briefly reviewed. The old idea of the
Coulomb sum rule as a way to extract the pp correlation function is
reconsidered. It appears to be an ideal case to probe properties of the density
operator and the ground state wave functions without disturbances of final
state interactions (FSI) in exclusive electron scattering on 3He. Also
exclusive photodisintegration of 3He is regarded which appears to be promising
to identify 3N force effects.


title: Chiral 2$\pi$-exchange NN-potentials: Relativistic $1/M^2$-Corrections

abstract:
  We calculate in baryon chiral perturbation theory the relativistic
$1/M^2$-corrections to the leading order two-pion exchange diagrams. We give
explicit expressions for the corresponding one-loop NN-amplitudes in momentum
space. The resulting isovector central and isoscalar spin-spin and tensor
NN-amplitudes involve non-static terms proportional to the squared nucleon
center-of-mass momentum $p^2$. From the two-pion exchange box diagrams we
obtain an isoscalar quadratic spin-orbit NN-amplitude. We give also analytical
expressions for the corresponding NN-potentials in coordinate space. The
diagrammatic results presented here make the chiral NN-potential complete at
next-to-next-to-next-to-leading order.


title: Hyperon-nucleon scattering and hyperon masses in the nuclear medium

abstract:
  We analyze low-energy hyperon-nucleon scattering using an effective field
theory in next-to-leading order. By fitting experimental cross sections for
laboratory hyperon momenta below 200 MeV/c and using information from the
hypertriton we determine twelve contact-interaction coefficients. Based on
these we discuss the low-density expansion of hyperon mass shifts in the
nuclear medium.


title: Contact pairing interaction for the Hartree-Fock-Bogoliubov calculations

abstract:
  Properties of density-dependent contact pairing interactions in nuclei are
discussed. It is shown that the pairing interaction that is intermediate
between surface and volume pairing forces gives the pairing gaps that are
compatible with the experimental odd-even mass staggering. Results of the
deformed Hartree-Fock-Bogoliubov calculations for this `mixed' pairing
interaction, and using the transformed harmonic oscillator basis, are
presented.


title: Charge-Symmetry Violation in Pion Scattering from Three-Body Nuclei

abstract:
  We discuss the experimental and theoretical status of charge-symmetry
violation (CSV) in the elastic scattering of pi+ and pi- on 3H and 3He.
Analysis of the experimental data for the ratios r1, r2, and R at Tpi = 142,
180, 220, and 256 MeV provides evidence for the presence of CSV. We describe
pion scattering from the three-nucleon system in terms of single- and
double-scattering amplitudes. External and internal Coulomb interactions as
well as the Delta-mass splitting are taken into account as sources of CSV.
Reasonable agreement between our theoretical calculations and the experimental
data is obtained for Tpi = 180, 220, and 256 MeV. For these energies, it is
found that the Delta-mass splitting and the internal Coulomb interaction are
the most important contributions for CSV in the three-nucleon system. The CSV
effects are rather sensitive to the choice of pion-nuclear scattering
mechanisms, but at the same time, our theoretical predictions are much less
sensitive to the choice of the nuclear wave function. It is found, however,
that data for r2 and R at Tpi = 142 MeV do not agree with the predictions of
our model, which may indicate that there are additional mechanisms for CSV
which are important only at lower energies.


title: Probing Mechanical and Chemical Instabilities in Neutron-Rich Matter

abstract:
  The isospin-dependence of mechanical and chemical instabilities is
investigated within a thermal and nuclear transport model using a Skyrme-type
phenomenological equation of state for neutron-rich matter. Respective roles of
the nuclear mean field and the 2-body stochastic scattering on the evolution of
density and isospin fluctuations in either mechanically or chemically unstable
regions of neutron-rich matter are investigated. It is found that the mean
field dominates overwhelmingly the fast growth of both fluctuations, while the
2-body scattering influences significantly the later growth of the isospin
fluctuation only. The magnitude of both fluctuations decreases with the
increasing isospin asymmetry because of the larger reduction of the attractive
isoscalar mean field by the stronger repuslive neutron symmetry potential in
the more neutron-rich matter. Moreover, it is shown that the isospin
fractionation happens later, but grows faster in the more neutron-rich matter.
Implications of these results to current experiments exploring properties of
neutron-rich matter are discussed.


title:
Probing equilibration with respect to isospin degree of freedom in
  intermediate energy heavy ion collisions

abstract:
  We have studied equilibration with respect to isospin degree of freedom in
four 96 mass systems $^{96}Ru+^{96}Ru$, $^{96}Ru+^{96}Zr$,
  $^{96}Zr+^{96}Ru$, $^{96}Zr+^{96}Zr$ at 100 AMeV and 400 AMeV with isospin
dependent QMD.
  We propose that the neutron-proton differential rapidity distribution is a
sensitive probe to the degree of equilibration with respect to the isospin
degree of freedom. By analyzing the average $N/Z$ ratio of emitted nucleons,
light charged particles (LCP) and intermediate mass fragments (IMF), it is
found that there exist memory effect in multifragmentation process. The average
$N/Z$ ratio of IMF reduces largely as beam energy increases from 100 AMeV to
400 AMeV which may result from the change of the behavior of the isotope
distribution of IMF charges. The isotope distribution of IMF charges does also
show certain memory effect at 100 AMeV case but not at 400 AMeV case.


title:
Recent Developments in relativistic models for exclusive (e,e'p)
  reactions

abstract:
  A comparison of impulse approximation calculations for the (e,e'p) reaction,
based on the Dirac equation and the Schrodinger one is presented. Trivial
(kinematics) differences are indicated, as well as how to remove them from the
standard nonrelativistic formalism. Signatures of the relativistic approach are
found where the enhancement of the lower components (spinor distortion or
negative energy contributions) modifies TL observables with respect to the
nonrelativistic predictions, what seems to be confirmed by the experiment.
Finally, the relativistic approach is used to analyze several experiments for
the reaction 16O(e,e'p)15N taken at values of Q^2 from 0.2 to 0.8 (GeV/c)^2,
not finding a significant Q^2 dependence of the scale factors over this range.


title: Observing Spontaneous Strong Parity Violation in Heavy-Ion Collisions

abstract:
  We discuss the problem of observing spontaneous parity and CP violation in
collision systems. We discuss and propose observables which may be used in
heavy-ion collisions to observe such violations, as well as event-by-event
methods to analyze the data. Finally, we discuss simple monte-carlo models of
these CP violating effects which we have used to develop our techniques and
from which we derive rough estimates of sensitivities to signals which may be
seen at RHIC.


title:
Calculation of the number of partitions with constraints on the fragment
  size

abstract:
  This article introduces recursive relations allowing the calculation of the
number of partitions with constraints on the minimum and/or on the maximum
fragment size.


title:
Extended van Royen-Weisskopf formalism for lepton-antilepton meson decay
  widths within non-relativistic quark models

abstract:
  The classical van Royen-Weisskopf formula for the decay width of a meson into
a lepton-antilepton pair is modified in order to include non-zero quark
momentum contributions within the meson as well as relativistic effects.
Besides, a phenomenological electromagnetic density for quarks is introduced.
The meson wave functions are obtained from two different models: a chiral
constituent quark model and a quark potential model including instanton
effects. The modified van Royen-Weisskopf formula is found to improve
systematically the results for the widths, giving an overall good description
of all known decays.


title: Statistical Modeling of Nuclear Systematics

abstract:
  Statistical modeling of data sets by neural-network techniques is offered as
an alternative to traditional semiempirical approaches to global modeling of
nuclear properties. New results are presented to support the position that such
novel techniques can rival conventional theory in predictive power, if not in
economy of description. Examples include the statistical inference of atomic
masses and beta-decay halflives based on the information contained in existing
databases. Neural network modeling, as well as other statistical strategies
based on new algorithms for artificial intelligence, may prove to be a useful
asset in the further exploration of nuclear phenomena far from stability.


title: The $^{10}$Li spectrum and the $^{11}$Li properties

abstract:
  The neutron--$^9$Li interaction and the corresponding low-energy $^{10}$Li
spectrum are decisive for the properties of $^{11}$Li described as a three-body
system (n+n+$^{9}$Li). We compute structure and breakup properties of $^{11}$Li
as function of this interaction. The hyperfine structure due to the spin 3/2 of
both $^{9}$Li and $^{11}$Li is needed and treated with special care. We use the
hyperspherical adiabatic expansion of the Faddeev equations for the structure
and the participant-spectator model for the breakup reactions of $^{11}$Li. We
use established experimental constraints of both $^{11}$Li (binding energy,
size and differential breakup cross sections) and of $^{10}$Li (a virtual
s-state below 50 keV and a $p$-resonance around 0.54 MeV).Another $p$-resonance
must then be present below 0.54 MeV and another $s$-level must be present
between about 0.5 MeV and 1 MeV depending on unknown spin assignments. All
established facts are in agreement with our predictions obtained within the
same consistent model.


title: Local Density Approximation for Pairing Correlations in Nuclei

abstract:
  We introduce a natural and simple to implement renormalization scheme of the
Hartree-Fock-Bogoliubov (HFB) equations for the case of zero range pairing
interaction. This renormalization scheme proves to be equivalent to a simple
energy cut-off with a position or density dependent running coupling constant.
Subsequently, we present self-consistent HFB calculations with a full
consideration of the continuum of long chains of spherical tin and lead nuclei
(essentially from one drip line to another) using the SLy5 interaction. In the
pairing channel we use a zero range interaction, treated by means of this new
regularization scheme.


title:
Parity-Violating Interaction Effects I: the Longitudinal Asymmetry in pp
  Elastic Scattering

abstract:
  The proton-proton parity-violating longitudinal asymmetry is calculated in
the lab-energy range 0--350 MeV, using a number of different, latest-generation
strong-interaction potentials--Argonne V18, Bonn-2000, and Nijmegen-I--in
combination with a weak-interaction potential consisting of rho- and
omega-meson exchanges--the model known as DDH. The complete scattering problem
in the presence of parity-conserving, including Coulomb, and parity-violating
potentials is solved in both configuration- and momentum-space. The predicted
parity-violating asymmetries are found to be only weakly dependent upon the
input strong-interaction potential adopted in the calculation. Values for the
rho- and omega-meson weak coupling constants $h^{pp}_\rho$ and $h^{pp}_\omega$
are determined by reproducing the measured asymmetries at 13.6 MeV, 45 MeV, and
221 MeV.


title: Analysis of Pion Electroproduction Data

abstract:
  A fit to the existing pion electroproduction data is presented. This work
builds upon our previous analyses of pion photoproduction and elastic
pion-nucleon scattering over the Delta resonance region. We comment on the
extraction of E_1+ ^3/2 / M_1+ ^3/2 (E2/M1) and S_1+ ^3/2 / M_1+ ^3/2 (S2/M1)
ratios, and note that the E2/M1 ratio approaches, and possibly crosses, zero
below a Q2 of 5 (GeV/c}^2.


title:
Doorway states for one-nucleon transfer reactions as a test for current
  approaches to nuclei

abstract: The naturalness concept of the effective field theory is not confirmed.


title: Tensor representation of the nucleon-nucleon amplitude

abstract:
  Many approaches to nucleon-nucleus elastic and inelastic scattering are based
on the use of the free-space nucleon-nucleon transition amplitude. In
calculations where the full spin-dependence of this amplitude is needed, its
use is more tractable when it is expressed in terms of irreducible tensor
operators of the spins of the interacting nucleons. We present general formulae
for this representation which is particularly useful for inelastic scattering
studies involving spin-flip transitions of a target nucleon.


title: Dissociation of a Heavy Quarkonium at High Temperatures

abstract:
  We examine three different ways a heavy quarkonium can dissociate at high
temperatures. The heavy quarkonium can dissociate spontaneously when it becomes
unbound at a temperature above its dissociation temperature. Following the
recent work of Digal, Petreczky, and Satz, we calculate the dissociation
temperatures of heavy quarkonia taking into account the angular momentum
selection rules and using a temperature-dependent potential inferred from
lattice gauge calculations. We find that the selection rules change the
dissociation temperatures substantially for charmonia but only slightly for
bottomia. A quarkonium system in thermal equilibrium with the medium can
dissociate by thermalization. The fraction of quarkonium lying above the
dissociation threshold increases as temperature increases. A quarkonium can
also dissociate by colliding with light hadrons. We evaluate the cross sections
for the dissociation of $J/\psi$ and $\Upsilon$ in collision with $\pi$ as a
function of the temperature of the hadron medium, using the quark-interchange
model of Barnes and Swanson. We find that as the temperature increases, the
threshold energy decreases and the dissociation cross section increases.


title:
Temperature dependence of rho- and a_1-meson masses and mixing of vector
  and axial-vector correlators

abstract:
  Within a chiral model which provides a good description of the properties of
rho and a_1 mesons in vacuum, it is shown that, to order T^2, the rho- and
a_1-meson masses remain constant in the chiral limit, even if at tree level
they are proportional to the chiral condensate, sigma_0. Numerically, the
temperature dependence of the masses turns out to be small also for realistic
parameter sets and high temperatures. The weak temperature dependence of the
masses is consistent with the Eletsky-Ioffe mixing theorem, and traces of
mixing effects can be seen in the spectral function of the vector correlator at
finite temperature.


title: Dispersion Effects in Nucleon Polarisabilities

abstract:
  We present a formalism to extract the dynamical nucleon polarisabilities
defined via a multipole expansion of the structure amplitudes in nucleon
Compton scattering. In contradistinction to the static polarisabilities,
dynamical polarisabilities gauge the response of the internal degrees of
freedom of a composed object to an external, real photon field of arbitrary
energy. Being energy dependent, they therefore contain additional information
about dispersive effects induced by internal relaxation mechanisms, baryonic
resonances and meson production thresholds of the nucleon. We give explicit
formulae to extract the dynamical electric and magnetic dipole as well as
quadrupole polarisabilities from low energy nucleon Compton scattering up to
the one pion production threshold and discuss the connection to the definition
of static nucleon polarisabilities. As a concrete example, we examine the
results of leading order Heavy Baryon Chiral Perturbation Theory for the four
leading spin independent iso-scalar polarisabilities of the nucleon. Finally,
we consider the possible r{\^o}le of energy dependent effects in low energy
extractions of the iso-scalar dipole polarisabilities from Compton scattering
on the deuteron.


title: Non-abelian anomaly and the Lagrangian for radiative muon capture

abstract:
  We discuss an anomalous Lagrangian of the pi-rho-omega-a_1 system in the
presence of external electroweak fields which is suitable for constructing the
amplitude for the radiative muon capture by proton.


title:
Light Lambda-Lambda Hypernuclei and the Onset of Stability for Lambda-Xi
  Hypernuclei

abstract:
  New Faddeev-Yakubovsky calculations for light Lambda-Lambda hypernuclei are
presented in order to assess the self consistency of the Lambda-Lambda
hypernuclear binding-energy world data and the implied strength of the
Lambda-Lambda interaction, in the wake of recent experimental reports on
Lambda-Lambda-4H and Lambda-Lambda-6He. Using Gaussian soft-core simulations of
Nijmegen one-boson-exchange model interactions, the Nijmegen soft-core model
NSC97 simulations are found close to reproducing the recently reported binding
energy of Lambda-Lambda-6He, but not those of other species. For stranger
systems, Faddeev calculations of light Lambda-Xi hypernuclei, using a
simulation of the strongly attractive Lambda-Xi interactions due to the same
model, suggest that Lambda-Xi-6He marks the onset of nuclear stability for Xi
hyperons.


title:
Hydrodynamical analysis of hadronic spectra in the 130 GeV/nucleon Au+Au
  collisions

abstract:
  We study one-particle spectra and a two-particle correlation function in the
  130 GeV/nucleon Au+Au collisions at RHIC by making use of a hydrodynamical
model. We calculate the one-particle hadronic spectra and present the first
analysis of Bose-Einstein correlation functions based on the numerical solution
of the hydrodynamical equations which takes both longitudinal and transverse
expansion into account appropriately. The hydrodynamical model provides
excellent agreement with the experimental data in the pseudorapidity and the
transverse momentum spectra of charged hadrons, the rapidity dependence of
anti-proton to proton ratio, and almost consistent result for the pion
Bose-Einstein correlation functions. Our numerical solution with simple
freeze-out picture suggests the formation of the quark-gluon plasma with large
volume and low net-baryon density.


title:
Applications of semiempirical shell model masses based on proton magic
  number Z = 126 to superheavy nuclei

abstract:
  A recently published highly extrapolatable semiempirical shell model mass
equation is shown to describe rather well the energies of several seemingly
well identified alpha-decay chains with known end product nuclei observed in
superheavy elements research. The equation is also applied to the
interpretation problem of some recent hot fusion-evaporation experiments with
unknown end products and several conceivable reaction channels. Some plausible
interpretations are indicated.


title:
Nuclear Effects on Bremsstrahlung Neutrino Rates of Astrophysical
  Interest

abstract:
  We calculate in this work the rates for the neutrino pair production by
nucleon-nucleon bremsstrahlung taking into account the full contribution from a
nuclear one-pion-exchange potential. It is shown that if the temperatures are
low enough ($T \leq 20 MeV$), the integration over the nuclear part can be done
for the general case, ranging from the completely degenerate (D) to the
non-degenerate (ND) regime. We find that the inclusion of the full nuclear
contribution enhances the neutrino pair production by $nn$ and $pp$
bremsstrahlung by a factor of about two in both the D and ND limits when
compared with previous calculations. This result may be relevant for the
physical conditions of interest in the semitransparent regions near the
neutrinosphere in type II supernovae, cooling of neutron stars and other
astrophysical situations.


title: Nuclear polarization in hydrogenlike $^{208}_{~82}$Pb$^{81+}$

abstract:
  We calculate nuclear-polarization energy shifts for hydrogenlike
$^{208}_{~82}$Pb$^{81+}$. A retarded transverse part as well as the Coulomb
part is taken into account as the electromagnetic interaction between an
electron and the nucleus. With a finite charge distribution for the nuclear
ground state and the random-phase approximation to describe the nuclear
excitations, we obtain nuclear polarization energy of the $1s_{1/2}$ state as
--38.2 (--37.0) meV in the Feynman (Coulomb) gauge. For the $2s_{1/2}$,
$2p_{1/2}$ and $2p_{3/2}$ states, they are --6.7 (--6.4), --0.2 (--0.2) and
+0.0 (+0.0) meV, respectively. The seagull term in the two-photon exchange
diagrams is shown to be quite important to obtain the gauge invariance of the
nuclear polarization energies.


title: Subthreshold phi-meson production in heavy-ion collisions

abstract:
  Within a transport code of BUU type the production of phi-mesons in the
reactions Ni+Ni at 1.93 AGeV and Ru+Ru at 1.69 AGeV is studied. New elementary
reaction channels rho+N(Delta) to phi+N and pi+N(1520) to phi+N are included.
In spite of a substantial increase of the \phi multiplicities by these channels
the results stay below the tentative numbers extracted from experimental data.


title: Alpha cluster condensation in 12C and 16O

abstract:
  A new $\alpha$-cluster wave function is proposed which is of the
$\alpha$-particle condensate type. Applications to $^{12}$C and $^{16}$O show
that states of low density close to the 3 resp. 4 $\alpha$-particle threshold
in both nuclei are possibly of this kind. It is conjectured that all
self-conjugate 4$n$ nuclei may show similar features.


title: The deuteron: a mini-review

abstract:
  We review some recent results for elastic electron deuteron scattering
(deuteron form factors) and photodisintegration of the deuteron, with emphasis
on the recent high energy data from Jefferson Laboratory (JLab).


title: How the quark self-energy affects the color-superconducting gap

abstract:
  We consider color superconductivity with two flavors of massless quarks which
form Cooper pairs with total spin zero. We solve the gap equation for the
color-superconducting gap parameter to subleading order in the QCD coupling
constant $g$ at zero temperature. At this order in $g$, there is also a
previously neglected contribution from the real part of the quark self-energy
to the gap equation. Including this contribution leads to a reduction of the
color-superconducting gap parameter $\f_0$ by a factor $b_0'=\exp \big[ -(\p
^2+4)/8 \big]\simeq 0.177$. On the other hand, the BCS relation $T_c\simeq
0.57\f_0$ between $\f_0$ and the transition temperature $T_c$ is shown to
remain valid after taking into account corrections from the quark self-energy.
The resulting value for $T_c$ confirms a result obtained previously with a
different method.


title:
Relativisitic mean field theory of surface pion condensation in finite
  nuclei

abstract:
  We study the possible occurrence of surface pion condensation in finite
nuclei in the relativistic mean field (RMF) theory. We are led to this
conjecture due to the essential role of pions in few-body systems and the
recent (p,n) experiments performed at RCNP for spin-isospin excitations of
medium and heavy nuclei. We calculate explicitly various N=Z closed shell
nuclei with finite pion mean field in the RMF framework and demonstrate the
actual occurrence of surface pion condensation.


title: BBGKY Hierarchy in Scalar QFT

abstract:
  This work is dedicated to obtaining of analog of Bogoliubov's chain for the
case of complex scalar field in QFT and renormalization problem of obtained
equations is discussed.


title: Nonlocality of the NN interaction in an effective field theory

abstract:
  We investigate low energy nucleon dynamics in the effective field theory
(EFT) of nuclear forces. In leading order of the two-nucleon EFT we show that
nucleon dynamics is governed by the generalized dynamical equation with a
nonlocal-in-time interaction operator. This equation is shown to open new
possibilities for applying the EFT approach to the description of low energy
nucleon dynamics.


title:
Geometric relation between centrality and the impact parameter in
  relativistic heavy-ion collisions

abstract:
  We show, under general assumptions which are well satisfied in relativistic
heavy-ion collisions, that the geometric relation of centrality c to the impact
parameter b, namely c ~ pi b^2/sigma_inel, holds to a very high accuracy for
all but most peripheral collisions. More precisely, if c(N) is the centrality
of events with the multiplicity higer than N, then b is the value of the impact
parameter for which the average multiplicity <n(b)> is equal to N. The
corrections to this geometric formula are of the order (Delta n(b)/<n(b)>)^2,
where Delta n(b) is the width of the multiplicity distribution at a given value
of b, hence are very small. In other words, the centrality effectively measures
the impact parameter.


title: Pseudospin symmetry as a relativistic dynamical symmetry in the nucleus

abstract:
  Pseudospin symmetry in nuclei is investigated by solving the Dirac equation
with Woods-Saxon scalar and vector radial potentials, and studying the
correlation of the energy splittings of pseudospin partners with the nuclear
potential parameters. The pseudospin interaction is related to a
pseudospin-orbit term that arises in a Schroedinger-like equation for the lower
component of the Dirac spinor. We show that the contribution from this term to
the energy splittings of pseudospin partners is large. The near pseudospin
degeneracy results from a significant cancelation among the different terms in
that equation, manifesting the dynamical character of this symmetry in the
nucleus. We analyze the isospin dependence of the pseudospin symmetry and find
that its dynamical character is behind the different pseudospin splittings
observed in neutron and proton spectra of nuclei.


title: A kinetic approach to eta' production from a CP-odd phase

abstract:
  The production of (eta,eta')- mesons during the decay of a CP-odd phase is
studied within an evolution operator approach. We derive a quantum kinetic
equation starting from the Witten-DiVecchia-Veneziano Lagrangian for
pseudoscalar mesons containing a U_A(1) symmetry breaking term. The non-linear
vacuum mean field for the flavour singlet pseudoscalar meson is treated as a
classical, self-interacting background field with fluctuations assumed to be
small. The numerical solution provides the time evolution of momentum
distribution function of produced eta'- mesons after a quench at the
deconfinement phase transition. We show that the time evolution of the momentum
distribution of the produced mesons depend strongly on the shape of the
effective potential at the end of the quench, exhibiting either parametric or
tachyonic resonances. Quantum statistical effects are essential and lead to a
pronounced Bose enhancement of the low momentum states.


title: Theoretical description of the double beta decay of 160Gd

abstract:
  The half-life of the 2 neutrino double-beta-decay of 160Gd, a process which
was previously reported as theoretically forbidden, is estimated by including
the pairing interaction, which mixes different occupations and opens channels
for the decay. Explicit expressions are presented for the pairing mixing, and
for the 2 nu and 0 nu double-beta-decay nuclear matrix elements in the present
pseudo SU(3) approach. The estimated double-beta-decay half-lives suggest that
the planned experiments would succeed in detecting the 2 nu double-beta-decay
in 160Gd, and in putting competitive limits for the zero neutrino mode.


title: Structure Functions of Unstable Lithium Isotopes

abstract:
  We study both the spin-average and spin-dependent structure functions of the
lithium isotopes, $^{6-11}$Li, which could be measured at RIKEN and other
nuclear facilities in the future. It is found that the light-cone momentum
distribution of the valence neutron in the halo of $^{11}$Li is very sharp and
symmetric around y = 1, because of the weak binding. The EMC ratios for Li
isotopes are then calculated. We study the possibility of extracting the
neutron structure function from data for the nuclear structure functions of the
Li isotopes. Next we calculate the spin-dependent structure functions of
$^{7,9,11}$Li isotopes, which have spin of 3/2. The effect of the nuclear
binding and Fermi motion on the multipole spin structure function,
$^{3/2}_{~1}g_1$, is about 10% in the region x < 0.7, but it becomes quite
important at large x. The spin structure function of $^{3/2}_{~3}g_1$ is also
investigated. Finally, we discuss the modification of the Gottfried and Bjorken
integrals in a nuclear medium and point out several candidates for a pair of
mirror nuclei to study the flavor-nonsinglet quark distributions in nuclei.


title: Nuclear masses: evidence of order-chaos coexistence

abstract:
  Shell corrections are important in the determination of nuclear ground-state
masses and shapes. Although general arguments favor a regular single-particle
dynamics, symmetry-breaking and the presence of chaotic layers cannot be
excluded. The latter provide a natural framework that explains the observed
differences between experimental and computed masses.


title: Neutrino propagation in Neutron Matter and the Nuclear Equation of State

abstract:
  We study the propagation of neutrinos inside dense matter under the
conditions prevailing in a proto-neutron star. Equations of state obtained with
different nuclear effective interactions (Skyrme type and Gogny type) are first
discussed. It is found that for many interactions, spin and/or isospin
instabilities occur at densities larger than the saturation density of nuclear
matter. From this study we select two representative interactions, SLy230b and
D1P. We calculate the response functions in pure neutron matter where nuclear
correlations are described at the Hartree-Fock plus RPA level. These response
functions allow us to evaluate neutrino mean free paths corresponding to
neutral current processes.


title:
Lambda^0 polarization as a probe for production of deconfined matter in
  ultra-relativistic heavy-ion collisions

abstract:
  We study the polarization change of Lambda^0's produced in ultra-relativistic
heavy-ion collisions with respect to the polarization observed in proton-proton
collisions as a signal for the formation of a Quark-Gluon Plasma (QGP).
Assuming that, when the density of participants in the collision is larger than
the critical density for QGP formation, the Lambda^0 production mechanism
changes from recombination type processes to the coalescence of free valence
quarks, we find that the Lambda^0 polarization depends on the relative
contribution of each process to the total number of Lambda^0's produced in the
collision. To describe the polarization of Lambda^0's in nuclear collisions for
densities below the critical density for the QGP formation, we use the
DeGrand-Miettinen model corrected for the effects introduced by multiple
scattering of the produced Lambda^0 within the nuclear environment.


title: Covariant meson-exchange model of the anti-kaon nucleon interaction

abstract:
  A covariant meson-exchange model of the anti-kaon nucleon interaction within
the framework of the Bethe-Salpeter equation is presented. With just one free
parameter we are able to get a good description of the available experimental
data from below threshold to 300 MeV laboratory momentum.


title: Formation of superheavy elements in heavy-ion collisions

abstract:
  The cold fusion reactions related to 208Pb and 209Bi targets leading to
superheavy elements (SHE) with Z=104-112 have been successfully considered in
our model recently. Here we briefly discuss this model and extend our
consideration to fusion reactions between similar target and projectile. The
reactions between weakly deformed target close to Pb and 76Ge, 82Se projectiles
are also studied. The available experimental cross-sections are well described.
The nucleus-nucleus interaction potential for reactions leading to SHEs are
shortly discussed.


title: Partial Dynamical Symmetry in the Symplectic Shell Model

abstract:
  We present an example of a partial dynamical symmetry (PDS) in an interacting
fermion system and demonstrate the close relationship of the associated
Hamiltonians with a realistic quadrupole-quadrupole interaction, thus shedding
new light on this important interaction. Specifically, in the framework of the
symplectic shell model of nuclei, we prove the existence of a family of
fermionic Hamiltonians with partial SU(3) symmetry. We outline the construction
process for the PDS eigenstates with good symmetry and give analytic
expressions for the energies of these states and E2 transition strengths
between them. Characteristics of both pure and mixed-symmetry PDS eigenstates
are discussed and the resulting spectra and transition strengths are compared
to those of real nuclei. The PDS concept is shown to be relevant to the
description of prolate, oblate, as well as triaxially deformed nuclei.
Similarities and differences between the fermion case and the previously
established partial SU(3) symmetry in the Interacting Boson Model are
considered.


title: The Hypertriton in Effective Field Theory

abstract:
  Doublet Lambda d scattering and the hypertriton are studied in the framework
of an effective field theory for large scattering lengths. As in the triton
case, consistent renormalization requires a one-parameter three-body force at
leading order whose renormalization group evolution is governed by a limit
cycle. Constraining unknown parameters from symmetry considerations and the
measured binding energy of the hypertriton, we calculate the low-energy phase
shifts for doublet Lambda d scattering. For the low-energy parameters, we find
a_{Lambda d}=(16.8^{+4.4}_{-2.4}) fm and r_{Lambda d}=(2.3 +/- 0.3) fm, where
the errors are due to the uncertainty in the hypertriton binding energy. Since
the hypertriton is extremely shallow, low-energy three-body observables in this
channel are very insensitive to the exact values of the Lambda N low-energy
parameters.


title:
Deformed Boson Scheme including Conventional q-Deformation in
  Time-Dependent Variational Method. III

abstract:
  Basic idea presented in Parts (I) and (II) for the deformed boson scheme is
applied to the case of the su(2,1)-algebra for describing many-body systems
consisting of three kinds of boson operators. A possible form of the coherent
state for the su(2,1)-algebra is generalized and the deformed su(2,1)-algebra
is presented. As an application, the time-evolution of the statistically mixed
state in a certain boson system, which has been already investigated by the
present authors, is reinvestigated.


title: Effective Nucleon-Nucleon Interaction and Fermi Liquid Theory

abstract:
  We present two novel relations between the quasiparticle interaction in
nuclear matter and the unique low momentum nucleon-nucleon interaction in
vacuum. These relations provide two independent constraints on the Fermi liquid
parameters of nuclear matter. Moreover, the new constraints define two
combinations of Fermi liquid parameters, which are invariant under the
renormalization group flow in the particle-hole channels. Using empirical
values for the spin-independent Fermi liquid parameters, we are able to compute
the major spin-dependent ones by imposing the new constraints as well as the
Pauli principle sum rules.


title: An isobar model for eta photo- and electroproduction on the nucleon

abstract:
  Eta photo- and electroproduction on the nucleon is studied using an isobar
model. The model contains Born terms, and contributions from vector meson
exchanges and nucleon resonances. Our results are compared with recent eta
photoproduction data for differential and total cross sections, beam asymmetry,
and target asymmetry, as well as electroproduction data. Besides the dominant
S11(1535) resonance, we show that the second S11 resonance, S11(1650), is also
necessary to be included in order to extract S11(1535) resonance parameters
properly. In addition, the beam asymmetry data allow us to extract very small
(<0.1%) N* --> eta N decay branching ratios of the D13(1520) and F15(1680)
resonances because of the overwhelming s-wave dominance. This model (ETA-MAID)
is implemented as a part of the MAID program.


title:
Centrality Dependence of Thermal Parameters in Heavy-Ion Collisions at
  CERN-SPS

abstract:
  The centrality dependence of thermal parameters, characterizing the hadron
multiplicities, is determined phenomenologically for lead-on-lead collisions at
CERN-SPS for a beam energy of 158 AGeV. The strangeness equilibration factor
shows a clear, approximately linear, increase with increasing centrality, while
the freeze-out temperature and chemical potential remain constant.


title:
The nuclear pions and quark distributions in deep inelastic scattering
  on nuclei

abstract:
  We propose simple Monte Carlo method for calculating parton distribution in
nuclei. The EMC effect is automatically included by means of two parameters,
which characterize the change of nuclear pion field. Good agreement with
experimental data in the broad range of variable x is obtained.


title: A Hydrodynamic Description of Heavy Ion Collisions at the SPS and RHIC

abstract:
  A hydrodynamic + cascade model of relativistic heavy ion collisions is
presented and compared to available hadronic data from the SPS to RHIC. The
model consistently reproduces the radial and elliptic flow data for different
particles, collision energies, and impact parameters. Three ingredients are
essential to the success: (a) a reasonable EOS exhibiting the hard and soft
features of the QCD phase transition, (b) thermal hadronization at the phase
boundary, and (c) subsequent hadronic rescattering. Some features of the RHIC
data are readily explained: (i) the observed elliptic flow and its dependence
on $p_{T}$ and mass, (ii) the anomalous $\bar{p}/\pi^{-}$ ratio for $p_{T}
\approx 2.0$ GeV, (iii) the difference in the slope parameters measured by the
STAR and PHENIX collaborations, and (iv) the respectively strong and weak
impact parameter dependence of the $\bar{p}$ and $\phi$ slope parameters. For
an EOS without the hard and soft features of the QCD phase transition, the
broad consistency with the data is lost.


title:
Singlet-to-triplet ratio in the deuteron breakup reaction $pd\to pnp$ at
  585 MeV

abstract:
  Available experimental data on the exclusive $pd\to pnp$ reaction at 585 MeV
show a narrow peak in the proton-neutron final-state interaction region. It was
supposed previously, on the basis of a phenomenological analysis of the shape
of this peak, that the final spin-singlet $pn$ state provided about one third
of the observed cross section. By comparing the absolute value of the measured
cross section with that of $pd$ elastic scattering using the F\"aldt-Wilkin
extrapolation theorem, it is shown here that the $pd\to pnp$ data can be
explained mainly by the spin-triplet final state with a singlet admixture of a
few percent. The smallness of the singlet contribution is compatible with
existing $pN\to pN\pi$ data and the one-pion exchange mechanism of the $pd\to
pnp$ reaction.


title: Decay Process Sigma to 2 Pions and Chiral Phase Transition

abstract:
  The decay process sigma to 2 pions at high temperature and density and its
relation with chiral phase transition are discussed in the framework of the NJL
model. The decay rate for the process sigma to 2 pions is calculated in the
whole temperature and density region. The contribution of the final state pion
statistics to the decay rate is discussed. The maximum decay rate at different
chemical potential is computed. Finally, we investigate the relation between
the starting point of the decay process and the critical point of the
first-order chiral phase transition.