title:
A general numerical solution of dispersion relations for the nuclear
  optical model

abstract:
  A general numerical solution of the dispersion integral relation between the
real and the imaginary parts of the nuclear optical potential is presented.
Fast convergence is achieved by means of the Gauss-Legendre integration method,
which offers accuracy, easiness of implementation and generality for dispersive
optical model calculations. The use of this numerical integration method in the
optical-model parameter search codes allows for a fast and accurate dispersive
analysis.
  PACS number(s): 11.55.Fv, 24.10.Ht, 02.60.Jh


title: Randomness and Emerging Order in Nuclear Structure

abstract:
  In order to investigate to what extent is the low-lying behavior of even-even
nuclei dependent on particular nucleon-nucleon interactions, we consider
systems of bosons where these interactions are taken as gaussian random numbers
with equal likelyhood of being attractive or repulsive. We find a statistical
dominance of L=0 ground states and other correlations, which we analyze in
terms of a mean field approach.


title:
Covariant axial form factor of the nucleon in a chiral constituent quark
  model

abstract:
  The axial form factor G_A of the nucleon is investigated for the
Goldstone-boson-exchange constituent quark model using the point-form approach
to relativistic quantum mechanics. The results, being covariant, show large
contributions from relativistic boost effects. The predictions are obtained
directly from the quark-model wave functions, without any further input such as
vertex or constituent-quark form factors, and fall remarkably close to the
available experimental data.


title:
Role of dynamical particle-vibration coupling in reconciliation of the
  $d_{3/2}$ puzzle for spherical proton emitters

abstract:
  It has been observed that decay rate for proton emission from $d_{3/2}$
single particle state is systematically quenched compared with the prediction
of a one dimensional potential model although the same model successfully
accounts for measured decay rates from $s_{1/2}$ and $h_{11/2}$ states. We
reconcile this discrepancy by solving coupled-channels equations, taking into
account couplings between the proton motion and vibrational excitations of a
daughter nucleus. We apply the formalism to proton emitting nuclei
$^{160,161}$Re to show that there is a certain range of parameter set of the
excitation energy and the dynamical deformation parameter for the quadrupole
phonon excitation which reproduces simultaneously the experimental decay rates
from the 2$d_{3/2}$, 3$s_{1/2}$ and 1$h_{11/2}$ states in these nuclei.


title:
Order parameter fluctuations and thermodynamic phase transitions in
  finite spin systems and fragmenting nuclei

abstract:
  We show that in small and low density systems described by a lattice gas
model with fixed number of particles the location of a thermodynamic phase
transition can be detected by means of the distribution of the fluctuations
related to an order parameter which is chosen to be the size of the largest
fragment. We show the correlation between the size of the system and the
observed order of the transition. We discuss the implications of this
correlation on the analysis of experimental fragmentation data.


title: Hyperonic crystallization in hadronic matter

abstract:
  Published in Hadrons, Nuclei and Applications, World Scientific, Singapore,
Proc.of the Conference Bologna2000. Structure of the Nucleus at the Dawn of the
Century, G. Bonsignori, M. Bruno, A. Ventura, D. Vretenar Editors, pag. 319.


title:
Evolution of strangeness in equilibrating and expanding quark-gluon
  plasma

abstract:
  We evaluate the strangeness production from equilibrating and transversely
expanding quark gluon plasma which may be created in the wake of relativistic
heavy ion collisions. We consider boost invariant longitudinal and
cylindrically symmetric transverse expansion of a gluon dominated partonic
plasma, which is in local thermal equilibrium. Initial conditions obtained from
the self screened parton cascade model are used. We empirically find that the
final extent of the partonic equilibration rises almost linearly with the
square of the initial energy density. This along with the corresponding
variation with the number of participants may help us distinguish between
various models of parton production.


title: Offshell effects in electromagnetic reactions on the deuteron

abstract:
  Offshell contributions to the electromagnetic nuclear current are evaluated
within a nonrelativistic approach by incorporation one-pion loop contributions
in time-ordered perturbation theory. By construction, the correct experimental
onshell properties of the nucleon current are ensured so that only the genuine
offshell effects appear as model dependent. For a qualitative assessment of
such offshell effects, this model is applied to photodisintegration of the
deuteron for photon energies up to 500 MeV. While at low energies offshell
contributions are small, above 300 MeV they lead to sizeable effects in
observables up to about 30 percent pointing to the necessity of incorporating
such effects if one aims at theoretical predictions of high precision.


title: Kinetic-theory description of isoscalar dipole modes

abstract:
  A semiclassical model, based on a solution of the Vlasov equation for finite
systems with moving-surface, is employed to study the isoscalar dipole modes in
nuclei. It is shown that, by taking into account the surface degree of freedom,
it is possible to obtain an exact treatment of the centre of mass motion. It is
also shown that a method often used to subtract the spurious strength in RPA
calculations does not always give the correct result. An alternative analytical
formula for the intrinsic strength function is derived in a simple
confined-Fermi-gas model. In this model the intrinsic isoscalar dipole strength
displays essentially a two-resonance structure, hence there are two relevant
modes. The interaction between nucleons couples these two modes and changes the
compressibility of the system. The evolution of the strength profile is then
studied as a function of the compressibility of the nuclear fluid. Comparison
with available data favours values of the incompressibility parameter of
nuclear matter smaller than those suggested by the analysis of the monopole
``breathing'' mode.


title: Fluctuations of rare particles as a measure of chemical equilibration

abstract:
  We calculate the time evolution of fluctuations for rare particles such as
e.g. kaons in 1 AGeV or charmonium in 200 AGeV heavy ion collisions. We find
that these fluctuations are a very sensitive probe of the degree of chemical
equilibration reached in these collisions. Furthermore, measuring the second
factorial moment the size of the initial population can be determined.


title: Strangeness equilibration in heavy ion collisions

abstract:
  Using a relativistic transport model for heavy ion collisions at energies
that are below the threshold for kaon and antikaon production in
nucleon-nucleon collisions, we study how their abundances approach the
canonical equilibrium during the collisions. We find that kaons are far from
chemical equilibrium at the initial and high density stage, and they approach
equilibrium only during the expansion stage of the collisions when their
production rate is small and becomes comparable to their annihilation rate. In
contrast, antikaons approach chemical equilibrium much earlier but eventually
fall out of equilibrium again as a result of their large annihilation cross
sections in nuclear matter.


title: Formation of an ordered phase in neutron star matter

abstract:
  In this work, we explore the possible formation of ordered phases in hadronic
matter, related to the presence of hyperons at high densities. We analyze a
microscopic mechanism which can lead to the crystallization of the hyperonic
sector by the confinement of the hyperons on the nodes of a lattice. For this
purpose, we introduce a simplified model of the hadronic plasma, in which the
nuclear interaction between protons, neutrons and hyperons is mediated by meson
fields. We find that, for some reasonable sets of values of the model
parameters, such ordered phases are energetically favoured as density increases
beyond a threshold value.


title: On the pion electroproduction amplitude

abstract:
  We analyze amplitudes for the pion electroproduction on proton derived from
Lagrangians based on the local chiral SU(2) x SU(2) symmetries. We show that
such amplitudes do contain information on the nucleon axial form factor F_A in
both soft and hard pion regimes. This result invalidates recent Haberzettl's
claim that the pion electroproduction at threshold cannot be used to extract
any information regarding F_A.


title: Quantum rotors and their symmetries

abstract:
  A connection between nuclear symmetries other than those of an ellipsoidal
nucleus and the properties of the implied rotational spectra are discussed. The
discussion is focussed on a few examples of exotic shapes predicted recently by
microscopic calculations. Some possible interpretation difficulties related to
experiment are shortly mentioned.


title: Flow analysis from multiparticle azimuthal correlations

abstract:
  We present a new method for analyzing directed and elliptic flow in heavy ion
collisions. Unlike standard methods, it separates the contribution of flow to
azimuthal correlations from contributions due to other effects. The separation
relies on a cumulant expansion of multiparticle azimuthal correlations, and
includes corrections for detector inefficiencies. This new method allows the
measurement of the flow of identified particles in narrow phase-space regions,
and can be used in every regime, from intermediate to ultrarelativistic
energies.


title: Statistical models of nuclear level densities

abstract:
  We present calculations of nuclear level densities that are based upon the
detailed microphysics of the interacting shell model yet are also
computationally tractable. To do this, we combine in a novel fashion several
previously disparate ideas from statistical spectroscopy, namely partitioning
of the model space into subspaces, analytic calculations of moments up to
fourth order directly from the two-body interaction, and Zuker's binomial
distribution. We get excellent agreement with full scale interacting shell
model calculations. We also calculate ``ab initio'' the level densities for
$^{29}$Si and $^{57}$Co and get reasonable agreement with experiment.


title:
Relativistic chiral SU(3) symmetry, large N_c sum rules and meson-baryon
  scattering

abstract:
  The relativistic chiral SU(3) Lagrangian is used to describe kaon-nucleon
scattering imposing constraints from the pion-nucleon sector and the
axial-vector coupling constants of the baryon octet states. We solve the
covariant coupled-channel Bethe-Salpeter equation with the interaction kernel
truncated at chiral order Q^3 where we include only those terms which are
leading in the large N_c limit of QCD. The baryon decuplet states are an
important explicit ingredient in our scheme, because together with the baryon
octet states they form the large N_c baryon ground states of QCD. Part of our
technical developments is a minimal chiral subtraction scheme within
dimensional regularization, which leads to a manifest realization of the
covariant chiral counting rules. All SU(3) symmetry-breaking effects are well
controlled by the combined chiral and large N_c expansion, but still found to
play a crucial role in understanding the empirical data. We achieve an
excellent description of the data set typically up to laboratory momenta of
p_lab about 500 MeV.


title:
Isospin Breaking in Neutron $\beta$-decay and SU(3) Violation in
  Semi-leptonic Hyperon Decays

abstract:
  Present precision measurements of the neutron life time lead to a CKM matrix
element $|V_{ud}|$ which is three standard deviations off the value inferred
from heavy quark decays etc. We investigate the possibility whether
isospin-breaking effects in the neutron-to-proton vector current transition
matrix element $< p|V^+_0|n >=1+\delta g_V$ could eventually close this gap.
For that we calculate in chiral perturbation theory the effect of pion and kaon
loops on the matrix element $< p|V^+_0|n >$ taking into account the mass
differences of the charged and neutral mesons. We find a negligibly small
isospin-breaking effect of $\delta g_V \simeq -4 \cdot 10^{-5}$. The crucial
quantity in the analysis of neutron beta-decay precision measurements is thus
the radiative correction term $\Delta_R$. Furthermore, we calculate in heavy
baryon chiral perturbation theory the SU(3) breaking effects on the vector
transition charges of weak semi-leptonic hyperon decays. We find for these
quantities channel-dependent relative deviations from the SU(3) limit which
range from -10% to $+1%$.


title: Multiphase transport model for heavy ion collisions at RHIC

abstract:
  Using a multiphase transport model (AMPT) with both partonic and hadronic
interactions, we study the multiplicity and transverse momentum distributions
of charged particles such as pions, kaons and protons in central Au+Au
collisions at RHIC energies. Effects due to nuclear shadowing and jet quenching
on these observables are also studied. We further show preliminary results on
the production of multistrange baryons from the strangeness-exchange reactions
during the hadronic stage of heavy ion collisions.


title: Chiral Corrections to Matrix Elements of Twist-2 Operators

abstract:
  We compute the leading non-analytic contributions of the form m_q Log(m_q) to
matrix elements of twist-2 operators in the nucleon and pion using effective
field theory. Previously omitted one-loop contributions that are related to
tree-level matrix elements by chiral symmetry are included.


title: Dissipative Relativistic Fluid Dynamics for Nuclear Collisions

abstract:
  In the context of the M\"uller-Israel-Stewart second-order theory for
dissipative fluids due to Grad, we analyze the effects of thermal conduction
and viscosity in heavy ion collisions. We contrast the results to those of the
first-order theory due to Eckart and to Landau and Lifshitz and to those of
perfect (ideal) fluid due to Euler. We study the energy density and entropy
density evolution of a pion gas produced in the heavy ion collisions. The
truncated version of the second-order theory is used to find the dissipative
quantities.


title:
Anomalous rotational-alignment in N=Z nuclei and residual neutron-proton
  interaction

abstract:
  Recent experiments have demonstrated that the rotational-alignment for the
$N=Z$ nuclei in the mass-80 region is considerably delayed as compared to the
neighboring $N \ne Z$ nuclei. We investigate whether this observation can be
understood by a known component of nuclear residual interactions. It is shown
that the quadrupole-pairing interaction, which explains many of the delays
known in rare-earth nuclei, does not produce the substantial delay observed for
these $N=Z$ nuclei. However, the residual neutron-proton interaction which is
conjectured to be relevant for $N=Z$ nuclei is shown to be quite important in
explaining the new experimental data.


title: The S Wave Pion Deuteron Scattering Length in Effective Field Theory

abstract:
  The S wave pion deuteron scattering length is presented at NLO in the
Effective Field Theory formulation of the two nucleon system with perturbative
pions. At this order, this observable is determined by the iso-scalar S wave
pion nucleon scattering length a^+, by pion re-scattering contributions inside
the deuteron and by two nucleon two pion contact interactions that involve two
unknown parameters which renormalise the appearing divergences. By choosing
their values accordingly and in agreement with their natural sizes predicted by
the power counting, we are able to accommodate the available experimental data.
However, a^+ cannot be determined from pion deuteron scattering directly. An
ongoing experiment at PSI aiming to reduce the error bars by an order of
magnitude will make it possible to pin down the size of these counter terms
more accurately. We compare our findings to an approach in which pions are
treated non-perturbatively.


title:
Pairing correlations. Part 1: description of odd nuclei in mean-field
  theories

abstract:
  In order to extract informations on pairing correlations in nuclei from
experimental mass differences, the different contributions to odd-even mass
differences are investigated within the Skyrme HFB method. In this first paper,
the description of odd nuclei within HFB is discussed since it is the key point
for the understanding of the above mentioned contributions. To go from an even
nucleus to an odd one, the advantage of a two steps process is demonstrated and
its physical content is discussed. New results concerning time-reversal
symmetry breaking in odd-nuclei are also reported.
  PACS: 21.10Dr; 21.10.Hw; 21.30.-x.
  Keywords: Mean-field theories; Pairing correlations; odd nuclei;


title:
Pairing correlations. Part 2: Microscopic analysis of odd-even mass
  staggering in nuclei

abstract:
  The odd-even mass staggering in nuclei is analyzed in the context of
self-consistent mean-field calculations, for spherical as well as for deformed
nuclei. For these nuclei, the respective merits of the energy differences
$\Delta^{(3)}$ and $\Delta^{(5)}$ to extract both the pairing gap and the
time-reversal symmetry breaking effect at the same time are extensively
discussed. The usual mass formula $\Delta^{(3)}$, is shown to contain
additional mean-field contributions when realistic pairing is used in the
calculation. A simple tool is proposed in order to remove time-reversal
symmetry breaking effects from $\Delta^{(5)}$. Extended comparisons with the
odd-even mass staggering obtained in the zero pairing limit (schematic model
and self-consistent calculations) show the non-perturbative contribution of
pairing correlations on this observable.
  PACS: 21.10Dr; 21.10.Hw; 21.30.-x.
  Keywords: Mean-field theories; Pairing correlations; Odd-even mass
staggering;


title:
Chiral Effective Field Theories with explicit Spin 3/2 Degrees of
  Freedom---A Status Report

abstract:
  Recent developments in calculations of low energy nucleon properties
utilizing effective chiral field theories with explicit spin 3/2 matter fields
are presented. In particular, the role of Delta resonances in microscopic
calculations of the anomalous magnetic moments of the Nucleon is discussed and
a comparison to lattice data is performed. Furthermore, the impact of Deltas on
the isovector Pauli form factor of the Nucleon and the problems one faces in
calculations of the isovector Nucleon-Delta transition form factors are
addressed.


title:
Neutron structure function and inclusive DIS from H-3 and He-3 at large
  Bjorken-x

abstract:
  A detailed study of inclusive deep inelastic scattering (DIS) from mirror A =
3 nuclei at large values of the Bjorken variable x is presented. The main
purpose is to estimate the theoretical uncertainties on the extraction of the
neutron DIS structure function from such nuclear measurements. On one hand,
within models in which no modification of the bound nucleon structure functions
is taken into account, we have investigated the possible uncertainties arising
from: i) charge symmetry breaking terms in the nucleon-nucleon interaction, ii)
finite Q**2 effects neglected in the Bjorken limit, iii) the role of different
prescriptions for the nucleon Spectral Function normalization providing baryon
number conservation, and iv) the differences between the virtual nucleon and
light cone formalisms. Although these effects have been not yet considered in
existing analyses, our conclusion is that all these effects cancel at the level
of ~ 1% for x < 0.75 in overall agreement with previous findings. On the other
hand we have considered several models in which the modification of the bound
nucleon structure functions is accounted for to describe the EMC effect in DIS
scattering from nuclei. It turns out that within these models the cancellation
of nuclear effects is expected to occur only at a level of ~ 3%, leading to an
accuracy of ~ 12 % in the extraction of the neutron to proton structure
function ratio at x ~ 0.7 -0.8$. Another consequence of considering a broad
range of models of the EMC effect is that the previously suggested iteration
procedure does not improve the accuracy of the extraction of the neutron to
proton structure function ratio.


title: Monte Carlo Models: Quo Vadimus?

abstract:
  Coherence, multiple scattering and the interplay between soft and hard
processes are discussed. These physics phenomena are essential for
understanding the nuclear dependences of rapidity density and $p_T$ spectra in
high-energy heavy-ion collisions. The RHIC data have shown the onset of hard
processes and indications of high $p_T$ spectra suppression due to parton
energy loss. Within the pQCD parton model, the combination of azimuthal
anisotropy ($v_2$) and hadron spectra suppression at large $p_T$ can help one
to determine the initial gluon density in heavy-ion collisions at RHIC.


title: In-medium broadening of nucleon resonances

abstract:
  We analyze the effects of an in-medium broadening of nucleon resonances on
the exclusive photoproduction of mesons on nuclei as well as on the total
photoabsorption cross sections in a transport calculation. We show that the
resonance widths observed in semi-inclusive photoproduction on nuclei are
insensitive to an in-medium broadening of nucleon resonances. This is due to a
simple effect: the sizeable width of the nuclear surface and Fermi motion.


title: Instantons As Unitary Spin Maker

abstract:
  We investigate the relevance of the instanton-induced determinantal 't Hooft
interaction to the eta-nucleon coupling within the framework of a three-flavor
linear sigma model in the OZI-rule-respecting basis. Instantons, in combination
with the spontaneous breaking of chiral symmetry, are shown to provide the
major mechanism for the ideal mixing between pseudoscalar strange and
non-strange quarkonia. As long as 't Hooft's interaction captures most of the
basic features of the axial QCD gluon anomaly, we identify the anomaly as the
main culprit for the appearance of octet flavor symmetry in the anomalous
sectors of the pseudoscalar (and axial vector) mesons. Within this context,
unitary spin is shown to be an accidental symmetry due to anomalous gluon
dynamics rather than a fundamental symmetry in its own right. Though we find
the eta-nucleon coupling constant to obey a Goldberger-Treiman like relation,
the latter does not take its origin from a pole dominance of the induced
pseudoscalar form factor of the octet axial current, but from a subtle
flavor-mixing mechanism that is traced back to instanton dynamics. The model
presented allows for possible generalizations to non-ideal mixing angles and
different values of the meson decay constants in the strange and non-strange
sectors, respectively. Finally, we discuss the issue as to what extent the eta
meson may be considered as a Goldstone boson under the constraints of the
anomaly-produced unitary spin.


title: Spin structure of the Delta(1232) and inelastic Compton scattering

abstract:
  Radiative transitions gamma + Delta(1232) -> N^* are discussed in the
nonrelativistic quark model with spin-orbit corrections for the 70-plet L^P=1^-
nucleon resonances N^*. The reaction gamma + N -> gamma + Delta is considered
as a tool to measure some of these transitions. A particular sensitivity to
photoexcitations of S_{11}(1535), D_{13}(1700), and D_{15}(1675) is predicted.


title: Chiral Dynamics and Nuclear Matter

abstract:
  We calculate the equation of state of isospin-symmetric nuclear matter in the
three-loop approximation of chiral perturbation theory. The contributions to
the energy per particle $\bar E(k_f)$ from one- and two-pion exchange diagrams
are ordered in powers of the Fermi momentum $k_f$ (modulo functions of $k_f
/m_\pi$). It is demonstrated that, already at order ${\cal O}(k_f^4)$, two-pion
exchange produces realistic nuclear binding. The underlying saturation
mechanism is surprisingly simple (in the chiral limit), namely the combination
of an attractive $k_f^3$-term and a repulsive $k_f^4$-term. The empirical
saturation point and the nuclear compressibility $K\simeq 250 $MeV are well
reproduced at order ${\cal O}(k_f^5)$ with a momentum cut-off of $\Lambda
\simeq 0.65$ GeV which parametrizes short-range dynamics. No further
short-distance terms are required in our calculation of nuclear matter. In the
same framework we calculate the density-dependent asymmetry energy and find
$A_0\simeq 34 $MeV at the saturation point, in good agreement with the
empirical value. The pure neutron matter equation of state is also in fair
qualitative agreement with sophisticated many-body calculations and a
resummation result of effective field theory, but only for low neutron
densities $\rho_n <0.25 $fm$^{-3}$.


title: Charmonium - Pion Cross Section from QCD Sum Rules

abstract:
  The $J/\psi \pi\to \bar{D} D^*, \bar{D} D$, ${\bar D}^* D^*$ and ${\bar D}
D^*$ cross sections as a function of $\sqrt{s}$ are evaluated in a QCD sum rule
calculation. We study the Borel sum rule for the four point function involving
pseudoscalar and vector meson currents, up to dimension four in the operator
product expansion. We find that our results are smaller than the $J/\psi \pi\to
{charmed mesons}$ cross sections obtained with models based on meson exchange,
but are close to those obtained with quark exchange models.


title:
Short-range correlations in semi-exclusive electron scattering
  experiments

abstract:
  One-nucleon emission electron scattering experiments are studied with a model
that considers short--range correlations up to the first order in the number of
correlation lines. The proper normalization of the many-body wave functions
requires the evaluation of two- and three-point diagrams, the last ones usually
neglected in the literature. When all these diagrams are included the effects
of the short-range correlations are rather small. The results of our
calculations are compared with experimental data taken on $^{16}$O.


title: First-forbidden mirror beta-decays in A=17 mass region

abstract:
  The first-forbidden beta-decay of 17Ne into the 'halo' state J=1/2+ of 17F
presents one of the largest measured asymmetries for mirror beta-decay feeding
bound final states. This asymmetry is studied in the framework of the Shell
Model Embedded in the Continuum (SMEC). The spatial extent of single particle
orbits is constrained by the proton capture cross-section 16O(p,gamma)17F
calculated in SMEC . This allows to estimate the mirror symmetry breaking in
17F/17O and 17Ne/17N nuclei.


title: On the muon capture in 28^Si and extraction of g_P

abstract:
  Comparison of the new data for the negative muon capture in 28^Si with the
recent shell model calculations using a full 1s-0d model space and the USD
empirical effective interaction and the one-nucleon weak current provides the
induced pseudoscalar g_P substantially smaller than the value predicted by PCAC
and pion-pole dominance. We find that adding the effect from the one-pion
exchange axial charge density and using the same scheme of calculations does
not change situation to the value of g_P.


title: Toward a Spin- and Parity-Independent Nucleon-Nucleon Potential

abstract:
  A supersymmetric inversion method is applied to the singlet $^1S_0$ and
$^1P_1$ neutron-proton elastic phase shifts. The resulting central potential
has a one-pion-exchange (OPE) long-range behavior and a parity-independent
short-range part; it fits inverted data well. Adding a regularized OPE tensor
term also allows the reproduction of the triplet $^3P_0$, $^3P_1$ and $^3S_1$
phase shifts as well as of the deuteron binding energy. The potential is thus
also spin-independent (except for the OPE part) and contains no spin-orbit
term. These important simplifications of the neutron-proton interaction are
shown to be possible only if the potential possesses Pauli forbidden bound
states, as proposed in the Moscow nucleon-nucleon model.


title:
Relativistic Generalization of the Post-Prior Equivalence for Reaction
  of Composite Particles

abstract:
  In the non-relativistic description of the reaction of composite particles,
the reaction matrix is independent of the choice of post or prior forms for the
interaction. We generalize this post-prior equivalence to the relativistic
reaction of composite particles by using Dirac's constraint dynamics to
describe the bound states and the reaction process.


title: New Magic Numbers and New Islands of Stability in Drip-Line Regions

abstract:
  The systematics of the local energies and the two-neutron separation energies
obtained in the mass predictions of infinite nuclear matter model of atomic
nuclei show strong evidence of new neutron magic numbers 100,152,164, new
proton magic number 78 and new islands of stability around N=100, Z $\simeq$
62; N=152,Z=78; and N=164,Z$\simeq$90 in the drip line regions of nuclear
chart,where the usual magic numbers are found to be no more valid.


title: Spin-vibrational 1+ states in 140Ce

abstract:
  The properties of collective I^$\Pi$=1+ states in double even semimagic
nucleus 140Ce are investigated in random phase approximation(RPA). The
calculation of the B(M1) strength, elastic gamma-scattering cross section
$\sigma_(gamma)(\omega)$ and gamma-decay width $\Sigma_(gamma)(\omega_i)$ show
that in 140Ce the isovector spin-spin interactions concenrate the main strength
of M1 transition at energy 7.89 MeV where the isovector spin-flip magnetic
resonance may appear. The predisctions are consistent with the observed M1
strength in 140Ce which is seen to be concentrated within a range of about 0.8
MeV centered at an excitation of 7.95 MeV.


abstract:
  Retardation effects from quark confinement on low-energy nucleon dynamics are
investigated within the generalized quantum dynamics (GQD). It is shown that
the GQD provides an extension of Hamiltonian dynamics which can describe the
evolution of systems of hadrons whose interaction is nonlocal in time due to
quark-gluon retardation effects. This is illustrated by the example of the
dynamics of nucleons with internal structure described by a constitute quark
model. It is shown that quark-gluon retardation effects result in an anomalous
off-shell behavior of the two-nucleon amplitudes, and in a lack of continuity
of the evolution operator describing nucleon dynamics; for this reason
low-energy nucleon dynamics is not governed by the Schr{\"o}dinger equation.
This is shown to have substantial effects on the dynamics of many nucleon
systems. It is also shown that the GQD allows one to take into account
retardation effects from quark confinement in describing the short-range part
of the $NN$ interaction.
  PACS number(s): 24.85.+p, 13.75.Cs, 21.30.-x


title:
Self consistent propagation of hyperons and antikaons in nuclear matter
  based on relativistic chiral SU(3) dynamics

abstract:
  We evaluate the antikaon spectral density in isospin symmetric nuclear
matter. The in-medium antikaon-nucleon scattering process and the antikaon
propagation is treated in a self consistent and relativistic manner where a
maximally scheme-independent formulation is derived by performing a partial
density resummation in terms of the free-space antikaon-nucleon scattering
amplitudes. The latter amplitudes are taken from a covariant and chiral
coupled-channel SU(3) approach which includes s-, p- and d-waves
systematically. Particular care is taken on the proper evaluation of the
in-medium mixing of the partial waves. Our analysis establishes a rich
structure of the antikaon spectral function with considerable strength at small
energies. At nuclear saturation density we predict attractive mass shifts for
the $\Lambda(1405)$, $\Sigma (1385)$ and $\Lambda(1520)$ of about 60 MeV, 60
MeV and 100 MeV respectively. The hyperon states are found to exhibit at the
same time an increased decay width of about 120 MeV for the s-wave
$\Lambda(1405)$, 70 MeV for the p-wave $\Sigma (1385)$ and 90 MeV for the
d-wave $\Lambda(1520)$ resonance.


title: Covariant meson-baryon scattering with chiral and large N_c constraints

abstract:
  We give a review of recent progress on the application of the relativistic
chiral SU(3) Lagrangian to meson-baryon scattering. It is shown that a combined
chiral and 1/N_c expansion of the Bethe-Salpeter interaction kernel leads to a
good description of the kaon-nucleon, antikaon-nucleon and pion-nucleon
scattering data typically up to laboratory momenta of p_lab about 500 MeV. We
solve the covariant coupled channel Bethe-Salpeter equation with the
interaction kernel truncated to chiral order Q^3 where we include only those
terms which are leading in the large N_c limit of QCD.


title: Antibaryon production in hot and dense nuclear matter

abstract:
  The production of antibaryons is calculated in a microscopic transport
approach employing multiple meson fusion reactions according to detailed
balance relations with respect to baryon-antibaryon annihilation. It is found
that the abundancies of antiprotons as observed from peripheral to central
collisions of $Pb + Pb$ at the SPS and $Au + Au$ at the AGS can approximately
be described on the basis of multiple interactions of 'formed' hadronic states
which drive the system to chemical equilibrium by flavor exchange or quark
rearrangement reactions.


title:
A Mathematica Program Using Isotropic Harmonic Oscillator Eigenstates to
  Model Alpha-Particle Tunneling Half Life Variability

abstract:
  We have developed a Mathematica program which uses three-dimensional,
isotropic harmonic oscillator wavefunctions for the solutions interior to the
nucleus, and Coulomb wavefunctions for the exterior. The algorithm enables us
to calculate the half life for alpha decay for alpha decay for varying depths
of the nuclear potential well.


title: Test of Nuclear Wave Functions for Pseudospin Symmetry

abstract:
  Using the fact that pseudospin is an approximate symmetry of the Dirac
Hamiltonian with realistic scalar and vector mean fields, we derive the wave
functions of the pseudospin partners of eigenstates of a realistic Dirac
Hamiltonian and compare these wave functions with the wave functions of the
Dirac eigenstates.


title: Range Corrections to Doublet S-Wave Neutron-Deuteron Scattering

abstract:
  We calculate the range corrections to S-wave neutron-deuteron scattering in
the doublet channel (S=1/2) to first order in r/a where a is the scattering
length and r the effective range. Ultraviolet divergences appearing at this
order can be absorbed into a redefinition of the leading order three-body
force. The corrections to the elastic scattering amplitude below the deuteron
breakup threshold are computed. Inclusion of the range corrections gives good
agreement with measured scattering data and potential model calculations.


title: Symmetries and staggering effects in nuclear rotational spectra

abstract:
  We study the fine structure of nuclear rotational spectra on the basis of
both dynamical and discrete symmetry approaches. In this framework we show that
the odd--even (Delta I = 1) staggering effects observed in various rotational
bands carry detailed information about the collective band-mixing interactions
and the collective shape properties of heavy nuclei.


title: Generalized Polarizabilities in a Constituent Quark Model

abstract:
  We discuss low-energy virtual Compton scattering off the proton within the
framework of a nonrelativistic constituent quark model. A simple interpretation
of the spin-averaged generalized polarizabilities is given in terms of the
induced electric polarization (and magnetization). Explicit predictions for the
generalized polarizabilities obtained from a multipole expansion are presented
for the Isgur-Karl model and are compared with results of various models.


title:
Nucleon-Nucleon and Nucleon-Nucleus Optical Models for Energies to 3 GeV
  and the Question of NN Hadronization

abstract:
  Within the key issues of hadronic physics one of the interesting issues in
nuclear physics is whether there is a transition region between meson-nucleon
and quark-gluon degrees of freedom in the NN interaction. This question is
relevant for pairs of free nucleons as well as for nucleon pairs immersed in
nuclear matter. From NN phase shifts we deduce a dibaryonic scale of 1 GeV for
the soft core NN potential strengths at nucleon separation r equal 0.25 to 0.5
fm. A short range intermediate transition, with fusion and fission of the two
scattered nucleons into a dibaryon with prevailing quark-gluon dynamics, is
conjectured from NN optical models for T-lab greater 1.5 GeV. From efforts and
progress of nucleon-nucleus scattering analysis in the GeV region some results
are presented. This is our first step for an in-medium search for transitions
from the meson-nucleon into the quark-gluon sector using NA optical models.


title:
Scaling of space and timelike response of confined relativistic
  particles

abstract:
  The response of a relativistic particle bound in a linear confining well is
calculated as a function of the momentum and energy transfer, q, \nu. At large
values of |q| the response exhibits scaling in the variable y=\nu-|q|, which is
proportional to the Nachtmann variable, \xi. The approach to scaling is studied
at smaller values of |q|. Scaling occurs at \nu~|q| at relatively small |q|,
and its validity extends over the entire \xi range as |q| increases; this
behavior is observed in electron-proton scattering. About 10% of the response
at large |q| is in the timelike region where \nu>|q|, and it is necessary to
include it to fulfill the particle number sum rule. The Gross-Llewellyn Smith
and Gottfried sum rules are discussed in the context of these results.


title:
Delta I = 1 staggering in octupole bands of light actinides: "Beat"
  patterns

abstract:
  The Delta I = 1 staggering (odd--even staggering) in octupole bands of light
actinides is found to exhibit a ``beat'' behaviour as a function of the angular
momentum I, forcing us to revise the traditional belief that this staggering
decreases gradually to zero and then remains at this zero value. Various
algebraic models (spf-Interacting Boson Model, spdf-IBM, Vector Boson Model,
Nuclear Vibron Model) are shown to predict in their su(3) limits constant
staggering for this case, being thus unable to describe the ``beat'' behaviour.
An explanation of the ``beat'' behaviour is given in terms of two Dunham
expansions (expansions in terms of powers of I(I+1)) with slightly different
sets of coefficients for the ground state band and the negative parity band,
the difference in the values of the coefficients being attributed to Coriolis
couplings to other negative parity bands. Similar ``beat'' patterns have
already been seen in rotational bands of some diatomic molecules, like AgH.


title:
Description of collective magnetic states within a spherical single
  particle basis

abstract:
  A many body Hamiltonian comprising pairing, quadrupole-quadrupole and
spin-spin interaction is treated within a projected spherical basis with the
aim of describing the detailed structure of the magnetic states of orbital and
spin-flip nature in $^{144, 148-154}$Sm. The mean field for the single particle
motion takes care of the volume conservation of a phenomenological core which
results in having a complex dependence on deformation for single particle
energies. Several experimental features like the total orbital and total spin
strengths, the shape of the orbital strength distribution, the hump structure
of the spin strength distribution, the quadratic dependence of the orbital
strength on nuclear deformation, the saturation effect of the orbital strength
with respect to the Casten's factor P are very well described within a
quasiparticle random phase approximation formalism. Comparison of present
results with those obtained in some previous treatments are also given.


title: Coulomb effects in nucleon-deuteron polarization-transfer coefficients

abstract:
  Coulomb effects in the neutron-deuteron and proton-deuteron
polarization-transfer coefficients $K_y^{y'}$, $K_z^{x'}$, $K_y^{x'x'-y'y'}$
and $K_y^{z'z'}$ are studied at energies above the deuteron breakup threshold.
Theoretical predictions for these observables are evaluated in the framework of
the Kohn Variational Principle using correlated basis functions to expand the
three-nucleon scattering wave function. The two-nucleon Argonne $v_{18}$ and
the three-nucleon Urbana IX potentials are considered. In the proton-deuteron
case, the Coulomb interaction between the two protons is included explicitly
and the results are compared to the experimental data available at
$E_{lab}=10,19,22.7$ MeV. In the neutron-deuteron case, a comparison to a
recent measurement of $K_y^{y'}$ by Hempen {\sl et al.} at $E_{lab}=19$ MeV
evidences a contribution of the calculated Coulomb effects opposite to those
extracted from the experiment.


title: Rotations of nuclei with reflection asymmetry correlations

abstract:
  We propose a collective Hamiltonian which incorporates interactions capable
to generate rotations in nuclei with simultaneous presence of octupole and
quadrupole deformations. It is demonstrated that the model formalism could be
applied to reproduce the staggering effects observed in nuclear octupole bands.
On this basis we propose that the interactions involved would provide a
relevant handle in the study of collective phenomena in nuclei and other
quantum mechanical systems with reflection asymmetry correlations.


title: Hamiltonian hierarchy and the Hulthen potential

abstract:
  We deal with the Hamiltonian hierarchy problem of the Hulth\'{e}n potential
within the frame of the supersymmetric quantum mechanics and find that the
associated superymmetric partner potentials simulate the effect of the
centrifugal barrier. Incorporating the supersymmetric solutions and using the
first-order perturbation theory we obtain an expression for the energy levels
of theHulth\'{e}n potential which gives satisfactory values for the non-zero
angular momentum states.


title:
Deuteron Electromagnetic Properties with a Poincar\'e-Covariant Current
  Operator within Front-Form Hamiltonian Dynamics

abstract:
  Deuteron elastic and deep inelastic electromagnetic properties have been
studied within the front-form Hamiltonian dynamics, using a
Poincar\'e-covariant current operator. The deuteron elastic form factors are
strongly sensitive to different realistic $N-N$ interactions, while the
relevance of different nucleon form factor models is huge for $A(Q^2)$, weak
for $B(Q^2)$ and negligible for the tensor polarization. The possibility to
gain information on the neutron charge form factor from an analysis of $A(Q^2)$
has been investigated. The extraction of the neutron structure functions from
the deuteron deep inelastic structure functions at high $x$ is largely affected
by the use of our Poincar\'e-covariant relativistic approach instead of the
usual impulse approximation within an instant-form approach.


title:
Study of polarization observables in double pion photoproduction on the
  proton

abstract:
  Using a model for two pion photoproduction on the proton previously tested in
total cross sections and invariant mass distributions, we evaluate here
polarization observables on which recent experiments are providing new
information. We evaluate cross sections for spin 1/2 and 3/2, which are
measured at Mainz and play an important role in tests of the GHD sum rule.
  We also evaluate the proton polarization asymmetry $\Sigma$ which is
currently under investigation at GRAAL in Grenoble.


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

abstract:
  An isobar model containing Born terms, vector meson exchange and nucleon
resonances is used to analyze recent eta photoproduction data for cross section
and beam asymmetry, as well as JLab electroproduction data. Good overall
description is achieved up to Q^2 = 4.0 (GeV/c)^2. 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 D13(1520) and F15(1680)
resonances because of the overwhelming s-wave dominance. The model is
implemented as a part of the MAID program.


title: Resonance saturation for four-nucleon operators

abstract:
  In the modern description of nuclear forces based on chiral effective field
theory, four-nucleon operators with unknown coupling constants appear. These
couplings can be fixed by a fit to the low partial waves of neutron-proton
scattering. We show that the so determined numerical values can be understood
on the basis of phenomenological one-boson-exchange models. We also extract
these values from various modern high accuracy nucleon-nucleon potentials and
demonstrate their consistency and remarkable agreement with the values in the
chiral effective field theory approach. This paves the way for estimating the
low-energy constants of operators with more nucleon fields and/or external
probes.


title:
"Beat" patterns for the odd-even staggering in octupole bands from a
  quadrupole-octupole Hamiltonian

abstract:
  We propose a collective Hamiltonian which incorporates the standard
quadrupole terms, octupole terms classified according to the irreducible
representations of the octahedron group, a quadrupole-octupole interaction, as
well as a term for the bandhead energy linear in K (the projection of angular
momentum on the body-fixed z-axis). The energy is subsequently minimized with
respect to K for each given value of the angular momentum I, resulting in K
values increasing with I within each band, even in the case in which K is
restricted to a set of microscopically plausible values. We demonstrate that
this Hamiltonian is able to reproduce a variety of ``beat'' patterns observed
recently for the odd-even staggering in octupole bands of light actinides.


title: Thermal analysis of particle ratios and p_T spectra at RHIC

abstract:
  The thermal model of particle production is used to analyze the particle
ratios and the p_T spectra measured recently at RHIC. Our fit of the particle
ratios yields the temperature at the chemical freeze-out T_chem = 165 +- 7 MeV
with the corresponding baryon chemical potential mu^B_chem = 41 +- 5 MeV. The
quality of the fit shows that the model works well for RHIC. The p_T spectra
are evaluated in an approach which takes into account the modifications of the
initial thermal distributions by the secondary decays of resonances. All two-
and three-body decays are included. This leads to an effective ``cooling'' of
the spectra in the data region by about 35-40 MeV. We find that the pion
spectrum is characterized by the inverse slope which agrees well with the value
inferred from the RHIC data.


title: Baryon Fluctuations and the QCD Phase Transition

abstract:
  The dynamic separation into phases of high and low baryon density in a heavy
ion collision can enhance fluctuations of the net rapidity density of baryons
compared to model expectations. We demonstrate that event-by-event proton and
antiproton measurements can be used to observe this phenomenon. We then perform
real-time lattice simulations to show how these fluctuations arise and how they
can survive through freeze out.


title: The Character of Goldstone Bosons

abstract:
  A succinct review of the QCD gap equation and dynamical chiral symmetry
breaking; their connection with Bethe-Salpeter equations and resolving the
dichotomous nature of the pion; the calculation of the pion's valence-quark
distribution; and first results for the pi-exchange contribution to the gamma N
-> omega N cross-section, which is important in the search for missing nucleon
resonances.


title: Formation Of Quark Matter In Neutron Stars

abstract:
  At very large densities and/or temperatures a quark-hadron phase transition
is expected to take place. Simulations of QCD on lattice at zero baryon density
indicate that the transition occurs at $T_c \sim 150-170$ MeV. The calculations
indicate that transition is likely to be second order or a cross over
phenomenon. Although the lattice simulations have not given any indication on
when the transition occurs at nonzero baryon density, the transition is
expected to occur around the densities of few times nuclear matter density.
Also, there is a strong reason to believe that the quark matter formed after
the phase transition is in colour superconducting phase. The matter densities
in the interior of neutron stars are expected to be several times the nuclear
matter density and therefore the neutron star cores may possibly consist of
quark matter. One then expects that this quark matter is formed during the
collapse of supernova. Starting with the assumption that the quark matter, when
formed consists of predominantly u and d quarks, we consider the evolution of
strange quarks by weak interactions in the present work. The reaction rates and
time required to reach the chemical equilibrium are computed here. Our
calculations show that the chemical equilibrium is reached in about $10^{-7}$
seconds. Further more during and immediately after the equilibration process
enormous amount of energy is released and copious numbers of neutrinos are
produced. We show that for reasonable models of nuclear equations of state the
amount of energy released could be as high as $10^{53}$ ergs and as many as
$10^{58}$ neutrinos may be emitted during the quark matter formation.


title:
GCM Analysis of the collective properties of lead isotopes with exact
  projection on particle numbers

abstract:
  We present a microscopic analysis of the collective behaviour of the lead
isotopes in the vicinity of Pb208. In this study, we rely on a coherent
approach based on the Generator Coordinate Method including exact projection on
N and Z numbers within a collective space generated by means of the constrained
Hartree-Fock BCS method. With the same Hamiltonian used in HF+BCS calculations,
we have performed a comprehensive study including monopole, quadrupole and
octupole excitations as well as pairing vibrations. We find that, for the
considered nuclei, the collective modes which modify the most the conclusions
drawn from the mean-field theory are the octupole and pairing vibrations.


title: Nuclei, Superheavy Nuclei and Hypermatter in a chiral SU(3)-Modell

abstract:
  A model based on chiral SU(3)-symmetry in nonlinear realisation is used for
the investigation of nuclei, superheavy nuclei, hypernuclei and multistrange
nuclear objects (so called MEMOs). The model works very well in the case of
nuclei and hypernuclei with one Lambda-particle and rules out MEMOs. Basic
observables which are known for nuclei and hypernuclei are reproduced
satisfactorily. The model predicts Z=120 and N=172, 184 and 198 as the next
shell closures in the region of superheavy nuclei. The calculations have been
performed in self-consistent relativistic mean field approximation assuming
spherical symmetry. The parameters were adapted to known nuclei.


title:
Extracting the spectral function of He-4 from a relativistic plane-wave
  treatment

abstract:
  The spectral function of He-4 is extracted from a plane-wave approximation to
the (e,e'p) reaction using a fully relativistic formalism. We take advantage of
both an algebraic ``trick'' and a general relativistic formalism for quasifree
processes developed earlier to arrive at transparent, analytical expressions
for all quasifree (e,e'p) observables. An observable is identified for the
clean and model-independent extraction of the spectral function. Our simple
relativistic plane-wave calculations provide baseline predictions for the
recently measured, but not yet fully analyzed, momentum distribution of He-4 by
the A1-collaboration from Mainz. Yet in spite of its simplicity, our approach
predicts momentum distributions for He-4 that rival some of the best
nonrelativistic calculations to date. Finally, we highlight some of the
challenges and opportunities that remain, both theoretically and
experimentally, in the extraction of quasifree observables.


title:
Ambiguities in the implementation of the impulse approximation for the
  response of many-fermion systems

abstract:
  Within the impulse approximation the response of a many body system at large
momentum tranfer can be written in a simple and transparent form, allowing to
directly relate the inclusive scattering cross section to the properties of the
target ground state. Although the physics assumptions underlying impulse
approximation are well defined, their implementation involves ambiguities that
may cause significant differences in the calculated responses. We show that,
while minimal use of the impulse approximation assumptions naturally leads to
write the response in terms of the target spectral function, the widely used
alternative definition in terms of the momentum distribution involves a more
extended use of the same assumtpions. The difference between the responses
resulting from the two procedures is illustrated by two examples.


title: Instabilities in a Mean-field dynamics of Asymmetric Nuclear Matter

abstract:
  We discuss the features of instabilities in asymmetric nuclear matter, in
particular the relation between the nature of fluctuations, the types of
instabilities and the properties of the interaction. We show a chemical
instability appears as an instability against isoscalar-like fluctuations. Then
starting from phenomenological hadronic field theory (QHD), including exchange
terms, we discuss the symmetry energy and the relation to the dynamical
response inside the spinodal region.


title: Fragile Signs of Criticality in the Nuclear Multifragmentation

abstract:
  Deviations from an idealized equilibrium phase transition picture in nuclear
multifragmentation is studied in terms of the entropic index. We investigate
different heat-capacity features in the canonical quantum statistical model of
nuclear multifragmentation generalized in the framework of Tsallis nonextensive
thermostatistics. We find that the negative branch of heat capacity observed in
quasi-peripheral Au+Au collisions is caused primarily by the non-generic
nonextensivity effects.


title:
Comparison of Canonical and Grand Canonical Models for selected
  multifragmentation data

abstract:
  Calculations for a set of nuclear multifragmentation data are made using a
Canonical and a Grand Canonical Model. The physics assumptions are identical
but the Canonical Model has an exact number of particles, whereas, the Grand
Canonical Model has a varying number of particles, hence, is less exact.
Interesting differences are found.


title: Spectroscopy with random and displaced random ensembles

abstract:
  Due to the time reversal invariance of the angular momentum operator J^2, the
average energies and variances at fixed J for random two-body Hamiltonians
exhibit odd-even-J staggering, that may be especially strong for J=0. It is
shown that upon ensemble averaging over random runs, this behaviour is
reflected in the yrast states. Displaced (attractive) random ensembles lead to
rotational spectra with strongly enhanced BE2 transitions for a certain class
of model spaces. It is explained how to generalize these results to other forms
of collectivity.


title:
"Aspin" bubbles: a mechanical theory for the unification of the forces
  of Nature

abstract:
  This paper describes a mechanical theory for the unification of the basic
forces of Nature with only one wave-particle interaction. The theory is based
on the hypothesis that the ultimate components of matter are just two kind of
pulsing particles. The interaction between these particles submerged in a
fluid-like medium (aether) reproduces all the forces in Nature: electric,
magnetic, nuclear, gravity, atomic, van der Waals, Casimir, etc. The theory
also depicts the internal structure of the atom and of the fundamental
particles that are currently known. Thus, a new concept of physics, capable of
tackling entirely new problems, is introduced.


title: Isospin dependence of nuclear matter symmetry energy coefficients

abstract:
  Generalized symmetry energy coefficients of asymmetric nuclear matter are
obtained as screening functions. The dependence of the isospin symmetry energy
coefficient on the neutron proton (n-p) asymmetry may be determined unless by a
constant (exponent) $Z$ which depend on microscopic properties. The dependence
of the generalized symmetry energy coefficients with Skyrme forces on the n-p
asymmetry and on the density, only from .5 up to 1.5 $\rho_0$, are investigated
in the isospin and scalar channels. The use of Skyrme-type effective forces
allows us to obtain analytical expressions for these parameters as well as
their dependences on the neutron-proton (n-p) asymmetry, density and even
temperature. Whereas the density dependence of these coefficients obtained with
Skyrme forces is not necessarily realistic the dependence on the n-p asymmetry
exhibit a more consistent behaviour. The isospin symmetry energy coefficient
(s.e.c.) increases as the n-p asymmetry acquires higher values whereas the
isoscalar s.e.c. decreases. Some consequences for the Supernovae mechanism are
discussed.


title: Diffractive Dijet Production and Nuclear Shadowing in pA Interactions

abstract:
  We study the implications of non-universality observed recently in e p and
pbar p diffraction for nuclear shadowing and diffractive dijet production in pA
collisions.


title:
Comment on ``Structure of exotic nuclei and superheavy elements in a
  relativistic shell model''

abstract:
  A recent paper [M. Rashdan, Phys. Rev. C 63, 044303 (2001)] introduces the
new parameterization NL-RA1 of the relativistic mean-field model which is
claimed to give a better description of nuclear properties than earlier ones.
Using this model ^{298}114 is predicted to be a doubly-magic nucleus. As will
be shown in this comment these findings are to be doubted as they are obtained
with an unrealistic parameterization of the pairing interaction and neglecting
ground-state deformation.


title:
Parameter-Free Calculation of the Solar Proton Fusion Rate in Effective
  Field Theory

abstract:
  Spurred by the recent complete determination of the weak currents in
two-nucleon systems up to ${\cal O}(Q^3)$ in heavy-baryon chiral perturbation
theory, we carry out a parameter-free calculation of the solar proton fusion
rate in an effective field theory that combines the merits of the standard
nuclear physics method and systematic chiral expansion. Using the tritium
beta-decay rate as an input to fix the only unknown parameter in the effective
Lagrangian, we can evaluate with drastically improved precision the ratio of
the two-body contribution to the well established one-body contribution; the
ratio is determined to be (0.86\pm 0.05) %. This result is essentially
independent of the cutoff parameter for a wide range of its variation (500 MeV
\le \Lambda \le 800 MeV), a feature that substantiates the consistency of the
calculation.


title: Spin susceptibility of neutron matter at zero temperature

abstract:
  The Auxiliary Field Diffusion Monte Carlo method is applied to compute the
spin susceptibility and the compressibility of neutron matter at zero
temperature. Results are given for realistic interactions which include both a
two-body potential of the Argonne type and the Urbana IX three-body potential.
Simulations have been carried out for about 60 neutrons. We find an overall
reduction of the spin susceptibilty by about a factor 3 with respect to the
Pauli susceptibility for a wide range of densities. Results for the
compressibility of neutron matter are also presented and compared with other
available estimates obtained for semirealistic nucleon-nucleon interactions by
using other techniques.


title:
Recent developments in the dynamical and unitary isobar models for pion
  electromagnetic production

abstract:
  gamma N->Delta transition form factors and threshold pi^0 photo- and
electroproduction are studied with the new version of MAID and a dynamical
model. By re-analyzing the recent Jlab data on p(e,e'p) pi^0 at Q^2 = 2.8 and
4.0 (GeV/c)^2, we find that the hadronic helicity conservation is not yet
observed in this region of Q^2. The extracted R_{EM}, starting from a small and
negative value at the real photon point, actually exhibits a clear tendency to
cross zero and change sign as Q^2 increases, while the absolute value of R_{SM}
is strongly increasing. Our analysis indicates that A_{1/2} and S_{1/2}, but
not A_{3/2}, starts exhibiting the pQCD scaling behavior at about Q^2 = 2.5
(GeV/c)^2. For the pi^0 photo- and electroproduction near threshold, results
obtained within the dynamical model with the use of a meson-exchange pi N model
for the final state interaction are in as good agreement with the data as ChPT.


title: Dynamical meson-baryon resonances with chiral Lagrangians

abstract:
  The s-wave meson-baryon interaction is studied using the lowest-order chiral
Lagrangian in a unitary coupled-channels Bethe-Salpeter equation. In the
strangeness $S=-1$ sector the low-energy $K^- p$ dynamics leads to the
dynamical generation of the $\Lambda(1405)$ as a ${\bar K}N$ state, along with
a good description of the $K^- p$ scattering observables. At higher energies,
the $\Lambda(1670)$ is also found to be generated dynamically as a $K \Xi$
quasibound state for the first time. For strangeness S=0, it is the
$S_{11}(1535)$ resonance that emerges from the coupled-channels equations,
leading to a satisfactory description of meson-baryon scattering observables in
the energy region around the $S_{11}(1535)$. We speculate on the possible
dynamical generation of $\Xi$ resonances within the chiral $S=-2$ sector as
${\bar K} \Lambda$ or ${\bar K} \Sigma$ quasibound states.


title: The Quenching of the Axial Coupling in Nuclear and Neutron-Star Matter

abstract:
  Using a chirally invariant effective Lagrangian, we calculate the density and
isospin dependences of the in-medium axial coupling, $g_A^*$, in spatially
uniform matter present in core collapse supernovae and neutron stars. The
quenching of $g_A^*$ with density in matter with different proton fractions is
found to be similar. However, our results suggest that the quenching of the
nucleon's $g_A^*$ in matter with hyperons is likely to be significantly greater
than in matter with nucleons only.


title: Vector meson photoproduction in the quark model

abstract:
  We present a quark model study of the $\omega$ meson photoproduction near
threshold. With a limited number of parameters, all the data in history are
reproduced. The roles played by the {\it s}- and {\it u}-channel processes
(resonance excitations and nucleon pole terms), as well as the {\it t}-channel
{\it natural} (Pomeron) and {\it unnatural} parity (pion) exchanges are
clarified. This approach provides a framework for systematic study of vector
meson photoproduction near threshold.


title: Soft QCD Modeling of Meson Electromagnetic Form Factors

abstract:
  We summarize recent progress in soft QCD modeling based on the set of
Dyson--Schwinger equations truncated to ladder-rainbow level. We pay particular
attention to electromagnetic elastic and transition form factors of the pion.
This covariant approach accommodates quark confinement and implements the QCD
one-loop renormalization group behavior. The dressed quark propagators are
compared to the most recent lattice-QCD data.


title: Relativistic approaches to structure functions of nuclei

abstract:
  We employ a propagator technique to derive a new relativistic $1/\qq$
expansion of the structure function of a nucleus, composed of point-nucleons.
We exploit non-relativistic features of low-momentum nucleons in the target and
only treat relativistically the nucleon after absorption of a high-momentum
virtual photon. The new series permits a 3-dimensional reduction of each term
and a formal summation of all Final State Interaction terms. We then show that
a relativistic structure function can be obtained from its non-relativistic
analog by a mere change of a scaling variable and an addition of an energy
shift. We compare the obtained result with an ad hoc generalized
Gersch-Rodriguez-Smith theory, previously used in computations of nuclear
structure functions.


title: Deformed Boson Scheme in Time-Dependent Variational Method. I

abstract:
  Various aspects of the deformed boson scheme are investigated with aiming of
applying to the time-dependent variational method for many-boson system. The
case of the multiboson states is also discussed. In analogy with the
time-dependent Hartree-Fock theory in many-fermion system, the classical aspect
of the deformed boson is discussed.


title: Deformed Boson Scheme in Time-Dependent Variational Method. II

abstract:
  In this paper as a continuation of Part I, the case of two kinds of boson
operators is treated. The deformation of the coherent states for the su(2)- and
the su(1,1)-algebra and their related deformed algebras are discussed in
various forms including the most popular form.


title: Relativistic pionic effects in quasielastic electron scattering

abstract:
  The impact of relativistic pionic correlations and meson-exchange currents on
the response functions for electromagnetic quasielastic electron scattering
from nuclei is studied in detail. Results in first-order perturbation theory
are obtained for one-particle emission electronuclear reactions within the
context of the relativistic Fermi gas model. Improving upon previous analyses
where non-relativistic reductions of the currents were performed, here a fully
relativistic analysis in which both forces and currents are treated
consistently is presented. Lorentz covariance is shown to play a crucial role
in enforcing the gauge invariance of the theory. Effects stemming uniquely from
relativity in the pionic correlations are identified and, in particular, a
comprehensive study of the self-energy contributions and of the currents
associated with the pion is presented. First- and second-kind scaling for high
momentum transfer is investigated.


title:
Microscopic coloured quark-dynamics in the soft non-perturbative regime
  -- Description of hadron formation in relativistic S+Au collisions at CERN

abstract:
  The quark-molecular-dynamics model is used to study microscopically the
dynamics of the coloured quark phase and the subsequent hadron formation in
relativistic S+Au collisions at the CERN-SPS. Particle spectra and hadron
ratios are compared to both data and the results of hadronic transport
calculations. The non-equilibrium dynamics of hadronization and the loss of
correlation among quarks are studied.


title: Event anisotropy in 4.2A GeV/c C+C collisions

abstract:
  The directed and elliptic flow of protons and negative pions in 4.2A GeV/c
C+C collisions is studied using the Fourier analysis of azimuthal
distributions. It is found that the protons exhibit pronounced directed flow,
while the flow of pions is either non existent or too weak to be detected
experimentally. Also, it is found that in the entire rapidity interval the
elliptic flow is very small if not zero. These results are confirmed by the
Quark-Gluon-String Model (QGSM) and the relativistic transport model (ART 1.0),
except that these models predict very weak antiflow of pions. The more detailed
comparison with the QGSM suggests that the decay of resonances and rescattering
of secondaries dominantly determine the proton and negative pion flow at this
energy.


title: Spectral Red-Shift Versus Broadening from Photon and Dilepton Spectra

abstract:
  We estimate the photon and dilepton emission rates from hot hadronic matter
with in-medium spectral shift and broadening of vector mesons. It is observed
that both the WA98 photon data and CERES/NA45 dilepton data can be well
reproduced with similar initial conditions. The freeze-out condition has been
constrained by the transverse mass spectra of pions and protons measured by the
NA49 collaboration. We argue that simultaneous measurement of the $p_T$ spectra
of single photons as well as invariant mass distribution of dileptons is
crucial to understand the in-medium spectral function of the vector mesons.


title: Meson Properties in Dense Hadronic Matter

abstract:
  The medium modification of mesons in dense hadronic matter is discussed with
a focus on the relationship to the chiral structure of the non-perturbative QCD
vacuum.


title: J/$\psi$ production and suppression in nuclear collisions

abstract:
  In terms of a new QCD factorization formula for J/$\psi$ production, we
calculate the J/$\psi$ suppression in nuclear collisions by including the
multiple scattering between the pre-J/$\psi$ partonic states and the nuclear
medium. We find agreement with all data on J/$\psi$ suppression in
hadron-nucleus and nucleus-nucleus collisions, except a couple of points (the
``second drop'') at the highest $E_T$ bins of the new NA50 data.


title:
Transverse momentum fluctuations due to temperature variation in
  high-energy nuclear collisions

abstract:
  The event-by-event p_T-fluctuations due to the temperature variation are
considered. The so-called Phi-measure is computed and shown to be a linear
function of the temperature variance. The fluctuations of temperature naturally
explain the data on Phi(p_T) in proton-proton and central Pb-Pb collisions but
independent measurements of the temperature fluctuations are needed to confirm
the explanation. Feasibility of such an event-by-event measurement is
discussed.


title: Deuteron distribution in nuclear matter

abstract:
  We analyze the properties of deuteron-like structures in infinite, correlated
nuclear matter, described by a realistic hamiltonian containing the Urbana
$v_{14}$ two-nucleon and the Urbana TNI many-body potentials. The distribution
of neutron-proton pairs, carrying the deuteron quantum numbers, is obtained as
a function of the total momentum by computing the overlap between the nuclear
matter in its ground state and the deuteron wave functions in correlated basis
functions theory. We study the differences between the S- and D-wave components
of the deuteron and those of the deuteron-like pair in the nuclear medium. The
total number of deuteron type pairs is computed and compared with the
predictions of Levinger's quasideuteron model. The resulting Levinger's factor
in nuclear matter at equilibrium densityis 11.63. We use the local density
approximation to estimate the Levinger's factor for heavy nuclei, obtaining
results which are consistent with the available experimental data from
photoreactions.


title: Parton Energy Loss with Detailed Balance

abstract:
  Stimulated gluon emission and thermal absorption in addition to induced
radiation are considered for an energetic parton propagating inside a quark-
gluon plasma. In the presence of thermal gluons, stimulated emission reduces
while absorption increases the parton's energy. The net effect is a reduction
of the parton energy loss. Though decreasing asymptotically as $T/E$ with the
parton energy, the relative reduction is found to be important for intermediate
energies. The modified energy dependence of the energy loss will affect the
shape of suppression of moderately high $p_T$ hadrons due to jet quenching in
high-energy heavy-ion collisions.


title:
Nucleon momentum distribution in deuteron and other nuclei within the
  light-front dynamics method

abstract:
  The relativistic light-front dynamics (LFD) method has been shown to give a
correct description of the most recent data for the deuteron monopole and
quadrupole charge form factors obtained at the Jefferson Laboratory for elastic
electron-deuteron scattering for six values of the squared momentum transfer
between 0.66 and 1.7 (GeV/c)$^{2}$. The good agreement with the data is in
contrast with the results of the existing non-relativistic approaches. In this
work we firstly make a complementary test of the LFD applying it to calculate
another important characteristic, the nucleon momentum distribution $n(q)$ of
the deuteron using six invariant functions $f_{i}$ $(i=1,...,6)$ instead of two
($S$- and $D$-waves) in the nonrelativistic case. The comparison with the
$y$-scaling data shows the decisive role of the function $f_{5}$ which at
$q\geq$ 500 MeV/c exceeds all other $f$-functions (as well as the $S$- and
$D$-waves) for the correct description of $n(q)$ of the deuteron in the
high-momentum region. Comparison with other calculations using $S$- and
$D$-waves corresponding to various nucleon-nucleon potentials is made.
Secondly, using clear indications that the high-momentum components of $n(q)$
in heavier nuclei are related to those in the deuteron, we develop an approach
within the natural orbital representation to calculate $n(q)$ in $(A,Z)$-nuclei
on the basis of the deuteron momentum distribution. As examples, $n(q)$ in
$^{4}$He, $^{12}$C and $^{56}$Fe are calculated and good agreement with the
$y$-scaling data is obtained.


title:
Multipole analysis for pion photoproduction with MAID and a dynamical
  models

abstract:
  Results of new analysis of pion photoproduction data obtained with Dynamical
and MAID models are presented


title: Fluctuation probes of quark deconfinement

abstract:
  The magnitude of the local fluctuations of the net baryon number and electric
charge differs widely between the confined and deconfined phases, and the
difference is partially frozen at an early stage in relativistic heavy ion
collisions. These fluctuations may thus be useful probes of the temporary
formation of a deconfined state in such collisions.


title:
Longitudinal and Transverse Quasi-Elastic Response Functions of Light
  Nuclei

abstract:
  The $^3$He and $^4$He longitudinal and transverse response functions are
determined from an analysis of the world data on quasi-elastic inclusive
electron scattering. The corresponding Euclidean response functions are derived
and compared to those calculated with Green's function Monte Carlo methods,
using realistic interactions and currents. Large contributions associated with
two-body currents are found, particularly in the $^4$He transverse response, in
agreement with data. The contributions of two-body charge and current operators
in the $^3$He, $^4$He, and $^6$Li response functions are also studied via
sum-rule techniques. A semi-quantitative explanation for the observed
systematics in the excess of transverse quasi-elastic strength, as function of
mass number and momentum transfer, is provided. Finally, a number of model
studies with simplified interactions, currents, and wave functions is carried
out to elucidate the role played, in the full calculation, by tensor
interactions and correlations.


title: Anomalous Spectral Statistics of the Asymmetric Rotor Model

abstract:
  We investigate the spectral statistics of the asymmetric rotor model
(triaxial rigid rotator). The asymmetric top is classically integrable and,
according to the Berry-Tabor theory, its spectral statistics should be
Poissonian. Surprisingly, our numerical results show that the nearest neighbor
spacing distribution $P(s)$ and the spectral rigidity $\Delta_3(L)$ do not
follow Poisson statistics.


title:
QCD condensates and hadron parameters in nuclear matter: self-consistent
  treatment, sum rules and all that

abstract:
  We review various approaches to the calculation of QCD condensates and of the
nucleon characteristics in nuclear matter. We show the importance of their
self-consistent treatment. The first steps in such treatment appeared to be
very instructive. It is shown that the alleged pion condensation anyway can not
take place earlier than the restoration of the chiral symmetry. We demonstrate
how the finite density QCD sum rules for nucleons work and advocate their
possible role in providing an additional bridge between the condensate and
hadron physics.


title: Description of the RHIC p_T-spectra in a thermal model with expansion

abstract:
  The assumption of simultaneous chemical and thermal freeze-outs of the hadron
gas leads to a surprisingly accurate, albeit entirely conventional, explanation
of the recently-measured RHIC pT spectra. The original thermal spectra are
supplied with secondaries from decays of all resonances, and subsequently
folded with a suitably parameterized expansion involving longitudinal and
transverse flow. The predictions of this thermal approach, with various
parametrizations for the expansion, are in a striking quantitative agreement
with the data in the whole available range of 0 < pT < 3.5GeV.


title: Singular Character of Critical Points in Nuclei

abstract:
  The concept of critical points in nuclear phase transitional regions is
discussed from the standpoints of Q-invariants, simple observables and wave
function entropy. It is shown that these critical points very closely coincide
with the turning points of the discussed quantities, establishing the singular
character of these points in nuclear phase transition regions between
vibrational and rotational nuclei, with a finite number of particles.


title: Interactions between Octet Baryons in the SU_6 Quark model

abstract:
  The baryon-baryon interactions for the complete baryon octet (B_8) are
investigated in a unified framework of the resonating-group method, in which
the spin-flavor SU_6 quark-model wave functions are employed. Model parameters
are determined to reproduce properties of the nucleon-nucleon system and the
low-energy cross section data for the hyperon-nucleon interaction. We then
proceed to explore B_8 B_8 interactions in the strangeness S=-2, -3 and -4
sectors. The S-wave phase-shift behavior and total cross sections are
systematically understood by 1) the spin-flavor SU_6 symmetry, 2) the special
role of the pion exchange, and 3) the flavor symmetry breaking.


title:
pi^0 -> gamma gamma*, omega -> pi^0 gamma*, and rho -> pi gamma* decays
  in nuclear medium

abstract:
  We calculate the medium modification of the pi-omega-rho vertex and analyze
its significance for the pi^0 -> gamma gamma*, omega -> pi^0 gamma*, and rho ->
pi gamma* decays in nuclear matter. We use a relativistic hadronic approach at
zero temperature and in the leading-density limit, and consider decays of
particles at rest with respect to the medium. It is shown that for the pi^0 ->
gamma gamma* the effects of the Delta isobar cancel almost exactly the effects
of the nucleon ph excitations, such that the net medium effect is small. On the
contrary, for the decays omega -> pi^0 gamma* and rho -> pi gamma* we find a
sizeable increase of the partial widths at virtualities of the photon in the
range 0.3-0.6 GeV. The effect has direct significance for the calculation of
dilepton yields from the Dalitz decays in relativistic heavy-ion collisions.


title: Novel Weak Decays in Doubly Strange Systems

abstract:
  The strangeness-changing ($\Delta S = 1$) weak baryon-baryon interaction is
studied through the nonmesonic weak decay of double-$\Lambda$ hypernuclei.
Besides the usual nucleon-induced decay $\Lambda N \to N N$ we discuss novel
hyperon-induced decay modes $\Lambda \Lambda \to \Lambda N$ and $\Lambda
\Lambda \to \Sigma N$. These reactions provide unique access to the exotic
$\Lambda \Lambda$K and $\Lambda \Sigma$K vertices which place new constraints
on Chiral Pertubation Theory ($\chi$PT) in the weak SU(3) sector. Within a
meson-exchange framework, we use the pseudoscalar $\pi,\eta,K$ octet for the
long-range part while parametrizing the short-range part through the vector
mesons $\rho, \omega, K^*$. Realistic baryon-baryon forces for the $S=0,-1$ and
-2 sectors account for the strong interaction in the initial and final states.
For $^6_{\Lambda \Lambda}$He the new hyperon-induced decay modes account for up
to 4% of the total nonmesonic decay rate. Predictions are made for all possible
nonmesonic decay modes.


title:
Do Hadronic Charge Exchange Reactions Measure Electroweak L = 1
  Strength?

abstract:
  An eikonal model has been used to assess the relationship between calculated
strengths for first forbidden beta decay and calculated cross sections for
(p,n) charge exchange reactions. It is found that these are proportional for
strong transitions, suggesting that hadronic charge exchange reactions may be
useful in determining the spin-dipole matrix elements for astrophysically
interesting leptonic transitions.


title: Phenomenological study of hadron interaction models

abstract:
  We present a phenomenological study of three models with different effective
degrees of freedom: a Goldstone Boson Exchange (GBE) model which is based on
quark-meson couplings, the quark delocalization, color screening model (QDCSM)
which is based on quark-gluon couplings with delocalized quark wavefunctions,
and the Fujiwara-Nijmegen (FN) mixed model which includes both quark-meson and
quark-gluon couplings. We find that for roughly two-thirds of 64 states
consisting of pairs of octet and decuplet baryons, the three models predict
similar effective baryon-baryon interactions. This suggests that the three very
different models, based on different effective degrees of freedom, are
nonetheless all compatible with respect to baryon spectra and baryon-baryon
interactions. We also discuss the differences between the three models and
their separate characteristics.


title: The equivalence theorem and the Bethe-Salpeter equation

abstract:
  We solve the Bethe-Salpeter equation for two-particle scattering in a
field-theoretical model using two lagrangians related by a field
transformation. The kernel of the equation consists of the sum of all
tree-level diagrams for each lagrangian. The solutions differ even if all four
external particles are put on the mass shell, which implies that observables
calculated by solving the Bethe-Salpeter equation depend on the representation
of the theory. We point out that this violation of the equivalence theorem has
a simple explanation and should be expected for any Bethe-Salpeter equation
with a tree-level kernel. Implications for dynamical models of hadronic
interactions are discussed.


title: Neutrino-nucleon scattering rate in proto neutron star matter

abstract:
  We present a calculation of the neutrino-nucleon scattering cross section
which takes into account the nuclear correlations in the relativistic random
phase approximation. Our approach is based on a quantum hadrodynamics model
with exchange of $\sigma$, $\omega$, $\pi$, $\rho$ and $\delta$ mesons. In view
of applications to neutrino transport in the final stages of supernova
explosion and protoneutron star cooling, we study the evolution of the neutrino
mean free path as a function of density, proton-neutron asymmetry and
temperature. Special attention was paid to the issues of renormalization of the
Dirac sea, residual interactions in the tensor channel and meson mixing. It is
found that RPA corrections, with respect to the mean field approximation,
amount to only 10% to 15% at high density.


title: Multipole Analysis of a Benchmark Data Set for Pion Photoproduction

abstract:
  We have fitted low- and medium-energy benchmark datasets employing methods
used in the MAID/SAID and dynamical model analyses. Independent fits from the
Mainz, RPI, Yerevan, and Kharkov groups have also been performed over the
low-energy region. Results for the multipole amplitudes are compared in order
to gauge the model-dependence of such fits, given identical data and a single
method for error handling.


title: A(e,e'p) reactions at GeV energies

abstract:
  An unfactorized and relativistic framework for calculating A(e,e'p)
observables at typical JLAB energies is presented. Results of (e,e'p) model
calculations for the target nuclei ^{12}C and ^{16}O are presented and compared
to data from SLAC and JLAB.


title:
The time-dependent relativistic mean-field theory and the random phase
  approximation

abstract:
  The Relativistic Random Phase Approximation (RRPA) is derived from the
Time-dependent Relativistic Mean Field (TD RMF) theory in the limit of small
amplitude oscillations. In the no-sea approximation of the RMF theory, the RRPA
configuration space includes not only the usual particle-hole states, but also
a-h configurations, i.e. pairs formed from occupied states in the Fermi sea and
empty negative-energy states in the Dirac sea. The contribution of the negative
energy states to the RRPA matrices is examined in a schematic model, and the
large effect of Dirac sea states on isoscalar strength distributions is
illustrated for the giant monopole resonance in 116Sn. It is shown that,
because the matrix elements of the time-like component of the vector meson
fields which couple the a-h configurations with the ph-configurations are
strongly reduced with respect to the corresponding matrix elements of the
isoscalar scalar meson field, the inclusion of states with unperturbed energies
more than 1.2 GeV below the Fermi energy has a pronounced effect on giant
resonances with excitation energies in the MeV region. The influence of nuclear
magnetism, i.e. the effect of the spatial components of the vector fields is
examined, and the difference between the non-relativistic and relativistic RPA
predictions for the nuclear matter compression modulus is explained.


title:
Renormalization of the Hartree-Fock-Bogoliubov Equations in the Case of
  a Zero Range Pairing Interaction

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 dependent running coupling constant.


title: Physics of Antiproton Nuclear Interactions near Threshold

abstract:
  Antiproton-nucleus optical potentials fitted to $\bar p$-atom level shifts
and widths are used to calculate the recently reported very low energy
($p_{L}<100$ MeV/c) $\bar p$ cross sections for annihilation on light nuclei.
The apparent suppression of annihilation upon increasing the atomic charge $Z$
and mass number $A$ is resolved as due to the strong effective repulsion
produced by the very absorptive optical potential which keeps the $\bar
p$-nucleus wavefunction substantially outside the nuclear surface, so that the
resulting reaction cross section saturates as function of the strength of Im
$V_{{\rm opt}}$. This feature, for $E >0$, parallels the recent prediction, for
$E < 0$, that the level widths of $\bar p$ atoms saturate and, hence, that
$\bar p$ deeply bound atomic states are relatively narrow. Predictions are made
for $\bar p$ annihilation cross sections over the entire periodic table at
these very low energies and the systematics of the calculated cross sections as
function of $A$, $Z$ and $E$ are discussed and explained in terms of a
Coulomb-modified strong-absorption model. Finally, optical potentials which fit
simultaneously low-energy $\bar p - ^4$He observables for $E < 0$ as well as
for $E > 0$ are used to assess the reliability of extracting Coulomb modified
$\bar p$ nuclear scattering lengths directly from the data.


title: Restoration of broken symmetries in Self-Consistent RPA

abstract:
  It is shown that the Self-Consistent RPA (SCRPA) approach allows in a very
natural way to restore symmetries, spontaneously broken on the mean field
level. This is achieved via the introduction of a second Lagrange multiplier
which constrains the variance of the symmetry operator to zero. This important
feature of SCRPA, here pointed out for the first time, is illustrated employing
a simplified model of the nuclear superfluidity.


title:
Description of Double Giant Dipole Resonance within the Phonon Damping
  Model

abstract:
  In a recent Letter [1] an overall agreement with the experimental data for
the excitation of the single and double giant dipole resonances in relativistic
heavy ion collision in 136Xe and 208Pb nuclei has been reported. We point out
that this agreement is achieved by a wrong calculation of the DGDR excitation
mechanism. We also argue that the agreement with the data for the widths of
resonances is achieved by an unrealistically large value of a model parameter.
  [1] Nguyen Dinh Dang, Vuong Kim Au, and Akito Arima, Phys. Rev. Lett. 85
(2000) 1827.


title:
Charged Multiplicities at SPS and RHIC and consequences for $J/\psi$
  suppression

abstract:
  Hadron multiplicities in nucleus--nucleus interactions are calculated in the
Dual Parton Model and its dependence on the number of collisions and the number
of participants is analyzed. Shadowing corrections are calculated as a function
of impact parameter and the multiplicity per participant as a funtion of
centrality is found to be in agreement with experiment at SPS and RHIC
energies. The obtained results are used to compute the $J/\psi$ suppression in
a comover approach.


title:
Heavy Quarkonium Dissociation Cross Sections in Relativistic Heavy-Ion
  Collisions

abstract:
  Many of the hadron-hadron cross sections required for the study of the
dynamics of matter produced in relativistic heavy-ion collisions can be
calculated using the quark-interchange model. Here we evaluate the low-energy
dissociation cross sections of $J/\psi$, $\psi'$, $\chi$, $\Upsilon$, and
$\Upsilon'$ in collision with $\pi$, $\rho$, and $K$, which are important for
the interpretation of heavy-quarkonium suppression as a signature for the quark
gluon plasma. These comover dissociation processes also contribute to
heavy-quarkonium suppression, and must be understood and incorporated in
simulations of heavy-ion collisions before QGP formation can be established
through this signature.


title: The relativistic spectroscopy of rotating bodies

abstract:
  Mutual dependencies of mass and orbital moment increase for rotating bodies
of various configurations (a string with uniform mass distribution, a string
with squared mass distribution or a sphere with uniform mass distribution,
double system of point masses) are considered in quasiclassical approximation.
Results are used for analysis of meson, baryon resonances of rotating nature,
and also for dipion and dinucleon resonances. For oneparticle resonances a
string configuration with squared mass distribution is has been chosen. Radius
values and their possible changes with spin increase are obtained. At this, in
particular, for proton and $\delta$-isobar, which are the founders of rotating
bands, values 0.45 and 0.63 are defined, respectively. Dipion and dinucleon
resonances are pre-sented as two rotating point bodies at distances of some
fermy. Each of reso-nances is located in four rotary bands. Possible reasons of
formation of some rotary bands for these resonances are discussed.


title: Fluctuations of the quark densities in nuclei

abstract:
  We study the static scalar susceptibility of the nuclear medium, i.e., the
change of the quark condensate for a small modification of the quark mass. In
the linear sigma model it is linked to the in-medium sigma propagator. At
ordinary nuclear densities, when chiral symmetry is spontaneously broken, the
scalar susceptibility is distinct from the pseudoscalar one, which is linked to
the fluctuations of the quark pseudoscalar density. We show that the
pseudoscalar one, which is large in the vacuum, owing to the smallness of the
pion mass, follows the density evolution of the quark condensate and thus
decreases. The scalar one instead increases due to the mixing with the softer
modes of the nucleon-hole excitations. At normal nuclear matter density the two
susceptibilities become much closer, a partial chiral symmetry restoration
effect as they become equal when the full restoration is achieved.


title:
`` $\Lambda - \Sigma$ conversion in $^4_{\Lambda}$He and $^4_{\Lambda}$H
  based on four-body calculation

abstract:
  Precise four-body calculations for $^4_{\Lambda}$He and $^4_{\Lambda}$H have
been performed in the framework of the variational method with
Jacobian-coordinate Gaussian-basis functions. All the rearrangement channels of
both $NNN \Lambda$ and $NNN \Sigma$ are explicitly taken into account for the
first time with the use of realistic $NN$ and $YN$ interactions. The role of
$\Lambda$-$\Sigma$ conversion and the amount of the virtual $\Sigma$-component
in $^4_{\Lambda}$He and $^4_{\Lambda}$H are discussed.


title: Microscopic derivation of pion-nucleon and pion-Delta scattering lengths

abstract:
  A general expression for the $\pi -N$ and $\pi-\Delta $ scattering lengths is
derived in the framework of a microscopic calculation. Annihilation, negative
energy wave-functions and spontaneous chiral symmetry are included
consistently. The point-like limit is used to calculate the scattering lengths.


title: Lectures on the Theory of High Energy A+A at RHIC

abstract:
  In these lectures aspects of current theory used to interpret the preliminary
data on ultra-relativistic nuclear collisions at RHIC energies in terms of the
physical properties of QCD matter at extreme densities are introduced. Topics
include: What are the physics questions at SPS and RHIC?, Geometrical vs
Dynamical features of A+A, The interplay of computable Hard pQCD vs
phenomenological Soft dynamics, Baryon number transport and Junctions, How can
we compute and get experimental control over the initial conditions?, How to
reconcile apparent hydrodynamic behavior with partonic/hadronic transport
theory. I use the Preliminary RHIC data available up to June 1,2001 to
illustrate these topics. Since the main new observable at RHIC relative to SPS
is jet quenching, I elaborate on this ``tomographic'' probe of ultra-dense
matter. The possible discovery of jet quenching at RHIC by STAR and PHENIX is
highlighted.


title: Multistrange baryon production in relativistic heavy ion collisions

abstract:
  Using a multiphase transport model, we study the production of multistrange
baryons from the hadronic matter formed in relativistic heavy ion collisions.
The mechanism we introduce is the strangeness-exchange reactions between
antikaons and hyperons. We find that these reactions contribute significantly
to the production of multistrange baryons in heavy ion collisions at SPS
energies, which has been found to be appreciably enhanced. We have also made
predictions for multistrange baryon production in heavy ion collisions at RHIC
and found a similar enhancement.


title: The effect of finite-range interactions in classical transport theory

abstract:
  The effect of scattering with non-zero impact parameters between consituents
in relativistic heavy ion collisions is investigated. In solving the
relativistic Boltzmann equation, the characteristic range of the collision
kernel is varied from approximately one fm to zero while leaving the mean-free
path unchanged. Modifying this range is shown to significantly affect spectra
and flow observables. The finite range is shown to provide effective
viscosities, shear, bulk viscosity and heat conductivity, with the viscous
coefficients being proportional to the square of the interaction range.


title: Propagation of neutral mesons in asymmetric nuclear matter

abstract:
  We calculate dispersion relations and propagators for the $\sigma$, $\omega$,
$\rho$ and $\delta$ mesons in relativistic nuclear matter with a proton-neutron
asymmetry. In addition to the $\sigma$-$\omega$ and $\delta$-$\rho$ mixings
already present in symmetric matter, mixing occur between all components of the
$\sigma$-$\omega$-$\delta$-$\rho$ system when the proton fraction differs from
1/2.


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

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


title:
N=Z Waiting Point Nucleus $^{68}$Se: Collective Rotation and High-K
  Isomeric States

abstract:
  The structure of collective states and quasi-particle excitations in
$^{68}$Se is analyzed by using the projected shell model. It is found that the
$g_{9/2}$ orbitals play a decisive role for the structure of this nucleus. At
the prolate minimum, alignment of the low-K states causes the observed first
backbending in moment of inertia and we predict a second backbending that has
not yet been reported. At the oblate minimum, quasi-particles having high-K can
form long-lived isomeric states. The structure of $^{68}$Se is discussed with
respect to the isomers and their possible impact on the determination of its
nuclear mass.


title: Dispersion relations of mesons in symmetric nuclear matter

abstract:
  We calculate dispersion relations and propagators for the $\sigma$, $\omega$,
$\pi$, $\rho$, $\delta$, $\eta$ and $a_1$ mesons in relativistic, dense, hot,
symmetric nuclear matter. In addition to the usual mixing of the
$\sigma-\omega$ system, we obtain mixing of the $\delta$ with the longitudinal
$\rho$ mode and of the tranverse $\rho$ with the transverse $a_1$ mode.
Finally, the component of the $a_1$ polarization along the transferred momentum
modifies the in-medium pion propagator in a way similar to the Migdal contact
interaction, but with the opposite sign. The spurious pion condensate as well
as the additional contribution from the $a_1$ meson are removed by a contact
term. We compare two ways of implementing contact term subtraction.


title: Chiral corrections to kaon-nucleon scattering lengths

abstract:
  We calculate the threshold T-matrices of kaon-nucleon and antikaon-nucleon
scattering to one loop order in SU(3) heavy baryon chiral perturbation theory.
To that order the complex-valued isospin-1 $\bar KN$ threshold T-matrix can be
successfully predicted from the isospin-0 and 1 $KN$ threshold T-matrices. As
expected perturbation theory fails to explain the isospin-0 $\bar KN$ threshold
T-matrix which is completely dominated by the nearby subthreshold
$\Lambda^*(1405)$-resonance. Cancelations of large terms of second and third
chiral order are observed as they seem to be typical for SU(3) baryon chiral
perturbation theory calculations. We also give the kaon and eta loop
corrections to the $\pi N$ scattering lengths and we investigate $\pi\Lambda$
scattering to one-loop order. The second order s-wave low-energy constants are
all of natural size and do not exceed 1 GeV$^{-1}$ in magnitude.