title:
Effect of transients in nuclear fission on multiplicity of prescission
  neutrons

abstract:
  Transients in the fission of highly excited nuclei are studied in the
framework of the Langevin equation. Time-dependent fission widths are
calculated which show that after the initial transients, a steady flow towards
the scission point is established not only for nuclei which have fission
barriers but also for nuclei which have no fission barrier. It is shown from a
comparison of the transient time and the fission life time that fission changes
from a diffusive to a transient dominated process over a certain transition
region as a function of the spin of the fissioning nucleus. Multiplicities of
prescission neutrons are calculated in a statistical model with as well as
without a single swoop description of fission and they are found to differ in
the transition region. We however find that the difference is marginal and
hence a single swoop picture of fission though not strictly valid in the
transition region can still be used in the statistical model calculations.


title: Isobaric multiplet yrast energies and isospin non-conserving forces

abstract:
  The isovector and isotensor energy differences between yrast states of
isobaric multiplets in the lower half of the $pf$ region are quantitatively
reproduced in a shell model context. The isospin non-conserving nuclear
interactions are found to be at least as important as the Coulomb potential.
Their isovector and isotensor channels are dominated by J=2 and J=0 pairing
terms, respectively. The results are sensitive to the radii of the states,
whose evolution along the yrast band can be accurately followed.


title:
Partonic Effects on Pion Interferometry at the Relativistic Heavy Ion
  Collider

abstract:
  Using a multiphase transport (AMPT) model that includes both initial partonic
and final hadronic interactions, we study the pion interferometry at the
Relativistic Heavy Ion Collider. We find that the two-pion correlation function
is sensitive to the magnitude of the parton scattering cross section, which
controls the parton density at which the transition from the partonic to
hadronic matter occurs. Also, the emission source of pions is non-Gaussian,
leading to source radii that can be more than twice larger than the radius
parameters extracted from a Gaussian fit to the correlation function.


title: Sigma meson mass and width at finite density

abstract:
  The sigma meson mass and width are studied at finite baryonic density in the
framework of a chiral unitary approach which successfully reproduces the meson
meson phase shifts and generates the f0 and sigma resonances in vacuum.


title: Spin-polarized states of nuclear matter

abstract:
  The equations of state of spin-polarized nuclear matter and pure neutron
matter are studied in the framework of the Brueckner-Hartree-Fock theory
including a three-body force. The energy per nucleon $E_A(\delta)$ calculated
in the full range of spin polarization ${\delta} =
\frac{\rho_{\uparrow}-\rho_{\downarrow}}{\rho}$ for symmetric nuclear matter
and pure neutron matter fulfills a parabolic law. In both cases the
spin-symmetry energy is calculated as a function of the baryonic density along
with the related quantities such as the magnetic susceptibility and the Landau
parameter $G_0$. The main effect of the three-body force is to strongly reduce
the degenerate Fermi gas magnetic susceptibility even more than the value with
only two body force. The EOS is monotonically increasing with the density for
all spin-aligned configurations studied here so that no any signature is found
for a spontaneous transition to a ferromagnetic state.


title: Nonmesonic weak decay of light hypernuclei with coherent $\Sigma$ mixing

abstract:
  Nonmesonic weak decays of the A=4, and 5 hypernuclei are studied. The short
range parts of the hyperon-nucleon weak interactions are described by the
direct quark (DQ) weak transition potential, while the longer range
interactions are given by the $\pi$ and $K$ meson exchange processes. Virtual
$\Sigma$ mixings of the coherent type are found to give significant effects on
the decay rates of $^4_{\Lambda}{\rm He}$. A large violation of the $\Delta I =
1/2$ rule is predicted in the J=0 transition amplitudes.


title:
Low momentum nucleon-nucleon potentials with half-on-shell T-matrix
  equivalence

abstract:
  We study a method by which realistic nucleon-nucleon potentials V_NN can be
reduced, in a physically equivalent way, to an effective low-momentum potential
V-low-k confined within a cut-off momentum k-cut. Our effective potential is
obtained using the folded-diagram method of Kuo, Lee and Ratcliff, and it is
shown to preserve the half-on-shell T-matrix. Both the Andreozzi-Lee-Suzuki and
the Andreozzi-Krenciglowa-Kuo iteration methods have been employed in carrying
out the reduction. Calculations have been performed for the Bonn A and Paris NN
potentials, using various choices for k-cut such as 2 fm-1. The deuteron
binding energy, low-energy NN phase shifts, and the low-momentum half-on-shell
T-matrix given by V_NN are all accurately reproduced by V-low-k. Possible
applications of V-low-k directly to nuclear matter and nuclear structure
calculations are discussed.


title: Four-body cluster structure of $A=7-10$ double-$\Lambda$ hypernuclei

abstract:
  Energy levels of the double-$\Lambda$ hypernuclei
$_\Lambda^{}$$_\Lambda^7$He, $_\Lambda^{}$$_\Lambda^7$Li,
$_\Lambda^{}$$_\Lambda^8$Li, $_\Lambda^{}$$_\Lambda^9$Li,
$_\Lambda^{}$$_\Lambda^9$Be and $_\Lambda^{}$$_\Lambda^{10}$Be are predicted on
the basis of the $\alpha+x+\Lambda +\Lambda$ four-body model with $x=n, p, d,
t, ^3$He and $\alpha$, respectively.


title: Potential turning points in cluster radioactivity

abstract:
  Effects of various nuclear interaction potentials on the decay lifetimes and
the turning points of the WKB action integral has been studied. The microscopic
nuclear potential obtained by folding in the density distribution functions of
the two clusters with a realistic effective interaction has also been used to
calculate the turning points. Half lives of alpha and ^{20}O cluster emissions
from ^{228}Th have been calculated within the superasymmetric fission model
using various phenomenological and the microscopic double folding potentials.
Calculations of half lives with the microscopic double folding potentials are
found to be in good agreement with the observed experimental data. Present
calculations put the superasymmetric fission model on a firm theoretical basis.


title: Shadowing in photo-production : role of in-medium hadrons

abstract:
  We study the effects of in-medium hadronic properties on shadowing in
photon-nucleus interactions in Glauber model as well as in the multiple
scattering approach. A reasonable agreement with the experimental data is
obtained in a scenario of downward spectral shift of the hadrons. Shadowing is
found to be insensitive to the broadening of the spectral functions. An impact
parameter dependent analysis of shadowing might shed more light on the role of
in-medium properties of hadrons.


title: The Decoupling Problem at RHIC

abstract:
  We investigate whether it is possible to dynamically generate from classical
transport theory the observed surprising Rout ~ Rside in Au+Au at s^1/2 = 130A
GeV at RHIC. We obtained covariant solutions to the Boltzmann transport
equation via the MPC technique, for a wide range of partonic initial conditions
and opacities. We demonstrate that there exist transport solutions that yield a
freezeout distribution with Rout < Rside for Kperp > ~ 1.5 GeV. These solutions
correspond to continuous evaporation-like freezeout, where the emission
duration is comparable to the source size. Naively this would mean Rout >
Rside. Nevertheless, our sources exhibit Rout < Rside because they are narrower
in the 'out' than in the 'side' direction and, in addition, a positive x_out-t
correlation develops reducing Rout further.


title: Exotic clusters in the excited states of Be-12, Be-14 and B-15

abstract:
  The excited states of Be-12, Be-14 and B-15 were studied by an
antisymmetrized molecular dynamics method. The theoretical results reproduced
the energy levels of recently measured excited states of Be-12, and also
predicted rotational bands with innovative clustering structures in Be-12,
Be-14 and B-15. Clustering states with new exotic clusters (He-6, He-8 and
Li-9) were theoretically suggested. One new aspect in very neutron-rich nuclei
is a 6-nucleon correlation among 4 neutrons and 2 protons, which plays an
important role in the formation of He-6 clusters during clustering: 8He + 6He
of Be-14 and 9Li+6He of B-15.


title: Strange Disoriented Chiral Condensate

abstract:
  Disoriented chiral condensate can produce novel fluctuations of kaons as well
as pions. Robust statistical observables can be used to extract the novel
fluctuations from background contributions in K-short and K-charged correlation
measurements in nuclear collisions. To illustrate how this can be done, I
present new event-generator computations of these observables.


title:
Superpenetration of a high energy Q barQ bound state through random
  color fields

abstract:
  The transmission amplitude of a color dipole through a random external color
field is computed in the eikonal approximation in order to study the absorption
of high energy quarkonium by nuclear target. It is shown that the internal
color state of the dipole becomes randomized and all possible color states are
eventually equi-partitioned, while the probability of finding a color singlet
bound state attenuates not exponentially, but inversely proportional to the
distance L of the random field zone which the dipole has traveled.


title: Threshold $J/\psi-$ production in nucleon-nucleon collisions

abstract:
  We analyze $J/\psi-$ production in nucleon-nucleon collisions near threshold
in the framework of a general model independent formalism, which can be applied
to any reaction $N+N\to N+N+V^0$, where $V^0=\omega$, $\phi$, or $J/\psi$. Such
reactions show large isotopic effects: a large difference for $pp$- and
$pn$-collisions, which is due to the different spin structure of the
corresponding matrix elements. The analysis of the spin structure and of the
polarization observables is based on symmetry properties of the strong
interaction. Using existing experimental data on the different decays of
$J/\psi-$meson, we suggest a model for $N+N\to N+N+J/\psi$, based on
$t-$channel $\eta+\pi$-exchanges. We predict polarization phenomena for the
$n+p\to n+p+J/\psi$-reaction and the ratio of cross sections for $np$ and
$pp$-collisions. For the processes $\eta(\pi)+N\to N+J/\psi$ we apply two
different approaches: vector meson exchange and local four-particle
interaction. In both cases we find larger $J/\psi$-production in
$np$-collisions, with respect to $pp$-collisions.


title:
Partial conservation of the axial current and axial exchange currents in
  the nucleon

abstract:
  We discuss the axial form factors of the nucleon within the context of the
nonrelativistic chiral quark model. Partial conservation of the axial current
(PCAC) imposed at the quark operator level enforces an axial coupling for the
constituent quarks which is smaller than unity. This leads to an axial coupling
constant of the nucleon $g_A$ in good agreement with experiment. PCAC also
requires the inclusion of axial exchange currents. Their effects on the axial
form factors are analyzed. We find only small exchange current contributions to
$g_A$, which is dominated by the one-body axial current. On the other hand,
axial exchange currents give sizeable contributions to the axial radius of the
nucleon $r_A^2$, and to the non-pole part of the induced pseudoscalar form
factor $g_P$. For the latter, the confinement exchange current is the dominant
term.


title:
Covariant description of inelastic electron--deuteron
  scattering:predictions of the relativistic impulse approximation

abstract:
  Using the covariant spectator theory and the transversity formalism, the
unpolarized, coincidence cross section for deuteron electrodisintegration,
$d(e,e'p)n$, is studied. The relativistic kinematics are reviewed, and simple
theoretical formulae for the relativistic impulse approximation (RIA) are
derived and discussed. Numerical predictions for the scattering in the high
$Q^2$ region obtained from the RIA and five other approximations are presented
and compared. We conclude that measurements of the unpolarized coincidence
cross section and the asymmetry $A_\phi$, to an accuracy that will distinguish
between different theoretical models, is feasible over most of the wide
kinematic range accessible at Jefferson Lab.


title:
Isospin and density dependences of nuclear matter symmetry energy
  coefficients II

abstract:
  Symmetry energy coefficients of explicitly isospin asymmetric nuclear matter
at variable densities (from .5$\rho_0$ up to 2 $\rho_0$) are studied as
generalized screening functions. An extended stability condition for asymmetric
nuclear matter is proposed. We find the possibility of obtaining stable
asymmetric nuclear matter even in some cases for which the symmetric nuclear
matter limit is unstable. Skyrme-type forces are extensively used in analytical
expressions of the symmetry energy coefficients derived as generalized
screening functions in the four channels of the particle hole interaction
producing alternative behaviors at different $\rho$ and $b$ (respectively the
density and the asymmetry coefficient). The spin and spin-isospin coefficients,
with corrections to the usual Landau Migdal parameters, indicate the
possibility of occurring instabilities with common features depending on the
nuclear density and n-p asymmetry. Possible relevance for high energy heavy
ions collisions and astrophysical objects is discussed.


title: An Algebraic Pairing Model with Sp(4) Symmetry and its Deformation

abstract:
  A fermion realization of the compact symplectic sp(4) algebra provides a
natural framework for studying isovector pairing correlations in nuclei. While
these correlations manifest themselves most clearly in the binding energies of
0^+ ground states, they also have a large effect on the energies of excited
states, including especially excited 0^+ states. In this article we consider
non-deformed as well as deformed algebraic descriptions of pairing through the
reductions of sp_{(q)}(4) to different realizations of u_{(q)}(2) for single-j
and multi-j orbitals. The model yields a classification scheme for completely
paired 0^{+} states of even-even and odd-odd nuclei in the 1d_{3/2}, 1f_{7/2},
and 1f_{5/2}2p_{1/2}2p_{3/2}1g_{9/2} shells. Phenomenological non-deformed and
deformed isospin-breaking Hamiltonians are expressed in terms of the generators
of the dynamical symmetry groups Sp(4) and Sp_{q}(4). These Hamiltonians are
related to the most general microscopic pairing problem, including isovector
pairing and isoscalar proton-neutron interaction along with non-linear
interaction in the deformed extension. In both the non-deformed and deformed
cases the eigenvalues of the Hamiltonian are fit to the relevant Coulomb
corrected experimental 0^{+} energies and this, in turn, allows us to estimate
the interaction strength parameters, to investigate isovector-pairing
properties and symmetries breaking, and to predict the corresponding energies.
While the non-deformed theory yields results that are comparable to other
theories for light nuclei, the deformed extension, which takes into account
higher-order interactions between the particles, gives a better fit to the
data. The multi-shell applications of the model provide for reasonable
predictions of energies of exotic nuclei.


title:
Extraction of the n structure function $F_2^n$ from inclusive scattering
  data on composite nuclei

abstract:
  We consider a generalized convolution, linking Structure Functions (SF)
$F^N_2$ for nucleons, $F^A_2$ for a physical nucleus and $f^{PN,A}$ for a
nucleus, composed of point-nucleons. In order to extract $F_2^n$ we employ data
on $F_2^{p,A}$ and the computed $f^{PN,A}$. Only for $Q^2\approx 3.5 {\rm
GeV}^2$ do data permit the extraction of $F_2^A(x,3.5)$ over a sufficiently
wide $x$-range. Applying Mellin transforms, the above relation between SF turns
into an algebraic one, which one solves for the Mellin transform of the unknown
$F_2^n$. We present inversion methods leading to the desired $F_2^n$, all using
a parametrization for $C(x,Q^2)=F_2^n(x,Q^2)/F_2^p(x,Q^2)$. Imposing motivated
constraints, the simplest parametrization leaves one free parameter
$C(x=1,Q^2)$. For $Q^2= 3.5 {\rm GeV}^2$ its average over several targets and
different methods is $<C(1,3.5)>=0.54\pm0.03$. We argue that for the
investigated $Q^2$, $C(x\to 1,3.5)$ is determined by the nucleon-elastic ($NE$)
part of SF. The calculated value is near the extracted one and both are close
to the SU(6) limit 2/3.


title: Perturbative Effective Theory in an Oscillator Basis?

abstract:
  The effective interaction/operator problem in nuclear physics is believed to
be highly nonperturbative, requiring extended high-momentum spaces for accurate
solution. We trace this to difficulties that arise at both short and long
distances when the included space is defined in terms of a basis of harmonic
oscillator Slater determinants. We show, in the simplest case of the deuteron,
that both difficulties can be circumvented, yielding highly perturbative
results in the potential even for modest (~6hw) included spaces.


title: Learning from Dispersive Effects in the Nucleon Polarisabilities

abstract:
  A cartoon is drawn how and why to define and extract the energy dependence of
the nucleon polarisabilities from low energy Compton scattering on the nucleon.
The information dynamical polarisabilities contain about the low energy degrees
of freedom inside the nucleon is extracted by comparing the chiral effective
field theory calculation with dispersion theory results. Dynamical
polarisabilities do not contain more or less information than the corresponding
Compton scattering amplitudes, but as with any multipole decomposition, the
facts are more readily accessible and easier to interpret. Stringent
constraints for models and model-independent power countings of a low energy
effective field theory of the nucleon follow from their analysis.


title:
Correlations beyond the mean field in Magnesium isotopes: Angular
  momentum projection and configuration mixing

abstract:
  The quadrupole deformation properties of the ground and low-lying excited
states of the even-even Magnesium isotopes with N ranging from 8 to 28 have
been studied in the framework of the angular momentum projected generator
coordinate method with the Gogny force. It is shown that the N=8 neutron magic
number is preserved (in a dynamical sense) in \nuc{20}{Mg} leading to a
spherical ground state. For the magic numbers N=20 and N=28 this is not the
case and prolate deformed ground states are obtained. The method yields values
of the two neutron separation energies which are in much better agreement with
experiment than those obtained at the mean field level. It is also obtained
that \nuc{40}{Mg} is at the neutron dripline. Concerning the results for the
excitation energies of the $2^+$ excited states and their transition
probabilities to the ground state we observe a good agreement with the
available experimental data. On the theoretical side, we also present a
detailed justification of the prescription used for the density dependent part
of the interaction in our beyond-mean-field calculations.


title: Rotating Neutron Stars in a Chiral SU(3) Model

abstract:
  We study the properties of rotating neutron stars within a generalized chiral
SU(3)-flavor model. The influence of the rotation on the inner structure and
the hyperon matter content of the star is discussed. We calculate the Kepler
frequency and moments of inertia of the neutron star sequences. An estimate for
the braking index of the associated pulsars is given.


title: Selection rules in the double beta decay of deformed nuclei

abstract:
  The 2 nu double beta decay half-lives of six nuclei, whose decays were
previously reported as theoretically forbidden, are calculated by including the
pairing interaction, which mixes different occupations and opens up the
possibility of the decay. All allowed channels for the 0 nu double beta decay
are also computed. The estimated 2 nu double beta half-lives suggest that
measurements in 244Pu may find positive signals, and that planned experiments
would succeed in detecting the 2 nu double beta decay in 160Gd. Limits for the
zero neutrino mode, in the analyzed deformed emitters, are predicted.


title:
Probing the High Density Behaviour of Nuclear Symmetry Energy with High
  Energy Heavy-Ion Collisions

abstract:
  High energy heavy-ion collisions are proposed as a novel means to constrain
stringently the high density (HD) behaviour of nuclear symmetry energy. Within
an isospin-dependent hadronic transport model, it is shown for the first time
that the isospin asymmetry of the HD nuclear matter formed in high energy
heavy-ion collisions is uniquely determined by the HD behaviour of nuclear
symmetry energy. Experimental signatures in two sensitive probes, i.e., $\pi^-$
to $\pi^+$ ratio and neutron-proton differential collective flow, are also
investigated.


title: Vortex Excitations in $\alpha$ Cluster Condensed Nuclei

abstract:
  We point out an intriguing possibility that there exist topological
soliton-like excitations in nuclei with $\alpha$ cluster condensation. The
excitations are vortices in superfluid, a property possessed by such Bose
condensed nuclei. We show that the vortex-like states possess quantum numbers
$J^{P}=n^{(-1)^n}$ and energies $\sim $ several MeV, measured from the ground
state energies of the $n \alpha$ condensed states. We point out actual
candidates, for instance, $2^{+}(3 {MeV})$ for $^{8}$Be, $3^{-}(9.6 {MeV})$ for
$^{12}$C, etc, although the topological nature as a vortex is obscure in such
light nuclei.


title: Non-adiabatic corrections to elastic scattering of halo nuclei

abstract:
  We derive the formalism for the leading order corrections to the adiabatic
approximation to the scattering of composite projectiles. Assuming a two-body
projectile of core plus loosely-bound valence particle and a model (the core
recoil model) in which the interaction of the valence particle and the target
can be neglected, we derive the non-adiabatic correction terms both exactly,
using a partial wave analysis, and using the eikonal approximation. Along with
the expected energy dependence of the corrections, there is also a strong
dependence on the valence-to-core mass ratio and on the strength of the
imaginary potential for the core-target interaction, which relates to
absorption of the core in its scattering by the target. The strength and
diffuseness of the core-target potential also determine the size of the
corrections. The first order non-adiabatic corrections were found to be smaller
than qualitative estimates would expect. The large absorption associated with
the core-target interaction in such halo nuclei as Be11 kills off most of the
non-adiabatic corrections. We give an improved estimate for the range of
validity of the adiabatic approximation when the valence-target interaction is
neglected, which includes the effect of core absorption. Some consideration was
given to the validity of the eikonal approximation in our calculations.


title: Control of Quantum Systems

abstract:
  A quantum system subject to external fields is said to be controllable if
these fields can be adjusted to guide the state vector to a desired destination
in the state space of the system. Fundamental results on controllability are
reviewed against the background of recent ideas and advances in two seemingly
disparate endeavors: (i) laser control of chemical reactions and (ii) quantum
computation. Using Lie-algebraic methods, sufficient conditions have been
derived for global controllability on a finite-dimensional manifold of an
infinite-dimensional Hilbert space, in the case that the Hamiltonian and
control operators, possibly unbounded, possess a common dense domain of
analytic vectors. Some simple examples are presented. A synergism between
quantum control and quantum computation is creating a host of exciting new
opportunities for both activities. The impact of these developments on
computational many-body theory could be profound.


title:
Asymptotic Behavior of the Wave Packet Propagation through a Barrier:
  the Green's Function Approach Revisited

abstract:
  To model the decay of a quasibound state we use the modified two-potential
approach introduced by Gurvitz and Kalbermann. This method has proved itself
useful in the past for calculating the decay width and the energy shift of an
isolated quasistationary state. We follow the same approach in order to
propagate the wave-packet in time with the ultimate goal of extracting the
momentum-distribution of emitted particles. The advantage of the method is that
it provides the time-dependent wave function in a simple semi-analytic form. We
intend to apply this method to the modeling of metastable states for which no
direct integration of the time-dependent Schroedinger equation is available
today.


title:
The long journey from the giant-monopole resonance to the nuclear-matter
  incompressibility

abstract:
  Differences in the density dependence of the symmetry energy predicted by
nonrelativistic and relativistic models are suggested, at least in part, as the
culprit for the discrepancy in the values of the compression modulus of
symmetric nuclear matter extracted from the energy of the giant monopole
resonance in 208Pb. ``Best-fit'' relativistic models, with stiffer symmetry
energies than Skyrme interactions, consistently predict higher compression
moduli than nonrelativistic approaches. Relativistic models with compression
moduli in the physically acceptable range of K=200-300 MeV are used to compute
the distribution of isoscalar monopole strength in 208Pb. When the symmetry
energy is artificially softened in one of these models, in an attempt to
simulate the symmetry energy of Skyrme interactions, a lower value for the
compression modulus is indeed obtained. It is concluded that the proposed
measurement of the neutron skin in 208Pb, aimed at constraining the density
dependence of the symmetry energy and recently correlated to the structure of
neutron stars, will also become instrumental in the determination of the
compression modulus of nuclear matter.


title: Nuclear modifications of fragmentation functions and rescaling models

abstract:
  We discuss nuclear modification of fragmentation functions in the context of
the so-called ``rescaling models''. These models implement partial
deconfinement inside nuclei by modifying the fragmentation functions
perturbatively. We apply these models to the analysis of nuclear hadron
production in deep inelastic scattering processes at the HERMES and EMC
experiments.


title:
Relativistic Hartree-Bogoliubov model with density-dependent
  meson-nucleon couplings

abstract:
  The relativistic Hartree-Bogoliubov (RHB) model is extended to include
density dependent meson-nucleon couplings. The effective Lagrangian is
characterized by a phenomenological density dependence for the $\sigma$,
$\omega$ and $\rho$ meson-nucleon vertex functions, adjusted to properties of
nuclear matter and finite nuclei. Pairing correlations are described by the
pairing part of the finite range Gogny interaction. The new density-dependent
effective interaction DD-ME1 is tested in the analysis of the equations of
state for symmetric and asymmetric nuclear matter, and of ground-state
properties of the Sn and Pb isotopic chains. Results of self-consistent RHB
calculations are compared with experimental data, and with results previously
obtained in the RHB model with non-linear self-interactions, as well as in the
density dependent relativistic hadron field (DDRH) model. Parity-violating
elastic electron scattering on Pb and Sn nuclei is calculated using a
relativistic optical model with inclusion of Coulomb distortion effects, and
the resulting asymmetry parameters are related to the neutron ground-state
density distributions.


title:
Pair term in the Electromagnetic Current within the Front-Form Dynamics:
  Spin-0 Case

abstract:
  The frame and scale dependence of the pair-term contribution to the
electromagnetic form factor of a spin-zero composite system of two-fermions is
studied within the Light Front. The form factor is evaluated from the
plus-component of the current in the Breit frame, using for the first time a
nonconstant, symmetric ansatz for the Bethe-Salpeter amplitude. The frame
dependence is analyzed by allowing a nonvanishing plus component of the
momentum transfer, while the dynamical scale is set by the masses of the
constituents and by mass and size of the composite system. A transverse
momentum distribution, associated with the Bethe-Salpeter amplitude, is
introduced which allows to define strongly and weakly relativistic systems. In
particular, for strongly relativistic systems, the pair term vanishes for the
Drell-Yan condition, while is dominant for momentum transfer along the
light-front direction. For a weakly relativistic system, fitted to the deuteron
scale, the pair term is negligible up to momentum transfers of 1(GeV/c)$^2$. A
comparison with results obtained within the Front-Form Hamiltonian dynamics
with a fixed number of constituents is also presented.


title:
Nuclear Liquid Drop Model with the Surface-Curvature Terms: New
  Perspectives for the Hyperdeformation Studies

abstract:
  Nuclear liquid drop model is revisited and an explicit introduction of the
surface-curvature terms is presented. The corresponding parameters of the
extended classical energy formula are adjusted to the contemporarily known
nuclear binding energies and fission barrier heights. Using 2766 binding
energies of nuclei with $Z\geq 8$ and $N\geq 8$ it is shown that the
performance of the new approach is improved by a factor of about 6, compared to
the previously published liquid drop model results, in terms of both the masses
(new r.m.s. deviation $<\delta M> = 0.698$ MeV) and the fission barriers (new
r.m.s. deviation of the fission barriers of isotopes with $Z> 70$ is $<\delta
V_B> = 0.88$ MeV).
  The role of the curvature terms and their effects on the description of the
experimental quantities are discussed in detail; for comparison the parameters
of the more 'traditional' approaches are re-fitted taking into account the
nuclear masses known today and the performances of several variants of the
model are compared. The isospin dependence in the new description of the
barriers is in a good agreement with the extended Thomas-Fermi approach; it
also demonstrates a good qualitative agreement with the fission life-time
systematics tested on the long chain of Fermium isotopes known experimentally.
  The new approach offers also a very high stability in terms of the
extrapolation from the narrower range of nuclides to a more extended one - a
property of particular interest for the contemporary exotic beam projects: the
corresponding properties are illustrated and discussed.


title:
O(12) limit and complete classification of symmetry schemes in
  proton-neutron interacting boson model

abstract:
  It is shown that the proton-neutron interacting boson model (pnIBM) admits
new symmetry limits with O(12) algebra which break F-spin but preserves the
quantum number M_F. The generators of O(12) are derived and the quantum number
`v' of O(12) for a given boson number N is determined by identifying the
corresponding quasi-spin algebra. The O(12) algebra generates two symmetry
schemes and for both of them, complete classification of the basis states and
typical spectra are given. With the O(12) algebra identified, complete
classification of pnIBM symmetry limits with good M_F is established.


title:
Spectral function and relativistic mean-field description of
  (un)polarized (e,e'p) reactions: a consistent picture

abstract:
  We analyze the unpolarized and polarized electron-induced proton-knockout
reactions on $O^{16}$ in different kinematical settings using two theoretical
approaches. The first one is based on a relativistic mean-field distorted-wave
description of the bound and scattering states of the proton, including a fully
relativistic electromagnetic current operator. The second approach adopts the
same current operator, but describes the proton properties consistently on the
basis of microscopic calculations of the self-energy in $O^{16}$ below the
Fermi energy and final-state damping in nuclear matter above the Fermi energy,
using the same realistic short-range and tensor correlations. Good agreement
with all unpolarized and polarized data is obtained at low and high $Q^2$ by
using the same spectroscopic factors fixed by the low-$Q^2$ analysis,
indicating that a high degree of internal consistency has been reached.


title: Strange particle production at RHIC in the Dual Parton Model

abstract:
  We compute the mid-rapidity densities of pions, kaons, baryons and
antibaryons in $Au$-$Au$ collisions at $\sqrt{s} =$ 130 GeV in the Dual Parton
Model supplemented with final state interaction (comovers interaction). The
ratios $B/n_{part}$ ($\bar{B}/n_{part}$) increase between peripheral ($n_{part}
= 18$) and central ($n_{part} = 350)$ collisions by a factor 2.4 (2.0) for
$\Lambda$'s, 4.8 (4.1) for $\Xi$'s and 16.5 (13.5) for $\Omega$'s. The ratio
$K^-/\pi^-$ increases by a factor 1.3 in the same centrality range. A
comparison with available data is presented.


title:
Relativistic field-theoretical approach to the inverse scattering
  problem

abstract:
  The inverse scattering problem for the relativistic three-dimensional
equation $\Bigl(2E_{\bf p'}-2E_{\bf p}\Bigr)<{\bf p'}|\Psi_{\bf p}>= -\int
V(t)d^3{\bf p''}<{\bf p''}|\Psi_{\bf p}>$ with $E_{\bf p}=\sqrt{m^2+{\bf p}^2}$
and $t=\Bigl(E_{\bf p'}-E_{\bf p''}\Bigr)^2 -\Bigl({\bf p'}-{\bf p''}\Bigr)^2$
is considered. The field-theoretical potential $V(t)$ of this equation is
constructed in the framework of the old perturbation theory. It contains all
contributions of diagrams with intermediate off-mass shell particles. In
particular, this potential reproduces the OBE Bonn model of the $NN$ potential
exactly.For the $\pi N$ scattering it is generated by $\sigma,\rho,
\omega$-meson exchange diagrams. The inverse scattering problem is solved by
reduction of these relativistic equations to the standard Schr\"odinger
equations $\Bigl(\Delta_{\bf r}+{\bf k}^2\Bigr)<{\bf r}|\phi_{\bf p}>= - v({\bf
r})<{\bf r}|\phi_{\bf k}>$ with $E_{\bf p}={\bf k}^2/2m+m$. The relation
between the relativistic potential $V(t)$ and its nonrelativistic
representation $v({\bf r})$ is obtained.


title: Nuclear Many-Body Dynamics constrained by QCD and Chiral Symmetry

abstract:
  We present a novel description of nuclear many-body systems, both for nuclear
matter and finite nuclei, emphasizing the connection with the condensate
structure of the QCD ground state and spontaneous chiral symmetry breaking.
Lorentz scalar and vector mean-fields are introduced in accordance with QCD sum
rules. Nuclear binding arises from pionic fluctuations, using in-medium chiral
perturbation theory up to three-loop order. Ground state properties of $^{16}$O
and $^{40}$Ca are calculated. The built-in QCD constraints reduce the number of
input parameters significantly in comparison with purely phenomenological
relativistic mean-field approaches.


title: Mean-field Based Approaches to Pairing Correlations in Atomic Nuclei

abstract:
  The evolution of the pairing correlations from closed shell to middle shell
nuclei is analyzed with a Finite Range Density Dependent interaction in the Sn
isotopes. As theoretical approaches we use the Hartree-Fock-Bogoliubov, the
Lipkin-Nogami, their particle number projected counterparts and the full
variation after particle number projection method. We find that whereas all
approaches succeed rather well in the description of the total energy they
differ significantly in the pairing correlation content of the wave functions.
The description of the evolution from the weak to the strong pairing regime is
also approach dependent, specially at shell closure.


title: The reaction $\Delta+N\to N+N+\phi$ in ion-ion collisions

abstract:
  We study the threshold $\phi$-meson production in the process $\Delta+N\to
N+N+\phi$, which appears as a possible important mechanism in high energy
nuclei-nuclei collisions. The isotopic invariance of the strong interaction and
the selection rules due to P-parity and total angular momentum result in a
general and model independent parametrization of the spin structure of the
matrix element in terms of three partial amplitudes. In the framework of
one-pion exchange model these amplitudes can be derived in terms of the two
threshold partial amplitudes for the process $\pi+N\to N+\phi$. We predict the
ratio of cross sections for $\phi-$meson production in $pp$- and $\Delta
N$-collisions and the polarization properties of the $\phi$-meson, in
$\Delta+N\to N+N+\phi$, as a function of a single parameter, which
characterizes the relative role of transversal and longitudinal $\phi$-meson
polarizations in the process $\pi+N\to N+\phi$.


title: Statistical Hadronization of Supercooled Quark-Gluon Plasma

abstract:
  The fast simultaneous hadronization and chemical freeze out of supercooled
quark-gluon plasma, created in relativistic heavy ion collisions, leads to the
re-heating of the expanding matter and to the change in a collective flow
profile. We use the assumption of statistical nature of the hadronization
process, and study quantitatively the freeze out in the framework of
hydrodynamical Bjorken model with different quark-gluon plasma equations of
state.


title:
Pseudovector vs. pseudoscalar coupling in one-boson exchange NN
  potentials

abstract:
  We examine the effects of pseudoscalar and pseudovector coupling of the pi
and eta mesons in one-boson exchange models of the NN interaction using two
approaches: time-ordered perturbation theory unitarized with the relativistic
Lippmann-Schwinger equation, and a reduced Bethe-Salpeter equation approach
using the Thompson equation. Contact terms in the one-boson exchange amplitudes
in time-ordered perturbation theory lead naturally to the introduction of
s-channel nucleonic cutoffs for the interaction, which strongly suppresses the
far off-shell behavior of the amplitudes in both approaches. Differences
between the resulting NN predictions of the various models are found to be
small, and particularly so when coupling constants of the other mesons are
readjusted within reasonable limits.


title: Pseudospin symmetry and its approximation in real nuclei

abstract:
  The origin of pseudospin symmetry and its broken in real nuclei are discussed
in the relativistic mean field theory. In the exact pseudospin symmetry, even
the usual intruder orbits have degenerate partners. In real nuclei, pseudospin
symmetry is approximate, and the partners of the usual intruder orbits will
disappear. The difference is mainly due to the pseudo spin-orbit potential and
the transition between them is discussed in details. The contribution of
pseudospin-orbit potential for intruder orbits is quite large, compared with
that for pseudospin doublets. The disappearance of the pseudospin partner for
the intruder orbit can be understood from the properties of its wave function.


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

abstract:
  Basic idea presented in Parts (I)-(III) for the deformed boson scheme is
applied to the case of the su(2)- and su(1,1)-algebras for describing many-body
systems consisting of four kinds of boson operators. A possible form of the
coherent state given by the present authors is generalized and the su(2)_q- and
the su(1,1)_q-algebras are obtained in the form expressed in terms of four
kinds of boson operators. As an illustrative example of the application, the
framework for describing thermal effects observed in two-level shell model
under the pairing correlation is proposed.


title:
Calculation of strongly-coupled rotational bands in terms of the tilted
  axis cranking model

abstract:
  Recently observed strongly-coupled rotational bands associated with the $\nu
[505]{11/2}^-$ quasiparticle state are studied by means of a microscopic tilted
axis cranking (TAC) model. The results of calculation for the routhians and the
$B(M1)/B(E2)$ ratios are investigated in the light of other existing models,
i.e. the strong-coupling model and the conventional cranking model. It is
demonstrated that only the TAC model can successfully reproduce these two
observables at the same time. The reason of the success is clarified by making
connections between these models.


title:
Theoretical predictions for extraction of GEn from semi-inclusive
  electron scattering on polarized 3He based on various nucleon-nucleon
  interactions

abstract:
  The process 3He(e,e'n) with polarized electrons and 3He in the initial state
is theoretically analyzed with the aim to search for sensitivity to the
electric form factor of the neutron, GEn. Faddeev calculations based on five
high precision nucleon-nucleon force models are employed and stability versus
exchange of the nucleon-nucleon forces is demonstrated.


title: Ground state of finite nuclei evaluated from realistic interactions

abstract:
  Ground state properties of finite nuclei ($^{16}$O and $^{40}$Ca) are
evaluated from realistic nucleon-nucleon interactions. The calculations are
based on the Brueckner-Hartree-Fock approximation. Special attention is paid to
the role of the energy spectrum for the particle states, in particular for
those close to the Fermi energy. Additional binding energy is obtained from the
inclusion of the hole-hole scattering term within the framework of the Green
function approach. Results for the energy distribution of the single-particle
strength and the sensitivity to the nucleon-nucleon interaction are
investigated. For that purpose three modern nucleon-nucleon interactions are
employed: the Argonne V18, the charge dependent Bonn potential and a realistic
nucleon-nucleon interaction which is based on chiral perturbation theory and
which has recently been fitted by the Idaho group.


title: RPA puzzle in C(12) weak decay processes

abstract:
  We explain the origin of the difficulties that appear in a straightforward
application of the QRPA in C(12), and we demonstrate that it is imperative to
use the projected QRPA (PQRPA). Satisfactory results, not only for the weak
processes among the ground states of the triad B(12),C(12),N(12), but also for
the inclusive ones are obtained. We sketch as well a new formalism for the
neutrino-nucleus interaction that furnishes very simple final formulae for the
muon capture rate and neutrino induced cross sections.


title:
Monte Carlo integration in Glauber model analysis of reactions of halo
  nuclei

abstract:
  Reaction and elastic differential cross sections are calculated for light
nuclei in the framework of the Glauber theory. The optical phase-shift function
is evaluated by Monte Carlo integration. This enables us to use the most
accurate wave functions and calculate the phase-shift functions without
approximation. Examples of proton nucleus (e.g. p-$^6$He, p-$^6$Li) and
nucleus-nucleus (e.g. $^6$He$-^{12}$C) scatterings illustrate the effectiveness
of the method. This approach gives us a possibility of a more stringent
analysis of the high-energy reactions of halo nuclei.


title: R_{out}/R_{sid} and Opacity at RHIC

abstract:
  One of the most dramatic results from the first RHIC run are the STAR results
for pi+- pi+- interferometry. They showed that the ratio of the so-called
R_{out} and R_{sid} radii seem to decrease below unity for increasing
transverse momentum of the pair (K_T). This was subsequently confirmed by
PHENIX, which also extended the K_T range of the measurements. We consider here
the effects of opacity of the nuclei on this ratio, and find that such a small
value is consistent with surface emission from an opaque source.


title: RPA vs. exact shell-model correlation energies

abstract:
  The random phase approximation (RPA) builds in correlations left out by
mean-field theory. In full 0-hbar-omega shell-model spaces we calculate the
Hartree-Fock + RPA binding energy, and compare it to exact diagonalization. We
find that in general HF+RPA gives a very good approximation to the ``exact''
ground state energy. In those cases where RPA is less satisfactory, however,
there is no obvious correlation with properties of the HF state, such as
deformation or overlap with the exact ground state wavefunction.


title: Nucleus-nucleus collisions at high baryon densities

abstract:
  We study central collision of Pb+Pb at 20, 40, 80 and 160 AGeV within the
UrQMD transport approach and compare rapidity distributions of pi-, K+, K- and
Lambda with the recent measurements from the NA49 Collaboration at 40, 80 and
160 AGeV. It is found that the UrQMD model reasonably describes the data,
however, systematically overpredicts the pi- yield by about 20%, whereas the K+
yield is underestimated by about 15%. The K- yields are in a good agreement
with the experimental data, the Lambda yields are also in a reasonable
correspondence with the data for all energies. We find that hadronic flavour
exchange reactions largely distort the information about the initial
strangeness production mechanism at all energies considered.


title:
Coherent Vector Meson Photoproduction with Nuclear Breakup in
  Relativistic Heavy Ion Collisions

abstract:
  Relativistic heavy ions are copious sources of virtual photons. The large
photon flux gives rise to a substantial photonuclear interaction probability at
impact parameters where no hadronic interactions can occur. Multiple
photonuclear interactions in a single collision are possible. In this letter,
we use mutual Coulomb excitation of both nuclei as a tag for moderate impact
parameter collisions. We calculate the cross section for coherent vector meson
production accompanied by mutual excitation, and show that the median impact
parameter is much smaller than for untagged production. The vector meson
rapidity and transverse momentum distribution are very different from untagged
exclusive vector meson production.


title: Baryon stopping and strange baryon/antibaryon production at SPS energies

abstract:
  The amount of proton stopping in central Pb+Pb collisions from 20-160 AGeV as
well as hyperon and antihyperon rapidity distributions are calculated within
the UrQMD model in comparison to experimental data at 40, 80 and 160 AGeV taken
recently from the NA49 collaboration. Furthermore, the amount of baryon
stopping at 160 AGeV for Pb+Pb collisions is studied as a function of
centrality in comparison to the NA49 data. We find that the strange baryon
yield is reasonably described for central collisions, however, the rapidity
distributions are somewhat more narrow than the data. Moreover, the
experimental antihyperon rapidity distributions at 40, 80 and 160 AGeV are
underestimated by up to factors of 3 - depending on the annihilation cross
section employed - which might be addressed to missing multi-meson fusion
channels in the UrQMD model.


title: Effective interaction for pf-shell nuclei

abstract:
  An effective interaction is derived for use in the full pf basis. Starting
from a realistic G-matrix interaction, 195 two-body matrix elements and 4
single-particle energies are determined by fitting to 699 energy data in the
mass range 47 to 66. The derived interaction successfully describes various
structures of pf-shell nuclei. As examples, systematics of the energies of the
first 2+ states in the Ca, Ti, Cr, Fe, and Ni isotope chains and energy levels
of 56,57,58Ni are presented. The appearance of a new magic number 34 is seen.


title:
Charged multiplicity density and number of participant nucleons in
  relativistic nuclear collisions

abstract:
  The energy and centrality dependences of charged particle pseudorapidity
density in relativistic nuclear collisions were studied using a hadron and
string cascade model, JPCIAE. Both the relativistic $p+\bar p$ experimental
data and the PHOBOS and PHENIX $Au+Au$ data at RHIC energy could be fairly
reproduced within the framework of JPCIAE model and without retuning the model
parameters. The predictions for $Pb+Pb$ collisions at the LHC energy were also
given. We computed the participant nucleon distributions using different
methods. It was found that the number of participant nucleons is not a well
defined variable both experimentally and theoretically. Thus it may be
inappropriate to use the charged particle pseudorapidity density per
participant pair as a function of the number of participant nucleons for
distinguishing various theoretical models. A discussion for the effect of
different definitions in nuclear radius (diffused or sharp) was given.


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

abstract:
  A detailed study of inclusive deep inelastic scattering from mirror A = 3
nuclei at large values of Bjorken-x is presented. The main purpose is to
estimate the theoretical uncertainties on the extraction of F2n from such
measurements. Within the convolution approach we confirm the cancellation of
nuclear effects at the level of ~1 % for x < 0.75 in overall agreement with
previous findings. However, within models in which modifications of the bound
nucleon structure functions are accounted for to describe the EMC effect in
nuclei, we find that the nuclear effects may be canceled at a level of ~ 3 %
only, leading to an accuracy of ~ 12 % in the extraction of F2n / F2p at x ~
0.7 - 0.8. Another consequence of bound nucleon modifications is that the
iteration procedure does not improve the accuracy of the extraction of F2n /
F2p.


title: The superdeformed excited band of Ca-40

abstract:
  The superdeformed band, recently discovered in Ca-40 is analysed in an
spherical shell model context. Two major oscillator shells, sd and pf are
necessary to describe it. The yrast band of the fixed 8p-8h configuration fits
extremely well with the experimental energies and transition rates of the
superdeformed band. The 4p-4h configuration generates a normally deformed band
plus a gamma-band pattern, both are also present in the experimental data.


title:
Microscopic Study of Slablike and Rodlike Nuclei: Quantum Molecular
  Dynamics Approach

abstract:
  Structure of cold dense matter at subnuclear densities is investigated by
quantum molecular dynamics (QMD) simulations. We succeeded in showing that the
phases with slab-like and rod-like nuclei etc. can be formed dynamically from
hot uniform nuclear matter without any assumptions on nuclear shape. We also
observe intermediate phases, which has complicated nuclear shapes. Geometrical
structures of matter are analyzed with Minkowski functionals, and it is found
out that intermediate phases can be characterized as ones with negative Euler
characteristic. Our result suggests the existence of these kinds of phases in
addition to the simple ``pasta'' phases in neutron star crusts.


title:
General Multipole Expansion of Polarization Observables in Deuteron
  Electrodisintegration

abstract:
  Formal expressions are derived for the multipole expansion of the structure
functions of a general polarization observable of exclusive
electrodisintegration of the deuteron using a longitudinally polarized beam
and/or an oriented target. This allows one to exhibit explicitly the angular
dependence of the structure functions by expanding them in terms of the small
rotation matrices $d^j_{m'm}(\theta)$, whose coefficients are given in terms of
the electromagnetic multipole matrix elements. Furthermore, explicit
expressions for the coefficients of the angular distributions of the
differential cross section including multipoles up to $L_{max}=3$ are listed in
tabular form.


title: Estimation of Admixture of Twelve Quark Bag State in He4 Nucleus

abstract:
  The $p{}^4He$ elastic scattering at the energy range from 0.695 to 393 GeV is
analyzed in the framework of the Glauber theory. The Glauber amplitudes were
evaluated using isospin-averaged nucleon-nucleon amplitudes and the ${}^4He$
wave function as a superposition of the Gaussian functions. The values of the
calculated differential cross sections usually exceed the experimental ones. In
order to overcome the discrepancy, it is assumed following to the paper by L.G.
Dakno and N.N. Nikolaev (Nucl. Phys. {\bf A436} (1985) 653) that the ground
state wave function of ${}^4He$ has an admixture of a twelve quark bag.
Neglecting all transition amplitudes, the proton - 12q bag scattering amplitude
was chosen in a simple gaussian form. The inclusion of the 12q bag leads to
decreasing the $p{}^4He$ differential cross section and to a shift of the dip
position to a large values of $t$ what is needed for a successful description
of the experimental data. While fitting the data it is found that the weight of
the 12q bag state in the ground state of the ${}^4He$ nucleus is $\sim 10.5$%,
$\sigma ^{tot}_{p-12q}\sim 34$ mb, and the slope parameter of the $p-12q$ bag
elastic scattering is $\sim$ 23 (GeV/c)$^{-2}$. Inelastic shadowing is not
taken into account at the calculations.


title:
Comparison of space-time evolutions of hot/dense matter in
  $\sqrt{s_{NN}}$=17 and 130 GeV relativistic heavy ion collisions based on a
  hydrodynamical model

abstract:
  Based on a hydrodynamical model, we compare 130 GeV/$A$ Au+Au collisions at
RHIC and 17 GeV/$A$ Pb+Pb collisions at SPS. The model well reproduces the
single-particle distributions of both RHIC and SPS.
  The numerical solution indicates that huge amount of collision energy in RHIC
is mainly used to produce a large extent of hot fluid rather than to make a
high temperature matter; longitudinal extent of the hot fluid in RHIC is much
larger than that of SPS and initial energy density of the fluid is only 5%
higher than the one in SPS. The solution well describes the HBT radii at SPS
energy but shows some deviations from the ones at RHIC.


title:
New features of collective motion of intrinsic degrees of freedom.
  Toward a possible way to classify the intrinsic states

abstract:
  Three exactly solvable Hamiltonians of complex structure are studied in the
framework of a semi-classical approach. The quantized trajectories for
intrinsic coordinates correspond to energies which may be classified in
collective bands. For two of the chosen Hamiltonians the symmetry SU2xSU2 is
the appropriate one to classify the eigenvalues in the laboratory frame.
Connections of results presented here with the molecular spectrum and
Moszkowski model are pointed out. The present approach suggests that the
intrinsic states, which in standard formalisms are heading rotational bands,
are forming themselves "rotational" bands, the rotations being performed in a
fictious boson space.


title:
Axially symmetric Hartree-Fock-Bogoliubov Calculations for Nuclei Near
  the Drip-Lines

abstract:
  Nuclei far from stability are studied by solving the Hartree-Fock-Bogoliubov
(HFB) equations, which describe the self-consistent mean field theory with
pairing interaction. Calculations for even-even nuclei are carried out on
two-dimensional axially symmetric lattice, in coordinate space. The
quasiparticle continuum wavefunctions are considered for energies up to 60 MeV.
Nuclei near the drip lines have a strong coupling between weakly bound states
and the particle continuum. This method gives a proper description of the
ground state properties of such nuclei. High accuracy is achieved by
representing the operators and wavefunctions using the technique of
basis-splines. The detailed representation of the HFB equations in cylindrical
coordinates is discussed. Calculations of observables for nuclei near the
neutron drip line are presented to demonstrate the reliability of the method.


title:
Collective flow and two-pion correlations from a relativistic
  hydrodynamic model with early chemical freeze out

abstract:
  We investigate the effect of early chemical freeze-out on radial flow,
elliptic flow and HBT radii by using a fully three dimensional hydrodynamic
model. When we take account of the early chemical freeze-out, the space-time
evolution of temperature in the hadron phase is considerably different from the
conventional model in which chemical equilibrium is always assumed. As a
result, we find that radial and elliptic flows are suppressed and that the
lifetime and the spatial size of the fluid are reduced. We analyze the p_t
spectrum, the differential elliptic flow, and the HBT radii at the RHIC energy
by using hydrodynamics with chemically non-equilibrium equation of state.


title:
Non-conventional statistical effects in relativistic heavy-ions
  collisions

abstract:
  We show that non-conventional statistical effects (due to the presence of
long range forces, memory effects, correlations and fluctuations) can be very
relevant in the interpretation of the experimental observables in relativistic
heavy-ions collisions. Transverse mass spectrum, transverse momentum
fluctuations and rapidity spectra are analysed in the framework of the
non-extensive statistical mechanics.


title:
Low energy behavior of astrophysical S factor in radiative captures to
  loosely bound final states

abstract:
  The low-energy behavior of the astrophysical S-factor for E1 direct radiative
captures a(p,gamma)b leading to loosely bound final states (b=a+p) is
investigated. We derive a first-order integral representation for S(E) and
focus on the properties around zero energy. We show that it is the competition
between various effects, namely the remnant Coulomb barrier, the initial and
final centrifugal barriers and the binding energy, that defines the behavior of
the S(E->0). Contrary to previous findings, we prove that S(E->0) is not
determined by the pole corresponding to the bound state. The derivative S'(0)
increases with the increase of the centrifugal barrier, while it decreases with
the charge of the target. For l_i=l_f+1 the increase of the binding energy of
the final nucleus increases the derivative S'(0) while for l_i=l_f-1 the
opposite effect is found. We make use of our findings to explain the low energy
behavior of the S-factors related to some notorious capture reactions: 7Be(p,
gamma)8B, 14N(p,gamma)15O, 16O}(p,gamma)17F, 20Ne(p, gamma)21Na and 22Mg(p,
gamma)23Al.


title: Collective modes of asymmetric nuclear matter in Quantum HadroDynamics

abstract:
  We discuss a fully relativistic Landau Fermi liquid theory based on the
Quantum Hadro-Dynamics ($QHD$) effective field picture of Nuclear Matter
  ({\it NM}).
  From the linearized kinetic equations we get the dispersion relations of the
propagating collective modes. We focus our attention on the dynamical effects
of the interplay between scalar and vector channel contributions. A beautiful
``mirror'' structure in the form of the dynamical response in the
isoscalar/isovector degree of freedom is revealed, with a complete parallelism
in the role respectively played by the compressibility and the symmetry energy.
All that strongly supports the introduction of an explicit coupling to the
scalar-isovector channel of the nucleon-nucleon interaction. In particular we
study the influence of this coupling (to a $\delta$-meson-like effective field)
on the collective response of asymmetric nuclear matter ($ANM$). Interesting
contributions are found on the propagation of isovector-like modes at normal
density and on an expected smooth transition to isoscalar-like oscillations at
high baryon density. Important ``chemical'' effects on the neutron-proton
structure of the mode are shown. For dilute $ANM$ we have the isospin
distillation mechanism of the unstable isoscalar-like oscillations, while at
high baryon density we predict an almost pure neutron wave structure of the
propagating sounds.


title: On the cascade approach to the quantum multiscattering problem

abstract:
  The multiscattering problem is studied in the matrix density formalism. We
study how to isolate the quasi-classical degrees of freedom in order to connect
with a cascade approach. The different problems that arise, as well as their
possible solutions, are discussed and exemplified with a pion-nucleus model.


title: Covariant RPA in Effective Hadronic Field Theory

abstract:
  In an effective hadronic theory constructed to describe long-range nuclear
physics, the dynamics of the vacuum can be expanded in terms with zero or a
finite number of derivatives acting on the fields. Thus vacuum dynamics can
always be absorbed in the (infinite number of) counterterm parameters
necessarily present in the effective lagrangian. These finite parameters, which
at present must be fitted to data, encode the empirical vacuum physics as well
as other short-range dynamics into the effective lagrangian; in practice, only
a small number of parameters must be fitted. The strength of the effective
field theory (EFT) framework is that there is no need to make a concrete
picture of the vacuum dynamics, as one does in a renormalizable hadronic
theory. At the one-loop level, the most convenient renormalization scheme
requires explicit sums over long-range (``valence'') nucleon orbitals only,
thus explaining the so-called ``no-sea approximation'' used in successful
covariant mean-field theory (MFT) calculations of static ground states. When
excited states are studied in the random-phase approximation (RPA), the same
EFT scheme dictates the inclusion of both familiar particle-hole pairs and
contributions that mix valence and negative-energy single-particle Dirac wave
functions. The modern EFT strategy therefore justifies and explains the
omission of some explicit contributions from the negative-energy Dirac sea of
nucleons, as was done to maintain conservation laws in earlier pragmatic
calculations of the nuclear linear response.


title: Structure and Dynamics of Charmonium

abstract:
  We apply a confining q\bar{q} potential to charmonium and open charm in order
to model wave functions and to begin studying structure. Results (in momentum
space) provide form-factor input to a four-flavor effective chiral Lagrangian
which models dynamics of charmonium in hot hadronic matter. Estimates are made
for J/\psi dissociation cross sections and rates within a fireball. Our study
attempts to improve on previous comover suppression models since it includes
gauge-invariant form-factor formalism constrained by quark-model phenomenology.


title: On the Penetrating Nature of Electromagnetic Probes

abstract:
  We establish the extent to which photons and dileptons are penetrating probes
of hot hadronic matter by computing mean free paths. Absorption is indeed
negligible for real photons as mean free paths are roughly tenths of
\AAngstr\"oms. However, vector dominance effects, which provide rich structure
in virtual photon mass spectra, introduce nonnegligible reabsorption and
rehadronization resulting in mean free paths of the order of tens of
femtometers. Consequences are illustrated by considering the net dilepton yield
near the rho peak via thermal \pi\pi annihilation from a short-lived hadronic
fireball. Results suggest that disappearance of the rho in heavy-ion collisions
can be due in part to reabsorption/rehadronization rather than solely due to
collective effects.


title: Excluded Volume Effects in the Quark Meson Coupling Model

abstract:
  Excluded volume effects are incorporated in the quark meson coupling model to
take into account in a phenomenological way the hard core repulsion of the
nuclear force. The formalism employed is thermodynamically consistent and does
not violate causality. The effects of the excluded volume on in-medium nucleon
properties and the nuclear matter equation of state are investigated as a
function of the size of the hard core. It is found that in-medium nucleon
properties are not altered significantly by the excluded volume, even for large
hard core radii, and the equation of state becomes stiffer as the size of the
hard core increases.


title:
Effective Lagrangian approach to the omega meson photoproduction near
  threshold

abstract:
  We apply the effective Lagrangian approach to investigate the role of the
nucleon resonances in $\omega$ meson photoproduction at energies near the
threshold. The resonant amplitudes are calculated from effective Lagrangians
with the gamma NN* and omega NN* coupling constants fixed by the empirical
helicity amplitudes and the vector meson dominance model. The contributions
from the nucleon resonances are found to be significant in changing the
differential cross sections in a wide interval of t and various spin
observables.


title:
Comparison of hadronic rescattering calculations of elliptic flow and
  HBT with measurements from RHIC

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


title: Density dependence of the s-wave repulsion in pionic atoms

abstract:
  Several mechanisms of density dependence of the s-wave repulsion in pionic
atoms, beyond the conventional model, are tested by parameter fits to a large
(106 points) set of data from $^{16}$O to $^{238}$U, including `deeply bound'
states in $^{205}$Pb. Special attention is paid to the proper choice of nuclear
density distributions. A density-dependent isovector scattering amplitude
suggested recently by Weise to result from a density dependence of the pion
decay constant is introduced and found to account for most of the so-called
anomalous repulsion. The presence of such an effect might indicate partial
chiral symmetry restoration in dense matter. The anomalous repulsion is fully
accounted for when an additional relativistic impulse approximation term is
included in the potential.


title:
Meson exchange currents in a relativistic model for electromagnetic one
  nucleon emission

abstract:
  We analyze the role of meson exchange currents (MEC) in photon- and
electron-induced one nucleon emission reactions in a fully relativistic model.
The relativistic mean field theory is used for the bound state and the Pauli
reduction for the scattering state. Direct 1-body and exchange 2-body terms in
the nuclear current are considered. Results for the 12C(gamma,p) and
16O(gamma,p) differential cross sections and photon asymmetries are displayed
in an energy range between 60 and 196 MeV. The 2-body seagull current affects
the cross section less than in nonrelativistic analyses. In the case of the
16O(gamma,n) differential cross section MEC effects are large but not
sufficient to reproduce the data. MEC have a small effect on (e,e'p)
calculations.


title: Partonic Effects in Heavy Ion Collisions at RHIC

abstract:
  Effects of partonic interactions in heavy ion collisions at RHIC are studied
in a multiphase transport model (AMPT) that includes both initial partonic and
final hadronic interactions.It is found that a large parton scattering cross
section is needed to understand the measured elliptic flow of pions and
two-pion correlation function.


title:
Evaluation of QCD sum rules for light vector mesons at finite density
  and temperature

abstract:
  QCD sum rules are evaluated at finite nucleon densities and temperatures to
determine the change of mass parameters for the lightest vector mesons $\rho$,
$\omega$ and $\phi$ in a strongly interacting medium. For conditions relevant
for the starting experiments at HADES we find that the in-medium mass shifts of
the $\rho$ and $\omega$ mesons are governed, within the Borel QCD sum rule
approach, by the density and temperature dependence of the four-quark
condensate. In particular, the variation of the strength of the density
dependence of the four-quark condensate reflects directly the decreasing mass
of the $\rho$ meson and can lead to a change of the sign of the $\omega$ meson
mass shift as a function of the density. In contrast, the in-medium mass of the
$\phi$ meson is directly related to the chiral strange quark condensate which
seems correspondingly accessible.


title: Introduction to Effective Field Theories in QCD

abstract:
  We present a simple introduction to the techniques of effective field theory
(EFT) and their application to QCD. For problems with more than one energy
scale, the EFT approach is a useful alternative to more traditional
model-building strategies. The most relevant such problem for this discussion
is that of making contact between QCD and the hadronic phase of matter. As a
simple example, an EFT calculation of the bound states of hydrogen within QED
is sketched. A more significant demonstration of the power of EFTs, the
construction of the chiral Lagrangian and chiral perturbation theory, is also
included. The results provide us with the road map to a complete QCD-based
theory of nuclear matter at nonzero temperatures and densities, a vital
component to a quantitative understanding of the phase transition from hadron
gas to quark-gluon plasma.


title:
Nuclear Tetrahedral Symmetry: Possibly Present Throughout the Periodic
  Table

abstract:
  More than half a century after the fundamental, spherical shell structure in
nuclei has been established, theoretical predictions indicate that the
shell-gaps comparable or even stronger than those at spherical shapes may
exist. Group-theoretical analysis supported by realistic mean-field
calculations indicate that the corresponding nuclei are characterized by the
$T_d^D$ ('double-tetrahedral') group of symmetry, exact or approximate. The
corresponding strong shell-gap structure is markedly enhanced by the existence
of the 4-dimensional irreducible representations of the group in question and
consequently it can be seen as a geometrical effect that does not depend on a
particular realization of the mean-field. Possibilities of discovering the
corresponding symmetry in experiment are discussed.


title: Absence of anomalous stopping in heavy ion collisions

abstract:
  We show that the baryon stopping observed in heavy ion collisions both at
CERN-SPS and at RHIC can be derived from the one observed in proton-proton
collisions. No increase in the size of the baryon junction component is
required between small size $(pp)$ and large size (AA) systems.


title: Probing Proton Strangeness with Time-Like Virtual Compton Scattering

abstract:
  We document that p(gamma,e+e-)p measurements will yield new, important
information about the off-shell time-like nucleon form factors, especially in
the phi meson region (q^2 = M^2_{phi}) governing the phi N couplings
g^{V,T}_{\phi N N}. Calculations for p(gamma,e+e-)p, utilizing vector meson
dominance, predict measurable phi enhancements at high |t| compared to the
expected phi background production from pi, eta and Pomeron exchange. The phi
form factor contribution generates a novel experimental signature for OZI
violation and the proton strangeness content. The phi N couplings are
determined independently from a combined analysis of the neutron electric form
factor and recent high |t| phi photoproduction. The pi, eta and Pomeron
transition form factors are also predicted and the observed pi and eta
transition moments are reproduced.


title:
Triton binding energy calculated from the SU_6 quark-model
  nucleon-nucleon interaction

abstract:
  Properties of the three-nucleon bound state are examined in the Faddeev
formalism, in which the quark-model nucleon-nucleon interaction is explicitly
incorporated to calculate the off-shell T-matrix. The most recent version,
fss2, of the Kyoto-Niigata quark-model potential yields the ground-state energy
^3H=-8.514 MeV in the 34 channel calculation, when the np interaction is used
for the nucleon-nucleon interaction. The charge root mean square radii of the
^3H and ^3He are 1.72 fm and 1.90 fm, respectively, including the finite size
correction of the nucleons. These values are the closest to the experiments
among many results obtained by detailed Faddeev calculations employing modern
realistic nucleon-nucleon interaction models.


title: Effective Field Theory for Halo Nuclei: Shallow p-Wave States

abstract:
  Halo nuclei are a promising new arena for studies based on effective field
theory (EFT). We develop an EFT for shallow p-wave states and discuss the
application to elastic n-alpha scattering. In contrast to the s-wave case, both
the scattering length and effective range enter at leading order. We also
discuss the prospects of using EFT in the description of other halos, such as
the three-body halo nucleus 6He.


title:
Nuclear modification of heavy quark fragmentation function and J/psi
  production in ultrarelativistic heavy ion collisions

abstract:
  In ultrarelativistic heavy ion collisions, charm quark fragmentation is
modified due to the melting of strings inside the high density partonic matter.
D mesons produced in hadronization can further produce J/psi particles. Using a
multiphase transport model, we investigate the effect on the rapidity
distribution of the produced J/psi particles with two different charm quark
fragmentation functions. It is shown that the J/psi rapidity distribution is
sensitive to the nuclear modification of charm quark fragmentation and thus is
a good indicator of the onset of string melting and the production of
deconfined partonic matter.


title:
Form-factor dependence of the J/psi dissociation cross sections in meson
  exchange model

abstract:
  The $J/\psi$ dissociation by $\pi$ and $\rho$ mesons is examined in meson
exchange model and compared to the quark interchange model. We found that the
main difference between the predictions of the two models could be resolved by
the form factors and the contact interactions in meson exchange model
calculations. By adopting covariant form factors and adjusting the four-point
couplings, we found that the meson exchange model could give similar
predictions with the quark interchange models not only for the magnitudes but
also for the energy dependence of the low-energy dissociation cross sections of
the $J/\psi$ by $\pi$ and $\rho$ mesons. Our finding suggests a way to
understand one of the discrepancies among the existing model predictions on the
$J/\psi$ dissociation cross sections by light hadrons.


title:
Penetration of a high energy QQbar bound state through SU(N) color
  background

abstract:
  Attenuation of the singlet quark--anti-quark bound state passing through a
random external SU(N) color field at high energy is studied within the eikonal
framework as a model for the absorption of a quarkonium by nuclear target. For
a thick target of length L the penetration probability is suppressed
non-exponentially and behaves asymptotically $\propto 1/LN^2$ with 1/N^2
indicating the equi-partitioning in the color space. An approximate rational
expression for the penetration of the small Gaussian bound state is found which
allows the explicit L and N dependences, and shows the attenuation is in the
powers of L although the approach to the asymptote is rather slow.


title: Analysis of Pion Photoproduction Data

abstract:
  A partial-wave analysis of single-pion photoproduction data has been
completed. This study extends from threshold to 2 GeV in the laboratory photon
energy, focusing mainly on the influence of new measurements and
model-dependence in the choice of parameterization employed above the two-pion
threshold. Results are used to evaluate sum rules and estimate resonance
photo-decay amplitudes. These are compared to values obtained in the MAID
analysis.


title:
Combinatorial Level Densities from a Microscopic Relativistic Structure
  Model

abstract:
  A new model for calculating nuclear level densities is investigated. The
single-nucleon spectra are calculated in a relativistic mean-field model with
energy-dependent effective mass, which yields a realistic density of
single-particle states at the Fermi energy. These microscopic single-nucleon
states are used in a fast combinatorial algorithm for calculating the
non-collective excitations of nuclei. The method, when applied to magic and
semi-magic nuclei, such as $^{60}$Ni, $^{114}$Sn and $^{208}$Pb, reproduces the
cumulative number of experimental states at low excitation energy, as well as
the s-wave neutron resonance spacing at the neutron binding energy.
Experimental level densities above 10 MeV are reproduced by multiplying the
non-collective level densities by a simple vibrational enhancement factor.
Problems to be solved in the extension to open-shell nuclei are discussed


title:
Is the existence of a softest point in the directed flow excitation
  function an unambiguous signal for the creation of a quark-gluon plasma?

abstract:
  The excitation function of the in-plane directed flow of nucleons is studied
within a non-equilibrium transport approach. It is demonstrated that a local
minimum in the excitation function of the directed flow develops, which is not
related to a transition into a quark-gluon plasma (QGP) phase. It is a
consequence of the dynamical softening of the underlying equation of state, due
to the onset of resonance matter and particle production. Thus, the
interpretation of this minimum as a 'smoking gun' signature for the creation of
a QGP is premature.


title: A schematic model for QCD at finite temperature

abstract:
  The simplest version of a class of toy models for QCD is presented. It is a
Lipkin-type model, for the quark-antiquark sector, and, for the gluon sector,
gluon pairs with spin zero are treated as elementary bosons. The model
restricts to mesons with spin zero and to few baryonic states. The
corresponding energy spectrum is discussed. We show that ground state
correlations are essential to describe physical properties of the spectrum at
low energies. Phase transitions are described in an effective manner, by using
coherent states. The appearance of a Goldstone boson for large values of the
interaction strength is discussed, as related to a collective state. The
formalism is extended to consider finite temperatures. The partition function
is calculated, in an approximate way, showing the convenience of the use of
coherent states. The energy density, heat capacity and transitions from the
hadronic phase to the quark-gluon plasma are calculated.


title: Self-consistent antikaon dynamics in isospin-asymmetric nuclear medium

abstract:
  We investigate properties of antikaons and hyperon resonances in
isospin-asymmetric nuclear medium, using a self-consistent, covariant scheme
based on vacuum antikaon-nucleon scattering amplitude.


title: Fully-Renormalized QRPA fulfills Ikeda sum rule exactly

abstract:
  The renormalized quasiparticle-RPA is reformulated for even-even nuclei using
restrictions imposed by the commutativity of the phonon creation operator with
the total particle number operator. This new version, Fully-Renormalized QRPA
(FR-QRPA), is free from the spurious low-energy solutions. Analytical proof is
given that the Ikeda sum rule is fullfiled within the FR-QRPA.


title: How random are random nuclei? Shapes, triangles and kites

abstract:
  We study the origin of the regular features obtained in numerical studies of
the IBM with random interactions, in particular the dominance of L=0 ground
states and the occurrence of vibrational and rotational band structures. It is
shown that the geometric shapes associated with IBM Hamiltonians play a crucial
role in understanding these regular properties. Different regions of the
parameter space are associated with definite geometric shapes, such as
spherical and deformed shapes and a condensate of quadrupole bosons.


title: Beyond mean-field description of the low-lying spectrum of 16O

abstract:
  Starting from constrained Skyrme-mean-field calculations, the low-energy
excitation spectrum of 16O is calculated by configuration mixing of
particle-number and angular-momentum projected mean-field states in the
framework of the Generator Coordinate Method. Without any adjustable
parameters, this approach gives a very good description of those states and
their transition moments that can be described with our restriction to axially
and reflection-symmetric shapes. The structure of low-lying 0+ states is
analyzed in terms of self-consistent 0p-0h, 2p-2h, and 4p-4h Hartree-Fock
states.


title: Phi meson mass and decay width in nuclear matter

abstract:
  The $\phi$ meson spectrum, which in vacuum is dominated by its coupling to
the $\bar{K} K$ system, is modified in nuclear matter. Following a model based
on chiral SU(3) dynamics we calculate the $\phi$ meson selfenergy in nuclear
matter considering the $K$ and $\bar{K}$ in-medium properties. For the latter
we use the results of previous calculations which account for $S-$ and $P-$wave
kaon-nucleon interactions based on the lowest order meson-baryon chiral
effective Lagrangian, and this leads to a dressing of the kaon propagators in
the medium. In addition, a set of vertex corrections is evaluated to fulfill
gauge invariance, which involves contact couplings of the $\phi$ meson to
$S-$wave and $P-$wave kaon-baryon vertices. Within this scheme the mass shift
and decay width of the $\phi$ meson in nuclear matter are studied.


title: Unitarity and the Bethe-Salpeter Equation

abstract:
  We investigate the relation between different three-dimensional reductions of
the Bethe-Salpeter equation and the analytic structure of the resultant
amplitudes in the energy plane. This correlation is studied for both the
$\phi^2\sigma$ interaction Lagrangian and the $\pi N$ system with $s$-, $u$-,
and $t$-channel pole diagrams as driving terms. We observe that the equal-time
equation, which includes some of the three-body unitarity cuts, gives the best
agreement with the Bethe-Salpeter result. This is followed by other 3-D
approximations that have less of the analytic structure.


title:
Extended 9Li+n+n three-body model of 11Li with the pairing correlation
  in 9Li

abstract:
  We discuss the binding mechanism of 11Li based on an extended three-body
model of Li+n+n. In the model, we take into account the pairing correlation of
p-shell neutrons in 9Li, in addition to that of valence neutrons outside the
9Li nucleus, and solve the coupled-channel two- and three-body problems of 10Li
and 11Li, respectively. The results show that degrees of freedom of the pairing
correlation in 9Li play an important role in the structure of 10Li and 11Li. In
10Li, the pairing correlation in 9Li produces a so-called pairing-blocking
effect due to the presence of valence neutron, which degenerates s- and p-wave
neutron orbits energetically. In 11Li, on the other hand, the pairing-blocking
effect is surpassed by the core-n interaction due to two degrees of freedom of
two valence neutrons surrounding 9Li, and as a result, the ground state is
dominated by the p-shell closed configuration and does not show a spatial
extension with a large r.m.s. radius. These results indicate that the pairing
correlation is realized differently in odd- and even-neutron systems of 10Li
and 11Li. We further improve the tail part of the 9Li-n interaction, which
works well to reproduce the observed large r.m.s. radius in 11Li.


title:
Energy dependence of string fragmentation function and $\phi$ meson
  production

abstract:
  The $\phi$ meson productions in $Au+Au$ and/or $Pb+Pb$ collisions at AGS,
SPS, RHIC, and LHC energies have been studied systematically with a hadron and
string cascade model LUCIAE. After considering the energy dependence of the
model parameter $\alpha$ in string fragmentation function and adjusting it to
the experimental data of charged multiplicity to a certain extent, the model
predictions for $\phi$ meson yield, rapidity, and/or transverse mass
distributions are compatible with the experimental data at AGS, SPS and RHIC
energies. A calculation for $Pb+Pb$ collisions at LHC energy is given as well.
The obtained fractional variable in string fragmentation function shows a
saturation in energy dependence. It is discussed that the saturation of
fractional variable in string fragmentation function might be a qualitative
representation of the energy dependence of nuclear transparency.


title: Dipole excited states in $^{11}$Li with complex scaling

abstract:
  The 1$^-$ excitations of the three--body halo nucleus $^{11}$Li are
investigated. We use adiabatic hyperspherical expansion and solve the Faddeev
equations in coordinate space. The method of complex scaling is used to compute
the resonance states. The Pauli forbidden states occupied by core neutrons are
excluded by constructing corresponding complex scaled phase equivalent two-body
potentials. We use a recently derived neutron--core interaction consistent with
known structure and reaction properties of $^{10}$Li and $^{11}$Li. The
computed dipole excited states with $J^\pi=1/2^+$, $J^\pi=3/2^+$, and
$J^\pi=5/2^+$ have energies ranging from 0.6 MeV to 1.0 MeV and widths between
0.15 MeV and 0.65 MeV. We investigate the dependence of the complex energies of
these states on the $^{10}$Li spectrum. The finite spin 3/2 of the core and the
resulting core-neutron spin-spin interaction are important. The connection with
Coulomb dissociation experiments is discussed and a need for better
measurements is pointed out.


title:
Longitudinal gluons and Nambu-Goldstone bosons in a two-flavor color
  superconductor

abstract:
  In a two-flavor color superconductor, the SU(3)_c gauge symmetry is
spontaneously broken by diquark condensation. The Nambu-Goldstone excitations
of the diquark condensate mix with the gluons associated with the broken
generators of the original gauge group. It is shown how one can decouple these
modes with a particular choice of 't Hooft gauge. We then explicitly compute
the spectral density for transverse and longitudinal gluons of adjoint color 8.
The Nambu-Goldstone excitations give rise to a singularity in the real part of
the longitudinal gluon self-energy. This leads to a vanishing gluon spectral
density for energies and momenta located on the dispersion branch of the
Nambu-Goldstone excitations.


title: Solar-neutrino reactions on deuteron in effective field theory

abstract:
  The cross sections for low-energy neutrino-deuteron reactions are calculated
within heavy-baryon chiral perturbation theory employing cut-off regularization
scheme. The transition operators are derived up to
next-to-next-to-next-to-leading order in the Weinberg counting rules, while the
nuclear matrix elements are evaluated using the wave functions generated by a
high-quality phenomenological NN potential. With the adoption of the
axial-current-four-nucleon coupling constant fixed from the tritium beta decay
data, our calculation is free from unknown low-energy constants. Our results
exhibit a high degree of stability against different choices of the cutoff
parameter, a feature which indicates that, apart from radiative corrections,
the uncertainties in the calculated cross sections are less than 1 %.


title: Path-integral hadronization for the nucleon and its interactions

abstract:
  Nucleon structure and the origin and nature of the nuclear force are
investigated in the context of a QCD-based effective field theory and the
path-integral method of hadronization. We start from a microscopic model of
quarks and diquarks where the gluons have been integrated out. In particular,
we use the chiral Nambu-Jona-Lasinio model to describe quark dynamics and
assume that the nucleon can be conceived as a quark-diquark relativistic bound
state. The hadronization method is then used to rewrite the problem in terms of
the physical meson and nucleon degrees of freedom. Next, by employing a loop
and derivative expansion of the resulting quark/diquark determinants, we arrive
at an effective chiral meson-nucleon Lagrangian. Nucleon properties such as
mass, coupling constants, electromagnetic radii, anomalous magnetic moments,
and form factors are derived using a theory of at most two free parameters.


title:
Quasifree processes from nuclei: Meson photoproduction and electron
  scattering

abstract:
  We have developed a relativistic formalism for studying quasi-free processes
from nuclei. The formalism can be applied with ease to a variety of processes
and renders transparent analytical expressions for all observables. We have
applied it to kaon photoproduction and to electron scattering. For the case of
the kaon, we compute the recoil polarization of the lambda-hyperon and the
photon asymmetry. Our results indicate that polarization observables are
insensitive to relativistic, nuclear target, and distortion effects. Yet, they
are sensitive to the reactive content, making them ideal tools for the study of
modifications to the elementary amplitude -- such as in the production,
propagation, and decay of nucleon resonances -- in the nuclear medium. For the
case of the electron, we have calculated the spectral function of He-4. An
observable is identified for the clean and model-independent extraction of the
spectral function. Our calculations provide baseline predictions for the
recently measured, but not yet fully analyzed, momentum distribution of He-4 by
the A1-collaboration from Mainz. Our approach predicts momentum distributions
for He-4 that rival some of the best non-relativistic calculations to date.


title: Quantum effects with an X-ray free electron laser

abstract:
  A quantum kinetic equation coupled with Maxwell's equation is used to
estimate the laser power required at an XFEL facility to expose intrinsically
quantum effects in the process of QED vacuum decay via spontaneous pair
production. A 9 TW-peak XFEL laser with photon energy 8.3 keV could be
sufficient to initiate particle accumulation and the consequent formation of a
plasma of spontaneously produced pairs. The evolution of the particle number in
the plasma will exhibit non-Markovian aspects of the strong-field pair
production process and the plasma's internal currents will generate an electric
field whose interference with that of the laser leads to plasma oscillations.


title: Strangeness Enhancement in the Parton Model

abstract:
  Strangeness enhancement in heavy-ion collisions is studied at the parton
level by examining the partition of the new sea quarks generated by gluon
conversion into the strange and non-strange sectors. The CTEQ parton
distribution functions are used as a baseline for the quiescent sea before
gluon conversion. By quark counting simple constraints are placed on the hadron
yields in different channels. The experimental values of particle ratios are
fitted to determine the strangeness enhancement factor. A quantitative measure
of Pauli blocking is determined. Energy dependence between SPS and RHIC
energies is well described. No thermal equilibrium or statistical model is
assumed.


title: Perturbative QCD Results on Pion Production in pp, pA and AA Collisions

abstract:
  We summarize new pQCD results on pion production in proton-proton (pp),
proton-nucleus (pA) and nucleus-nucleus (AA) collisions. Our calculation
introduces intrinsic parton transverse momentum (k_T) and is performed
effectively at next-to-leading order (NLO), applying a K factor extracted for
jet events. Two different factorization scales, Q=p_{T,jet}/2 and p_{T,jet} are
used. Experimental data in pA collisions imply a preference for the latter
choice at NLO level. We display our results at CERN SPS for AA collisions.


title: Model Predictions for the Phenomenology of Isoscalar Heavy Baryons

abstract:
  We study certain physical observables of isoscalar heavy baryons using
potential models based on hadronic degrees of freedom. The goal is to compare
these results with those from an effective theory obtained in a combined heavy
quark and large $N_{c}$ expansion and thereby test the convergence of the
effective theory. We study the excitation energy of $\Lambda_{b}$ and
semileptonic decay form factors. The models tend to confirm the usefulness of
the effective theory for most observables.


title: Study of Giant Pairing Vibrations with neutron-rich nuclei

abstract:
  We investigate the possible signature of the presence of giant pairing states
at excitation energy of about 10 MeV via two-particle transfer reactions
induced by neutron-rich weakly-bound projectiles. Performing particle-particle
RPA calculations on $^{208}$Pb and BCS+RPA calculations on $^{116}$Sn, we
obtain the pairing strength distribution for two particles addition and removal
modes. Estimates of two-particle transfer cross sections can be obtained in the
framework of the 'macroscopic model'. The weak-binding nature of the projectile
kinematically favours transitions to high-lying states. In the case of $(~^6He,
\~^4He)$ reaction we predict a population of the Giant Pairing Vibration with
cross sections of the order of a millibarn, dominating over the mismatched
transition to the ground state.


title: The hadron-quark phase transition in dense matter and neutron stars

abstract:
  We study the hadron-quark phase transition in the interior of neutron stars
(NS's). We calculate the equation of state (EOS) of hadronic matter using the
Brueckner-Bethe-Goldstone formalism with realistic two-body and three-body
forces, as well as a relativistic mean field model. For quark matter we employ
the MIT bag model constraining the bag constant by using the indications coming
from the recent experimental results obtained at the CERN SPS on the formation
of a quark-gluon plasma. We find necessary to introduce a density dependent bag
parameter, and the corresponding consistent thermodynamical formalism. We
calculate the structure of NS interiors with the EOS comprising both phases,
and we find that the NS maximum masses fall in a relatively narrow interval,
$1.4 M_\odot \leq M_{\rm max} \leq 1.7 M_\odot$. The precise value of the
maximum mass turns out to be only weakly correlated with the value of the
energy density at the assumed transition point in nearly symmetric nuclear
matter.


title: Systematic Study of Elliptic Flow at RHIC Energy

abstract:
  We study the elliptic flow systematically from SIS to RHIC energies in a
realistic dynamical cascade model. We compile our results with the recent data
from STAR and PHOBOS experiments on elliptic flow of charged particles in Au +
Au collisions at RHIC energy. From the analysis of elliptic flow as a function
of different dynamical variables such as transverse momenta, pseudorapidity and
centrality at RHIC energy, we found a good fitting with data at 1.5 times a
scaling factor to our simulation model, which characterizes that the model is
required to have extra pressure generated from the subsequent parton
scatterings. In energy dependence of elliptic flow, we observe a re-hardening
nature at RHIC energies, which may probably signal the possible formation of
quark-gluon plasma.


title: How the HBT-Puzzle at RHIC might dissipate

abstract:
  I compute the first-order corrections to two-particle Bose-Einstein
correlations due to deviations from equilibrium. Based on that result I argue
that for nearly perfect fluids, the HBT radii ``freeze out'' much later than
the single-inclusive distribution. Therefore, to prevent a big longitudinal
homogeneity length, the QGP presumably should hadronize not into a nearly
perfect fluid of hadrons but rather into a very dissipative one. This could be
achieved by a hadronization phase transition away from equilibrium.


title:
Shell-Model Calculations for_{\Lambda}^{16}O and_{\Lambda}^{17}O Using
  Microscopic Effective Interactions with \Sigma Degrees of Freedom

abstract:
  Shell-model calculations in a large model space are performed for
_{\Lambda}^{16}O and_{\Lambda}^{17}O. Effective interactions with degrees of
freedom of \Sigma in addition to \Lambda and nucleons are derived from
hyperon-nucleon and nucleon-nucleon interactions within the framework of the
unitary-model-operator approach. Effects of the \Sigma degrees of freedom and
the parity-mixing intershell coupling on the \Lambda hypernuclear structure are
investigated, employing the Nijmegen NSC97a-f and NSC89 hyperon-nucleon
potentials.


title:
Momentum distribution of relativistic nuclei with Hartree-Fock mesonic
  correlations

abstract:
  The impact of Hartree-Fock correlations on the nuclear momentum distribution
is studied in a fully relativistic one boson exchange model. Hartree-Fock
equations are exactly solved to first order in the coupling constants. The
renormalization of the Dirac spinors in the medium is shown to affect the
momentum distribution, as opposed to what happens in the non-relativistic case.
The unitarity of the model is shown to be preserved by the present
renormalization procedure.


title: Violation of energy-per-hadron scaling in a resonance matter

abstract:
  Yields of hadrons, their average masses and energies per hadron at the stage
of chemical freeze-out in (ultra)relativistic heavy-ion collisions are analyzed
within the statistical model. The violation of the scaling <E>/<N> = 1 GeV
observed in Au+Au collisions at $\sqrt{s}$ = 130 AGeV is linked to the
formation of resonance-rich matter with a considerable fraction of baryons and
antibaryons. The rise of the energy-per-hadron ratio in baryon-dominated matter
is discussed. A violation of the scaling condition is predicted for a very
central zone of heavy-ion collisions at energies around 40 AGeV.


title: Is the Equation of State of strongly interacting matter observable ?

abstract:
  I review the available empirical information on the equation of state of cold
strongly interacting matter, as well as the prospects for obtaining new
insights from the experimental study of gravitational waves emitted by neutron
stars.


title:
The Pairing interaction in nuclei: comparison between exact and
  approximate treatments

abstract:
  As a model for a deformed nucleus the many level pairing model (picket fence
model with ~100 levels) is considered in four approximations and compared to
the exact solution given by Richardson long time ago. It is found that, as
usual, the number projected BCS method improves over standard BCS but that it
is much less accurate than the more sophisticated many-body-approaches which
are Coupled Cluster Theory (CCT) in its SUB2 version or Self-Consistent Random
Phase Approximation (SCRPA).