title: Effective Vector Meson Masses in a Cutoff Field Theory

abstract:
  Based on quantum hadrodynamics with a finite cutoff, the effective masses of
vector mesons(\omega, \rho) in nuclear medium are calculated. We use a
low-energy effective Lagrangian which is obtained by integrating high-energy
quantum fluctuations. Although we use an artificial cutoff, the
cutoff-dependence can be removed order by order. It is shown that there is a
strong correlation between the effective \omega -meson mass and the effective
nucleon mass at the normal density. It is also found that the effective
\rho-meson mass m_\rho^* decreases as density increases. The rate of the
decrease becomes smaller at high density. As a result, at the normal density,
the m^*_\rho/m_\rho is 0.85 \sim 0.95.


title: Parity Violation in gamma proton Compton Scattering

abstract:
  A measurement of parity-violating spin-dependent gamma proton Compton
scattering will provide a theoretically clean determination of the
parity-violating pion-nucleon coupling constant $h_{\pi NN}^{(1)}$. We
calculate the leading parity-violating amplitude arising from one-loop pion
graphs in chiral perturbation theory. An asymmetry of ~5 10^{-8} is estimated
for Compton scattering of 100 MeV photons.


title: Spin Alignments in Heavy-ion Resonances

abstract:
  Recent particle-particle-$\gamma$ coincident measurements on a $^{28}\rm
Si+{}^{28}Si$ resonance have suggested ''vanishing spin alignments''. New
analyses for spin alignments by using a molecular model are reported. Different
aspects between di-nuclear systems with prolate deformed nuclei and those with
oblate deformed nuclei are clarified.


title: On the Collisional Damping of Giant Dipole Resonance

abstract:
  Collisional damping widths of giant dipole excitations are calculated in
Thomas-Fermi approximation by employing the microscopic in-medium
cross-sections of Li and Machleidt and the phenomenological Gogny force. The
results obtained in both calculations compare well, but account for about
25-35% of the observed widths in $^{120}Sn$ and $^{208}Pb$ at finite
temperatures.


title:
Inclusive Scattering of Polarized Electrons on Polarized 3He Effects of
  Final State Interaction and the Magnetic Form Factor of the Neutron

abstract:
  Effects of final state interaction on asymmetries in inclusive scattering of
polarized electrons on polarized 3He are investigated using consistent 3He
bound state wave function and 3N continuum scattering states. Significant
effects are found, which influence the extraction of the magnetic neutron form
factor from A_T'. The enhancement found experimentally for A_TL' near the 3N
breakup threshold, which could not be explained in calculations carried through
in plane wave impulse approximation up to now, occurs now also in theory if the
full final state interaction is included.


title: Role of nucleon resonance excitation in $\phi$ meson photoproduction

abstract:
  The resonance effects are investigated in the $\phi$ meson photoproduction
near threshold through a quark model approach with an effective Lagrangian. The
diffractive contribution is consistently estimated by the {\it t}-channel
Pomeron exchange. Another non-diffractive process, {\it t}-channel $\pi^0$
exchange is also included. The numerical result shows that the Pomeron exchange
plays dominant role in the $\phi$ meson photoproduction, while the cross
sections of the non-diffractive processes, i.e. {\it s}- and {\it u}-channel
excitations, and {\it t}-channel $\pi^0$ exchange, are quite small. In the
polarization observables, we find that large asymmetries are produced in the
backward direction by the interferences from the {\it s}- and {\it u}-channel
resonances, while in the forward direction, only very small asymmetries are
generated. Meanwhile, we find that the effects from the $\pi^0$ exchange are
generally negligible.


title:
Nucleonic resonance excitations and "missing resonances" in the $\omega$
  meson photoproduction

abstract:
  In this work, an improved quark model approach to the $\omega$ meson
photoproduction with an effective Lagrangian is reported. The {\it t}-channel
{\it natural} parity exchange is consistently taken into account through the
Pomeron exchange, while the {\it unnatural} parity exchange is described by the
$\pi^0$ exchange. It shows that with very limited number of parameters, all the
available experimental data in the low energy regime can be consistently
accounted for in this framework. Effects from the intermediate nucleonic
resonances are investigated in several polarization observables. The
sensitivities of these observables to the resonance effects are probably the
best way for identifying those so-called "missing resonances" in the baryon
spectrum.


title: Electromagnetic response functions of few-nucleon systems

abstract:
  Inclusive electromagnetic reactions in few-nucleon systems are studied basing
on accurate three- and four-body calculations. The longitudinal 4He(e,e')
response function obtained at q\le 600 MeV/c completely agrees with experiment.
The exact 4He spectral function obtained in a semirealistic potential model is
presented, and the accuracy of the quasielastic response calculated with its
help is assessed, as well as the accuracy of some simpler approximations for
the response. The photodisintegration cross section of 3He obtained with the
realistic AV14 NN force plus UrbanaVIII NNN force agrees with experiment. It is
shown that this cross section is very sensitive to underlying nuclear dynamics
in the E_\gamma\simeq 70-100 MeV region. In particular, the NNN nuclear force
clearly manifests itself in this region.


title:
Droplet formation in cold asymmetric nuclear matter in the
  quark-meson-coupling model

abstract:
  The quark-meson-coupling model is used to study droplet formation from the
liquid-gas phase transition in cold asymmetric nuclear matter. The critical
density and proton fraction for the phase transition are determined in the mean
field approximation. Droplet properties are calculated in the Thomas-Fermi
approximation. The electromagnetic field is explicitly included and its effects
on droplet properties are studied. The results are compared with the ones
obtained with the NL1 parametrization of the non-linear Walecka model.


title:
Integral Equation Results for the 4He(e,e'p)3H Reaction at High Missing
  Momenta

abstract:
  The two-fragment electrodisintegration of 4He into proton and triton is
calculated in Plane Wave Impulse Approximation (PWIA). The three- and
four-nucleon wave functions involved are obtained by solving the
Alt-Grassberger-Sandhas (AGS) integral equations, with the Malfliet-Tjon
potential as the underlying NN-interaction. Our results are in remarkable
agreement with the experimental data and, in contrast to alternative
approaches, do not exhibit any dip in the five-fold differential cross section
at a missing momentum of ~ 450 MeV/c.


title: Many-body correlations in a multistep variational approach

abstract:
  We discuss a multistep variational approach for the study of many-body
correlations. The approach is developed in a boson formalism (bosons
representing particle-hole excitations) and based on an iterative sequence of
diagonalizations in subspaces of the full boson space. Purpose of these
diagonalizations is that of searching for the best approximation of the ground
state of the system. The procedure also leads us to define a set of excited
states and, at the same time, of operators which generate these states as a
result of their action on the ground state. We examine the cases in which these
operators carry one-particle one-hole and up to two-particle two-hole
excitations. We also explore the possibility of associating bosons to
Tamm-Dancoff excitations and of describing the spectrum in terms of only a
selected group of these. Tests within an exactly solvable three-level model are
provided.


title:
Intermittent, Domain-Structured Coherence in the Pion Interferometry of
  Relativistic Nuclear Collisions

abstract:
  We investigate a domain-structured source in the pion interferometry of
relativistic nuclear collisions. The source emits coherent pions intermittently
with the background of chaotic pions. The coherent pions examined are either of
a general nature or of disoriented chiral condensate. Two- and three-pion
correlations for the source are shown to agree well with the recent NA44
experimental data.


abstract:
  Deuteron Compton scattering below pion photoproduction threshold is
considered in the framework of the nonrelativistic diagrammatic approach with
the Bonn OBE potential. A complete gauge-invariant set of diagrams is taken
into account which includes resonance diagrams without and with NN-rescattering
and diagrams with one- and two-body seagulls. The seagull operators are
analyzed in detail, and their relations with free- and bound-nucleon
polarizabilities is discussed. It is found that both dipole and higher-order
polarizabilities of the nucleon are needed for a quantitative description of
recent experimental data. An estimate of the isospin-averaged dipole
electromagnetic polarizabilities of the nucleon and the polarizabilities of the
neutron is obtained from the data.


title:
Microscopic analysis of a correlation between dipole transitions $1^-_1
  \to 0^+_{g.s.}$ and $3^-_1 \to 2^+_{1}$ in spherical nuclei

abstract:
  Correlation between B($E1, 1^-_1 \to 0^+_{g.s.}$) and B($E1, 3^-_1 \to
2^+_{1}$) values are considered within microscopic QRPA approach. General
arguments for a dependence of a ratio between these values on a collectivity of
the $2^+_1$ and $3^-_1$ phonons and ground state correlations are provided.


title: Pion Electroproduction on the Nucleon and the Generalized GDH Sum Rule

abstract:
  We present predictions for the spin structure functions of the proton and the
neutron in the framework of a unitary isobar model for one-pion photo- and
electroproduction. Our results are compared with recent experimental data from
SLAC. The first moments of the calculated structure functions fulfill the
Gerasimov-Drell-Hearn and Burkhardt-Cottingham sum rules within an error of
typically 5-10% for the proton. For the neutron target we find much bigger
deviations, in particular the sum rule for I_1(0)+I_2(0) is heavily violated.


title:
A Linear Approximation for the Excitation Energies of single and double
  analog states in the f_{7/2} shell

abstract:
  We find that the excitation energies of single analog states for odd-even
nuclei in the f$_{7/2}$ shell with J=j=7/2$^{-}$ and the J=0$^{+}$ double
analog states in the even-even nuclei are well described by the formulas
$E^{*}(j,T+1) = b (T+X)$ and $E^{*}(0^{+},T+2) = 2b (T+X+0.5)$,respectively,
where $T=\mid N-Z\mid /2$ is usually the ground state isospin. It is remarkable
to note that the parameter X accounts for the departures from the symmetry
energy based predictions.


title: Nonabelian density functional theory

abstract:
  Given a vector space of microscopic quantum observables, density functional
theory is formulated on its dual space. A generalized Hohenberg-Kohn theorem
and the existence of the universal energy functional in the dual space are
proven. In this context ordinary density functional theory corresponds to the
space of one-body multiplication operators. When the operators close under
commutation to form a Lie algebra, the energy functional defines a Hamiltonian
dynamical system on the coadjoint orbits in the algebra's dual space. The
enhanced density functional theory provides a new method for deriving the group
theoretic Hamiltonian on the coadjoint orbits from the exact microscopic
Hamiltonian.


title: Algebraic nonlinear collective motion

abstract:
  Finite-dimensional Lie algebras of vector fields determine geometrical
collective models in quantum and classical physics. Every set of vector fields
on Euclidean space that generates the Lie algebra sl(3, R) and contains the
angular momentum algebra so(3) is determined. The subset of divergence-free
sl(3, R) vector fields is proven to be indexed by a real number $\Lambda$. The
$\Lambda=0$ solution is the linear representation that corresponds to the
Riemann ellipsoidal model. The nonlinear group action on Euclidean space
transforms a certain family of deformed droplets among themselves. For positive
$\Lambda$, the droplets have a neck that becomes more pronounced as $\Lambda$
increases; for negative $\Lambda$, the droplets contain a spherical bubble of
radius $|\Lambda|^{{1/3}}$. The nonlinear vector field algebra is extended to
the nonlinear general collective motion algebra gcm(3) which includes the
inertia tensor. The quantum algebraic models of nonlinear nuclear collective
motion are given by irreducible unitary representations of the nonlinear gcm(3)
Lie algebra. These representations model fissioning isotopes ($\Lambda>0$) and
bubble and two-fluid nuclei ($\Lambda<0$).


title: Algebraic mean field theory

abstract:
  Mean field theory has an unexpected group theoretic mathematical foundation.
Instead of representation theory which applies to most group theoretic quantum
models, Hartree-Fock and Hartree-Fock-Bogoliubov have been formulated in terms
of coadjoint orbits for the groups U(n) and O(2n). The general theory of mean
fields is formulated for any arbitrary Lie algebra {\textbf g} of fermion
operators. The moment map provides the correspondence between the Hilbert space
of microscopic wave functions and the dual space {\textbf g}$^\ast$ of
densities. The coadjoint orbits of the group in the dual space are phase spaces
on which time-dependent mean field theory is equivalent to a classical
Hamiltonian dynamical system. Indeed it forms a finite-dimensional Lax system.
The SU(3) mean field theory is constructed explicitly in the coadjoint orbit
framework.


title: Relativistic transport equations with generalized mass shell constraints

abstract:
  We reexamine the derivation of relativistic transport equations for fermions
when conserving the most general spinor structure of the interaction and Green
function. Such an extension of the formalism is needed when dealing with {\it
e.g.} spin-polarized nuclear matter or non-parity conserving interactions. It
is shown that some earlier derivations can lead to an incomplete description of
the evolution of the system even in the case of parity-conserving,
spin-saturated systems. The concepts of kinetic equation and mass shell
condition have to be extended, in particular both of them acquire a non trivial
spinor structure which describe a rich polarization dynamics.


title: Triaxial bifurcations of rapidly rotating spheroids

abstract:
  A rotating system, such as a star, liquid drop, or atomic nucleus, may rotate
as an oblate spheroid about its symmetry axis or, if the angular velocity is
greater than a critical value, as a triaxial ellipsoid about a principal axis.
The oblate and triaxial equilibrium configurations minimize the total energy, a
sum of the rotational kinetic energy plus the potential energy. For a star or
galaxy the potential is the self-gravitating potential, for a liquid drop, the
surface tension energy, and for a nucleus, the potential is the sum of the
repulsive Coulomb energy plus the attractive surface energy. A simple, but
accurate, Pad\'{e} approximation to the potential function is used for the
energy minimization problem that permits closed analytic expressions to be
derived. In particular, the critical deformation and angular velocity for
bifurcation from MacLaurin spheroids to Jacobi ellipsoids is determined
analytically in the approximation.


title:
Rescattering of Vector Meson Daughters in High Energy Heavy Ion
  Collisions

abstract:
  We consider the role of hadronic rescattering of daughter kaons on the
observed mass spectra from $\phi$ meson decays in ultra-relativistic heavy ion
collisions. A hadronic cascade code (RQMD v2.4) shows that $\sim$26% of all
$\phi$'s decaying to $K^+K^-$ in central Pb+Pb collisions at SPS energies
($E_{beam} = 158 GeV/A$) have a rescattered or absorbed daughter. This
significantly affects the reconstructed invariant mass of the pair and shifts
$\phi$ mesons out of the mass peak. Kaon rescattering depletes the low velocity
region, hardening and broadening the observed phi $m_t$ and rapidity
distributions respectively, relative to the dilepton channel. This effect
produces an apparent change in the experimentally determined branching ratio
not necessarily related to chiral symmetry restoration. Comparisons to recent
experimental measures at CERN energies reveal a possible mechanism to account
for the shape of the observed spectra, though not their absolute relative
magnitude.


title:
Field transformations and simple models illustrating the impossibility
  of measuring off-shell effects

abstract:
  In the context of simple models illustrating field transformations in
Lagrangian field theories we discuss the impossibility of measuring off-shell
effects in nucleon-nucleon bremsstrahlung, Compton scattering, and related
processes. To that end we introduce a simple phenomenological Lagrangian
describing nucleon-nucleon bremsstrahlung and perform an appropriate change of
variables leading to different off-shell behavior in the nucleon-nucleon
amplitude as well as the photon-nucleon vertex. As a result we obtain a class
of equivalent Lagrangians, generating identical S-matrix elements, of which the
original Lagrangian is but one representative. We make use of this property in
order to show that what appears as an off-shell effect in an S-matrix element
for one Lagrangian may originate in a contact term from an equivalent
Lagrangian. By explicit calculation we demonstrate for the case of
nucleon-nucleon bremsstrahlung as well as nucleon Compton scattering the
equivalence of observables from which we conclude that off-shell effects cannot
in any unambiguous way be extracted from an S-matrix element. Finally, we also
discuss some implications of introducing off-shell effects on a
phenomenological basis, resulting from the requirement that the description of
one process be consistent with that of other processes described by the same
Lagrangian.


title: Theory of Nuclear Reactions Leading to Superheavy Elements

abstract:
  Dynamical reaction theory is presented for synthesis of superheavy elements.
Characteristic features of formation and surviving are discussed, which
combinedly determine final residue cross sections of superheavy elements.
Preliminary results on Z=114 are also given.


title:
Higher Dimension Operators and Chiral Symmetry Breaking in
  Nambu-Jona-Lasinio Model

abstract:
  We point out that adding higher dimension operators to the Nambu-Jona-Lasinio
model can stabilize chiral symmetry breaking and resolve the issue raised by
Kleinert and Van den Bossche that chiral symmetry breaking cannot occur for
$N_c \le N_c^{{\rm cr}}$ due to large quantum fluctuations of the composite
fields.


title: Triaxiality in 48Cr

abstract:
  Rotational behavior inducing triaxiality is discussed for 48Cr in the cranked
Nilsson-Strutinsky (CNS) model, as well as in the spherical shell model. It is
shown that the low-spin region up to about I=8, has a prolate well-deformed
shape. At higher spins the shape is triaxial with a "negative-gamma"
deformation, that is, with rotation around the classically forbidden
intermediate axis. By comparing calculated B(E2)-values and spectroscopic
quadrupole moments in the CNS with spherical shell model results and
experimental data, the triaxial rotation around the intermediate axis is
confirmed.


title:
Towards a test particle description of transport processes for states
  with continuous mass spectra

abstract:
  Based on a first order gradient expansion a consistent transport equation is
derived for a nonrelativistic system beyond the quasiparticle approximation,
i.e. for a regime where the dynamically generated width of the states is
allowed to be large. An exactly conserved quantity is identified which is
interpreted as an effective particle number obtained by coarse graining. Using
a test particle ansatz for this conserved quantity allows to rewrite the
transport equation into equations of motion for test particles. The two-body
collision terms are formulated in terms of the test particles which gain
non-trivial renormalization factors due to the coarse graining process.


title:
Selected Topics in Astro-Hadron Physics: Going from a Proton to Nuclei
  to Neutron Stars

abstract:
  The effort currently in vogue in some small circle of physicists to go from a
proton to nuclei to compact stars involves various aspects of particle and
nuclear physics that require input from laboratory experiments, transcending
narrow specialization in diverse sub-fields. Several topics on this matter are
discussed in this note. The notion of Cheshire Cat Principle is introduced for
nucleons, nuclei and dense hadronic matter and is confronted with experimental
data on the proton, two-nucleon systems and heavy-ion experiments, with a
leaping extrapolation to the structure of neutron stars. The matter discussed
here illustrates that a close contact with experiments, indispensable in the
present case, is essential for significant progress in {\it any} field of
physics. I suggest that this is a field that has a tremendous potential for
breakthrough in the Asia Pacific countries, particularly in Korea, where some
of the seminal works in this area have been done by young theorists, both pre-
and post-graduate.


title: Current Conservation in the Covariant Quark-Diquark Model of the Nucleon

abstract:
  The description of baryons as fully relativistic bound states of quark and
glue reduces to an effective Bethe-Salpeter equation with quark-exchange
interaction when irreducible 3-quark interactions are neglected and separable
2-quark (diquark) correlations are assumed. This covariant quark-diquark model
of baryons is studied with the inclusion of the quark substructure of the
diquark correlations. In order to maintain electromagnetic current conservation
it is then necessary to go beyond the impulse approximation. A conserved
current is obtained by including the coupling of the photon to the exchanged
quark and direct ``seagull'' couplings to the diquark structure. Adopting a
simple dynamical model of constituent quarks and exploring various
parametrisations of scalar diquark correlations, the nucleon Bethe-Salpeter
equation is solved and the proton and neutron electromagnetic form factors are
calculated numerically. The resulting magnetic moments are still about 50% too
small, the improvements necessary to remedy this are discussed. The results
obtained in this framework provide an excellent description of the electric
form factors (and charge radii) of the proton, up to a photon momentum transfer
of 3.5GeV^2, and the neutron.


title: Integral equations for three-body Coulombic resonances

abstract:
  We propose a novel method for calculating resonances in three-body Coulombic
systems. The method is based on the solution of the set of Faddeev and
Lippmann-Schwinger integral equations, which are designed for solving the
three-body Coulomb problem. The resonances of the three-body system are defined
as the complex-energy solutions of the homogeneous Faddeev integral equations.
We show how the kernels of the integral equations should be continued
analytically in order that we get resonances. As a numerical illustration a toy
model for the three-$\alpha$ system is solved.


title:
Relationship of field-theory based single boson exchange potentials to
  current ones

abstract:
  It is shown that field-theory based single boson exchange potentials cannot
be identified to those of the Yukawa or Coulomb type that are currently
inserted in the Schr\"odinger equation. The potential which is obtained rather
corresponds to this current single boson exchange potential corrected for the
probability that the system under consideration is in a two-body component,
therefore missing contributions due to the interaction of these two bodies
while bosons are exchanged. The role of these contributions, which involve at
least two boson exchanges, is examined. The conditions that allow one to
recover the usual single boson exchange potential are given. It is shown that
the present results have some relation: i) to the failure of the Bethe-Salpeter
equation in reproducing the Dirac or Klein-Gordon equations in the limit where
one of the constituent has a large mass, ii) to the absence of corrections of
relative order alpha log(1/alpha) to a full calculation of the binding energy
in the case of neutral massless bosons or iii) to large corrections of
wave-functions calculated perturbatively in some light-front approaches.


title: Binomial level densities

abstract:
  It is shown that nuclear level densities in a finite space are described by a
continuous binomial function, determined by the first three moments of the
Hamiltonian, and the dimensionality of the underlying vector space.
Experimental values for $^{55}$Mn, $^{56}$Fe, and $^{60}$Ni are very well
reproduced by the binomial form, which turns out to be almost perfectly
approximated by Bethe's formula with backshift. A proof is given that binomial
densities reproduce the low moments of Hamiltonians of any rank: A strong form
of the famous central limit result of Mon and French. Conditions under which
the proof may be extended to the full spectrum are examined.


title: Canonical form of Hamiltonian matrices

abstract:
  On the basis of shell model simulations, it is conjectured that the Lanczos
construction at fixed quantum numbers defines---within fluctuations and
behaviour very near the origin---smooth canonical matrices whose forms depend
on the rank of the Hamiltonian, dimensionality of the vector space, and second
and third moments. A framework emerges that amounts to a general Anderson model
capable of dealing with ground state properties and strength functions. The
smooth forms imply binomial level densities. A simplified approach to canonical
thermodynamics is proposed.


title:
Modifications of the Rho Meson from the Virtual Pion Cloud in Hot and
  Dense Matter

abstract:
  The modification of the rho-meson self-energy due to the coupling to
in-medium pions is calculated consistently at finite baryon density and
temperature, keeping the full 3-momentum dependence in a gauge invariant way.
As a function of nucleon density, the rho-meson spectral function is strongly
enhanced in the invariant mass region M < 650 MeV, while the maximum, i.e. the
pole mass, is slightly shifted upwards. As a function of temperature, for fixed
nucleon density, the imaginary part of the self-energy increases further due to
Bose-enhancement. At the same time the mass shift from the real part becomes
very large. As a consequence of these medium effects, the dilepton rate in the
low-mass region M < 650 MeV increases strongly, while the peak at M = 770 MeV
disappears.


title:
Low Energy Behavior of the \protect(^{7}\protect) Be \protect(
  (p,\gamma)^{8}\protect) B reaction

abstract:
  Three related features of the astrophysical S-factor, (S_{17}), for low
energies are an upturn as the energy of the proton goes to zero, a pole at the
proton separation energy and a long ranged radial integral peaking at
approximately 40 fm. These features, particularly the last, mean (S_{17}) at
threshold is largely determined by the asymptotic normalization of the proton
bound-state wave function. In this paper we show that by taking the pole
explicitly into account, (S_{17}) can be calculated in terms of purely short
range integrals involving the two-body potential. Much of the discusion is
relevant to other radiative capture processes especially those wth weakly bound
final states.


title: Describing the nucleon and its form factors at high q**2

abstract:
  The nucleon form factors are calculated using a non-relativistic description
in terms of constituent quarks. The emphasis is put on the reliability of
present numerical methods used to solve the three-body problem in order to
correctly reproduce the expected asymptotic behavior of form factors. Nucleon
wave functions obtained in the hyperspherical formalism or employing Faddeev
equations have been considered. While a q**(-8) behavior is expected at high q
for a quark-quark force behaving like 1/r at short distances, it is found that
the hypercentral approximation in the hyperspherical formalism (K=0) leads to a
q**(-7) behavior. An infinite set of waves is required to get the correct
behavior. Solutions of the Faddeev equations lead to the q**(-8) behavior. The
amplitude of the corresponding term however depends on the number of partial
waves retained in the Faddeev amplitude. The convergence to the asymptotic
behavior has also been studied. Sizeable departures are observed in some cases
at squared momentum transfers as high as 50 (GeV/c)**2. It is not clear whether
these departures are of the order 1/q or 1/q**2 log q relatively to the
dominant contribution and whether the bad convergence results from truncations
in the calculations. From a comparison with the most complete Faddeev results,
a q**2 validity range is obtained for the calculation made in the
hyperspherical formalism or in the Faddeev approach with the minimum number of
amplitudes.


title:
Microscopic calculation of the inclusive electron scattering structure
  function in O-16

abstract:
  We calculate the charge form factor and the longitudinal structure function
for $^{16}$O and compare with the available experimental data, up to a momentum
transfer of 4 fm$^{-1}$. The ground state correlations are generated using the
coupled cluster [exp(S}] method, together with the realistic v-18 NN
interaction and the Urbana IX three-nucleon interaction. Center-of-mass
corrections are dealt with by adding a center-of-mass Hamiltonian to the usual
internal Hamiltonian, and by means of a many-body expansion for the computation
of the observables measured in the center-of-mass system.


title:
Nuclear Octupole Correlations and the Enhancement of Atomic
  Time-Reversal Violation

abstract:
  We examine the time-reversal-violating nuclear ``Schiff moment'' that induces
electric dipole moments in atoms. After presenting a self-contained derivation
of the form of the Schiff operator, we show that the distribution of Schiff
strength, an important ingredient in the ground-state Schiff moment, is very
different from the electric-dipole-strength distribution, with the Schiff
moment receiving no strength from the giant dipole resonance in the
Goldhaber-Teller model. We then present shell-model calculations in light
nuclei that confirm the negligible role of the dipole resonance and show the
Schiff strength to be strongly correlated with low-lying octupole strength.
Next, we turn to heavy nuclei, examining recent arguments for the strong
enhancement of Schiff moments in octupole-deformed nuclei over that of 199Hg,
for example. We concur that there is a significant enhancement while pointing
to effects neglected in previous work (both in the octupole-deformed nuclides
and 199Hg) that may reduce it somewhat, and emphasizing the need for
microscopic calculations to resolve the issue. Finally, we show that static
octupole deformation is not essential for the development of collective Schiff
moments; nuclei with strong octupole vibrations have them as well, and some
could be exploited by experiment.


title:
Elastic electron deuteron scattering with consistent meson exchange and
  relativistic contributions of leading order

abstract:
  The influence of relativistic contributions to elastic electron deuteron
scattering is studied systematically at low and intermediate momentum transfers
($Q^2\leq 30$ fm$^{-2}$). In a $(p/M)$-expansion, all leading order
relativistic $\pi$-exchange contributions consistent with the Bonn OBEPQ models
are included. In addition, static heavy meson exchange currents including boost
terms and lowest order $\rho\pi\gamma$-currents are considered. Sizeable
effects from the various relativistic two-body contributions, mainly from
$\pi$-exchange, have been found in form factors, structure functions and the
tensor polarization $T_{20}$. Furthermore, static properties, viz. magnetic
dipole and charge quadrupole moments and the mean square charge radius are
evaluated.


title:
Threshold Behaviour of Meson-Nucleon-$S_{11}$(1535) Vertexfunctions and
  Determination of the $S_{11}$(1535) Mixing Angle

abstract:
  A new method for the determination of the spin-1/2-3/2-mixing angle and the
range parameter of the quarkmodel wavefunction of the resonance
$S^-_{11}(1535)$ is presented. The method ist based on a quantitative
calculation of the total cross section of $pp\to pp\eta$ at threshold. The
quantitative on-shell treatment of ISI and FSI is discussed.


title: Charge Symmetry Violation Effects in Pion Scattering off the Deuteron

abstract:
  We discuss the theoretical and experimental situations for charge symmetry
violation (CSV) effects in the elastic scattering of pi+ and pi- on deuterium
(D) and 3He/3H. Accurate comparison of data for both types of targets provides
evidence for the presence of CSV effects. While there are indications of a CSV
effect in deuterium, it is much more pronounced in the case of 3He/3H. We
provide a description of the CSV effect on the deuteron in terms of single- and
double- scattering amplitudes. The Delta-mass splitting is taken into account.
Theoretical predictions are compared with existing experimental data for pi-d
scattering; a future article will speak to the pi-three nucleon case.


title:
Baryon Resonance Extraction from piN Data using a Unitary Multichannel
  Model

abstract:
  A unitary multi-channel approach, first developed by the Carnegie-Mellon-
Berkeley group, is applied to extract the pole positions, masses, and partial
decay widths of nucleon resonances. Input used are the partial wave amplitudes
for the transitions from piN to eight possible final baryon-meson final states.
Because the model preserves analyticity, resonances are found as poles in the T
matrix. This approach is designed to handle inelastic threshold openings with
minimal model dependence. Although many of the known states have the same
properties as in previous analyses, others change significantly. We pay
particular attention to S11(1535) which is very close to the eta threshold.


title: Restoration of rotational invariance of bound states on the light front

abstract:
  We study bound states in a model with scalar nucleons interacting via an
exchanged scalar meson using the Hamiltonian formalism on the light front. In
this approach manifest rotational invariance is broken when the Fock space is
truncated. By considering an effective Hamiltonian that takes into account two
meson exchanges, we find that this breaking of rotational invariance is
decreased from that which occurs when only one meson exchange is included. The
best improvement occurs when the states are weakly bound.


title: Kaonic nuclei excited by the $(K^-,N)$ reaction

abstract:
  We show that kaonic nuclei can be produced by the $(K^-,p)$ and $(K^-,n)$
reactions. The reactions are shown to have cross sections experimentally
measurable. The observation of the kaonic nuclei gives a kaon-nucleus potential
which answers the question on the existence of kaon condensation in dense
nuclear matter especially neutron stars.


title: Monopole, quadrupole and pairing: a shell model view

abstract:
  The three main contributions to the nuclear Hamiltonian - monopole,
quadrupole and pairing - are analyzed in a shell model context. The first has
to be treated phenomenologically, while the other two can be reliably extracted
from the realistic interactions. Due to simple scaling properties, the
realistic quadrupole and pairing interactions eliminate the tendency to
collapse of their conventional counterparts, while retaining their basic
simplicity.


title:
In-Medium Modifications of Hadron Masses and Chemical Freeze-Out in
  Ultra-Relativistic Heavy-Ion Collisions

abstract:
  We confront the hypothesis of chemical freeze-out in ultra-relativistic
heavy-ion collisions with the hypothesis of large modifications of hadron
masses in nuclear medium. We find that the thermal-model predictions for the
ratios of particle multiplicities are sensitive to the values of in-medium
hadronic masses. In particular, the $\pi^+/p$ ratio decreases by 35% when the
masses of all hadrons (except for pseudo-Goldstone bosons) are scaled down by
30%.


title:
Cherenkov-like shock waves associated with surpassing the light velocity
  barrier

abstract:
  The effects arising from accelerated and decelerated motion of a point charge
inside a medium are studied. The motion is manifestly relativistic and may be
produced by a constant uniform electric field. It is shown that in addition to
the bremsstrahlung and Cherenkov shock waves, the electromagnetic shock wave
arises when the charge particle velocity coincides with the light velocity in
the medium. For the accelerated motion this shock wave forming an indivisible
entity with the Cherenkov shock wave arrives after the arrival of the
bremsstrahlung shock wave. For the decelerated motion the above shock wave
detaches from the charge at the moment when its velocity coincides with the
light velocity in the medium. This wave existing even after termination of the
charge motion of the charge propagates with the light velocity in the medium.
It has the same singularity as the Cherenkov shock and is more singular than
the bremsstrahlung shock wave. The space-time regions, where these shock waves
exist, and conditions under which they can be observed are determined.


title:
Possibility of time reversal symmetry violation at proton deuteron
  forward elastic scattering

abstract:
  We consider T-violating P-conserving proton-deuteron forward elastic
scattering amplitude in a frame of the Glauber multiscattering theory,
proceeding from T-odd, P-even N-N interaction.


title: Working group summary: Isospin violation

abstract:
  I give an introduction to the problem of isospin violation and add some
comments to the various topics addressed in the working group.


title:
Semi-inclusive electron scattering off the deuteron and the neutron
  structure functions

abstract:
  The detection of slow nucleons in semi-inclusive electron scattering
processes off the deuteron, 2H(e, e'N)X, is a very promising tool for the
extraction of model-independent information on the neutron structure function
F2n(x, Q**2). The key point is the occurrence of a peculiar scaling property of
the semi-inclusive cross section, which holds in the deep-inelastic regime as
well as in the nucleon-resonance production regions. Moreover, the possibility
to get unique information on the neutron asymmetry A1n(x, Q**2) from polarised
2H_pol(e_pol, e'N)X processes is illustrated.


title:
Solar proton burning, neutrino disintegration of the deuteron and pep
  process in the relativistic field theory model of the deuteron

abstract:
  The astrophysical factor S_pp(0) for the solar proton burning, p + p -> D +
positron + neutrino, is recalculated in the relativistic field theory model of
the deuteron (RFMD). We obtain S_pp(0) = 4.08 x 10^{-25} MeV b which agrees
good with the recommended value S_pp(0) = 4.00 x 10^{-25} MeV b. The amplitude
of low-energy elastic proton-proton (pp) scattering in the singlet S-wave state
with the Coulomb repulsion contributing to the amplitude of the solar proton
burning is described in terms of the S-wave scattering length and the effective
range. This takes away the problem pointed out by Bahcall and Kamionkowski
(Nucl. Phys. A625 (1997) 893) that in the RFMD one cannot describe low-energy
elastic pp scattering with the Coulomb repulsion in agreement with low-energy
nuclear phenomenology. The cross section for the neutrino disintegration of the
deuteron, neutrino + D -> electron + p + p, is calculated with respect to
S_pp(0) for neutrino energies from threshold to 10 MeV. The results can be used
for the analysis of the data which will be obtained in the experiments planned
by SNO. The astrophysical factor S_pep(0) for the pep process, p + electron + p
-> neutrino + D, is calculated relative to S_pp(0) in complete agreement with
the result obtained by Bahcall and May (ApJ. 155 (1969) 501).


title: Semiclassical and quantum production rates

abstract:
  We discuss the effects of the off-shell nucleon propagation for the particle
production. Results from nonequilibrium Kadanoff-Baym evolution modeling a
heavy ion collision are presented. The production rates are compared to
equilibrium emission rates obtained in the same approximation for the
self-energy. The comparison of semiclassical and quantum in-medium production
rates is performed within the T-matrix approximation. Self-consistent T-matrix
resummation allows us to discuss also the effect of the off-shell propagation
on the effective in-medium cross section.


title: The Role of Gluons in Dilepton Production from the Quark-Gluon Plasma

abstract:
  We study high mass dilepton production from gluon-induced processes, $g q \to
q \gamma^*$, $g \bar q \to \bar q \gamma^*$, and $g g \to q \bar q \gamma^*$,
in a thermally equilibrated but chemically under-saturated partonic matter that
is expected to be created in the initial stage of ultra-relativistic heavy ion
collisions. Regulating the divergence in these processes by the thermal quark
mass, we find that gluon-induced processes are more important than the
leading-order $q\bar q$ annihilation process as a result of the larger number
of gluons than quarks in the partonic matter. The dependence of the thermal
dilepton yield from the partonic stage of heavy ion collisions on the initial
conditions for the partonic matter is also studied. We further discuss the
feasibility of observing thermal dileptons from the quark-gluon plasma in heavy
ion experiments.


title: Electron scattering with a short-range correlation model

abstract:
  The inclusive electromagnetic responses in the quasi-elastic region are
calculated with a model which considers the terms of the cluster expansion
containinga single correlation line. The validity of this model is studied by
comparing, in nuclear matter, its results with those of a complete calculation.
Results in finite nuclei for both one-and two-nucleon emission are presented.


title:
Consequences of the center-of-mass correction in nuclear mean-field
  models

abstract:
  We study the influence of the scheme for the correction for spurious
center-of-mass motion on the fit of effective interactions for self-consistent
nuclear mean-field calculations. We find that interactions with very simple
center-of-mass correction have significantly larger surface coefficients than
interactions for which the center-of-mass correction was calculated for the
actual many-body state during the fit. The reason for that is that the
effective interaction has to counteract the wrong trends with nucleon number of
all simplified schemes for center-of-mass correction which puts a wrong trend
with mass number into the effective interaction itself. The effect becomes
clearly visible when looking at the deformation energy of largely deformed
systems, e.g. superdeformed states or fission barriers of heavy nuclei.


title: Pairing Gap and Polarisation Effects

abstract:
  The phenomenological adjustment of the nuclear pairing strength is usually
performed with respect to the odd-even staggering of the binding energies. We
find that the results strongly depend on the way in which the ground states of
the odd nuclei are computed. A thorough calculation including all time-even and
time-odd polarisation effects induced by the odd nucleon produces about 30%
reduced odd-even staggering as compared to the standard spherical calculations
in the relativistic mean-field model. The pairing strength must be enhanced by
about 20% to compensate for that effect. The enhanced strength has dramatic
consequences for the predicted deformation properties of the underlying
mean-field models, possibly implying that new adjustments of their parameters
become necessary as well.


title: Breakup of $^8$B and the $^7$Be($p,\gamma)^8$B reaction

abstract:
  The calculated rate of events in some of the existing solar neutrino
detectors is directly proportional to the rate of the $^7$Be($p,\gamma)^8$B
reaction measured in the laboratory at low energies. However, the low-energy
cross sections of this reaction are quite uncertain as various measurements
differ from each other by 30-40 %. The Coulomb dissociation process which
reverses the radiative capture by the dissociation of $^8$B in the Coulomb
field of a target, provides an alternate way of accessing this reaction. While
this method has several advantages (like large breakup cross sections and
flexibility in the kinematics), the difficulties arise from the possible
interference by the nuclear interactions, uncertainties in the contributions of
the various multipoles and the higher order effects, which should be considered
carefully. We review the progress made so far in the experimental measurements
and theoretical analysis of the breakup of $^8$B and discuss the current status
of the low-energy cross sections (or the astrophysical $S$-factor) of the
$^7$Be($p,\gamma)^8$B reaction extracted therefrom. The future directions of
the experimental and theoretical investigations are also suggested.


title:
Studying the $\omega N$ elastic and inelastic cross section with
  nucleons

abstract:
  We explore the possibility to measure the elastic and inelastic $\omega N$
cross section in $p{+}d{\to}d{+}\omega{+}p_{sp}$ and $p{+}A$ reactions. Our
studies indicate that the elastic scattering cross sections can be determined
for $\omega$ momenta above 1 GeV/c in $p{+}d$ reactions by gating on high
proton spectator momenta whereas the $\omega N$ absorption cross section down
to low relative $\omega$ momenta is most effectively studied in $p{+}A$
reactions at beam energies 2.0--2.7 GeV


title: K -> pi pi and a light scalar meson

abstract:
  We explore the Delta-I= 1/2 rule and epsilon'/epsilon in K -> pi pi
transitions using a Dyson-Schwinger equation model. Exploiting the feature that
QCD penguin operators direct K^0_S transitions through 0^{++} intermediate
states, we find an explanation of the enhancement of I=0 K -> pi pi transitions
in the contribution of a light sigma-meson. This mechanism also affects
epsilon'/epsilon.


title: Uranium on uranium collisions at relativistic energies

abstract:
  Deformation and orientation effects on compression, elliptic flow and
particle production in uranium on uranium collisions (UU) at relativistic
energies are studied within the transport model ART. The density compression in
tip-tip UU collisions is found to be about 30% higher and lasts approximately
50% longer than in body-body or spherical UU reactions. The body-body UU
collisions have the unique feature that the nucleon elliptic flow is the
highest in the most central collisions and remain a constant throughout the
reaction. We point out that the tip-tip UU collisions are more probable to
create the QGP at AGS and SPS energies while the body-body UU collisions are
more useful for studying properties of the QGP at higher energies.


title:
Annihilation of antiprotons on nuclear targets at low energies: a simple
  analysis

abstract:
  We set up a plane wave impulse approximation (PWIA) formalism for the
analysis of the annihilation cross sections of antinucleons on nuclear targets
at very low momenta (below 100 MeV/c), where semiclassical approximations can't
be applied. Since, as we test here, PWIA fails in reproducing the unexpected
``inversion'' behavior of the $\bar{p}p$ and $\bar{p}-$nucleus annihilation
cross sections found in a recent experiment\cite{obe1,obe2} we discuss some
further possibilities, with a special attention to the optical potential model.


title:
Configuration mixing of mean-field wave-functions projected on angular
  momentum and particle number; application to 24Mg

abstract:
  We present in this paper the general framework of a method which permits to
restore the rotational and particle number symmetries of wave functions
obtained in Skyrme HF+BCS calculations. This restoration is nothing but a
projection of mean-field intrinsic wave functions onto good particle number and
good angular momentum. The method allows also to mix projected wave functions.
Such a configuration mixing is discussed for sets of HF+BCS intrinsic states
generated in constrained calculations with suitable collective variables. This
procedure gives collective states which are eigenstates of the particle number
and the angular momentum operators and between which transition probabilities
are calculated. An application to 24Mg is presented, with mean-field wave
functions generated by axial quadrupole constraints. Theoretical spectra and
transition probabilities are compared to the experiment.


title: The Quark-Photon Vertex and the Pion Charge Radius

abstract:
  The rainbow truncation of the quark Dyson-Schwinger equation is combined with
the ladder Bethe-Salpeter equation for the dressed quark-photon vertex to study
the low-momentum behavior of the pion electromagnetic form factor. With model
gluon parameters previously fixed by the pion mass and decay constant, the pion
charge radius $r_\pi$ is found to be in excellent agreement with the data. When
the often-used Ball-Chiu Ansatz is used to construct the quark-photon vertex
directly from the quark propagator, less than half of $r_\pi^2$ is generated.
The remainder of $r^2_\pi$ is seen to be attributable to the presence of the
$\rho$-pole in the solution of the ladder Bethe-Salpeter equation.


title: New Three-Nucleon-Force Terms in the Three-Nucleon System

abstract:
  We include two new three-nucleon-force terms of pion-range - short-range form
in our momentum-space calculations for the three-nucleon continuum. These two
terms are expected by chiral perturbation theory to be non-negligible. We study
the effects of these terms in elastic neutron-deuteron scattering and pay
special attention to the neutron vector analyzing power $A_y$.


title: Small size boundary effects on two-pion interferometry

abstract:
  The Bose-Einstein correlations of two identically charged pions are derived
when these particles, the most abundantly produced in relativistic heavy ion
collisions, are confined in finite volumes. Boundary effects on single pion
spectrum are also studied. Numerical results emphasize that conventional
formulation usually adopted to describe two-pion interferometry should not be
used when the source size is small, since this is the most sensitive case to
boundary effects. Specific examples are considered for better illustration.


title: Generalized Polarizabilities of the Nucleon in Chiral Effective Theories

abstract:
  Using the techniques of chiral effective field theories we evaluate the so
called generalized polarizabilities of the nucleon, which characterize the
structure dependent components in virtual Compton scattering (VCS) as probed in
the electron scattering reaction e N \to e' N gamma. Results are given for both
spin-dependent and spin-independent structure effects to O(p^3) in SU(2) Heavy
Baryon Chiral Perturbation Theory and to O(epsilon^3) in the SU(2) Small Scale
Expansion. Finally we compare our calculations with results from the pioneering
VCS experiment on the proton from Mainz.


title:
A Practical Method for Relativistic 3N-Scattering Calculations with
  Realistic Potentials

abstract:
  Using a scale transformation in momentum space a phase equivalent
relativistic potential is generated from the nonrelativistic potential. By that
transformation a practical method for the relativistic 3N scattering with
realistic nucleon-nucleon potentials is introduced. The formalism can be
applied to any realistic nonrelativistic potential. We also discuss the
locations of the moving logarithmic singularities of the free relativistic
three-body Green's function. It enters in the relativistic 3N Faddeev
equations, which have been formulated long time ago for a 3-boson bound state
and which we propose to also use for 3N scattering. Finally we compare
relativistic deuteron wave functions to nonrelativistic ones.


title: Nuclear Matter on a Lattice

abstract:
  We investigate nuclear matter on a cubic lattice. An exact thermal formalism
is applied to nucleons with a Hamiltonian that accommodates on-site and
next-neighbor parts of the central, spin- and isospin-exchange interactions. We
describe the nuclear matter Monte Carlo methods which contain elements from
shell model Monte Carlo methods and from numerical simulations of the Hubbard
model. We show that energy and basic saturation properties of nuclear matter
can be reproduced. Evidence of a first-order phase transition from an
uncorrelated Fermi gas to a clustered system is observed by computing
mechanical and thermodynamical quantities such as compressibility, heat
capacity, entropy and grand potential. We compare symmetry energy and first
sound velocities with literature and find reasonable agreement.


title: Charge exchange in relativistic heavy ion collisions

abstract:
  Elastic charge-exchange in relativistic heavy ion collisions is responsible
for the non-disruptive change of the charge state of the nuclei. We show that
it can be reliably calculated within the eikonal approximation for the reaction
part. The formalism is applied to the charge-pickup cross sections of 158
GeV/nucleon Pb projectiles on several targets. The relative contributions of
pion- and rho-exchange are determined, using a single-particle model for the
internal structure of the nuclei. The calculated cross sections are
non-negligible for heavy targets. It is shown that these cross sections can be
useful to obtain information on the Gamow-Teller transition strengths of the
nuclei.


title:
Determination of the Pion-Nucleon Coupling Constant in the VPI/GW
  Pion-Nucleon Elastic Scattering Partial Wave and Dispersion Relation Analyis

abstract:
  Our extraction of the pion-nucleon coupling constant from \pi p elastic
scattering data is outlined. A partial wave analysis (T_{\pi} < 2100 MeV) is
performed simultaneously with a fixed-t dispersion relation analysis (T_{\pi} <
800 MeV). The \pi NN coupling constant g^2/4\pi is searched to find the best
fit. The result 13.73 \pm 0.01 \pm 0.07 (first error statistical, second
systematic) is found to be insensitive to database changes and Coulomb barrier
corrections. This value satisfies important elements of low energy QCD like the
Goldberger-Treiman discrepancy, the Dashen-Weinstein sum rule, and chiral
perturbation theory predictions of threshold pion photoproduction.


title:
Coulomb wave function corrections for n-particle Bose-Einstein
  correlations

abstract:
  The effect of multi-particle Coulomb final state interactions on higher-order
intensity correlations is determined in general, based on a scattering wave
function which is solution of the n-body Coulomb Schr\"odinger equation in (a
large part of) the asymptotic region of n-body configuration space. In
particular, we study Coulomb effects on the n-particle Bose-Einstein
correlation functions of similarly charged particles and remove a systematic
error as big as 100% from higher-order multi-particle Bose-Einstein correlation
functions.


title:
Particle-Number Reprojection in the Shell Model Monte Carlo Method:
  Application to Nuclear Level Densities

abstract:
  We introduce a particle-number reprojection method in the shell model Monte
Carlo that enables the calculation of observables for a series of nuclei using
a Monte Carlo sampling for a single nucleus. The method is used to calculate
nuclear level densities in the complete $(pf+g_{9/2})$-shell using a good-sign
Hamiltonian. Level densities of odd-A and odd-odd nuclei are reliably extracted
despite an additional sign problem. Both the mass and the $T_z$ dependence of
the experimental level densities are well described without any adjustable
parameters. The single-particle level density parameter is found to vary
smoothly with mass. The odd-even staggering observed in the calculated
backshift parameter follows the experimental data more closely than do
empirical formulae.


title: The Role of $\Delta(1232)$ in Two-pion Exchange Three-nucleon Potential

abstract:
  In this paper we have studied the two-pion exchange three-nucleon potential
$(2\pi E-3NP)$ using an approximate $SU(2) \times SU(2)$ chiral symmetry of the
strong interaction. The off-shell pion-nucleon scattering amplitudes obtained
from the Weinberg Lagangian are supplemented with contributions from the
well-known $\sigma$-term and the $\Delta(1232)$ exchange. It is the role of the
$\Delta$-resonance in $2\pi E-3NP$, which we have investigated in detail in the
framework of the Lagrangian field theory. The $\Delta$-contribution is quite
appreciable and, more significantly, it is dependent on a parameter Z which is
arbitrary but has the empirical bounds $|Z| \leq 1/2$. We find that the
$\Delta$-contribution to the important parameters of the $2\pi E-3NP$ depends
on the choice of a value for Z, although the correction to the binding energy
of triton is not expected to be very sensitive to the variation of Z within its
bounds.


title:
Chiral $3\pi$-exchange NN-potentials: results for representation
  invariant classes of diagrams

abstract:
  We calculate in (two-loop) chiral perturbation theory the local NN-potentials
generated by certain classes of three-pion exchange diagrams. We stress that
the chiral $3\pi NN$-contact vertex depends on the particular choice of the
interpolating pion-field and therefore one has to consider representation
invariant classes of diagrams by supplementing graphs involving the chiral
$4\pi$-vertex. We find that the resulting isovector spin-spin and tensor
NN-potentials are negligibly small for $r\geq 0.8$ fm. One can conclude that
the effects of uncorrelated chiral $3\pi$-exchange in the NN-interaction are
very small and therefore of no practical relevance.


title: Helicity Formalism for NN Scattering without Partial Wave Decomposition

abstract:
  At intermediate energies it appears advantageous to work without partial wave
decomposition and use directly the momentum vectors. We derived a finite set of
coupled Lippmann-Schwinger equations using helicities. They can be used for any
type of realistic NN forces, which are given in operator form. As an example we
have chosen the Bonn OBEPR NN potential.


title: Shell Corrections of Superheavy Nuclei in Self-Consistent Calculations

abstract:
  Shell corrections to the nuclear binding energy as a measure of shell effects
in superheavy nuclei are studied within the self-consistent Skyrme-Hartree-Fock
and Relativistic Mean-Field theories. Due to the presence of low-lying proton
continuum resulting in a free particle gas, special attention is paid to the
treatment of single-particle level density. To cure the pathological behavior
of shell correction around the particle threshold, the method based on the
Green's function approach has been adopted. It is demonstrated that for the
vast majority of Skyrme interactions commonly employed in nuclear structure
calculations, the strongest shell stabilization appears for Z=124, and 126, and
for N=184. On the other hand, in the relativistic approaches the strongest
spherical shell effect appears systematically for Z=120 and N=172. This
difference has probably its roots in the spin-orbit potential. We have also
shown that, in contrast to shell corrections which are fairly independent on
the force, macroscopic energies extracted from self-consistent calculations
strongly depend on the actual force parametrisation used. That is, the A and Z
dependence of mass surface when extrapolating to unknown superheavy nuclei is
prone to significant theoretical uncertainties.


title: (p,\pi^+-) correlations in central heavy-ion collisions at 1-2 AGeV

abstract:
  The proton - charged pion correlated emission is studied in the reactions Au
(1.06 AGeV) + Au, Ni (1.06 and 1.93 AGeV) + Ni and Ni (1.97 AGeV) + Cu within
the BUU approach. The associated invariant mass distributions are shifted to
smaller energies with respect to the free $\Delta(1232)$ mass distribution due
to kinematical reasons. We find that the existing and partly conflicting
experimental data do not allow to draw definite conclusions on the in-medium
modification of the $\Delta(1232)$.


title: Perturbative Effective Field Theory at Finite Density

abstract:
  An accurate description of nuclear matter starting from free-space nuclear
forces has been an elusive goal. The complexity of the system makes
approximations inevitable, so the challenge is to find a consistent truncation
scheme with controlled errors. Nonperturbative effective field theories could
be well suited for the task. Perturbative matching in a model calculation is
used to explore some of the issues encountered in extending effective field
theory techniques to many-body calculations.


title:
Deuteron Magnetic and Quadrupole Moments with a Poincar\'e Covariant
  Current Operator in the Front-Form Dynamics

abstract:
  The deuteron magnetic and quadrupole moments are unambiguosly determined
within the front-form Hamiltonian dynamics, by using a new current operator
which fulfills Poincar\'e, parity and time reversal covariance, together with
hermiticity and the continuity equation. For both quantities the usual
disagreement between theoretical and experimental results is largely removed.


title:
Nuclear Matter with Quark-Meson Coupling I: Comparison of Nontopological
  Soliton Models

abstract:
  A system of nontopological solitons interacting through scalar and vector
meson exchange is used to model nuclear matter. The models studied are of the
Friedberg-Lee type, which exhibit dynamical bag formation due to the coupling
of quarks to a scalar composite gluon field. It is shown that the chiral
chromodielectric model gives the best fit to the empirical data. The presence
of the scalar meson guarantees saturation and an increase of the proton charge
radius with nuclear density consistent with the EMC effect.


title: Nuclear Matter with Quark-Meson Coupling II: Modeling a Soliton Liquid

abstract:
  We study in further detail a nontopological soliton model with coupling
between quarks and mesons selected as promising in the previous work. Here we
go beyond the Wigner-Seitz approximation by introducing the disorder necessary
to reproduce the liquid state. We study nuclear matter, with particular
interest in the transition to a quark-gluon plasma. The model studied is a
variation of the chiral chromodielectric model of Fai, Perry and Wilets, where
explicit coupling to a scalar meson field is introduced.


title:
Semiclassical transport of hadrons with dynamical spectral functions in
  A+A collisions at SIS/AGS energies

abstract:
  The transport of hadrons with dynamical spectral functions A_h(X,\vec{P},M^2)
is studied for nucleus-nucleus collisions at SIS and AGS energies in comparison
to the conventional quasi-particle limit and the available experimental data
within the recently developed off-shell HSD transport approach. Similar to
reactions at GANIL energies the off-shell effects show up in high momentum
tails of the particle spectra, however, at SIS and AGS energies these
modifications are found to be less pronounced than at lower energies due to the
high lying excitations of the nucleons in the collision zone.


title:
Infinite Nuclear Matter on the Light Front: A Modern Approach to
  Brueckner Theory

abstract:
  Understanding an important class of experiments requires that light-front
dynamics and related light cone variables k^+ and k_perp be used. If one uses
k^+ as a momentum variable, the corresponding canonical spatial variable is
x^-=x^0-x^3 and the time variable is x^0+x^3. This is the light front (LF)
approach of Dirac. A relativistic light front formulation of nuclear dynamics
is developed and applied to treating infinite nuclear matter in a method which
includes the corelations of pairs of nculeons. This is light front Brueckner
theory.


title: Isoscalar compression modes in relativistic random phase approximation

abstract:
  A fully consistent relativistic RPA calculation is performed for the monopole
and dipole compression modes in nuclei. The emphasis is put on the effects of
Dirac sea states which are generally neglected in relativistic RPA
calculations. It is found that these effects can be quite important for the
isoscalar monopole mode. The main contributions from the pairs of Fermi to
Dirac sea states are through the exchange of the scalar meson, while the vector
mesons play a negligible role. Numerical results of relativistic RPA are
checked with the constrained relativistic mean field model in the monopole
case. A good agreement beteween monopole energies calculated in RRPA and in
time-dependent relativistic mean field approach is achieved. For the monopole
compression mode, a comparison of experimental and calculated energies gives a
value of 250 $\sim$ 270 MeV for the nuclear matter incompressibility. A large
discrepancy remains between theory and experiment in the case of the dipole
compression mode.


title:
Excitation of multiple giant dipole resonances: from spherical to
  deformed nuclei

abstract:
  The effect of deformation on the excitation of multiple giant dipole
resonances is studied. Analytical expressions are derived in the framework of
the interacting boson model for the energies and E1 properties of giant dipole
resonances in spherical and deformed nuclei, and a numerical treatment of
transitional nuclei is proposed. Coulomb-excitation cross sections are
calculated in $^{238}$U and in the samarium isotopes.


title: Color superconductivity in weak coupling

abstract:
  We derive perturbatively the gap equations for a color-superconducting
condensate with total spin J=0 in dense QCD. At zero temperature, we confirm
the results of Son for the dependence of the condensate on the coupling
constant, and compute the prefactor to leading logarithmic accuracy. At nonzero
temperature, we find that to leading order in weak coupling, the temperature
dependence of the condensate is identical to that in BCS-like theories. The
condensates for total spin J=1 are classified; to leading logarithmic accuracy
these condensates are of the same order as those of spin J=0.


title: Matter-induced hadronic processes

abstract:
  Two examples of ``exotic'' phenomena which become possible and important in
the presence of nuclear matter are discussed: omega -> pi pi decay, and
rho-omega mixing. Significance of these processes for the low-mass dilepton
production in relativistic heavy-ion collisions is indicated.


title: Deuteron Formation in Heavy Ion Collisions within the Faddeev Approach

abstract:
  We address the formation of correlations in a general nonequilibrium
situation. As an example we calculate the formation of light composite
particles in a heavy ion collision. In particular we study the formation of
deuterons via three-body reactions in some detail. To calculate the relevant
reaction rates we solve the Faddeev equation which is consistently modified to
include the self energy corrections and Pauli blocking factors due to
surrounding nucleons. We find that the time scales of the reaction as well as
the number of emitted deuterons change as medium dependent rates are used in
the calculation.


title: Correlations and realistic interactions in doubly closed shell nuclei

abstract:
  We review the latest variational calculations of the ground state properties
of doubly closed shell nuclei, from $^{12}$C to $^{208}$Pb, with semirealistic
and realistic two- and three-nucleon interactions. The studies are carried on
within the framework of the correlated basis function theory and integral
equations technique, with state dependent correlations having central and
tensor components. We report results for the ground state energy, one- and
two-body densities and static structure functions. For $^{16}$O and $^{40}$Ca
we use modern interactions and find that the accuracy of the method is
comparable to that attained in nuclear matter with similar hamiltonians, giving
nuclei underbound by $\sim$2 MeV/A. The computed Coulomb sums are in complete
agreement with the latest analysis of the experimental data.


title: $N\Omega$ and $\Delta\Omega$ dibaryons in SU(3) chiral quark model

abstract:
  The binding energy of the six quark system with strangeness s=-3 is
investigated under the chiral SU(3) constituent quark model in the framework of
$RGM$. The calculations of the single $N\Omega$ channel with spin S=2 and the
single $\Delta\Omega$ channel with spin S=3 are performed. The results show
that both systems could be dibaryons and the interaction induced by the chiral
field plays a very important role on forming bound states in the systems
considered.
  The phase shifts and scattering lengths in corresponding channels are also
given.


title:
Finite size effects and the order of a phase transition in fragmenting
  nuclear systems

abstract:
  We discuss the implications of finite size effects on the determination of
the order of a phase transition which may occur in infinite systems. We
introduce a specific model to which we apply different tests. They are aimed to
characterise the smoothed transition observed in a finite system. We show that
the microcanonical ensemble may be a useful framework for the determination of
the nature of such transitions.


title: State Dependent Effective Interaction for the Hyperspherical Formalism

abstract:
  The method of effective interaction, traditionally used in the framework of
an harmonic oscillator basis, is applied to the hyperspherical formalism of
few-body nuclei (A=3-6). The separation of the hyperradial part leads to a
state dependent effective potential. Undesirable features of the harmonic
oscillator approach associated with the introduction of a spurious confining
potential are avoided. It is shown that with the present method one obtains an
enormous improvement of the convergence of the hyperspherical harmonics series
in calculating ground state properties, excitation energies and transitions to
continuum states.


title:
Numerical renormalization using dimensional regularization: a simple
  test case in the Lippmann-Schwinger equation

abstract:
  Dimensional regularization is applied to the Lippmann-Schwinger equation for
a separable potential which gives rise to logarithmic singularities in the Born
series. For this potential a subtraction at a fixed energy can be used to
renormalize the amplitude and produce a finite solution to the integral
equation for all energies. This can be done either algebraically or
numerically. In the latter case dimensional regularization can be implemented
by solving the integral equation in a lower number of dimensions, fixing the
potential strength, and computing the phase shifts, while taking the limit as
the number of dimensions approaches three. We demonstrate that these steps can
be carried out in a numerically stable way, and show that the results thereby
obtained agree with those found when the renormalization is performed
algebraically to four significant figures.


title:
Nuclear forces from chiral Lagrangians using the method of unitary
  transformation II: The two-nucleon system

abstract:
  We employ the chiral nucleon-nucleon potential derived in ref.[1] to study
bound and scattering states in the two-nucleon system. At next-to-leading
order, this potential is the sum of renormalized one-pion and two-pion exchange
and contact interactions. At next-to-next-to-leading order, we have additional
chiral two-pion exchange with low-energy constants determined from pion-nucleon
scattering. Alternatively, we consider the \Delta(1232) as an explicit degree
of freedom in the effective field theory. The nine parameters related to the
contact interactions can be determined by a fit to the np S- and P-waves and
the mixing parameter \epsilon_1 for laboratory energies below 100 MeV. The
predicted phase shifts and mixing parameters for higher energies and higher
angular momenta are mostly well described for energies below 300 MeV. The
S-waves are described as precisely as in modern phenomenological potentials. We
find a good description of the deuteron properties.


title:
Inclusive electron scattering from nuclei: y-scaling and final state
  interaction

abstract:
  The recent TJLAB experimental data on inclusive electron scattering at high
momentum transfer from complex nuclei are analyzed in terms of y-scaling,
taking into account the final state interaction (FSI) of the struck, off-shell
nucleon. It is shown that at large negative values of y (x>1), the Q^2
dependence of the FSI is mostly driven by the elastic nucleon-nucleon cross
section, and that, as a result, the scaling function decreases with Q^2, in
agreement with experimental data.


title: Possible $\Delta\Delta$ dibaryons in the quark cluster model

abstract:
  In the framework of RGM, the binding energy of one channel
$\Delta\Delta_{(3,0)}$($d^*$) and $\Delta\Delta_{(0,3)}$ are studied in the
chiral SU(3) quark cluster model. It is shown that the binding energies of the
systems are a few tens of MeV. The behavior of the chiral field is also
investigated by comparing the results with those in the SU(2) and the extended
SU(2) chiral quark models. It is found that the symmetry property of the
$\Delta\Delta$ system makes the contribution of the relative kinetic energy
operator between two clusters attractive. This is very beneficial for forming
the bound dibaryon. Meanwhile the chiral-quark field coupling also plays a very
important role on binding. The S-wave phase shifts and the corresponding
scattering lengths of the systems are also given.


title: Final-State Interaction in Electron Scattering by Polarized Nuclei

abstract:
  The cross section for the reaction $^{39}\vec{{\rm K}}(e,e'p)^{38}$Ar is
computed, and the dependence of the FSI on the initial polarization angles of
the nucleus $^{39}$K is analyzed. The results are explained in a semi-classical
picture of the reaction. This procedure allows us to find the best initial
kinematical conditions for minimizing the FSI.


title:
Application of the extended P+QQ force model to $N \approx Z$ fp shell
  nuclei

abstract:
  To study collective motion, the extended pairing plus $QQ$ force model
proposed recently is applied to $A$=46, 48 and 50 nuclei in the $fp$ shell
region.
  Exact shell model calculations in the truncated model space
  $(f_{7/2},p_{3/2},p_{1/2})$ prove the usefulness of the interaction.
  The simple model with the pairing plus quadrupole pairing plus $QQ$ force and
$J$-independent isoscalar proton-neutron force reproduces unexpectedly well
observed binding energies, energy levels of collective (yrast) states and
reduced $E2$ transition probabilities in $^{46}$Ti, $^{46}$V, $^{48}$V,
$^{48}$Cr, $^{50}$Cr and $^{50}$Mn.
  The correspondence between theory and experiment is almost comparable to that
attained by the full $fp$ shell model calculations with realistic effective
interactions. Some predictions are made for energy levels and variations of
$B(E2)$ in the yrast bands, in these nuclei. Characteristics of the interaction
are investigated by comparing with the realistic effective interactions.


title: The Pion Electroproduction in the $\Delta$(1232) region region

abstract:
  The amplitudes of the pion electroproduction from the nucleon are derived up
to third order in the chiral effective theory including explicit $\Delta$(1232)
>. The Q^2 evolutions of weighted integrals of amplitudes are presented.


title: Ternary configuration in the framework of inverse mean-field method

abstract:
  A static scission configuration in cold ternary fission has been considered
in the framework of mean field approach. The inverse scattering method is
applied to solve single-particle Schroedinger equation, instead of constrained
selfconsistent Hartree-Fock equations. It is shown, that it is possible to
simulate one-dimensional three-center system via inverse scattering method in
the approximation of reflectless single-particle potentials.


title: Electromagnetic response of light nuclei

abstract:
  We show examples of neutron capture, photo dissociation and Coulomb
dissociation processes, relevant for studying nuclear structure properties of
some light nuclei. In the case of the neutron capture, we show how interference
effects among the direct and resonance processes can be accounted for. The same
interference effect is shown to play an important role in the photo
dissociation of 9Be, for excitation energies just above the neutron emission
threshold. Finally, the Coulomb dissociation of radioactive projectiles is
shown to provides basic structure information on neutron rich exotic systems.
The example of the 19C halo structure is shown.


title: Chiral NN interaction in nuclear matter

abstract:
  The effective field theory of NN interactions in nuclear matter is
considered. Due to the Pauli principle the effective NN amplitude is not
affected by the shallow bound states. We show that the next-to-leading order
terms in the chiral expansion of the effective NN potential can be interpreted
as corrections so the expansion is systematic. The value of potential energy
per particle is calculated and some issues concerning the chiral effective
theory of nuclear matter are outlined.


title: Memory effects and thermodynamics in strong field plasmas

abstract:
  We study the evolution of a strong field plasma using a quantum Vlasov
equation with a non-Markovian source term and a simple collision term, and
calculate the time dependence of the energy- and number-density, and the
temperature. The evolution of a plasma produced with RHIC-like initial
conditions is well described by a low density approximation to the source term.
However, non-Markovian aspects should be retained to obtain an accurate
description of the early stages of an LHC-like plasma.


title: Chiral quark-soliton model in the Wigner-Seitz approximation

abstract:
  In this paper we study the modification of the properties of the nucleon in
the nucleus within the quark-soliton model. This is a covariant, dynamical
model, which provides a non-linear representation of the spontaneously broken
SU(2)_L X SU(2)_R symmetry of QCD. The effects of the nuclear medium are
accounted for by using the Wigner-Seitz approximation and therefore reducing
the complex many-body problem to a simpler single-particle problem. We find a
minimum in the binding energy at finite density, a change in the isoscalar
nucleon radius and a reduction of the in-medium pion decay constant. The latter
is consistent with a partial restoration of chiral symmetry at finite density,
which is predicted by other models.


title: Nucleon-Nucleon interaction in a chiral constituent quark model

abstract:
  We study the nucleon-nucleon (NN) problem as a six-quark system in a
nonrelativistic chiral constituent quark model where the Hamiltonian contains a
linear confinement and a pseudoscalar meson (Goldstone boson) exchange
interaction between the quarks. This interaction has a long range Yukawa-type
part, depending on the mass of the exchanged meson and a short range part,
mainly responsible for the good description of the baryon spectra. We calculate
the NN potential in the adiabatic approximation as a function of Z, the
separation distance between the centres of the two three-quark clusters. The
orbital part of the six-quark states is constructed either from the usual
cluster model states or from molecular orbital single particle states. The
latter are more realistic, having proper axially and reflectionally symmetries.
In both cases the potential presents an important hard core at short distances,
explained through the dominance of the [51]{FS} configuration. However in the
molecular orbital basis the core is less repulsive, as a consequence of the
fact that this basis gives a better upper bound for the energy of the six-quark
system. We calculate the potential for the 3S1 and 3S0 channels with two
different parametrizations. We find a small (few MeV) attractive pocket for one
of these parametrizations. A middle range attraction is simulated by the
addition of a sigma-meson exchange interaction between quarks, of a form
similar to that of the pseudoscalar meson exchange. The present study is an
intermediate, useful step towards dynamical calculations based on the
resonating group method.


title:
Strangeness-changing response functions:an alternative approach to
  hypernuclear structure

abstract:
  We study strangeness-changing response functions as an alternative
description of hypernuclear structure. Hypernuclear states are treated in the
same manner as any other conventional nuclear excitation that emerges from the
response of the nuclear ground state to an external probe. The nuclear response
is calculated using a random-phase approximation to an effective relativistic
mean-field model that reproduces bulk properties of normal nuclei. The relevant
meson-baryon vertices are constrained by imposing SU(3)-flavor symmetry, while
the residual hyperon-particle - nucleon-hole interaction is assumed to be
mediated by the two lightest S = -1 mesons: the pseudoscalar kaon and its
vector partner the K*(892). We use this model to analyze the spectra of oxygen
and calcium hypernuclei.


title:
Sum rules regarding the sign problem in Monte Carlo shell model
  calculations

abstract:
  The Monte Carlo shell model is a powerful technique for computational nuclear
structure. Only a certain class of nuclear interactions, however, such as
pairing and quadrupole, are free of the numerical noise known as the sign
problem.This paper presents sum rules that relate the sign problem to the J=0
pairing matrix elements, thus illuminating the extrapolation procedure
routinely used for realistic shell-model interactions.


title: A simple model for the microscopic effective pairing interaction

abstract:
  The microscopic effective pairing interaction in the $^1S_0$-channel is
investigated for two different values of the chemical potential $\mu$ starting
from the separable form of the Paris NN-potential. It is shown that, within a
high accuracy, this effective interaction can be approximated by the off-shell
free T-matrix taken at the negative energy $E=2\mu$.


title: Form Factors of Baryons in a Confining and Covariant Diquark-Quark Model

abstract:
  We treat baryons as bound states of scalar or axialvector diquarks and a
constituent quark which interact through quark exchange. This description
results as an approximation to the relativistic Faddeev equation for three
quarks which yields an effective Bethe-Salpeter equation. Octet and decuplet
masses and fully four-dimensional wave functions have been computed for two
cases: assuming an essentially pointlike diquark on the one hand, and a diquark
with internal structure on the other hand. Whereas the differences in the mass
spectrum are fairly small, the nucleon electromagnetic form factors are greatly
improved assuming a diquark with structure. First calculations to the
pion-nucleon form factor also suggest improvements.


title: NNLO Corrections to Nucleon-Nucleon Scattering and Perturbative Pions

abstract:
  The 1S0, 3S1, and 3D1 nucleon-nucleon scattering phase shifts are calculated
at next-to-next-to-leading order (NNLO) in an effective field theory.
Predictions for the 1P1, 3P0, 3P1, 3P2, 1D2, 3D2, and 3D3 phase shifts at this
order are also compared with data. The calculations treat pions perturbatively
and include the NNLO contributions from order $Q_r^3$ and $Q_r^4$ radiation
pion graphs. In the 3S1, 3D1, 3P0, and 3P2 channels we find large disagreement
with the Nijmegen partial wave analysis at NNLO. These spin triplet channels
have large corrections from graphs with two potential pion exchange which do
not vanish in the chiral limit. We compare our results to calculations within
the Weinberg approach, and find that in some spin triplet channels the
summation of potential pion diagrams seems to be necessary to reproduce the
observed phase shifts. In the spin singlet channels the nonperturbative
treatment of potential pions does not afford a significant improvement over the
perturbative approach.


title:
Polarization degrees of freedom in two-nucleon knockout from finite
  nuclei

abstract:
  Polarization observables for the A(e,e'NN) and A(\gamma,NN) reactions are a
powerful tool to study nucleon-nucleon correlations in the nuclear medium. In
this paper, model calculations for the ^{4}He(e,e'pp),
^{16}O(\vec{e},e'\vec{p}p), ^{16}O(\vec{e},e' \vec{p}n) and
^{12}C(\vec{\gamma},\vec{p}N) reactions are presented. The sensitivity of the
differential cross sections and polarization observables to central and
spin-dependent nucleon-nucleon correlations is discussed.


title: Few-Body States in Fermi-Systems and Condensation Phenomena

abstract:
  Residual interactions in many particle systems lead to strong correlations. A
multitude of spectacular phenomenae in many particle systems are connected to
correlation effects in such systems, e.g. pairing, superconductivity,
superfluidity, Bose-Einstein condensation etc. Here we focus on few-body bound
states in a many-body surrounding.


title: Analytic solution for relativistic transverse flow at the softest point

abstract:
  We obtain an extension of Bjorken's 1+1 dimensional scaling relativistic flow
solution to relativistic transverse velocities with cylindrical symmetry in 1+3
dimensions at constant, homogeneous pressure (vanishing sound velocity). This
can be the situation during a first order phase transition converting quark
matter into hadron matter in relativistic heavy ion collisions.


title: Antiproton annihilation on light nuclei at very low energies

abstract:
  The recent experimental data obtained by the OBELIX group on $\bar{p}$D and
$\bar{p}^4$He total annihilation cross sections are analyzed. The combined
analysis of these data with existing antiprotonic atom data allows, for the
first time, the imaginary parts of the S-wave scattering lengths for the two
nuclei to be extracted. The obtained values are: $Im a^{sc}_0 = [- 0.62 \pm
0.02 ({stat}) \pm 0.04 ({sys})] fm$ for $\bar{p}$D and $Im a^{sc}_0 = [-
0.36\pm 0.03({stat})^{+0.19}_{-0.11}({sys})] fm$ for $\bar{p}^4$He. This
analysis indicates an unexpected behaviour of the imaginary part of the
$\bar{p}$-nucleus S-wave scattering length as a function of the atomic weight
A: $|Im a^{sc}_0|$ ($\bar{p}$p) > $|Im a^{sc}_0|$ ($\bar{p}$D) > $|Im
a^{sc}_0|$ ($\bar{p}^4$He).


title:
Relationship between dinuclear systems and nuclei in highly deformed
  states

abstract:
  Potential energies, moments of inertia, quadrupole and octupole moments of
dinuclear systems are compared with the corresponding quantities of strongly
deformed nuclei. As dinuclear system we denote two touching nuclei (clusters).
It is found that the hyperdeformed states of nuclei are close to those of
nearly symmetric dinuclear systems, whereas the superdeformed states are
considered as states of asymmetric dinuclear systems. The superdeformed and
hyperdeformed states constructed from two touching clusters have large octupole
deformations. The experimental measurement of octupole deformation of the
highly deformed nuclei can answer whether these nuclei have cluster
configurations as described by the dinuclear model.


title:
Dynamical restriction for a growing neck due to mass parameters in a
  dinuclear system

abstract:
  Mass parameters for collective variables of a dinuclear system and strongly
deformed mononucleus are microscopically formulated with the linear response
theory making use of the width of single particle states and the
fluctuation-dissipation theorem. For the relative motion of the nuclei and for
the degree of freedom describing the neck between the nuclei, we calculate mass
parameters with basis states of the adiabatic and diabatic two-center shell
model. Microscopical mass parameters are found larger than the ones obtained
with the hydrodynamical model and give a strong hindrance for a melting of the
dinuclear system along the internuclear distance into a compound system.
Therefore, the dinuclear system lives a long time enough comparable to the
reaction time for fusion by nucleon transfer. Consequences of this effect for
the complete fusion process are discussed.


title: QED-QCD Interference Effect on the Charge Dependent N-N Interaction

abstract:
  The charge symmetry breaking and charge independence breaking N-N ^1S_0
scattering length differences, Delta a_{CSB} and Delta a_{CIB}, are calculated
by a resonating group method with a quark cluster model. By adding the QED-QCD
interference effect to the quark mass difference and the electromagnetic
interaction, the Delta a_{CSB} and Delta a_{CIB} values can be reproduced with
model parameters constrained by the hadron isomultiplet mass splitting.


title: Dinuclear concept - cluster model of fusion

abstract:
  The synthesis of superheavy elements is analysed within the dinuclear system
concept of compound nucleus formation. The perspectives for using radioactive
beams in complete fusion reactions are discussed.


title:
Orthogonality Effects in Relativistic Models of Nucleon Knockout
  Reactions

abstract:
  We study the effect of wave function orthogonality in the relativistic
treatment of the nucleon removal reactions (gamma, p) and (e, e' p). The
continuum wave function describing the outgoing nucleon is made orthogonal to
the relevant bound states using the Gram-Schmidt procedure. This procedure has
the advantage of preserving the asymptotic character of the continuum wave
function and hence the elastic observables are unaffected. The orthogonality
effects are found to be negligible for (e, e' p) reactions for missing momenta
up to 700 MeV/c. This holds true for both parallel and perpendicular
kinematics. By contrast the orthogonalization of the wave functions appears to
have a more pronounced effect in the case of (gamma, p) reactions. We find that
the orthogonality effect can be significant in this case particularly for large
angles. Polarization of the outgoing protons and photon asymmetry show more
sensitivity than the cross sections. If the orthogonality condition is imposed
solely on this one hole state the effects are usually smaller.


title: Melting or nucleon transfer in fusion of heavy nuclei?

abstract:
  The time-dependent transition between a diabatic interaction potential in the
entrance channel and an adiabatic potential during the fusion process is
investigated within the two-center shell model. A large hindrance is obtained
for the motion to smaller elongations of near symmetric dinuclear systems. The
comparison of the calculated energy thresholds for the complete fusion in
different relevant collective variables shows that the dinuclear system prefers
to evolve in the mass asymmetry coordinate by nucleon transfer to the compound
nucleus.


title: Can shadowing mimic the QCD phase transition?

abstract:
  The directed flow of protons is studied in the quark-gluon string model as a
function of the impact parameter for S+S and Pb+Pb reactions at 160 AGeV/c. A
significant reduction of the directed flow in midrapidity range, which can lead
to the development of the antiflow, is found due to the absorption of early
emitted particles by massive spectators (shadowing effect). This effect can
mimic the formation of the quark-gluon plasma (QGP). However, in the absorption
scenario the antiflow is stronger for the system of light colliding nuclei than
for the heavy ones, while in the case of the plasma creation the effect should
be opposite.


title: Two Lectures on Small x Physics and High Gluon Density

abstract:
  In these lectures, I shall discuss small x physics and the consequences of
the high gluon density which arises as x decreases. I argue that an
understanding of this problem would lead to knowledge of the high energy
asymptotics of hadronic processes. The high gluon density should allow a first
principles computation of these asymptotics from QCD. This physics might be
experimentally probed in heavy ion colliders or in high energy electron-nuclear
collisions


title: Density dependent hadron field theory for hypernuclei

abstract:
  The Density Dependent Relativistic Hadron Field (DDRH) theory, previously
introduced and applied to isospin nuclei, is extended to hypernuclei by
including the octet hyperons. Infinite matter Dirac-Brueckner theory for octet
baryons and the derivation of in-medium DDRH baryon-meson vertices is
discussed. From the properties of Dirac-Brueckner interactions it is found that
hyperon and nucleon self-energies and vertices are related by the ratios of
free space coupling constants. This leads to simple scaling laws for the
in-medium hyperon and nucleon vertices. The model is applied in relativistic
DDRH mean-field calculations to singl$\Lambda nuclei. Free space N-Lambda
T-matrix results are used for the scalar vertex. As the only free parameter the
hyperon vector vertex scaling factor is adjusted to a selected set of
hypernuclear data. Spectroscopic data of single Lambda hypernuclei over the
full mass range are well described. The reduced Lambda spin-orbit splitting is
reproduced and found to be related closely the medium dependence of scalar and
vector interactions.


title:
Comparison of Strangeness Production between A+A and p+p Reactions from
  2 to 160 AGeV

abstract:
  The measured K$^+/\pi^+$ ratios from heavy-ion reactions are compared with
the K$^+/\pi^+$ ratios from p+p reactions over the energy range 2-160 AGeV. The
K/$\pi$ enhancement in heavy-ion reactions is largest at the lower energies,
consistent with strangeness production in secondary scattering becoming
relatively more important than initial collisions near the kaon production
threshold. The enhancement decreases steadily from 4 to 160 AGeV, suggesting
that the same enhancement mechanism of hadronic rescattering and decay of
strings may be applicable over this full energy range. Based on existing data,
the mid-rapidity K$^+/\pi^+$ ratio is predicted to be $0.27\pm0.05$ for the
forthcoming Pb+Pb reactions at 40 AGeV/c.


title:
Relativistic Quark Spin Coupling Effects in the Nucleon Electromagnetic
  Form Factors

abstract:
  We investigate the effect of different forms of relativistic spin coupling of
constituent quarks in the nucleon electromagnetic form factors. The
four-dimensional integrations in the two-loop Feynman diagram are reduced to
the null-plane, such that the light-front wave function is introduced in the
computation of the form factors. The neutron charge form factor is very
sensitive to different choices of spin coupling schemes, once its magnetic
moment is fitted to the experimental value. The scalar coupling between two
quarks is preferred by the neutron data, when a reasonable fit of the proton
magnetic momentum is found.


title: Color Superconductivity

abstract:
  We discuss recent results on color superconductivity in QCD at large chemical
potential.


title:
Precision Calculation of n+p->d+gamma Cross Section for Big-Bang
  Nucleosynthesis

abstract:
  An effective field theory calculation of the n+p->d+gamma cross section
accurate to 1% for center of mass energy E up to ~1 MeV is presented. At these
energies, which are relevant for big-bang nucleosynthesis, isovector magnetic
transitions M1 and isovector electric transitions E1 give the dominant
contributions. The M1 amplitude is calculated up to next-to-next-to-leading
order (NNLO) and the contribution from the associated four-nucleon-one-photon
operator is determined from the cold neutron capture rate. The E1 amplitude is
calculated up to NNNNLO. The four-nucleon-one-photon operator contribution to
E1 is determined from the related deuteron photodisintegration reaction
gamma+d->n+p.


title: Parameter Counting in Relativistic Mean-Field Models

abstract:
  Power counting is applied to relativistic mean-field energy functionals to
estimate contributions to the energy from individual terms. New estimates for
isovector, tensor, and gradient terms in finite nuclei are shown to be
consistent with direct, high-quality fits. The estimates establish a hierarchy
of model parameters and identify how many parameters are well constrained by
bulk nuclear observables. We conclude that four (possibly five) isoscalar,
non-gradient parameters, one gradient parameter, and one isovector parameter
are well determined by the usual bulk nuclear observables.


title: Kaon Photoproduction in a Confining and Covariant Diquark Model

abstract:
  Baryons are modeled as bound states of scalar or axialvector diquarks and a
constituent quark which interact through quark exchange. This description
results as an approximation to the relativistic Faddeev equation for three
quarks. The corresponding effective Bethe-Salpeter equation is solved, and
fully four-dimensional wave functions for both octet and decuplet baryons are
obtained. Confinement of quarks and diquarks is incorporated by modifying their
propagators. Results are given for kaon photoproduction which is one of the
applications currently under investigation in this model.


title: Double electron capture in 156Dy, 162Er and 168Yb

abstract:
  The double electron capture half-lives of 156Dy, 162Er and 168Yb are
evaluated using the pseudo SU(3) model, which describes ground and excited
bands as well as their B(E2) and B(M1) transition strengths in remarkable
agreement with experiment. The best candidate for experimental detection is the
decay 156Dy -> 156Gd, with tau{1/2} (0+{gs} --> 0+{gs}) = 2.74 E22 yrs and
tau{1/2} (0+{gs} --> 0+{1}) = 8.31 E24 yrs.


title: Weak axial exchange currents for the Bethe-Salpeter equation

abstract:
  We construct weak axial one-boson exchange currents for the Bethe-Salpeter
equation, starting from chiral Lagrangians of the
N-\Delta(1236)-pi-rho-a_1-omega system. The currents fulfil the Ward-Takahashi
identities and the matrix element of the full current between the two-body
solutions of the Bethe-Salpeter equation satisfies the PCAC constraint exactly.


title: Meson exchange models for Meson production

abstract:
  The production of mesons in nucleon-nucleon collisions is reviewed from the
viewpoint of the meson-exchange picture. In the first part various possible
production mechanisms and their relative importance are discussed. In addition,
general features of meson production are described.
  In the second part special emphasis is put on pion production. Implications
of chiral perturbation theory are discussed. Results based on a specific
meson-exchange model for pion production in nucleon-nucleon collisions are
presented. The model is utilized to calculate several spin-dependent
observables of the reactions $pp \to pp\pi^0$ and $pp \to pn\pi^+$ such as
spin-correlation parameters. This allows us to study the role of the Delta
resonance at close to threshold energies.
  The talk closes with a brief discussion of the production of $\phi$ mesons as
an example for the production of heavier mesons. A strategy is outlined that
allows to extract information on the structure of the nucleon from the reaction
$NN \to NN \phi$.