title:
N -> Delta DVCS, exclusive DIS processes and skewed quark distributions
  in large N_c limit

abstract:
  We evaluate the amplitude of Bethe-Heitler process: \gamma^* p -> \gamma
\Delta^+ -electron bremsstrahlung of photon accompanied by the excitation of
\Delta$ isobar. We show that this background is suppressed at small momentum
transfer squared t to a proton relative to that for \gamma^* p -> \gamma p and
\gamma^* p\to -> \Delta^+ - DVCS processes. From experimental point of view,
this means that N -> N and N -> \Delta skewed quark distributions (SQD's) might
be measurable at small momentum transfer. Several implications and applications
of the QCD factorization theorem for the processes \gamma_{L}^* + p -> h_f +h_s
are discussed where h_f - the particle produced along photon momentum $\vec q$
maybe either a meson or a baryon. We discuss also t dependence of DVCS and
exclusive meson production as the practical criteria to distinguish between
soft and hard regime. Basing on the large-N_c picture of the nucleon as a
soliton of the effective chiral Lagrangian we derive relations between N -> N
and N ->\Delta SQD's which can be used to estimate amplitude of N -> \Delta
DVCS .


title: Diffractive Structure Functions in the Model of the Stochastic Vacuum

abstract:
  We present a calculation for the diffractive structure functions $x_{\rm p}
F_{\rm T}^{D(3)}$ and $x_{\rm p} F_{\rm L}^{D(3)}$ at low values of $Q^2$ using
an eikonal approximation. The non-perturbative model of the stochastic QCD
vacuum is used to evaluate the interactions between the quarks (antiquarks) and
the color field. The diffractive final state contains only a quark-antiquark
pair. We show the behavior of the diffractive structure functions against
$\beta$ and $Q^2$.


title: Texture of a Four-Neutrino Mass Matrix

abstract:
  We propose a simple texture of the neutrino mass matrix with one sterile
neutrino along with the three standard ones. It gives maximal mixing angles for
$\nu_e \to \nu_S$ and $\nu_\mu \to \nu_\tau$ oscillations or vice versa. Thus
with only four parameters, this mass matrix can explain the solar neutrino
anomaly, atmospheric neutrino anomaly, LSND result and the hot dark matter of
the universe, while satisfying all other Laboratory constraints. Depending on
the choice of parameters, one can get the vacuum oscillation or the large angle
MSW solution of the solar neutrino anomaly.


title: Explicit Quark-Hadron Duality in 1+1 Dimensions

abstract:
  Explicit quark-hadron duality in the limit of heavy quark mass is studied
using the 't Hooft model, where both partonic and hadronic amplitudes may be
computed exactly. Results for weak decays of heavy mesons are presented for
both standard spectator decays, where the duality limit is convincingly
approached, and annihilation decays of the valence quark-antiquark pair, where
the approach to asymptotic duality is much less precise.


title: CP violation

abstract:
  The salient features of CP-violating interactions in the standard electroweak
theory and in a few of its popular extensions are discussed. Moreover a brief
overview is given on the status and prospects of searches for CP
non-conservation effects in low and high energy experiments.


title: Inclusive and Diffractive Structure Functions at Small x

abstract:
  In the semiclassical approach, inclusive and diffractive quark and gluon
distributions are expressed in terms of correlation functions of Wilson loops.
Each Wilson loop integrates the colour field strength in the area between the
trajectories of two fast partons penetrating the proton. We introduce a
specific model for averaging over the relevant colour field configurations.
Within this model, all parton distributions at some low scale Q_0^2 are given
in terms of three parameters. Inclusive and diffractive structure functions at
higher values of Q^2 are determined in a leading-order QCD analysis. In both
cases, the evolution is driven by a large gluon distribution. A satisfactory
description of the structure functions F_2(x,Q^2) and F_2^D(3)(xi,beta,Q^2) is
obtained. The observed rise of F_2^D(3) with xi is parametrized by a
non-perturbative logarithmic energy dependence, compatible with unitarity. In
our analysis, the observed rise of F_2 at small x is largely due to the same
effect.


title: Hard diffractive Photon-Proton Scattering at large t

abstract:
  We propose to test perturbative QCD in the Regge limit by means of
diffractive photon scattering $\gamma p \to \gamma X$ at large $t$ and very
high energies $W^2\gg |t|\gg \Lambda^2_{QCD}$. The helicity amplitudes of this
process were calculated using the Lipatov solution of the BFKL equation for
$t\neq 0$. We found that the perturbatively calculated cross section for this
process exceeds the cross section for $J/\Psi$ photoproduction assuming similar
kinematics.


title:
Neutralino properties in the light of a further indication of an annual
  modulation effect in WIMP direct search

abstract:
  We demonstrate that the further indication of a possible annual modulation
effect, singled out by the DAMA/NaI experiment for WIMP direct detection, is
widely compatible with an interpretation in terms of a relic neutralino as the
major component of dark matter in the Universe. We discuss the supersymmetric
features of this neutralino in the Minimal Supersymmetric extension of the
Standard Model (MSSM) and their implications for searches at accelerators.


title: Analytic Perturbative Approach to QCD

abstract:
  A technique called analytic perturbation theory, which respects the required
analytic properties, consistent with causality, is applied to the definition of
the running coupling in the timelike region, to the description of inclusive
$\tau$-decay, to deep-inelastic scattering sum rules, and to the investigation
of the renormalization scheme ambiguity. It is shown that in the region of a
few GeV the results are rather different from those obtained in the ordinary
perturbative description and are practically renormalization scheme
independent.


title:
Economical Doublet-Triplet Splitting and Strong Suppression of Proton
  Decay in SO(10)

abstract:
  We present a new approach to realizing the Dimopoulos-Wiczek mechanism for
doublet-triplet splitting in supersymmetric SO(10). The method can be used to
achieve strong suppression of proton decay in a straightforward manner and is
relatively economical; in particular the particle spectrum required for its
implementation is consistent with the constraints from string compactification
at Kac-Moody level two. We construct two examples of realistic models based on
this idea. These models have no unwanted flat directions and do not make use of
any nonrenormalizable operators to stabilize the vacuum thereby maintaining
coupling constant unification as a prediction. The first model is characterised
by a simple discrete symmetry that guarantees naturalness at the renormalizable
level while also eliminating all potentially dangerous R-parity violating
effects. The second model predicts the strong suppression of Higgsino mediated
proton decay. In both models the light MSSM doublets emerge from two different
{\bf 10}'s so that there is considerable flexibility in constructing realistic
fermion masses and CKM angles.


title:
Compatibility of the new DAMA/NaI data on an annual modulation effect in
  WIMP direct search with a relic neutralino in supergravity schemes

abstract:
  Recent results of the DAMA/NaI experiment for WIMP direct detection point to
a possible annual modulation effect in the detection rate. We show that these
results, when interpreted in terms of a relic neutralino, are compatible with
supergravity models. Together with the universal SUGRA scheme, we also consider
SUGRA models where the unification condition in the Higgs mass parameters at
GUT scale is relaxed.


title: Maximal Acceleration Limits on the Mass of the Higgs Boson

abstract:
  Caianiello's quantum geometrical model with maximal acceleration places the
upper limit $\mu\leq 719.5$ GeV on the mass of the Higgs boson. The model also
provides an equation linking the mass of the W boson to the Higgs mass $\mu$
and independent symmetry breaking and mass generating mechanisms. These may
further restrict the value of $\mu$.


title: Maximal Acceleration Corrections to the Lamb Shift of Muonic Hydrogen

abstract:
  The maximal acceleration corrections to the Lamb shift of muonic hydrogen are
calculated by using the relativistic Dirac wave functions. The correction for
the $2S-2P$ transition is $\sim 0.38$ meV and is higher than the accuracy of
present QED calculations and of the expected accuracy of experiments in
preparation.


title: Are Parton Distributions Positive?

abstract:
  We show that the naive positivity conditions on polarized parton
distributions which follow from their probabilistic interpretation in the naive
parton model are reproduced in perturbative QCD at the leading log level if the
quark and gluon distribution are defined in terms of physical processes. We
show how these conditions are modified at the next-to-leading level, and
discuss their phenomenological implications, in particular in view of the
determination of the polarized gluon distribution


title: Top quark production near threshold: NNLO QCD correction

abstract:
  We calculate the cross section of the process e^+e^- \to t\bar t near
threshold by resumming Coulomb-like terms with next-to-next-to-leading (NNLO)
accuracy. The nonrelativistic Green function formalism and the method of
``direct matching'' are used. The NNLO correction turns out to be large, of the
same size as the NLO correction. It changes the position and the normalization
of the 1S-peak. The obtained results are compared with results existing in the
literature.


title: Charm Production and Fragmentation in Charged Current DIS

abstract:
  In charged current deep inelastic scattering charm is dominantly produced in
scattering events on strange quarks, thereby allowing for an experimental
determination of the nucleon's strange sea density. A measurement of the energy
spectrum of final state charm fragments (D-mesons) determines the charm
fragmentation function at spacelike scales considerably below typical e^+e^-
c.m.s. energies. NLO corrections to the naive s -> c parton model production
picture are important and well understood.


title: Grand Unification and B & L Conservation

abstract:
  A review of baryon and lepton conservation in supersymmetric grand unified
theories is given. Proton stability is discussed in the minimal SU(5)
supergravity grand unification and in several non-minimal extensions such as
the $SU(3)^3$, SO(10) and some string based models. Effects of dark matter on
proton stability are also discussed and it is shown that the combined
constraints of dark matter and proton stability constrain the sparticle
spectrum. It is also shown that proton lifetime limits put severe constraints
on the event rates in dark matter detectors. Future prospects for the
observation of baryon and lepton number violation are also discussed.


title: Slepton Oscillation at e-gamma Colliders

abstract:
  We study the possible signature for lepton-flavor violation processes in the
scalar-lepton sector of the minimal supersymmetric model at future
electron-photon colliders. We find that an $\egm$ collider can provide a good
opportunity to probe the mass differences and flavor mixing angles between the
sleptons of the first generation and the other two generations for the
right-handed as well as the left-handed sector. The sensitivity reach for
lepton-flavor violation is comparable to that obtained at an $e^+e^-$ and
$e^-e^-$ collider, and is significantly better than the current bound from
low-energy rare processes such as $\mu \to e \gamma$.


title: kt Effects in Direct-Photon Production

abstract:
  We discuss the phenomenology of initial-state parton-kt broadening in
direct-photon production and related processes in hadron collisions. After a
brief summary of the theoretical basis for a Gaussian-smearing approach, we
present a systematic study of recent results on fixed-target and collider
direct-photon production, using complementary data on diphoton and pion
production to provide empirical guidance on the required amount of kt
broadening. This approach provides a consistent description of the observed
pattern of deviation of next-to-leading order QCD calculations relative to the
direct-photon data, and accounts for the shape and normalization difference
between fixed-order perturbative calculations and the data. We also discuss the
uncertainties in this phenomenological approach, the implications of these
results on the extraction of the gluon distribution of the nucleon, and the
comparison of our findings to recent related work.


title: Searching for H --> tau tau in weak boson fusion at the LHC

abstract:
  Weak boson fusion is a copious source of intermediate mass Higgs bosons at
the LHC. The additional very energetic forward jets in these events provide for
powerful background suppression tools. We analyze the $H \to \tau\tau$ decay
mode for the Standard Model Higgs boson. A parton level analysis of the
dominant physics backgrounds (mainly $Z \to \tau\tau$ and Drell-Yan production
of $\tau$'s) and of reducible backgrounds (from $W+$ jet and $b\bar{b}$
production in association with two jets and subsequent leptonic decays)
demonstrates that this channel allows the observation of $H \to \tau\tau$ in a
low background environment, yielding a significant Higgs signal with an
integrated luminosity of about 30 fb$^{-1}$. The weak boson fusion process thus
allows direct measurement of the $H\tau\tau$ coupling.


title:
Domain Walls and Theta Dependence in QCD with an Effective Lagrangian
  Approach

abstract:
  We suggest an anomalous effective Lagrangian which reproduces the anomalous
conformal and chiral Ward identities and topological charge quantization in
QCD. It is shown that the large N_c Di Vecchia-Veneziano-Witten effective
chiral Lagrangian is locally recovered from our results, along with 1/N_c
corrections, after integrating out the heavy "glueball" fields. All
dimensionful parameters in our scheme are fixed in terms of the quark and gluon
condensates and quark masses. We argue that for a certain range of parameters,
metastable vacua appear which are separated from the true vacuum of lowest
energy by domain walls. The surface tension of the wall is estimated, and the
dynamics of the wall is discussed. The U(1) problem and the physics of the
pseudo-goldstone bosons at different theta angles are addressed within the
effective Lagrangian approach. Implications for axion physics, heavy ion
collisions and the development of the early Universe during the QCD epoch are
discussed.


title: "Just So" Neutrino Oscillations Are Back

abstract:
  Recent evidence for oscillations of atmospheric neutrinos at Super-Kamiokande
suggest, in the simplest see-saw interpretation, neutrino masses such that
`just so' vacuum oscillations can explain the solar neutrino deficit. Super-K
solar neutrino data provide preliminary support for this interpretation. We
describe how the just-so signal---an energy dependent seasonal variation of the
event rate, might be detected within the coming years and provide general
arguments constraining the sign of the variation. The expected variation at
radiochemical detectors may be below present sensitivity, but a significant
modulation in the $^7$Be signal could shed light on the physics of the solar
core---including a direct measure of the solar core temperature.


title: Baryogenesis with QCD Domain Walls

abstract:
  We propose a new baryosymmetric mechanism for baryogenesis which takes place
at the QCD scale and is based on the existence of domain walls separating the
metastable vacua from the lowest energy vacuum. The walls acquire fractional
negative and positive baryon charges, while the observed baryon asymmetry is
due to a non-zero value of the $ \theta $ angle at the temperatures near the
QCD chiral phase transition. The regions of metastable vacuum bounded by walls
carry a negative baryon charge and may contribute a significant fraction of the
dark matter of the Universe.


title: CP Violation in Hyperon Decays

abstract: The theory and phenomenology of CP violation in hyperon decays is summarized.


title: Fermion mass-function in thermal QED3

abstract:
  The gap equation for fermions in a version of thermal QED in three dimensions
is studied numerically in the Schwinger-Dyson formalism. The interest in this
theory has been recently revived since it has been proposed as a model of
high-temperature superconductors. We include wave-function renormalization in
our equations and use a non-bare vertex. We then have to solve a system of two
integral equations by a relaxation algorithm. Fermion and photon self-energies
varying independently with energy and momentum are used, which should produce
more accurate results than in the previous literature. The behaviour of the
theory with increasing temperature and number of fermion flavours is then
carefully analyzed.


title: Functional statistical inference of parton distributions

abstract:
  Bialek, Callan and Strong have recently given a solution of the problem of
determining a continuous probability distribution from a finite set of
experimental measurements by formulating it as a one-dimensional quantum field
theory. This report applies an extension of their formalism to the inference of
functional parton distributions from scattering data.


title: Description of elastic vectormeson production and F_2 by two pomerons

abstract:
  Using the Model of the Stochastic Vacuum many diffractive processes have been
calculated by investigating the dipole-dipole scattering at a cm-energy of 20
GeV. In this work we extend the calculation to larger energies and small
dipoles. We assume that there are two pomerons, the hard- and the soft-pomeron,
which cause the different energy dependence for processes dominated by small or
large dipoles. The physical processes are obtained by smearing the
dipole-dipole amplitude with wavefunctions. For small dipoles the leading
perturbative contribution is taken into account. By that way we can describe in
addition to the already calculated low energy results (20 GeV) also the HERA
data for the considered processes in nearly the whole energy and Q^2 range.


title:
Numerical Toy-Model Calculation of the Nucleon Spin Autocorrelation
  Function in a Supernova Core

abstract:
  We develop a simple model for the evolution of a nucleon spin in a hot and
dense nuclear medium. A given nucleon is limited to one-dimensional motion in a
distribution of external, spin-dependent scattering potentials. We calculate
the nucleon spin autocorrelation function numerically for a variety of
potential densities and distributions which are meant to bracket realistic
conditions in a supernova core. For all plausible configurations the width of
the spin-density structure function is found to be less than the temperature.
This is in contrast with a naive perturbative calculation based on the one-pion
exchange potential which overestimates the width and thus suggests a large
suppression of the neutrino opacities by nucleon spin fluctuations. Our results
suggest that it may be justified to neglect the collisional broadening of the
spin-density structure function for the purpose of estimating the neutrino
opacities in the deep inner core of a supernova. On the other hand, we find no
indication that processes such as axion or neutrino pair emission, which depend
on nucleon spin fluctuations, are substantially suppressed beyond the
multiple-scattering effect already discussed in the literature. Aside from
these practical conclusions, our model reveals a number of interesting and
unexpected insights. For example, the spin-relaxation rate saturates with
increasing potential strength only if bound states are not allowed to form by
including a repulsive core. There is no saturation with increasing density of
scattering potentials until localized eigenstates of energy begin to form.


title: Sine-Gordon Parametric Resonance

abstract:
  We consider the instability of fluctuations in an oscillating scalar field
which obeys the Sine-Gordon equation. We present simple closed-form analytic
solutions describing the parametric resonance in the Sine-Gordon model. The
structure of the resonance differs from that obtained with the Mathieu equation
which is usually derived with the small angle approximation to the equation for
fluctuations. The results are applied to axion cosmology, where the
oscillations of the classical axion field, with a Sine-Gordon self-interaction
potential, constitute the cold dark matter of the universe. When the axion
misalignment angle at the QCD epoch, $\theta_0$, is small, the parametric
resonance of the axion fluctuations is not significant. However, in regions of
larger $\theta_0$ where axion miniclusters would form, the resonance may be
important. As a result, axion miniclusters may disintegrate into finer, denser
clumps. We also apply the theory of Sine-Gordon parametric resonance to
reheating in the Natural Inflation scenario. The decay of the inflaton field
due to the self-interaction alone is ineffective, but a coupling to other
bosons can lead to preheating in the broad resonance regime. Together with the
preheating of fermions, this can alter the reheating scenario for Natural
Inflation.


title: Extraction method of $\gamma$ from semi-inclusive b ---> D s decays

abstract:
  We propose a new method to extract a CP angle $\gamma$ from semi-inclusive
two-body nonleptonic decays, b ---> D^0(\bar{D}^0) s and b ---> D_{CP} s. This
method is free from the unknown long distance strong interaction effects and
gives theoretically cleaner signal than the similar method using exclusive
nonleptonic decays, B ---> D K. We can determine $\gamma$ with 4-$\sigma$
accuracy for 40^o < \gamma < 160^o.


title:
Exclusive electroproduction of vector mesons and transversity
  distributions

abstract:
  We show that the leading twist contribution to exclusive electroproduction of
transversely polarized vector mesons vanishes at all orders in perturbation
theory. Therefore one cannot extract information on the quark transversity
distribution of the nucleon from this reaction. In turn one has that the
produced vector meson is purely longitudinal in the large-Q^2 limit, which
provides a new test of the dominance of leading twist at finite Q^2.


title: Resumming the pressure

abstract:
  The convergence properties of the resummed thermal perturbation series for
the thermodynamic pressure are investigated by comparison with the exact
results obtained in large-N phi^4 theory and possibilities for improvements are
discussed. By going beyond conventional resummed perturbation theory,
renormalization has to be carried out nonperturbatively yet consistently. This
is exemplified in large-N phi^4_4 and in a special large-N \phi^3_6 model that
mimics QED in the limit of large flavour number.


title:
Energy dependence of ratios of multiplicities and their slopes for gluon
  and quark jets

abstract:
  The difference between the ratio of multiplicities and the ratio of their
derivatives on energy for gluon and quark jets is calculated up to
next-to-next-to leading order of perturbative QCD. Its non-zero value is
uniquely defined by the running property of the QCD coupling constant. It is
shown that this difference is rather small compared to values which can be
obtained from experimental data. This disagreement can be ascribed either to
strong non-perturbative terms or to experimental problems with a scale choice,
jets separation and inadequate assignement of soft particles to jets.


title: Instanton Searches at HERA

abstract:
  The present status of our ongoing systematic study of the discovery potential
of QCD-instanton induced events in deep-inelastic scattering at HERA is briefly
reviewed. We emphasize our recent progress in predicting the cross-sections of
instanton-induced processes. Our finalized predictions include a dramatic
improvement of the residual renormalization-scale dependencies and the
specification of a ``fiducial'' kinematical region in the relevant Bjorken
variables extracted from recent lattice simulations. Published upper limits on
instanton-induced cross-sections based on single observables in the final state
such as the flow of strange particles and the multiplicity distribution of
charged particles are already of the order of our estimate. Thus, a decisive
search for instanton-induced events in deep-inelastic scattering at HERA, based
on a multi-observable analysis, seems feasible.


title: 25 years with the Pomeron

abstract:
  This paper is written for "Gribov Memorial Volume", Heavy Ion Physics, Acta
Physica Hungarica. This is a report on my 25 years activity in understanding of
the Pomeron structure. Since I was involved in the Pomeron business moreless
from the beginning, I hope, that this report shows the development of the main
ideas in their historical perspective from the first enthusiastic attempts to
find a simple solution to understanding of the complexity and difficulty of the
problem. In other words, this is a story about a young guy who wanted to
understand everything in high energy interaction, who did his best but who is
still in the beginning, but who has not lost his temper and considers the
Pomeron structure as the beautiful and difficult problem, which deserves his
time and efforts to be solved.


title: Probing the Exotic Particle Content Beyond the Standard Model

abstract:
  We explore the possible exotic particle content beyond the standard model by
examining all its scalar bilinear combinations. We categorize these exotic
scalar fields and show that without the suppression of (A) their Yukawa
couplings with the known quarks and leptons, and (B) the trilinear couplings
among themselves, most are already constrained to be very heavy from the
nonobservation of proton decay and neutron-antineutron oscillations, the
smallness of $K^0 - \bar {K^0}$, $D^0 - \bar {D^0}$ and $B_d^0 - \bar {B_d^0}$
mixing, as well as the requirement of a nonzero baryon asymmetry of the
universe. On the other hand, assumption (B) may be naturally violated in many
models, especially in supersymmetry, hence certain exotic scalars are allowed
to be below a few TeV in mass and would be easily detectable at planned future
hadron colliders. In particular, large cross sections for the distinctive
processes like $\bar p p \to tt,\bar t c$ and $p p \to t t, b b$ would be
expected at the Fermilab Tevatron and CERN LHC, respectively.


title:
Long baseline neutrino oscillation disappearance search using a $\nu$
  beam from muon decays

abstract:
  We study the feasibility of performing a $\nu_\mu$ disappearance
long-baseline experiment using a neutrino beam coming from muon decays. The
advantage of such a technique with respect to the production of neutrino beams
from pions is that in a muon decay both muon and electron neutrinos are
produced in the same quantity. In case of $\nu_\mu\to\nu_{\tau,s}$
oscillations, the $\nu_e$ charged current (CC) events can be used as a control
sample, to predict in situ the $\nu_\mu$ rates, thus reducing the systematics
due to the knowledge of the neutrino flux, which is the main source of
uncertainties for disappearance experiments. We consider as our neutrino
target, the ICARUS detector in its final mass configuration of 4.8 kton.


title: An introduction to Pomerons

abstract:
  This talk is an attempt to clarify for experimentalists what we (theorists)
mean when we are saying "Pomeron". I hope, that in this talk they will find
answers to such questions as what is Pomeron, what we have learned about
Pomeron, both experimentally and theoretically, what is correct strategy to
study Pomeron experimentally and etc. I also hope that this talk could be used
as a guide in the zoo of Pomerons: "soft" Pomeron, "hard" Pomeron, the BFKL
Pomeron, the Donnachie-Landshoff Pomeron and so on. The large number of
different Pomerons just reflects our poor understanding of high energy
asymptotics in out microscopic theory -QCD. The motto of my talk, which gives
you my opinion on the subject in short is:``Pomeron is still unknown but needed
for 25 year to describe experimental data".


title:
Supersymmetric contributions to rare kaon decays: beyond the single
  mass-insertion approximation

abstract:
  We analyze the contributions to rare kaon decays mediated by flavor-changing
Z-penguin diagrams in a generic low-energy supersymmetric extension of the
Standard Model. In order to perform a model-independent analysis we expand the
squark mass matrices around the diagonal, following the so called
mass-insertion approximation. We argue that in the present case it is necessary
to go up to the second order in this expansion to take into account all
possible large effects. The current bounds on such second-order term, which was
neglected in previous analyses, are discussed in detail and the corresponding
upper bounds for the rare kaon decay rates are derived. As a result, we show
that supersymmetric effects could lead to large enhancements of K -> pi nu{\bar
nu} and K_L -> pi^0 e^+ e^- branching ratios.


title: The Case for a Standard Model with Anomalous U(1)

abstract:
  A gauged phase symmetry with its anomalies cancelled by a Green-Schwarz
mechanism, broken at a large scale by an induced Fayet-Iliopoulos term, is a
generic feature of a large class of superstring theories. It induces many
desirable phenomenological features: Yukawa coupling hierarchy, the emergence
of a small Cabibbo-like expansion parameter, relating the Weinberg angle to
$b-\tau$ unification, and the linking of R-parity conservation to neutrino
masses. Some are discussed in the context of a three-family model which
reproduces all quark and lepton mass hierarchies as well as the solar and
atmospheric neutrino oscillations.


title: A Model for Fermion Mass Hierarchies and Mixings

abstract:
  We present a model which contains three Abelian symmetries beyond the
standard model. One is anomalous {\it \` a la} Green-Schwarz, and
family-independent; the other two are family symmetries. All are broken at a
large scale by stringy effects. The model is predictive in the neutrino sector:
large mixing between $\nu_\mu-\nu_\tau$, and {\cal O}$(\lambda^3)$
$\nu_e-\nu_\mu$ mixings. Its natural cut-off is the gauge unification scale,
orders of magnitude below the perturbative string cut-off.


title: Compatibility of $\alpha_s(M_\tau)$ with $\alpha_s(M_Z)$

abstract:
  The current phenomenological determinations of $\alpha_s(M_\tau)$ and
$\alpha_s(M_Z)$ are shown to be only marginally consistent with the QCD
evolution of the strong coupling constant between $M_Z$ and $M_\tau$. This
motivates a revised estimate of $\alpha_s(M_\tau)$ since the perturbative
series used to extract $\alpha_s(M_\tau)$ from the $\tau$ hadronic width
exhibits slow convergence. Pad\'e summation techniques provide an estimate of
these unknown higher-order effects, leading to the revised determination
$\alpha_s(M_\tau)=0.333\pm 0.030 $. This value is 10% smaller than current
estimates, improving the compatibility of phenomenological estimates for
$\alpha_s(M_\tau)$ and $\alpha_s(M_Z)$ with the QCD evolution of the strong
coupling constant.


title: Multiquark states in a Goldstone boson exchange model

abstract:
  We discuss the stability of multiquark systems containing heavy flavours. We
show that the Goldstone boson exchange (GBE) model gives results at variance
with the one-gluon-exchange (OGE) model, i.e. when the GBE model stabilizes a
system the OGE model destabilizes it and vice-versa.


title:
Higher Order Bose-Einstein Correlations test the Gaussian Density Matrix
  Approach

abstract:
  A multiparticle system produced by a large number of independent sources is
described by a gaussian density matrix W. All theoretical approach to
Bose-Einstein Correlatios Cn in high energy physics use this form for W. One of
the most salient consequences of this form is the fact that all higher order
(n>2) moments of the current distribution can be expressed in terms of the
first two. We test this property by comparing the data on C2(Q^2), C3(Q^2) and
C4(Q^2) from pion-p and K-p reactions at 250 GeV/c with the predictions of a
general quantum statistical space-time approach. Even a simplified version of
such approach can account for the data. Previous attempts along these lines,
which did not use the space-time approach, met with difficulties.


title: New Bound on gamma from B^+- -> pi K Decays

abstract:
  A bound on the angle gamma of the unitarity triangle is derived using
experimental information on the CP-averaged branching ratios for the rare
decays B^+- -> pi^+- K^0 and B^+- -> pi^0 K^+-. The theoretical description is
cleaner than the Fleischer-Mannel analysis of the decays B^+- -> pi^+- K^0 and
B^0 -> pi^-+ K^+- in that the two decay rates differ only in a single isospin
amplitude, which has a simple structure in the SU(3) limit. As a consequence,
electroweak penguin contributions and strong rescattering effects can be taken
into account in a model-independent way. The resulting bound excludes values of
cos(gamma) around 0.6 and is thus largely complementary to indirect constraints
derived from a global analysis of the unitarity triangle.


title: Nucleon structure functions in a constituent quark scenario

abstract:
  Using a simple picture of the constituent quark as a composite system of
point-like partons, we construct the polarized parton distributions by a
convolution between constituent quark momentum distributions and constituent
quark structure functions. We achieve good agreement with experiments in the
unpolarized as well as in the polarized case, though a good description of the
recent polarized neutron data requires the introduction of one more parameter.
When our results are compared with similar calculations using non-composite
constituent quarks, the accord with the experiments of the present scheme is
impressive. We conclude that DIS data are consistent with a low energy scenario
dominated by composite constituents of the nucleon.


title: Could the gluon contribution to the proton spin be probed?

abstract:
  Central pseudoscalar production in $pp$ scattering is suppressed at small
values of $Q_\perp$. Such a behavior is expected if the production occurs
through the fusion of two vectors. We argue that an extension of the experiment
could probe the gluon contribution to the proton spin.


title:
Nonperturbative three-point functions of the O(N) sigma model in the 1/N
  expansion at NLO

abstract:
  We present a calculation of the three-point functions of the O(N)-symmetric
sigma model. The calculation is done nonperturbatively by means of a
higher-order 1/N expansion combined with a tachyonic regularization which we
proposed in previous publications. We use the results for calculating the
standard model process ff -> H -> WW nonperturbatively in the quartic coupling
of the scalar sector.


title:
Testing nonperturbative techniques in the scalar sector of the standard
  model

abstract:
  We discuss the current picture of the standard model's scalar sector at
strong coupling. We compare the pattern observed in the scalar sector in
perturbation theory up to two-loop with the nonperturbative solution obtained
by a next-to-leading order 1/N expansion. In particular, we analyze two
resonant Higgs scattering processes, ff -> H -> f'f' and ff -> H -> ZZ, WW. We
describe the ingredients of the nonperturbative calculation, such as the
tachyonic regularization, the higher order 1/N intermediate renormalization,
and the numerical methods for evaluating the graphs.
  We discuss briefly the perspectives and usefulness of extending these
nonperturbative methods to other theories.


title:
A Supersymmetric Solution to the Solar and Atmospheric Neutrino
  Anomalies

abstract:
  The formalism for neutrino flavor change induced by lepton family number
violating interactions is developed for the three-neutrino case, and used to
derive the corresponding flavor change probabilities in matter. Applied to the
solar and atmospheric neutrino fluxes, it is argued that the observed
anomalies, including the zenith dependence for the atmospheric case, could be
due to such interactions.


title:
Lattice calculation of the gluon propagator and the strangeness magnetic
  moment of the nucleon

abstract:
  This contribution summarizes a presentation combining two topics in lattice
QCD. Firstly, the gluon propagator in Landau gauge is calculated in quenched
QCD on a large (32^3x64) lattice at beta=6.0. New structure seen in the
infrared region survives conservative cuts to the lattice data, and serves to
exclude a number of models that have appeared in the literature. Secondly, I
report on a recent lattice QCD calculation of the strangeness magnetic moment
of the nucleon. The result is G_M^s(0) =-0.36 +/- 0.20 . The strangeness Sachs
electric mean-square radius was also found to be small and negative.


title: Photon versus Hadron Interferometry

abstract:
  Photons and mesons are both bosons and therefore satisfy the same
Bose-Einstein statistics. This leads to certain similarities in the
corresponding Bose-Einstein correlations which underly photon and hadron
intensity interferometry. However there are also important differences between
the two effects and these will be analyzed in the following.


title:
CP-violating Z-gamma-gamma and top-quark electric dipole couplings in
  gamma gamma -> t bar{t}

abstract:
  An effective anomalous CP-violating Z-gamma-gamma coupling can give rise to
observable CP-odd effects in gamma gamma -> t bar{t}. We study certain
asymmetries in the decay lepton distributions in gamma gamma -> t bar{t}
arising from top decay in the presence of a CP-violating Z-gamma-gamma coupling
as well as a top-quark electric dipole coupling. We find that a photon linear
collider with geometric luminosity of 20 fb^{-1} can put limits of the order of
0.1 on the imaginary part of the CP-violating anomalous Z-gamma-gamma coupling
using these asymmetries.


title: B--> eta' X_s in the Standard Model

abstract:
  We study $B \to \eta' X_s$ within the framework of the Standard Model.
Several mechanisms such as $b \to \eta' s g$ through the QCD anomaly, and $b
\to \eta's $ and $B\to \eta' s \bar q$ arising from four-quark operators are
treated simultaneously. Using QCD equations of motion, we relate the effective
Hamiltonian for the first mechanism to that for the latter two. By
incorporating next-to-leading-logarithmic(NLL) contributions, the first
mechanism is shown to give a significant branching ratio for $B\to \eta' X_s$,
while the other two mechanisms account for about 15% of the experimental value.
The Standard Model prediction for $B\to \eta' X_s$ is consistent with the CLEO
data.


title:
Three flavor neutrino oscillation analysis of the Superkamiokande
  atmospheric neutrino data

abstract:
  Superkamiokande atmospheric neutrino data for 414 days are analyzed in the
framework of three flavor oscillations with mass hierarchy. It is shown that
the best fit point is very close to the pure maximal
$\nu_\mu\leftrightarrow\nu_\tau$ case and $\Delta m^2 \simeq 7\times10^{-3}$
eV$^2$. The allowed region at 90 %CL is given and the implications to the long
baseline experiments are briefly discussed. It is also shown that the threefold
maximal mixing model fits to the data of atmospheric neutrinos and the reactor
experiments for $\Delta m^2 \sim 1\times10^{-3}$ eV$^2$.


title:
\nu_\mu<->\nu_\tau vs \nu_\mu<->\nu_s solutions for the atmospheric
  neutrino problem

abstract:
  The $\nu_\mu \leftrightarrow\nu_\tau$ and $\nu_\mu \leftrightarrow\nu_s$
solutions to the atmospheric neutrino problem are compared with Superkamiokande
data. Both the solutions with a large mixing angle seem to be consistent with
the data.


title:
Minimal Ten-parameter Hermitian Texture Zeroes Mass Matrices and the CKM
  Matrix

abstract:
  Hermitian mass matrices for the up and down quarks with texture zeroes but
with the minimum number of parameters, ten, are investigated. We show how these
{\em minimum parameter} forms can be obtained from a general set of hermitian
matrices through weak basis transformations. For the most simple forms we show
that one can derive exact and compact parametrizations of the CKM mixing matrix
in terms of the elements of these mass matrices (and the quark masses).


title: New tests for neutrinos in low-energy solar experiments

abstract:
  We show how future solar neutrino experiments in the low energy region can be
used to test novel neutrino properties. Information on the Majorana nature or
neutrino magnetic moments can be extracted from the observation of electron
anti-neutrinos from the Sun and the measurement of an azimuthal asymmetry in
the total number of events, respectively.


title:
Electroweak Baryon Number Violation and Constraints on Left-handed
  Majorana Neutrino Masses

abstract:
  During a large period of time, the anomalous baryon number violating
interactions are in equilibrium, when the $(B+L)$ asymmetry is washed out. If
there is any lepton number violation during this period, that will also erase
the $(B-L)$ asymmetry. As a result, survival of the baryon asymmetry of the
universe pose strong constraints on lepton number violating interactions. We
review here the constraints on the left-handed Majorana neutrino masses arising
from this survival requirement of the baryon asymmetry of the universe. We then
briefly review models of leptogenesis, where lepton number violation is used to
generate a baryon asymmetry of the universe and hence the constraints on the
Majorana neutrino mass is relaxed.


title: Gauge invariant field strength correlators and Abelian dominance in QCD

abstract:
  We establish a relation between the two-point field strength correlator in
QCD and the dual field propagator of the effective dual Abelian Higgs model
describing the infrared behaviour of QCD.


title: Adiabatic surfaces from the lattice: excited gluonic potentials

abstract:
  I describe the results from lattice studies of probing the vacuum with static
colour sources. Topics include
  (i) Twang the flux tube: string models and hybrid mesons.
  (ii) Charge up the flux tube: adjoint and sextet sources.
  (iii) Several sources: how does the colour flux get arranged?


title: Analytic QCD Flavor Thresholds Through Two Loops

abstract:
  In this talk \footnote{Presented at ICHEP'98, Vancouver, CA, July 1998}, we
present a recently suggested way on how to analytically incorporate massive
threshold effects into observables calculated in massless QCD. No matching is
required since the renormalization scale is in this approach connected to the
physical momentum transfer between static quarks in a color singlet state. We
discuss massive fermionic corrections to the heavy quark potential through two
loops. The calculation uses a mixed approach of analytical, computer-algebraic
and numerical tools including Monte Carlo integration of finite terms. Strong
consistency checks are performed by ensuring the proper cancellation of all
non-local divergences by the appropriate counterterms and by comparing with the
massless limit. The size of the effect for the (gauge invariant) fermionic part
of $\alpha_V ({\bf q^2},m^2) $ relative to the massless case at the charm and
bottom flavor thresholds is found to be of order 33%.


title:
Generalized Hypergeometric Functions and the Evaluation of Scalar
  One-loop Integrals in Feynman Diagrams

abstract:
  Present and future high-precision tests of the Standard Model and beyond for
the fundamental constituents and interactions in Nature are demanding complex
perturbative calculations involving multi-leg and multi-loop Feynman diagrams.
Currently, large effort is devoted to the search for closed expressions of loop
integrals, written whenever possible in terms of known - often
hypergeometric-type - functions. In this work, the scalar three-point function
is re-evaluated by means of generalized hypergeometric functions of two
variables. Finally, use is made of the connection between such Appell functions
and dilogarithms coming from a previous investigation, to recover well-known
results.


title:
Dynamical screening away from equilibrium: hard photon production and
  collisional energy loss

abstract:
  We investigate the production rate for hard real photons and the collisional
energy loss in the quark-gluon plasma away from chemical equilibrium. Applying
the Hard-Thermal-Loop resummation scheme away from equilibrium, we can show
that Landau damping provides dynamical screening for both fermion and boson
exchange present in the two quantities.


title:
Optimized Perturbation Theory at Finite Temperature --- Renormalization
  and Nambu-Goldstone theorem in O(N) phi^4 Theory ---

abstract:
  The optimized perturbation theory (OPT) at finite temperature recently
developed by the present authors is reviewed by using O(N) phi^4 theory with
spontaneous symmetry breaking. The method resums automatically higher loops
(including the hard thermal loops) at high $T$ and simultaneously cures the
problem of tachyonic poles at relatively low $T$. We prove that (i) the
renormalization of the ultra-violet divergences can be carried out
systematically in any given order of OPT, and (ii) the Nambu-Goldstone theorem
is satisfied for arbitrary $N$ and for any given order of OPT.


title: CP Violation in B Decays and Strategies for Extracting CKM Phases

abstract:
  A brief review of CP violation in the $B$-meson system and of strategies to
determine the angles $\alpha$, $\beta$ and $\gamma$ of the unitarity triangle
of the CKM matrix is given. Both general aspects and some recent developments
are discussed, including a critical look at the ``benchmark'' modes, CP
violation in penguin decays, $B_s$ decays in the light of the width difference
$\Delta\Gamma_s$, charged $B$ decays, and strategies to probe the CKM angle
$\gamma$ with $B\to\pi K$ modes.


title: Unification and Extra Space-Time Dimensions

abstract:
  We analyse the phenomenological implications of a particular class of
supersymmetric models with additional space-time dimensions below the
unification scale. Assuming the unification of the gauge couplings and using a
two-loop calculation below the scale of the additional space-time dimensions,
we show that the value of $\alpha_3(M_z)$ is further increased from the
two-loop Minimal Supersymmetric Standard Model prediction. We consider whether
decompactification threshold effects could bring $\alpha_3(M_z)$ into agreement
with experiment and discuss the associated level of fine tuning needed.


title:
Magnetic Catalysis and Oscillating Effects in Nambu -- Jona-Lasinio
  Model at Nonzero Chemical Potential

abstract:
  Phase structure of the four dimensional Nambu -- Jona-Lasinio model has been
investigated in two cases: 1) in nonsimply connected space-time of the form
$R^3\times S^1$ (space coordinate is compactified and the length of the circle
$S^1$ is $L$) with nonzero chemical potential $\mu$ and 2) in Minkowski
space-time at nonzero values of $\mu,H$, where $H$ is the external magnetic
field. In both cases on phase portraits of the model there are infinitly many
massless chirally symmetric phases as well as massive ones with spontaneously
broken chiral invariance. Such phase structure leads unavoidably to
oscillations of some physical parameters at $L\to\infty$ or $H\to 0$, including
magnetization, pressure and particle density of the system as well as quark
condensate and critical curve of chiral phase transitions. Phase transitions of
1st and 2nd orders and several tricritical points have been shown to exist on
phase diagrams of the model.


title: Nuclear Effects in the F_3 Structure Function

abstract:
  We discuss nuclear effects in the structure function F_3 measured in neutrino
deep-inelastic scattering on heavy nuclear targets.


title: Physics at the Linear Collider

abstract:
  The physics at the planned $e^+e^-$ colliders is discussed around three main
topics corresponding to different manifestations of symmetry breaking: $W$
physics in the no Higgs scenario, studies of the properties of the Higgs and
precision tests of SUSY. A comparison with the LHC is made for all these cases.
The $\gamma \gamma$ mode of the linear collider will also be reviewed.


title: The chiral phase transition from the exact RG

abstract:
  A brief introduction is given to the concept of the effective average action.
Its dependence on the averaging or coarse graining scale is governed by an
exact RG equation for which nonperturbative approximation schemes are
described. This formalism is applied to the computation of the equation of
state for two flavor QCD within an effective linear quark meson model. Our
results allow to derive the temperature and quark mass dependence of quantities
like the chiral condensate or the pion mass. A precision estimate of the
universal critical equation of state for the three--dimensional O(4) Heisenberg
model is given. The exact RG formalism applied to the linear quark meson model
is demonstrated to provide an explicit link between the O(4) universal behavior
near the critical temperature and zero quark mass on one hand and the physics
at low temperatures and realistic current quark masses, i.e., the domain of
validity of chiral perturbation theory on the other hand.


title:
Impact Parameter Dependence of $J/\psi$ and Drell-Yan Production in
  Heavy Ion Collisions at $\sqrt{s_{NN}} = 17.3$ GeV

abstract:
  In heavy-ion collisions, $J/\psi$ and Drell-Yan production are expected to be
affected by nuclear modifications to the free nucleon structure functions. If
these modifications, known as shadowing, are proportional to the local nuclear
density, the per nucleon cross sections will depend on centrality. Differences
in quark and gluon shadowing will lead to a new source of impact parameter
dependence of the $J/\psi$ to Drell-Yan production ratio. We calculate this
ratio in the CERN NA50 acceptance with several shadowing parameterizations to
explore its centrality dependence.


title: Probing Minimal Supergravity at the CERN LHC for Large $\tan\beta$

abstract:
  For large values of the minimal supergravity model parameter $\tan\beta$, the
tau lepton and the bottom quark Yukawa couplings become large, leading to
reduced masses of $\tau$-sleptons and $b$-squarks relative to their first and
second generation counterparts, and to enhanced decays of charginos and
neutralinos to $\tau$-leptons and $b$-quarks. We evaluate the reach of the CERN
LHC $pp$ collider for supersymmetry in the mSUGRA model parameter space. We
find that values of $m_{\tg}\sim 1500-2000$ GeV can be probed with just 10
fb$^{-1}$ of integrated luminosity for $\tan\beta$ values as high as 45, so
that mSUGRA cannot escape the scrutiny of LHC experiments by virtue of having a
large value of $\tan\beta$. We also perform a case study of an mSUGRA model at
$\tan\beta =45$ where $\tz_2\to \tau\ttau_1$ and $\tw_1\to \ttau_1\nu_\tau$
with $\sim 100%$ branching fraction. In this case, at least within our
simplistic study, we show that a di-tau mass edge, which determines the value
of $m_{\tz_2}-m_{\tz_1}$, can still be reconstructed. This information can be
used as a starting point for reconstructing SUSY cascade decays on an
event-by-event basis, and can provide a strong constraint in determining the
underlying model parameters. Finally, we show that for large $\tan\beta$ there
can be an observable excess of $\tau$ leptons, and argue that $\tau$ signals
might serve to provide new information about the underlying model framework.


title: Extracting Br(omega->pi^+ pi^-) from the Time-like Pion Form-factor

abstract:
  We extract the G-parity-violating branching ratio Br(omega->pi^+ pi^-) from
the effective rho-omega mixing matrix element Pi_{rho omega}(s), determined
from e^+e^- -> pi^+ pi^- data. The omega->pi^+ pi^- partial width can be
determined either from the time-like pion form factor or through the constraint
that the mixed physical propagator D_{rho omega}^{mu nu}(s) possesses no poles.
The two procedures are inequivalent in practice, and we show why the first is
preferred, to find finally Br(omega->pi^+ pi^-) = 1.9 +/- 0.3%.


title: Phase transition of a scalar field theory at high temperatures

abstract:
  At high temperatures a four dimensional field theory is reduced to a three
dimensional field theory. In this letter we consider the $\phi^4$ theory whose
parameters are chosen so that a thermal phase transition occurs at a high
temperature. Using the known properties of the three dimensional theory, we
derive a non-trivial correction to the critical temperature.


title:
Reparametrization Invariance of Heavy Quark Effective Theory at
  O(1/m_Q^3)

abstract:
  We extend the investigation of the reparametrization invariance of Heavy
Quark Effective Theory to O(1/m_Q^3). We show that to this order
reparametrization invariance can only be maintained if the the
reparametrization transformation is renormalized properly.


title:
A quantum kinetic equation for particle production in the Schwinger
  mechanism

abstract:
  A quantum kinetic equation is derived for the description of pair production
in a time-dependent homogeneous electric field $E(t)$. As a source term, the
Schwinger mechanism for particle creation is incorporated. Possible particle
production due to collisions and collisional damping are neglected. The main
result is a kinetic equation of non-Markovian character. In the low density
approximation, the source term is reduced to the leading part of the well known
Schwinger formula for the probability of pair creation. We discuss the momentum
and time dependence of the derived source term and compare with other
approaches.


title: Weak Nonleptonic Omega Decay in Chiral Perturbation Theory

abstract:
  We calculate the weak nonleptonic decay of the Omega^- baryon to octet final
states in heavy baryon chiral perturbation theory (HBChPT). We include the
one-loop leading logarithmic effects and show that this improves the
universality of the HBChPT constants.


title:
The quark-antiquark Wilson loop formalism in the NRQCD power counting
  scheme

abstract:
  The quark-antiquark interaction from the NRQCD Lagrangian is studied in the
Wilson loop formalism.


title:
Some aspects of the quark-antiquark Wilson loop formalism in the NRQCD
  framework

abstract:
  Starting from the NRQCD Lagrangian the heavy quark-antiquark potential is
written in terms of field strength insertions on a static Wilson loop. The
relevant matching coefficients are given at the present status of knowledge.
The short-range, perturbatively dominated, behaviour of the spin-dependent
terms is discussed.


title: Rho parameters from odd and even chirality, thermal QCD sum rules

abstract:
  Like the even chirality correlation functions of, say, the two vector
currents, one can also consider odd chirality correlation functions to write
thermal QCD sum rules. They contain fewer non-perturbative corrections, at
least to the leading order. Here we write such a sum rule for the correlation
function of vector and tensor 'currents'. The odd and even chirality sum rules
are taken together to evaluate the effective parameters of the $\rho$ meson to
second order in temperature. To within errors, the results are consistent and
reproduce the absence of shift in the $\rho$ meson mass to this order.


title: The Rotation Average in Lightcone Time-Ordered Perturbation Theory

abstract:
  We present a rotation average of the two-body scattering amplitude in the
lightcone time($\tau$)-ordered perturbation theory. Using a rotation average
procedure, we show that the contribution of individual time-ordered diagram can
be quantified in a Lorentz invariant way. The number of time-ordered diagrams
can also be reduced by half if the masses of two bodies are same. In the
numerical example of $\phi^{3}$ theory, we find that the higher Fock-state
contribution is quite small in the lightcone quantization.


title: Creation of boson and fermion pairs in strong fields

abstract:
  We analyze a quantum kinetic equation describing both boson and fermion pair
production. We explore the solution of the kinetic equation in its Markovian
limit. The numerical study shows an enhancement (bosons) or a suppression
(fermions) of the pair creation rate according to their quantum statistics. The
modification of the time evolution of the distribution function is small but
for strong fields more pronounced than for weak fields.


title: Neutrino Masses, where do we stand?

abstract:
  I review the status of neutrino physics post-Neutrino~98, including the
implications of solar and atmospheric neutrino data, which strongly indicate
nonzero neutrino masses. LSND and the possible role of neutrinos as hot dark
matter (HDM) are also mentioned. The simplest schemes proposed to reconcile
these requirements invoke a light sterile neutrino in addition to the three
active ones, two of them at the MSW scale and the other two maximally-mixed
neutrinos at the HDM/LSND scale. In the simplest theory the latter scale arises
at one-loop, while the solar and atmospheric parameters $\Delta {m^2}_\odot$ &
$\Delta {m^2}_{atm}$ appear at the two-loop level. The lightness of the sterile
neutrino, the nearly maximal atmospheric neutrino mixing, and the generation of
$\Delta {m^2}_\odot$ & $\Delta {m^2}_{atm}$ follow naturally from the assumed
lepton-number symmetry and its breaking. These two basic schemes can be
distinguished at future solar & atmospheric neutrino experiments and have
different cosmological implications.


title:
Determine the parameter Bk of the K0-K0bar system by means of the
  precise Cabibbo-Kobayashi-Maskawa matrix elements

abstract:
  Taking use of the relation between weak CP phase and the other three mixing
angles in Cabibbo-Kobayashi-Maskawa matrix postulated by us before, the
uncertainty coming from the weak interaction can be reduced, furthermore, by
means of the relation between the calculation result about mixing parameter
epsilon from the box diagrams and the related experimental data in K0-K0bar
system, the parameter Bk can be extracted. We take Vud, Vub and Vtb as inputs,
when we let them vary in the ranges 0.9745<=Vud<=0.9760, 0.0018<=Vub<=0.0045
and 0.9991<=Vtb<=0.9993, we find the permitted window for Bk is
0.444<=Bk<=1.242. With the more precise measurment on the CKM matrix elements
in the future, we can determine Bk more precisely.


title:
Estimate the Ranges of rho and eta only from the Kobayashi-Maskawa
  Matrix Elements of the First Two Generations

abstract:
  Based on the relation between weak CP phase and the other three mixing angles
in Cabibbo-Kobayashi-Maskawa matrix postulated by us before, the ranges of rho
and eta have been estimated by using the best known two KM matrix elements Vud
and Vcd (or Vus). It is found that, the upper limit on eta is about 0.008 which
is consistent with that estimated by Wolfenstein more than ten years ago but
far small than the present popular estimation.


title: The Effective Electroweak Chiral Lagrangian: The Matter Sector

abstract:
  We parametrize in a model-independent way possible departures from the
minimal Standard Model predictions in the matter sector. We only assume the
symmetry breaking pattern of the Standard Model and that new particles are
sufficiently heavy so that the symmetry is non-linearly realized. Models with
dynamical symmetry breaking are generically of this type. We review in the
effective theory language to what extent the simplest models of dynamical
breaking are actually constrained and the assumptions going into the comparison
with experiment. Dynamical symmetry breaking models can be approximated at
intermediate energies by four-fermion operators. We present a complete
classification of the latter when new particles appear in the usual
representations of the $SU(2)_L\times SU(3)_c$ group as well as a partial
classification in the general case. We discuss the accuracy of the four-fermion
description by matching to a simple `fundamental' theory. The coefficients of
the effective lagrangian in the matter sector for dynamical symmetry breaking
models (expressed in terms of the coefficients of the four-quark operators) are
then compared to those of models with elementary scalars (such as the minimal
Standard Model). Contrary to a somewhat widespread belief, we see that the sign
of the vertex corrections is not fixed in dynamical symmetry breaking models.
This work provides the theoretical tools required to analyze, in a rather
general setting, constraints on the matter sector of the Standard Model.


title: The Two Faces of the Axial Anomaly and Proton Spin

abstract: This paper has been withdrawn by authors for significant modification.


title:
Combining the data of annual modulation effect in WIMP direct detection
  with measurements of WIMP indirect searches

abstract:
  In previous papers we showed that the data of the DAMA/NaI experiment for
WIMP direct detection, which indicate a possible annual modulation effect, are
widely compatible with an interpretation in terms of a relic neutralino as the
major component of dark matter in the Universe. In the present note we discuss
the detectability of the relevant supersymmetric neutralino configurations by
two of the most promising methods of indirect search for relic particles:
measurement of cosmic-ray antiprotons and measurement of neutrino fluxes from
Earth and Sun.


title:
Production of Z Boson Pairs via Gluon Fusion in the Minimal
  Supersymmetric Model

abstract:
  We present the full one-loop calculation for $gg \to ZZ$ in the Minimal
Supersymmetric Model (MSSM) including nonresonant contributions from the squark
loop diagrams and provide analytical expressions for the helicity amplitudes.
The one-loop process $gg \to ZZ$ via quark loops has been calculated in the
Standard Model. In supersymmetric models, additional contributions arise from
squark loops. In some regions of the MSSM parameter space, the top and bottom
squark loops can make important contributions to the diagrams involving Higgs
bosons. The heavy Higgs scalar (H) might be detected at the Large Hadron
Collider via $gg \to H \to ZZ$ for $\tan\beta \alt 5$.


title:
A Color Mutation Hadronic Soft Interaction Model -- Eikonal Formalism
  and Branching Evolution

abstract:
  ECOMB is established as a hadronic multiparticle production generator by soft
interaction. It incorporates the eikonal formalism, parton model, color
mutation, branching, resonance production and decay. A partonic cluster, being
color-neutral initially, splits into smaller color-neutral clusters
successively due to the color mutation of the quarks. The process stops at
hadronic resonance, $q\bar q$ pair, formation. The model contains self-similar
dynamics and exhibits scaling behavior in the factorial moments, e.g. the
intermittency.


title:
Probing Grand Unified Theories with Cosmic Ray, Gamma-Ray and Neutrino
  Astrophysics

abstract:
  We explore scenarios where the highest energy cosmic rays are produced by new
particle physics near the grand unification scale. Using detailed numerical
simulations of extragalactic nucleon, gamma-ray, and neutrino propagation, we
show the existence of an interesting parameter range for which such scenarios
may explain part of the data and are consistent with all observational
constraints. A combination of proposed observatories for ultra-high energy
cosmic rays, neutrino telescopes of a few kilometer scale, and gamma-ray
astrophysics instruments should be able to test these scenarios. In particular,
for neutrino masses in the eV range, exclusive neutrino decay modes of
superheavy particles can give rise to neutrino fluxes comparable to those
predicted in models of active galactic nuclei.


title: The Quark Distributions in the \Sigma^+ Hyperon

abstract:
  We use the meson cloud model and the Sullivan mechanism to estimate the sea
flavor asymmetry in the \Sigma^+ baryon and calculate the distribution
functions of both sea and valence quarks. We find large deviations from SU(3).


title:
The phenomenology of $W^\pm H^\mp$ production at the Large Hadron
  Collider

abstract:
  Barrientos Bendezu' and Kniehl [hep-ph/9807480] recently suggested that
$W^\pm H^\mp$ associated production may be a useful channel in the search for
the elusive heavy charged Higgs bosons of the 2 Higgs Doublet Model at the
Large Hadron Collider. We investigate the phenomenology of this mechanism in
the Minimal Supersymmetric Standard Model, with special attention paid to the
most likely heavy Higgs decay, $H^\mp\to tb\to b\bar b W^\mp$, and to the
irreducible background from top pair production. We find that the semi-leptonic
signature `$b\bar b W^+W^-\to b\bar b jj \ell$ + missing momentum' is dominated
by top-antitop events, which overwhelm the charged Higgs signal over the heavy
mass range that can be probed at the CERN collider


title:
Application of Jain and Munczek's bound-state approach to gamma
  gamma-processes of pi0, eta_c and eta_b

abstract:
  We point out the problems affecting most quark--antiquark bound state
approaches when they are faced with the electromagnetic processes dominated by
Abelian axial anomaly. However, these problems are resolved in the consistently
coupled Schwinger-Dyson and Bethe-Salpeter approach. Using one of the most
successful variants of this approach, we find the dynamically dressed
propagators of the light u and d quarks, as well as the heavy c and b quarks,
and find the Bethe-Salpeter amplitudes for their bound states pi0, eta_c and
\eta_b. Thanks to incorporating the dynamical chiral symmetry breaking, the
pion simultaneously appears as the (pseudo)Goldstone boson. We give the
theoretical predictions for the gamma-gamma decay widths of pi0, eta_c and
eta_b, and for the pi0 gamma* -> gamma transition form factor, and compare them
with experiment. In the chiral limit, the axial-anomaly result for
pi0->gamma-gamma is reproduced analytically in the consistently coupled
Schwinger-Dyson and Bethe-Salpeter approach, provided that the quark-photon
vertex is dressed consistently with the quark propagator, so that the vector
Ward-Takahashi identity of QED is obeyed. On the other hand, the present
approach is also capable of quantitatively describing systems of heavy quarks,
concretely eta_c and possibly eta_b, and their gamma-gamma decays. We discuss
the reasons for the broad phenomenological success of the bound-state approach
of Jain and Munczek.


title:
Anomalous Hypercharge Axial Current And The Couplings Of The eta And f_1
  (1420) Mesons To The Nucleon

abstract:
  It is argued that the precise three flavor symmetry of hadrons is not SU(3)_F
but rather U(4)_F restricted to SU(2)_{ud}*SU(2)_{cs}*U(1) and considered in
the limit of frozen charm degree of freedom. Within this scheme the only
hypercharge generator which is consistent with the Gell-Mann--Nishijima
relation appears to be an element of the su(2)_{cs}*u(1) subalgebra as it
contains the unit matrix generating the baryon number current. In considering
now hypercharge axial transformations, the u(1) generator will give rise to the
anomalous U(1)_A axial current and the resulting hypercharge axial current will
be anomalous, too. The only anomaly free neutral strong axial current having a
well defined chiral limit turns out to be identical (up to a constant factor)
with the weak axial current, and the eta meson acquires features of a `masked'
strange Goldstone boson. The eta N and f_1(1420)N couplings will now proceed
via a purely strange isosinglet axial current and appear strongly suppressed
relative to the predictions of the octet quark model. For this reason, loop
corrections like the a_0\pi N and KK^*Y triangles to the respective eta NN and
f_1(1420)NN vertices acquire importance. Here we calculate them in using
effective lagrangians and show that the model developed is convenient for data
description beyond the limits of applicability of chiral perturbation theory.


title:
Two-loop enhancement factor for 1/Q corrections to event shapes in deep
  inelastic scattering

abstract:
  We compute the two-loop enhancement factors for our earlier one-loop
calculations of leading (1/Q) power corrections to the mean values of some
event shape variables in deep inelastic lepton scattering. The enhancement is
found to be equal to the universal ``Milan factor'' for those shape variables
considered, provided the one-loop calculation is performed in a particular way.
As a result, the phenomenology of power corrections to DIS event shapes remains
largely unaffected.


title:
A Systematic Study of Power Corrections from World Deep Inelastic
  Scattering Measurements

abstract:
  By performing an analysis in moment space using high statistics DIS world
data, we extract the values of both the QCD parameter
$\Lambda^{(4)}_{\bar{MS}}$ up to NLO and of the power corrections to the proton
structure function, $F_2$. At variance with previous analyses, the use of
moments allows us to extend the kinematical range to larger values of $x$,
where we find that power corrections are quantitatively more important. Our
results are consistent with the $n$ dependence predicted by IR renormalon
calculations. We discuss preliminary results on nuclear targets with the intent
of illustrating a possible strategy to disentangle power corrections ascribed
to IR renormalons from the ones generated dynamically e.g. from rescattering in
the final state. The latter appear to be modified in nuclear targets.


title:
Exclusive and Inclusive Decays of the B_c Meson in the Light-Front ISGW
  Model

abstract:
  We investigate the total decay rate of the (ground state) $B_c$ meson within
the framework of the relativistic constituent quark model formulated on the
light-front (LF). The exclusive semileptonic (SL) and nonleptonic (NL) beauty
and charm decays of the $B_c$ meson are described through vector and axial
hadronic form factors, which are calculated in terms of the overlap of the
parent and daughter LF wave functions. The latters are derived via the
Hamiltonian LF formalism using as input the update version of the ISGW model.
The inclusive SL and NL partial rates are calculated within a convolution
approach inspired by the partonic model and involving the same $B_c$ wave
function which is used for evaluation of the exclusive modes. We predict the
partial rates for 74 exclusive SL and NL channels and 43 inclusive partial
rates corresponding to the underlying $\bar{b}\to \bar{c}$ and $c\to s$ quark
decays. Based on our approach we find $\Gamma^{\bar{b}}(B_c)= 0.52 \pm 0.02
ps^{-1}$, $\Gamma^{c}(B_c)= 0.98 \pm 0.07 ps^{-1}$, where the theoretical
uncertainty is dominated by the uncertainty in the choice of the threshold
values at which the hadron continuum starts. For the $B_c$ lifetime we obtain
$\tau_{B_c}= 0.63 \pm 0.02 ps$ in a good agreement with the prediction obtained
using the nonrelativistic operator product expansion. We also predict decay
rates for many specific weak transitions of $B_c$. In particular, for the
branching fractions of the $B^+_c \to J/\psi\mu^+\nu_{\mu}$, $B_c^+\to
J/\psi\pi^+$ and $B_c^+ \to J/\psi+X $ decays we obtain 1.7%, 0.1 % and 13.2%,
respectively.


title: Infra-red stability of Yukawa and soft-breaking fixed points

abstract:
  We investigate the infra-red stability of the fixed points in the evolution
of the Yukawa couplings, $A$-parameters and soft scalar masses in a broad class
of supersymmetric theories. We show that the issue of stability is essentially
determined in all three cases by the eigenvalues of the same matrix. In a very
wide range of physically interesting theories it follows that, in the
asymptotically free case, the existence of stable infra-red fixed points for
the Yukawa couplings implies stable infra-red fixed points for the
$A$-parameters and soft scalar masses.


title:
Thermal Renormalization Group-Equations and the Phase-Transition of
  Scalar O(N)-Theories

abstract:
  We discuss the formulation of "thermal renormalization group-equations" and
their application to the finite temperature phase-transition of scalar
O(N)-theories. Thermal renormalization group-equations allow for a computation
of both the universal and the non-universal aspects of the critical behavior
directly in terms of the zero-temperature physical couplings. They provide a
nonperturbative method for a computation of quantities like real-time
correlation functions in a thermal environment, where in many situations
straightforward perturbation theory fails due to the bad infrared-behavior of
the thermal fluctuations. We present results for the critical temperature,
critical exponents and amplitudes as well as the scaling equation of state for
self-interacting scalar theories.


title:
A medium baseline search for $\nu_\mu\to\nu_e$ oscillations at a $\nu$
  beam from muon decays

abstract:
  The accurate knowledge of the $\bar\nu_e (\nu_\mu)$ beam produced in $\mu^-$
decays and the absence of $\nu_e (\bar\nu_\mu)$ contamination, make a future
muon storage ring the ideal place to look for $\numunue$ ($\numubarnuebar$)
oscillations. Using a detector capable of electron and muon identification with
charge discrimination (e.g., the presently running NOMAD experiment), good
sensitivities to $\numunue (\numubarnuebar)$ oscillations could be achieved.
With the CERN-PS as a proton driver for a muon storage ring of the kind
envisaged for a $\mu$-collider, the LSND claim would be confirmed or disproved
in a few years of running.


title:
R-parity violation and uses of the rare decay sneutrino-->gamma+gamma in
  hadron and photon colliders

abstract:
  We consider implications of the loop process sneutrino -> gamma gamma in the
MSSM with R-parity violation for future experiments, where the sneutrino is
produced as the only supersymmetric particle. We present a scenario for the
R-parity violating couplings, where this clean decay, although rare with
Br(sneutrino -> gamma gamma) ~ 10^{-6}, may be useful for sneutrino detection
over a range of sneutrino masses at the LHC. Furthermore, the new
sneutrino-gamma-gamma effective coupling may induce detectable sneutrino
resonant production in gamma gamma collisions, over a considerably wide mass
range. We compare sneutrino -> gamma gamma, gg throughout the paper with the
analogous yet quantitatively very different, Higgs -> gamma gamma, gg decays
and comment on the loop processes sneutrino -> WW, ZZ.


title:
Charm and Bottom Baryon Decays in the Bethe-Salpeter Approach: Heavy to
  Heavy Semileptonic Transitions

abstract:
  Charm and bottom baryons and mesons are studied within the framework of a
relativistically covariant 3D reduction of the Bethe-Salpeter equation. We
carry out an analysis of semileptonic decays of heavy hadrons within this
framework using explicit oscillator-type wave functions where we calculate
Isgur-Wise functions, decay rates and asymmetry parameters. Within this model
we also study the effect of interactions between the light quarks inside the
heavy baryon and how they affect the values of the computed heavy baryon
observables. We also elaborate on the role of relativistic effects in the
calculation of the heavy baryon Isgur-Wise function.


title: Valence Quark Spin Distribution Functions

abstract:
  The hyperfine interactions of the constituent quark model provide a natural
explanation for many nucleon properties, including the Delta-N splitting, the
charge radius of the neutron, and the observation that the proton's quark
distribution function ratio d(x)/u(x)->0 as x->1. The hyperfine-perturbed quark
model also makes predictions for the nucleon spin-dependent distribution
functions. Precision measurements of the resulting asymmetries A_1^p(x) and
A_1^n(x) in the valence region can test this model and thereby the hypothesis
that the valence quark spin distributions are "normal".


title:
Sum rules for $e^+e^- \to W^+W^-$ helicity amplitudes from BRS
  invariance

abstract:
  The BRS invariance of the electroweak gauge theory leads to relationships
between amplitudes with external massive gauge bosons and amplitudes where some
of these gauge bosons are replaced with their corresponding Nambu-Goldstone
bosons. Unlike the equivalence theorem, these identities are exact at all
energies. In this paper we discuss such identities which relate the process
$e^+e^- \to W^+W^-$ to $W^\pm\chi^\mp$ and $\chi^+\chi^-$ production. By using
a general form-factor decomposition for $e^+e^- \to W^+W^-$, $e^+e^- \to W^\pm
\chi^\mp$ and $e^+e^- \to \chi^+\chi^-$ amplitudes, these identities are
expressed as sum rules among scalar form factors. Because these sum rules may
be applied order by order in perturbation theory, they provide a powerful test
of higher order calculations. By using additional Ward-Takahashi identities we
find that the various contributions are divided into separately gauge-invariant
subsets, the sum rules applying independently to each subset. After a general
discussion of the application of the sum rules we consider the one-loop
contributions of scalar-fermions in the Minimal Supersymmetric Standard Model
as an illustration.


title:
On the exact conservation laws in thermal models and the analysis of AGS
  and SIS experimental results

abstract:
  The production of hadrons in relativistic heavy ion collisions is studied
using a statistical ensemble with thermal and chemical equilibrium. Special
attention is given to exact conservation laws, i.e. certain charges are treated
canonically instead of using the usual grand canonical approach. For small
systems, the exact conservation of baryon number, strangeness and electric
charge is to be taken into account. We have derived compact, analytical
expressions for particle abundances in such ensemble. As an application, the
change in $K/\pi$ ratios in AGS experiments with different interaction system
sizes is well reproduced. The canonical treatment of three charges becomes
impractical very quickly with increasing system size. Thus, we draw our
attention to exact conservation of strangeness, and treat baryon number and
electric charge grand canonically. We present expressions for particle
abundances in such ensemble as well, and apply them to reproduce the large
variety of particle ratios in GSI SIS 2 A GeV Ni-Ni experiments. At the
energies considered here, the exact strangeness conservation fully accounts for
strange particle suppression, and no extra chemical factor is needed.


title:
The light baryon spectrum and the exchange of pseudoscalar and vector
  mesons among constituent quarks

abstract:
  The effects of the exchanges of both pseudoscalar and vector mesons among
constituent quarks on the mass spectra of light baryons are investigated,
paying particular attention to the contribution of tensor and spin-orbit terms.
It is shown that the latter ones heavily affect the calculated spectra at
variance with the empirical observation of the weakness of the baryon
spin-orbit splittings. The relativistic suppression of the strength of the
interaction among light quarks is argued to be a possible way to reproduce the
light-baryon mass spectra.


title: Supersymmetric particle production at hadron colliders

abstract:
  The theoretical status of MSSM particle production at the hadron colliders
Tevatron and LHC is reviewed, including next-to-leading order supersymmetric
QCD corrections. The higher-order corrections significantly reduce the
theoretical uncertainty and lead to a rise of the lower bounds on
supersymmetric particle masses, as demonstrated for the case of top-squark and
gaugino pair production at the Tevatron.


title: Colour Octet effects in Quarkonium Physics

abstract:
  The importance of including colour octet contributions in describing decay
and production of quarkonium states is briefly discussed for two cases : the
radiative decays of the $\Upsilon$ and the production of $J/\psi$ in the
inclusive $B$ decays. It is shown how information on the non-perturbative
matrix elements can be obtained by comparing the theoretical expressions
computed at next-to-leading order in $\alpha_s$ with the experimental data.


title:
Exact Conservation of Quantum Numbers in the Statistical Description of
  High Energy Particle Reactions

abstract:
  Relativistic heavy ion collisions are studied taking the exact conservation
of baryon number, strangeness and charge explicitly into account.


title: The CP violating asymmetry in $B^{\pm} \to M {\bar M} \pi^{\pm}$ decays

abstract:
  We analyze the asymmetry in the partial widths for the decays $B^{\pm} \to M
{\bar M} \pi^{\pm}$ ($ M = \pi^+, K ^+, \pi^0, \eta$), which results from the
interference of the nonresonant decay amplitude with the resonant amplitude for
$B^{\pm} \to \chi_{c0} \pi^{\pm} $ followed by the decay $\chi_{c0} \to M {\bar
M} $. The CP violating phase $\gamma$ can be extracted from the measured
asymmetry. We find that the partial width asymmetry for $B^\pm \to \pi^+ \pi^-
\pi^\pm$ is about $0.33~sin \gamma$, and about $0.45~ sin \gamma$ for $B^\pm
\to K^+ K^-\pi^\pm$, while it is somewhat smaller for $B^\pm \to \pi^0 \pi^0
\pi^\pm$ and $B^\pm \to \eta \eta \pi^\pm$. Potential sources of uncertainties
in these results, primarily coming from poorly known input parameters, are
discussed.


title: Quark dynamics and flux tube structure in qqbar bound states

abstract:
  I discuss the bound state quark dynamics focusing on the nonperturbative
interaction and the flux tube structure.


title:
Longitudinal and transverse structure functions of proton and deuteron
  at large x

abstract:
  Higher-twist effects in the low-order moments of the longitudinal and
transverse structure functions of proton and deuteron have been analyzed using
available phenomenological fits of existing data in the Q**2 range between 1
and 20 (GeV/c)**2. Both twist-4 and twist-6 contributions have been determined
adopting the Natchmann definition of moments, which allows to disentangle
properly target-mass effects. The extraction of the matrix elements of the
relevant twist-4 operators, describing quark-quark and quark-gluon
correlations, is carried out in case of the second moment. The need of
transverse data with better quality for x > 0.5 and Q**2 < 10 (GeV/c)**2 as
well as more precise and systematic determinations of the L/T separation make
JLab @ 12 GeV a good place to improve our understanding of the non-perturbative
structure of hadrons.


title: Baryon Asymmetry, Lepton Mixing and SO(10) Unification

abstract:
  Baryogenesis appears to require lepton number violation. This is naturally
realized in extensions of the standard model containing right-handed neutrinos.
We discuss the generation of a baryon asymmetry by the out-of-equilibrium decay
of heavy Majorana neutrinos in these models, without and with supersymmetry.
All relevant lepton number violating scattering processes which can inhibit the
generation of an asymmetry are taken into account. We assume a similar pattern
of mixings and masses for neutrinos and up-type quarks, as suggested by SO(10)
unification. This implies that B-L is broken at the unification scale
\Lambda_{GUT}\sim 10^{16} GeV, if m_{\nu_\mu} \sim 3\cdot10^{-3} eV, as
preferred by the MSW solution to the solar neutrino deficit. The observed
baryon asymmetry is then obtained without any fine tuning of parameters.


title: Production mechanisms of charm hadrons in the string model

abstract:
  In the hadroproduction of charm in the context of string fragmentation, the
pull of a beam remnant at the other end of a string may give a charm hadron
more energy than the perturbatively produced charm quark. The collapse of a
low-mass string to a single hadron is the extreme case in this direction, and
gives rise to asymmetries between charm and anticharm hadron spectra. We study
these phenomena, and develop models that describe the characteristics not only
of the charm hadrons but also of the associated event.


title: Time evolution of observables out of thermal equilibrium

abstract:
  We propose a new approximation-technique to deal with the exact macroscopic
integro-differential evolution equations of statistical systems which
self-consistently accounts for dissipative effects. Concentrating on one and
two point equal-time correlators, we develop the self-consistent method and
apply it to a scalar field theory with quartic self-interaction. We derive the
effective equations of motion and the corresponding macroscopic effective
Hamiltonian. Non-locality in time appears in a natural way necessary to account
for entropy generating processes.


title: Physics of Strange Matter

abstract:
  Relativistic heavy ion collisions offer the possibility to produce exotic
metastable states of nuclear matter containing (roughly) equal number of
strangeness compared to the content in baryon number. The reasoning of both
their stability and existence, the possible distillation of strangeness
necessary for their formation and the chances for their detection are reviewed.
In the later respect emphasize is put on the properties of small lumps of
strange quark matter with respect to their stability against strong or weak
hadronic decays. In addition, implications in astrophysics like the properties
of neutron stars and the issue of baryonic dark matter will be discussed.


title: What is the upper limit on the lightest supersymmetric Higgs mass?

abstract:
  In this talk the question of what is the upper bound on the lightest
supersymmetric Higgs mass, m_h is addressed. This question is relevant since
experimental lower bounds on m_h might implement, in the near future, exclusion
of supersymmetry. By imposing (perturbative) unification of the gauge couplings
at some high scale \simgt 10^{17} GeV, we have found that for a top-quark mass
M_t=175 GeV, and depending on the supersymmetric parameters, this bound can be
as high as 205 GeV.


title: Complete renormalization group improvement of QCD perturbation theory

abstract:
  We suggest that at any given order of Feynman diagram calculation all
renormalization group (RG)-predictable terms should be resummed to all-orders.
This ``complete'' RG-improvement (CORGI) serves to separate the perturbation
series into infinite subsets of terms which when summed are renormalization
scheme (RS)-invariant. Crucially all ultraviolet logarithms involving the
dimensionful parameter, Q, on which the observable depends are resummed,
thereby building the correct Q-dependence. There are close connections with the
effective charge approach of Grunberg.


title:
Next-to-Minimal Supersymmetric Standard Model and direct Dark Matter
  detection

abstract:
  Prospects for direct dark matter detection are considered in the
Next-to-Minimal Supersymmetric Standard Model (NMSSM). The effective
neutralino-quark Lagrangian is obtained and event rates are calculated for
Ge-73. Accelerator and cosmological constraints on the NMSSM are included in
our numerical analysis, which allows us to conclude that the lightest
neutralino from NMSSM could be detected in future dark matter experiments.


title: The Dualized Standard Model and its Applications

abstract:
  The Dualized Standard Model offers a natural explanation for Higgs fields and
3 generations of fermions plus a perturbative method for calculating SM
parameters. By adjusting only 3 parameters, 14 quark and lepton masses and
mixing parameters (including $\nu$ oscillations) are calculated with general
good success. Further predictions are obtained in post-GZK air showers and FCNC
decays.


title: Hard Thermal Loops in Chiral Perturbation Theory

abstract:
  It is shown how the hard thermal loop approximation can be used in chiral
perturbation theory to study some thermal properties of Goldstone bosons. Hard
thermal effects are first studied in the non-linear sigma model. Then those
results are used to obtain the thermal corrections to the transverse and
longitudinal gauge field masses in the electroweak theory in the limit of a
strongly interacting Higgs boson.


title:
Analysis of Bose-Einstein correlations in e+e- -> W+W- events including
  final state interactions

abstract:
  Recently DELPHI Collaboration reported new data on Bose-Einstein correlations
(BEC) measured in e+e- -> W^+W^- events. Apparently no enhancement has been
observed. We have analyzed these data including final state interactions (FSI)
of both Coulomb and strong (s-wave) origin and found that there is enhancement
in BEC but it is overshadowed by the FSI which are extremely important for
those events. We have found the following values for the size of the
interaction range beta and the degree of coherence lambda: beta=0.87 +/- 0.31fm
and lambda=1.19 +/- 0.48, respectively.


title: The effective potential in the presence of several mass scales

abstract:
  We consider the problem of improving the effective potential in mass
independent schemes, as e.g. the $\MSbar$ or $\DRbar$ renormalization scheme,
in the presence of an arbitrary number of fields with $\phi$-dependent masses
$M_i(\phi_c)$. We use the decoupling theorem at the scales $\mu_i=M_i(\phi_c)$
such that the matching between the effective (low energy) and complete (high
energy) one-loop theories contains no thresholds. We find that for any value of
$\phi_c$, there is a convenient scale $\mu^*\equiv\min_i\{M_i(\phi_c)\}$, at
which the loop expansion has the best behaviour and the effective potential has
the least $\mu$-dependence. Furthermore, at this scale the effective potential
coincides with the (improved) tree-level one in the effective field theory. The
decoupling method is explicitly illustrated with a simple Higgs-Yukawa model,
along with its relationship with other decoupling prescriptions and with
proposed multi-scale renormalization approaches. The procedure leads to a nice
suppression of potentially large logarithms and can be easily adapted to
include higher-loop effects, which is explicitly shown at the two-loop level.


title: The Spectrum and Effective Action of SUSY Gluodynamics

abstract:
  We study the low-energy spectrum of SUSY gluodynamics using the generating
functional for Green's functions of composite fields. Two dual formulations of
the generating functional approach are given. Masses of the bound states are
calculated and mixing patterns are discussed. Mass splittings of pure gluonic
states, in the case when supersymmetry is softly broken, are consistent with
predictions of conventional Yang-Mills theory. The results can be tested in
lattice simulations of the SUSY Yang-Mills model.


title:
Hard Exclusive Electroproduction of Pseudoscalar Mesons and QCD axial
  anomaly

abstract:
  The hard exclusive electroproduction of $\pi^0,\eta,\eta'$ mesons by the
longitudinal photons is considered. We calculate the ratios of the $\pi^0 :
\eta : \eta'$ yields for the electroproduction processes off nucleons and
deuterons based on the QCD factorization theorem, the low energy QCD chiral
dynamics, and the QCD anomaly. Thus investigation of these ratios gives a new
way to probe the physics of the spontaneous chiral symmetry breaking.


title:
Sensitivity of HBT interferometry to the microscopic dynamics of
  freeze-out

abstract:
  We study the HBT interferometry of ultra-relativistic nuclear collisions
using a freezeout model in which free pions emerge in the course of the last
binary collisions in the hadron gas. We show that the HBT correlators of both
identical and non-identical pions change with respect to the case of
independent pion production. Practical consequences for the design of the event
generator with the built in Bose-Einstein correlations are discussed. We argue
that the scheme of inclusive measurement of the HBT correlation function does
not require the symmetrization of the multi-pion transition amplitudes
(wave-functions).


title: Duality in Inclusive Semileptonic Heavy Quark Decay

abstract:
  I identify a source of Lambda_{QCD}/m_Q corrections to the assumption of
quark-hadron duality in the application of heavy quark methods to inclusive
heavy quark semileptonic decays Q->q l nu_l. These corrections could
substantially affect the accuracy of such methods in practical applications and
in particular compromise their utility for the extraction of the
Cabibbo-Kobayashi-Maskawa matrix element V_{cb}.


title: \pi\pi scattering at low energy: status report

abstract:
  I discuss the status of ongoing work to determine numerically the elastic
$\pi\pi$ scattering amplitude at order $p^6$ in the framework of chiral
perturbation theory.


title:
Comment on the absence of Coulomb effects on $e^+e^-$ pair production in
  ultrarelativistic heavy-ion collisions

abstract:
  In recent works [Segev,Wells; Baltz, McLerran; Eichmann, Reinhardt, Schramm,
Greiner] it was claimed that the Coulomb correction to the $e^+e^-$ production
cross section in relativistic heavy-ion collisions is absent. We point out that
this statement is in obvious contradiction to some well known results. We
obtain large Coulomb corrections in the pair production cross section for the
RHIC and LHC heavy-ion colliders.


title:
Prospects for Direct CP Violaton in Exclusive and Inclusive Charmless B
  decays

abstract:
  Within the Standard Model, CP rate asymmetries for $B\to K^-\pi^{+,0}$ could
reach 10%. With strong final state phases, they could go up to 20--30%, even
for $\bar K^0\pi^-$ mode which would have opposite sign. We can account for
$K^-\pi^{+}$, $\bar K^0\pi^-$ and $\phi K$ rate data with new physics enhanced
color dipole coupling and destructive interference. Asymmetries could reach
40--60% for $K\pi$ and $\phi K$ modes and are all of the same sign. We are
unable to account for $K^-\pi^0$ rate. Our inclusive study supports our
exclusive results.


title:
The $Q\bar{Q}$ Potential in the Color-Dielectric Formulation of the
  Transverse Lattice

abstract:
  The $Q\bar{Q}$ potential is calculated in the Color-Dielectric Formulation of
Transverse Lattice QCD. In such a formulation an effective potential is used to
enforce the $SU(N_c)$ symmetry of the link fields. This effective potential is
truncated at fourth order. Surprisingly, there is striking rotational
invariance in the ground state $Q\bar{Q}$ potential as well as in the first
hybrid mode.


title: Nonfactorizable Effects in Charmless B Decays and B Meson Lifetimes

abstract:
  Status of nonfactorizable effects in hadronic charmless B decays is reviewed.
Implications of new CLEO measurements on $B^0\to\pi^+\pi^-$ and $B\to\eta' K$
are discussed. Nonfactorizable effects due to color ocet 4-quark operators are
calculated using renormalization group improved QCD sum rules. The resultant
B-meson lifetime ratio $\tau(B^-)/\tau(B_d)$ agrees with experiment.


title:
Semirelativistic quark-antiquark potential, mass spectra and weak decays
  into excited states of heavy-light mesons

abstract:
  Relativistic properties of qqbar potentail, mass spectra of orbitally and
radially excited B and D mesons as well as semileptonic decays of B mesons to
orbitally excited D mesons are discussed in the framework of the relativistic
quark model based on the quasipotential approach.


title:
Small Instanton Contribution to the Axion Potential in Supersymmetric
  Models

abstract:
  Small size QCD instantons may spoil the axion solution to the strong CP
problem if QCD is not asymptotically free at high energy scales. We examine
this issue in supersymmetric models using a manifestly supersymmetric scheme to
compute the axion potential induced by small size instantons. Applying this
scheme for a class of illustrative models, it is found that the resulting high
energy axion potential is highly model-dependent, but suppressed by more powers
of the soft supersymmetry breaking parameters and/or of the other small mass
scales than what is expected based on a naive instanton graph analysis. Our
analysis suggests that the axion solution is stable against the small QCD
instanton effects in a wide class of supersymmetric models even when QCD is not
asymtotically free at high energy scales.


title:
The Operator Product Expansion, Non-perturbative Couplings and the
  Landau Pole: Lessons from the O(N) $\sigma$-Model

abstract:
  We obtain the operator product expansion of the self-energy in the O(N)
non-linear $\sigma$-model to all orders in the coupling and the large momentum,
and to next-to-leading order in 1/N. In the light of this result we discuss
recent suggestions that there may be additional power corrections from short
distances, associated with defining the coupling constant non-perturbatively.
The non-linear $\sigma$-model provides no evidence for such `non-standard'
power corrections. We also find that the OPE converges for sufficiently large
external momentum, presumably because there are no multi-particle thresholds at
arbitrarily high energies in the 1/N expansion.


title: Studying High Energy Final State Interactions by N/D Method

abstract:
  We discuss the final state interaction effects at high energies via a
multi-channel N/D method. We find that the 2 by 2 charge--exchange final state
interactions typically contribute an enhancement factor of a few times
$10^{-2}$ in the $B$ meson decay amplitudes, both for the real and the
imaginary part. We also make some discussions on the elastic rescattering
effects.


title: Fragmentation and Multifragmentation of 10.6A GeV Gold Nuclei

abstract:
  We present the results of a study performed on the interactions of 10.6A GeV
gold nuclei in nuclear emulsions. In a minimum bias sample of 1311 interac-
tions, 5260 helium nuclei and 2622 heavy fragments were observed as Au projec-
tile fragments. The experimental data are analyzed with particular emphasis of
target separation interactions in emulsions and study of criticalexponents.
Multiplicity distributions of the fast-moving projectile fragments are inves-
tigated. Charged fragment moments, conditional moments as well as two and three
-body asymmetries of the fast moving projectile particles are determined in
terms of the total charge remaining bound in the multiply charged projectile
fragments. Some differences in the average yields of helium nuclei and heavier
fragments are observed, which may be attributed to a target effect. However,
two and three-body asymmetries and conditional moments indicate that the
breakup mechanism of the projectile seems to be independent of target mass. We
looked for evidence of critical point observable in finite nuclei by study the
resulting charged fragments distributions. We have obtained the values for the
critical exponents gamma, beta and tau and compare our results with those at
lower energy experiment (1.0A GeV data). The values suggest that a phase
transition like behavior, is observed.


title:
CP violating asymmetries of b quarks and leptons in e^+e^- \to t\bar t
  and supersymmetry (review)

abstract:
  The distributions of the single decay b-quarks and leptons from e^+e^- \to
t\bar t assuming CP violation are reviewed. Different asymmetries, sensitive
independently to CP violation in the production and in the decay, and sensitive
to the real and imaginary parts of d^\gamma and d^Z are defined. The analytic
expressions are general and independent on the model of CP violation. In most
of them all phase space integrations are fulfilled analytically. Numerical
results in the MSSM with complex couplings are presented.