title: Field Theory and the Standard Model

abstract:
  The following 5 lectures are devoted to key ideas in field theory and in the
Standard Model.


title: Holder Inequalities and Bounds on the Masses of Light Quarks

abstract:
  QCD Laplace sum-rules must satisfy a fundamental (Holder) inequality if they
are to consistently represent an integrated hadronic cross-section. After
subtraction of the pion-pole, the Laplace sum-rule of pion currents is shown to
violate this fundamental inequality unless the up and down quark masses are
sufficiently large, placing a lower bound on the 1.0 GeV MS-bar running masses.


title:
Asymptotic Pade-Approximant Methods and QCD Current Correlation
  Functions

abstract:
  Asymptotic Pade-approximant methods are utilized to estimate the
leading-order unknown (i.e., not-yet-calculated) contributions to the
perturbative expansions of two-current QCD correlation functions obtained from
scalar-channel fermion and gluon currents, as well as from vector-channel
fermion currents. Such contributions to the imaginary part of each correlator
are polynomials of logarithms whose coefficients (other than the constant term
within the polynomial) may be extracted from prior-order contributions by use
of the renormalization-group (RG) equation appropriate for each correlator. We
find surprisingly good agreement between asymptotic Pade-approximant
predictions and RG-determinations of such coefficients for each correlation
function considered, although such agreement is seen to diminish with
increasing numbers of quark flavours. The RG-determined coefficients we obtain
are then utilized in conjunction with asymptotic Pade-approximant methods to
predict the RG-inaccessible constant terms of the leading-order unknown
contributions for all three correlators. The vector channel predictions lead to
estimates for the order $(\alpha_s^4)$ contribution to $R(s) \equiv[\sigma(e^+
e^- \to hadrons) / \sigma(e^+ e^- \to \mu^+ \mu^-)]$ for three, four, and five
flavours.


title: Where does Flavour Mixing come from?

abstract:
  We argue that flavour mixing, both in the quark and charged lepton sector, is
basically determined by the lightest family mass generation mechanism. So, in
the chiral symmetry limit when the up and down quark masses vanish, all the
quark mixing angles vanish. This mechanism is not dependent on the number of
quark-lepton families nor on any ``vertical'' symmetry structure, unifying
quarks and leptons inside a family as in Grand Unified Theories. Together with
a hypothesis of maximal CP violation, the model leads to a completely
predictive ansatz for all the CKM matrix elements in terms of the quark masses.
Some implications for neutrino masses and oscillations are briefly discussed.


title: Nonperturbative Determination of Heavy Meson Bound States

abstract:
  In this paper we obtain a heavy meson bound state equation from the heavy
quark equation of motion in heavy quark effective theory (HQET) and the heavy
meson effective field theory we developed very recently. The bound state
equation is a covariant extention of the light-front bound state equation for
heavy mesons derived from light-front QCD and HQET. We determine the covariant
heavy meson wave function variationally by minimizing the binding energy
$\bar{\Lambda}$. Subsequently the other basic HQET parameters $\lambda_1$ and
$\lambda_2$, and the heavy quark masses $m_b$ and $m_c$ can also be
consistently determined.


title: Probing Spontaneous CP-Violation in Supersymmetric Models via B-Decays

abstract:
  We study implications of spontaneous CP-violation in minimal susy models for
CP-asymmetries in rare $B,\bar B$-decays. In particular, we estimate
characteristic values of the angles of the unitarity triangle and show that
sizeable CP-violating effects result from $B-\bar B$ mixing only. Significant
deviations from the SM predictions are pointed out.


title:
Finite Quark Mass Effects in the Improved Ladder Bethe-Salpeter
  Amplitudes

abstract:
  We study the finite quark mass effects of the low-energy QCD using the
improved ladder Schwinger-Dyson and Bethe-Salpeter equations which are derived
in the manner consistent with the vector and axial-vector Ward-Takahashi
identities. The non-perturbative mass-independent renormalization allows us to
calculate the quark condensate for a non-zero quark mass. We explicitly show
that the PCAC relation holds. The key ingredients are the
Cornwall-Jackiw-Tomboulis effective action, the generalized Noether current and
the introduction of the regularization function to the Lagrangian. The
reasonable values of the pion mass, the pion decay constant and the quark
condensate are obtained with a rather large $\Lambda_{QCD}$. The pion mass
square and the pion decay constant are almost proportional to the current quark
mass up to the strange quark mass region. It suggests that the chiral
perturbation is applicable up to the strange quark mass region.
  We study the validity of the approximation often used in solving the
Bethe-Salpeter equations too.


title: NJL model with infrared confinement

abstract:
  We consider an extended Nambu--Jona-Lasinio (NJL) model for the light meson
sector of QCD where unphysical quark production thresholds are excluded by an
infrared cut-off on the momentum integration within quark loop diagrams. This
chiral quark model conserves the low energy theorems. The infrared cut-off is
fixed selfconsistently by the dynamically generated quark mass (quark
condensate). The masses and decay widths of the \sigma- and \rho-mesons are
described in the model.


title:
Anomalous Kinetics of Hard Charged Particles: Dynamical Renormalization
  Group Resummation

abstract:
  We study the kinetics of the distribution function for charged particles of
hard momentum in scalar QED. The goal is to understand the effects of infrared
divergences associated with the exchange of quasistatic magnetic photons in the
relaxation of the distribution function. We begin by obtaining a kinetic
transport equation for the distribution function for hard charged scalars in a
perturbative expansion that includes hard thermal loop resummation. Solving
this transport equation, the infrared divergences arising from absorption and
emission of soft quasi-static magnetic photons are manifest in logarithmic
secular terms. We then implement the dynamical renormalization group
resummation of these secular terms in the relaxation time approximation. The
distribution function (in the linearized regime) is found to approach
equilibrium as $\delta n_k(t) =\delta n_k(t_o) e^{-2\alpha T (t-t_o)
\ln[(t-t_o)\bar{\mu}]}$, with $\bar{\mu}\approx \omega_p$ the plasma frequency
and $\alpha =e^2/4\pi$. This anomalous relaxation is recognized to be the
square of the relaxation of the single particle propagator, providing a
generalization of the usual relation between the damping and the interaction
rate. The renormalization group approach to kinetics reveals clearly the time
scale $t_{rel} \approx (\alpha T \ln[1/\alpha])^{-1}$ arising from infrared
physics and hinges upon the separation of scales $t_{rel} >>\omega_p^{-1}$.


title: Associated Production of Upsilon and Weak Gauge Bosons at the Tevatron

abstract:
  We calculate the rate of production of W+Upsilon and Z+Upsilon at the
Tevatron. We find the cross sections at a center-of-mass energy of 1.8 TeV to
be roughly 450 pb for W+Upsilon and 150 pb for Z+Upsilon. The dominant
production mechanism involves the binding of a color-octet b-bbar pair into a
P-wave bottomonium state which subsequently decays into Upsilon. The purely
leptonic decay modes of Upsilon, W, and Z provide signatures with small
backgrounds. In Run I of the Tevatron, the number of events in the purely
leptonic decay channels before allowing for detector acceptances and
efficiencies should be about 500 for W+Upsilon and about 60 for Z+Upsilon. We
conclude that W+Upsilon events may be observable in the Run I data.


title: Perturbative Color Transparency in Electroproduction Experiments

abstract:
  We calculate quasi-exclusive scattering of a virtual photon and a proton or
pion in nuclear targets. This is the first complete calculation of ``color
transparency" and "nuclear filtering " in perturbative QCD. The calculation
includes full integrations over hard interaction kernels and distribution
amplitudes in Feynman -x fractions and transverse spatial separation space $b$.
Sudakov effects depending on $b$ and the momentum transfer $Q^2$ are included.
Attenuation of the hadronic states propagating through the medium is calculated
using an eikonal Glauber formalism. Nuclear correlations are included
explicitly. We find that the color transparency ratio is comparatively
insensitive to theoretical uncertainties inherent in perturbative formalism,
such as choice of infrared cutoff scales. However, the $Q^2$ dependence of the
transparency ratio is found to depend sensitively on the model of the
distribution amplitude, with endpoint-dominated models failing to be dominated
by short-distance. Color transparency experiments should provide an excellent
test of the underlying theoretical assumptions used in the pQCD calculations.


title:
Low Energy Quark-Gluon Processes from Experimental Data using the Global
  Colour Model

abstract:
  The Global Colour Model(GCM) of QCD is used to extract low energy quark-gluon
processes from experimental data. The resultant effective quark-quark coupling
correlator is compared with that of Jain and Munczek, and with the combined
lattice results of Marenzoni et al. and Skullerud, and with the two-loop form.
The results suggest that higher order gluon vertices are playing a role in
coupling quark currents. The success of the GCM is explained by an infrared
saturation effect.


title: Perturbative QCD study of the B-> K^* gamma decay

abstract:
  We apply the perturbative QCD factorization theorem developed recently for
nonleptonic heavy meson decays to the radiative decay $B\to K^*\gamma$. In this
formalism the evolution of the Wilson coefficients from the $W$ boson mass down
to the characteristic scale of the decay process is governed by the effective
weak Hamiltonian. The evolution from the characteristic scale to a lower
hadronic scale is formulated by the Sudakov resummation. Besides computing the
dominant contribution arising from the magnetic-penguin operator $O_7$, we also
calculate the contributions of four-quark operators. By fitting our prediction
for the branching ratio of the $B\to K^*\gamma$ decay to the CLEO data, we
determine the $B$ meson wave function, that possesses a sharp peak at a low
momentum fraction.


title: On Valence Gluons in Heavy Quarkonia

abstract:
  To include the explicit valence gluon degrees of freedom into spectroscopy of
the lowest states of heavy quarkonia, we consider, within an adiabatic model,
the properties of the lowest hybrid $\bar{Q}Qg$-mesons and estimate the effects
of their mixing with low-lying vector $\bar{c}c$-charmonia. The perspectives of
compatibility of the resulting picture with data are discussed.


title: An effective field theory of QCD at high density

abstract:
  We derive a (Wilsonian) effective field theory of QCD at finite density by
integrating out the states in the Dirac sea when the chemical potential
$\mu\gg\Lambda_{\rm QCD}$. The quark-gluon coupling is effectively
(1+1)-dimensional and the theory contains four-quark operators which become
relevant as we approach to the Fermi sea. By calculating the one-loop vacuum
polarization tensor in the effective theory, we find the electric gluons have a
screening mass, $M\sim g_s\mu$, while the static magnetic gluons are
unscreened. We then investigate the gap equations for color anti-triplet Cooper
pairs by including both gluon-exchange interactions and the marginal four-quark
interactions in the effective theory.


title: Summary of RADCOR 98

abstract:
  This summary is organized in four parts. In the first part results in the
electroweak theory are discussed, including precision tests of the Standard
Model. The second part deals with recent results in QCD, focusing on areas
where meaningful comparisons between theory and experiment are possible. The
third part summarizes some of the salient technical progress in studying
two-loop radiative effects in a variety of contexts, as well as progress made
in calculating radiative corrections in the LEP 200 region. Finally, in the
fourth part, a discussion of the effects of radiative corrections, both as a
result of new physics and in new energy regimes, is presented focusing on their
future experimental implications.


title: Gauge vortex dynamics at finite mass of bosonic fields

abstract:
  The simple derivation of the string equation of motion adopted in the
nonrelativistic case is presented, paying the special attention to the effects
of finite masses of bosonic fields of an Abelian Higgs model. The role of the
finite mass effects in the evaluation of various topological characteristics of
the closed strings is discussed. The rate of the dissipationless helicity
change is calculated. It is demonstrated how the conservation of the sum of the
twisting and writhing numbers of the string is recovered despite the changing
helicity.


title: Exploring Softly Broken SUSY Theories via Grassmannian Taylor Expansion

abstract:
  We demonstrate that soft SUSY breaking introduced via replacement of the
couplings of a rigid theory by spurion superfields has far reaching
consequences. Substituting these modified couplings into renormalization
constants, RG equations, solutions to these equations, fixed points, finiteness
conditions, etc., one can get corresponding relations for the soft terms by a
simple Taylor expansion over the Grassmannian variables. This way one can get
new solutions of the RG equations. Some examples including the MSSM, SUSY GUTs
and the N=2 Seiberg-Witten model are given.


title: The B_c Meson Lifetime in the Light--Front Constituent Quark Model

abstract:
  We present an investigation of 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 a
constituent quark model LF wave functions. The latter ones are derived via the
Hamiltonian LF formalism using as input the update versions of the constituent
quark 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. The
framework incorporates systematically 84 exclusive and 44 inclusive partial
rates corresponding to the underlying \bar{b}\to\bar{c} and c\to s quark
decays. Based on our approach we find\tau_{B_c}=0.59 \pm 0.06 ps where the
theoretical uncertainty is dominated by the uncertainty in the choice of LF
wave functions and the threshold values for the hadron continuum. For the
branching fractions of the B^+_c \to J/\psi\mu^+\nu_{\mu} and B_c^+\to
J/\psi\pi^+ decays we obtain 1.6 % and 0.1 %, respectively.


title: Color Superfluidity and Chiral Symmetry Breakdown in Dense QCD Matter

abstract:
  We describe the interplay of two nonperturbative phenomena which should take
place in the chirally invariant deconfined phase of QCD matter at finite
density and T=0: (i) Cooper-pair quark-quark ground-state condensation in
appropriate channels should yield exotic sorts of color superfluidity, and (ii)
quark-antiquark ground-state condensation should yield spontaneous breakdown of
chiral symmetry. We briefly review the main recent achievements in the subject,
and present the field-theory formalism which enables to deal with both above
mentioned types of condensates simultaneously.


title: Macroscopic quantum phases of a deconfined QCD matter at finite density

abstract:
  Formalism for a unified description of distinct superfluid phases of a
deconfined QCD matter at finite density together with the phase of
spontaneously broken chiral symmetry is presented. Dispersion laws of the
quasiquark excitations in both diamagnetic and ferromagnetic phases with
spontaneously broken chiral symmetry are exhibited explicitly.


title: Contact Interactions with Polarized Beams at HERA

abstract:
  The discovery potential of the HERA collider, with and without polarized
beams, for electron-quark contact interactions in neutral current scattering is
reviewed. The measurement of spin asymmetries in the polarized case could give
crucial information on the chiral structure of new interactions.


title:
The flavor changing top decay t-->c+sneutrino or sneutrino-->t+c(bar) in
  the MSSM without R-parity

abstract:
  Widths for the new flavor changing top quark decay t-->c+sneutrino or for the
reversed sneutrino decay sneutrino-->t+c(bar) are calculated in the MSSM
without R-parity conservation. For large \tan\beta, e.g., \tan\beta ~ m_t/m_b ~
40, Br(t-->c+sneutrino) > 10^{-5} or Br(sneutrino-->t+c(bar)) > 10^{-6} in a
relatively wide range of the supersymmetric parameter space as long as there is
more than one non-zero R-parity violating coupling. In the best cases, with a
typical squark mass around 100 GeV, we find that Br(t-->c+sneutrino) ~ 10^{-4}
- 10^{-3} or Br(sneutrino-->t+c(bar)) ~ 10^{-5} - 10^{-4}. For \tan\beta ~ O(1)
the corresponding branching ratios for both top or sneutrino decays are too
small to be measured at the LHC. Therefore, the decays t-->c+sneutrino or
sneutrino-->t+c(bar) appear to be sensitive to \tan\beta and may be detected at
the LHC. The branching ratios of the corresponding decays to an up quark
instead of a charm quark, e.g., t-->u+sneutrino or sneutrino-->t+u(bar), may
also be similar.


title: Low energy theorems and the Dirac operator spectral density in QCD

abstract:
  We discuss the behaviour of the spectral density of the massless Dirac
operator at the small eigenvalues and quark masses compatible with the
restrictions imposed by the low energy theorems in QCD. Sum rule for its
derivative over the quark mass is found.


title:
Spin Structure Function of the Virtual Photon Beyond the Leading Order
  in QCD

abstract:
  Polarized photon structure can be studied in the future polarized
$e^{+}e^{-}$ colliding-beam experiments. We investigate the spin-dependent
structure function of the virtual photon $g_1^{\gamma}(x,Q^2,P^2)$, in
perturbative QCD for $\Lambda^2 \ll P^2 \ll Q^2$, where $-Q^2$ ($-P^2$) is the
mass squared of the probe (target) photon. The analysis is performed to
next-to-leading order in QCD. We particularly emphasize the renormalization
scheme independence of the result.The non-leading corrections significantly
modify the leading log result, in particular, at large $x$ as well as at small
$x$. We also discuss the non-vanishing first moment sum rule of $g_1^\gamma$,
where ${\cal O}(\alpha_s)$ corrections are computed.


title:
Testing non-perturbative strong interaction effects via the Adler
  function

abstract:
  Based on the compilation of the available e^+e^- data, we present a
non-perturbative estimation of the Adler function derived from the
electromagnetic current correlator, and compare it with theoretical predictions
from perturbative QCD (pQCD). The comparison is presented for the Euclidean
region where pQCD is supposed to work best. We emphasize that such a comparison
only makes sense if one takes into account the exact mass dependence of the
perturbative predictions, which are available for the leading and next to
leading (two-loop) order. In order to have the correct physical mass dependence
in the evolution of the strong coupling as well, we utilize the MOM scheme
beta-function to two-loops calculated recently. Three-loop effects, which are
available as series expansions for low and high momentum transfer, are included
by using Pade improvement. We discuss possible constraints on non-perturbative
effects as suggested by the operator product expansion.


title: Study of T-odd Quark Fragmentation Function in $Z^0\to 2$-jet Decay

abstract:
  The first probe of the correlation of the T-odd one-particle fragmentation
function responsible for the left--right asymmetry of fragmentation of a
transversely polarized quark and an antiquark is done by using the 1991-95
DELPHI data for $Z\to 2$ jet decay. Integrated over the fraction of
longitudinal and transversal momenta, this correlation is of 2.5 ppm order,
which means order of 7% for the analyzing power. This makes us hope to use
certain effects in polarized DIS experiments for transversity measurement.


title:
$\gamma^*\gamma^*$ total cross-section in the dipole picture of BFKL
  dynamics

abstract:
  The total $\gamma^*\gamma^*$ cross-section is derived in the Leading Order
QCD dipole picture of BFKL dynamics, and compared with the one from 2-gluon
exchange. The Double Leading Logarithm approximation of the DGLAP cross-section
is found to be small in the phase space studied. Cross sections are calculated
for realistic data samples at the $e^+e^-$ collider LEP and a future high
energy linear collider. Next to Leading order corrections to the BFKL evolution
have been determined phenomenologically, and are found to give very large
corrections to the BFKL cross-section, leading to a reduced sensitivity for
observing BFKL.


title:
Effective $\Delta S=1$ weak chiral Lagrangian from the instanton-induced
  chiral quark model

abstract:
  We present the recent investigation of the $\Delta S = 1$ effective weak
chiral Lagrangian within the framework of the instanton-induced chiral quark
model. Starting from the effective four-quark operators, we derive the
effective weak chiral action by integrating out the constituent quark fields.
Employing the derivative expansion, we obtain the effective weak chiral
Lagrangian to ${\cal O} (p^4)$ order with low energy constants.


title: Heavy Majorana neutrinos in e+e- colliders

abstract:
  We investigate possibilities for detecting heavy Majorana neutrinos ($N$'s)
in $e^+e^-$ at LEP200 and future Linear Colliders. We concentrate on the
processes where the pairs of intermediate heavy $N$'s produce a clear signal of
total lepton number violation ($e^+e^- \to NN \to W^+l^-W^+l^{\prime -}$). Such
a signal is not possible if the heavy neutrinos are of Dirac nature. Our
approach is general in the sense that the intermediate $N$'s can be either on
shell or off shell. Discussion of the relative numerical importance of the $s$
and the $t+u$ channels of the $NN$ production is also included.


title: Bound States by the Spinless Salpeter Equation

abstract:
  In quantum theory, bound states are described by eigenvalue equations, which
usually cannot be solved exactly. However, some simple general theorems allow
to derive rigorous statements about the corresponding solutions, that is,
energy levels and wave functions. These theorems are applied to the prototype
of all relativistic wave equations, the spinless Salpeter equation.


title: Rotational Stability of Linear String Baryon Configuration

abstract:
  For the linear baryon string model with three massive points (three quarks)
connected sequentially by the relativistic strings the initial-boundary value
problem is stated and solved in general. This problem implies defining a
classical motion of the system on the base of given initial position and
initial velocities of string points. The given solution work reduces the
initial-boundary value problem for the considered model to the system of
ordinary differential equations that can be integrated numerically in general.
The examples of numerical simulation of the system motion are considered,
which, in particular, allow to answer to the old question about stability of a
flat uniform rotation of the linear string configuration.


title:
On Prospects for Exploration of Supersymmetry in Double Beta Decay
  Experiments

abstract:
  We analyze constraints on the parameters of the R-parity violating
supersymmetry which can be extracted from non-observation of the neutrinoless
nuclear double beta decay ($0\nu\beta\beta$) at a given half-life lower bound.
Our analysis covers a large class of phenomenologically viable R-parity
violating SUSY models. We introduce special characteristics: the SUSY
sensitivity of a $\beta\beta$ decaying isotope and the SUSY reach of a
$0\nu\beta\beta$ experiment. The former provides a physical criterion for a
selection of the most promising isotopes for SUSY searches and the latter gives
a measure of success for a $0\nu\beta\beta$ experiment in exploring the
R-parity violating SUSY parameter space. On this basis we discuss prospects for
exploration of supersymmetry in various $0\nu\beta\beta$ experiments.


title:
The strategy of regions for asymptotic expansion of two-loop vertex
  Feynman diagrams

abstract:
  General prescriptions for evaluation of coefficients at arbitrary powers and
logarithms in the asymptotic expansion of Feynman diagrams in the Sudakov limit
are discussed and illustrated by two-loop examples. Peculiarities connected
with evaluation of individual terms of the expansion, in particular, the
introduction of auxiliary analytic regularization, are characterized.


title:
Flavor SU(3) Symmetry and Factorization in B Decays to Two Charmless
  Vector Mesons

abstract:
  We first present a model-independent analysis using flavor SU(3) symmetry
with SU(3) breaking effects in $B$ decays to two charmless vector mesons ($VV$)
in the final state. In order to bridge the flavor SU(3) symmetry approach and
the factorization approach in $B \to VV$ decays, we explicitly show how to
translate each SU(3) amplitude into a corresponding amplitude in factorization.
Various decay modes, including $B \to K^* \phi$ which is so far the only $B \to
VV$ mode having some experimental evidence, are discussed in both the SU(3)
symmetry and factorization approaches. Within the generalized factorization
approximation, the flavor SU(3) amplitudes and SU(3) breaking effects are
numerically estimated as a function of the parameter $\xi \equiv 1/ N_c$ ($N_c$
the effective number of color).


title:
Bounds and Implications of Neutrino Magnetic Moments from Atmospheric
  Neutrino Data

abstract:
  The neutral current effects of the future high statistics atmospheric
neutrino data can be used to distinguish the mechanisms between a $\nu_\mu$
oscillation to a tau neutrino or to a sterile neutrino. However, if neutrinos
possess large diagonal and/or transition magnetic moments, the neutrino
magnetic moments can contribute to the neutral current effects which can be
studied by the single $\pi^0$ production events in the Super-K data. This
effect should be included in the future analyses of atmospheric data in the
determination of $\nu_\mu$ to tau or sterile neutrino oscillation.


title: Nuclear Shadowing in Neutrino Deep Inelastic Scattering

abstract:
  We discuss effect of nuclear shadowing in neutrino deep-inelastic scattering
in terms of non perturbative parton model. We found that for small Bjorken $x$
and large $Q^2$ the structure function $F_3$ is shadowed in nuclei about two
times as stronger as $F_2$. The underlying reason and phenomenological aspects
of this observation are discussed.


title: Microwave background anisotropies in quasiopen inflation

abstract:
  Quasiopenness seems to be generic to multi-field models of single-bubble open
inflation. Instead of producing infinite open universes, these models actually
produce an ensemble of very large but finite inflating islands. In this paper
we study the possible constraints from CMB anisotropies on existing models of
open inflation. The effect of supercurvature anisotropies combined with the
quasiopenness of the inflating regions make some models incompatible with
observations, and severely reduces the parameter space of others. Supernatural
open inflation and the uncoupled two-field model seem to be ruled out due to
these constraints for values of $\Omega_0\lesssim0.98$. Others, such as the
open hybrid inflation model with suitable parameters for the slow roll
potential can be made compatible with observations.


title: Gamma photons from parametric resonance in neutron stars

abstract:
  Shock waves in cold nuclear matter, e.g. those induced by a collision of two
neutron stars, can generate a large number of gamma photons via parametric
resonance. We study the resonant production of gamma rays inside a shocked
neutron star and discuss the possible astrophysical consequences of this
phenomenon.


title: Charge asymmetry in two-Higgs doublet models

abstract:
  We discuss the features of a two-Higgs doublet model exhibiting a two stage
phase transition. At finite temperatures electric charge violating stationary
points are developed. In conjunction with {\em CP} violation in the Higgs or
the Yukawa sector, the phase transition to the charge conserving vacuum,
generates a net charge asymmetry $\Delta Q$, in the presence of heavy leptons,
which may be well above the astrophysical bounds put on $\Delta Q$ unless the
heavy leptons are sufficiently massive. This type of transition may be of
relevance for supersymmetric extensions of the Standard Model, since it shares
the same features, namely two Higgs doublets and similar {\em CP} violating
sources.


title: Constraints on the Higgs Sector from Processes Involving Photons

abstract:
  The Higgs sector of the Standard Model and of the Two Higgs Doublet
Extensions of SM, MSSM and the general 2HDM, can be tested in processes
involving photons. A short review of the corresponding results is presented.


title: Explorations of Compositeness

abstract:
  Some of the motivations for quark and lepton compositeness, and some problems
associated with present schemes, are noted. One model is discussed in which
quarks and leptons are taken as composites of spin-1/2 fermions $F$ with
charges $\pm 1/2$ and spinless bosons $\bar S$ with charges 1/6 and -1/2.


title:
Fermion masses, neutrino oscillations, and proton decay in the light of
  SuperKamiokande

abstract:
  Within the framework of unified gauge models, interactions responsible for
neutrino masses can also provide mechanisms for nucleon instability. We discuss
their implications concretely in the light of recent results on neutrino
oscillation from the SuperKamiokande collaboration. We construct a predictive
SO(10)-based framework that describes the masses and mixing of all quarks and
leptons. An overconstrained global fit is obtained, that makes five successful
predictions for quarks and charged leptons. The same description provides
agreement with the SuperK results on atmospheric neutrinos and supports a
small-angle MSW mechanism. We find that current limits on nucleon stability put
significant stress on the framework. Further, a distinctive feature of the
SO(10) model developed here is the likely prominence of the $\mu^+ K^0$ mode in
addition to the $\bar{\nu} K^+$ mode of proton decay. Thus improved searches in
these channels for proton decay will either turn up events, or force us outside
this circle of ideas.


title: All-Order Collinear Behavior in Gauge Theories

abstract:
  I give a proof, using the unitarity-based method, of the collinear
factorization of the leading-color contribution to gauge-theory amplitudes. The
proof also provides a concrete formula which can be used to compute the
associated splitting amplitudes.


title:
Can a light technipion be discovered at the Tevatron if it decays to two
  gluons?

abstract:
  In multiscale and topcolor-assisted models of walking technicolor, light,
spin-one technihadrons can exist with masses of a few hundred GeV; they are
expected to decay as rho_T -> W pi_T. For technirho masses ~200 GeV and
technipion masses ~100 GeV, the process pbar p -> rho_T -> W pi_T has a cross
section of about a picobarn at the Tevatron. We demonstrate the detectability
of this process with simulations appropriate to Run II conditions, for the
challenging case where the technipion decays dominantly into two gluons.


title: M-fluences on String Model Building

abstract:
  Common to many classes of three family SU(3)_C x SU(2)_L x U(1)_Y string
models are an additional anomalous U(1)_A and numerous, often fractionally
charged, exotic particles beyond the minimal supersymmetric standard model
(MSSM). I present one string model with both of these properties. Using this
model as an example, I show how sometimes (near) string scale vacuum
expectation values that are both D- and F-flat (to all orders in the
superpotential) can simultaneously break the anomalous U(1)_A and give heavy
mass to all phenomenologically dangerous exotic states, decoupling them from
the low energy spectrum. For this model, some anomaly cancelling directions
actually decouple all MSSM exotics, producing the MSSM as the effective field
theory just below the string scale. This model realizes Witten's conjecture of
possible equivalence between the string scale M_S and the MSSM unification
scale M_MSSM. Talk presented at CPT '98, Bloomington, Indiana, 6--8 November
1998


title: A natural solution of $\mu$ from the hidden sector

abstract:
  The $\mu$ parameter is calculated in supergravity models possessing the
$U(1)_A\times U(1)_R$ symmetry. In one natural model without a free mass
parameter below the Planck scale, the symmetry breaking scale is identified as
the hidden sector squark condensation scale.


title:
O(\alpha_s) QCD Corrections to Spin Correlations in $e^- e^+ \to t \bar
  t$ process at the NLC

abstract:
  Using a Generic spin basis, we present a general formalism of one-loop
radiative corrections to the spin correlations in the top quark pair production
at the Next Linear Collider, and calculate the O(\alpha_s) QCD corrections
under the soft gluon approximation. We find that: (a) in Off-diagonal basis,
the $O(\alpha_s)$ QCD corrections to $e_L^- e^+$ ($e_R^- e^+$) scattering
process increase the differential cross sections of the dominant spin component
$t_{\uparrow}\bar{t}_{\downarrow}$ ($t_{\downarrow}\bar{t}_{\uparrow}$) by
$\sim 30%$ and $\sim (0.1%-3%)$ depending on the scattering angle for
$\sqrt{s}=400 GeV$ and 1 TeV, respectively; (b) in {Off-diagonal basis}
(Helicity basis), the dominant spin component makes up 99.8% ($\sim 53%$) of
the total cross section at both tree and one-loop level for $\sqrt{s}=400 GeV$,
and the Off-diagonal basis therefore remains to be the optimal spin basis after
the inclusion of $O(\alpha_s)$ QCD corrections.


title:
Radiatively Induced Neutrino Masses and Large Higgs-Neutrino Couplings
  in the Standard Model with Majorana Fields

abstract:
  The Higgs sector of the Standard Model with one right-handed neutrino per
family is systematically analyzed. In a model with intergenerational
independent mixings between families, we can account for very light neutrinos
acquiring Majorana masses radiatively at the first electroweak loop level. We
also find that in such a scenario the Higgs coupling to the light-heavy
neutrinos and to the heavy-heavy ones may be remarkably enhanced with
significant implications for the production of these heavy neutrinos at high
energy colliders.


title: Reheating in the Presence of Inhomogeneous Noise

abstract:
  Explosive particle production due to parametric resonance is a crucial
feature of reheating in an inflationary cosmology. Coherent oscillations of the
inflaton field lead to a periodically varying mass in the evolution equation of
matter and gravitational fluctuations and often induce a parametric resonance
instability. In a previous paper (hep-ph/9709273) it was shown that homogeneous
(i.e. space independent) noise leads to an increase of the generalized Floquet
exponent for all modes, at least if the noise is temporally uncorrelated. Here
we extend the results to the physically more realistic case of spatially
inhomogeneous noise. We demonstrate - modulo some mathematical fine points
which are addressed in a companion paper - that the Floquet exponent is a non-
decreasing function of the amplitude of the noise. We provide numerical
evidence for an even stronger statement, namely that in the presence of
inhomogeneous noise, the Floquet exponent of each mode is larger than the
maximal Floquet exponent of the system in the absence of noise.


title: Reconstructing Neutrino Mass Spectrum

abstract:
  Reconstruction of the neutrino mass spectrum and lepton mixing is one of the
fundamental problems of particle physics. In this connection we consider two
central topics: (i) the origin of large lepton mixing, (ii) possible existence
of new (sterile) neutrino states. We discuss also possible relation between
large mixing and existence of sterile neutrinos.


title:
More and More Indirect Signals for Extra Dimensions at More and and More
  Colliders

abstract:
  It has been recently suggested by Arkani-Hamed, Dimopoulos and Dvali that
gravity may become strong at energies not far above the electroweak scale and
thus remove the hierarchy problem. Such a scenario can be tested at both
present and future accelerators since towers of Kaluza-Klein gravitons and
associated scalar fields now play an important phenomenological role. In this
paper we examine several processes for their sensitivity to a low scale for
quantum gravity including deep inelastic $ep$ scattering at HERA, high
precision low energy $\nu N$ scattering, Bhabha and Moller scattering at linear
colliders and both fermion and gluon pair production at $\gamma \gamma$
colliders.


title:
Quark-Lepton Mass Matrices with $U(1)\times Z_2 \times Z_2'$ Flavor
  Symmetry

abstract:
  The U(1) flavor symmetry explains the large mixing of neutrinos while it
leads to the unique texture for the quark mass matrices. It is remarked that
U(1) symmetric mass matrices have the phenomenological defects. In the quark
sector, the mixing $V_{ub}$ is predicted to be large compared with the expected
value $\l^4$ at the GUT scale. In the lepton sector, U(1) charges, which give a
large mixing in the neutrino sector, also lead to the large one in the charged
lepton sector. In the viewpoint of the flavor symmetry, this is an unpleasant
feature because the neutrino mass hierarchy is determined only by unknown
coefficients of ${\cal O}(1)$, and the near-maximal flavor mixing is not
guaranteed in the case of both large angle rotations. These defects disappear
by introducing additional discrete symmetries $Z_2\times Z_2'$. The $U(1)\times
Z_2\times Z_2'$ quark-lepton mass matrices are presented by taking account of
the recent data of atmospheric neutrinos and solar neutrinos.


title: The $\rho^{\pm}-\rho^0$ Mass Splitting Problem

abstract:
  It is discussed the problem of the $\rho^\pm-\rho^0$ mass splitting. It is
suggested to use the $\phi\to\rho\pi\to 3\pi$ decay to measure the
  $\rho^{\pm}-\rho^0$ mass splitting.


title: Chiral NN interactions in nuclear matter

abstract:
  We consider an effective field theory of NN system in nuclear medium. The
shallow bound states, which complicate the effective field theory analysis and
lead to the large scattering length in the vacuum case do not exist in matter.
We study whether the chiral expansion of the effective potential can be
truncated in such situation. The cutoff regularization is used to render the
solution of the Bethe-Goldstone equation finite. We show that the
next-to-leading order terms in the chiral expansion of the effective NN
potential can indeed be interpreted as corrections so that the truncation of
the expansion is justified. However, it is pointed out that it is still useful
to treat the problem nonperturbatively since it may allow the consideration of
the nuclear systems with the density smaller that the normal nuclear matter
one. The possible directions of constructing the chiral theory of NN
interaction in medium are outlined.


title:
Effective Classical Theory for Real-Time SU(N) Gauge Theories at High
  Temperature

abstract:
  We derive an effective classical theory for real-time SU($N$) gauge theories
at high temperature. By separating off and integrating out quantum fluctuations
we obtain a 3D classical path integral over the initial fields and conjugate
momenta. The leading hard mode contribution is incorporated in the equations of
motion for the classical fields. This yields the gauge invariant hard thermal
loop (HTL) effective equation of motion. No gauge-variant terms are generated
as in treatments with an intermediate momentum cut-off. Quantum corrections to
classical correlation functions can be calculated perturbatively. The 4D
renormalizability of the theory ensures that the 4D counterterms are sufficient
to render the theory finite. The HTL contributions of the quantum fluctuations
provide the counterterms for the linear divergences in the classical theory.


title: The limit $m_q \to 0$ of perturbative QCD

abstract:
  This treatment of power corrections (in a special case of Euclidean
asymptotic regimes and vacuum condensates) remains exemplary. Unlike
A.Mueller's 1985 "renormalon" paper, this trail-blazing Letter:
  1) was based on the correct mechanism of factorization for power corrections
(--> comments appended to the main text);
  2) used a method (which subsequently became Asymptotic Operation;
hep-ph/9703424 and refs. therein) that automatically yields exact diagrammatic
formulas for the coefficients of power corrections, which directly allow
non-perturbative operator interpretation (without any 'matchings');
  3) did not conjure irrelevant mathematical concepts (Borel summation) nor
introduce arbitrary hypotheses ("renormalons") to explain what is clear already
from careful analysis of diagrams (coefficients of power corrections are not
perturbatively calculable).
  Incidentally, January 4 is the birthday of Sir Isaac Newton whose example as
regards non-invention of arbitrary hypotheses proves so hard for theorists to
follow.


title: Double Beta Decay

abstract:
  We review the recent developments in the field of nuclear double beta decay,
which is presently an important topic in both nuclear and particle physics. The
mechanism of lepton number violation within the neutrinoless double beta decay
is discussed in context of the problem of neutrino mixing and the R-parity
violating supersymmetric extensions of the Standard model. The problem of
reliable determination of the nuclear matrix elements governing both
two-neutrino and neutrinoless modes of the double beta decay is addressed. The
validity of different approximation schemes in the considered nuclear structure
studies is analyzed and the role of the Pauli exclusion principle for a correct
treatment of nuclear matrix elements is emphasized. The constraints on
different lepton number violating parameters like effective electron neutrino
mass, effective right-handed weak interaction parameters, effective Majoron
coupling constant and R-parity violating SUSY parameters are derived from the
best presently available experimental limits on the half life of neutrinoless
mode of this process.


title: On the T-Odd Quark Fragmentation Function and on Transversal Handedness

abstract:
  The first probe of the correlation of the T-odd one-particle fragmentation
function responsible for the left--right asymmetry of fragmentation of a
transversely polarized quark is done by using the 1991-95 DELPHI data for $Z\to
2$-jet decay. Integrated over the fraction of longitudinal and transversal
momenta, this correlation is of 1.5% order, which means order of 13% for the
analyzing power.
  A rather large ($\approx 10%$) handedness transversal to the production plane
was observed in the diffractive production of ($\pi^-\pi^+\pi^-$) triples from
nuclei by the $40 GeV/c \pi^-$--beam. It was shown that the phenomenon has a
clear dynamic origin and resembles the single spin asymmetry behavior. All this
makes us hope to use this effects in polarized DIS experiments for transversity
measurement.


title: CPT- and B-Violation: The p-pbar Sector

abstract:
  The CPT symmetry of relativistic quantum field theory requires the total
lifetimes of particles and antiparticles be equal. Detection of pbar lifetime
shorter than tau_p > O(10^32) yr would signal breakdown of CPT invariance, in
combination with B-violation. The best current limit on tau_pbar, inferred from
cosmic ray measurements, is about one Myr, placing lower limits on
CPT-violating scales that depend on the exact mechanism. Paths to CPT breakdown
within and outside ordinary quantum mechanics are sketched. Many of the
limiting CPT-violating scales in pbar decay lie within the weak-to-Planck
range.


title: Nonleptonic charmless 2-body B decays in the perturbative QCD approach

abstract:
  With the generalized factorization approximation, we calculate the branching
ratios and CP asymmetries in B meson decays into two charmless pseudoscalar
mesons. We give a new estimation of the matrix elements of (S+P)(S-P) current
products with the PQCD method instead of equation of motion. We find that our
results are comparatively smaller than those in the literature.


title: Atmospheric Neutrino Oscillations in Three-Flavor Neutrinos. II

abstract:
  We analyze the atmospheric neutrino experiments of SuperKamiokande (535 days)
using the three-flavor neutrino framework with the mass hierarchy m_1 nearly
equal m_2 << m_3. We study the event ratios of sub-GeV, multi-GeV and upward
through-going muons zenith angle distributions. Taking into account the
atmospheric and terrestrial experiments, we obtain the allowed regions of mass
and mixing parameters \Delta m_{12}^2, sin^22\theta_{12}, \Delta m_{23}^2,
\theta_{13} and \theta_{23}. The mass parameter \Delta m^2_{23} is restricted
to 0.01eV^2-0.0002eV^2. For mixing parameters, there is no difference between
the large \theta_{12} angle solution and the small one, and
\theta_{13}<13degrees, 28degrees<\theta_{23}<37degrees and 53degrees<
\theta_{23}<62degrees for \Delta m_{23}^2=0.01eV^2, \theta_{13}<23degrees and
29degrees<\theta_{23}<61degrees for \Delta m_{23}^2=0.00eV^2, 4degrees<
\theta_{13}<22degrees and 38degrees<\theta_{23}<54degrees for \Delta m_{23}^2
=0.0002eV^2.


title: Axino-Neutrino Mixing in Gauge-Mediated Supersymmetry Breaking Models

abstract:
  When the strong CP problem is solved by spontaneous breaking of an anomalous
global symmetry in theories with gauge-mediated supersymmetry breaking, the
pseudo Goldstone fermion (the axino) is a good candidate of a light sterile
neutrino. Its mixing with neutrinos relevant for current neutrino experiments
can arise in the presence of R-parity violation. The realistic four neutrino
mass matrix is obtained when the see-saw mechanism is brought in, and an ansatz
for the right-handed neutrino mass is constructed.


title: Charged Higgs Associated Production with W at Linear Collider

abstract:
  We have calculated the cross section of the process $e^+e^- \to
W^{\pm}H^{\mp}$ at the linear collider in the supersymmetrical
two-higgs-doublet model. We find that the cross section decreases rapidly with
the increment of $\tan\beta$, and which can reach almost 1 fb for the favorable
parameters.


title: Perturbative Evolution and Regge Behaviour

abstract:
  The known analytic properties of the Compton amplitude at small $Q^2$ place
significant constraints on its behaviour at large $Q^2$. This calls for a
re-evaluation of the role of perturbative evolution in past fits to data.


title:
Correlator of topological charge densities at low $Q^2$ in QCD:
  connection with proton spin problem

abstract:
  Vacuum correlator of topological charge densities $\chi(q^2)$ at low $q^2$ in
QCD is discussed: its value $\chi(0)$ and first derivative $\chi'(0)$ at
$q^2=0$ and the contributions of pseudoscalar quasi-Goldstone bosons to
$\chi(q^2)$ at low $q^2$. The QCD sum rule \cite{1}, giving the connection of
$\chi'(0)$ (for massless quarks) with the part of the proton spin $\Sigma$,
carried by $u,d,s$ quarks, is presented. From the requirement of
selfconsistancy of the sum rule the values of $\chi'(0)$ and $\Sigma$ were
found. The same value of $\chi'(0)$ follows also from the experimental data on
$\Sigma$. The contributions of $\pi$ and $\eta$ to $\chi(q^2)$ are calculated
basing on low energy theorems. In such calculation the $\pi-\eta$ mixing,
expressed in terms of quark mass ratios is of importance.


title: Lifetimes of Xi_{bc}^{+} and Xi_{bc}^{0} baryons

abstract:
  Estimates of lifetimes and partial branching ratios for the baryons
$\Xi_{bc}^{+}$ and $\Xi_{bc}^{0}$ are presented using the inverse heavy quark
mass expansion technique carried out in the Operator Product Expansion
approach. We take into account both the perturbative QCD corrections to the
spectator contributions and, depending on the quark contents of hadrons, the
Pauli interference and weak scattering effects between the constituents, using
a potential model for the evaluation of the non-perturbative parameters.


title: Physics of hot and dense QCD

abstract:
  We give a brief review of modern theoretical understanding of the physics of
QCD at finite temperature and density. We concentrate in particular on the
properties of hadron gas at relatively small temperatures and discuss in
details the physics of the phase transition. We argue that the phase transition
in temperature is probably absent, but it can appear with a vengeance when
finite density effects are taken into account. We notice also that the
temperatures one can expect to reach at the heavy ion collider at RHIC are not
yet high enough for the perturbation theory in the QCD coupling constant to
work well.


title:
The Semiclassical Description of Tunneling in Scattering with Multiple
  Degrees of Freedom

abstract:
  We describe a computational investigation of tunneling at finite energy in a
weakly coupled quantum mechanical system with two degrees of freedom. We
compare a full quantum mechanical analysis to the results obtained by making
use of a semiclassical technique developed in the context of instanton-like
transitions in quantum field theory. This latter technique is based on an
analytic continuation of the degrees of freedom into a complex phase space, and
the simultaneous analytic continuation of the equations of motion into the
complex time plane.


title: Radiative corrections to the decays K_L^0->e^+e^- and K_L^0->mu^+mu^-

abstract:
  We calculate the rates and lepton (l) invariant mass distributions for decays
of the form 0^{-+}->l^+l^-\gamma, which are important radiative corrections to
the purely leptonic decays 0^{-+}->l^+l^-. Our approach uses the loop diagrams
which arise by including the two photon intermediate state and we retain the
imaginary parts of the loops - a radiative extension of the `unitarity bound'
for the process. These results are compared which those obtained using a model
in which the meson couples directly to the leptons.


title: Nearly Degenerate Neutrinos and Broken Flavour Symmetry

abstract:
  Theories with non-Abelian flavour symmetries lead at zeroth order to neutrino
degeneracy and massless charged fermions. The flavour symmetry is spontaneously
broken sequentially to give hierarchies $\Delta m_{atm}^2 \gg \Delta
m_{\odot}^2$ and $m_\tau \gg m_\mu \gg m_e$, and a misalignment of the vacuum
between neutrino and charged sectors gives large $\theta_{atm}$. Explicit
models are given which determine $\theta_{atm} = 45^\circ$. A similar
construction gives vacuum misalignment for the lighter generations and gives a
vanishing $\beta \beta_{0 \nu}$ rate, so that there is no laboratory constraint
on the amount of neutrino hot dark matter in the universe, and the solar mixing
angle is also maximal, $\theta_\odot = 45^\circ$.


title: The QCD Pomeron with Optimal Renormalization

abstract:
  It is shown that the next-to-leading order (NLO) corrections to the QCD
Pomeron intercept obtained from the BFKL equation, when evaluated in
non-Abelian physical renormalization schemes with BLM optimal scale setting do
not exhibit the serious problems encountered in the
$\overline{\mbox{MS}}$-scheme. A striking feature of the NLO BFKL Pomeron
intercept in the BLM approach is its rather weak dependence on the virtuality
of the reggeized gluon. This remarkable property yields an important
approximate conformal invariance. The results obtained provide an opportunity
for applications of NLO BFKL resummation to high-energy phenomenology.


title: Universal Pion Freeze-out Phase-Space Density

abstract:
  Results on the pion freeze-out phase-space density in sulphur-nucleus, Pb-Pb
and pion-proton collisions at CERN-SPS are presented. All heavy-ion reactions
are consistent with the thermal Bose-Einstein distrtibution f=1/(exp(E/T)-1) at
T~120 MeV, modified for expansion. Pion-proton data are also consistent with f,
but at T~180 MeV.


title:
Constraining the minimal supergravity model parameter tan(beta) by
  measuring the dilepton mass distribution at LHC

abstract:
  We study the dependence on $\tan\beta$ of the event kinematics of final
states with $e^+e^- /\mu^+\mu^- /e^{\pm}\mu^{\mp} + E_T^{\rm miss} + jets$, as
expected in $pp$ collisions at CERN LHC, within the framework of the minimal
supergravity model. With increase of $\tan\beta$, the third generation
sparticle masses $m_{\tilde{\tau}_1}$ and $m_{\tilde{b}_1}$ decrease due to the
increase of the tau and bottom Yukawa couplings. As a result, gluino, stop,
sbottom, chargino and neutralino decays to third generation particles and
sparticles are enhanced. With $\tan\beta$ rising, we observe a characteristic
change in the shape of the dilepton mass spectra in $e^+e^- /\mu^+\mu^-
+E_T^{\rm miss} + jets$ versus $e^{\pm}\mu^{\mp} + E_T^{\rm miss} + jets$ final
states, reflecting the presence of the decays $\tilde{\chi}_2^0\to
\tilde{\ell}_{L,R}^{\pm}\ell^{\mp}\to \tilde{\chi}_1^0 \ell^+\ell^-,
\tilde{\chi}_2^0\to \tilde{\chi}_1^0 \ell^+\ell^-$ and $\tilde{\chi}_2^0\to
\tilde{\tau}^{\pm}_1\tau^{\mp}\to \tilde{\chi}_1^0 \tau^+ \tau^-$,
$\tilde{\chi}_2^0\to \tau^+ \tau^- \tilde{\chi}_1^0$, respectively. We exploit
this effect for constraining the value of $\tan\beta$.


title:
Nonperturbative QCD corrections to the effective coefficients of the
  four-Fermi operators

abstract:
  We calculate the leading nonperturbative contributions to the effective
Wilson coefficient of the four-fermion operators arising from the QCD penguin,
and we demonstrate how the usual perturbative one loop contribution is
augmented by nonperturbative condensates. These corrections, which are obtained
by quark and gluon condensate insertions into the quark loops, enter at the
next-to-leading logarithm precision.
  Our results indicate for the charmed quark loop that the gluon condensate
contribution is quite sensitive to the momentum transfer to the quark-antiquark
pair.


title: QCD factorization in gamma* gamma -> pi pi and gamma* N -> pi pi N

abstract:
  Exclusive two-pion production near threshold in the collision of a highly
virtual photon with a real one offers a new possibility to unravel the partonic
content of hadrons. We explain the dynamics of this regime, i.e. the separation
of the amplitude in terms of partonic diagrams computable in QCD perturbation
theory and generalized distribution amplitudes, which are nonperturbative
functions describing the exclusive transition of a parton pair into two
hadrons. The same quantities also appear in gamma* N -> pi pi N in the
kinematical regime where the momentum transfer of the nucleon and the invariant
mass of the pion pair are both small; this allows to extend the QCD analysis of
exclusive rho electroproduction outside the resonance region of the two
produced pions.


title:
Quarks, Leptons as Fermion-Boson Composite Objects and Flavor-Mixings by
  Substructure Dynamics

abstract:
  A fermion-boson-type composite model for quarks and leptons is proposed.
Elementary fields are only one kind of spin-1/2 and spin-0 preon. Both are in
the global supersymmetric pair with the common electric charge of e/6 and
belong to the fundamental representations of (3,2,2) under the spontaneously
unbroken SU(3)_C*SU(2)_L*SU(2)_R gauge symmetry induced necessarily by the
concept of ``Cartan connection'' equipped with ``Soldering Mechanism''. Preons
are composed into subquarks which are ``intermediate clusters'' towards quarks
and leptons. The mechanism of making higher generations is obtained by adding
neutral scalar subquark composed of a preon-antipreon pair in the 3-state of
SU(2)_{L,R}. This model predicts the CKM matrix elements :
|V_{ts}|=2.6*10^{-2}},|V_{td}|=1.4*10^{-3}; the neutral pseudoscalar meson mass
differences : {Delta}M_D\approx10^{-14} GeV, {Delta}M_{B_s}\approx10^{-11}
GeV,{Delta}M_{T_u}\approx10^{(-10\sim{-9})} GeV and
{\Delta}M_{T_c}\approx10^{(-8\sim{-7})} GeV; the phases of CP violation :
{theta}_K={\theta}_D={\theta}_{B_s}={\theta}_{T_c}
\simeq(1/2){\theta}_{B_d}\simeq(1/2){\theta}_{T_u}.This model also suggests
that {\Delta}M^2\approx10{(-8\sim{-7})}eV^2 with large mixing angle in
(\nu_e,\nu_{\mu})-oscillation.


title:
Field Redefinitions and Wave Function Renormalization to $O(p^4)$ in
  Heavy Baryon Chiral Perturbation Theory

abstract:
  Mass- and wave-function renormalization is calculated to order $p^4$ in heavy
baryon chiral perturbation theory. Two different schemes used in the literature
are considered. Several technical issues like field redefinitions,
non-transformation of sources as well as subtleties related to the definition
of the baryon propagator are discussed. The nucleon axial-vector coupling
constant $g_A$ is calculated to order $p^4$ as an illustrative example.


title: Leptogenesis And Inflation

abstract:
  In this talk, we studied the implication of the constraint on the reheating
temperature coming from the gravitino problem on models of leptogenesis. We
point out that in supersymmetric extensions of the standard model, all existing
models of neutrino masses and leptogenesis, except the one with right-handed
singlet neutrinos are ruled out for a large range of the gravitino mass.


title: Top Squark Effects on Higgs Boson Production and Decays at the LHC

abstract:
  In the Minimal Supersymmetric Standard Model, one of the scalar top quarks
can be relatively light and its couplings to Higgs bosons strongly enhanced. I
will discuss two consequences of this feature: 1) the effects of scalar top
loops on the main production mechanism of the lightest Higgs boson at the LHC,
the gluon-fusion mechanism $gg \to h$, and on the important decay channel into
two photons $h \to \gamma \gamma$; and 2) the production of the light Higgs
particle in association with top-squark pairs at proton colliders, $pp \to
\tilde{t}_1 \tilde{t}_1 h$.


title: Photoproduction of $\psi'$ as a Test of Color-Octet Model

abstract:
  We have calculated the cross section of $\psi'$ photoproduction at
small-$p_{T}$ regions in polarized $\gamma p$ collisions for testing the
color-octet model, which is based on NRQCD factorization formalism. We show
that the measurement of the two-spin asymmetry of this process might be
effective to constrain the value of NRQCD matrix elements.


title:
Constraints on Hadronic Spectral Functions From Continuous Families of
  Finite Energy Sum Rules

abstract:
  Hadronic tau decay data is used to study the reliability of various finite
energy sum rules (FESR's). For intermediate scales (of order 2-3 GeV^2), those
FESR's with weights s^k are found to have significant errors, whereas those
with weights having a zero at the juncture (s=s_0) of the cut and circular part
of the contour work very well. It is also shown that a combination of two such
sum rules allows rather strong constraints to be placed on the hadronic
spectral function without sacrificing the excellent agreement between OPE and
hadronic representations. The method then is applied to the strangeness -1 and
pseudoscalar isovector channels, where it is shown to provide novel constraints
on those ansatze for the unmeasured continuum parts of the spectral functions
employed in existing extractions of m_u+m_d, m_s. The continuum ans\"atz in the
latter channel, in particular, is shown to produce a rather poor match to the
corresponding OPE representation, hence re-opening the question of the value of
the light quark mass combination m_u+m_d.


title: Barions as Solitons in Quantum SU(2) Skyrme Model

abstract:
  This paper is a PhD thesis defended at Institute of Theoretical Physics and
Astronomy on 18 December, 1998. The following (abbreviated) statements
represent the main results of the work:
  1.Each of SU(2) representation j yields the different quantum Lagrangian
density. As a consequence, theoretical observables depend on representation j
which can be treated as a new phenomenological parameter. 2.Quantum chiral
solitons exist and possess asymptotic behaviour consistent with the massive
Yukawa field fall. The asymptotic shape and PCAC relation leads to the correct
asymptotic equation coinciding with contribution of explicitly broken term. 3.A
nucleon and \Delta_{33}-resonance are the only stable states for irreducible
representations j=3/2 and j=2. Unphysical tower of states l_{spin} =l_{isospin}
is, therefore, terminated by choosing the appropriate SU(2) representations.
4.Higher spin l> 1/2 quantum states are not "spherically symmetric". The
Hamiltonian density function depends on the polar angle theta. 5.Each of the
spin-isospin state yields the different range of realizable values of the
parameter e. 6.A very good agreement with experimental data is obtained for
axial coupling constant g_A in higher representations of SU(2), the problem
being previously unsolved by using various extensions of the model in the
fundamental representation of SU(2). 7.The basic quantum Skyrme model provides
considerable improvements in nucleon magnetic momenta and, especially, in
neutron charge density distribution.


title:
Atmospheric and Solar neutrinos in the light of the SuperKamiokande
  results

abstract:
  The hierarchy $\Delta m^2_{atm} \gg \Delta m^2_\odot$ and the large
$\theta_{23}$ mixing angle, as suggested by neutrino oscillation experiments,
can be accounted for by a variety of lepton flavour models. A dichotomy
emerges: i) Models were all neutrino masses are bounded by $m_{atm}\equiv
(\Delta m^2_{atm})^{1/2}\approx 0.03 eV$; ii) Models of quasi-degenerate
neutrinos. It is shown how these different patterns of neutrino masses may
arise from different lepton flavour symmetries. Physical implications are
discussed in the various cases.


title:
Amplification of hypercharge electromagnetic fields by a cosmological
  pseudoscalar

abstract:
  If, in addition to the standard model fields, a new pseudoscalar field exists
and couples to hypercharge topological number density, it can exponentially
amplify hyperelectric and hypermagnetic fields in the symmetric phase of the
electroweak plasma, while coherently rolling or oscillating. We present the
equations describing the coupled system of a pseudoscalar field and hypercharge
electromagnetic fields in the electroweak plasma at temperatures above the
electroweak phase transition, discuss approximations to the equations, and
their validity. We then solve the approximate equations using assorted
analytical and numerical methods, and determine the parameters for which
hypercharge electromagnetic fields can be exponentially amplified.


title: Neutrino Mixings and Fermion Masses in Supersymmetric SU(5)

abstract:
  We consider neutrino mixings in supersymmetric SU(5) supplemented by a U(1)
flavor symmetry. In particular, we show how bi-maximal neutrino mixings can be
realized. Two scenarios for implementing the small mixing angle MSW solution,
with one involving a sterile state $\nu_s$ and maximal $\nu_{\mu}-\nu_s$ mixing
to resolve the atmospheric anomaly, are also discussed. Finally, a new
mechanism for eliminating the asymptotic relations $m^{(0)}_{\mu} =m^{(0)}_s$
and $m^{(0)}_e=m^{(0)}_d$, while retaining $m^{(0)}_{\tau}=m^{(0)}_b$, is
presented. It employs `matter' multiplets in the $15+\bar{15}$ of SU(5), and is
consistent with the various oscillation scenarios, as well as with the
unification at $M_{GUT}$ of the three gauge couplings.


title:
Gluon Virtuality and Heavy Sea Quark Contributions to the Spin-Dependent
  g_1 Structure Function

abstract:
  We analyze the quark mass dependence of photon gluon fusion in polarized deep
inelastic scattering for both the intrinsic and extrinsic gluon distributions
of the nucleon. We calculate the effective number of flavors for each of the
heavy and light quark photon gluon fusion contributions to the first moment of
the spin-dependent structure function $g_1(x)$.


title:
Nearly Degenerate Mass and Bi-maximal Mixing of Neutrinos in the SO(3)
  Gauge Model of Leptons

abstract:
  A realistic scheme for masses and mixing of leptons is investigated in the
model with gauged SO(3) lepton flavor symmetry. Within this scheme, a nearly
`bi-maximal' neutrino mixing pattern with maximal CP-violating phase is found
to be the only possible solution for reconciling both solar and atmospheric
neutrino flux anomalies. Three Majorana neutrino masses are nearly degenerate
and allow to be large enough to play a significant cosmological role. Lepton
flavor-violating effects via SO(3) gauge interactions can be as large as the
present experimental limits. Masses of the SO(3) gauge bosons are bounded to be
above 24 TeV when taking the SO(3) gauge boson mixing angle $\theta_{F}$ and
coupling constant $g'_{3}$ to be the same as those ($\theta_{W}$ and $g$) in
the electroweak theory.


title: The Minimal Supersymmetric Standard Model: Group Summary Report

abstract:
  CONTENTS: 1. Synopsis, 2. The MSSM Spectrum, 3. The Physical Parameters, 4.
Higgs Boson Production and Decays, 5. SUSY Particle Production and Decays, 6.
Experimental Bounds on SUSY Particle Masses, 7. References.


title:
Top-quark condensate at finite temperature and electroweak symmetry
  restoration

abstract:
  The gap equation at finite temperature in the top-quark condensate scheme of
electroweak symmetry breaking is proved to have the identical form in both the
imaginary and the real time formalism of thermal field theory. By means of the
gap equation, combined with the basic relation to define the vacuum expectation
value $v$ of the effective Higgs field, we analyse the dependence on
temperature T and chemical potential $\mu$ of the dynamical top-quark mass as
the order parameter characteristic of symmetry breaking, and obtain the $\mu-T$
criticality curve for symmetry restoration. We find out that the critical
temperature $T_{c}=2v$ for $\mu=0$ and the critical chemical potential
$\mu_c=2\pi v/\sqrt{3}$ for T=0. When $\mu=0$, the top-quark mass near $T_c$
has the leading ${(T_c^2-T^2)}^{1/2}$ behavior with an extra factor dependent
on temperature $T$ and the momentum cut-off $\Lambda$. However, it is generally
argued that the symmetry restoration at $T\geq T_c$ is still a second-order
phase transition.


title: Electroweak Lepton-Lepton and Lepton-Antilepton Bound States

abstract:
  In model independent way we consider the possibility of the existence of
fermion-antifermion, fermion-fermion bound states which appear due to $\gamma,
Z^0(W^{\pm}$-bosons and scalar, pseudoscalars exchanges including radiative
corrections. Our consideration includes the case where at least one particle in
the bound state is Majorana fermion or scalar.This paper considers various
types of bound states of particles contained in various extensions of the
Glashow-Weinberg -Salam model. We calculate long-range forces induced by
photonic, gluonic and fermionic loop corrections in scalar (pseudoscalar)
exchange.


title: Photoproduction of heavy quarks at HERA

abstract:
  Present status and prospects of heavy quark photoproduction studies at HERA
are reviewed.


title: Cosmological Consequences of Superconducting String Networks

abstract:
  We consider the cosmological consequences of a network of superconducting
cosmic strings. For strong enough current the period of friction domination
never ends. Instead a plasma scaling solution is reached. We demonstrate that
this gives rise to a very different cosmology than the usual horizon scaling
solution. In particular the string network gives rise to adistinct imprint on
the microwave sky, giving non-Gaussian features on much smaller angular scales.
It also gives rise to a filament structure in string wakes. Because of the
presence of the string magnetocylinder, the string magnetic field cannot create
a primordial magnetic field. Similarly, it evades nucleosynthesis constraints.
We also show that strings formed at the supersymmetry breaking scale can create
the required baryon asymmetry of the universe.


title: Cosmic Strings in Realistic Particle Physics Theories and Baryogensis

abstract:
  Grand unified theories can admit cosmic strings with fermion zero modes. Such
zero modes result in the string being current-carrying and the formation of
stable remnants, vortons. However, the string zero modes do not automaticall
survive subsequent phase transitions. In this case the vortons dissipate. It is
possible that the dissipating cosmic vortons create the observed baryon
asymmetry of the universe. We show that fermion zero modes are an automatic
consequence cosmic strings in supersymmetric theories. Since supersymmetry is
not observed in nature, we consider possible supersymmetry breaking terms. Some
of these terms result in the zero modes being destroyed. We calculate the
baryon asymmetry generated by the consequent dissipating cosmic vortons. If the
supersymmtry breaking scale is high enough, then the dissipating cosmic vortons
could account for the observed baryon asymmetry.


title:
FCNC transitions $c\to u\gamma$ and $s\to d\gamma$ in $B_c\to
  B_u^*\gamma$ and $B_s\to B_d^*\gamma$ decays

abstract:
  We propose the $B_c\to B_u^*\gamma$ decay as the most suitable probe for the
flavour changing neutral transition $c\to u\gamma$. We estimate the short and
long distance contributions to this decay within the standard model and we find
them to be comparable; this is in contrast to radiative decays of $D$ mesons,
that are completely dominated by the long distance contributions. Since the
$c\to u\gamma$ transition is very sensitive to the physics beyond the standard
model, the standard model prediction $Br(B_c\to B_u^*\gamma)\sim 10^{-8}$
obtained here opens a new window for future experiments. The detection of
$B_c\to B_u^*\gamma$ decay at branching ratio well above $10^{-8}$ would signal
new physics. In addition we study the $s\to d\gamma$ transition in $B_s\to
B_d^*\gamma$ decay and we find it to be dominated by the long distance
contribution. We use the Isgur-Scora-Grinstein-Wise (ISGW) constituent quark
model for the calculation of these decays.


title: Jacobi evolution of structure functions: convergence and stability

abstract:
  The Jacobi evolution method has been widely used in the QCD analysis of
structure function data. However a recent paper claims that there are serious
problems with its convergence and stability. Here we briefly review the
evidence for the adequate convergence of the method; and show that there are
errors in the above paper which undermine its conclusions.


title:
Solar and Atmospheric Neutrino Oscillations from Bilinear R-Parity
  Violation

abstract:
  We discuss general predictions for neutrino masses and mixing angles from R
parity violation in the Minimal Supersymmetric Standard Model. If the soft
supersymmetry breaking terms are flavor blind at short distance, then the
leptonic analogue of the CKM matrix depends on only two real parameters, which
are completely determined by fits to solar and atmospheric neutrino
oscillations. Either the small angle MSW, large angle MSW, or ``just-so''
solutions to the solar neutrino problem are allowed, although the large angle
MSW solution requires substantial fine-tuning. The latter two cases require
significant $\nu_\mu\to\nu_e$ oscillations of atmospheric neutrinos. We present
a model which could explain bilinear R parity violation as a consequence of
spontaneous symmetry violation by a dynamical supersymmetry breaking sector.
The decay length and branching ratios of the LSP are estimated.


title: Extended chiral Group and Scalar Diquarks

abstract:
  We introduce extended chiral transformation, which depends both on
pseudoscalar and diquark fields as parameters and determine its group
structure. Assuming soft symmetry breaking in diquark sector, bosonisation of a
quasi-Goldstone $ud$-diquark is performed. In the chiral limit the $ud$-diquark
mass is defined by the gluon condensate, $m_{ud}\approx 300 MeV$. The diquark
charge radius is $<r^2_{ud}>^{1/2}\approx 0.5 fm$. We consider also the flavour
triplet of scalar diquarks $(ud)$, $(us)$ and $(ds)$ together with pseudoscalar
mesons and calculate diquark masses and decay constants in terms of meson
parameters and the gluon condensate.


title: Erraticity Analysis of Soft Production by ECOMB

abstract:
  Event-to-event fluctuations of the spatial patterns of the final states of
high-enery collisions, referred to as erraticity, are studied for the data
generated by a soft-interaction model called ECOMB. The moments $C_{p,q}$ do
not show simple power-law dependences on the bin size. New measures of
erraticity are proposed that generalizes the bin-size dependence. The method
should be applied not only to the soft production data of NA22 and NA27 to
check the dynamical content of ECOMB, but also to other collision processes,
such as $e^+e^-$ annihilation and heavy-ion collisions.


title:
Determination of the dynamically generated Yukawa coupling in
  supersymmetric QCD

abstract:
  The strength of the dynamically generated Yukawa coupling among composite
fields is calculated. The system of N=1 supersymmetric SU(2) gauge theory with
massive three flavors is considered as an example. We use the techniques of
"integrating in" the gluino-gluino bound state in the low energy effective
theory and the instanton calculation and Shifman-Vainshtein-Zakharov sum rule
(QCD sum rule) in the fundamental theory. The obtained value of the Yukawa
coupling is of the order of unity. The method which is developed in this paper
can be applied to the other supersymmetric gauge theories.


title:
Deep Inelastic Scattering with a Tagged Photon: QED Corrections for the
  $\Sigma$ Method

abstract:
  After a brief review of the kinematics of deep inelastic scattering (DIS)
within the so-called $\Sigma$ method, we derive the necessary formulae for the
treatment of QED radiative corrections to DIS originating from hard photon
radiation. The results are applied to a calculation of the corrections to DIS
with a tagged photon with next-to-leading logarithmic accuracy under HERA
conditions. It turns out that the next-to-leading order corrections are quite
important for the $\Sigma$ method. We also discuss the dependence of the
corrections on the longitudinal structure function of the proton, $F_L$, in the
region of low $Q^2$ and moderate $x$.


title: Highlight of Dubna-SPIN97 Workshop

abstract:
  A summary of the Workshop on High Energy Spin Physics (Dubna-SPIN97), Dubna,
7-12 July 1997, is given.


title:
A supersymmetry extension of the standard model with bilinear R parity
  violation

abstract:
  The minimum supersymmetric standard model with bilinear R-parity violation is
studied systematically. Considering low-energy supersymmetry, we examine the
structure of the bilinear R-parity violating model carefully. We analyze the
mixing such as Higgs bosons with sleptons, neutralinos with neutrinos and
charginos with charged leptons in the model. Possible and some important
physics results such as the lightest Higgs may heavy than the weak Z-boson at
tree level etc are obtained. The Feynman rules for the model are derived in
$'$t Hooft- Feynman gauge, which is convenient if perturbative calculations are
needed beyond the tree level.


title: Pionic coupling constants of heavy mesons in the quark model

abstract:
  We analyse pionic couplings of heavy mesons combining PCAC with the
dispersion quark model to calculate the relevant transition form factors.
Ground states and radial excitations are considered. For the ground state
coupling constants the values $\hat g=0.5\pm0.02$ in the heavy quark limit,
$g_{B^*B\pi}=40\pm 3$, $g_{D^*D\pi}=16\pm 2$ are obtained. A sizeable
suppression of the coupling constants describing the pionic decays of the
radial excitations is observed.


title: Rare Kaon Decays and CP Violation

abstract:
  Rare kaon decays are an important testing ground of the electroweak flavor
theory: They can provide new signals of CP-violating phenomena. The interplay
of long-distance QCD effects in strangeness-changing transitions can be
analyzed with Chiral Perturbation Theory techniques. In particular, two rare
kaon decays are analyzed: The first decay, K_L -> pi0 e+e-, is being searched
for as a signal of direct Delta S = 1 CP violation. We provide a thorough
updating of the analysis of the three components of the decay: 1) Direct CP
violation, 2) CP violation through the mass matrix and 3) CP-conserving
(two-photon) contributions. First the chiral calculation of the K_S -> pi0 e+e-
rate is updated to include recent results on the nonleptonic amplitude. Then we
systematically explore the uncertainties in this method. The CP-conserving
amplitude remains somewhat uncertain, but present indications are such that
there may be a sizable CP-violating asymmetry in the e+, e- energies from the
interference of CP-conserving and CP-violating amplitudes. This may potentially
be useful in determining whether direct CP violation is present. The second
decay, K_L -> pi0 gamma e+e-, which occurs at a higher rate than the
nonradiative process K_L -> pi0 e+e-, can be a background to CP violation
studies using the latter reaction. The leading order chiral loop contribution
to K_L -> pi0 gamma e+e- is completely calculable.


title:
A new approach for the vertical part of the contour in thermal field
  theories

abstract:
  A lot of work has been devoted in the past to understand the role of vertical
branch of the time path in thermal field theories, and in particular to see how
to deal with it in the real-time formalism. Unlike what is commonly believed, I
emphasize on the fact that the vertical part of the path contributes to
real-time Green's functions, and I prove that this contribution is taken into
account simply by the substitution $n(\omega_{\boldsymbol k})\to n(|k_o|)$ in
the real time Feynman rules. This new proof is based on very simple algebraic
properties of the contour integration.


title: Analysis of the Three-Body $B \to D^+ D^- \pi^0$ Decay

abstract:
  The decay process $B\to D^+ D^- \pi^0$ is an interesting channel for the
investigation of CP violating effects in the $b-$ sector. We write down a decay
amplitude constrained by a low-energy theorem, which also includes the
contribution of resonant $S-$ and $P-$wave beauty and charmed mesons, and we
determine the relevant matrix elements in the infinite heavy quark mass limit,
assuming the factorization ansatz. We estimate the rate of the decay: ${\cal
B}(B \to D^+ D^- \pi^0)\simeq 1 \times 10^{-3}$. We also analyze the
time-independent and time-dependent differential decay distributions,
concluding that a signal for this process should be observed at the
B-factories. Finally, we give an estimate of the decay rate of the
Cabibbo-favoured process $B\to D^+ D^- K_S$.


title: CP Asymmetries in B_s Decays and Spontaneous CP violation

abstract:
  We study possible effects of new physics in CP asymmetries in two-body $B_s$
decays in left-right models with spontaneous CP violation. Considering the
contributions of new CP phases to the $B_s$ mixing as well as to the penguin
dominated decay amplitudes we show that, with the present constraints, large
deviations from the standard model predictions in CP asymmetries are allowed in
both cases. Detection of the new physics can be done by measuring non-zero
asymmetries which are predicted to vanish in the standard model or by comparing
two measurements which are predicted to be equal in the standard model. In
particular, we show that the measurement of the CKM angle $\gamma$ in
electroweak penguin dominated processes $B_s^0\to\rho^0\eta^{(')}, \rho^0\phi$
can largely be affected by the new physics.


title: Couplings of pions to higher positive parity heavy mesons

abstract:
  We evaluate the couplings of pions in the transitions of positive parity
heavy mesons, (1+,2+) and (0+,1+), to negative parity ones (0-,1-) using a
technique which is not limited to the soft-pion limit. This is made through a
constituent quark-meson model (the CQM model) where the amplitudes are obtained
by quark loops with mesons on the external lines. The results are in good
agreement with experimental data.


title: Diffractive S and D-wave vector mesons in deep inelastic scattering

abstract:
  We derive helicity amplitudes for diffractive leptoproduction of the S and D
wave states of vector mesons. We predict a dramatically different spin
dependence for production of the S and D wave vector mesons. We find very small
$R=\sigma_{L}/\sigma_{T}$ and abnormally large higher twist effects in
production of longitudinally polarized D-wave vector mesons.


title:
Scaling properties of transverse flow in Bjorken's scenario for heavy
  ion collisions

abstract:
  We report a simple analytic solution for the velocity $u$ of the transverse
flow of QGP at a hadronization front in Bjorken's scenario. We establish
scaling properties of the transverse flow as a function of the expansion time.
We present simple scaling formula for the expansion velocity distribution.


title: Extending the Standard Model to Include CPT- and Lorentz-Breaking Terms

abstract:
  Low-energy remnant fundamental symmetry violations may be present in nature
at levels attainable in upcoming experiments. These effects may arise through
spontaneous symmetry breaking in a more complete Lorentz covariant theory
underlying the standard model. In this work the issue of parameterizing such
violations in a consistent and complete manner is addressed. The approach is to
use the mechanism of spontaneous symmetry breaking to generate all possible
terms consistent with gauge invariance and power-counting renormalizability to
construct an extension of the standard model that includes Lorentz- and
CPT-breaking terms. A consistent quantization of the theory is developed,
conventional quantum field theoretic techniques are shown to apply, and some
ramifications for quantum electrodynamics are explored.


title:
Use of singular classical solutions for calculation of multiparticle
  cross sections in field theory

abstract:
  A method of reducing the problem of the calculation of tree multiparticle
cross sections in $\phi^4$ theory to the solution of a singular classical
Euclidean boundary value problem is introduced. The solutions are obtained
numerically in terms of the decomposition in spherical harmonics, and the
corresponding estimates of the tree cross sections at arbitrary energies are
found. Numerical analysis agrees with analytical results obtained earlier in
the limiting cases of large and small energies.


title: Correlations for Mass-Shifted Bosons

abstract:
  We discuss a new kind of correlation, the correlation of
particle-antiparticle pairs emitted back-to-back in the local rest frame of a
medium, if medium effects cause mass modification of the quanta. The theory of
these new correlations is summarized for relativistically expanding, locally
thermalized sources.


title: Invariant Buda-Lund Particle Interferometry

abstract:
  The invariant Buda-Lund parameterization of the two-particle Bose-Einstein
correlation functions is presented, its derivation is summarized. In its
particular multi-variate Gaussian limiting case, the invariant Buda - Lund
parameterization is compared to the Bertsch-Pratt and Yano-Koonin-Podgoretskii
parameterizations, advantages and shortcomings are discussed. The invariant
Buda-Lund parameterizations are given also for non-Gaussian multi-variate
distributions, including damped oscillations in the like-particle correlation
function, that are similar to the oscillating intensity correlations of binary
stars in stellar interferometry. A separation between the pion and the proton
source is also estimated in the Buda - Lund hydro framework, the result is
utilized to extract the mean proper time of particle emission with the help of
fits to E877 data on non-identical particle correlations by Miskowiec.


title: On Neutrinos and Fermionic Mass Patterns

abstract:
  Recent data on neutrino mass differences are consistent with a hierarchical
neutrino mass structure strikingly similar to what is observed for the other
fermionic masses.


title: Nonlocality and gravity-induced CP violation

abstract:
  We consider a space-time dependent relative phase between the right- and
left-handed spinors and show that it results in a violation of locality in the
presence of gravity once the demand of parity covariance is dropped. This
violation of locality is such that it readily interprets itself as a
gravity-induced CP violation, and at the same time confirms an earlier remark
by Wigner that a representation space carries more information than a wave
equation. This happens, as Kirchbach has noted, because while the
dimensionality of an irreducible representation space does not depend upon the
concrete realization of the symmetry generators, Noether currents (Dirac,
versus Majorana, versus the CP violating construct presented here) do. The
gravity-induced CP violation provides a dynamical reason on how a neutron star
carrying its baryon and lepton numbers can collapse into a black hole and loose
information on the latter characteristics.


title: Quark Mass Hierarchies and Maximal CP--Violation

abstract:
  It is argued taking into account the observed mass spectra of the leptons and
quarks that the phenomenon of flavor mixing is intimately related to the mass
spectra. We discuss a particularly interesting way to describe the flavor
mixing which is particularly suited for models of quark mass matrices based on
flavor symmetries. CP violated is maximal or class to being maximal in our
approach.


title: J/psi+gamma production at the LHC

abstract:
  The associated production of J/psi + gamma at the LHC is studied within the
NRQCD framework. The signal we focus on is the production of a J/psi and an
isolated photon produced back-to-back, with their transverse momenta balanced.
It is shown that even for very large values of transverse momentum (pT of the
order of 50 GeV) the dominant contribution to this process is not
fragmentation. This is because of the fact that fragmentation-type
contributions to the cross-section come from only a q q(bar) initial state,
which is suppressed at the LHC. We identify gg-initiated diagrams higher-order
in alpha(s) which do have fragmentation-type vertices. We find, however, that
the contribution of these diagrams is negligibly small.


title:
QCD Corrections to Four-jet Production and Three-jet Structure in e+ e-
  annihilation

abstract:
  We report on the general purpose numerical program MERCUTIO, which can be
used to calculate any infrared safe four-jet quantity in electron-positron
annihilation at next-to-leading order. The program is based on the dipole
formalism and uses a remapping of phase-space in order to improve the
efficiency of the Monte Carlo integration. Numerical results are given for the
four-jet fraction and the D-parameter. These results are compared with already
existing ones in the literature and serve as a cross-check. The program can
also be used to investigate the internal structure of three-jet events at NLO.
We give results for previously uncalculated observables: the jet broadening
variable and the softest-jet explanarity.


title: QCD corrections to FCNC decays mediated by Z-penguins and W-boxes

abstract:
  QCD corrections are evaluated to FCNC processes like $B \to X_s \nu
\bar{\nu}$, $K \to \pi \nu \bar{\nu}$, $B \to l^+ l^-$ or $K_L \to \mu^+
\mu^-$, i.e. to processes mediated by effective operators containing neutrino
currents or axial leptonic currents. Such operators originate from $W$-box and
$Z$-penguin diagrams in the Standard Model. QCD corrections to them are given
by two-loop diagrams. We confirm results for those diagrams which are already
present in the literature. However, our analytical expressions for the Wilson
coefficients disagree, due to a subtlety in regulating spurious IR divergences.
The numerical effect of the disagreement is rather small. The size of the
perturbative QCD corrections compared to the leading terms depends on the
renormalization scheme used at the leading order. It varies from 0 to around
15% for a reasonable class of schemes. The uncertainty originating from
uncalculated higher-order (three-loop) QCD corrections is expected to be around
1% .


title:
Baryons As Hyperspherical O(4) Partial Waves -- Is This The Message From
  The Spectra?

abstract:
  It is argued that the baryon excitations group to four-dimensional partial
waves described by means of the three Rarita-Schwinger (RS) fields [(\sigma -1
)/2 ,(\sigma -1)/2]* [(1/2, 0)+(0,1/2)] with \sigma =2,4 and 6, where all
components happen to be occupied. In the O(4) decomposition of the \pi N
scattering amplitudes, the RS spin- and parity clusters appear as poles on the
complex energy plane, socalled H"ohler poles. This phenomenon indicates that
the symmetry of the \pi N scattering amplitude is O(4) and thereby the
space-time version of chiral symmetry, rather than O(3). Accordingly, the
baryon spectrum generating algebra is su(2)_I*su(3)_c*o(1,3)_{ls} rather than
su(6)_{sf} * su(3)_c * o(3)_l. The nucleon and \Delta spectra below \sim 2500
MeV are complete up to only 5 `missing' resonances. The three O(4) poles are
distributed over two distinct Fock spaces of opposite vacuum parities thus
defining the energy scale of the chiral phase transition for baryons. Within
this new symmetry scenario, the covariant description of the RS baryon clusters
is straightforward and their averaged masses are fitted by a Balmer-series like
formula emerging from a simple quark-diquark model in the O(4) basis with
Coulomb potential and a four-dimensional rigid rotator.


title: Introduction to Electroweak Symmetry Breaking

abstract:
  An introduction to the physics of electroweak symmetry breaking is given. We
discuss Higgs boson production in $e^+e^-$ and hadronic collisions and survey
search techniques at present and future accelerators. Indirect limits on the
Higgs boson mass from triviality arguments, vacuum stability, and precision
electroweak measurements are presented. An effective Lagrangian, valid when
there is no low mass Higgs boson, is used to discuss the physics of a strongly
interacting electroweak symmetry breaking sector. Finally, the Higgs bosons of
the minimal supersymmetric model are considered, along with the resulting
differences in phenomenology from the Standard Model.


title:
Small-x F_2 Structure Function of a Nucleus Including Multiple Pomeron
  Exchanges

abstract:
  We derive an equation determining the small-x evolution of the F_2 structure
function of a large nucleus which includes all multiple pomeron exchanges in
the leading logarithmic approximation using Mueller's dipole model. We show
that in the double leading logarithmic limit this evolution equation reduces to
the GLR equation.


title: Heavy Baryons - Status and Overview (Theory)

abstract:
  We review recent progress in the understanding of the physics of heavy
baryons. We begin our review by presenting some highlights of recent
experimental findings on charm and bottom baryons and briefly comment on their
theoretical implications. On the theoretical side we review new results on the
renormalization of HQET, on the Isgur-Wise function for $\Lambda_b \to
\Lambda_c$ transitions and on the flavour-conserving one-pion transitions
between heavy baryons.


title: Diffractive charged meson pair production

abstract:
  We investigate the possibility to measure the nonforward gluon distribution
function by means of diffractively produced \pi^+\pi^- and K^+K^- pairs in
polarized lepton nucleon scattering. The resulting cross sections are small and
are dominated by the gluonic contribution. We find relatively large spin
asymmetries, both for \pi^+\pi^- and for K^+K^- pairs.


title: Hadron Structures and Perturbative QCD

abstract:
  In the first part of this talk, I will summarize recent developments in the
study of the chiral-odd spin-dependent parton distributions h_1(x,Q^2) and
h_L(x,Q^2) of the nucleon, in particular, (i) Next-to- leading order Q^2
evolution of h_1(x,Q^2) and (ii) Leading order Q^2 evolution of the twist-3
distribution $h_L(x,Q^2)$ and the universal simplification of the Q^2 evolution
of all the twist-3 distributions in the large $N_c$ limit. The second part of
this talk will be devoted to a systematic analysis on the light-cone
distribution amplitudes of vector mesons ($\rho$, $\omega$, $\phi$, $K^*$ etc)
relevant for exclusive processes producing these mesons. In particular, twist-3
distribution amplitudes are discussed in detail.


title: Condensates Break Chiral Symmetry

abstract:
  In the physical vacuum of QCD, the energy density of light-quark fields
strongly coupled to slowly varying gluon fields can be negative. The states
that drive this energy density lowest are condensates of pairs of quarks and
antiquarks of nearly opposite momenta. These quark-antiquark condensates break
chiral symmetry. They may also affect other features of hadronic physics, such
as the range of the strong force and the confinement of color.


title: The Color Singlet Relativistic Correction in $J/\psi$ Photoproduction

abstract:
  The $O(v^2)$ relativistic correction for inelastic $J/\psi$ photoproduction,
in which heavy quark pairs are in the dominant Fock state of the quarkonium, is
studied in the framework of NRQCD factorization. An assessment of its
significance, particularly in comparison to the color octet contributions, is
made. It is found that the impact on the energy distribution is negative in
certain regions of phase space. The predictions are compared with
photoproduction data from DESY-HERA.


title: HERA Physics Beyond the Standard Model

abstract:
  The prospects of physics beyond the standard model in deep inelastic
scattering are reviewed, emphasizing some scenarios which attained attention
after the observation of an excess of events with large momentum transfer at
HERA.


title:
The Rare Decays $K\to\pi\nu\bar\nu$, $B\to X\nu\bar\nu$ and $B\to
  l^+l^-$ -- An Update

abstract:
  We update the Standard Model predictions for the rare decays
$K^+\to\pi^+\nu\bar\nu$ and $K_L\to\pi^0\nu\bar\nu$. In view of improved limits
on $B_s$--$\bar B_s$ mixing we derive a stringent and theoretically clean
Standard Model upper limit on $B(K^+\to\pi^+\nu\bar\nu)$, which is based on the
ratio of $B_d$--$\bar B_d$ to $B_s$--$\bar B_s$ mixing, $\Delta M_d/\Delta
M_s$, alone. This method avoids the large hadronic uncertainties present in the
usual analysis of the CKM matrix. We find $B(K^+\to\pi^+\nu\bar\nu)< 1.67\cdot
10^{-10}$, which can be further improved in the future. In addition we consider
the extraction of $|V_{td}|$ from a future measurement of
$B(K^+\to\pi^+\nu\bar\nu)$, discussing the various sources of uncertainties
involved. We also investigate theoretically clean constraints on
$B(K_L\to\pi^0\nu\bar\nu)$. We take the opportunity to review the
next-to-leading order (NLO) QCD corrections to $K\to\pi\nu\bar\nu$,
$K_L\to\mu^+\mu^-$, $B\to X\nu\bar\nu$ and $B\to l^+l^-$, including a small
additional term that had been missed in the original publications. The
phenomenological impact of this change is negligible, the corresponding
numerical shift being essentially within the small perturbative uncertainties
at the NLO level.


title: Bound on the tau neutrino magnetic moment from the Super-Kamiokande data

abstract:
  It is shown that recent results from the Super-Kamiokande detector constrain
the tau neutrino diagonal magnetic moment to $\mu_{\nu_{\tau}} < 1.3\times
10^{-7} \mu_{B}$ for the case of $\nu_{\mu}\to \nu_{\tau}$ interpretation of
the atmospheric neutrino anomaly. It is pointed out that the large magnetic
moment of the tau neutrino could affect further understanding of the origin of
the anomaly.


title: Moduli and Monopoles

abstract:
  Long periods of coherent oscillations of moduli fields relax the bound on
possible initial monopole density in the early universe, and in some cases
eliminate it completely.


title: Differential Renormalization and Dimensional Reduction

abstract:
  We describe the equivalence at one loop between constrained differential
renormalization and regularization by dimensional reduction in the MS scheme.
To illustrate it, we reexamine the calculation of supergravity corrections to
(g-2)_l.


title: Recent Developments in Physics Far Beyond the Standard Model

abstract:
  String theory is the leading candidate for a unified theory of the standard
model and gravity. In the last few years theorists have realized that there is
a unique structure underlying string theory. In this unification a prominent
role is played by the duality symmetries which relate different theories. I
present a brief overview of these developements and discuss their possible
impact in low-energy physics. One of the lessons learned is that the string
scale, usually asumed to be of order of the Planck scale, could be arbitrarily
low, even close to accelerator energies.


title: Is there a light fermiophobic Higgs ?

abstract:
  The most general Two Higgs Doublet Model potential without explicit CP
violation depends on 10 real independent parameters. There are two different
ways of restricting this potential to 7 independent parameters. This gives rise
to two different potentials, $V_{(A)}$ and $V_{(B)}$. The phenomenology of the
two models is different, because some trilinear and quartic Higgs couplings are
different. As an illustration, we calculate the decay width of $h^0 \to \gamma
\gamma$, where precisely due to the different trilinear couplings the loop of
the charged Higgs gives different contributions. We also discuss the
possibility for the existence of a light fermiophobic Higgs.


title: New experimental tests of sum rules for charmed baryon masses

abstract:
  New experimental measurements are used to test model independent sum rules
for charmed baryon masses. Sum rules for medium-strong mass differences are
found to be reasonably well satisfied with increasing accuracy, and the new
measurements permit an improved prediction of $2778\pm 9$ MeV for the mass of
the $\Omega_c^{*0}$. But an isospin breaking sum rule for the $\Sigma_c$ mass
splittings is still in significant disagreement posing a serious problem for
the quark model of charmed baryons. Individual $\Sigma_c$ mass splittings are
investigated, using the new CLEO measurement of the $\Xi_c^\prime$ mass
splitting, but the accuracy is not yet sufficient for a good test.