title: Scale Invariant $O(g^4)$ Lipatov Kernels at Non-Zero Momentum Transfer

abstract:
  We summarize recent work on the evaluation of the scale invariant
next-to-leading order Lipatov kernel, constructed via transverse momentum
diagrams. At zero momentum transfer the square of the leading-order kernel
appears together with an additional component, now identified as a new
partial-wave amplitude, having a separate, holomorphically factorizable,
spectrum. We present a simplified expression for the full kernel at non-zero
momentum transfer and give a complete analysis of its infrared properties. We
also construct a non-forward extension of the new amplitude which is infra-red
finite and satifies Ward identity constraints. We conjecture that this new
kernel has the conformal invariance properties corresponding to the holomorphic
factorization of the forward spectrum.


title: Higher-Order Corrections to BFKL Evolution from $t$-Channel Unitarity

abstract:
  Using reggeon diagrams as a partial implementation of $t$-channel unitarity,
$O(g^4)$ corrections to the BFKL evolution equation have been obtained. We
describe the spectrum and holomorphic factorization properties of the resulting
scale-invariant kernel. For a gauge theory, $t$-channel unitarity can be
studied directly in the complex $j$-plane by implementing Ward identity
constraints together with the group structure of reggeon interactions. We
discuss how both the $O(g^2)$ BFKL kernel and the $O(g^4)$ corrections can then
be derived.


title: Axial Anomaly and the Nucleon Spin

abstract:
  In this letter, we have taken a particular Lagrangian, which was introduced
to resolve U(1) problem, as an effective QCD Lagrangian, and have derived a
formula of the quark content of the nucleon spin. The difference between quark
content of the proton (\Delta\Sigma_p) and that of the neutron (\Delta\Sigma_n)
is evaluated by this formula. Neglecting the higher-order isospin corrections,
this formula can reduce to Efremov's results in the large N_c limit.


title: Inclusive Photoproduction of Polarized $^3P_1$ Quarkonium

abstract:
  We analyse inclusive photoproduction of polarized $^3P_1$ quarkonium in the
framework of QCD. To separate nonperturbative and perturbative parts in the
density matrix of the produced quarkonium we use a method , which is equivalent
to the diagramatic expansion widely used in analysing deeply inelastic
scatterings. A systematic expansion in a small velocity $v$, with which a heavy
quark moves inside the quarkonium in its rest frame, is performed for the
nonperturbative parts, and they are expressed as matrix elements in
nonrelativistic QCD. At the leading order of $v$ there are four matrix elements
representing nonperturbative physics. The perturbative parts are calculated at
the leading order of coupling constants. Some numerical results, especially,
numerical results for HERA are given.


title: Extended technicolor contribution to the Zbb vertex

abstract:
  The deviation of the experimental value of $R_b \equiv \Gamma_b/\Gamma_h$
from the standard-model prediction can be naturally explained in the extended
technicolor scenario.The diagonal extended technicolor gauge boson which
flavor-diagonally couples with both the ordinary fermions and the
techni-fermions plays an important role in order to have the appropriate
radiative correction to the $Zbb$ vertex. But since the diagonal extended
technicolor gauge boson gives too large positive contribution to the $T$
parameter, we need some new mechanisms which generate negative contribution to
the $T$ parameter.


title:
Enhancement of the Transition Magnetic Moments of a Neutrino by
  Degenerate Electrons

abstract:
  The one-loop induced magnetic dipole moments of a neutrino are examined in a
background of degenerate electrons in the standard model. For the
nonrelativistic neutrino, they are enhanced by a factor \( (8\pF/3\mnu) \),
where \pF\ is the electron Fermi momentum and \mnu\ the neutrino mass. For the
relativistic neutrino, they enhance the flavor-changing but helicity-conserving
process because of the absence of the GIM cancellation.


title: Theoretical aspects of singly polarized hadron-hadron collisions

abstract:
  The special role played by singly polarized high-energy hadron-hadron
collisions in Spin Physics is discussed: In such processes, the measured and
the calculated quantities can be and have been directly compared with each
other --- without data-extrapolation and without sum rules. It is in this kind
of processes, where significant asymmetries (up to 30-40\%) have been observed.
It is also in this kind of processes, where the obtained data and the
predictions of the conventional theories dramatically disagree with each other.
Attempts to understand the existing data are briefly summarized. Predictions
for further experiments are presented.


title: $\Upsilon(4S)\to B^0 \bar{B^0} \gamma$ Background at B-Factories

abstract:
  We give an estimate of the $C$-even $B^0 \bar{B^0}$ background coming from
the radiative decay $\Upsilon(4S)\to B^0\bar B^0\gamma$ at $B$-factories. Our
result $B(\Upsilon(4S)\to B^0\bar B^0\gamma) \simeq 3 \times 10^{-9}$ shows
that such background could be safely neglected in the analyses of $CP$
violating effects.


title:
On the tensor formulation of effective vector Lagrangians and duality
  transformations

abstract:
  Using two different methods inspired by duality transformations we present
the equivalence between effective Lagrangians for massive vector mesons using a
vector field and an antisymmetric tensor field. This completes the list of
explicit field transformations between the various effective Lagrangian methods
to describe massive vector and axial vector mesons.


title: A Status Report on Chiral Dynamics: Theory and Experiment

abstract:
  This paper gives an overview of a Workshop on Chiral Dynamics: Theory and
Experiment which was held at MIT July 25-29, 1994; its unique feature was the
equal mixture of theory and experiment. The purpose of the workshop was to
bring together many of the active participants to assess the status of the
field and to explore fruitful future directions. The foundations and present
status of the theory were reviewed as well as the experimental status of the
field. To facilitate the discussion of future directions working groups were
organized on Threshold Photo/Electropion Production, Two-Pion Threshold and the
Chiral Anomaly, Nucleon Polarizabilities, Pion and Sigma Polarizabilities,
$\pi-\pi$ Interactions, and $\pi$-N Interactions; these subjects were the focus
of the experimental aspects of the workshop.


title: Neutrino masses in supersymmetric theories

abstract:
  Extensions of the Standard Model with additional U(1) symmetries can describe
the hierarchy of fermion masses and mixing angles, including neutrinos. The
neutrino masses and mixings are determined up to a discrete ambiguity
corresponding to the representation content of the Higgs sector responsible for
the Majorana mass matrix. The solar and the atmospheric neutrino deficits as
well as the COBE data, may be explained simultaneously in specific schemes
motivated by symmetries. Using simple, analytic expressions, it is possible to
demonstrate the known effect that for small $\tan\beta$, phenomenologically
interesting neutrino masses would disturb the bottom-tau unification. This
however can be avoided in schemes with a large $\mu-\tau$ mixing in the charged
leptonic sector. On the other hand, for the large $\tan\beta$ regime, due to
the fixed point properties of the top as well as the bottom coupling (which are
described by analytic expressions, for sufficiently large couplings) no
modification to the bottom-tau unification would occur. Still, large mixing in
the $\mu$-$\tau$ sector is desirable in this case as well, in order to have a
solution to the atmospheric neutrino problem. In the same schemes, a relatively
heavy strange quark $\approx 200$ MeV is also predicted.


title: Physics at LEP and Yukawa Coupling Unification

abstract:
  We discuss the impact of the recent precision measurements at LEP on the
minimal supersymmetric standard model. We show that the values of $\tan\beta$
necessary to induce large positive corrections to $R_b$ are the same as the
ones preferred by the unification of the bottom and $\tau$ Yukawa couplings in
the MSSM for the current measured value of $M_t$. We discuss the relevance of
the preferred parameter space for the Higgs and sparticle searches at LEP2.
Remarkably, it follows that the LEP measurements can provide information about
the structure of soft supersymmetry breaking parameters at $M_{GUT}$. Finally,
we briefly discuss the properties of a supersymmetric model with four
generations, for which the fit to $R_b$ naturally improves with respect to the
one in the Standard Model.


title:
Generating a Fermion Mass Hierarchy in a Composite Supersymmetric
  Standard Model

abstract:
  A mechanism is suggested by which the dynamics of confinement could be
responsible for the fermion mass matrix. In this approach the large top quark
Yukawa coupling is generated naturally during confinement, while those of the
other quarks and leptons stem from non-renormalizable couplings at the Planck
scale and are suppressed. Below the confinement scale(s) the effective theory
is minimal supersymmetric $SU(5)$ or the supersymmetric standard model.
Particles in the $\bar 5$ representations of $SU(5)$ are fundamental while
those in the $10$ and $5$ are composite. The standard model gauge group is
weakly coupled and predictions of unification can be preserved. A hierarchy in
confinement scales helps generate a hierarchical spectrum of quark and lepton
masses and ensures the Kobayashi-Maskawa matrix is nearly diagonal. However,
the most natural outcome is that the strange quark is heavier than the charm
quark; additional structure is required to evade this conclusion. No attempt
has been made to address the issues of $SU(5)$ breaking, SUSY breaking,
doublet/triplet splitting or the $\mu$ parameter. While the models presented
here are neither elegant nor complete, they are remarkable in that they can be
analyzed without uncontrollable dynamical assumptions.


title: The Status of Renormalon

abstract:
  It is shown that the series of renormalon--type graphs, which consist in the
chain of insertions to one soft(hard) gluon(photon) line is in fact ill
defined. Each new type of insertions, which appears in the higher orders of
perturbation theory, generates the correction to renormalon of the order of
$\sim 1$. However, this series of the corrections to the asymptotics although
have no small parameter but hopefully is not the asymptotic one. The
consideration based on the use of the renormalization group equation for
effective charge is supported by the direct diagrammatic picture.


title: Chiral Perturbation Theory: a Primer

abstract:
  Recently methods have been developed which exploit the chiral symmetry of QCD
in order to make rigorous contact with low energy particle physics
phenomenology. In these lectures we present a pedagogical introduction to these
techniques.


title:
Summary of the Theory Part of the International Conference on Elastic
  and Diffractive Scattering

abstract:
  The theory part of the conference is summarized with certain emphasis on the
results concerning the pomeron in soft and hard processes.


title: The Pion Structure Function in a Constituent Model

abstract:
  Using the recent relatively precise experimental results on the pion
structure function, obtained from Drell--Yan processes, we quantitatively test
an old model where the structure function of any hadron is determined by that
of its constituent quarks. In this model the pion structure function can be
predicted from the known nucleon structure function. We find that the data
support the model, at least as a good first approximation.


title:
HIGLU: A Program for the Calculation of the Total Higgs Production Cross
  Section at Hadron Colliders via Gluon Fusion including QCD Corrections

abstract:
  A program for the calculation of the total Higgs production cross section via
gluon fusion at hadron colliders including next--to--leading order QCD
corrections is presented. It is suitable especially for Standard Model Higgs
bosons and the neutral Higgs particles of the minimal supersymmetric extension.
The program provides a model--independent calculation for scalar [\CP--even] as
well as pseudoscalar [\CP--odd] Higgs bosons including the contributions of
virtual top and bottom quarks inside the loop coupled to the Higgs particles.
The relevant input parameters can be chosen from an input file. As a special
case the minimal supersymmetric extension of the Standard Model can be
investigated. The corresponding couplings are implemented including the leading
higher order corrections.


title:
A Cutoff Constrained by the Oblique Parameters in Electroweak Theory
  with Two Massless Higgs Doublets

abstract:
  Electroweak theory with two massless Higgs doublets is studied by solving
renormalization group equations for coupling constants in one-loop
approximation. A cutoff~$\Lambda$, at which one of quartic couplings in the
Higgs potential blows up, is obtained by imposing constraints from the oblique
parameter $T$ on the quartic couplings at low energy. We find $\Lambda \simeq
0.52\sim 8.4$~TeV at the Higgs mass $M_H=100$ GeV. The cutoff $\Lambda$ is at
most about $60$ TeV even if we take into account the LEP lower bound of
$M_H\simeq 64$ GeV. It cannot reach the Planck or GUT scale due to severe
experimental constraints. It is impossible in the model to realize a large
gauge hierarchy as suggested many years ago by S. Weinberg.


title: Extended Gauge Models and $e^-e^- \to W^-W^-$ at the NLC

abstract:
  We briefly discuss two possible manifestations of the lepton number violating
reaction $e^-e^- \to W_i^-W_j^{(*)-}$, which probes the masses and mixings of
heavy Majorana neutrinos, at the Next Linear Collider(NLC). Cross sections for
this process are shown to be potentially quite large at center of mass energies
of order 1-1.5 TeV. (Talk presented at the Santa Cruz Workshop on $e^-e^-$
Physics at the NLC, University of California, Santa Cruz, September 4-5, 1995.)


title:
Probing Lepton-Number Violating Couplings of Doubly Charged Higgs Bosons
  at an $e^-e^-$ Collider

abstract:
  The doubly charged Higgs bosons $\Delta^{--}$ that are present in exotic
Higgs representations can have lepton-number-violating couplings to $e^-e^-$.
We discuss general constraints and phenomenology for the $\Delta^{--}$ and
demonstrate that extremely small values for the $e^-e^-\rightarrow\Delta^{--}$
coupling (some 8 orders of magnitude smaller than the current limit) would
produce observable signals for $\Delta^{--}$ production in direct $s$-channel
production at an $e^-e^-$ collider.


title: The Analysis of Multijet Events Produced at High Energy Hadron Colliders

abstract:
  We define and discuss a set of (4N - 4) parameters that can be used to
analyse events in which N jets have been produced in high energy hadron-hadron
collisions. These multijet variables are the multijet mass and (4N - 5)
independent dimensionless parameters. To illustrate the use of the variables
QCD predictions are presented for events with up to five jets produced at the
Fermilab Tevatron Proton-Antiproton Collider. These QCD predictions are
compared with the predictions of a model in which multijet events uniformly
populate the N-body phase-space.


title:
Generating the texture of symmetric fermion mass matrices and anomalous
  hierarchy patterns for the neutrinos from an extra abelian symmetry

abstract:
  Assuming that a horizontal abelian (gauge) symmetry is at the origin of
texture zeros in the fermion mass matrices we show how realistic mass patterns
can be generated stepwise with a small number of effective operators from GUT's
and string theory. It is interesting to note that, in the minimal scenario, if
the up quark and the down quark mass matrices are generated simultaneously
their texture is formaquivalent and contains only two zeros. Textures with more
zeros (and thus more predictability) emerge if the up and down sectors are
generated stepwise. This last possibility leads to rather anomalous neutrino
patterns with mass degenerate neutrinos and large $\nu_{\mu} - \nu_{\tau}$ or
$\nu_e - \nu_{\tau}$ mixing even in the absence of hierarchy in $M_R$, the mass
matrix of the righthanded neutrinos, and as required by the LSND results if
they were to be confirmed by future experiments. In contrast if the quark mass
matrices have two zero entries (or less) the neutrino mass-mixing spectrum is
independent of the texture structure of $M_R$ -if the latter does not contain
any hierarchy of scales- and obeys the quadratic seesaw.


title: T-violation in $K_{\mu3}$ decay in a general two-Higgs doublet model

abstract:
  We calculate the transverse muon polarization in the $K^+_{\mu3}$ process
arising from the Yukawa couplings of charged Higgs boson in a general two-Higgs
doublet model where spontaneous violation of CP is present


title: QCD Analysis of the H dibaryon

abstract:
  The status of theoretical studies of the $H$ dibaryon is reviewed. Some
recent developments including the effect of the instanton induced interaction
and the QCD sum rule results are discussed in detail.


title: New $I=J$ Rules for the Baryon Vertices in $1/N_c$ Expansion

abstract:
  We apply the $1/N_c$ expansion in QCD to the baryon vertices. We find new
model independent properties for the isoscalar and isovector baryon vertices
from the view point of $1/N_c$ expansion in QCD. One of these results, $I=J$
rule, have been already found. The other properties, new $I=J$ rules, are the
rules about the isospin and strangeness dependence for the baryon vertices.


title: How to Search for Pentaquarks in High Energy Hadronic Interactions

abstract:
  The strange-anticharmed Pentaquark is a $uud\bar{c}s$ or $udd\bar{c}s$
five-quark baryon that is expected to be either a narrow resonance, or possibly
even stable against strong and electromagnetic decay. We describe this hyperon
here, its structure, binding energy and lifetime, resonance width, production
mechanisms, production cross sections, and decay modes. We describe techniques
to reduce backgrounds in search experiments and to optimize the conditions for
Pentaquark observation. Possibilities for enhancing the signal over background
in Pentaquark searches are investigated by examining predictions for detailed
momentum and angular distributions in multiparticle final states. General
model-independent predictions are presented as well as those from two models: a
loosely bound $D_{s}^-N$ molecule and a strongly-bound five-quark system.
Fermilab E791 data, currently being analyzed, may have marginal statistics for
showing definitive signals. Future experiments in the spirit of the recent
CHARM2000 workshop, such as FNAL E781 and CERN CHEOPS with $10^6-10^7$
reconstructed charmed baryon events, should have sensitivity to determine
whether or not the Pentaquark exists.


title: Constituent string model for hybrid mesonic excitations

abstract:
  The model for hybrid excitations of the QCD string with quarks is presented
starting from the perturbation theory in the nonperturbative background. The
propagation of a system containing $q \bar q$-pair and gluon is considered. The
simplified version of the Hamiltonian, including both long-range
nonperturbative interaction and Coulomb force, is derived. The masses of the
lowest $q \bar q g$ hybrids are evaluated, and numerical results for the
spectra are listed.


title: Hybrids with heavy quarks: from potential to string

abstract:
  We consider hybrid states with heavy quarks in the frame of recently proposed
constituent gluon model. Limiting regimes for model Hamiltonian are discussed.
It is shown that these regimes match smoothly, hence predictions of the model
are definite enough. We predict lowest $c \bar c g$ hybrids at $4.1 \pm 0.1$
GeV and $b \bar b g$ hybrids at $10.5 \pm 0.1$ GeV. Regge-trajectories for
hybrids are derived from the formalism. Experimental aspects of our predictions
are discussed.


title: Like Sign Top Quark Pair Production at Linear Colliders

abstract:
  In the general two Higgs doublet model with flavor changing neutral Higgs
couplings, neutral Higgs bosons may decay dominantly via $t\bar c$ or $\bar tc$
final states. At the linear collider, $e^+e^- \to h^0A^0$ or $H^0A^0$
production processes may result in $b\bar bt\bar c$, $W^+W^-t\bar c$ or $tt\bar
c\bar c$ (or $\bar t\bar tcc$) final states. The process $\gamma\gamma \to
h^0,\ A^0 \to t\bar c$ is also promising, but $e^+e^- \to (h^0,\ H^0) Z^0 \to
t\bar c Z^0$ is relatively suppressed. The possibility of observing like sign
lepton pairs, usually the hallmark for neutral meson mixing, is quite
interesting since $T^0$ mesons do not even form.


title:
Comments to the $S$-matrix interpretation of finite-temperature field
  theories

abstract:
  It is shown that there is the possibility to find at least in the
perturbation framework the Matsubara theory from the $S-$matrix interpretation
of the real-time finite-temperature theory if the system under consideration is
in an equilibrium state.


title: About the construction of p-adic QFT limit of TGD

abstract:
  The p-adic description of Higgs mechanism provides excellent predictions for
elementary particle and hadron masses. In this work the construction of p-adic
field theory limit of Quantum TGD is considered. Topological condensate defined
as a manifold obtained by gluing together p-adic spacetime regions with
different values of $p$ is identified as 'quantum average' space time defined
as absolute minimum of effective action $S_e$ associated with K\"ahler Dirac
action defining configuration space geometry. p-Adic spacetime topology is
ultrametric in accordance with the analogy with spin glass phase implied by the
vacuum degenerary of K\"ahler action. Symmetry arguments suggest that $S_e$ in
presence of fermion fields is just the super symmetrized K\"ahler Dirac action.
Super symmetrization motivated by $N=1$ super symmetry generated by right
handed neutrino replaces H-coordinates with their super counterparts and
requires color singletness of physical states appears as consistency condition.
p-Adic $Diff(M^4)$ and canonical transformations of $CP_2$ localized with
respect to $M^4$ are approximate symmetries of the effective action and broken
only by the nonflatness of the induced metric. Super gauge invariances in
interior allow only massless many boson states with vanishing electroweak and
color quantum numbers including graviton in accordance with the hypothesis that
elementary particle quantum numbers reside on boundaries. Boundary components
are idealized with world lines and Kac Moody Dirac spinors used in mass
calculations describe the conformal degrees of freedom of the boundary
component. Perturbation theory in powers of $p$ converges extremely rapidly: UV
divergences are absent but natural infrared cutoff is present.


title: Spin Structure Functions of the Nucleon

abstract:
  I begin with a general discussion about importance of constructing a picture
of the nucleon in terms of QCD degrees of freedom, emphasizing the role of spin
structure functions. I then give a short overview on the theoretical and
experimental status of the spin structure of the nucleon. Following that, I
mention several upcoming experiments to measure the flavor and sea structure in
polarized quark distributions and the polarized gluon distribution $\Delta
g(x)$. Finally, I discuss other spin-related physics, such as the
polarizabilities of gluon fields $\chi_B $ and $\chi_E$, the quark transversity
distribution $h_1(x)$, and the spin structure functions $G_1$ and $G_2$ at low
$Q^2$.


title:
Determining the CKM Unitarity Triangle From $B$ Decays to Charged Pions
  and Kaons

abstract:
  Decay rates of $B^0(t)\to\pi^+\pi^-,~B^0\to\pi^- K^+,~B^+\to\pi^+ K^0~
(K_S\to\pi^+\pi^-$) and of charge-conjugate processes are studied within flavor
SU(3) symmetry and first-order SU(3) breaking. We show that these measurements
can determine with a reasonable accuracy the two angles, $\alpha$ and $\gamma$,
of the Cabibbo-Kobayashi-Maskawa unitarity triangle.


title: Some Speculations on the Ultimate Planck Energy

abstract:
  The inability to achieve in the present universe, via electromagnetic or
gravitational acceleration, Planck energies for elementary particles is
suggested on the basis of several, some relatively sophisticated, failed
attempts. This failure is essential for schemes were the superplanckian regime
for the energies of elementary particles is ``Unphysical''. The basic
observation is that this failure to achieve superplanckian energies naturally
occurs in our universe of finite age and horizon. It does tie up in a
mysterious fashion these cosmological quantities and elementary physics
parameters such as the masses of the lightest charged fermions.


title: Testing CPT with the Neutral-D System

abstract:
  We investigate the issue of testing CPT invariance in the neutral-$D$ system,
using $D$ events obtained either from fixed-target experiments or from a
tau-charm factory. For both types of experiments we show that the expected
suppression of mixing in the $D$ system, normally viewed as a disadvantage for
CP tests, allows unsuppressed measurement of certain parameters describing CPT
violation. Asymmetries are presented that permit the extraction of parameters
for direct CPT violation in the $D$ system and for indirect CPT violation in
the $K$ system. We also show that experiments on the neutral-$D$ system provide
an alternative means for measuring conventional indirect $T$ violation in the
kaon system.


title:
Lessons from $QCD_2 (N\to\infty)$: Vacuum structure, Asymptotic Series,
  Instantons and all that

abstract:
  We discuss two dimensional $QCD (N_c\to\infty)$ with fermions in the
fundamental as well as adjoint representation. We find factorial growth $\sim
(g^2N_c\pi)^{2k}\frac{(2k)!(-1)^{k-1}}{(2 \pi)^{2k}}$ in the coefficients of
the large order perturbative expansion. We argue that this behavior is related
to classical solutions of the theory, instantons, thus it has nonperturbative
origin. Phenomenologically such a growth is related to highly excited states in
the spectrum. We also analyze the heavy-light quark system $Q\bar{q}$ within
operator product expansion (which it turns out to be an asymptotic series).
Some vacuum condensates $\la\bar{q}(x_{\mu}D_{\mu})^{2n}q\ra\sim (x^2)^n\cdot
n!$ which are responsible for this factorial growth are also discussed. We
formulate some general puzzles which are not specific for 2D physics, but are
inevitable features of any asymptotic expansion. We resolve these apparent
puzzles within $QCD_2$ and we speculate that analogous puzzles might occur in
real 4-dimensional QCD as well.


title: On The Vacuum Oscillation Solution of The Solar Neutrino Problem

abstract:
  We study the stability of the two--neutrino vacuum oscillation solution of
the solar neutrino problem with respect to changes of the total fluxes of boron
and beryllium neutrinos. For any value of $\Phi_{{\rm Be}}$ from the interval
$0.7\Phi^{{\rm BP}}_{{\rm Be}}\leq \Phi_{{\rm Be}} \leq 1.3\Phi^{{\rm
BP}}_{{\rm Be}}$ the solar $\nu_e$ oscillations into an active neutrino provide
at 95\% C.L. a description of the existing solar neutrino data for $\Phi_{{\rm
B}} \cong (0.35 - 3.4) \Phi^{{\rm BP}}_{{\rm B}}$, $\Phi^{{\rm BP}}_{{\rm B}}$
and $\Phi^{{\rm BP}}_{{\rm Be}}$ being the fluxes in the solar model of
Bahcall--Pinsonneault from 1992. For $\Phi_{{\rm Be}}\cong (0.7 -
1.3)\Phi^{{\rm BP}}_{{\rm Be}}$ we find also at 95\% C.L. two new (one new)
oscillation solutions for oscillations into active (sterile) neutrinos. The
physical implications of the new solutions for the future solar neutrino
experiments are discussed. The data rule out at 97\% -- 98\% (99 \%) C.L. the
possibility of a universal (neutrino energy independent) suppression of the
different components of the solar neutrino flux, resulting from solar $\nu_e$
oscillations or transitions into active (sterile) neutrino.


title: Non-decoupling Effects of Heavy Particles in Triple Gauge Boson Vertices

abstract:
  Non-decoupling effects of heavy particles present in beyond-the-standard
models are studied for the triple gauge boson vertices $\gamma W^+W^-$ and
$Z^0W^+W^-$. We show from a general argument that the non-decoupling effects
are described by four independent parameters, in comparison with the three
parameters $S$, $T$ and $U$ in the oblique corrections. These four parameters
of the effective triple gauge boson vertices are computed in two
beyond-the-standard models. We also study the relation of the four parameters
to the $S$, $T$, $U$ parameters, relying on an operator analysis.


title: Successful Supersymmetric Inflation

abstract:
  The temperature fluctuations in the cosmic microwave background observed by
COBE provide strong support for an inflationary phase in the early universe,
below the GUT scale. We argue that a singlet field in a hidden sector of an
effective supergravity theory yields the required inflationary potential
without fine tuning. Reheating occurs to a temperature low enough to avoid the
gravitino problem, but high enough to allow subsequent baryogenesis. Two
observational consequences are that gravitational waves contribute negligibly
to the microwave background anisotropy, and the spectrum of scalar density
perturbations is `tilted', improving the fit to large-scale structure in an
universe dominated by cold dark matter.


title:
Flat directions in the scalar potential of the supersymmetric standard
  model

abstract:
  The scalar potential of the Minimal Supersymmetric Standard Model (MSSM) is
nearly flat along many directions in field space. We provide a catalog of the
flat directions of the renormalizable and supersymmetry-preserving part of the
scalar potential of the MSSM, using the correspondence between flat directions
and gauge-invariant polynomials of chiral superfields. We then study how these
flat directions are lifted by non-renormalizable terms in the superpotential,
with special attention given to the subtleties associated with the family index
structure. Several flat directions are lifted only by supersymmetry-breaking
effects and by supersymmetric terms in the scalar potential of surprisingly
high dimensionality.


title: Hybrid states

abstract:
  Theoretical arguments are given in favour of existence of gluonic degrees of
freedom at the constituent level. Models for hybrid mesons are discussed, and
the predictions are compared with the data on meson spectroscopy in the light
quark sector. It is demonstrated that the $q\bar q g$ content might be
responsible for the properties of some recently found mesonic states.


title:
Implications of the reported deviations from the standard model for
  Z->bb and alpha_s

abstract:
  If the reported excess (over the standard model prediction) for Z->bb from
LEP persists, and is explained by supersymmetric particles in loops, then we
show that (1) a superpartner (chargino and/or stop) will be detected at LEP2,
and probably at LEP1.5 in 1995, (2) the basic parameter tan(beta) is at its
lower perturbative limit, (3) BR(t->t1+chi0) is at or above 0.4, (4) the upper
limit on m_h is considerably reduced, and (5) several important consequences
arise for the form of a unified supersymmetric theory. Our analysis is done in
terms of a general weak scale Lagrangian and does not depend on assumptions
about SUSY breaking.


title: On Testing Unitarity of the Quark Mixing Matrix

abstract:
  Unitarity triangles and characteristic measurables of the $3\times 3$
Cabibbo-Kobayashi-Maskawa (CKM) matrix are discussed. Beyond the $3\times 3$
CKM scheme we make a rephasing-invariant generalization of the
Gronau-Wyler-Dunietz approach to determine the weak phase shift in
$B^{\pm}_u\rightarrow D K^{\pm}$ or $B^0_d\rightarrow D K^{*0}$ vs
$\bar{B}^0_d\rightarrow D \bar{K}^{*0}$, which is only sensitive to the
underlying new physics in $D^0-\bar{D}^0$ mixing. We also show that the weak
angle $\gamma\equiv \arg (-V^*_{ub}V^*_{cd}V_{ud}V_{cb})$ is possible to be
determined from the $CP$ asymmetries of some $B_d$ decays, even in a
non-standard model with an extended quark sector. Brief comments are given on
tests of unitarity of the $3\times 3$ CKM matrix.


title: The Anomalous Decay eta -> pi pi gamma gamma

abstract:
  We investigate the rare radiative eta decay modes eta -> pi+ pi- gamma gamma
and eta -> pi0 pi0 gamma gamma within the framework of chiral lagrangians at
o(p^4) and present photon spectra for both processes.


title:
In a hot, chirally symmetric phase, $\pi^0$ doesn't go into $2 \gamma$,
  but $\pi^0 \sigma$ does

abstract:
  In a constituent quark model at nonzero temperature, the amplitude for $\pi^0
\rightarrow 2 \gamma$ vanishes in a chirally symmetric phase, while that for
$\pi^0 \sigma \rightarrow 2 \gamma$ does not.


title: GIM Violation and New Dynamics of the Third Generation

abstract:
  In strong dynamical schemes for electroweak symmetry breaking the third
generation must be treated in a special manner, owing to the heavy top quark.
This potentially leads to new flavor physics involving the members of the third
generation in concert with the adjoining generations, with potential novel
effects in beauty and charm physics. We give a general discussion and
formulation of this kind of physics, abstracted largely from Topcolor models
which we elaborate in detail. We identify sensitive channels for such new
physics accessible to current and future experiments.


title: Lectures on Heavy Quarks in Quantum Chromodynamics

abstract:
  A pedagogical introduction to the heavy quark theory is given. It is
explained that various expansions in the inverse heavy quark mass $1/m_Q$
present a version of the Wilson operator product expansion in QCD. A systematic
approach is developed and many practically interesting problems are considered.
I show how the $1/m_Q$ expansions can be built using the background field
technique and how they work in particular applications. Interplay between
perturbative and nonperturbative aspects of the heavy quark theory is
discussed.


title:
First limit on inclusive $B \to X_s \nu \bar\nu$ decay and constraints
  on new physics

abstract:
  The inclusive $B \to X_s \nu \bar\nu$ decay rate, on which no experimental
bound exists to date, can be constrained by searching for large missing energy
events in $B$ decays. Carefully examining the experimental and theoretical
aspects of such an analysis, we argue that the published ALEPH limit on $\BR(B
\to \tau \bar\nu)$ implies, conservatively, the bound $\BR(B \to X_s \nu
\bar\nu)<3.9\times10^{-4}$, which is less than one order of magnitude above the
standard model prediction. The LEP collaborations could significantly improve
this bound by a dedicated experimental analysis. We study the constraints this
new limit imposes on various extensions of the standard model. We derive new
bounds on the couplings of third generation fermions in models with
leptoquarks, and in supersymmetric models without R-parity. We also constrain
models where new gauge bosons are coupled dominantly to the third generation,
such as TopColor models and models based on horizontal gauge symmetries. For
models which predict an enhanced effective $bsZ$ vertex, the constraint from $B
\to X_s \nu \bar\nu$ is competitive with the limits from inclusive and
exclusive $B \to X_s \ell^+ \ell^-$ decays.


title: Bubble Nucleation in phi^{4} Models at All Temperatures

abstract:
  One possible way in which phase transitions in the early universe may have
ocurred is via nucleation of bubbles of the new phase (true vacuum) in the old
phase (false vacuum). The technique most widely used to compute the probability
of bubble nucleation is based on instanton methods in the context of the
semiclassical approximation. At zero temperature in (3+1) dimensions the
nucleation rate is dominated by the O(4) symmetric instanton, a sphere of
radius $R$, while at temperatures $T >> R^{-1}$, the decay is dominated by a
``cylindrical'' (static) instanton wtih O(3) invariance. There has been
discussion in the literature as to whether the transition between these two
regimens would be first order (discontinuity in the first derivative of the
nucleation rate at the transition temperature $T_{c}$), or second order
(continuity of the first derivative, but discontinuity of the second derivative
at $T_{c}$). In this paper we obtain the finite temperature solutions
corresponding to the quantum and the thermal regimes, and compute their action
as a function of the temperature for different values of the wall thickness in
a $\varphi^{4}$ potential. Our results indicate that only for the cases of very
large wall thickness a second order transition takes place, while for all the
other cases a first order transition occurs


title:
Time evolution of the two-jet events $e^+-e^- \to hadrons$ in the
  Dynamical String Model

abstract:
  The time dependent pion emission rate and the mean life time of the pion
source in the center of mass frame of the two-jet events have been determined
for $e^+-e^- \to hadrons$ at $\sqrt{s} = 20 - 50$ GeV by the Dynamical String
Model. It was established that the time needed for the creation of the pion
source is $5$ fm/c, whereas its life time is $\tau_0 \approx 7 - 13$ fm/c for
energies $\sqrt{s} = 20 - 50$ GeV, respectively.


title: Magnetic moments of the 3/2 resonances and their quark spin structure

abstract:
  We discuss magnetic moments of the $J=3/2$ baryons based on an earlier model
for the baryon magnetic moments, allowing for flavor symmetry breaking in the
quark magnetic moments as well as a general quark spin structure. From our
earlier analysis of the nucleon-hyperon magnetic moments and the measured
values of the magnetic moments of $\Delta^{++}$ and $\Omega^{-}$ we predict the
other magnetic moments and deduce the spin structure of the resonance
particles. We find from experiment that the total spin polarization of the
decuplet baryons, $\Delta\Sigma(3/2)$, is considerably smaller than the
non-relativistic quark model value of 3, although the data is still not good
enough to give a precise determination.


title: Dynamical Interplay of Quarks and Solitonic Meson Clouds in Baryons

abstract:
  In the Nambu--Jona-Lasinio (NJL-) model baryons are considered either as
quark-diquark-composites or as soliton configurations of mesons. The
construction of a hybrid model, which possesses a dynamical interplay between
both pictures, is presented. The Bethe-Salpeter equation for diquarks and the
Faddeev equation for diquark-quark bound states in the background of a soliton
configuration is solved.


title: Phenomenology of $\varepsilon_K$ Beyond Leading Logarithms

abstract:
  I present the QCD short distance coefficient $\eta_3$ of the $\Delta S=2$
hamiltonian in the \emph{next-to-leading order} (NLO) of renormalization group
improved perturbation theory. Since now all QCD-factors $\eta_1$, $\eta_2$ and
$\eta_3$ are known with NLO accuracy, a much higher precision in the analysis
of $\varepsilon_K$ can be achieved. The CKM phase $\delta$, $|V_{td}|$ and the
mass difference $\Delta m_{B_s}$ in the
$\text{B}_s^0-\overline{\text{B}}_s^0$-system are predicted from the measured
values of $\varepsilon_K$ and $\Delta m_{B_d}$. Finally I briefly look at the
\kkmd. This work has been done in collaboration with Stefan Herrlich.


title: Two-Body Dirac Equation and Its WFO

abstract:
  A relativistic equation is proposed for the bound state of two particles,
which is in accord with the boundary condition for the propagation of the
negative-energy states and reduces to the (one-body)Dirac equation in the
infinite limit of one of the constituent mass. It also has the symmetries to
assure the existence of the anti-bound-state with the same mass. The
interaction kernel(pseudo-potential) is systematically constructed by
diagonalizing the Hamiltonian of the background field theory, by which the
retardation effects are included in the interaction. Its wave function at the
origin(WFO) behaves properly in a manner sugested by the covariant field
theory.


title: Vortex Densities and Correlations at Phase Transitions

abstract:
  We present a model for the formation of relativistic vortices (strings) at a
quench, and calculate their density and correlations. The significance of these
to early universe and condensed-matter physics is discussed.


title:
On the Observation of Bosonic Loop Corrections in Electroweak Precision
  Experiments

abstract:
  We investigate the structure of the experimentally significant electroweak
bosonic loop corrections to the leptonic weak mixing angle, the leptonic
Z-boson decay width, and the W-boson mass. It is shown that the bosonic
corrections that have a sizable effect at the present level of experimental
accuracy are directly related to the use of the Fermi constant G_F as input
parameter for analyzing the LEP observables. Indeed, if the (theoretical value
of the) leptonic width of the W boson is used as input parameter instead of the
low-energy parameter G_F determined from muon decay, fermion-loop corrections
are sufficient for compatibility between theory and experiment.


title:
Massive multi-flavor Schwinger model at finite temperature and on
  compact space

abstract:
  The multi-flavor Schwinger model on $R^1$ at finite temperature $T$ is
mathematically equivalent to the model on $S^1$ at $T=0$. The latter is reduced
to a quantum mechanical system of $N-1$ degrees of freedom. Physics sensitively
depends on the parameter $m/T$. Finite temperature behavior of the massive
Schwinger model is quite different from that of the massless Schwinger model.


title: Strange Twists in Neutral Pion Photo/Electro-Production

abstract:
  I review the interesting tale of the electric dipole amplitude in neutral
pion photoproduction and the resulting consequences. I also discuss why there
is new life related to P--wave multipoles. Electroproduction is briefly touched
upon.


title: Nucleon Form Factors from Dispersion Theory

abstract:
  I review the results of a recent dispersion--theoretical analysis of the
nucleon electromagnetic form factors and comment on the strangeness form
factors. The need for a better data basis at low, intermediate and large
momentum transfer is stressed.


title: The Reaction $\pi N \to \pi \pi N$ at Threshold

abstract:
  I summarize the results of the complete one--loop chiral perturbation theory
calculation performed recently. It is shown that it allows to accurately pin
down the isospin two, S--wave $\pi \pi$ scattering length $a_0^2$. On the other
hand, interesting resonance physics makes a precise determination of $a_0^0$
very difficult.


title: Confinement, Quark Matter Equation of State and Hybrid Stars

abstract:
  We consider here quark matter equation of state in a relativistic harmonic
confinement model at zero temperature. The same is considered to study phase
transition of neutron matter to quark matter at high densities. This, along
with a phenomenological equation of state in the neutron matter sector is used
to study hybrid stars. Using Tolman Oppenheimer Volkoff equations, stable
solutions for hybrid stars are obtained with a maximum mass of 1.98 $M_\odot$
and radii around 10 kms with a quark core of about 1 to 2 kilometers.


title: Dynamical Determination of the Fundamental Couplings

abstract:
  We demonstrate that supergravity models containing the Standard Model,
dilaton and modulus naturally lead to dynamical symmetry breaking with
excellent phenomenology. We assume primordial supersymmetry breaking in the
form of a constant contribution to the superpotential. String inspired
relations link fundamental couplings to the dilaton vev. We specialize to a
class of models inspired by the $4$-$D$ fermionic string. Non-renormalizable
terms in the superpotential naturally produce the Higgs mixing parameter $\mu$
suitable for our mechanism. We discuss extensions and limitations of our
approach.


title:
Application of the Pinch Technique to Neutral Current Amplitudes and the
  Concept of the Z Mass

abstract:
  The pinch technique (PT) is applied to neutral current amplitudes, focusing
on the mixing problem. Extending recent arguments due to Papavassiliou and
Pilaftsis, it is shown that the use of the PT self-energies does not shift the
complex-valued position of the pole through order {\cal O}($g^4$). This leads
(to the same accuracy) to a simple interpretation of $M_Z$, the mass measured
at LEP, in terms of the PT self-energies. It is pointed out that the PT
approach provides a convenient and rather elegant formalism to discuss
important neutral current amplitudes, such as those relevant to four-fermion
processes and LEP2.


title: Interactions on Nuclei

abstract:
  I review hard photon initiated processes on nuclei. The space-time
development of the DIS reaction as viewed in the target rest frame
qualitatively describes the nuclear shadowing of quark and gluon distributions,
although it may be difficult to understand the very weak $Q^2$ dependence of
the low $x$ data. The current jet hadron energy distribution at large $\nu$ is
accurately independent of the target size even at very small energy fractions
$z \simeq 0.05$. Color transparency is verified for vector meson $(J/\psi,\
\rho)$ production, but remains enigmatic in quasiexclusive proton knockout
processes. I emphasize the importance of understanding short-range correlations
in nuclei, as manifested by subthreshold production and cumulative $x>1$ DIS
processes.


title: Strings With Axionic Content and Baryogenesis

abstract:
  We describe different electroweak strings with axionic content, including
non-topological configurations calculated numerically, and show their possible
influence on baryogenesis indicating that they may constitute a mechanism
competitive to that of bubble nucleation with two Higgs-doublets.


title: Electromagnetic Corrections to the decays $\eta \to 3\pi$

abstract:
  We calculate the electromagnetic corrections to the decays $\eta \rightarrow
3\pi$ in next to leading order in the chiral expansion. We find that the
corrections are small in accordance with Sutherland's theorem and modify
neither rate nor the Dalitz plot distributions noticeably.


title: ITEP Lectures in Particle Physics

abstract:
  Introduction to the Lecture Note Volume "ITEP Lectures in Particle Physics",
including 25 years of personal reminiscences.


title: A Perturbative Expansion for Weakly Bound States

abstract:
  We describe a perturbation expansion for the energy and wave function of a
weakly bound particle in a short-range potential in one space dimension.


title: Light and Intermediate Higgs boson search at Tevatron Energies

abstract:
  We study the Higgs boson search possibility at the TEVATRON energies. The
detailed analysis of the 4-fermion final state reactions is presented. Among
the complete set of Feynman diagrams the main contribution to the final states
comes from the Higgs signal WH and ZH, from the backgrounds WZ, ZZ and gluonic
background Wbb, Zbb with subssiquent decays of W, Z bosons. It is shown that
the important contribution to the background is connected with single top quark
production subreactions qq-bar --> tb-bar or t-bar b with the top decay to Wb.
As a result of various distributions for Higgs signal and backgrounds a number
of optimum cuts has been found. The finaleffective $b\bar{b}$ -- pair mass
distribution allows to extract the signal from Higgs with mass up to about 100
GeV at 2 TeV C.M. energy and up to about 120 GeV at 4 TeV C.M. energy for the
integrated luminosity 1000 inverse pb.


title:
Quantum Field Theory Near Thresholds of Ultra-Heavy Particles:
  Top-Antitop and Beyond

abstract:
  Quantum field theory near thresholds of ultra-heavy particles is considered.
We focus especially on the top-antitop and the stop-antistop systems. The
question of the possible large corrections due to a running width of the top
quark could be solved in this work. It was shown that a previously not
considered contribution gives rise to large cancellations and leads especially
to a gauge independent result. With the help of a new zero order equation and a
Ward identity it was further possible to derive a general therorem for bound
state corrections to the width. Furthermore a systematic derivation of the
top-antitop and the stop-antistop potential to numerical order O(\alpha_s^4)
was given. In the second part of this work we consider within the numerical
Green function approach the cross sections for the production of ultraheavy
particles near threshold. The forward-backward asymmetry and the pure axial
contribution to the top-antitop total cross section as well as the
stop-antistop total cross section are calculated. A systematic method is given
to avoid unnatural cut-offs in the nonrelativistic treatment.


title: The pion at finite temperature

abstract:
  Properties of the pion are studied at finite temperature with the help of the
PCAC and the QCD sum rule. The pionic mode is treated consistently
  with the thermal pions which consist of the ground state at finite
temperature. The temperature dependence of the pion decay constant is estimated
for $m_{q}=0$. No consistent solution is found above the critical temperature
$T_{c} = \sqrt{2} f_{\pi}^{T=0} $. The QCD sum rule shows that the finite quark
  mass makes the critical temperature move up to a temperature where the dilute
pion gas approximation is no more valid. It also suggests that the pion decay
constant and the continuum threshold decrease by $\sim 15\%$ and $\sim 10\%$,
respectively, and that the pion mass slightly ($\sim 3\%$) increases at
$T=160MeV$, where the pion gas approximation seems to break down.


title: Nucleon Spin

abstract:
  We review the theory of polarized deep inelastic scattering in light of the
most recent experimental data. We discuss the nucleon spin decomposition and
the Bjorken sum rule. The latter is used for extraction of
$\alpha_s(M_Z^2)=0.116^{{+}0.004}_{{-}0.006}$ and as a test case for a new
method of analyzing divergent perturbation series in QCD.


title:
QCD Sum Rule Analysis of the Decays $B \to K \ell^+ \ell^-$ and $B \to
  K^* \ell^+ \ell^-$

abstract:
  We use QCD sum rules to calculate the hadronic matrix elements governing the
rare decays $B \to K \ell^+ \ell^-$ and $B \to K^* \ell^+ \ell^-$ induced by
the flavour changing neutral current $b \to s$ transition. We also study
relations among semileptonic and rare $B \to K^{(*)}$ decay form factors. The
analysis of the invariant mass distribution of the lepton pair in $B \to
K^{(*)} \ell^+ \ell^-$ and of the angular asymmetry in $B \to K^* \ell^+
\ell^-$ provides us with interesting tests of the Standard Model and its
extensions.


title: Exclusive Semileptonic and Rare Radiative B Decays from QCD Sum Rules

abstract:
  I give an overview of the QCD sum rule predictions for the form factors of
B-meson weak decays to light hadrons (and leptons)


title: Spin effects in high energy diffractive reactions

abstract:
  It is shown that single and double spin asymmetries in polarized diffractive
$Q \bar Q$ production depend strongly on the spin structure of the
quark-pomeron vertex. They can be studied in future spin experiments at HERA.


title: Hadronic Decays of Excited Heavy Quarkonia

abstract:
  We construct an effective Lagrangian for the hadronic decays of a heavy
excited $s$-wave-spin-one quarkonium into its ground state. We show that
reasonable fits to the measured invariant mass spectra in the $J/\psi$ and
$\Upsilon$ systems can be obtained working in the chiral limit. The mass
dependence of the various terms in the Lagrangian is discussed on the basis of
a quark model.


title: Is there a chance to find heavy neutrinos in future linear colliders?

abstract:
  We examine two processes, the neutrino production process e^+e^- ---> N\nu
and the inverse neutrinoless double-beta decay process e^-e^- --->W^-W^- as
possible places for discovering heavy neutrinos in future lepton linear
colliders. The heavy neutrino parameters are bound from existing experimental
data. We use only one important theoretical input, the lack of a Higgs triplet.
As a consequence the neutrinos must have different CP parities. In such models
the existing experimental bounds for mixing parameters still give a chance that
heavy neutrinos can be observed in future e^+e^- and e^-e^- colliders.


title: Free Energy of QCD at High Temperature

abstract:
  Effective-field-theory methods are used to separate the free energy for a
nonabelian gauge theory at high temperature $T$ into the contributions from the
momentum scales $T$, $gT$, and $g^2T$, where $g$ is the coupling constant at
the scale $2 \pi T$. The effects of the scale $T$ enter through the
coefficients in the effective lagrangian for the 3-dimensional effective theory
obtained by dimensional reduction. These coefficients can be calculated as
power series in $g^2$. The contribution to the free energy from the scale $gT$
can be calculated using perturbative methods in the effective theory. It can be
expressed as an expansion in $g$ starting at order $g^3$. The contribution from
the scale $g^2T$ must be calculated using nonperturbative methods, but
nevertheless it can be expanded in powers of $g$ beginning at order $g^6$. We
calculate the free energy explicitly to order $g^5$. We also outline the
calculations necessary to obtain the free energy to order $g^6$.


title:
Dilepton bremsstrahlung from pion-pion scattering in a relativistic OBE
  model

abstract:
  We have made a detailed and quantitative study of dilepton production via
bremsstrahlung of a virtual photon during pion-pion collisions. Most
calculations of electromagnetic radiation from strong interaction processes
rely on the soft photon approximation (SPA). The conditions underlying this
approximation are generally violated when dilepton spectra are calculated in
terms of their invariant mass, so that an approach going beyond the SPA becomes
necessary. Superseding previous derivations, we derive an exact formula for the
bremsstrahlung cross section. The resulting formulation is compared to various
forms based on the SPA, the two-particle phase space approximation and
R\"uckl's formula using a relativistic One Boson Exchange (OBE) model. Within
the OBE approach, we show that approximations to the bremsstrahlung dilepton
cross sections often differ greatly from the exact result; discrepancies become
greater both with rising temperature and with invariant mass. Integrated
dilepton production rates are overestimated by R\"uckl-based approximations by
factors 1.5--8.0. The largest discrepancies occur for the reaction $\pi^+\pi^+
\to \pi^+\pi^+\ell^+\ell^-$, where such approximations overestimate the exact
rate by factors ranging from 2 to 30 for invariant masses between 10 and 500
MeV. Our findings, combined with recent estimates of the Landau-Pomeranchuk
effect, indicate that bremsstrahlung dileptons rates in ultrarelativistic heavy
ion collisions should be even more suppressed than had been thought before.


title: On the Behaviour of Non--Singlet Structure Functions at Small $x$

abstract:
  The resummation of $O(\alpha_s^{l+1} \ln^{2l} x)$ terms in the evolution
kernels of non--singlet combinations of unpolarized and polarized structure
functions is investigated. The agreement with complete calculations up to order
$\alpha_s^2$ is demonstrated, and the leading small-$x$ contributions to the
three--loop non--singlet splitting functions $P^{\pm}$ are derived. The
additional contributions due to the resummed terms are studied numerically for
the most important non--singlet structure functions. They are found to be about
$1\,\%$ or smaller in the kinematical regions accessible at present and in the
foreseeable future.


title: On the Solution to the Polonyi Problem with No-Scale Type Supergravity

abstract:
  We study the solution to the Polonyi problem in the framework of no-scale
type supergravity. In such a model, Polonyi field can weigh as $O(10{\rm TeV})$
and decay just before the big-bang nucleosynthesis. It is shown that in spite
of a large entropy production by the decay of the Polonyi field, one can
naturally explain the present value of the baryon-to-entropy ratio, $n_B/s \sim
(10^{-10}-10^{-11})$ if the Affleck-Dine mechanism for baryogenesis works. It
is pointed out, however, that there is another cosmological problem related to
the abundance of the lightest superparticles produced by the decay of the
Polonyi field.


title: Low-Energy Supersymmetry: Prospects and Challenges

abstract:
  An introduction to the minimal supersymmetric Standard Model (MSSM) is given.
The motivation for ``low-energy'' supersymmetry is reviewed, and the structure
of the MSSM is outlined. In its most general form, the MSSM can be viewed as a
low-energy effective theory parametrized by a set of arbitrary
soft-supersymmetry-breaking parameters. A variety of techniques for reducing
the parameter freedom of the MSSM are surveyed. The search for supersymmetry
below and above the threshold for supersymmetric particle production presents a
challenging task for experimentalists at present and future colliders.


title: Excited Neutrino at Next Linear Colliders

abstract:
  The possibility of single and pair excited neutrino production in high energy
e+e-, gamma-e and gamma-gamma collisions on linear colliders is studied. The
integrated cross sections of these subproceses are calculated. Special
attention is paid to search for excited neutrino in e-gamma --> W- W+ e
process. Lower limits for the compositeness parameter estimated which will be
available on the experiments at VLEPP, SLAC, JLC and DESY future linear
colliders.


title: Vector-like Strong Coupling Theory with Small S and T Parameters

abstract:
  We discuss a mechanism which can reduce the S and T parameters in dynamical
electroweak symmetry breaking scenario. It is interesting that not only T but
also S parameters can be made small even if large isospin violation exists,
which can realize the heavy top quark. The point is that if massive vector-like
fermions, which have gauge invariant masses, can condense and break the
electroweak symmetry, the S and T parameters can be small because of the
decoupling theorem. Moreover, the model predicts a heavier Higgs boson, which
may be found in LHC. The presentation basically follows the original papers.


title: Resummation of large corrections in inclusive $B$ meson decays

abstract:
  We show that the resummation technique developed recently for heavy-light
systems and the conventional approach based on the factorization of Wilson
loops are equivalent. The two methods lead to the same results of the
resummation of large corrections in inclusive $B$ meson decays.


title: $B_s^0 \to D_s^-a_1^+$ decay channel in the $B_s^0$-mixing studies

abstract:
  The usefulness of the $B_s^0 \to D_s^-a_1^+, D_s^- \to \phi \pi^- \to
K^+K^-\pi^-, a_1^+ \to \rho^0 \pi^+ \to \pi^+ \pi^- \pi^+$ decay chain is
investigated for the $B_s$-reconstruction in the future ATLAS $B_s$-mixing
experiment. It is shown that this decay channel is almost as suitable for this
purpose as previously studied $B_s^0 \to D_s^-\pi^+$.


title:
Classical and quantum many-body description of bremsstrahlung in dense
  matter (Landau - Pomeranchuk - Migdal effect)

abstract:
  Some considerations about the importance of coherence effects for
bremsstrahlung processes in non--equilibrium dense matter (Landau - Pomeranchuk
- Migdal - effect) are presented. They are of particular relevance for the
application to photon - and di-lepton production from high energy nuclear
collisions, to gluon radiation in QCD transport, or parton kinetics and to
neutrino and axion radiation from supernova explosion and from hot neutron
stars. The soft behavior of the bremsstrahlung from a source described by
classical transport models is discussed and pocket correction formulas for the
in-matter radiation cross sections are suggested in terms of standard transport
coefficients. The radiation rates are also discussed within a non--equilibrium
quantum field theory (Schwinger - Kadanoff - Baym - Keldysh) formulation. A
classification of diagrams and corresponding resummation in physically
meaningful terms is proposed, which considers the finite damping width of all
source particles in matter. This way each diagram in this expansion is already
free from the infra--red divergences. Both, the correct quasi--particle and
quasi--classical limits are recovered from this subset of graphs. Explicit
results are given for dense matter in thermal equilibrium. The diagrammatic
description may suggest a formulation of a transport theory that includes the
propagation of off--shell particles in non--equilibrium dense matter.


title: $Q^2$ Dependence of the Bjorken Sum Rule

abstract:
  We discuss various estimates of the magnitude of higher-twist corrections to
the Bjorken sum rule in polarized deep inelastic scattering.


title: $\nu_\tau$ Oscillation Experiments and Present Data

abstract:
  Our goal in this paper is to examine the discovery potential of laboratory
experiments searching for the oscillation $\nu_\mu(\nu_e) \rightarrow
\nu_\tau$, in the light of recent data on solar and atmospheric neutrino
experiments, which we analyse together with the most restrictive results from
laboratory experiments on neutrino oscillations in a four-neutrino framework.}


title: Recombination Methods for Jets in $p\pbar$ Collisions

abstract:
  A jet algorithm must specify how to (re-)combine different partons or towers
into a single four-vector. Various recombination schemes have been used
experimentally to examine the transverse energy profile of jets in hadron
colliders. Generally, the data is insensitive to which scheme is used. However,
we argue that the recombination scheme previously used by the \DO\
collaboration is expected to have large perturbative corrections and should not
be used for the purposes of making a quantitative comparison with fixed-order
perturbation theory.


title:
Radiative Decays of Excited $\Lambda_Q$ Baryons in the Bound State
  Picture

abstract:
  It is shown that, in the bound state picture, the $\Lambda_c(2593)
\to\Lambda_c\gamma$ and $\Lambda_c(2625)\to\Lambda_c\gamma$ decays are severely
suppressed. On the other hand, for their bottom counterparts, which are
predicted to have masses 5900 and 5926 MeV respectively, may have significant
radiative branching ratio. In particular, the
$\Lambda_b(5926)\to\Lambda_b\gamma$ mode may even dominate over the strong
decay mode. The isospin allowed $\Lambda^{**}_Q\to\Sigma_Q\gamma$ mode is
expected to be small.


title: Chaotic Behavior of Particle Production in Branching Processes

abstract:
  The notion of chaotic behavior is examined for particle production in
branching processes. Two types of branching are considered: non-Abelian gauge
interaction and an Abelian cascade model. Properties of the production
processes are investigated by Monte Carlo stimulation. The ``temporal''
behavior is studied by following the fluctuations in the multiplicities of each
generation as the branching evolves. The ``spatial'' behavior is described in
terms of the fluctuations of the normalized factorial moments from event to
event. The information dimension and a new entropy index are determined. When
all the measures are taken together, they collectively give a strong suggestion
that the QCD branching process is chaotic, while the Abelian cascade model is
not.


title: An amplitude analysis of the $\overline{N}N \to \pi^- \pi^+$ reaction

abstract:
  A simple partial wave amplitude analysis of $\overline{p}p \rightarrow \pi^-
\pi^+$ has been performed for data in the range p$_{\sl lab}$ = 360 -- 1000
MeV/c. Remarkably few partial waves are required to fit the data, while the
number of required $J$ values barely changes over this energy range. However,
the resulting set of partial wave amplitudes is not unique. We discuss possible
measurements with polarized beam and target which will severely restrict and
help resolve the present analysis ambiguities. New data from the reaction
$\overline{p}p \rightarrow \pi^0 \pi^0$ alone, are insufficient for that
purpose.


title: Gluino mass from dynamical supersymmetry breaking

abstract:
  We present a new mechanism for gluino mass generation in models of dynamical
supersymmetry breaking. The mechanism requires two colored chiral superfields
which feel a nonabelian gauge interaction such that a fermion condensate is
formed at a scale of order 1 TeV. Renormalizable hidden sector models, which
typically yield unacceptably light gauginos, become viable if a gauge singlet
is coupled to these chiral superfields. Moreover, the interactions of the gauge
singlet with the Higgs superfields substitute the $\mu$-term. Visible sector
models can also incorporate this mechanism; however, the models of dynamical
supersymmetry breaking previously analyzed cannot be fitted in a simple visible
sector model because they lead to vacuum expectation values for charged
scalars.


title: Vector Meson Mixing and Charge Symmetry Violation

abstract:
  We discuss the consistency of the traditional vector meson dominance (VMD)
model for photons coupling to matter, with the vanishing of vector meson-meson
and meson-photon mixing self-energies at q^2=0. This vanishing of vector mixing
has been demonstrated in the context of rho-omega mixing for a large class of
effective theories. As a further constraint on such models, we here apply them
to a study of photon-meson mixing and VMD. As an example we compare the
predicted momentum dependence of one such model with a momentum-dependent
version of VMD discussed by Sakurai in the 1960's. We find that it produces a
result which is consistent with the traditional VMD phenomenology. We conclude
that comparison with VMD phenomenology can provide a useful constraint on such
models.


title: Duality of a Supersymmetric Model with the Pati-Salam group

abstract:
  Recently one of the authors proposed a dual theory of a Supersymmetric
Standard Model (SSM), in which it is naturally understood that at least one
quark (the top quark) should be heavy, i.e., almost the same order as the weak
scale, and the supersymmetric Higgs mass parameter $\mu$ can naturally be
expected to be small. However, the model cannot have Yukawa couplings of the
lepton sector. In this paper, we examine a dual theory of a Supersymmetric
Model with the Pati-Salam gauge group $SU(4)_{PS}\times SU(2)_L\times SU(2)_R $
with respect to the gauge group $SU(4)_{PS}$. In this scenario, Yukawa
couplings of the lepton sector can be induced. In this model the Pati-Salam
breaking scale should be around the SUSY breaking scale.


title: Massive Electrodynamics and the Magnetic Monopoles

abstract:
  We investigate in detail the problem of constructing magnetic monopole
solutions within the finite-range electrodynamics (i.e., electrodynamics with
non-zero photon mass, which is the simplest extension of the standard theory;
it is fully compatible with the experiment). We first analyze the classical
electrodynamics with the additional terms describing the photon mass and the
magnetic charge; then we look for a solution analogous to the Dirac monopole
solution. Next, we plug the found solution into the Schr\"{o}dinger equation
describing the interaction between the the magnetic charge and the electron.
After that, we try to derive the Dirac quantization condition for our case.
Since gauge invariance is lost in massive electrodynamics, we use the method of
angular momentum algebra. Under rather general assumptions we prove the theorem
that the construction of such an algebra is not possible and therefore the
quantization condition cannot be derived. This points to the conclusion that
the Dirac monopole and the finite photon mass cannot coexist within one and the
same theory. Some physical consequences of this conclusion are considered. The
case of t'Hooft-Polyakov monopole is touched upon briefly.


title:
Quark Confinement in Light-Front QCD and A Weak-Coupling Treatment to
  Heavy hadrons

abstract:
  In this paper, we develop a weak-coupling treatment of nonperturbative QCD to
heavy hadrons on the light-front. First, we present a derivation of quark
confining interaction in light-front QCD for heavy quark systems, based on the
recently developed light-front similarity renormalization group approach and
the light-front heavy quark effective theory. The resulting effective
light-front QCD Hamiltonian $H_\lambda$ at a low-energy cutoff $\lambda$
manifests the coexistence of a confining potential and a Coulomb potential. A
clear light-front picture of quark confinement emerges. Using this low energy
QCD Hamiltonian $H_\lambda$, we study heavy hadron bound state equations in the
framework of a recently proposed possible weak-coupling treatment of
non-perturbative QCD. Light-front heavy hadron bound states with definite spin
and parity are constructed and the general structure of the corresponding
wavefunctions is explored. A Gaussian-type wavefunction ansatz is used to solve
the light-front quarkonium bound state equation. We find that the effective
coupling constant determined from the quarkonium bound state equation can be
arbitrarily small so that the weak-coupling treatment to heavy hadron bound
states in light-front QCD is explicitly achieved. Finally, the scale dependence
of the effective coupling constant is analytically calculated and the
similarity renormalization group $\beta$ function is determined, from which the
running coupling constant in small momentum transfer is given qualitatively by
$\overline{\alpha}(Q^2) \sim {\Lambda_{QCD}^2 \over Q^2}$. Such a running
coupling constant is the basic assumption in the successful Richardson
$Q\overline{Q}$ potential that ensures the existence of a linear confining
potential at large distance, but now can be obtained from light-front QCD.


title:
Radiatively Generated Parton Distributions of Polarized Hadrons and
  Photons

abstract:
  A next-to-leading order QCD analysis of spin asymmetries and structure
functions in polarized deep inelastic lepton nucleon scattering is presented
within the framework of the radiative parton model. The $Q^2$-dependence of the
spin asymmetry $A_1^{p}(x,Q^2)$ is shown to be non-negligible for $x$-values
relevant for the analysis of the present data. In the second part of the paper
we present LO results for radiatively generated spin-dependent parton
distributions of the photon and for its structure function $g_1^{\gamma}$.


title: Quantum statistics and Altarelli-Parisi evolution equations

abstract:
  The phenomenological evidence of quantum statistical effects in parton
physics is here briefly summarized, and the recent good results obtained by
parameterizing the parton distributions in terms of Fermi-Dirac and
Bose-Einstein statistical functions are discussed. In this framework we study
the modification of the scaling behaviour of parton distributions due to
quantum statistical effects. In particular, by following a well-known formal
analogy which holds between the Altarelli-Parisi evolution equations, at
leading-log approximation, and a set of Boltzmann equations, we suggest a
generalization of evolution equations to take into account Pauli exclusion
principle and gluon induced emission.


title:
Degenerate BESS Model: The possibility of a low energy strong
  electroweak sector

abstract:
  We discuss possible symmetries of effective theories describing spinless and
spin 1 bosons, mainly to concentrate on an intriguing phenomenological
possibility: that of a hardly noticeable strong electroweak sector at
relatively low energies. Specifically, a model with both vector and axial
vector strong interacting bosons may possess a discrete symmetry imposing
degeneracy of the two sets of bosons (degenerate BESS model). In such a case
its effects at low energies become almost invisible and the model easily passes
all low energy precision tests. The reason lies essentially in the fact that
the model automatically satisfies decoupling, contrary to models with only
vectors. For large mass of the degenerate spin one bosons the model becomes
identical at the classical level to the standard model taken in the limit of
infinite Higgs mass. For these reasons we have thought it worthwhile to fully
develop the model, together with its possible generalizations, and to study the
expected phenomenology. For instance, just because of its invisibility at low
energy, it is conceivable that degenerate BESS has low mass spin one states and
gives quite visible signals at existing or forthcoming accelerators.


title: Singlet-Higgs-Boson Signals at Hadron Colliders

abstract:
  Many extensions of the Standard Model include $SU(2)_L \times U(1)_Y$ singlet
higgs bosons, $h^0$, and also vectorlike fermions which couple to it. The
production and detection possibilities of such singlet neutral scalars at
hadron colliders are considered for different scenarios of vectorlike fermions.
We find that for some values of masses and couplings, detection at the CERN
Large Hadron Collider (LHC) appears to be a distinct possibility, while at the
Fermilab Tevatron upgrade the $h^0$ might be observed only in very favourable
circumstances.


title: New results of the Berliner relativistic quark model

abstract:
  It is pointed out that the recently measured left-right asymmetries in
inclusive pion and lambda hyperon production processes are in very good
agreement with the relativistic quark model, proposed some time ago. Further
predictions based on this model for hyperon productions, for lepton pair
productions and for W/Z-boson productions are also presented.


title: Cosmic Electroweak Strings

abstract:
  We examine the Standard Model field configurations near cosmic strings in a
particular class of models. This class is defined by the condition that the
generator of the flux in the string, $T_s$, commutes with the Standard Model
Lie algebra. We find that if the Standard Model Higgs carries a charge $F_h /2$
under $T_s$, cosmic string solutions have Z-flux $\Phi_Z =[n-F_h
N/F_{\phi}]4\pi \cos \theta_w /g$, where $n$ is any integer and $4\pi
N/qF_{\phi}$ is the flux of the gauge field associated with $T_s$. Only the
configuration with the smallest value of $|n-F_h N/F_{\phi}|$ is stable,
however. We argue that the instabilities found at higher $\Phi_Z$ are just
associated with paths in configuration space reducing $|n-F_h N/F_{\phi}|$ by
one unit. This contradicts recent claims that the instabilities in such models
represent the spontaneous generation of current along the string. We also show
that the stable strings have no Standard Model fermion zero modes: therefore
there is no possibility of supercurrents carried by Standard Model particles in
this class of models.


title:
S-matrix approach to two-pion production in e^+e^- annihilation and tau
  decay

abstract:
  Based on the S-matrix approach, we introduce a modified formula for the
$\pi^{\pm}$ electromagnetic form factor which describes very well the
experimental data in the energy region $2m_{\pi} \leq \sqrt{s} \leq 1.1$ GeV.
Using the CVC hypothesis we predict $B(\tpp) = (24.75 \pm 0.38)\% $, in
excellent agreement with recent experiments.


title:
Constraint on the QED Vertex from the Mass Anomalous Dimension $\gamma_m
  = 1$

abstract:
  We discuss the structure of the non-perturbative fermion-boson vertex in
quenched QED. We show that it is possible to construct a vertex which not only
ensures that the fermion propagator is multiplicatively renormalizable, obeys
the appropriate Ward-Takahashi identity, reproduces perturbation theory for
weak couplings and guarantees that the critical coupling at which the mass is
dynamically generated is gauge independent but also makes sure that the value
for the anomalous dimension for the mass function is strictly 1, as Holdom and
Mahanta have proposed.


title: Ultraviolet renormalons in abelian gauge theories

abstract:
  We analyze the large-order behaviour in perturbation theory of classes of
diagrams with an arbitrary number of chains (i.e. photon lines, dressed by
vacuum polarization insertions). We derive explicit formulae for the leading
and subleading divergence as $n\to\infty$, and a complete result for the vacuum
polarization at the next-to-leading order in $1/N_f$. In general, diagrams with
more chains yield stronger divergence. We define an analogue of the familiar
diagrammatic $R$-operation, which extracts ultraviolet renormalon counterterms
as insertions of higher-dimension operators. We then use renormalization group
equations to sum the leading $(\ln n/N_f)^k$-corrections to all orders in
$1/N_f$ and find the asymptotic behaviour in $n$ up to a constant that must be
calculated explicitly order by order in $1/N_f$.


title: Status of High Energy Foward Elastic Scattering

abstract:
  We present the results of fitting all data for $pp$ and $\bar pp$ scattering
at $\sqrt s \geq 9.7$ Gev and up to the collider energy with various analytic
parametrizations of the elastic forward scattering amplitudes based on the
derivative dispersion relation. It is found that the model containing the
Pomeron and Reggeon terms with 8 parameters has the most preferred
$\chi^2/d.o.f = 1.3$, while the Donnachie and Landshoff model with 5 parameters
has $\chi^2/d.o.f = 2.16$ for a data set of 111 experimental points. The
current data however make no clear preference between the $\ell n s$ and $\ell
n^2 s$ type Pomerons.


title:
$R$-Parity Violation in Flavor Changing Neutral Current Processes and
  Top Quark Decays

abstract:
  We show that supersymmetric $R$-parity breaking ($\not R_p$) interactions
always result in Flavor Changing Neutral Current (FCNC) processes. Within a
single coupling scheme, these processes can be avoided in either the charge
$+2/3$ or the charge $-1/3$ quark sector, but not both. These processes are
used to place constraints on \Rp couplings. The constraints on the first and
the second generations are better than those existing in the literature. The
\Rp interactions may result in new top quark decays. Some of these violate
electron-muon universality or produce a surplus of $b$ quark events in
$t\bar{t}$ decays. Results from the CDF experiment are used to bound these \Rp
couplings.


title: Chiral Symmetry and the Constituent Quark Model

abstract:
  New results on baryon structure and spectrum developed in collaboration with
Dan Riska [1-4] are reported. The main idea is that beyond the chiral symmetry
spontaneous breaking scale light and strange baryons should be considered as
systems of three constituent quarks with an effective confining interaction and
a chiral interaction that is mediated by the octet of Goldstone bosons
(pseudoscalar mesons) between the constituent quarks.


title:
Mutual cosideration of $b\to s\gamma$ and $\mu\to e\gamma$ in
  supersymmetric SO(10) grand unification

abstract:
  We compare the branching ratios for $b\rightarrow s\gamma$ and
$\mu\rightarrow e\gamma$ in terms of constraining the parameter space in
supersymmetric SO(10) grand unification models where supersymmetry is broken
softly near the Planck scale by generationally symmetric operators. We observe
two general cases. One with small $\tan\beta =2$ and the other one with large
$\tan\beta$ having third generation Yukawa coupling unification at the GUT
scale. \newline\indent We show that for small $\tan\beta$ the branching ratio
constraints allow only a smaller region of parameter space for $\mu>0$ compared
to $\mu<0$ for gluino mass $\alt$ 500 GeV.
  With large $\tan\beta$, we find acceptable regions of parameter space with
$\left|\mu \right|\alt 1$ TeV only for $\mu<0$. The dominant constraint on
large $\tan\beta$ with $\mu >0$ parameter space is found to be given by the
$b\rightarrow s\gamma$ branching ratio, while for large $\tan\beta$ with $\mu
<0$ it is found to be given by the $\mu\rightarrow e\gamma$ branching ratio. In
many of these acceptable regions, we find that the $\mu\rightarrow e\gamma$
branching ratio is predicted to be within one order of magnitude of its current
experimental bound. We also show that the usually neglected gluino mediated
diagrams in $b\rightarrow s\gamma$ can not be ignored in some regions of
parameter space, especially for large $\tan\beta$ scenarios when the gluino
mass is near its lower experimental bound.


title:
Suppression of Proton Decay in the Missing-Partner Model for
  Supersymmetric SU(5) GUT

abstract:
  The Peccei-Quinn symmetric extension of the missing-partner model in the
supersymmetric SU(5) grand unified model is consistent with the observed
stability of the proton, even in the large $\tan\beta$ region ($\simeq 50-60$)
expected from the Yukawa unification. Moreover, the SU(5) gauge coupling
constant remains small enough for the perturbative description of GUT's below
the gravitational scale.


title: Leptoquark Production in $e^-e^-$ Scattering

abstract:
  We consider the production of scalar and vector leptoquarks in $e^-e^-$
collisions. Although this reaction is not competitive with {\em e.g.}
$e^-\gamma$ scattering for discovering these heavy states, it is the main
process susceptible of differentiating two important classes of leptoquarks.


title: Light-Heavy Symmetry: Geometric Mass Hierarchy for Three Families

abstract:
  The Universal Seesaw pattern coupled with a Light$\leftrightarrow$Heavy
symmetry principle leads to the Diophantine equation $\displaystyle N =
\sum_{i=1}^Nn_i$, where $n_i\geq 0$ and distinct. Its unique non-trivial
solution $(3=0+1+2)$ gives rise to the geometric mass hierarchy $m_W$,
$m_W\epsilon$, $m_W\epsilon^2$ for $N=3$ fermion families. This is realized in
a model where the hybrid (yet Up$\leftrightarrow$Down symmetric) quark mass
relations $m_d m_t \approx m_c^2\leftrightarrow m_u m_b \approx m_s^2 $ play a
crucial role in expressing the CKM mixings in terms of simple mass ratios,
notably $\sin\theta_C \approx {m_c\over m_b}$.


title: Double Scaling of Angular Correlations inside Jets

abstract:
  Angular correlations of partons have been derived for high energy jets in
QCD. Interesting new scaling properties with two redundant variables (jet
energy $P$ and jet opening angle $\Theta$) emerge which can be tested within a
parton-hadron duality picture. Recent results from LEP support the scaling in
$\Theta$; the scaling in both $P$ and $\Theta$ could be tested with jets from
deep inelastic scattering or with high $p_T$ jets.


title:
Twist-three distributions and their appearance in the doubly-polarized
  Drell-Yan process

abstract:
  The twist-three distributions $g_2(x)$ and $h_2(x)$ are defined as
quark-field matrix elements between polarized hadron states. They can be
written in terms of quark-mass and gluonic operators, after which the
Burkhardt-Cottingham sum rule for $g_2$ can be derived and a similar sum rule
for $h_2$. Their role in the Drell-Yan double-spin asymmetry $A_{LT}$ is
explained.


title: Theoretical Review of Radiative Rare B Decays

abstract:
  A status report on the theory of radiative rare $B$ decays in the standard
model is presented, with focus on inclusive decays $B \rightarrow X_{(s,d)}\,
\gamma$ and exclusive decays $B \rightarrow (K^\ast,\omega,\rho) \, \gamma$. CP
asymmetries are also briefly discussed.


title: The Radiative Charmed Baryon Decay $\Xi_{c2}^{0*} \to \Xi_{c1}^0 \gamma$

abstract:
  V-spin symmetry ($s \leftrightarrow d$ symmetry) forbids the radiative decay
$\Xi_{c2}^{0*} \rightarrow \Xi_{c1}^0 \gamma$ in the SU(3) limit. The quark
mass term breaks V-spin symmetry and the leading nonanalytic contribution to
the radiative decay amplitude is computable in heavy baryon chiral perturbation
theory. The radiative decay branching ratio is determined by the coupling
constant $g_2$ and at leading order in chiral perturbation theory is given by
$Br(\Xi_{c2}^{0*} \rightarrow \Xi_{c1}^0 \gamma) = 1.0\times 10^{-3} g_2^2$.
Measurement of this branching fraction will determine $|g_2|$.


title:
A Next-to-Leading Determination of the Singlet Axial Charge and the
  Polarized Gluon Content of the Nucleon

abstract:
  We perform a full next-to-leading analysis of the the available experimental
data on the polarized structure function g_1 of the nucleon, and give a precise
determination of its singlet axial charge together with a thorough assessment
of the theoretical uncertainties. We find that the data are now sufficient to
separately determine first moments of the polarized quark and gluon
distributions, and show in particular that the gluon contribution is large and
positive.


title: Searching for $B_c$ mesons in the ATLAS experiment at LHC

abstract:
  We discuss the feasibility of the observation of the signal from $B_c$ mesons
in the ATLAS experiment at the LHC. In particular, we address the decay mode
$B_c{\rightarrow}J/\psi \pi$ followed by the leptonic decay
$J/\psi{\rightarrow}\mu^+\mu^-$, which should permit an accurate measurement of
the $B_c$ mass. We performed a Monte Carlo study of the signal and background
concluding that a precision of $\approx$ 1 MeV for the $B_c$ mass could be
achieved after one year of running at $\lq\lq$low" luminosity. The semileptonic
decay $B_c{\rightarrow}J/\psi\ {\mu}^+{\nu}_{\mu}$ is also considered for a
possible extraction of ${\mid}V_{cb}{\mid}$.


title: Fonctions de structure polarisees

abstract: This is a pedagogical review on polarized structure functions .


title: The Nucleon's Antiquark Sea: A Virtual Meson Cloud or Gluons?

abstract:
  We study the possible contribution of the nucleon's virtual meson cloud to
the sea quark distribution as observed in deep inelastic lepton scattering. We
adjust the meson-nucleon cut-offs to the large-x tails of the antiquark
distributions, find qualitatively different behavior in the flavor singlet and
non-singlet channels and study the scale dependence of our results. We
demonstrate that, within convolution models, to reproduce the sea quark
distribution the relevant pion momenta should be around 0.8 GeV.


title: Baryon masses at second order in large-$N$ chiral perturbation theory

abstract:
  We consider flavor breaking in the the octet and decuplet baryon masses at
second order in large-$N$ chiral perturbation theory, where $N$ is the number
of QCD colors. We assume that $1/N \sim 1/N_F \sim m_s / \Lambda \gg
m_{u,d}/\Lambda, \alpha_{EM}$, where $N_F$ is the number of light quark
flavors, and $m_{u,d,s} / \Lambda$ are the parameters controlling $SU(N_F)$
flavor breaking in chiral perturbation theory. We consistently include
non-analytic contributions to the baryon masses at orders $m_q^{3/2}$, $m_q^2
\ln m_q$, and $(m_q \ln m_q) / N$. The $m_q^{3/2}$ corrections are small for
the relations that follow from $SU(N_F)$ symmetry alone, but the corrections to
the large-$N$ relations are large and have the wrong sign. Chiral
power-counting and large-$N$ consistency allow a 2-loop contribution at order
$m_q^2 \ln m_q$, and a non-trivial explicit calculation is required to show
that this contribution vanishes. At second order in the expansion, there are
eight relations that are non-trivial consequences of the $1/N$ expansion, all
of which are well satisfied within the experimental errors. The average
deviation at this order is $7 \MeV$ for the $\De I = 0$ mass differences and
$0.35 \MeV$ for the $\De I \ne 0$ mass differences, consistent with the
expectation that the error is of order $1/N^2 \sim 10\%$.


title:
Probing the polarized gluon content of the proton through $ \chi_2$
  hadroproduction

abstract:
  Determining how much spin is carried by gluon in a polarized proton is a
fundamental problem which cannot be resolved by completely inclusive deep
inelastic measurements. Hadroproduction of heavy flavors is very sensitive to
the gluon content of hadrons. We show that $\chi_2 (3555)$ production in
polarized proton-proton collisions is a good candidate reaction to address this
challenging question.


title: Limits on Non-Standard Top Quark Couplings from Electroweak Measurements

abstract:
  We calculate the typical size of loop corrections to electroweak observables
arising from non-standard $Z {\overline t } t$ and $W t b$ vertices. We use an
effective Lagrangian formalism based on the electroweak gauge group
$SU(2)_L\times U(1)_Y \rightarrow U(1)_{EM}$. Limits on the non-standard model
top quark couplings from electroweak observables are presented and compared
with previously obtained limits.


title:
The $\msbar$ Renormalized Bottom Mass of Order ${\cal O}(\alpha_s G_F
  M_t^2)$ and its Application to $\Gamma(H\to b\bar{b})$

abstract:
  The renormalized mass of the bottom quark is calculated at the two loop level
to order ${\cal O}(\alpha_s G_F M_t^2)$ in the $\msbar$ renormalization scheme.
Different strategies for the computation are outlined. The result is applied to
the partial decay rate $\Gamma(H\rightarrow b\bar{b})$ of the Higgs boson into
bottom quarks. Expressing the width in terms of the running mass instead of the
bottom pole mass allows to treat the ${\cal O}(\alpha_s G_F M_t^2)$ radiative
corrections on the same footing as is commonly used in pure QCD calculations.
The numerical values for the corrections are given and the sizes of different
contributions are compared.


title: Double gluon fragmentation to $J/\psi$ pairs at the Tevatron

abstract:
  It has been proposed that the large cross sections for prompt $\psi$,
$\psi'$, and $\chi_c$ production at the Fermilab Tevatron $p\bar p$ collider
can be explained by a dominant color-octet term in the fragmentation function
for a gluon to split into quarkonium. We show that this mechanism makes
testable predictions for double-quarkonium $\psi\psi$, $\psi\psi'$,
$\psi\chi_c$, $\psi\Upsilon$ and $\psi\chi_b$ production, as well as for $W
\psi$ production, using color-octet matrix elements previously determined from
charmonium production data. The $\psi\psi$ signal would already be measurable
at the Tevatron, while the $\psi\chi_c$ and $W\psi$ signals would be on the
edge of present detectability.


title: Supersymmetry Phenomenology: A Microreview

abstract:
  We briefly review the current status and future prospects for supersymmetry
searches at colliders, and discuss strategies by which further information
about sparticle properties may be obtained at the LHC.


title: Majorana -- like models in the physics of neutral particles

abstract:
  Due to the standard electroweak model we have become accustomed to think
about a neutrino $\nu$ and its antineutrino $\bar \nu$ as distinct particles.
However, it has long been recognized that the apparent distinction between them
may be only an illusion. Implying these words of Prof. B. Kayser we give an
alternative insight in the physics of neutral particles (neutrino and photon).
The proposed formalism which is based on the Majorana ideas could also be
useful for deeper understanding of the nature of electron.


title:
The Role of Strange and Charm Quarks in the Nucleon Spin Structure
  Function

abstract:
  We perform an analysis of the relation between the factorization scale and
the masses of the quarks in the calculation of the hard gluon coefficient in
polarized deep inelastic scattering. Particular attention is paid to the role
of strange and charm quarks at finite momentum transfer. It is found that for
the momentum transfer of the present experiments, the contribution from the
charm quark is significant.


title: Can Decaying Particles Raise the Upperbound on the Peccei-Quinn Scale?

abstract:
  We have reexamine the effect of entropy production on the cosmic axion
density and find that the Peccei-Quinn scale $F_a$ larger than about
$10^{15}$~GeV is not allowed even if large entropy is produced by the decays of
coherent oscillations or non-relativistic massive particles. We stress that
this result is independent of the details of models for the decaying particles.


title: Study of Single-Spin Asymmetry in Diffractive High- $p_t$-Jet Production

abstract:
  It is shown that the transverse single spin asymmetry in polarized
diffractive $Q \bar Q$ production depends strongly on the spin structure of the
pomeron coupling. It is concluded that the spin properties of quark-pomeron and
proton-pomeron vertices can be studied in future HERA-N experiments.


title:
Phase Structure of a Four-Fermion Theory at Finite Temperature and
  Chemical Potential

abstract:
  We discuss the chiral symmetry restoration at high temperature and chemical
potential for a four-fermion interaction theory in arbitrary dimensions ($2\leq
D<4$). To investigate the ground state of the theory we calculate the effective
potential and the gap equation using the method of the $1/N$ expansion. We
study the phase structure at finite temperature and chemical potential and show
critical curves which divide the symmetric and asymmetric phase. We find that
the first and second order phase transition coexist for $2\leq D \leq 3$
depending on the value of the temperature and chemical potential. On the other
hand only the second order phase transition is realized for $3<D<4$. We also
present the critical behavior of the dynamically generated fermion mass. (Talk
presented at the Fourth International Workshop on Thermal Field Theory and
Their Application, Dalian, P. R. China, 5--10 August, 1995.)


title: Thermal Field Theory in Non-Equilibrium States

abstract:
  Conventional transport theory is not really applicable to non-equilibrium
systems which exhibit strong quantum effects. We present two different
approaches to overcome this problem. Firstly we point out how transport
equations may be derived that incorporate a nontrivial spectral function as a
typical quantum effect, and test this approach in a toy model of a strongly
interacting degenerate plasma. Secondly we explore a path to include
non-equilibrium effects into quantum field theory through momentum mixing
transformations in Fock space. Although the two approaches are completely
orthogonal, they lead to the same coherent conclusion.


title:
Multiplicity distributions in a thermodynamical model of hadron
  production in $e^+e^-$ collisions

abstract:
  Predictions of a thermodynamical model of hadron production for multiplicity
distributions in $e^+e^-$ annihilations at LEP and PEP-PETRA centre of mass
energies are shown. The production process is described as a two-step process
in which primary hadrons emitted from the thermal source decay into final
observable particles. The final charged tracks multiplicity distributions turn
out to be of Negative Binomial type and are in quite good agreement with
experimental observations. The average number of clans calculated from fitted
Negative Binomial coincides with the average number of primary hadrons
predicted by the thermodynamical model, suggesting that clans should be
identified with primary hadrons.


title:
W-Pair Production in the Process $e^+e^- \to \ell \nu q\bar{q}'$ and
  Measurement of the $WW\gamma$ and $WWZ$ Couplings

abstract:
  We performed a detailed analysis of the process $e^+e^-\to \ell \nu
q\bar{q}'$ where we included all tree level Feynman diagrams that contribute to
this final state. We studied the sensitivity of this process to anomalous
trilinear gauge boson couplings of the $WW\gamma$ and $WWZ$ vertices using two
popular parametrizations. We used a maximum likelihood analysis of a five
dimensional differential cross-section based on the $W$ and $W$ decay product
angular distributions. We concentrated on LEP-200 energies, taking
$\sqrt{s}=175$ GeV, and energies appropriate to the proposed Next Linear
Collider (NLC), a high energy $e^+e^-$ collider with center of mass energies
$\sqrt{s}=500$ and 1~TeV. At 175 GeV, $g_1^Z$ can be measured to about $\pm
0.2$, $\kappa_Z$ to $\pm 0.2$ and $\kappa_\gamma$ to $\pm 0.3$, $\lambda_Z$ to
$\pm 0.2$ and $\lambda_\gamma$ to $\pm 0.3$. at 95\% C.L. assuming
500~pb$^{-1}$ integrated luminosity. Although these will be improvements of
existing measurements they are not sufficiently precise to test the standard
model at the loop level and are unlikely to see deviations from SM
expectations. At 500~GeV with 50~fb$^{-1}$ integrated luminosity, $g_1^Z$ can
be measured to about $\pm 0.01$, $\kappa_Z$ and $\kappa_\gamma$ to $\pm 0.005$
and $\lambda_Z$ and $\lambda_\gamma$ to $\pm 0.003$ at 95\% C.L. while at 1 TeV
with 200~fb$^{-1}$ integrated luminosity, $\kappa_V$ and $\lambda_V$ can be
measured to about $\pm 0.005$ and $\pm 10^{-3}$ respectively. The 500~GeV
measurements will be at the level of loop contributions to the couplings and
may show hints of new physics while the 1~TeV should be sensitive to new
physics at the loop level.


title:
Study of sigma(750) and rho0(770) production in measurements of
  piN(polarized) -> pi(+)pi(-)n on a polarized target at 5.98,11.85 and 17.2
  GeV/c

abstract:
  We present a new and improved model independent amplitude analysis of
reactions $\pi^+ n_\uparrow \to \pi^+ \pi^- p$ at 5.98 and 11.85 GeV/c and
$\pi^- p_\uparrow \to \pi^- \pi^+ n$ at 17.2 GeV/c measured with transversely
polarized targets at the CERN Proton Synchrotron. A clear signal for
$\sigma(750)$ resonance emerges in all four solutions for $S$-wave intensity
$I_S$ at 5.98 and 11.85 GeV/c and in both solutions for $S$-wave amplitude
$|\overline S|^2\Sigma$ at 17.2 GeV/c. Its $\pi^+\pi^-$ decay width is
estimated to be in the range 200--300 MeV. We find significant suppression of
$\rho^0$ production in the amplitudes $|U|^2\Sigma$, $|\overline N |^2\Sigma$
and, at 17.2 GeV/c, in $|L|^2\Sigma$. The mass dependence of amplitudes
$|\overline L |^2\Sigma$ and $|L|^2\Sigma$ shows unexpected structures within
the $\rho^0$ mass region which correlate the mass spectra corresponding to
opposite nucleon spins. These features of $P$-wave moduli reveal the essential
role of nucleon spin in pion production process and contradict the
factorization hypothesis. Our results emphasize the need for a systematic study
of pion production on the level of amplitudes in a new generation of dedicated
experiments with spin at the recently proposed high-intensity hadron
facilities.


title: Strongly-Interacting Electroweak Sector --Model Independent Approaches--

abstract:
  Phenomenology of a strongly-interacting electroweak symmetry breaking sector
at current and future colliders is reviewed.


title: Precision Experiments, Grand Unification, and Compositeness

abstract:
  Precision electroweak data allow one to test the standard model, constrain
its parameters, and search for the effects of some kinds of new physics. The
results of the most recent data from LEP, SLC, and elsewhere are described, as
are their predictions for $m_t$, $M_H$, and $\alpha_s$. The implications for
the two major classes of extensions of the standard model,
supersymmetry/unification and compositeness, are described.


title: Hard thermal loop resummation techniques in hot gauge theories

abstract:
  A review is given of the hard thermal loop resummation methods initiated by
Braaten, Pisarski, and others. We describe some successes of these techniques
as well as instances where modifications are necessary. Some possible
directions where these modifications may lead are also discussed. [Review talk
given at the 4th workshop on thermal field theories held in Dalian, China]