title: Particle and Nuclear Physics with High Energy Leptons

abstract:
  In high centre-of-mass energy lepton-nucleon collisions the space-time time
resolution of partonic processes can be {\it fine-tuned} within a dynamical
range which is unattainable in hadronic collisions. Replacing nucleons by
nuclei of variable atomic number enables one to tune the strength of colour
forces. The experimental program of high energy electron-nucleon and its
extension to electron-nucleus collisions should thus give an unique opportunity
to experimentally explore the transition between the soft and hard interactions
of small and extended partonic systems. Such an experimental program, which can
be realized at DESY and/or BNL with relatively modest cost, is discussed in
this talk.


title:
Mass shift, width broadening and spectral density of rho-mesons produced
  in heavy ion collisions

abstract:
  Our recent work on modifications of rho-mesons formed at the last stage of
evolution of hadronic matter produced in heavy ion collisions is summarized. It
is found that while the mass shift is on the order of a few tens of MeV, the
width and spectral density become so broad that rho may lose its identity as a
well defined resonance.


title: Orbitally Excited Baryons in Large N_c QCD

abstract:
  We present a model-independent analysis of the mass spectrum of nonstrange
l=1 baryons in large N_c QCD. The 1/N_c expansion is used to select and order a
basis of effective operators that spans the nine observables (seven masses and
two mixing angles). Comparison to the data provides support for the validity of
the 1/N_c expansion, but also reveals that only a few nontrivial operators are
strongly preferred. We show that our results have a consistent interpretation
in a constituent quark model with pseudoscalar meson exchange interactions.


title: Concatenation of Scales Below 1 eV

abstract:
  There are (at least) four numbers of physical and cosmological significance
whose inferred values, when expressed in mass units, cluster in a window below
1 eV. These are: the neutrino mass, the neutrino chemical potential, the
cosmological constant, and the size of two extra dimensions (if the fundamental
scale of gravity is 1-10 TeV). In this note, we imagine ways in which these
four numbers could all be connected.


title: Triviality and the Precision Bound on the Higgs Mass

abstract:
  The triviality of the scalar sector of the standard one-doublet Higgs model
implies that this model is only an effective low-energy theory valid below some
cut-off scale Lambda. For a heavy higgs this scale must be relatively low (10
TeV or less). Additional interactions coming from the underlying theory, and
suppressed by the scale Lambda, give rise to model-dependent corrections to
precisely measured electroweak quantities. Dimension six operators arising from
the underlying physics naturally contribute to the S and T parameters, and
their effects should be included in a global fit to the precision data that
determines any limit on the Higgs mass. Using dimensional analysis, we estimate
the expected size of these corrections in a custodially-symmetric
strongly-interacting underlying theory. Taking these operators' coefficients to
be of natural size gives sufficiently large contributions to the T parameter to
reconcile Higgs masses as large as 400-500 GeV with the precision data.


title: Zeros, Dips and Signs in pp and p$\rm\bf\bar p$ Elastic Amplitudes

abstract:
  The dips observed in the differential cross sections of elastic pp and
p$\bar{\rm p}$ scattering are studied in terms of the locations of the zeros of
the real and imaginary parts of the amplitude and of the sign of real part at
large $|t|$. It is confirmed that the differences in shapes of the dips in the
pp and p$\bar{\rm p}$ systems are determined by a change of sign of the real
tail, which seems to be determined by perturbative QCD contributions.


title: Generalized dipole polarizabilities of the pion

abstract:
  We discuss the virtual Compton scattering amplitude $\gamma^\ast+\pi\to
\gamma+\pi$ which enters the reaction $\pi^-+e^-\to\pi^-+e^-+\gamma$. The
low-energy scattering amplitude is divided into a model-independent part,
involving only the electromagnetic form factor, and a residual part which
contains structure information related specifically to (virtual) Compton
scattering. In the limit of vanishing final-photon energy, the residual
amplitude can be expressed in terms of three generalized dipole
polarizabilities which are functions of the squared virtual-photon
four-momentum. We study the VCS amplitude in the framework of chiral
perturbation theory at ${\cal O}(p^4)$. At the one-loop level the generalized
dipole polarizabilities are degenerate
$\alpha_L(q^2)=\alpha_T(q^2)=-\beta(q^2)$.


title: Omega Meson Cloud and the Proton's Light Anti-Quark Distribution

abstract:
  We use the meson cloud model of the nucleon to calculate distribution
functions for $(\bar {d} - \bar{u})$ and $ \bar{d}/\bar{u}$ in the proton.
Including the effect of the omega meson cloud, with a coupling constant
$g_\omega^2/4\pi\approx 8$, allows a reasonably good description of the data.


title:
Analytic Form of the One-loop Vertex and of the Two-loop Fermion
  Propagator in 3-Dimensional Massless QED

abstract:
  We evaluate the analytic expression for the one-loop fermion-boson vertex in
massless QED3 in an arbitrary covariant gauge. The result is written in terms
of elementary functions of its momenta. The vertex is decomposed into a
longitudinal part, that is fully responsible for ensuring the Ward and
Ward-Takahashi identities are satisfied, and a transverse part. Following Ball
and Chiu and K{\i}z{\i}lers\"{u} {\it et. al.}, the transverse part is written
in its most general form as a function of 4 independent vectors. We calculate
the coefficients of each of these vectors. We also check the transversality
condition to two loops and evaluate the fermion propagator to the same order.
We compare our results with a conjecture of the non-perturbative vertex by
Tjiang and Burden.


title: Inverse neutrinoless double beta decay (and other Delta L=2 processes)

abstract:
  I review the prospects for the detection of Delta L=2 processes at future
colliders. Except in contrived models, the process e- e- -> W- W- is
unobservable at future linear colliders unless $\sqrt{s} \gsim 2$ TeV, due to
constraints from neutrinoless double beta decay. As there are no analogous
constraints on the Majorana mass of the $\nu_\mu$, mu- mu- -> W- W- could be
observed at a muon collider with considerably lower $\sqrt{s}$. One can also
consider esoteric processes such as gamma gamma -> mu+ mu+ W- W-. Such
processes may be observable if $\sqrt{s} \gsim 4$ TeV.


title: Renormalization of twist-three operators and integrable lattice models

abstract:
  We address the problem of solution of the QCD three-particle evolution
equations which govern the Q-dependence of the chiral-even quark-gluon-quark
and three-gluon correlators contributing to a number of asymmetries at leading
order and the transversely polarized structure function g_2(x). The
quark-gluon-quark case is completely integrable in multicolour limit and
corresponds to a spin chain with non-periodic boundary conditions, while the
pure gluonic sector contains, apart from a piece in the Hamiltonian equivalent
to XXX Heisenberg magnet of spin s = - 3/2, a non-integrable addendum which can
be treated perturbatively for a bulk of the spectrum except for a few lowest
energy levels. We construct a quasiclassical expansion with respect to the
total conformal spin of the system and describe fairly well the energy spectra
of quark-gluon-quark and three-gluon systems.


title: Neutrino Decay and Atmospheric Neutrinos

abstract:
  We reconsider neutrino decay as an explanation for atmospheric neutrino
observations. We show that if the mass-difference relevant to the two mixed
states \nu_\mu and \nu_\tau is very small (< 10^{-4} eV^2), then a very good
fit to the observations can be obtained with decay of a component of \nu_\mu to
a sterile neutrino and a Majoron. We discuss how the K2K and MINOS
long-baseline experiments can distinguish the decay and oscillation scenarios.


title:
The complementarity of LEP, the Tevatron and the LHC in the search for a
  light MSSM Higgs boson

abstract:
  We study the properties of the Higgs boson sector in the MSSM, putting
special emphasis on radiative effects which can affect the discovery potential
of the LHC, Tevatron and/or LEP colliders. We concentrate on the V b b-bar
channel, with V=Z or W, and on the channels with diphoton final states, which
are the dominant ones for the search for a light Standard Model Higgs boson at
LEP/Tevatron and LHC, respectively. By analyzing the regions of parameter space
for which the searches in at least one of these colliders can be particularly
difficult, we demonstrate the complementarity of these three colliders in the
search for a light Higgs boson which couples in a relevant way to the W and Z
gauge bosons (and hence plays a relevant role in the mechanism of electroweak
symmetry breaking).


title: Identifying the neutrino mass spectrum from a supernova neutrino burst

abstract:
  We study the role that the future detection of the neutrino burst from a
galactic supernova can play in the reconstruction of the neutrino mass
spectrum. We consider all possible 3$\nu$ mass and flavor spectra which
describe the solar and atmospheric neutrino data. For each of these spectra we
find the observable effects of the supernova neutrino conversions both in the
matter of the star and the earth. We show that studies of the electron neutrino
and anineutrino spectra as well as observations of the neutral current effects
from supernova will allow us (i) to identify the solar neutrino solution, (ii)
to determine the type of mass hierarchy (normal or inverted) and (iii) to probe
the mixing $|U_{e3}|^2$ to values as low as $10^{-4} - 10^{-3}$.


title: B_c Production at RHIC as a Signal for Deconfinement

abstract:
  The B_C meson is the bound state of b-cbar whose recent detection is the
first step toward completion of the spectroscopy of heavy quark mesonic states.
The b-c states have properties that conveniently fill the gap between the J/Psi
and Upsilon states. Thus it is probable that at RHIC the B_c mesons will serve
as a probe of deconfined matter. We find that significant differences arise for
B_c formation in deconfined and confined matter. Our initial calculations
suggest that: (a) The rates of normal hadronic production mechanisms at RHIC
energies are not sufficient to produce a detectable number of B_c mesons, (b)
If a region of deconfined quarks and gluons is formed, the production (and
survival) rate can be enhanced by several orders of magnitude, and (c) The
observation of B_c mesons at RHIC would signal a source of deconfined charmed
quarks, and the rate of B_c production will be a measure of the initial density
and temperature of that source.


title: Measuring CP Violating Phases at a Future Linear Collider

abstract:
  At a future Linear Collider one will be able to determine the masses of
charginos and neutralinos and their pair production cross sections to high
accuracies. We show how systematically including the cross sections into the
analysis improves the measurement of the underlying mass parameters, including
potential CP violating phases. In addition, we investigate how experimental
errors will affect the determination of these parameters. We present a first
estimate on the lower limit of observable small phases and on the accuracy in
determining large phases.


title: Practical Algebraic Renormalization

abstract:
  A practical approach is presented which allows the use of a non-invariant
regularization scheme for the computation of quantum corrections in
perturbative quantum field theory. The theoretical control of algebraic
renormalization over non-invariant counterterms is translated into a practical
computational method. We provide a detailed introduction into the handling of
the Slavnov-Taylor and Ward-Takahashi identities in the Standard Model both in
the conventional and the background gauge. Explicit examples for their
practical derivation are presented. After a brief introduction into the Quantum
Action Principle the conventional algebraic method which allows for the
restoration of the functional identities is discussed. The main point of our
approach is the optimization of this procedure which results in an enormous
reduction of the calculational effort. The counterterms which have to be
computed are universal in the sense that they are independent of the
regularization scheme. The method is explicitly illustrated for two processes
of phenomenological interest: QCD corrections to the decay of the Higgs boson
into two photons and two-loop electroweak corrections to the process $B \to X_s
\gamma$.


title: The O(alpha_em/alpha_s) correction to BR[B -> X_s gamma]

abstract:
  We evaluate the O(alpha_em/alpha_s) correction to the rate of B -> X_s gamma
decay, i.e. we resum all the 0[ alpha_em ln M_W^2/m_b^2 x (alpha_s ln
M_W^2/m_b^2)^n ] corrections for n=0,1,2,... Our calculation differs from the
previously available one by that it takes into account the complete relevant
set of operators. The correction is found to be negligible, i.e. it is below
1%, in accordance with the former results.


title: Decays of the Lightest Top Squark

abstract:
  We analyze higher order decay modes of the lightest top squark $\tilde{t}_1$
in the Minimal Supersymmetric extension of the Standard Model (MSSM), where the
lightest SUSY particle (LSP) is assumed to be the neutralino $\chi_1^0$. For
small $\tilde{t}_1$ masses accessible at LEP2 and the Tevatron, we show that
the four-body decay mode into the LSP, a bottom quark and two massless
fermions, $\tilde{t}_1 \ra b \chi_1^0 f\bar{f}'$, can dominate in a wide range
of the MSSM parameter space over the loop-induced decay into a charm quark and
the LSP, $\tilde{t}_1 \ra c \chi_1^0$. This result might affect the
experimental searches on this particle, since only the later signal has been
considered so far.


title: Study of polarized gluon distributions in diffractive reactions at HERA

abstract:
  We consider the dependencies of spin asymmetries in the diffractive $J/\Psi$
and $Q \bar Q$ leptoproduction at HERA energies on the structure of the
pomeron-proton coupling. It is shown that it is difficult to study the spin
structure of the pomeron coupling with the proton from the $A_{ll}$ asymmetry.
The $A_{lT}$ asymmetry is an appropriate object for this investigation.


title: Multiplicity of (Mini-)Jets at Small x

abstract:
  We derive closed expressions for the mean and variance of the (mini-)jet
multiplicity distribution in hard scattering processes at low x. Here
(mini-)jets are defined as those due to initial-state radiation of gluons with
transverse momenta greater than some resolution scale m_R, where Lambda^2 <<
m_R^2 << Q^2, Lambda being the intrinsic QCD scale and Q the momentum transfer
scale of the hard scattering. Our results are valid to leading order in
log(1/x) but include all sub-leading logarithms of Q^2/m_R^2. As an
illustration, we predict the mini-jet multiplicity in Higgs boson production at
the Large Hadron Collider.


title:
ON-SHELL2: FORM based package for the calculation of two-loop
  self-energy single scale Feynman diagrams occurring in the Standard Model

abstract:
  A FORM based package (ON-SHELL2) for the calculation of two loop self-energy
diagrams with one nonzero mass in internal lines and the external momentum on
the same mass shell is elaborated. The algorithm, based on recurrence relations
obtained from the integration-by-parts method, allows us to reduce diagrams
with arbitrary indices (powers of scalar propagators) to a set of master
integrals. The SHELL2 package is used for the calculation of special types of
diagrams. Analytical results for master integrals are collected.


title:
Neutrino mass and magnetic moment in supersymmetry without R-parity in
  the light of recent data

abstract:
  We consider the generation of neutrino Majorana mass and transition magnetic
moment by the lepton-number violating $\lambda$ and/or $\lambda'$ couplings in
R-parity-violating supersymmetric models. We update (and improve) the existing
upper limits on the relevant couplings using the most recent data on neutrino
masses and mixings, indicating also the possible improvement by the GENIUS
project. We study the implication of this update on the induced neutrino
magnetic moment.


title:
Precision determination of the pi-N scattering lengths and the charged
  pi-NN coupling constant

abstract:
  We critically evaluate the isovector GMO sumrule for the charged $\pi N N$
coupling constant using recent precision data from $\pi ^-$p and $\pi^-$d atoms
and with careful attention to systematic errors. From the $\pi ^-$d scattering
length we deduce the pion-proton scattering lengths ${1/2}(a_{\pi ^-p}+a_{\pi
^-n})=(-20\pm 6$(statistic)$ \pm 10$ (systematic))~$\cdot
10^{-4}m_{\pi_c}^{-1}$ and ${1/2}(a_{\pi ^-p}-a_{\pi ^-n})=(903 \pm 14)\cdot
10^{-4}m_{\pi_c}^{-1}$. From this a direct evaluation gives $g^2_c(GMO)/4\pi
=14.20\pm 0.07$(statistic)$\pm 0.13$(systematic) or $f^2_c/4\pi= 0.0786\pm
0.0008$.


title: Experimental Signatures of Fermiophobic Higgs bosons

abstract:
  The most general Two Higgs Doublet Model potential without explicit CP
violation depends on 10 real independent parameters. Excluding spontaneous CP
violation results in two 7 parameter models. Although both models give rise to
5 scalar particles and 2 mixing angles, the resulting phenomenology of the
scalar sectors is different. If flavour changing neutral currents at tree level
are to be avoided, one has, in both cases, four alternative ways of introducing
the fermion couplings. In one of these models the mixing angle of the CP even
sector can be chosen in such a way that the fermion couplings to the lightest
scalar Higgs boson vanishes. At the same time it is possible to suppress the
fermion couplings to the charged and pseudo-scalar Higgs bosons by
appropriately choosing the mixing angle of the CP odd sector. We investigate
the phenomenology of both models in the fermiophobic limit and present the
different branching ratios for the decays of the scalar particles. We use the
present experimental results from the LEP collider to constrain the models.


title: Parametric resonance in neutrino oscillations in matter

abstract:
  Neutrino oscillations in matter can exhibit a specific resonance enhancement
-- parametric resonance, which is different from the MSW resonance.
Oscillations of atmospheric and solar neutrinos inside the earth can undergo
parametric enhancement when neutrino trajectories cross the core of the earth.
In this paper we review the parametric resonance of neutrino oscillations in
matter. In particular, physical interpretation of the effect and the prospects
of its experimental observation in oscillations of solar and atmospheric
neutrinos in the earth are discussed.


title:
Final State Radiative Effects for the Exact O(alpha) YFS Exponentiated
  (Un)Stable W+W- Production At and Beyond LEP2 Energies

abstract:
  We present the LL final state radiative effects for the exact O(alpha) YFS
exponentiated (un)stable WW pair production at LEP2/NLC energies using Monte
Carlo event generator methods. The respective event generator, version 1.12 of
the program YFSWW3, wherein both Standard Model and anomalous triple gauge
boson couplings are allowed, generates n(\gamma) radiation both from the
initial state and from the intermediate W+ W- and generates the LL final state
W decay radiative effects. Sample Monte Carlo data are illustrated.


title:
Phase Equilibration and Magnetic Field Generation in U(1) Bubble
  Collisions

abstract:
  We present the results of lattice computations of collisions of two expanding
bubbles of true vacuum in the Abelian Higgs model with a first-order phase
transition. New time-dependent analytical solutions for the Abelian field
strength and the phase of the complex field are derived from initial conditions
inferred from linear superposition and are shown to be in excellent agreement
with the numerical solutions especially for the case where the initial phase
difference between the bubbles is small. With a step-function approximation for
the initial phase of the complex field, solutions for the Abelian field
strength and other gauge-invariant quantities are obtained in closed form.
Possible extensions of the solution to the case of the electroweak phase
transition and the generation of primordial magnetic fields are briefly
discussed.


title:
Mixing of Charge -1/3 Quarks and Charged Leptons With Exotic Fermions in
  E$_{\rm 6}$

abstract:
  A way is suggested to understand why the average masses of $(d,s,b)$ quarks
are smaller than those of $(u,c,t)$ quarks. In contrast to previously proposed
mechanisms relying on different Higgs boson vacuum expectation values or
different Yukawa couplings, the mass difference is explained as a consequence
of mixing of $(d,s,b)$ with exotic quarks implied by the electroweak-strong
unification group E$_{\rm 6}$.


title:
A Slavnov-Taylor identity and equality of damping rates for static
  transverse and longitudinal gluons in hot QCD

abstract:
  A Slavnov-Taylor identity is derived for the gluon polarization tensor in hot
QCD. We evaluate its implications for damping of gluonic modes in the plasma.
Applying the identity to next to the leading order in hard-thermal-loop
resummed perturbation theory, we derive the expected equality of damping rates
for static transverse and longitudinal (soft) gluons. This is of interest also
in view of deviating recent reports of $\gamma_t(p=0)\neq\gamma_l(p=0)$ based
on a direct calculation of $\gamma_l(p=0)$.


title: Parton distributions in a constituent quark scenario

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


title: Orbital Angular Momentum Parton Distributions in Quark Models

abstract:
  At the low energy, {\sl hadronic}, scale we calculate Orbital Angular
Momentum (OAM) twist-two parton distributions for the relativistic MIT bag
model and for non-relativistic quark models. We reach the scale of the data by
leading order evolution in perturbative QCD. We confirm that the contribution
of quarks and gluons OAM to the nucleon spin grows with $Q^2$, and it can be
relevant at the experimental scale, even if it is negligible at the hadronic
scale, irrespective of the model used. The sign and shape of the quark OAM
distribution at high $Q^2$ may depend strongly on the relative size of the OAM
and spin distributions at the hadronic scale. Sizeable quark OAM distributions
at the hadronic scale, as proposed by several authors, can produce the dominant
contribution to the nucleon spin at high $Q^2$.


title: Polarized Parton Distributions in Light-Front Dynamics

abstract:
  We present a consistent calculation of the structure functions within a
light-front constituent quark model of the nucleon. Relativistic effects and
the relevance of the covariance constraints are analyzed for polarized parton
distributions. Various models, which differ in their gluonic structure at the
hadronic scale, are investigated. The results of the full covariant calculation
are compared with those of a non-relativistic approximation to show the
structure and magnitude of the differences. It is also shown how measurements
of transversity in doubly polarized Drell-Yan lepton pair production are a
clearcut sign of covariance requirements for the spin.


title: Small-Recoil Approximation

abstract:
  In this review we discuss a technique to compute and to sum a class of
Feynman diagrams, and some of its applications. These are diagrams containing
one or more energetic particles that suffer very little recoil in their
interactions. When recoil is completely neglected, a decomposition formula can
be proven. This formula is a generalization of the well-known eikonal formula,
to non-abelian interactions. It expresses the amplitude as a sum of products of
irreducible amplitudes, with each irreducible amplitude being the amplitude to
emit one, or several mutually interacting, quasi-particles. For abelian
interaction a quasi-particle is nothing but the original boson, so this
decomposition formula reduces to the eikonal formula. In non-abelian situations
each quasi-particle can be made up of many bosons, though always with a total
quantum number identical to that of a single boson. This decomposition enables
certain amplitudes of all orders to be summed up into an exponential form, and
it allows subleading contributions of a certain kind, which is difficult to
reach in the usual way, to be computed. For bosonic emissions from a heavy
source with many constituents, a quasi-particle amplitude turns out to be an
amplitude in which all bosons are emitted from the same constituent. For
high-energy parton-parton scattering in the near-forward direction, the
quasi-particle turns out to be the Reggeon, and this formalism shows clearly
why gluons reggeize but photons do not. The ablility to compute subleading
terms in this formalism allows the BFKL-Pomeron amplitude to be extrapolated to
asymptotic energies, in a unitary way preserving the Froissart bound. We also
consider recoil corrections for abelian interactions in order to accommodate
the Landau-Pomeranchuk-Migdal effect.


title: Effects of SO(10) D-Terms on SUSY Signals at the Tevatron

abstract:
  We study signals for the production of superparticles at the Tevatron in
supergravity scenarios based on the Grand Unified group SO(10). The breaking of
this group introduces extra contributions to the masses of all scalars,
described by a single new parameter. We find that varying this parameter can
considerably change the size of various expected signals studied in the
literature, with different numbers of jets and/or charged leptons in the final
state. The ratios of these signal can thus serve as a diagnostic to detect or
constrain deviations from the much--studied scenario where all scalar masses
are universal at the GUT scale. Moreover, under favorable circumstances some of
these signals, and/or new signals involving hard $b-$jets, should be observable
at the next run of the Tevatron collider even if the average scalar mass lies
well above the gluino mass.


title:
Confinement and the analytic structure of the one body propagator in
  Scalar QED

abstract:
  We investigate the behavior of the one body propagator in SQED. The self
energy is calculated using three different methods: i) the simple bubble
summation, ii) the Dyson-Schwinger equation, and iii) the Feynman-Schwinger
represantation. The Feynman-Schwinger representation allows an {\em exact}
analytical result. It is shown that, while the exact result produces a real
mass pole for all couplings, the bubble sum and the Dyson-Schwinger approach in
rainbow approximation leads to complex mass poles beyond a certain critical
coupling. The model exhibits confinement, yet the exact solution still has one
body propagators with {\it real} mass poles.


title:
Grand Unification Scale CP Violating Phases And The Electric Dipole
  Moment

abstract:
  The question of CP violating phases in supersymmetry and electric dipole
moments (EDMs) is considered within the framework of supergravity grand
unification (GUT) models with a light ($\stackrel{<}{\sim}$1 TeV) mass
spectrum. In the minimal model, the nearness of the t-quark Landau pole
automatically suppresses the t-quark cubic soft breaking phase at the
electroweak scale. However, current EDM data require the quadratic soft
breaking phase to be small at the electroweak scale unless tan$\beta$ is small
(tan$\beta\stackrel{<}{\sim}$3), and the EDM data combined with the requirement
of electroweak symmetry breaking require this phase to be both large and highly
fine tuned at the GUT scale unless tan$\beta$ is small. Non minimal models are
also examined, and generally show the same behavior.


title: Modulus Stabilization with Bulk Fields

abstract:
  We propose a mechanism for stabilizing the size of the extra dimension in the
Randall-Sundrum scenario. The potential for the modulus field that sets the
size of the fifth dimension is generated by a bulk scalar with quartic
interactions localized on the two 3-branes. The minimum of this potential
yields a compactification scale that solves the hierarchy problem without fine
tuning of parameters.


title:
Applications of Chiral Perturbation Theory in Reactions with Heavy
  Particles

abstract:
  Effective field theory techniques are used to describe the interaction of
heavy hadrons in a model independent way. Predictability is obtained by
exploiting the symmetries of QCD. Heavy hadron chiral perturbation theory is
reviewed and used to describe $D^*$ decays. The phenomenologically important
$D^*D\pi$ coupling is extracted from data working to first order in the chiral
and heavy quark symmetry breaking parameters. A method is described for
determining $|V_{ub}|$ from exclusive semileptonic $B$ and $D$ decays with 10%
uncertainty. An effective field theory for two-nucleon systems is then
discussed. The large S-wave scattering lengths necessitate expanding around a
non-trivial fixed point. A detailed discussion of the interplay between
renormalization and the power counting is given. In power counting pion
interactions with nucleons it is useful to consider three classes of pion:
potential, radiation, and soft. A power counting for massive radiation is
developed. Finally, it is shown that the leading terms in the effective theory
for nucleon-nucleon interactions are invariant under Wigner's SU(4)
spin-isospin symmetry in the infinite scattering length limit.


title:
Singlet Interacting Neutrinos in the Extended Zee Model and Solar
  Neutrino Transformation

abstract:
  We study the impact of Standard Model singlet neutrinos on neutrino flavor
transformation. We focus on an extension of the Zee model which includes
singlet neutrinos, and find that the best limits on the interactions of the
singlet neutrinos come from astrophysical phenomena. Singlet neutrino-electron
scattering will impact both the mattter enhanced flavor transformation
potential as well as detector cross sections. If electron neutrino - singlet
neutrino oscillations are responsible for the solar neutrino anomaly, then the
limit on the singlet neutrino interaction strength is of order of the weak
interaction scale. Zee model modification of nu_tau - e scattering also impacts
solar neutrino transformation, although this interaction is more tightly
constrained.


title: A Three-Dimensional Calculation of Atmospheric Neutrino Fluxes

abstract:
  We present a three-dimensional calculation of atmospheric neutrino fluxes
using accurate models of the geomagnetic field, hadronic interactions, tracking
and decays. Results are presented for the Super-Kamiokande (SK) and Sudbury
Neutrino Observatory (SNO) sites using the GEANT-FLUKA hadronic code. We make a
comparison with previous one-dimensional calculations and other
three-dimensional results. The recently reported geometrical enhancement of low
energy, horizontal neutrinos is confirmed. The effect on observed leptons is
however, restricted to a small overall increase in flux. We report east-west
asymmetries for each of the neutrino species.


title: Eikonalization and Unitarity Constraints

abstract:
  An extensive generalization of the ordinary and quasi-eikonal methods is
presented for the $pp$ and $\bar pp$ elastic scattering amplitudes, which takes
into account in a phenomenological way all intermediate multiparticle states
involving the crossing even and crossing odd combinations of Reggeons. The
formalism in this version involves a maximum of three parameters corresponding
to the intermediate states which are possible in this configuration. The
unitarity restriction is investigated and particular cases are discussed. An
interesting result that emerges concerns the Odderon trajectory intercept: we
find that unitarity dictates that this quantity {\it must} be below or equal
unity unless a very peculiar equality exists between the coupling of the
particles to the Pomeron and the Odderon.


title: Neutrino Mass and Lepton Number Violation with Charged Scalars

abstract:
  If there exist only three light neutrinos below the weak scale, the neutrino
masses can arise by breaking the lepton number L. One example is the Zee
mechanism for the neutrino masses. We study phenomenological implications of
neutrino masses arising from the L violation through introduction of SU(2) X
U(1) singlet scalars with Q_{em}=1 and 2.


title: Exclusive hadronization in gamma* gamma -> pi pi

abstract:
  We perform a QCD analysis of exclusive two-meson production in gamma* gamma
collisions in the kinematical domain of large photon virtuality Q^2 and small
hadronic invariant mass W^2. In these kinematics the amplitude factorizes into
a perturbative subprocess gamma* gamma -> q qbar and a two-meson distribution
amplitude. This opens the way to study new hadronic matrix elements related
with the physics of hadronization and confinement.


title:
New Time Distributions of D^0-\bar{D}^0 or B^0-\bar{B}^0 Mixing and CP
  Violation

abstract:
  The formulae for D^0-\bar{D}^0 or B^0-\bar{B}^0 mixing and CP violation at
the \tau-charm or B-meson factories are derived, for the case that only the
decay-time distribution of one D or B meson is to be measured. In particular,
we point out a new possibility to determine the D^0-\bar{D}^0 mixing rate in
semileptonic D decays at the \Psi (4.14) resonance; and show that both direct
and indirect CP asymmetries can be measured at the \Upsilon (4S) resonance
without ordering the decay times of two B_d mesons or measuring their
difference.


title:
CP Violation in B_d \to D^+D^-, D^{*+}D^-, D^+D^{*-} and D^{*+}D^{*-}
  Decays

abstract:
  CP asymmetries in B_d \to D^+D^-, D^{*+}D^-, D^+D^{*-} and D^{*+}D^{*-}
decays are investigated with the help of the factorization approximation and
isospin relations. We find that the direct CP violation is governed only by the
short-distance penguin mechanism, while the indirect CP asymmetries in B_d \to
D^{\pm}D^{*\mp} transitions may be modified due to the final-state rescattering
effect. An updated numerical analysis shows that the direct CP asymmetry in
B^0_d vs \bar{B}^0_d \to D^+D^- decays can be as large as 3%. The CP-even and
CP-odd contributions to the indirect CP asymmetry in B^0_d vs \bar{B}^0_d \to
D^{*+}D^{*-} decays are found to have the rates 89% and 11%, respectively. Some
comments on the possibilities to determine the weak phase \beta and to test the
factorization hypothesis are also given.


title: Momentum-Space Topology of Standard Model

abstract:
  The momentum-space topological invariants, which characterize the ground
state of the Standard Model, are continuous functions of two parameters,
generated by the hypercharge and by the weak charge. These invariants provide
the absence of the mass of the elementary fermionic particles in the symmetric
phase above the electroweak transition (the mass protection). All the
invariants become zero in the broken symmetry phase, as a result all the
elementary fermions become massive. Relation of the momentum-space invariants
to chiral anomaly is also discussed.


title: Effective Weak Chiral Lagrangian from the Instanton Vacuum

abstract:
  We present in this talk the recent investigation of the effective weak chiral
Lagrangian within the framework of the instanton-induced chiral quark model.
The low energy constants in leading order $g_8$ and $g_{27}$, and their ratio
are determined. The momentum-dependence of the constituent quark mass turns out
to improve the low energy constants to the great extent, respecting the $\Delta
T=1/2$ enhancement.


title: Neutrino Physics: Theory and Phenomenology

abstract:
  Various issues in neutrino phenomenology are reviewed, including: the
possibility of large mixing angles in various models for neutrino masses,
difficulties for degenerate neutrinos as candidates for hot dark matter,
strategies for discriminating between different oscillation interpretations of
the atmospheric and solar neutrino anomalies, the programme of work for
long-baseline neutrino experiments, and the possible future option of a muon
storage ring as a neutrino factory.


title: Triple Pomeron and Proton Diffraction Dissociation

abstract:
  We consider proton diffraction dissociation in the dipole Pomeron model,
where the Pomeron is represented by a double pole in the $J-$plane, and show
that unitarity can be satisfied without decoupling of the triple Pomeron
vertex. Differential and total diffractive cross sections for the reaction
$\bar{p}+p \to \bar{p}+X$ are analyzed and reproduced in this model.


title: Supersymmetric Electroweak Baryogenesis

abstract:
  We calculate the baryon asymmetry generated at the electroweak phase
transition in the minimal supersymmetric standard model, using a new method to
compute the CP-violating asymmetry in the Higgsino flux reflected into the
unbroken phase. The method is based on a Higgs insertion expansion. We find
that the CP asymmetry at leading order is proportional to the change in $\tan
\beta$ in the bubble wall, which is at most of order $10^{-2}$, while at
next-to-leading order this suppression factor disappears. This result may
enhance the final baryon asymmetry generated during the electroweak phase
transition for small $\Delta \beta (< 10^{-3}$).


title: Jet Quenching in Thin Quark-Gluon Plasmas I: Formalism

abstract:
  The modification and amplification of the gluon angular distribution produced
along with hard jets in nuclear collisions is computed. We consider the limit
of a thin quark-gluon plasma, where the number of rescatterings of the jet and
gluons is small. The focus is on jet quenching associated with the formation of
highly off-shell partons in hard scattering events involving nuclei. The
interference between the initial hard radiation amplitude, the multiple induced
Gunion-Bertsch radiation amplitudes, and gluon rescattering amplitudes leads to
an angular distribution that differs considerably from both the standard DGLAP
evolution and from the classical limit parton cascading. The cases of a single
and double rescattering are considered in detail, and a systematic method to
compute all matrix elements for the general case is developed. A simple power
law scaling of the angular distribution with increasing number of rescatterings
is found and used for estimates of the fractional energy loss as a function of
the plasma thickness.


title:
Signals for the Electroweak Symmetry Breaking Associated with the Top
  Quark

abstract:
  The mechanism of the electroweak symmetry-breaking (EWSB) is studied in the
context of the heavy top quark, whose large mass may provide a clue as to the
mechanism which generates the mass of the $W^\pm$ and $Z$ bosons. As a result,
it seems quite likely that the top quark may be special in the sense that it is
involved in dynamics not experienced by the light fermions. Examples of this
include models such as the top-condensate model in which a bound state of top
quarks condenses, generating both the top mass and the gauge boson masses, and
supersymmetric models in which the large top Yukawa coupling naturally explains
the EWSB by radiatively driving the squared mass of a scalar particle (which is
positive at a large energy scale) negative at low energies. Specific collider
signatures of the third family result from such scenarios, and can be used to
test the hypothesis that the top plays a role in the EWSB. In particular,
single top production, as a measure of the top's weak interactions, provides an
excellent probe of nonstandard top quark properties. The physics of single top
production at hadron colliders is carefully studied, with a particular eye
towards what can be learned from single top, including the signs of new physics
that may show up in the single top rate.


title: Confinement of Higgs bosons from hidden symmetry and convexity

abstract:
  In the full effective potential (EFP) approach, we find that spontaneous
symmetry breaking (SSB) can, with the convexity of the full EFP, lead to the
prediction of the IR confinement of Higgs particles, adding difficulty to the
experimental identification of Higgs particles. The short distance behaviors
remain intact. The whole presentation is given in the understanding that any
QFT becomes UV well defined in a more complete underyling theory according to a
recently proposed strategy.


title:
Deuteron spin oscillation and rotation as a universal method of the N-N
  scattering amplitude study

abstract:
  We consider the effects of the deuteron spin rotation and oscillations at the
matter which is proportional to the real part of the deuteron spin-dependent
forward scattering amplitude. That gives a possibility of a direct measurement
of this quantity. Spin-dependent forward scattering amplitude of the deuteron
on an unpolarized proton is discussed in terms of the Glauber multiscattering
theory. This amplitude is determined by the nucleon rescattering, nonsphericity
of the deuteron and spin-dependent nucleon-nucleon scattering amplitude. Thus
deuteron spin oscillation phenomenon represents a method for N-N scattering
amplitude investigation, including its real part, over a broad energy range.


title: GRSV parton densities revisited

abstract:
  An updated next-to-leading order (NLO) QCD analysis of all presently
available longitudinally polarized deep-inelastic scattering (DIS) data is
presented in the framework of the radiative parton model.


title: Neutrino Masses from Broken R-Parity

abstract:
  We review models where R-parity is broken, either spontaneously or
explicitly. In this last case we consider the situation where R-parity is
broken via bilinear terms in the superpotential. We show that although at tree
level only one neutrino gets mass, at one--loop level all three neutrinos
became massive. We study the conditions under which bimaximal mixing can be
achieved and show that the masses can be in the correct ranges needed for
solving the atmospheric and solar neutrino problems.


title:
Probing the parton densities of polarized photons at a linear e^+e^-
  collider

abstract:
  The present theoretical status of spin-dependent parton densities Delta
f^{\gamma}(x,Q^2) of circularly polarized photons is briefly reviewed. It is
then demonstrated that measurements of the deep-inelastic spin asymmetry
A_1^{\gamma}\simeq g_1^{\gamma}/F_1^{\gamma} and of di-jet rapidity
distributions at a future linear e^+e^- collider appear to be particularly
suited for a determination the spin-dependent photonic quark and gluon
densities, respectively. Special emphasis is devoted to a comparison of the
different sources of polarized photons at a linear collider: the equivalent
photon approximation and backscattered laser (Compton) photons. It is shown
that backscattered laser photons are highly favorable, even indispensable, for
decent measurements of the Delta f^{\gamma}(x,Q^2).


title: Enhancement of preasymptotic effects in inclusive beauty decays

abstract:
  We extend Voloshin's recent analysis of charmed and beauty hyperon decays
based on SU(3) symmetry and heavy quark effective theory, by introducing a
rather moderate model-dependence, in order to obtain more predictive power,
e.g. the values of lifetimes of the (\Lambda_{b},\Xi_{b}) hyperon triplet and
the lifetime of \Omega_{b}. In this way we obtain an improvement of the ratio
\tau(\Lambda_{b})/\tau(B_{d}^{0}) \sim 0.9 and the hierarchy of lifetimes
\tau(\Lambda_{b}) \simeq \tau(\Xi_{b}^{0}) < \tau(\Xi_{b}^{-}) <
\tau(\Omega_{b}) with lifetimes of \Xi_{b}^{-} and \Omega_{b} exceeding the
lifetime of \Lambda_{b} by 22% and 35%, respectively.


title: Bethe-Salpeter Approach for Unitarized Chiral Perturbation Theory

abstract:
  The Bethe-Salpeter equation restores exact elastic unitarity in the $s-$
channel by summing up an infinite set of chiral loops. We use this equation to
show how a chiral expansion can be undertaken in the two particle irreducible
amplitude and the propagators accomplishing exact elastic unitarity at any
step. Renormalizability of the amplitudes can be achieved by allowing for an
infinite set of counter-terms as it is the case in ordinary Chiral Perturbation
Theory. Crossing constraints can be imposed on the parameters to a given order.
Within this framework, we calculate the leading and next-to-leading
contributions to the elastic $\pi \pi$ scattering amplitudes, for all isospin
channels, and to the vector and scalar pion form factors in several
renormalization schemes. A satisfactory description of amplitudes and form
factors is obtained. In this latter case, Watson's theorem is automatically
satisfied. From such studies we obtain a quite accurate determination of some
of the ChPT $SU(2)-$low energy parameters (${\bar l}_1 - {\bar l}_2 =
-6.1\er{0.1}{0.3} $ and ${\bar l}_6= 19.14 \pm 0.19$). We also compare the two
loop piece of our amplitudes to recent two--loop calculations.


title: Towards the Parton Densities of Polarized Photons at HERA

abstract:
  Di-jet photoproduction in polarized ep collisions at HERA is studied as a
possible tool to determine the parton content of circularly polarized photons.
The concept of the `effective parton density' approximation is extended to the
spin-dependent case.


title: Problems of the Strategy of Regions

abstract:
  Problems that arise in the application of general prescriptions of the
so-called strategy of regions for asymptotic expansions of Feynman integrals in
various limits of momenta and masses are discussed with the help of
characteristic examples of two-loop diagrams. The strategy is also reformulated
in the language of alpha parameters.


title:
NNLO evolution of deep-inelastic structure functions: the non-singlet
  case

abstract:
  We study the next-to-next-to-leading order (NNLO) evolution of flavour
non-singlet quark densities and structure functions in massless perturbative
QCD. Present information on the corresponding three-loop splitting functions is
used to derive parametrizations of these quantities, including Bjorken-x
dependent estimates of their residual uncertainties. Compact expressions are
also provided for the exactly known, but rather involved two-loop coefficient
functions. The size of the NNLO corrections and their effect on the stability
under variations of the renormalization scale are investigated. The residual
uncertainty of the three-loop splitting functions does not lead to appreciable
effects for x > 10^-2. Inclusion of the NNLO contributions reduces the main
theoretical uncertainty of alpha_s determinations from non-singlet scaling
violations by more than a factor of two.


title:
Precise measurement of $\Gamma (H \longrightarrow \gamma \gamma)$ at a
  PLC and theoretical consequences

abstract:
  With the LEP II Higgs search approaching exclusion limits on low values of
$\tan \beta \sim 2$ it becomes increasingly important to investigate physical
quantities sensitive to large masses of a pseudoscalar Higgs mass. This regime
is difficult and over a large range of $\tan \beta$ impossible to cover at the
LHC proton proton collider. In this paper we focus on the achievable
statistical precision of the Higgs decay into two photons at a future $\gamma
\gamma$ collider (PLC) in the MSSM mass range below 130 GeV. The MSSM and SM
predictions for $\Gamma (H \longrightarrow \gamma \gamma)$ can differ by up to
10 % even in the decoupling limit of large $m_A$. We summarize recent progress
in both the theoretical understanding of the background process $\gamma \gamma
\longrightarrow q \bar{q}$, $q=\{b,c\}$, and in the expected detector
performance allow for a high accuracy of the lightest MSSM or SM Higgs boson
decay into a $b \bar{b}$ pair. We find that for optimized but still realistic
detector and accelerator assumptions, statistically a 1.4% accuracy is feasible
after about four years of collecting data for a Higgs boson mass which excludes
$\tan \beta <2$.


title:
CP Phases in Correlated Production and Decay of Neutralinos in the
  Minimal Supersymmetric Standard Model

abstract:
  We investigate the associated production of neutralinos
$e^+e^-\to\tilde{\chi}^0_1\tilde{\chi}^0_2$ accompanied by the neutralino
leptonic decay $\tilde{\chi}^0_2\to\tilde{\chi}^0_1 \ell^+\ell^-$, taking into
account initial beam polarization and production-decay spin correlations in the
minimal supersymmetric standard model with general CP phases but without
generational mixing in the slepton sector. The stringent constraints from the
electron EDM on the CP phases are also included in the discussion. Initial beam
polarizations lead to three CP--even distributions and one CP--odd
distribution, which can be studied independently of the details of the
neutralino decays. We find that the production cross section and the branching
fractions of the leptonic neutralino decays are very sensitive to the CP
phases. In addition, the production--decay spin correlations lead to several
CP--even observables such as lepton invariant mass distribution, and lepton
angular distribution, and one interesting T--odd (CP--odd) triple product of
the initial electron momentum and two final lepton momenta, the size of which
might be large enough to be measured at the high--luminosity future
electron--positron collider or can play a complementary role in constraining
the CP phases with the EDM constraints.


title:
Two-hadron interference fragmentation functions. Part I: general
  framework

abstract:
  We investigate the properties of interference fragmentation functions
measurable from the distribution of two hadrons produced in the same jet in the
current fragmentation region of a hard process. We discuss the azimuthal
angular dependences in the leading order cross section of two-hadron inclusive
lepton-nucleon scattering as an example how these interference fragmentation
functions can be addressed separately.


title: Higgs Mass Textures in Flipped SU(5)

abstract:
  We analyze the Higgs doublet-triplet mass splitting problem in the version of
flipped SU(5) derived from string theory. Analyzing non-renormalizable terms up
to tenth order in the superpotential, we identify a pattern of field vev's that
keeps one pair of electroweak Higgs doublets light, while all other Higgs
doublets and all Higgs triplets are kept heavy, with the aid of the economical
missing-doublet mechanism found in the field-theoretical version of flipped
SU(5). The solution predicts that second-generation charge -1/3 quarks and
charged leptons are much lighter than those in the third generation.


title: Dynamically broken Topcolor at Large-N

abstract:
  We analyze a model of dynamically broken topcolor in the limit in which the
number of colors is large. We show that the second order nature of the phase
transition, necessary for the success of topcolor models, passes the nontrivial
check of consistency with the large N limit. We also identify and discuss a
class of theories that generalizes the topcolor phenomenon to a theory with a
richer structure of fermions and global symmetries.


title: Constraints on Exotic Mixing of Three Neutrinos

abstract:
  Exotic explanations are considered for atmospheric neutrino observations. Our
analysis includes matter effects and the mixing of all three neutrinos under
the simplifying assumption of only one relevant mixing scale. Constraints from
accelerator, reactor and solar neutrinos are included. We find that the
proposed mixing mechanisms based on violations of Lorentz invariance or on
violations of the equivalence principle cannot explain the recent observations
of atmospheric neutrino mixing. However the data still allow a wide range of
energy dependences for the vacuum mixing scale, and also allow large
electron-neutrino mixing of atmospheric neutrinos. Next generation long
baseline experiments will constrain these possibilities.


title: LAB observables for the muon polarization in K^+ --> \pi^+ \mu^+ \mu^-

abstract:
  We analyse the muon longitudinal polarization asymmetry \Delta_long in the
decay K^+ --> \pi^+ \mu^+ mu^-. It is stressed that, since the muon helicities
are not Lorentz-invariant quantities, the magnitude of \Delta_long depends in
general on the reference frame. We consider the muon helicities in the LAB
system, and study the sensitivity of the longitudinal polarization asymmetry to
the flavour-mixing parameters in the Standard Model for stopped and in-flight
decaying K^+. A similar analysis is carried out for the decay K_L --> \mu^+
\mu^-. We find that in both cases the asymmetry is diluted when increasing the
energy of the decaying kaons.


title: The Standard Model and the Generalized Covariant Derivative

abstract:
  The generalized covariant derivative, that uses both scalar and vector
bosons, is defined. It is shown how a grand unified theory of the Standard
Model can be constructed using a generalized Yang-Mills theory.


title: A Supersymmetric Model with an Extra U(1) Gauge Symmetry

abstract:
  In the standard model the proton is protected from decay naturally by gauge
symmetries, whereas in the ordinary minimal supersymmetric standard model an ad
hoc discrete symmetry is imposed for the proton stability. We present a new
supersymmetric model in which the proton decay is forbidden by an extra U(1)
gauge symmetry. Particle contents are necessarily increased to be free from
anomalies, incorporating right-handed neutrinos. Both Dirac and Majorana masses
are generated for neutrinos, yielding non-vanishing but small masses. The
superpotential consists only of trilinear couplings and the mass parameter
$\mu$ of the minimal model is induced by spontaneous breaking of the U(1)
symmetry.


title:
Yukawa Corrections to Charged Higgs Boson Production in Association with
  a Top Quark at Hadron Colliders

abstract:
  We calculate the Yukawa corrections of order
$O(\alpha_{ew}m_{t(b)}^{2}/m_{W}^{2})$ to charged Higgs boson production in
association with a top quark at the Tevatron and the LHC. The corrections are
not very sensitive to the mass of the charged Higgs boson and can exceed -20%
for low values of $\tan\beta$, where the contribution of the top quark is
large, and high values of $\tan\beta$ where the contribution of the bottom
quark becomes large. These Yukawa corrections could be significant for charged
Higgs boson discovery searches based on this production process, particularly
at the LHC where the cross section is relatively large.


title: Bound states in quantum field theory, scalar fields

abstract:
  The main aim of this paper is to demonstrate the method called "the
Bosonization of Nonlocal Currents" (BNC), used for calculations of bound states
in a quark model, within the simplest relativistic quantum field model of two
scalar fields with the Yukawa type interaction. A second aim is to clarify the
relation between BNC and two widely used methods, employed in recent particle
physics to calculate bound states of interacting particles, based on the
nonrelativistic Schrodinger equation (the S-method), and the relativistic
Bethe-Salpeter equation (the BS-method), and to determine the conditions on
parameters of a quantum field model dictating a definite method to be applied.
  It is shown that all these methods can be applied only in the weak coupling
regime when the effective dimensionless coupling constant should be less than
1. The basic parameter separating the relativistic and nonrelativistic pictures
is the ratio of the masses of the exchange ("meson") and constituent
("nucleon") particles. If this ratio and the coupling constant are small then
the potential picture takes place, i.e., the bound state is described by the
nonrelativistic Schrodinger equation. Otherwise, the Bethe-Salpeter equation or
the BNC should be employed. One notes that the BNC method has a slightly wider
region of applicability in this case.


title:
Model Investigation of Non-Thermal Phase Transition in High Energy
  Collisions

abstract:
  The Non-thermal phase transition in high energy collisions is studied in some
detail in the framework of random cascade model. The relation between the
characteristic parameter $\lambda_q$ of phase transition and the rank $q$ of
moment is obtained using Monte Carlo simulation, and the existence of two
phases in self-similarly cascading multiparticle systems is shown. The relation
between the critical point $q_c$ of phase transition on the fluctuation
parameter $\alpha$ is obtained and compared with the experimental results from
NA22. The same study is carried out also by analytical calculation under
central limit approximation. The range of validity of the central limit
approximation is discussed.


title: Four-neutrino mixing

abstract:
  It is shown that only two four-neutrino schemes are compatible with the
results of all neutrino oscillation experiments. These two schemes have a mass
spectrum composed of two pairs of neutrinos with close masses separated by the
"LSND gap" of the order of 1 eV.


title: Masses and Internal Structure of Mesons in the String Quark Model

abstract:
  The relativistic quantum string quark model, proposed earlier, is applied to
all mesons, from pion to $\Upsilon$, lying on the leading Regge trajectories
(i.e., to the lowest radial excitations in terms of the potential quark
models). The model describes the meson mass spectrum, and comparison with
measured meson masses allows one to determine the parameters of the model:
current quark masses, universal string tension, and phenomenological constants
describing nonstring short-range interaction. The meson Regge trajectories are
in general nonlinear; practically linear are only trajectories for light-quark
mesons with non-zero lowest spins. The model predicts masses of many new
higher-spin mesons. A new $K^*(1^-)$ meson is predicted with mass 1910 Mev. In
some cases the masses of new low-spin mesons are predicted by extrapolation of
the phenomenological short-range parameters in the quark masses. In this way
the model predicts the mass of $\eta_b(1S)(0^{-+})$ to be $9500\pm 30$ MeV, and
the mass of $B_c(0^-)$ to be $6400\pm 30$ MeV (the potential model predictions
are 100 Mev lower). The relativistic wave functions of the composite mesons
allow one to calculate the energy and spin structure of mesons. The average
quark-spin projections in polarized $\rho$-meson are twice as small as the
nonrelativistic quark model predictions. The spin structure of $K^*$ reveals an
80% violation of the flavour SU(3). These results may be relevant to
understanding the ``spin crises'' for nucleons.


title:
High Order Perturbative QCD Approach to Multiplicity Distributions of
  Quark and Gluon Jets

abstract:
  The second and third factorial moments of the multiplicity distributions of
gluon and quark jets are calculated up to the next-to-next-to-next-to leading
order in perturbative QCD, using the equations for generating functions. The
results are confronted with experimental data. A general discussion on high
order corrections revealed by such an approach is given. Other possible
corrections and approaches are discussed as well.


title:
Two-hadron interference fragmentation functions. Part II: a model
  calculation

abstract:
  We present a model calculation of leading order interference fragmentation
functions arising from the distribution of two hadrons produced in the same jet
of a fragmenting quark in a hard process. Using a simple spectator model for
the mechanism of the hadronization process, for the first time we give a
complete calculation and numerical estimates for the example of a proton-pion
pair production with its invariant mass on the Roper resonance.


title: Ultrasoft Effects in Heavy-Quarkonium Physics

abstract:
  In the framework of nonrelativistic QCD, we consider a new class of radiative
corrections, which are generated at next-to-next-to-next-to-leading order
through the chromoelectric dipole interaction of heavy quarkonium with
ultrasoft virtual gluons. We provide analytical formulae from which the
resulting shifts in the quarkonium energy levels and the wave functions at the
origin may be calculated. We discuss the phenomenological implications for the
top-antitop and Upsilon systems and point out some limitations of describing
charmonium using a Coulomb potential.


title: Time Ordering, Energy Ordering, and Factorization

abstract:
  Relations between integrals of time-ordered product of operators, and their
representation in terms of energy-ordered products are studied. Both can be
decomposed into irreducible factors and these relations are discussed as well.
The energy-ordered representation was invented to separate various infrared
contributions in gauge theories. It is shown that the irreducible time-ordered
expressions can be used to accomplish the same purpose. Besides, it has the
added advantage of being factorizable.


title: Quark structure of pseudoscalar mesons

abstract:
  I review to which extent the properties of pseudoscalar mesons can be
understood in terms of the underlying quark (and eventually gluon) structure.
Special emphasis is put on the progress in our understanding of eta-eta'
mixing. Process-independent mixing parameters are defined, and relations
between different bases and conventions are studied. Both, the low-energy
description in the framework of Chiral Perturbation Theory and the high-energy
application in terms of light-cone wave functions for partonic Fock states, are
considered. A thorough discussion of theoretical and phenomenological
consequences of the mixing approach will be given. Finally, I will discuss
mixing with other states pi^0, eta(c), ...).


title: The Casimir energy of skyrmions in the 2+1-dimensional O(3)-model

abstract:
  One-loop quantum corrections to the classical vortices in 2+1 dimensional
O(3)-models are evaluated. Skyrme and Zeeman potential terms are used to
stabilize the size of topological solitons. Contributions from zero modes,
bound-states and scattering phase-shifts are calculated for vortices with
winding index n=1 and n=2. For both cases the S-matrix shows a pronounced
series of resonances for magnon-vortex scattering in analogy to the
well-established baryon resonances in hadron physics, while vortices with n>2
are already classically unstable against decay. The quantum corrections
destabilize the classically bound n=2 configuration. Approximate independence
of the results with respect to changes in the renormalization scale is
demonstrated.


title:
Plasma influence on the neutrino - electron processes in a strong
  magnetic field

abstract:
  An influence of the magnetized electron - positron plasma on the absorption
and loss of the energy and momentum in a process of neutrino propagation is
investigated. A total contribution of all crossed processes, $\nu \to \nu e^-
e^+$, $\nu e^- \to \nu e^-$, $\nu e^+ \to \nu e^+$, $\nu e^- e^+ \to \nu$, is
found for the first time, which appears not to depend on the chemical potential
of electron-positron gas. Relatively simple expressions for the probability and
mean losses of the neutrino energy and momentum are obtained, which are
suitable for a quantitative analysis.


title: Scalar One-Loop Integrals using the Negative-Dimension Approach

abstract:
  We study massive one-loop integrals by analytically continuing the Feynman
integral to negative dimensions as advocated by Halliday and Ricotta and
developed by Suzuki and Schmidt. We consider n-point one-loop integrals with
arbitrary powers of propagators in general dimension D. For integrals with m
mass scales and q external momentum scales, we construct a template solution
valid for all n which allows us to obtain a representation of the graph in
terms of a finite sum of generalised hypergeometric functions with m+q-1
variables. All solutions for all possible kinematic regions are given
simultaneously, allowing the investigation of different ranges of variation of
mass and momentum scales.
  As a first step, we develop the general framework and apply it to massive
bubble and vertex integrals. Of course many of these integrals are well known
and we show that the known results are recovered. To give a concrete new
result, we present expressions for the general vertex integral with one
off-shell leg and two internal masses in terms of hypergeometric functions of
two variables that converge in the appropriate kinematic regions. The kinematic
singularity structure of this graph is sufficiently complex to give insight
into how the negative-dimension method operates and gives some hope that more
complicated graphs can also be evaluated.


title: Pion Form Factor in QCD at Intermediate Momentum Transfers

abstract:
  We present a quantitative analysis of the electromagnetic pion form factor in
the light-cone sum rule approach, including radiative corrections and
higher-twist effects. The comparison to the existing data favors the asymptotic
profile of the pion distribution amplitude and allows to estimate the
deviation: $(\int du/u \phi_\pi(u))/ (\int du/u \phi^{\rm as}_\pi(u))=$
1.1$\pm$ 0.1 at the scale 1 GeV. Special attention is payed to the precise
definition and interplay of soft and hard contributions at intermediate
momentum transfer, and to matching of the sum rule to the perturbative QCD
prediction. We observe a strong numerical cancellation between the soft (end
point) contribution and power suppressed hard contributions of higher twist, so
that the total nonperturbative correction to the usual pQCD result turns out to
be of order 30% for $Q^2\sim 1$ GeV$^2$.


title: Decays of the MSSM Higgs Bosons with Explicit CP Violation

abstract:
  We study Higgs boson decays in the minimal supersymmetric standard model
where the tree-level CP invariance of the Higgs potential is explicitly broken
by loop effects of soft CP-violating Yukawa interactions related to scalar
quarks of the third generation. The scalar-pseudoscalar mixing among two
neutral CP-even Higgs bosons and one CP-odd Higgs boson due to explicit CP
violation modifies their tree-level couplings to fermions, to the W^\pm and Z
bosons and to Higgs bosons themselves significantly. We analyze the
phenomenological impact of explicit CP violation on the branching ratios of the
neutral Higgs boson decays in detail and discuss how to directly confirm the
existence of explicit CP violation through \tau^+ \tau^- and t \bar{t} spin
correlations in the decays of the neutral Higgs bosons into a tau-lepton pair
and a top-quark pair.


title:
New extraction of color-octet NRQCD matrix elements from charmonium
  hadroproduction

abstract:
  We re-analyze Tavatron data on charmonium hadroproduction in the framework of
the color-octet model implemented in the event generator PYTHIA taking into
account initial-state radiation of gluons and Altarelli-Parisi evolution of
final-state gluons fragmenting into $c\bar{c}$ pairs. We obtain new values for
the color-octet matrix elements relevant to this production process. We discuss
the sensitivity of our results to the transverse momentum lower cut-off
employed in the generation to avoid the problematic $p_t{\to}0$ region, arguing
about the reliability of our previous extraction of the NRQCD matrix elements
for the $^3S_1^{(8)}$ and $^1S_0^{(8)}+^3P_J^{(8)}$ contributions. Finally we
extrapolate to LHC energies to get predictions on the $J/\psi$ direct
production rate.


title:
Transversity Distribution Does Not Contribute to Hard Exclusive
  Electroproduction of Mesons

abstract:
  We show that in hard exclusive electroproduction, ep-->eVp, the leading-twist
hard-scattering coefficient for the production of a transversely polarized
vector meson V vanishes to all orders of perturbation theory. This implies that
this process cannot be used to measure the skewed transversity distribution of
quarks in a hadron. In contrast, a recent calculation obtained a non-zero value
at NLO. We show that this calculation is incorrect because it failed to include
the necessary collinear subtractions. Our method of proof also applies to other
processes whose hard-scattering coefficients are constrained by chirality and
helicity conservation, and thus validates helicity selection rules based on
these symmetries.


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

abstract:
  The simplest unified extension of the Minimal Supersymmetric Standard Model
with bi-linear R--Parity violation provides a predictive scheme for neutrino
masses which can account for the observed atmospheric and solar neutrino
anomalies in terms of bi-maximal neutrino mixing. The maximality of the
atmospheric mixing angle arises dynamically, by minimizing the scalar
potential, while the solar neutrino problem can be accounted for either by
large or by small mixing oscillations. One neutrino picks up mass by mixing
with neutralinos, while the degeneracy and masslessness of the other two is
lifted only by loop corrections. Despite the smallness of neutrino masses
R-parity violation is observable at present and future high-energy colliders,
providing an unambiguous cross-check of the model.


title: Higher order pair corrections to electron-positron annihilation

abstract:
  Radiative corrections due to pair production in process of electron-positron
annihilation are considered. The main attention is paid to the corrections of
the third order. Simultaneous emission of photons and pairs is taken into
account. The leading log approximation and convolution procedure are used.
Exponentiation is discussed. Theoretical uncertainty in description of higher
order secondary pairs is estimated.


title: Matching of the Shape Function

abstract:
  The shape function f(k_+) describes Fermi motion effects in inclusive
semi-leptonic decays such as B -> X_u+e+nu near the end-point of the lepton
spectrum. We compute the leading one-loop corrections to the shape function
f(k_+) in the effective theory with a hard cut-off regularization. The matching
constant onto full QCD is infrared safe, i.e. the leading infrared singularity
represented by the term log^2(k_+) cancels in the difference of integrals. We
compare the hard cut-off result with the result in dimensional regularization,
the latter containing an additional factor of two in the coefficient of the
log^2(k_+) term, and consequently requiring an oversubtraction.


title: Low-Mass Dileptons at the CERN-SpS: Evidence for Chiral Restoration?

abstract:
  Using a rather complete description of the in-medium $\rho$ spectral function
- being constrained by various independent experimental information - we
calculate pertinent dilepton production rates from hot and dense hadronic
matter. The strong broadening of the $\rho$ resonance entails a reminiscence to
perturbative $q\bar q$ annihilation rates in the vicinity of the phase
boundary. The application to dilepton observables in Pb(158AGeV)+Au collisions
- incorporating recent information on the hadro-chemical composition at
CERN-SpS energies - essentially supports the broadening scenario. Possible
implications for the nature of chiral symmetry restoration are outlined.


title:
Nearly Mass-Degenerate Majorana Neutrinos: Double Beta Decay and
  Neutrino Oscillations

abstract:
  Assuming equal tree-level Majorana masses for the standard-model neutrinos,
either from the canonical seesaw mechanism or from a heavy scalar triplet, I
discuss how their radiative splitting may be relevant to neutrinoless double
beta decay and neutrino oscillations.


title: Angular dependences in electroweak semi-inclusive leptoproduction

abstract:
  We present the leading order unpolarized and polarized cross sections in
electroweak semi-inclusive deep inelastic leptoproduction. The azimuthal
dependences in the cross section differential in the transverse momentum of the
vector boson arise due to intrinsic transverse momenta of the quarks. However,
the presented asymmetries are not suppressed by inverse powers of the hard
scale. We discuss the different opportunities to measure specific asymmetries
as offered by neutral compared to charged current processes and point out the
optimal kinematical regions. The present and (proposed) future HERA collider
experiments would be most suitable for measuring some of the asymmetries
discussed here, especially in case of Lambda production.


title:
New backgrounds in Trilepton, Dilepton and Dilepton plus Tau Jet SUSY
  Signals at the Tevatron

abstract:
  We determine the Tevatron's reach in supersymmetric parameter space in
trilepton, like-sign dilepton, and dilepton plus tau-jet channels, taking all
relevant backgrounds into account. We show results for the minimal supergravity
model. With a standard set of cuts we find that the previously unaccounted for
$W\gamma^\ast$ background is larger than all other backgrounds combined. We
include cuts on the dilepton invariant mass and the $W$-boson transverse mass
to reduce the $W\gamma^\ast$ background to a reasonable level. We optimize cuts
at each point in supersymmetry parameter space in order to maximize
signal-to-noise.


title:
Scaling Property of the global string in the radiation dominated
  universe

abstract:
  We investigate the evolution of the global string network in the radiation
dominated universe by use of numerical simulations in 3+1 dimensions. We find
that the global string network settles down to the scaling regime where the
energy density of global strings, $\rho_{s}$, is given by $\rho_{s} = \xi \mu /
t^2$ with $\mu$ the string tension per unit length and the scaling parameter,
$\xi \sim (0.9-1.3)$, irrespective of the cosmic time. We also find that the
loop distribution function can be fitted with that predicted by the so-called
one scale model. Concretely, the number density, $n_{l}(t)$, of the loop with
the length, $l$, is given by $n_{l}(t) = \nu/[t^{3/2} (l + \kappa t)^{5/2}]$
where $\nu \sim 0.0865$ and $\kappa$ is related with the Nambu-Goldstone(NG)
boson radiation power from global strings, $P$, as $P = \kappa \mu$ with
$\kappa \sim 0.535$. Therefore, the loop production function also scales and
the typical scale of produced loops is nearly the horizon distance. Thus, the
evolution of the global string network in the radiation dominated universe can
be well described by the one scale model in contrast with that of the local
string network.


title: Charm Hadroproduction in $k_T$-Factorization Approach

abstract:
  We compare the theoretical status and the numerical predictions of two
approaches for heavy quark production in the high energy hadron collisions,
namely the conventional LO parton model with collinear approximation and
$k_T$-factorization approach. The main assumptions used in the calculations are
discussed. To extract the differences coming from the matrix elements we use
very simple gluon structure function and fixed coupling. It is shown that the
$k_T$-factorization approach calculated formally in LO and with Sudakov form
factor accounts for many contributions related usually to NLO (and even NNLO)
processes of the conventional parton model


title: Neutral Kaon System in Dense Matter and Heavy-Ion Collisions

abstract:
  Above a critical matter density the propagating modes of the neutral kaon
system are essentially eigenstates of strangeness, but below it they are almost
complete eigenstates of CP. We estimate the real and imaginary parts of the
energies of these modes and their mixing at all densities up to nuclear matter
density $2\times 10^{14}$ g/cm$^3$. In a heavy ion collision the strong
interactions create eigenstates of strangeness, and these propagate
adiabatically until the density has fallen to the critical value, whereupon the
system undergoes a sudden transition to (near) eigenstates of CP. We estimate
the critical density to be 20 g/cm$^3$, and that this density will be reached
about $2\times 10^5$ fm/c after the end of the collision.


title: Short Distance Mass of a Heavy Quark at Order \alpha_s^3

abstract:
  The relation between the on-shell quark mass and the mass defined in the
modified minimal subtraction scheme is computed up to order \alpha_s^3.
Implications for the numerical values of the top and bottom quark masses are
discussed. We show that the new three-loop correction significantly reduces the
theoretical uncertainty in the determination of the quark masses.


title: Non-Thermal Production of Dangerous Relics in the Early Universe

abstract:
  Many models of supersymmetry breaking, in the context of either supergravity
or superstring theories, predict the presence of particles with weak scale
masses and Planck-suppressed couplings. Typical examples are the scalar moduli
and the gravitino. Excessive production of such particles in the early Universe
destroys the successful predictions of nucleosynthesis. In particular, the
thermal production of these relics after inflation leads to a bound on the
reheating temperature, T_{RH} < 10^9 GeV. In this paper we show that the
non-thermal generation of these dangerous relics may be much more efficient
than the thermal production after inflation. Scalar moduli fields may be
copiously created by the classical gravitational effects on the vacuum state.
Consequently, the new upper bound on the reheating temperature is shown to be,
in some cases, as low as 100 GeV. We also study the non-thermal production of
gravitinos in the early Universe, which can be extremely efficient and overcome
the thermal production by several orders of magnitude, in realistic
supersymmetric inflationary models.


title:
Photon Fragmentation in Large-Q2 ep Collisions at Next-to-Leading Order
  QCD

abstract:
  We study the production of photons accompanied by jets in large-Q2 deep
inelastic scattering. Numerical results for the cross section differential with
respect to the fraction of momentum z_gamma carried by a photon inside a jet at
large z_gamma, up to O(alpha alpha_s) in perturbative QCD, are presented. The
sensitivity to the fragmentation contribution allows one to study the
quark-to-photon fragmentation function. Our results can be confronted with
future experimental data from HERA.


title: A new global analysis of deep inelastic scattering data

abstract:
  A new QCD analysis of Deep Inelastic Scattering (DIS) data is presented. All
available neutrino and anti-neutrino cross sections are reanalysed and included
in the fit, along with charged-lepton DIS and Drell-Yan data. A massive
factorisation scheme is used to describe the charm component of the structure
functions. Next-to-leading order parton distribution functions are provided. In
particular, the strange sea density is determined with a higher accuracy with
respect to other global fits.


title: Factorization for Hard Exclusive Electroproduction

abstract:
  This talk summarized the proof of hard-scattering factorization for hard
exclusive electroproduction processes: deeply virtual Compton scattering and
exclusive meson production.


title:
I : Chiral Perturbation for Kaons II: The $\Delta I=1/2$-rule in the
  Chiral Limit

abstract:
  I : Chiral Perturbation Theory is introduced and its applications to
semileptonic and nonleptonic kaon decays are discussed.
  II: The method of large $N_c$ is used to calculate $K\to\pi\pi$ nonleptonic
matrix elements, in particular the matching procedure between long and
short-distance evolution that takes all scheme dependence correctly into
account is discussed. Numerical results reproduce the $\Delta I=1/2$ rule
without the introduction of any free parameters.


title: The quark loop calculation of the gamma -> 3 pi form factor

abstract:
  The presently experimentally interesting form factor for the anomalous
process gamma -> pi^+ pi^0 pi^- is calculated as the quark "box"-amplitude
where the intermediate fermion loop is the one of constituent quarks with the
pseudoscalar coupling to pions. This also corresponds to the form factor, in
the lowest order in pion interactions, of the sigma-model and of the chiral
quark model. We give the analytic expression for the form factor in terms of an
expansion in the pion momenta up to the order O(p^8) relative to the soft point
result, and also perform its exact numerical evaluation. We compare our
predictions with those of the vector meson dominance and chiral perturbation
theory, as well as with the scarce data available so far.


title: Mechanism for a next-to-lowest lying scalar meson nonet

abstract:
  Recent work suggests the existence of a non-conventional lowest-lying scalar
nonet containing the a0(980). Then the a0(1450) and also the K0*(1430) are
likely candidates to belong to a conventional p-wave $q \bar q$ nonet. However
a comparison of their properties with those expected on this basis reveals a
number of puzzling features. It is pointed out that these puzzles can be
resolved in a natural and robust way by assuming a ``bare'' conventional p-wave
scalar $q \bar q$ nonet to mix with a lighter four quark $qq \bar q \bar q$
scalar nonet to form new ``physical'' states. The essential mechanism is driven
by the fact that the isospinor is lighter than the isovector in the unmixed $qq
\bar q \bar q$ multiplet.


title:
Nonperturbative corrections to B -> X_s l^+ l^- with phase space
  restrictions

abstract:
  We study nonperturbative corrections up to O(1/m_b^3) in the inclusive rare B
decay B -> X_s l^+ l^- by performing an operator product expansion. The values
of the matrix elements entering at this order are unknown and introduce
uncertainties into physical quantities. Imposing a phase space cut to eliminate
the $c \bar{c}$ resonances we find that the O(1/m_b^3) corrections introduce an
O(10%) uncertainty in the measured rate. We also find that the contributions
arising at O(1/m_b^3) are comparable to the ones arising at O(1/m_b^2) over the
entire region of phase space.


title: Measurements of Masses in SUGRA Models at LHC

abstract:
  This paper presents new measurements in a case study of the minimal SUGRA
model with m_0=100 GeV, mhalf=300 GeV, A_0=0, tan(beta)=2.1, and mu=+1 based on
four-body distributions from three-step decays and on minimum masses in such
decays. These measurements allow masses of supersymmetric particles to be
determined without relying on a model. The feasibility of testing slepton
universality at the ~0.1% level at high luminosity is discussed. In addition,
the effect of enlarging the parameter space of the minimal SUGRA model is
discussed. The direct production of left handed sleptons and the
non-observation of additional structure in the dilepton invariant mass
distributions is shown to provide additional constraints.


title: Measurements in SUGRA Models with Large tan beta at LHC

abstract:
  We present an example of a scenario of particle production and decay in
supersymmetry models in which the supersymmetry breaking is transmitted to the
observable world via gravitational interactions. The case is chosen so that
there is a large production of tau leptons in the final state. It is
characteristic of large tan beta in that decays into muons and electrons may be
suppressed. It is shown that hadronic tau decays can be used to reconstruct
final states.


title: Neutrino Masses and Oscillations in Models with Large Extra Dimensions

abstract:
  We discuss the profile of neutrino masses and mixings in models with large
extra dimensions when right handed neutrinos are present in the branes along
with the usual standard model particles. In these models, string scale must be
bigger than $10^{8}$ GeV to have desired properties for the neutrinos at low
energies. The lightest neutrino mass is zero and there is oscillations to
sterile neutrinos that are different from other models with the bulk neutrino.


title: Classification and Application of Triangular Quark Mass Matrices

abstract:
  The hierarchical structure in the quark masses and mixings allows its ten
physical parameters to be most conveniently encoded in mass matrices of the
upper triangular form. We classify these matrices in the hierarchical, minimal
parameter basis where the mismatch between the weak and mass eigenstates
involves only small mixing angles. Ten such pairs are obtained for the up and
down quarks. This analysis can be used to classify texture zeros of general
mass matrices. For hermitian mass matrices with five texture zeros, this method
yields immediately five pairs of textures with simple, analytic predictions for
the quark mixings. Comparison with data indicates that, of the five pairs,
three are disfavored, one is marginally acceptable, while the fifth fits well.


title:
Cumulative Non-Decoupling Effects of Kaluza-Klein Neutrinos in
  Electroweak Processes

abstract:
  In Kaluza-Klein theories of low-scale quantum gravity, gravitons and
isosinglet neutrinos may propagate in a higher-dimensional space with large
compact dimensions, whereas all particles of the Standard Model are confined on
a (1+3)-dimensional subspace. After compactification of the extra dimensions,
the resulting Yukawa couplings of the Kaluza-Klein neutrinos to the lepton
doublets become naturally very suppressed by a higher-dimensional volume
factor, in agreement with phenomenological observations. We show that one-loop
effects induced by Kaluza-Klein neutrinos, albeit tiny individually, act
cumulatively in electroweak processes, giving rise to a non-decoupling
behaviour for large values of the higher-dimensional Yukawa couplings. Owing to
the non-decoupling effects of Kaluza-Klein neutrinos, we can derive stronger
constraints on the parameters of the theory that originate from the
non-observation of flavour-violating and universality-breaking phenomena, which
involve the W and Z bosons, and the e, $\mu$ and $\tau$ leptons.


title:
Application of the negative-dimension approach to massless scalar box
  integrals

abstract:
  We study massless one-loop box integrals by treating the number of space-time
dimensions D as a negative integer. We consider integrals with up to three
kinematic scales (s, t and either zero or one off-shell legs) and with
arbitrary powers of propagators. For box integrals with q kinematic scales
(where q=2 or 3) we immediately obtain a representation of the graph in terms
of a finite sum of generalised hypergeometric functions with q-1 variables,
valid for general D. Because the power each propagator is raised to is treated
as a parameter, these general expressions are useful in evaluating certain
types of two-loop box integrals which are one-loop insertions to one-loop box
graphs. We present general expressions for this particular class of two-loop
graphs with one off-shell leg, and give explicit representations in terms of
polylogarithms in the on-shell case.


title:
Atomic Parity Violation and Precision Electroweak Physics - An Updated
  Analysis

abstract:
  A new analysis of parity violation in atomic cesium has led to the improved
value of the weak charge, $Q_W({\rm Cs}) = -72.06 \pm 0.46$. The implications
of this result for constraining the Peskin-Takeuchi parameters S and T and for
guiding searches for new Z bosons are discussed.


title: About some Distinguishing Features of the Weak Interaction

abstract:
  In this work it is shown that, in contrast to the strong and electromagnetic
theories, additive conserved numbers (such as lepton, aromatic and another
numbers) and gamma-5 anomaly do not appear in the standard weak interaction
theory. It means that in this interaction the additive numbers cannot be
conserved. These results are the consequence of specific character of the weak
interaction: the right components of spinors do not participate in this
interaction. The schemes of violation of the aromatic and lepton numbers were
considered.


title:
An effective relaxation-time approach to collisionless quark-gluon
  plasma

abstract:
  We present an effective relaxation-time theory to study the collisionless
quark-gluon plasma. Applying this method we calculate the damping rate to be of
order $g^2T$ and find plasmon scattering is the damping mechanism. The damping
for the transverse mode is stronger than the longitudinal one.


title:
Non-Abelian Collective Excitations in Unlinearized Quark-Gluon Plasma
  Media

abstract:
  We study the effect of unlinearized medium on the collective excitations in
quark-gluon plasma. We present two kinds of non-Abelian oscillation solutions
which respectively correspond to weakly and strongly nonlinear coupling of
field components in color space. We also show that the weakly nonlinear
solution is similar to Abelian-like one but has the frequency shift, which is
of order $g^2T$, from eigenfrequency.


title:
Model-dependent Axion as Quintessence with Almost Massless Hidden Sector
  Quarks

abstract:
  A pseudo-Goldstone boson for {\it quintessence} is known to require the decay
constant $F_q\sim M_P$ and the height of the potential $(0.003 {\rm eV})^4$,
and hence the pseudo-Goldstone boson mass of order $10^{-33}$ eV. The
model-dependent axion in some superstring models is suggested as a good
candidate for the quintessence. We realize this idea with a hidden-sector gauge
group $SU(3)_H\times U(1)_H$. The hidden-sector instanton contribution to the
quintessence potential is suppressed by the almost massless hidden-sector
quarks. The model-independent axion is the QCD axion required for the strong CP
solution.


title:
Quasiclassical Green function in an external field and small-angle
  scattering

abstract:
  The quasiclassical Green functions of the Dirac and Klein-Gordon equations in
the external electric field are obtained with the first correction taken into
account. The relevant potential is assumed to be localized, while its spherical
symmetry is not required. Using these Green functions, the corresponding wave
functions are found in the approximation similar to the Furry-Sommerfeld-Maue
approximation. It is shown that the quasiclassical Green function does not
coincide with the Green function obtained in the eikonal approximation and has
a wider region of applicability. It is illustrated by the calculation of the
small-angle scattering amplitude for a charged particle and the forward photon
scattering amplitude. For charged particles, the first correction to the
scattering amplitude in the non-spherically symmetric potential is found. This
correction is proportional to the scattering angle. The real part of the
amplitude of forward photon scattering in a screened Coulomb potential is
obtained.


title: Supersymmetry and Future Colliders

abstract:
  In this talk, I review precision SUSY study at LHC and TeV scale e+e- linear
colliders (LC). We discuss the study of the 3 body decay of the second lightest
neutralino \chi^0_2--> \chi^0_1 ll or the 2 body decay \chi^0_2-->\tilde{l}l at
LHC. In the former case, the whole m_{ll} distribution observed at LHC would
constrain ino mixing and slepton masses. On the other hand, when \tilde{l}l
decay is open, the distribution of the asymmetry of the transverse momentum of
lepton pair A_T= p_{T1}/p_{T2} peaks at A_E=p_{1}/p_{2} in \chi^0_2 rest frame
for m_{ll} << m^{max}_{ll} samples, providing another model independent
information. The peak position and the edge of the m_{ll} distribution
constrain m_{\chi^0_2}, m_{\chi}^0_1} and m_{\tilde{l}}. Slepton mass
universality may be checked within a few % in the early stage of the
experiment. Finally I discuss the physics at TeVscale LC. The mass and
couplings of sparticles will be measured withinO(1%) error, and measurement of
the radiative correction to the ino-slepton-lepton coupling will determine the
first generation squark mass scale even in decoupling scenarios.


title: Preons, Dark Matter and the Production of Early Cosmological Structures

abstract:
  If the preon structure of quarks, leptons and gauge bosons will be proved
then in the Universe during relativistic phase transition the production of
nonperturbative preon condensates has been occured collective excitations of
which are perceived as pseudogoldstone bosons. Dark matter consisting of
pseudogoldstone bosons of familon type contains a "hot" component from massless
particles and a "cold" (nonrelativistic) component from massive particles. It
is shown that such dark matter was undergone to two relativistic phase
transitions temperatures of which were different. In the result of these phase
transitions the structurization of dark matter and therefore the baryon
subsystem has taken place. Besides, the role of particle generations in the
Universe become more evident. For the possibility of structurization of matter
as minimum three generations of particles are necessary.


title: Large Neutrino Mixing from Small Quark and Lepton Mixings

abstract:
  We discuss the special class of models where nearly maximal neutrino mixing
is produced through the see-saw mechanism, starting from only nearly diagonal
matrices for charged leptons, Dirac neutrinos and Majorana right-handed
neutrinos.


title: Time evolution of correlation functions and thermalization

abstract:
  We investigate the time evolution of a classical ensemble of isolated
periodic chains of O(N)-symmetric anharmonic oscillators. Our method is based
on an exact evolution equation for the time dependence of correlation
functions. We discuss its solutions in an approximation which retains all
contributions in next-to-leading order in a 1/N expansion and preserves time
reflection symmetry. We observe effective irreversibility and approximate
thermalization. At large time the system approaches stationary solutions in the
vicinity of, but not identical to, thermal equilibrium. The ensemble therefore
retains some memory of the initial condition beyond the conserved total energy.
Such a behavior with incomplete thermalization is referred to as "mesoscopic
dynamics". It is expected for systems in a small volume. Surprisingly, we find
that the nonthermal asymptotic stationary solutions do not change for large
volume. This raises questions on Boltzmann's conjecture that macroscopic
isolated systems thermalize.


title: On Nonperturbative Calculations in Quantum Electrodynamics

abstract:
  A new approach to nonperturbative calculations in quantum electrodynamics is
proposed. The approach is based on a regular iteration scheme for solution of
Schwinger-Dyson equations for generating functional of Green functions. The
approach allows one to take into account the gauge invariance conditions (Ward
identities) and to perform the renormalization program. The iteration scheme
can be realized in two versions. The first one ("perturbative vacuum")
corresponds to chain summation in the diagram language. In this version in
four-dimensional theory the non-physical singularity (Landau pole) arises which
leads to the triviality of the renormalized theory. The second version
("nonperturbative vacuum") corresponds to ladder summation and permits one to
make non-perturbative calculations of physical quantities in spite of the
triviality problem. For chiral-symmetrical leading approximation two terms of
the expansion of the first-step vertex function over photon momentum are
calculated. A formula for anomalous magnetic moment is obtained. A problem of
dynamical chiral symmetry breaking (DCSB) is considered, the calculations are
performed for renormalized theory in Minkowsky space. In the strong coupling
region DCSB-solutions arise. For the renormalized theory a DCSB-solution is
also possible in the weak coupling region but with a subsidiary condition on
the value of $\alpha$.


title: Anomalous Currents and Gluon Condensates in QCD at Finite Temperature

abstract:
  After a short description of the currents coming from the known conservation
laws in classical physics, we look at some further cases which arise after
quantization in relation to quantum chromodynamics (QCD) at finite temperature.
In these cases, however, some basic changes appear with the anomalies. First we
go into the relationship between the trace of the energy momentum tensor and
the gluon condensate at finite temperature. Using the recent numerical data
from the simulations of lattice guage theory we present the computational
evaluations for the gluon condensates at finite temperature. Thereafter we
discuss the effects of chiral symmetry breaking and its restoration at finite
temperature through the chiral phase transition. In this context we investigate
the properties of the gluon condensate in the presence of massive dynamical
quarks using numerical data. Finally we put together these results with a
discussion of the various anomalous currents and their relationship to our
findings here.


title: Identification of Colour Reconnection using Factorial Correlator

abstract:
  A new signal is proposed for the colour reconnection in the hadronic decay of
W+ W- in e+e- collisions. Using Pythia Monte Carlo it is shown that this
signal, being based on the factorial correlator, is more sensitive than the
ones using only averaged quantities.


title: The asymptotic behavior of the pi^0 gamma^* gamma transition

abstract:
  It is discussed how various Ans"atze for the dressed quark-photon (qq gamma)
vertices Gamma^mu(q,q') influence the asymptotics of the gamma^* gamma -> pi^0
transition form factor.


title: A new model for the quark mass matrices

abstract:
  I present a new model for the quark mass matrices, which uses four scalar
doublets together with a horizontal symmetry S3 x Z3. The model is inspired on
a suggestion made a few years ago by Ma, but it is different. The predictions
|Vts| \approx ms/mb and |Vub/Vcb| > 0.085 are obtained. Flavour-changing
neutral Yukawa interactions do not exist in the down-type-quark sector.


title:
Two-point function of strangeness-carrying vector-currents in two-loop
  Chiral Perturbation Theory

abstract:
  We calculate the correlator between two external vector-currents having the
quantum-numbers of a charged kaon. We give the renormalized expression to two
loops in standard chiral perturbation theory in the isospin limit, which, as a
physical result, is finite and scale-independent. Applications include a low
energy theorem, valid at two loop order, of a flavor breaking combination of
vector current correlators as well as a determination of the phenomenologically
relevant finite $O(p^6)$-counterterm combination $Q_V$ by means of inverse
moment finite energy sum rules. This determination is less sensitive to
isospin-breaking effects than previous attempts.