title: Dynamics of Metastable Vacua in the Early Universe

abstract:
  We study the question whether a possible metastable vacuum state is actually
populated in a phase transition in the early universe, as is usually assumed in
the discussion of vacuum stability bounds e.g. for Standard Model parameters. A
phenomenological (3+1)-dimensional Langevin equation is solved numerically for
a toy model with a potential motivated by the finite temperature 1-loop
effective potential of the Standard Model including additional
non-renormalizable operators from an effective theory for physics beyond the
Standard Model and a time dependent temperature. It turns out that whether the
metastable vacuum is populated depends critically on the value of the
phenomenological parameter eta for small scalar couplings. For large enough
scalar couplings and with our specific form of the non-renormalizable operators
the system (governed by the Langevin equation) always ends up in the metastable
minimum.


title: Charges from Dressed Matter: Physics and Renormalisation

abstract:
  Gauge theories are characterised by long range interactions. Neglecting these
interactions at large times, and identifying the Lagrangian matter fields with
the asymptotic physical fields, leads to the infra-red problem. In this paper
we study the perturbative applications of a construction of physical charges in
QED, where the matter fields are combined with the associated electromagnetic
clouds. This has been formally shown, in a companion paper, to include these
asymptotic interactions. It is explicitly demonstrated that the on-shell
Green's functions and S-matrix elements describing these charged fields have,
to all orders in the coupling, the pole structure associated with particle
propagation and scattering. We show in detail that the renormalisation
procedure may be carried out straightforwardly. It is shown that standard
infra-red finite predictions of QED are not altered and it is speculated that
the good infra-red properties of our construction may open the way to the
calculation of previously uncalculable properties. Finally extensions of this
approach to QCD are briefly discussed.


title: The (BFKL) Pomeron-virtual photon-photon vertex for any conformal spin

abstract:
  To study diffractive photon production at HERA, we compute the projection of
the virtual photon-photon impact-factor on the BFKL leading-order
eigenfunctions E(n,nu) for non-zero transfer. This calculation supplements
former ones performed for n=0. We provide an expression for n=+/-2 and check
that all the other components are zero.


title: Atmospheric Neutrinos: Past, Present and

abstract:
  This paper reviews the history of the atmospheric neutrino anomaly. The
historical record does not support more recent claims that the anomaly
constitutes evidence for a neutrino mass. Most experiments have reported an
apparent muon deficiency which is independent of energy and distance. Time
dependent variations in the Super Kamioka results are noted.


title: Muon Decay and Physics Beyond the Standard Model

abstract:
  This article reviews the current theoretical and experimental status of the
field of muon decay and its potential to search for new physics beyond the
Standard Model. The importance of rare muon processes with lepton flavor
violation is highly stressed, together with precision measurements of normal
muon decay. Recent up-to-date motivations of lepton flavor violation based on
supersymmetric models, in particular supersymmetric grand unified theories, are
described along with other theoretical models. Future prospects of experiments
and muon sources of high intensity for further progress in this field are also
discussed.


title:
Signature of Charged to Neutral Higgs Boson Decay at the LHC in SUSY
  Models

abstract:
  We study the signature of $H^\pm$ decay into $h^0W$ at the LHC in SUSY
models. It has only marginal viability in the MSSM. But in the singlet
extensions like the NMSSM one can have a spectacular signature for $H^\pm$
decay into $(h^0,A^0)W$ over a significant domain of parameter space.


title:
Thermal Photons and Lepton Pairs from Quark Gluon Plasma and Hot
  Hadronic Matter

abstract:
  The formulation of the real and virtual photon production rate from strongly
interacting matter is presented in the framework of finite temperature field
theory. The changes in the hadronic spectral function induced by temperature
are discussed within the ambit of the Walecka type model, gauged linear and
non-linear sigma models, hidden local symmetry approach and QCD sum rule
approach. Possibility of observing the direct thermal photon and lepton pair
from quark gluon plasma has been contrasted with those from hot hadronic matter
with and without medium effects for various mass variation scenarios. At SPS
energies, in-medium effects of different magnitude on the hadronic properties
for the Walecka model, Brown-Rho scaling and Nambu scaling scenarios are
conspicuously visible through the low invariant mass distribution of dilepton
and transverse momentum spectra of photon. However, at RHIC energies the
thermal photon (dilepton) spectra originating from Quark Gluon Plasma
overshines those from hadronic matter for large transverse momentum (invariant
mass) irrespective of the models used for evaluating the finite temperature
effects on the hadronic properties. It is thus expected that both at RHIC and
LHC energies the formation of Quark Gluon Plasma in the initial stages may
indeed turn out to be a realistic scenario.


title:
Are the neutrino masses and mixings closely related to the masses and
  mixings of quarks?

abstract:
  The mass matrices of quarks have a simple structure if expressed in powers of
the small parameter \sigma=(m_c/m_t)^{1/2}. If there is a close relation
between quarks and leptons, one would expect similar structures for the lepton
matrices which involve the same parameter. To have a specific proposal, the
see-saw mechanism is employed together with the stringent requirement that the
singlet neutrinos carry non-zero generation charges. These charges then
determine the powers of \sigma in the corresponding heavy neutrino mass matrix.
As a result, the neutrino mixing matrix turns out to be of the bimaximal type.
In addition, the mass splitting of the two lightest neutrinos is found to be
tiny, and just of the correct magnitude necessary for the vacuum solution for
solar neutrinos.


title: The Mellin moments of deep inelastic structure functions at two loops

abstract:
  We perform the analytic calculation of the Mellin moments of the structure
functions F_2 and F_L in perturbative QCD up to second order corrections and in
leading twist approximation. We calculate the 2-loop contributions to the
anomalous dimensions of the singlet and non-singlet operator matrix elements
and the 2-loop coefficient functions of F_2 and F_L. Our results are in
agreement with earlier calculations in the literature.


title: Hard exclusive photoproduction of $\Phi$ and $J/\Psi$ mesons

abstract:
  We consider the reaction $\gamma p \to M p$, with M being either a $\Phi$ or
a $J/\Psi$ meson, within perturbative QCD treating the proton as a
quark-diquark system. The phenomenological couplings of gauge bosons to
(spatially extended) diquarks and the quark-diquark distribution amplitude of
the proton are adopted from previous investigations of baryon form factors and
two-photon processes. Going beyond leading order, we take into account
hadron-mass effects by a systematic expansion in the small parameter (hadron
mass/ photon energy). With the meson distribution amplitudes taken from the
literature our predictions for the differential cross section at $| t | \agt 3
\hbox{GeV}^2$ seem to provide a reasonable extrapolation of the low-$t$ data in
case of the $\Phi$. They fail, however, completely for the $J/\Psi$. A closer
inspection reveals that `` hadron-mass corrections\rq\rq become dominant for t
values of only a few GeV in case of the $J/\Psi$. This indicates that one has
to go to much larger energies and momentum transfers in order to achieve a
reliable description of $J/\Psi$ production within the hard-scattering
approach.


title:
On the Resummation of Subleading Logarithms in the Transverse Momentum
  Distribution of Vector Bosons Produced at Hadron Colliders

abstract:
  The perturbation series for electroweak vector boson production at small
transverse momentum is dominated by large double logarithms at each order in
perturbation theory. An accurate theoretical prediction therefore requires a
resummation of these logarithms. This can be performed either directly in
transverse momentum space or in impact parameter (Fourier transform) space.
While both approaches resum the same leading double logarithms, the subleading
logarithms are, in general, treated differently. We comment on two recent
approaches to this problem, emphasising the particular subleading logarithms
resummed in each case and the numerical differences in the cross sections which
result.


title:
Hard Polarized Photon Emission in Single Crystals by High Energy
  Electrons for Planar Crystal Orientations

abstract:
  The radiation emission spectra of polarized photons emitted from charge
particle in single crystal are obtained in semiclassical theory in
Baer-Katkov-Strakhovenko approximation for planar crystal orientation. The
range of applicability of this approximation is estimated by comparing the
results with calculations in exact semiclassical theory. Optimal crystal
orientations for producing unpolarized and polarized photon beams are also
founded.


title: The gamma^* gamma -> pi^0 transition in a bound-state approach

abstract:
  We present a recent treatment of the $\pi^0\gamma^\star\gamma$ transition
form factor in the coupled Schwinger-Dyson and Bethe-Salpeter approach to
stress the desirability of measuring it at CEBAF.


title: Vacuum Condensates and the Anomalous Magnetic Moment of a Dirac Fermion

abstract:
  We address anticipated fermion-antifermion and dimension-4 gauge-field
vacuum-condensate contributions to the magnetic portion of the fermion-photon
vertex function in the presence of a vacuum with nonperturbative content, such
as that of QCD. We discuss how inclusion of such condensate contributions may
lead to a vanishing anomalous magnetic moment, in which case vacuum condensates
may account for the apparent consistency between constituent quark masses
characterizing baryon magnetic moments and those characterizing baryon
spectroscopy.


title: Real CP violation in a simple extension of the standard model

abstract:
  I present a simple three-Higgs-doublet extension of the standard model in
which real CP violation takes place. The strong CP problem is attenuated by
this model.


title: Remarks on Form Factor Bounds

abstract:
  Improved model independent upper bounds on the weak transition form factors
are derived using inclusive sum rules. Comparison of the new bounds with the
old ones is made for the form factors h_{A_1} and h_V in B -> D* decays.


title: Weak Matrix Elements without Quark Masses on the Lattice

abstract:
  We introduce a new parameterization of four-fermion matrix elements which
does not involve quark masses and thus allows a reduction of systematic
uncertainties in physical amplitudes. As a result the apparent quadratic
dependence of e'/e on m_s is removed. To simplify the matching between lattice
and continuum renormalization schemes, we express our results in terms of
Renormalization Group Invariant B-parameters which are renormalization-scheme
and scale independent. As an application of our proposal, matrix elements of
DeltaI=3/2 and SUSY DeltaF=2 (F=S,C,B) four-fermion operators have been
computed.


title:
One-pion transitions between heavy baryons in the constituent quark
  model

abstract:
  Single pion transitions of S wave to S wave, P wave to S wave and P wave to P
wave heavy baryons are analyzed in the framework of the Heavy Quark Symmetry
limit (HQS). We use a constituent quark model picture for the light diquark
system with an underlying SU(2N_{f}) X O(3) symmetry to reduce the number of
the HQS coupling factors required to describe these transitions. We also use
the quantum theory of angular momentum to rewrite the one-pion transitions
constituent quark model results in a more general form using the 6j- and
9j-symbols. We finally estimate the decay rates of some single pion transitions
between charm baryon states.


title: Neutrino Oscillations in a "Predictive" SUSY GUT

abstract:
  New data on neutrino masses is very exciting. It is the first evidence for
physics beyond the standard model. In this talk we discuss this data and how it
may (or may not) be used to constrain theories of charged fermion masses. The
talk is divided into two parts. In part I, we briefly discuss the theoretical
framework for fermion masses and mixing angles as well as some of the most
salient data for neutrino oscillations. In part II, we define the framework of
a "predictive" theory of fermion masses. We then consider a particular theory
which makes significant testable predictions.


title: Analyses of Long Lived Slepton NLSP in GMSB Model at Linear Collider

abstract:
  We performed an analysis on the detection of a long lived stau at a linear
collider with $\sqrt{s}=500$ GeV. In GMSB models a long lived NLSP is predicted
for large value of the supersymmetry breaking scale F. Furthermore in a large
portion of the parameter space this particle is a stau. Such heavy charged
particles will leave a track in the tracking volume and hit the muon detector.
  In order to disentangle this signal from the muon background we explore
kinematics and particle identification tools: time of flight device, dE/dX and
Cerenkov devices.


title:
Decoupling Solution to the Supersymmetric Flavor Problem without Color
  Instability

abstract:
  The supersymmetric flavor problem is elegantly solved by the decoupling
scenario, where the first-two generation sfermions are much heavier than the
third generation ones. However, such a mass spectrum is not stable against
renormalization group evolution and causes extreme fine-tuning of the
electroweak symmetry breaking. We present a mechanism which stabilizes the mass
spectrum with such a large splitting, by introducing extra vector-like chiral
multiplets of masses comparable to the first-two generation sfermions. The
explicit models are constructed in a framework of the anomalous U(1)
SUSY-breaking model.


title: Photon Production of Axionic Cold Dark Matter

abstract:
  Using the non-equilibrium quantum field theory, photon production from the
coherently oscillating axion field in a flat Robertson-Walker cosmology is
re-examined. First neglecting the Debye screening of the baryon plasma to
photons, we find that the axions will dissipate into photons via spinodal
instability in addition to parametric resonance. As a result of the
pseudo-scalar nature of the axion-photon coupling, we observe a circular
polarization asymmetry in the produced photons. However, these effects are
suppressed to an insignificant level in the expanding universe. We then briefly
discuss a systematic way of including the plasma effect which can further
suppress the photon production. We note that the formalism of the problem can
be applied to any pseudo-scalar field coupled to photon in a thermal background
in a general curved spacetime.


title: Measurement of the photon structure function at ALEPH

abstract:
  The photon structure function F2gamma has been measured with data taken by
the ALEPH collaboration at LEP centre-of-mass energies sqrt s = 91 GeV with <
Q^2 > of 9.9, 20.7 and 284 GeV^2 and sqrt s = 183 GeV with < Q^2 > of 13.7 and
56.5 GeV^2. For the data at sqrt s = 183 GeV a two-dimensional unfolding method
employing the principle of maximum entropy is used, which reduces the errors
compared to one-dimensional methods.


title: Chiral Perturbation Theory with Virtual Photons and Leptons

abstract:
  We construct a low-energy effective field theory which allows the full
treatment of isospin-breaking effects in semileptonic weak interactions. To
this end, we enlarge the particle spectrum of chiral perturbation theory with
virtual photons by including also the light leptons as dynamical degrees of
freedom. Using super-heat-kernel techniques, we determine the additional
one-loop divergences generated by the presence of virtual leptons and give the
full list of associated local counterterms. We illustrate the use of our
effective theory by applying it to the decays pi -> l nu_{l} and K -> l nu_{l}.


title:
The Phenomenology of the Lightest Pseudo Nambu Goldstone Boson at Future
  Colliders

abstract:
  The capability of the linear collider to discover and study the lightest
neutral pseudo-Nambu-Goldstone boson P_0 of dynamical symmetry breaking models
in the e+e- and gamma gamma modes is presented. For a number of technicolor
N_TC=4, the discovery of the P_0 at an e+e- collider via the reaction e+e- ->
gamma P_0 should be possible for an integrated luminosity of L=100 fb^-1 at
E=500 GeV as long as m_{P_0} is not near m_Z. In the gamma gamma collider mode
the gamma gamma -> P_0 -> b anti b signal should be very robust and could be
measured with high statistical accuracy for a broad range of m_{P_0} if N_TC=4.


title: Neutrino afterglow from Gamma-Ray Bursts: ~10^{18} eV

abstract:
  We show that a significant fraction of the energy of a gamma-ray burst(GRB)
is probably converted to a burst of 10^{17}-10^{19} eV neutrinos and multiple
GeV gammas that follow the GRB by > 10 s . If, as previously suggested, GRB's
accelerate protons to ~10^{20} eV, then both the neutrinos and the gammas may
be detectable.


title: Some notes about multiplicity distribution at hadron colliders

abstract:
  The idea that the hard processes are dominate at the very high multiplicity
(VHM) final states creation is considered. For this purpose quantitative
realization of the Pomeron, DIS and large-angle annihilation (LAA) mechanism
combinations are considered in the pQCD frame. The phase transition
(condensation) in the soft pions system is described as the alternative to
above mechanism. It is shown that in compared to QCD prediction last one
predicts enhancement in the VHM distribution tail.


title:
The Source Size Dependence on the M_hadron Applying Fermi and Bose
  Statistics and I-Spin Invariance

abstract:
  The emission volume sizes of pions and Kaons, r_{\pi^\pm \pi^\pm} and
r_{K^\pm K^\pm}, measured in the hadronic Z^0 decays via the Bose-Einstein
Correlations (BEC), and the recent measurements of r_{\Lambda\Lambda} obtained
by through the Pauli exclusion principle are used to study the r dependence on
the hadron mass. A clear r_{\pi^\pm \pi^\pm} > r_{K^\pm K^\pm} > r_{\Lambda
\Lambda} hierarchy is observed which seems to disagree with the basic string
(LUND) model expectation. An adequate description of r(m) is obtained via the
Heisenberg uncertainty relations and also by Local Parton Hadron Duality
approach using a general QCD potential. These lead to a relation of the type
r(m) ~ Constant/sqrt{m}.
  The present lack of knowledge on the f_o(980) decay rate to the K^0\bar{K}^0
channel prohibits the use of the r_{K^0_SK^0_S} in the r(m) analysis. The use
of a generalised BEC and I-spin invariance, which predicts an BEC enhancement
also in the K^{\pm}K^0 and \pi^{\pm}\pi^0 systems, should in the future help to
include the r_{K^0_SK^0_S} in the r(m) analysis.


title: A Semianalytical Method to Solve Altarelli-Parisi Evolution Equations

abstract:
  We discuss a new method to solve in a semianalytical way the
Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations at NLO order in
the x-space. The method allows to construct an evolution operator expressed in
form of a rapidly convergent series of matrices, depending only on the
splitting functions. This operator, acting on a generic initial distribution,
provides a very accurate solution in a short computer time (only a few
hundredth of second). As an example, we apply the method, useful to solve a
wide class of systems of integrodifferential equations, to the polarized parton
distributions


title: Bounds on New Physics from Parity Violation in Atomic Cesium

abstract:
  A recent experimental determination of the weak charge of atomic cesium is
used to get implications for possible new physics. The new data imply positive
upper and lower bounds on the new physics contribution to the weak charge,
delta_N Q_W, requiring new physics of a type not severely constrained by the
high energy precision data.


title:
Finding neutral Higgs bosons in a two-Higgs-doublet model with
  spontaneous CP violation

abstract:
  We consider a particular two-Higgs-doublet model with spontaneous CP
violation, where two neutral Higgses have no definite CP properties and the
third one is CP-even. In this model, as the parameter $\theta$ of CP violation
increases, the masses of the neutral Higgs bosons are drawn towards the mass of
the lightest one and the chance of detection of neutral Higgses at an $e^+e^-$
collider in Z+Higgs, $b\bar{b}$+Higgs and $t\bar{t}$+Higgs production increases
with respect to the CP conserving case.


title: N_f Dependence of the Quark Condensate from a Chiral Sum Rule

abstract:
  How fast does the quark condensate in QCD-like theories vary as a function of
$N_f$ is inferred from real QCD using chiral perturbation theory at order
one-loop. A sum rule is derived for the single relevant chiral
coupling-constant, $L_6$. A model independent lower bound is obtained. The
spectral function satisfies a Weinberg-type superconvergence relation. It is
discussed how this, together with chiral constraints allows a solid evaluation
of $L_6$, based on experimental $\pi\pi-K\bar K$ S-wave T-matrix input. The
resulting value of $L_6$ is compatible with a strong $N_f$ dependence possibly
suggestive of the proximity of a chiral phase transition


title: A Mass Matrix for Atmospheric, Solar, and LSND Neutrino Oscillations

abstract:
  We construct a mass matrix for the four neutrino flavors, three active and
one sterile, needed to fit oscillations in all three neutrino experiments:
atmospheric, solar, and LSND, simultaneously. It organizes the neutrinos into
two doublets whose central values are about 1 eV apart, and whose splittings
are of the order of 10^(-3) eV. Atmospheric neutrino oscillations are described
as maximal mixing within the upper doublet, and solar as the same within the
lower doublet. Then LSND is a weak transition from one doublet to the other. We
comment on the Majorana versus Dirac nature of the active neutrinos and show
that our mass matrix can be derived from an S_2 x S_2 permutation symmetry plus
an equal splitting rule.


title: Study of Extra Space Dimensions in Vector Boson Pair Production at LEP

abstract:
  Recent theoretical scenarios propose that quantum gravity effects may
manifest at LEP energies by means of gravitons that couple to Standard Model
particles and propagate into extra space dimensions. These predictions are
checked against the most recent experimental results on photon, W and Z pair
production. No deviations from the Standard Model expectations are found and
limits of the order of 1 TeV on the scale of these models are set.


title: BFKL signatures at a linear collider

abstract:
  The BFKL dynamics can be successfully tested at the future high energy
$e^+e^-$ linear collider. The total $\gamma^*\gamma^*$ cross-section is
calculated in the Leading Log QCD dipole picture of BFKL dynamics, and compared
with the one from 2-gluon exchange. The rapidity dependence of the
cross-section remains a powerful tool to increase the ratio between the BFKL
and the 2-gluon cross-sections and is more sensitive to BFKL effects, even in
the presence of higher order corrections. Other potential signals like
diffractive $J/ \Psi$ and 'forward' jet productions will also be discussed.


title:
A Two-dimensional Model with Chiral Condensates and Cooper Pairs having
  QCD-like Phase Structure

abstract:
  We generalize our previous model to an O(N) symmetric two-dimensional model
which possesses chiral symmetry breaking and superconducting (Cooper pair
condensates) phases at large-N. At zero temperature and density, the model can
be solved analytically in the large-N limit. We perform the renormalization
explicitly and obtain a closed form expression of the effective potential.
There exists a renormalization group invariant parameter $\delta$ that
determines which of the condensates exist in the vacuum. At finite temperatures
and densities, we map out the phase structure of the model by a detailed
numerical analysis of the renormalized effective potential. For $\delta$
positive and sufficiently large, the phase diagram in the $\mu$-$T$ (chemical
potential-temperature) plane exactly mimics the features expected for QCD with
two light flavors of quarks. At low temperatures there exists low-$\mu$ chiral
symmetry breaking and high-$\mu$ Cooper pair condensate regions which are
separated by a first-order phase transition. At high $\mu$, when the
temperature is raised, the system undergoes a second-order phase transition
from the superconducting phase to an unbroken phase in which both condensates
vanish. For a range of values of $\delta$ the theory possesses a tricritical
point ($\mu_{tc}$ and $T_{tc}$); for $\mu > \mu_{tc}$ ($\mu < \mu_{tc}$) the
phase transition from the low temperature chiral symmetry breaking phase to
unbroken phase is first-order (second-order). For the range of $\delta$ in
which the system mimics QCD, we expect the model to be useful for the
investigation of dynamical aspects of nonequilibrium phase transitions, and to
provide information relevant to the study of relativistic heavy ion collisions
and the dense interiors of neutron stars.


title: Trojan Penguins and Isospin Violation in Hadronic B Decays

abstract:
  Some rare hadronic decays of B mesons, such as B->pi K, are sensitive to
isospin-violating contributions from physics beyond the Standard Model.
Although commonly referred to as electroweak penguins, such contributions can
often arise through tree-level exchanges of heavy particles, or through
strong-interaction loop diagrams. The Wilson coefficients of the corresponding
electroweak penguin operators are calculated in a large class of New Physics
models, and in many cases are found not to be suppressed with respect to the
QCD penguin coefficients. Several tests for these effects using observables in
B->pi K decays are discussed, and nontrivial bounds on the couplings of the
various New Physics models are derived.


title:
CLEO measurement of $B \to \pi^+ \pi^-$ and determination of weak phase
  $\alpha$

abstract:
  The CLEO collaboration has recently reported a (first) measurement of $BR (B
\to \pi^+ \pi^-) = (4.7^{+1.8}_{-1.5} \pm 0.6) \times 10^{-6}$. We study, using
recent results on QCD improved factorization, the implications of this
measurement for the determination of the CKM phase $\alpha$ and also for the
rate for $B \to \pi^0 \pi^0$. If the $B \to \pi^-$ form factor is large
$(\stackrel{>}{\sim} 0.3)$, then we find that the CLEO measurement favors small
$|V_{ub}/V_{cb}|$ so that the expected error (due to neglecting the QCD penguin
amplitude) in the measurement of $\alpha$ using {\em only} the time-dependent
analysis of the decay $B \to \pi^+ \pi^-$ is large $\sim 15^{\circ}$. However,
if $|V_{ub}/V_{cb}|$ is known, then it is possible to determine the correct
value of $\sin 2 \alpha$.


title: Getting bounds on the mixing angles for a non-sequential bottom quark

abstract:
  We analyze the vertex Zff in the framework of models that add a new bottom
quark in a nonsequential way and we evaluate the tree level contribution to
LEP/SLC data $R_{b}$, $R_{l}$ and the total Z width $\Gamma_{Z}$. We obtain
bounds for the mixing angles through the experimentally allowed contour regions
of the parameters $\Lambda_{L,R}$ introduced here. In order to get a more
restrictive region, we also consider the experimental results for $B\to \nu \nu
X$ as well.


title: Twist-3 polarized structure functions

abstract:
  We review the nucleon's twist-3 polarized structure functions from the
viewpoint of gauge invariant, nonlocal light-cone operators in QCD. We discuss
a systematic treatment of the polarized structure functions and the
corresponding parton distribution functions. We emphasize unique features of
higher twist distributions, and the role of the QCD equations of motion to
derive their anomalous dimensions for Q^2-evolution.


title: Search for CP Violation at a Neutrino Factory in a Four-Neutrino Model

abstract:
  The CP violation effects in long baseline neutrino oscillations are studied
in the framework of a four-neutrino model (three active neutrinos and one
sterile neutrino). It is assumed that neutrino masses are devided into two
nearly degenerate pairs, as indicated by the oscillation data. Approximative
analytic expressions are derived for the probability differences $\Delta
P_{\a\b} \equiv P(\nu_\alpha \to \nu_\beta)- P(\bar\nu_\alpha \to
\bar\nu_\beta)$ taking into account the CP violation effect of the Earth's
crust. The matter effect is found to be small compared with the genuine CP
violation term, in contrast with the three-neutrino model.


title:
Quark Family Discrimination and Flavour-Changing Neutral Currents in the
  SU(3)_C X SU(3)_L X U(1) Model with Right-Handed Neutrinos

abstract:
  Contributions of flavour-changing neutral currents in the 3 3 1 model with
right-handed neutrinos to mass difference of the neutral meson system $\Delta
m_P (P = K, D, B)$ are calculated. Using the Fritzsch anzats on quark mixing,
we show that the third family should be different from the first two. We obtain
a lower bound on mass of the new heavy neutral gauge boson as 1.02 TeV.


title: CP Violation and the Light Quark Sector

abstract:
  In view of the observed strong hierarchy of quark masses, we discuss a new
description of flavor mixing which is particularly suited for models of quark
mass matrices based on flavor symmetries. The necessary and sufficient
conditions for CP violation are clarified. The emergence of CP violation is
primarily linked to a large phase difference (near 90^{\circ}) in the light
quark sector. The unitarity triangle is determined by the mass ratios of the
light quarks. We conclude that the unitarity triangle should be close or
identical to a rectangular triangle, and CP violation is maximal in this sense.


title: Maximal Neutrino Mixing and Maximal CP Violation

abstract:
  We propose a phenomenological model of lepton mixing and CP violation based
on the flavor democracy of charge leptons and the mass degeneracy of neutrinos.
A nearly bi-maximal flavor mixing pattern, which is favored by current data on
atmospheric and solar neutrino oscillations, emerges naturally from this model
after explicit symmetry breaking. The rephasing-invariant strength of CP or T
violation can be as large as one percent, leading to significant probability
asymmetries between \nu_\mu \to \nu_e and \bar{\nu}_\mu \to \bar{\nu}_e (or
\nu_e \to \nu_\mu) transitions in the long-baseline neutrino experiments.


title: Analytic Approach in Quantum Chromodynamics

abstract:
  We investigate a new ``renormalization invariant analytic formulation'' of
calculations in quantum chromodynamics, where the renormalization group
summation is correlated with the analyticity with respect to the square of the
transferred momentum $Q^2$. The expressions for the invariant charge and matrix
elements are then modified such that the unphysical singularities of the ghost
pole type do not appear at all, being by construction compensated by additional
nonperturbative contributions. Using the new scheme, we show that the results
of calculations for a number of physical processes are stable with respect to
higher-loop effects and the choice of the renormalization prescription. Having
in mind applications of the new formulation to inelastic lepton-nucleon
scattering processes, we analyze the corresponding structure functions starting
from the general principles of the theory expressed by the Jost-Lehmann-Dyson
integral representation. We use a nonstandard scaling variable that leads to
modified moments of the structure functions possessing K\"all\'en-Lehmann
analytic properties with respect to $Q^2$. We find the relation between these
``modified analytic moments'' and the operator product expansion.


title: The Auxiliary Mass Method beyond the Local Potential Approximation

abstract:
  We show that the evolution equation of the effective potential in the
auxiliary mass method corresponds to a leading approximation of a certain
series. This series is derived from an evolution equation of an effective
action using a derivative expansion. We derived an expression of the
next-to-leading approximation of the evolution equation, which is a
simultaneous partial differential equation.


title:
QCD sum rule analysis of the subleading Isgur-Wise form-factor
  tau_1(v.v') and tau_2(v.v') for B->D_1 l\bar\nu and B->D_2^* l\bar\nu

abstract:
  We present a QCD sum rule calculation of the Isgur-Wise form-factor
tau_1(v.v') and tau_2(v.v') for the semileptonic decays B->D_1(2420)l\bar\nu
and B->D_2^*(2460)l\bar\nu in the framework of heavy quark effective theory.
These two universal functions, associated with the matching of the weak
currents in QCD onto those in the effective theory, appear at the order 1/m_Q
in the heavy quark expansion of meson weak decay form factors.


title: Relic neutrino asymmetry, CMB and large-scale structure

abstract:
  We consider some consequences of the presence of a cosmological lepton
asymmetry in the form of neutrinos. A relic neutrino degeneracy enhances the
contribution of massive neutrinos to the present energy density of the
Universe, and modifies the power spectrum of radiation and matter. Comparing
with current observations of cosmic microwave background anisotropies and large
scale structure, we derive some constraints on the relic neutrino degeneracy
and on the spectral index in the case of a flat Universe with a cosmological
constant.


title: Chaos analyses in both phases of QED and QCD

abstract:
  We analyze the leading Lyapunov exponents of U(1) and SU(2) gauge field
configurations on the lattice which are initialized by quantum Monte Carlo
simulations. We find that configurations in the strong coupling phase are
substantially more chaotic than in deconfinement.


title:
Open charm production in deep inelastic scattering at next-to-leading
  order at HERA

abstract:
  An introduction and overview of charm production in deep inelastic scattering
at HERA is given. The existing next-to-leading order perturbative QCD
calculations are then reviewed, and key results are summarized. Finally,
comparisons are made with the most recent HERA data, and unresolved issues are
highlighted.


title: Perturbative QCD relations inspired by hypothetical tau leptons

abstract:
  We review our recent works on tests of perturbative QCD, inspired by the
relation between the hadronic decay of the tau lepton and the e+ e-
annihilation into hadrons. First, we present a set of commensurate scale
relations that probe the self-consistency of leading-twist QCD predictions for
any observable which defines an effective charge. These tests are independent
of the renormalization scheme and scale, and are applicable over wide data
ranges. As an example we apply this approach to R_{e+ e-}. Second, using a
differential form of these conmensurate scale relations, we present a method to
measure the QCD Gell-Mann--Low Psi function.


title: Final state interactions: from strangeness to beauty

abstract:
  I give a brief review of final state interactions in meson decays. I describe
possible effects of FSI in K, D and B systems, paying particular attention to
the description of the heavy meson decays. Available theoretical methods for
dealing with the effects of FSI are discussed.


title: The Metropolis algorithm for on-shell four-momentum phase space

abstract:
  We present several implementations of the Metropolis method, an adaptive
Monte Carlo algorithm, which allow for the calculation of multi-dimensional
integrals over arbitrary on-shell four-momentum phase space. The Metropolis
technique reveals itself very suitable for the treatment of high energy
processes in particle physics, particularly when the number of final state
objects and of kinematic constraints on the latter gets larger. We compare the
performances of the Metropolis algorithm with those of other programs widely
used in numerical simulations.


title:
Perturbative Color Transparency in Electron Beam Experiments via
  Impact-Parameter Factorization

abstract:
  Color transparency is a prediction of perturbative QCD. Yet detailed
calculations have been lacking, and aspects of the required factorization have
been controversial. We report on the first complete calculations entirely
within a perturbative QCD framework. We also comment on the underlying
factorization method and assumptions.


title:
s-Channel Production of MSSM Higgs Bosons at a Muon Collider with
  Explicit CP Violation

abstract:
  A muon collider with controllable energy resolution and transverse beam
polarization provides a powerful probe of the Higgs sector in the minimal
supersymmetric standard model with explicit CP violation, through s-channel
production of Higgs bosons. The production rates and the CP-even and CP-odd
transverse-polarization asymmetries are complementary in diagnosing CP
violation in the Higgs sector.


title:
On soft SUSY breaking parameters in string models with anomalous U(1)
  symmetry

abstract:
  We study the magnitudes of soft SUSY breaking parameters in heterotic string
models with anomalous U(1) symmetry. In most cases, D-term contribution to soft
scalar masses is expected to be comparable to or dominant over other
contributions provided that supersymmetry breaking is mediated by the
gravitational interaction and/or an anomalous U(1) symmetry and the magnitude
of vacuum energy is not more than of order $m_{3/2}^2 M^2$.


title: After Sitges

abstract:
  Summary talk given at the International Workshop on Linear Colliders LCWS 99,
Sitges (Barcelona), April 28 - May 5, 1999


title: Neutrino Oscillations and R-parity Violating Supersymmetry

abstract:
  Using the neutrino oscillations and neutrinoless double beta decay
experimental data we reconstructed an upper limit for the three generation
neutrino mass matrix. We compared this matrix with the predictions of the
minimal supersymmetric(SUSY) model with R-parity violation(\rp) and extracted
stringent limits on trilinear \rp coupling constants $\lambda_{i33},
\lambda'_{i33}$. Introducing an additional $U(1)_X$ flavor symmetry which had
been successful in explaining to relate various \rp parameters. In this model
we found a unique scenario for the neutrino masses and the \rp couplings
compatible with the neutrino oscillation data. Then we derived predictions for
certain experimentally interesting observables.


title: An alternative for righthanded neutrinos: lefthanded see--saw

abstract:
  A new lefthanded see-saw mechanism is constructed, implying both the
smallness of active-neutrino masses and decoupling of heavy passive neutrinos,
similarly to the situation in the case of conventional see-saw. But now, in
place of the conventional righthanded neutrinos, the lefthanded sterile
neutrinos play the role of heavy passive neutrinos, the righthanded neutrinos
and righthanded sterile neutrinos being absent. In this case, the neutrino mass
term is necessarily of pure Majorana type.


title: Forward Jet Production at HERA

abstract:
  We discuss forward jet production data recently published by the H1 and ZEUS
collaborations at HERA. We review how several Monte-Carlo models compare to the
data. QCD calculations based on the BFKL formalism and on fixed NLO
perturbation theory with and without resolved virtual photons are described.


title: Coherent Muon-Electron conversion in the Dualized Standard Model

abstract:
  Muon-electron conversion in nuclei is considered in the framework of the
Dualized Standard Model. The ratio $B_{\mu-e}$ of the conversion rate to the
total muon capture rate is derived, and computed for several nuclei in a
parameter-free calculation using parameters previously determined in different
physical contexts. The values obtained all lie within the present experimental
bounds, but some are so close as to seem readily accessible to experiments
already being planned. Similar considerations are applied also to muon-electron
conversion in muonium but give rates many orders of magnitude below the present
experiment limit.


title: Scalar Glueball--Quarkonium Mixing and the Structure of the QCD Vacuum

abstract:
  We use Ward identities of broken scale invariance to infer the amount of
scalar glueball--$\bar{q}q$ meson mixing from the ratio of quark and gluon
condensates in the QCD vacuum. Assuming dominance by a single scalar state, as
suggested by a phase-shift analysis, we find a mixing angle $\gamma \sim
36^{\circ}$, corresponding to near-maximal mixing of the glueball and
$\bar{s}s$ components.


title: Triplet Production by Linearly Polarized Photons

abstract:
  The process of electron-positron pair production by linearly polarized
photons is used as a polarimeter to perform mobile measurement of linear photon
polarization. In the limit of high photon energies, omega, the distributions of
the recoil-electron momentum and azimuthal angle do not depend on the photon
energy in the laboratory frame. We calculate the power corrections of order
m/omega to the above distributions and estimate the deviation from the
asymptotic result for various values of omega.


title:
Power corrections and the interplay between perturbative and
  non-perturbative phenomena

abstract:
  We discuss the issue of interplay between perturbative and non-perturbative
phenomena for power corrections to e+e- event shapes.


title: CP conserving constraints on Supersymmetric CP violation in the MSSM

abstract:
  We address the following question. Take the Constrained Minimal
Supersymmetric Standard Model (CMSSM) with the two CP violating SUSY phases
different from zero, and neglect the bound coming from the electric dipole
moment of the neutron (EDM): is it possible to fully account for CP violation
in the kaon and B systems using only the SUSY contributions with vanishing CKM
phase? We show that the ${BR}(B\to X_{s} \gamma)$ constraint, though CP
conserving, forces a negative answer to the above question. This implies that,
even in the regions of the CMSSM where a cancellation of different
contributions to the EDM allows for large SUSY phases, it is not possible to
exploit the SUSY phases to fully account for observable CP violation. Hence to
have sizeable SUSY contributions to CP violation, one needs new flavor
structures in the sfermion mass matrices beyond the usual CKM matrix.


title: Flavor at the TeV Scale with Extra Dimensions

abstract:
  Theories where the Standard Model fields reside on a 3-brane, with a low
fundamental cut-off and extra dimensions, provide alternative solutions to the
gauge hierarchy problem. However, generating flavor at the TeV scale while
avoiding flavor-changing difficulties appears prohibitively difficult at first
sight. We argue to the contrary that this picture allows us to lower flavor
physics close to the TeV scale. Small Yukawa couplings are generated by
``shining'' badly broken flavor symmetries from distant branes, and flavor and
CP-violating processes are adequately suppressed by these symmetries. We
further show how the extra dimensions avoid four dimensional disasters
associated with light fields charged under flavor. We construct elegant and
realistic theories of flavor based on the maximal U(3)^5 flavor symmetry which
naturally generate the simultaneous hierarchy of masses and mixing angles.
Finally, we introduce a new framework for predictive theories of flavor, where
our 3-brane is embedded within highly symmetrical configurations of
higher-dimensional branes.


title:
$\Lambda_b\to\Sigma_c^{(*)}\pi l{\bar\nu}$ in the heavy quark, chiral,
  and large $N_c$ limits

abstract:
  The decay of $\Lambda_b\to\Sigma_c^{(*)}\pi l{\bar\nu}$ processes are
calculated in the framework of heavy baryon chiral perturbation theory with
help of the $1/N_c$ expansion. The decay rate distributions over $v\cdot
v^{\prime}$ where $v$ and $v^{\prime}$ are the 4-vector velocities of
$\Lambda_b$ and $\Sigma_c^{(*)}$ respectively, and over the pion and lepton
energies are given. The decay branching ratios amount to about $1.21(0.971)%$
for $\Lambda_b\to\Sigma_c\pi l{\bar\nu}$ and $0.798(0.640)%$ for
$\Lambda_b\to\Sigma_c^*\pi l{\bar\nu}$ by using the baryonic Isgur-Wise
function predicted by QCD sum rule (large $N_c$ QCD).


title: Constituent Quarkstructur and $F^{p}_{2}$ Data

abstract:
  We have calculated the partonic structure of a constituent quark in the
leading order in QCD for the first time and examined its ipmlications on the
proton structure function, $F^{p}_{2}, data from HERA. It turned out that
although qualitatively it agrees with the data but for a finer refinement we
need to consider an {\it{inherent}} component due to gluons which act as the
binding agent between constituents quarks in the proton. Good agreement with
nucleon structure function, $F_{2}(x,Q^{2})$, for a wide range of $x=[10^{-6}
,1]$ and $Q^{2}=[0.5, 5000]$ $GeV^{2}$ is reached. {\bf{PACS Numbers 13.60 Hb,
12.39.-x, 13.88 +e, 12.20.Fv}}


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

abstract:
  We present our calculation of the correlator $<T\{V_sV_s^\dag\} >$ between
two external vector-currents with the quantum-numbers of a charged kaon. The
renormalized expression to $O(p^6)$ in $SU(3) \times SU(3)$ standard chiral
perturbation theory is finite and scale-independent. The result is used to
determine, via an IMFESR, the phenomenologically relevant finite
$O(p^6)$-counterterm combination $Q_V$ in a way which is not sensitive to
isospin breaking.


title:
0+ -> 2+ neutrinoless double beta decay triggered directly by the
  Majorana neutrino mass

abstract:
  We treat 0+ -> 2+ neutrinoless double beta decays taking into account recoil
corrections to the nuclear currents. The decay probability can be written as a
quadratic form of the effective coupling constants of the right-handed leptonic
currents and the effective neutrino mass. We calculate the nuclear matrix
elements for the 0+ -> 2+ neutrinoless double beta decays of 76Ge and 100Mo,
and demonstrate that the relative sensitivities of 0+ -> 2+ decays to the
neutrino mass and the right-handed currents are comparable to those of 0+ -> 0+
decays.


title: Massless Parton Asymptotics within Variable Flavour Number Schemes

abstract:
  In this note we formulate and investigate theoretical uncertainties for high
Q^2 deep inelastic heavy quark (charm, etc.) production rates which arise
within collinear resummation techniques from variations of the a priori unknown
charm input scale Q_0 of O(alpha_s) variable flavour number schemes. We show
that Q_0 variations constitute a source of considerable theoretical uncertainty
of present O(alpha_s) calculations within such schemes and we suggest to
consider a scale optimization from higher order corrections. We also outline
how the stability of the fixed order and collinearly resummed perturbation
series for heavy quark production can be comparatively investigated by
variation of Q_0.


title: Coherence of neutrino flavor mixing in quantum field theory

abstract:
  In the simplistic quantum mechanical picture of flavor mixing, conditions on
the maximum size and minimum coherence time of the source and detector regions
for the observation of interference---as well as the very viability of the
approach---can only be argued in an ad hoc way from principles external to the
formalism itself. To examine these conditions in a more fundamental way, the
quantum field theoretical $S$-matrix approach is employed in this paper,
without the unrealistic assumption of microscopic stationarity. The fully
normalized, time-dependent neutrino flavor mixing event rates presented here
automatically reveal the coherence conditions in a natural, self-contained, and
physically unambiguous way, while quantitatively describing the transition to
their failure.


title: CP Violating Phases, Nonuniversal Soft Breaking And D-brane Models

abstract:
  The question of CP violating phases and electric dipole moments (EDMs)for the
electron ($d_e$) and the neutron ($d_n$) for supergravity models with
nonuniversal soft breaking is considered for models with a light
($\stackrel{<}{\sim}$1 TeV) mass spectrum and R-parity invariance. As with
models with universal soft breaking (mSUGRA) one finds a serious fine tuning
problem generally arises for $\theta_{0B}$ (the phase of the B soft breaking
parameter at the GUT scale), if the experimental EDM constraints are obeyed and
radiative breaking of $SU(2)_L\times U(1)_Y$ occurs. A D-brane model where
$SU(3)_C\times U(1)_Y$ is associated with one set of 5-branes and $SU(2)_L$
with another intersecting set of 5-branes is examined, and the cancellation
phenomena is studied over the parameter space of the model. Large values of
$\theta_B$ (the phase of B at the electroweak scale) can be accommodated,
though again $\theta_{0B}$ must be fine tuned. Using the conventional
prescription for calculating $d_n$, one finds the region in parameter space
where the experimental EDM constraints on both $d_e$ and $d_n$ hold is
significantly reduced, and generally requires tan$\beta\stackrel{<}{\sim}$5 for
most of the parameter space, though there are small allowed regions even for
tan$\beta\stackrel{>}{\sim}$10. We find the Weinberg three gluon term generally
makes significant contributions, and results are sensitive to the values of
quark masses.


title: Focus Points and Naturalness in Supersymmetry

abstract:
  We analyze focus points in supersymmetric theories, where a parameter's
renormalization group trajectories meet for a family of ultraviolet boundary
conditions. We show that in a class of models including minimal supergravity,
the up-type Higgs mass has a focus point at the weak scale, where its value is
highly insensitive to the universal scalar mass. As a result, scalar masses as
large as 2 to 3 TeV are consistent with naturalness, and {\em all} squarks,
sleptons and heavy Higgs scalars may be beyond the discovery reaches of the
Large Hadron Collider and proposed linear colliders. Gaugino and Higgsino
masses are, however, still constrained to be near the weak scale. The focus
point behavior is remarkably robust, holding for both moderate and large
\tan\beta, any weak scale gaugino masses and A parameters, variations in the
top quark mass within experimental bounds, and for large variations in the
boundary condition scale.


title:
Radiative Corrections to the $Z b \bar{b}$ Vertex and Constraints on
  Extended Higgs Sectors

abstract:
  We explore the radiative corrections to the process $Z \to b \bar b$ in
models with extended Higgs sectors. The observables $R_b = \Gamma(Z \to b \bar
b)/\Gamma(Z \to \rm{hadrons})$ and the $Z b \bar b$ coupling asymmetry, $A_b =
(g_L^2 - g_R^2)/(g_L^2 + g_R^2)$, are sensitive to these corrections. We
present general formulae for the one-loop corrections to $R_b$ and $A_b$ in an
arbitrary extended Higgs sector, and derive explicit results for a number of
specific models. We find that in models containing only doublets, singlets, or
larger multiplets constrained by a custodial $SU(2)_{c}$ symmetry so that $M_W
= M_Z \cos\theta_W$ at tree level, the one-loop corrections due to virtual
charged Higgs bosons always worsen agreement with experiment. The $R_{b}$
measurement can be used to set lower bounds on the charged Higgs masses.
Constraints on models due to the one-loop contributions of neutral Higgs bosons
are also examined.


title: Four-loop Dyson-Schwinger-Johnson anatomy

abstract:
  Dyson-Schwinger equations are used to evaluate the 4-loop anomalous
dimensions of quenched QED in terms of finite, scheme-independent, 3-loop
integrals. Three of the results serve as strong checks of terms from
scheme-dependent 4-loop QCD calculations. The fourth, for the anomalous
dimension of $\bar\psi\sigma_{\mu\nu}\psi$, was previously known only to 2-loop
order. The 4-loop beta function has 24 unambiguous terms. Two of the simplest
give $\beta_4=\frac13(22-160)=-46$. The rational, $\zeta_3$ and $\zeta_5$ parts
of the other 22 miraculously sum to zero. Vertex anomalous dimensions have 40
terms, with no dramatic cancellations. Our methods come from work by the late
Kenneth Johnson, done more than 30 years ago. They are entirely free of the
subtractions and infrared rearrangements of later methods.


title: Doubly heavy baryons in sum rules of NRQCD

abstract:
  The masses of baryons containing two heavy quarks and their couplings to the
corresponding quark currents are evaluated in the framework of NRQCD sum rules.
The coulomb-like corrections in the system of doubly heavy diquark are taken
into account, and the contribution of nonperturbative terms coming from the
quark, gluon and mixed condensates as well as the product of quark and gluon
condensates, is analyzed. The higher condensates destroy the factorization of
baryon and diquark correlators and provide the convergency of sum rule method.
As a result the accuracy of estimates is improved.


title: Theory and Phenomenology of Instantons at HERA

abstract:
  We review our on-going theoretical and phenomenological investigation of the
prospects to discover QCD-instantons in deep-inelastic scattering at HERA.


title: Towards a complete $\gamma\gamma \to 4~$leptons Monte Carlo

abstract:
  The total cross-section of the $\gamma \gamma \to 4 $ leptons process is
known to have a large constant value at high energy, but a complete and exact
calculation of related differential spectra does not exist yet. However a
complete study of the process is important at NLC for luminosity measurements
or for background estimations. We here report on our various steps in that
direction, including the implementation of a first new calculation of helicity
amplitudes in a Monte-Carlo generator.


title: On the Origin of the Violation of Hara's Theorem for Conserved Current

abstract:
  I elaborate on the argument that the violation of Hara's theorem for
conserved current requires that the current is not sufficiently well localized.
It is also stressed that whatever sign of asymmetry is measured in the $\Xi ^0
\to \Lambda \gamma $ decay, one of the following three statements must be
incorrect: 1) Hara's theorem is satisfied, 2) vector meson dominance is
applicable to weak radiative hyperon decays, and 3) basic structure of our
quark-model description of nuclear parity-violation is correct.


title:
Field-Theoretical Treatment of Neutrino Oscillations: The Strength of
  the Canonical Oscillation Formula

abstract:
  We discuss conceptual aspects of neutrino oscillations with the main emphasis
on the field-theoretical approach. This approach includes the neutrino source
and detector processes and allows to obtain the neutrino transition or survival
probabilities as cross sections derived from the Feynman diagram of the
combined source - detection process. In this context, the neutrinos which are
supposed to oscillate appear as propagators of the neutrino mass eigenfields,
connecting the source and detection processes. We consider also the question
why the canonical neutrino oscillation formula is so robust against corrections
and discuss the nature of the oscillating neutrino state emerging in the
field-theoretical approach.


title: CP-violating asymmetry in B decays to 3 pseudoscalar mesons

abstract:
  The measurement of CP asymmetries in charged B meson decays might provide the
first demonstration of CP violation outside the K system. Among the usual three
CP-odd phases $\alpha$, $\beta$ and $\gamma$, the phase $\gamma$ seems to be
the most difficult to explore experimentally. In this talk I would like to
report on a recent analysis of the CP asymmetry in the partial widths for the
non-leptonic decays $B^{\pm} \to M {\bar M} \pi^{\pm}$ ($ M = \pi^+, K ^+,
\pi^0, \eta$), which results from the interference of the non-resonant decay
amplitude with the resonant amplitude for $B^{\pm} \to \chi_{c0} \pi^{\pm} $
followed by the decay $\chi_{c0} \to M {\bar M} $. The CP violating phase
$\gamma$ can be extracted from the measured asymmetry. We find that the partial
width asymmetry for $B^\pm \to \pi^+ \pi^- \pi^\pm$ is about $0.33~\sin
\gamma$, and about $0.45~ \sin \gamma$ for $B^\pm \to K^+ K^-\pi^\pm$, while it
is somewhat smaller for $B^\pm \to \pi^0 \pi^0 \pi^\pm$ and $B^\pm \to \eta
\eta \pi^\pm$.


title:
The Logarithmic Derivative of the F_{2} Structure Function and
  Saturation

abstract:
  We show that when screening corrections are included $\frac{\partial
F_{2}(x,Q^{2})}{\partial ln(Q^{2}/Q_{0}^{2})}$ is consistent with the behaviour
that one expects in pQCD. Screening corrections explain the enigma of the
Caldwell plot. Saturation has not been reached at present HERA energies.


title:
The small-x Behavior of the Nonsinglet Polarized Structure Function g_2
  in the Double Logarithmic Approximation

abstract:
  The nonsinglet spin dependent structure function $g_2(x,Q^2)$ is studied at
small x within the double logarithmic approximation of perturbative QCD. Both
positive and negative signature contributions are considered, and we find a
power-like growth in $1/x$. We discuss how our result fits into the
Wandzura-Wilczek relation.


title: $b \to s \gamma$ and CP violation in the MSSM

abstract:
  In this work, we study possible new contributions to $\epsilon_{K}$ and
$\epsilon_{B}$ in the MSSM with large supersymmetric phases. We show that, in
the CMSSM, the constrains coming from the experimental measure of the $b \to s
\gamma$ decay imply that these contributions are too small to be detected in CP
violation experiments with the available sensitivity.


title: PYTHIA and HERWIG for Linear Collider Physics

abstract:
  An overview is given of general-purpose event generators, especially PYTHIA
and HERWIG. The current status is summarized, some recent physics improvements
are described, and planned future projects are outlined.


title: Squeezed gluon vacuum and the global colour model of QCD

abstract:
  We discuss how the vacuum model of Celenza and Shakin with a squeezed gluon
condensate can explain the existence of an infrared singular gluon propagator
frequently used in calculations within the global colour model. In particular,
it reproduces a recently proposed QCD-motivated model where low energy chiral
parameters were computed as a function of a dynamically generated gluon mass.
We show how the strength of the confining interaction of this gluon propagator
and the value of the physical gluon condensate may be connected.


title: Thermal Dilepton Radiation at Intermediate Masses at the CERN-SpS

abstract:
  We investigate the significance of thermal dilepton radiation in the
intermediate-mass region in heavy-ion reactions at CERN-SpS energies. Within a
thermal fireball model for the space-time evolution, the radiation from hot
matter is found to dominate over hard 'background' processes (Drell-Yan and
open charm) up to invariant masses of about 2 GeV, with a rather moderate
fraction emerging from early stages with temperatures $T\simeq 175-200$ MeV
associated with deconfined matter. Further including a schematic acceptance for
the NA50 experiment we find good agreement with the observed enhancement in the
region 1.5 GeV~$<M_{\mu\mu}<$~3 GeV. In particular, there is no need to invoke
any anomalous open charm enhancement.


title: Mesino - Antimesino Oscillations

abstract:
  The phenomenological implications of supersymmetric theories with low scale
supersymmetry breaking and a squark as the lightest standard model superpartner
are investigated. Such squarks hadronize with light quarks, forming sbaryons
and mesinos before decaying. Production of these supersymmetric bound states at
a high energy collider can lead to displaced jets with large negative impact
parameter. Neutral mesino - antimesino oscillations are not forbidden by any
symmetry and can occur at observable rates with distinctive signatures. Stop
mesino - antimesino oscillations would give a sensitive probe of up-type
sflavor violation in the squark sector, and can provide a discovery channel for
supersymmetry through events with a same-sign top-top topology.


title: Neutrino Masses and Mixing with General Mass Matrices

abstract:
  We consider the most general neutrino masses and mixings including Dirac mass
terms, M_D, as well as Majorana masses, M_R and M_L. Neither the Majorana nor
the Dirac mass matrices are expected to be diagonal in the eigenbasis of weak
interactions, and so the resulting eigenstates of the Hamiltonian are
admixtures of $\SU(2)_L$ singlet and doublet fields of different
``generations.'' We show that for three generations each of doublet and singlet
neutrinos, diagonalization of the Hamiltonian to obtain the propagating
eigenstates in the general case requires diagonalization of a $12\times12$
Hermitian matrix, rather than the traditional $6\times6$ symmetric mass matrix.
The symmetries of the $12\times12$ matrix {\em are} such that it has 6 pairs of
real eigenvalues. Although the standard "see-saw" mechanism remains valid, and
indeed the eigenvalues obtained are identical to the standard ones, the correct
description of diagonalization and mixing is more complicated. The analogs of
the CKM matrix for the light and the heavy neutrinos are nonunitary, enriching
the opportunities for CP violation in the full neutrino sector.


title: Glueball production in hadron and nucleus collisions

abstract:
  The present discussion focusses on the dominant production of the 0++
glueball in central collisions in the suppressed yet observable channel 0++ -->
pi+ pi- l+ l-.


title: The t W- Mode of Single Top Production

abstract:
  The t W- mode of single top production is proposed as an important means to
study the weak interactions of the top quark. While the rate of this mode is
most likely too small to be observed at Run II of the Fermilab Tevatron, it is
expected to be considerably larger at the CERN LHC. In this article the
inclusive t W- rate is computed, including O(1 / log (m_t^2 / m_b^2))
corrections, and when combined with detailed Monte Carlo simulations including
the top and W decay products, indicate that the t W- single top process may be
extracted from the considerable t tbar and W+ W- j backgrounds at low
luminosity runs of the LHC.


title: Massless Metric Preheating

abstract:
  Can super-Hubble metric perturbations be amplified exponentially during
preheating ? Yes. An analytical existence proof is provided by exploiting the
conformal properties of massless inflationary models. The traditional conserved
quantity \zeta is non-conserved in many regions of parameter space. We include
backreaction through the homogeneous parts of the inflaton and preheating
fields and discuss the role of initial conditions on the post-preheating
power-spectrum. Maximum field variances are strongly underestimated if metric
perturbations are ignored. We illustrate this in the case of strong
self-interaction of the decay products. Without metric perturbations,
preheating in this case is very inefficient. However, metric perturbations
increase the maximum field variances and give alternative channels for the
resonance to proceed. This implies that metric perturbations can have a large
impact on calculations of relic abundances of particles produced during
preheating.


title:
Direct CP, T and/or CPT violations in the K^0-\bar{K^0} system -
  Implications of the recent KTeV results on $2\pi$ decays -

abstract:
  The recent results on the CP violating parameters Re(e'/e) and \Delta\phi =
\phi_{00}-\phi_{+-} reported by the KTeV Collaboration are analyzed with a view
to constrain CP, T and CPT violations in a decay process. Combining with some
relevant data compiled by the Particle Data Group, we find Re(e_2-e_0) = (0.85
+- 3.11)*10^{-4} and Im(e_2-e_0) = (3.2 +- 0.7)*10^{-4}, where Re(e_I) and
Im(e_I) represent respectively CP/CPT and CP/T violations in decay of K^0 and
\bar{K^0} into a 2\pi state with isospin I.


title:
Revising Neutrino Oscillation Parameter Space With Direct
  Flavor-Changing Interactions

abstract:
  We formulate direct, neutrino flavor-changing interactions in a framework
that fits smoothly with the parameterization of two-and three-state mixing of
massive neutrino states. We show that even small direct interaction strengths
could have important consequences for the interpretation of currently running
and proposed oscillation experiments. The oscillation amplitude and the borders
of the allowed regions in two-and three-flavor mixing parameter space can be
sensitieve to the presence of direct interactions when the transition
probability is small. We use extensively the high sensitivity of the NOMAD
experiment to illustrate potentially large effects from small, direct flavor
violation. In the purely leptonic sector, we find that the clean muon neutrino
and electron neutrino beams from a muon collider could provide the sharpest
tests of direct flavor violation.


title:
Heavy Quark Masses from the $Q\bar Q$ Threshold and the Upsilon
  Expansion

abstract:
  Recent results from studies using half the perturbative mass of heavy
quark-antiquark n=1, ${}^3S_1$ quarkonium as a new heavy quark mass definition
for problems where the characteristic scale is smaller than or of the same
order as the heavy quark mass are reviewed. In this new scheme, called the 1S
mass scheme, the heavy quark mass can be determined very accurately, and many
observables like inclusive B decays show nicely converging perturbative
expansions. Updates on results using the 1S scheme due to new higher order
calculations are presented.


title: Ruling out the Weinberg Model of Spontaneous CP Violation

abstract:
  There have been many declarations of the death of the Weinberg model of
spontaneous CP violation. Previous studies, before the recent measurements of
$\epsilon'/\epsilon$, indicated that the model could not accommodate the
experimental values on $\epsilon$ in $K^0-\bar K^0$ mixing, the neutron
electric dipole moment (EDM), the branching ratio of $b\to s \gamma$ and the
upper limit on $\epsilon'/\epsilon$. We point out that these studies were based
on optimistic estimates of the uncertainties in the calculations and that when
more realistic estimates of these errors are used the Weinberg model cannot be
conclusively ruled out from these considerations alone.
  Here we use these realistic error estimates to analyze the present situation
of the Weinberg model. The latest results from Belle and BaBar on $\sin 2
\beta$ allow the small values of this parameter which occur naturally in the
Weinberg model. However, in this model, the recently measured value of
$\Re(\epsilon'/\epsilon) = (1.92\pm 0.25)\times 10^{-3}$ cannot be made
compatible with the branching ratio $B(b\to s \gamma) = (3.15\pm0.54)\times
10^{-4}$. As a result we conclude that the Weinberg model is now confidently
and conservatively ruled out.


title:
Large parity violating effects in atomic dysprosium with nearly
  degenerate Floquet eigenvalues

abstract:
  In this article we study effects of parity nonconservation in atomic
dysprosium, where one has a pair of nearly degenerate levels of opposite
parity. We consider the time evolution of this two-level system within
oscillatory electric and magnetic fields. These are chosen to have a periodical
structure with the same period, such that a Floquet matrix describes the time
evolution of the quantum states. We show that, if the states are unstable, the
eigenvalues of the Floquet matrix may have contributions proportional to the
square root of the parity violating interaction matrix element $H_w$ while they
are almost degenerate in their parity even part. This leads to beat frequencies
proportional to $\sqrt{H_w}$ which are expected to be larger by several orders
of magnitude compared to ordinary P-violating contributions which are of order
$H_w$. However, for the simple field configurations we considered, it still
seems to be difficult to observe these P-violating beat effects, since the
states decay too fast. On the other hand, we found that, within only a few
Floquet cycles, very large parity violating asymmetries with respect to
experimental setups of opposite chirality may be obtained. The electric and
magnetic fields as well as the time intervals necessary for this are in an
experimentally accessible range. For statistically significant effects beyond
one standard deviation a number of about $10^7$ atoms is required. Our ideas
may be applied directly to other 2-level atomic systems and different field
configurations. We hope that these ideas will stimulate experimental work in
this direction.


title: On the QCD dipole content of hard photon and gluon probes

abstract:
  A gluon forward jet playing the role of a deep probe in high energy
scattering, we analyze its infinite momentum QCD wave function in terms of
dipole (color-singlet quark-antiquark) configurations using k_T-factorization
properties. The comparison is made with virtual photon quark-antiquark
configurations. Some implications for hard processes with forward jets at Hera
and Tevatron are suggested.


title: A note on the production of photons at RHIC

abstract:
  I study the production of prompt photons in polarized hadronic collisions,
considering different isolation prescriptions. In particular, I focus on the
problem of the measurability of the polarized gluon density in the proton
through isolated-photon data.


title: Dissipative effects in semileptonic B decays

abstract:
  We study the time evolution and decay of the neutral B-meson system using
quantum dynamical semigroups. New, nonstandard terms appear in the expression
of relevant observables; they can be parametrized in terms of six
phenomenological constants. Although very small, these parameters may be
detected in the new generation of dedicated B-meson experiments.


title: The QCD description of diffractive processes

abstract:
  We review the application of perturbative QCD to diffractive processes. We
introduce the two gluon exchange model to describe diffractive qq(bar) and
qq(bar)g production in deep inelastic scattering. We study the triple Regge
limit and briefly consider multiple gluon exchange. We discuss diffractive
vector meson production at HERA both at t = 0 and large |t|. We demonstrate the
non-factorization of diffractive processes at hadron colliders.


title: Radiative corrections to e^+e^- -> WW -> 4 fermions

abstract:
  The structure of the double-pole approximation for the O(alpha) corrections
to e^+e^- -> WW -> 4 fermions is described, and some results are presented.
Moreover, results on full tree-level predictions for $e^+e^- -> WW -> 4
fermions + gamma are given.


title:
Looking for extra-dimensions at the weak scale: experimental search for
  Kaluza-Klein states signatures at the e+e- linear collider

abstract:
  An experimental search for signatures of Kaluza-Klein graviton states at the
500 GeV e+e- linear collider, in which the graviton states are produced in
association with a photon, is presented. The study of the signal extraction is
performed with the help of Monte Carlo simulations


title: Multibaryons with strangeness, charm and bottom

abstract:
  Static properties of multiskyrmions with baryon numbers up to 8 are
calculated, including momenta of inertia and sigma-term. The calculations are
based on the recently suggested SU(2) rational map ansaetze. Minimization with
the help of SU(3) variational minimization program shows that these
configurations become local minima in SU(3) configuration space. The B-number
dependence of the so called flavour moment of inertia of multiskyrmions playing
an important role in the quantization procedure is close to the linear one. The
spectra of baryonic systems with strangeness, charm and bottom are considered
within a "rigid oscillator" version of the bound state soliton model. The
binding energies estimates are made for the states with largest isospin which
can appear as negatively charged nuclear fragments, as well as for states with
zero isospin - light fragments of "flavoured" nuclear matter. Our results
confirm the previously made observation that baryonic systems with charm or
bottom quantum numbers have more chance to be stable with respect to strong
interactions than strange baryonic systems.


title: The Extended Chiral Quark Model confronts QCD

abstract:
  We discuss the truncation of low energy effective action of QCD below the
chiral symmetry breaking (CSB) scale, including all operators of dimensionality
less or equal to 6 which can be built with quark and chiral fields. We perform
its bosonization in the scalar, pseudoscalar, vector and axial-vector channels
in the large-N_c and leading-log approximation. Constraints on the coefficients
of the effective lagrangian are derived from the requirement of Chiral Symmetry
Restoration (CSR) at energies above the CSB scale in the scalar-pseudoscalar
and vector-axial-vector channels, from matching to QCD at intermediate scales,
and by fitting some hadronic observables. In this truncation two types of
pseudoscalar states (massless pions and massive Pi'-mesons), as well as a
scalar, vector and axial-vector one arise as a consequence of dynamical chiral
symmetry breaking. Their masses and coupling constants as well as a number of
chiral structural constants are derived. A reasonable fit of all parameters
supports a relatively heavy scalar meson (quarkonium) with the mass \sim 1 GeV
and a small value of axial pion-quark coupling constant g_A \simeq 0.55.


title:
Pre-resonant Charmonium-Nucleon Cross Section in the Model of the
  Stochastic Vacuum

abstract:
  We calculate the nonperturbative charmonium - nucleon cross sections with the
model of the stochastic vacuum, which has been succesfully applied in many high
energy reactions. We also give a quantitative discussion of pre-resonance
formation and medium effects.


title:
On high $Q^{2}$ behavior of the pion form factor for transitions
  $\gamma^{\ast} \gamma \to \pi^{0}$ and $\gamma ^{\ast} \gamma^{\ast} \to
  \pi^{0}$ within the nonlocal quark-pion model

abstract:
  The behavior of the transition pion form factor for processes \gamma^*\gamma
-> \pi^0 and \gamma^* \gamma^* -> \pi^0 at large values of space-like photon
momenta is estimated within the nonlocal covariant quark-pion model. It is
shown that, in general, the coefficient of the leading asymptotic term depends
dynamically on the ratio of the constituent quark mass and the average
virtuality of quarks in the vacuum and kinematically on the ratio of photon
virtualities. The kinematic dependence of the transition form factor allows us
to obtain the relation between the pion light-cone distribution amplitude and
the quark-pion vertex function. The dynamic dependence indicates that the
transition form factor \gamma^* \gamma -> \pi^0 at high momentum transfers is
very sensitive to the nonlocality size of nonperturbative fluctuations in the
QCD vacuum.


title:
Dynamical Renormalization Group Approach to Quantum Kinetics in Scalar
  and Gauge Theories

abstract:
  We derive quantum kinetic equations from a quantum field theory implementing
a diagrammatic perturbative expansion improved by a resummation via the
dynamical renormalization group. The method begins by obtaining the equation of
motion of the distribution function in perturbation theory. The solution of
this equation of motion reveals secular terms that grow in time, the dynamical
renormalization group resums these secular terms in real time and leads
directly to the quantum kinetic equation. We used this method to study the
relaxation in a cool gas of pions and sigma mesons in the O(4) chiral linear
sigma model. We obtain in relaxation time approximation the pion and sigma
meson relaxation rates. We also find that in large momentum limit emission and
absorption of massless pions result in threshold infrared divergence in sigma
meson relaxation rate and lead to a crossover behavior in relaxation. We then
study the relaxation of charged quasiparticles in scalar electrodynamics
(SQED). While longitudinal, Debye screened photons lead to purely exponential
relaxation, transverse photons, only dynamically screened by Landau damping
lead to anomalous relaxation, thus leading to a crossover between two different
relaxational regimes. We emphasize that infrared divergent damping rates are
indicative of non-exponential relaxation and the dynamical renormalization
group reveals the correct relaxation directly in real time. Finally we also
show that this method provides a natural framework to interpret and resolve the
issue of pinch singularities out of equilibrium and establish a direct
correspondence between pinch singularities and secular terms. We argue that
this method is particularly well suited to study quantum kinetics and transport
in gauge theories.


title:
R-Parity Violating Contributions to Flavor Changing and CP Violation
  Effects in Fermion and Sfermion Pair Production

abstract:
  We examine the contributions from the R-parity odd interactions, $ \l_{ijk}
L_iL_jE_k^c $ and $ \l '_{ijk} L_i Q_j D^c_k$, to the total rates and the CP
asymmetry rates in the production of fermion-antifermion (lepton, down and up
quark) pairs and slepton-antislepton pairs of different flavors at leptonic
colliders. For the top-charm associated production case, we evaluate dynamical
distributions for the semileptonic top decay events and estimate the
sensitivity reach on the relevant parameters.


title: A Quark Model for Heavy Mesons: Strong Decays

abstract:
  I shortly review the application of a recently introduced constituent
quark-meson model to the determination of some strong coupling constants
governing the decays of charm heavy mesons with one pion in the final state. I
present the model directly through its rules for computing amplitudes. For a
detailed explanation of the model, the reader is referred to the original
papers.


title:
Dynamics of Symmetry Breaking Out of Equilibrium: From Condensed Matter
  to QCD and the Early Universe

abstract:
  The dynamics of symmetry breaking during out of equilibrium phase transitions
is a topic of great importance in many disciplines, from condensed matter to
particle physics and early Universe cosmology with definite experimental
impact. In these notes we provide a summary of the relevant aspects of the
dynamics of symmetry breaking in many different fields with emphasis on the
experimental realizations. In condensed matter we address the dynamics of phase
ordering, the emergence of condensates, coarsening and dynamical scaling. In
QCD the possibility of disoriented chiral condensates of pions emerging during
a strongly out of equilibrium phase transition is discussed. We elaborate on
the dynamics of phase ordering in phase transitions in the Early Universe, in
particular the emergence of condensates and scaling in FRW cosmologies. We
mention some experimental efforts in different fields that study this wide
ranging phenomena and offer a quantitative theoretical description both at the
phenomenological level in condensed matter, introducing the scaling hypothesis
as well as at a microscopic level in quantum field theories. The emergence of
semiclassical condensates and a dynamical length scale is shown in detail, in
quantum field theory this length scale is constrained by causality. The large N
limit provides a natural bridge to compare the solutions in different settings
and to establish similarities and differences.


title: A Cosmology of the Brane World

abstract:
  We develop a possible cosmology for a Universe with n additional spatial
dimensions of variable scale, and an associated scalar field, the radion, which
is distinct from the field responsible for inflation, the inflaton. Based on a
particular ansatz for the effective potential for the inflaton and radion
(which may emerge in string theory), we show that the early expansion of the
Universe may proceed in three stages. First, the radion becomes trapped at a
value much smaller than the size of the extra dimensions today. Second, the
Universe expands exponentially, but with a Planck mass smaller than its present
value. Because the Planck mass during inflation is small, density fluctuations
in agreement with observations can arise naturally. Third, when inflation ends,
the Universe reheats, and the radion becomes free to expand once more. During
the third phase the Universe is ``radiation-dominated'' and tends toward a
fixed-point evolutionary model in which the radion grows but the temperature
remains unchanged. Ultimately, the radion becomes trapped once again at its
present value, and a short period of exponential expansion, which we identify
with the electroweak phase transition, ensues. Once this epoch is over, the
Universe reheats to a temperature of order the electroweak scale, and the
mature Universe evolves as in standard cosmological models. We show that the
present day energy density in radions can be smaller than the closure density
if the second inflationary epoch lasts about 8 e-foldings or more; the
present-day radion mass turns out to be small (less than or of the order of an
eV, depending on parameters). We argue that although our model envisages
considerable time evolution in the Planck mass, substantial spatial
fluctuations in Newton's constant are not produced.


title: Pade-Improvement of CP-odd Higgs Decay Rate into Two Gluons

abstract:
  We present an asymptotic Pade-approximant estimate for the four-loop
coefficients within the linear combination of correlators entering the recently
calculated decay rate of a CP-odd Higgs boson, with an assumed mass $m_A = 100
GeV$, into two gluons. All but one of these coefficients are shown to be
determined for arbitrary $m_A$ from the known 3-loop-order rate by
renormalization group methods. Asymptotic Pade-approximant estimates for these
coefficients are all seen to be within 12% of their correct values. The
four-loop term in the decay rate for $m_A = 100 GeV$ is estimated to be only
4.3% of its leading one-loop contribution.


title: Effective Theories for Hot Non-Abelian Dynamics

abstract:
  The dynamics of soft ($|\vec{p}|\sim g^2 T$) non-Abelian gauge fields at
finite temperature is non-perturbative. The effective theory for the soft
fields can be obtained by first integrating out the momentum scale T, which
yields the well known hard thermal loop effective theory. Then the latter is
used to integrate out the scale gT. One obtains a Boltzmann equation, which can
be solved in a leading logarithmic approximation. The resulting effective
theory for the soft fields is described by a Langevin equation, and it is well
suited for non-perturbative lattice simulations.


title: Distinguishing anomaly mediation from gauge mediation with a Wino NLSP

abstract:
  A striking consequence of supersymmetry breaking communicated purely via the
superconformal anomaly is that the gaugino masses are proportional to the gauge
beta functions. This result, however, is not unique to anomaly mediation. We
present examples of ``generalized'' gauge-mediated models with messengers in
standard model representations that give nearly identical predictions for the
gaugino masses, but positive (mass)^2 for all sleptons. There are remarkable
similarities between an anomaly-mediated model with a small additional
universal mass added to all scalars and the gauge-mediated models with a
long-lived Wino next-to-lightest supersymmetric particle (NLSP), leading to
only a small set of observables that provide robust distinguishing criteria.
These include ratios of the heaviest to lightest selectrons, smuons, and stops.
The sign of the gluino soft mass an unambiguous distinction, but requires
measuring a difficult class of one-loop radiative corrections to sparticle
interactions. A high precision measurement of the Higgs-b-\bar{b} coupling is
probably the most promising interaction from which this sign might be
extracted.


title: Seeking TeV-Scale Quantum Gravity at an $e \gamma$ collider

abstract:
  Theories with large extra compact dimensions predict exciting
phenomenological consequences at the TeV scale. Such theories can,
consequently, be tested/verified in experiments at future colliders like the
Next Linear Collider (NLC). In this paper, we study the production of the
spin-2 Kaluza-Klein excitations in NLC operating in the $e \gamma$ mode.
Results for unpolarised and polarised cases are presented and it is shown that
it is possible to use this process to test these theories to values of the
effective string scale between about 1 - 7 TeV.


title: Production and decays of stops, sbottoms, and staus

abstract:
  We present a phenomenological analysis of production and decays of stops,
sbottoms, and staus in e+e- collisions with sqrt(s) = 500 - 800 GeV. We include
SUSY-QCD and Yukawa coupling corrections as well as initial state radiation. We
show that e- beam polarization is a powerful tool for a determination of the
underlying SUSY parameters. Using in addition a polarized e+ beam improves the
precision of the parameter determination by about 25%.


title:
Is there a unique thermal dilepton source in the reactions Pb(158 AGeV)
  + Au, Pb?

abstract:
  An analysis of the dilepton measurements of the reactions Pb(158 A$\cdot$GeV)
+ Au, Pb by the CERES and NA50 collaborations points to a unique thermal source
contributing to the invariant mass and transverse momentum spectra.


title: Oscillations of Cumulant Moments - Universality of Amplitudes

abstract:
  We demonstrate on simple examples that oscillatory behaviour of moments of
multiplicity distributions P(n) observed in e^+e^- annihilations, in hadronic
pp collisions and in collisions on nuclei, p+A, is to a large extend caused by
the experimental artifact of measuring only limited range of P(n). In
particular we show that by applying a suitable universal cutt-off procedure to
the measured P(n) one gets for reactions mentioned before oscillations of
similar magnitude. The location of zeros of oscillations as a function of the
rank of moments and their shapes remain, however, distinctively different for
different types of reactions considered. This applies to some extend also to
collisions of nuclei, which otherwise follow their own pattern of behaviour.


title: Structure functions at small x_Bj in a Euclidean field theory approach

abstract:
  The small-x_Bj limit of deep inelastic scattering is related to the
high-energy limit of the forward Compton amplitude in a familiar way. We show
that the analytic continuation of this amplitude in the energy variable is
calculable from a matrix element in Euclidean field theory. This matrix element
can be written as a Euclidean functional integral in an effective field theory.
Its effective Lagrangian has a simple expression in terms of the original
Lagrangian. The functional integral expression obtained can, at least in
principle, be evaluated using genuinely non-perturbative methods, e.g., on the
lattice. Thus, a fundamentally new approach to the long-standing problem of
structure functions at very small x_Bj seems possible. We give arguments that
the limit x_Bj -> 0 corresponds to a critical point of the effective field
theory where the correlation length becomes infinite in one direction.


title: Domain wall fermions and the strange quark mass

abstract:
  The strange quark mass has been computed using a lattice action which
possesses continuum--like chiral symmetry to good precision, namely the domain
wall fermion action. This talk surveys this action and the recent calculation
of m_s by the RIKEN/BNL/CU collaboration. This result is put into context by
briefly summarizing other recent lattice studies.


title: Probing Strong Electroweak Symmetry Breaking in W+ W- -> t \bar t

abstract:
  We study the process $W^+ W^- \to t \bar t$ in several models of strong
interaction electroweak symmetry breaking. We calculate the signals that can be
expected by observing the reaction $e^+ e^- \to \nu \bar\nu t \bar t$ at an
$e^+ e^-$ linear collider with 1.5 TeV center of mass energy. We also discuss
how the lowest-lying resonances predicted by these models could be identified
using top polarization observables.


title:
Weak Interactions Effect on the P-N Mass Splitting and the Principle of
  Equivalence

abstract:
  The weak interaction contribution to the proton neutron mass difference is
computed using a generalization of Cottingham's formula. When included in the
analysis of the Eotvos experiment, this contribution reduces the bound on a
possible weak interactions violation to the equivalence principle by one order
of magnitude.


title: N->Delta Quadrupole Transition in the Constituent Quark Model

abstract:
  Information on the intrinsic deformation of the proton can be obtained by
studying the electromagnetic p-->Delta+ quadrupole transition. Recent
experiments have shown that the electric quadrupole (E2) strength in gamma p
--> Delta+ is about 10 times larger than predicted by the simple quark model
using only one-body currents. Our analysis provides evidence for the dominance
of exchange currents in the N-->Delta quadrupole transition and identifies the
physical mechanism leading to the observed E2 strength.


title:
Supersymmetric Higgs Boson Pair Production: Discovery Prospects at
  Hadron Colliders

abstract:
  We study the potential of hadron colliders in the search for the pair
production of neutral Higgs bosons in the framework of the Minimal
Supersymmetric Standard Model. We perform a detailed signal and background
analysis, working out efficient kinematical cuts for the extraction of the
signal. The important role of squark loop contributions to the signal is
re--emphasized. If the signal is sufficiently enhanced by these contributions,
it could even be observable at the next run of the upgraded Tevatron collider
in the near future. At the LHC the pair production of light and heavy Higgs
bosons might be detectable simultaneously.


title:
The abundance of moduli, modulini and gravitinos produced by the vacuum
  fluctuation

abstract:
  Moduli, modulini and the gravitino have gravitational-strength interactions,
and thermal collisions after reheating create all of them with roughly the same
abundance. With their mass of order $100\GeV$, corresponding to
gravity-mediated supersymmetry breaking, this leads to the well-known bound
$\gamma T\sub R\lsim 10^9\GeV$ on the reheat temperature, where $\gamma\leq 1$
is the entropy dilution factor. The vacuum fluctuation also creates these
particles, with abundance determined by the solution of the equation for the
mode function. Taking the equation in each case to be the one corresponding to
a free field, we consider carefully the behaviour of the effective mass during
the crucial era after inflation. It may have a rapid oscillation, which does
not however affect the particle abundance. Existing estimates are confirmed;
the abundance of modulini and (probably) of moduli created from the vacuum is
less than from thermal collisions, but the abundance of gravitinos may be much
bigger, leading to a tighter bound on $T\sub R$ if supersymmetry breaking is
gravity-mediated. It is noted that in the case of gauge-mediated supersymmetry
breaking, the abundance of the gravitino may be sufficient to make it a dark
matter candidate.


title:
The Boltzmann equation for gluons at early times after a heavy ion
  collision

abstract:
  A Boltzmann equation is given for the early stages of evolution of the gluon
system produced in a head-on collision. The collision term is taken from gluon-
gluon approximation. < p_\perp > and < p_z^2 > are evaluated as a function of
time using initial conditions taken from the McLerran-Venugopalan model.


title: Breaking Parity Symmetry Using Extra Dimensions

abstract:
  We present a new way to break parity symmetry in left-right symmetric models
using boundary conditions on the fields residing in the fifth dimension. We
also discuss the connection between the limits on the size of extra dimensions
and the scale of right handed symmetry breaking obtained from the analysis of
neutrinoless double beta decay in the case where the righthanded gauge symmetry
is in the bulk.


title:
Can lepton flavor violating interactions explain the atmospheric
  neutrino problem?

abstract:
  We investigate whether flavor changing neutrino interactions (FCNIs) can be
sufficiently large to provide a viable solution to the atmospheric neutrino
problem. Effective operators induced by heavy boson exchange that allow for
flavor changing neutrino scattering off quarks or electrons are related by an
$SU(2)_L$ rotation to operators that induce anomalous tau decays. Since
$SU(2)_L$ violation is small for New Physics at or above the weak scale, one
can use the upper bounds on lepton flavor violating tau decays or on lepton
universality violation to put severe, model-independent bounds on the relevant
non-standard neutrino interactions. Also $Z$-induced flavor changing neutral
currents, due to heavy singlet neutrinos, are too small to be relevant for the
atmospheric neutrino anomaly. We conclude that the FCNI solution to the
atmospheric neutrino problem is ruled out.


title: New Physics Effects in Doubly Cabibbo Suppressed D Decays

abstract:
  The most sensitive experimental searches for $D-\bar D$ mixing use $D^0 \to
K^+ \pi^-$ decays. It is often assumed that effects of New Physics and, in
particular, CP violation, can appear through the mixing, while the $c \to d u
\bar s$ decay amplitude cannot have significant contributions from New Physics
and is, therefore, CP conserving to a good approximation. We examine this
assumption in two ways. First, we calculate the contributions to the decay in
various relevant models of New Physics: Supersymmetry without R-parity,
multi-scalar models, left-right symmetric models, and models with extra quarks.
We find that phenomenological constraints imply that the New Physics
contributions are indeed small compared to the standard model doubly Cabibbo
suppressed amplitude. Second, we show that many of our constraints hold
model-independently. We find, however, one case where the model-independent
bound is rather weak and a CP violating contribution of order 30% is not
excluded.


title:
Graviton Production By Two Photon and Electron-Photon Processes In
  Kaluza-Klein Theories With Large Extra Dimensions

abstract:
  We consider the production of gravitons via two photon and electron-photon
fusion in Kaluza-Klein theories which allow TeV scale gravitational
interactions. We show that at electron-positron colliders, the processes l+l-
-> l+ l- graviton, with l=e, mu, can lead to a new signal of low energy gravity
of the form l+l- -> l+l- + missing energy which is well above the Standard
Model background. For example, with two extra dimensions at the Next Linear
Collider with a center of mass energy of 500 or 1000 GeV, hundreds to thousands
such l+ l- graviton events may be produced if the scale of the gravitational
interactions, M_D, is around a few TeV. At a gamma-electron collider, more
stringent bounds may be placed on M_D via the related reaction e^-\gamma -> e^-
graviton. For instance, if a 1TeV electron positron collider is converted to an
electron-photon collider, a bound of ~10TeV may be placed on the scale M_D if
the number of extra dimensions delta=2 while a bound of ~4TeV may be placed if
delta=4.


title:
Searching for $\nu_\mu \to \nu_\tau$ Oscillations with Extragalactic
  Neutrinos

abstract:
  We propose a novel approach for studying $\nu_\mu \to \nu_\tau$ oscillations
with extragalactic neutrinos. Active Galactic Nuclei and Gamma Ray Bursts are
believed to be sources of ultrahigh energy muon neutrinos. With distances of
100 Mpc or more, they provide an unusually long baseline for possible detection
of $\nu_\mu \to \nu_\tau$ with mixing parameters $\Delta m^2$ down to
$10^{-17}$eV$^2$, many orders of magnitude below the current accelerator
experiments. By solving the coupled transport equations, we show that
high-energy $\nu_\tau$'s, as they propagate through the earth, cascade down in
energy, producing the enhancement of the incoming $\nu_\tau$ flux in the low
energy region, in contrast to the high-energy $\nu_\mu$'s, which get absorbed.
For an AGN quasar model we find the $\nu_\tau$ flux to be a factor of 2 to 2.5
larger than the incoming flux in the energy range between $10^2$ GeV and $10^4$
GeV, while for a GRB fireball model, the enhancement is 10%-27% in the same
energy range and for zero nadir angle. This enhancement decreases with larger
nadir angle, thus providing a novel way to search for $\nu_\tau$ appearance by
measuring the angular dependence of the muons. To illustrate how the cascade
effect and the $\nu_\tau$ final flux depend on the steepness of the incoming
$\nu_\tau$, we show the energy and angular distributions for several generic
cases of the incoming tau neutrino flux, $F_\nu^0 \sim E^{-n}$ for n=1,2 and
3.6. We show that for the incoming flux that is not too steep, the signal for
the appearance of high-energy $\nu_\tau$ is the enhanced production of lower
energy $\mu$ and their distinctive angular dependence, due to the contribution
from the $\tau$ decay into $\mu$ just below the detector.


title: Diffractive production of S and D wave vector mesons in DIS

abstract:
  In this work the production of vector mesons in diffractive DIS is analyzed,
with an emphasis on the impact of the internal spin structure of a vector meson
upon its virtual photoproduction rate. We derived the full sets of s-channel
helicity conserving and violating amplitudes for pure S and D wave vector
mesons and found a striking difference between S and D wave vector meson
production. First, in the case of helicity conserving amplitudes, D wave vector
mesons were found to exhibit dramatically different Q^2-behavior due to
abnormally large higher twist contributions. Besides, we found that helicity
conserving amplitudes for S and D states are numerically comparable, which
makes the physical rho meson very sensitive to D wave admixture. Second, the
helicity violating amplitudes turned out large both for S and D wave states of
light vector mesons and for D wave heavy vector mesons as well.
  Aiming at producing sort of a manual on the diffractive vector meson
production, we carried out all calculations in a pedagogical manner with
maximally full presentation of intermediate steps and accompanied them with
detailed qualitative discussion.


title: Four-Neutrino Mixing

abstract:
  It is shown that at least four massive neutrinos are needed in order to
accommodate the evidences in favor of neutrino oscillations found in solar and
atmospheric neutrino experiments and in the LSND experiment. Among all
four-neutrino schemes, only two 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.