title:
Dynamical Gauge Symmetry Breaking in $SU(3)_L\otimes U(1)_X$ Extension
  of the Standard Model

abstract:
  We study the $SU(3)_L\otimes U(1)_X$ extension of the Standard model with a
strong U(1) coupling. We argue that current experiments limit this coupling to
be relatively large. The model is dynamically broken to the Standard $SU(2)_L
\otimes U(1)$ model at the scale of a few TeV with all the extra gauge bosons
and the exotic quarks acquiring masses much larger than the scale of
electroweak symmetry breaking. Furthermore we find that the model leads to
large dynamical mass of the top quark and hence also breaks the electroweak
gauge symmetry. It therefore leads to large dynamical effects within the
Standard model and can partially replace the Higgs interactions.


title:
b quark Electric Dipole moment in the general two Higgs Doublet and
  three Higgs Doublet models

abstract:
  We study the Electric Dipole moment of b quark in the general two Higgs
Doublet model (model III) and three Higgs Doublet model with O(2) symmetry in
the Higgs sector. We analyse the dependency of this quantity to the new phase
coming from the complex Yukawa couplings and masses of charged and neutral
Higgs bosons. We see that the Electric Dipole moment of b quark is at the order
of 10^{-20} e cm, which is an extremely large value compared to one calculated
in the SM and also two Higgs Doublet model (model II) with real Yukawa
couplings.


title:
Electromagnetic corrections for the analysis of low energy $\pi^- p$
  scattering data

abstract:
  We calculate the electromagnetic corrections to the isospin invariant mixing
angle and to the two eigenphases for the $s$-, $p_{1/2}$- and $p_{3/2}$-partial
waves for $\pi^- p$ elastic and charge exchange scattering. These corrections
have to be applied to the nuclear quantities in order to obtain the two
hadronic phase shifts for each partial wave. The calculation uses relativised
Schr\"{o}dinger equations containing the sum of an electromagnetic potential
and an effective hadronic potential. The mass differences between $\pi^-$ and
$\pi^0$ as well as between $p$ and $n$ are taken into account. We compare our
results with those of previous calculations and qualitatively estimate the
uncertainties in the corrections.


title:
Sneutrino Vacuum Expectation Values and Neutrino Anomalies Through
  Trilinear R-parity Violation

abstract:
  Neutrino mass spectrum is reanalyzed in supersymmetric models with explicit
trilinear $R$ violation. Models in this category are argued to provide
simultaneous solution to the solar and atmospheric neutrino anomalies. It is
shown specifically that large mixing and hierarchical masses needed for the
vacuum solution of neutrino anomalies arise naturally in these models without
requiring any additional symmetries or hierarchies among the trilinear
couplings.


title: Sudakov Resummation Effects in Prompt-Photon Hadroproduction

abstract:
  We compute the effects of soft-gluon resummation, at the
next-to-leading-logarithmic level, in the fixed-target hadroproduction cross
section for prompt photons. We find in general that the corrections to the
fixed next-to-leading-order results are large for large renormalization scales,
and small for small scales. This leads to a significant reduction of the scale
dependence of the results for most experimental configurations of interest. We
compare our results to the recent measurements by the E706 and UA6
collaborations.


title: Comment on ``Mixing and Decay Constants of Pseudoscalar Mesons''

abstract:
  The key assumption used recently by Feldmann, Kroll and Stich [Phys.Rev. D58,
114006 (1998)] that the decay constants f_\eta, and f_\eta ' of the respective
eta and eta ' mesons in the quark flavor basis follow the pattern of strange
and non--strange quarkonia mixing in their wave functions, is reproduced in
identifying the non-isotriplet part of the strong neutral axial current with
the genuine axial hypercharge current J_{\mu, 5}^Y =\bar q \gamma_\mu\gamma_5
Y/2 q, where Y=C+S+B is defined by the Gell-Mann-Nakano-Nishijima relation as
the sum of charm (C), strangeness (S), and baryon (B) quark quantum numbers.
The inequivalence between octet and hypercharge axial currents is pointed out.


title:
Impact-picture predictions for the $\gamma\gamma$ total cross section at
  LEP

abstract:
  We show that the rising total cross section $\sigma(\gamma\gamma \to
hadrons)$ recently observed by the L3 and OPAL Collaborations at LEP are fully
consistent with the impact-picture for high-energy scattering. The impact
picture is then used to predict this total cross section at higher energies.
These experimental results confirm once more the success of the theoretical
approach, which predicted for the first time, nearly thirty years ago, the
universal increase of total cross sections at high energies.


title: Small x QCD effects in DIS with a forward jet or a forward pi0

abstract:
  We compare predictions based on small x (QCD) dynamics with recent data for
deep inelastic events containing forward jets or forward pi0 mesons. We
quantify the effect of imposing the (higher order) consistency condition on the
BFKL equation and study uncertainties inherent in the QCD predictions. We also
estimate the cross-section for the forward production of two jets.


title:
The $bar{d} - \bar{u}$ asymmetry of the proton in a Pion Cloud Model
  approach

abstract:
  We study the $bar{d} - \bar{u}$ asymmetry of the proton in a model approach
in which hadronic fluctuations of the nucleon are generated through gluon
splitting and recombination mechanisms. Within this framework, it is shown that
the \ud asymmetry of the proton is consistently described by including only
nucleon fluctuations to $|\pi N>$ and $|\pi \Delta>$ bound states. Predictions
of the model closely agree with the recent experimental data of the E866/NuSea
Collaboration.


title: Charm in the Nucleon

abstract:
  A next-to-leading order analysis of inelastic electroproduction of charm is
performed using an interpolating scheme which maps smoothly onto massless QCD
evolution at large Q^2 and photon-gluon fusion at small Q^2. In contrast with
earlier analyses, this scheme allows the inclusion of quark and target mass
effects and heavy quark thresholds, as well as possible non-perturbative, or
intrinsic, charm contributions. We find no conclusive evidence in favor of an
intrinsic charm component in the nucleon, although several data points which
disagree with perturbative QCD expectations will need to be checked by future
experiments.


title: A non-local OPE for hard QCD processes near the elastic limit

abstract:
  A leading twist expansion in terms of bilocal operators is proposed for the
structure functions of deeply inelastic scattering near the elastic limit $x
\to 1$, which is also applicable to a range of other hard quasi-elastic
processes. Operators of increasing dimensions contribute to logarithmically
enhanced terms, which are suppressed by corresponding powers of $1-x$. For the
longitudinal structure function in moment $(N)$ space all the logarithmic
contributions of order $\ln^k N/N$ are shown to be resummable in terms of the
anomalous dimension of the leading operator in the expansion.


title: One-channel Roy equations revisited

abstract:
  The Roy equation in the single channel case is a nonlinear, singular integral
equation for the phase shift in the low-energy region. We first investigate the
infinitesimal neighborhood of a given solution, and then present explicit
expressions for amplitudes that satisfy the nonlinear equation exactly. These
amplitudes contain free parameters that render the non-uniqueness of the
solution manifest. They display, however, an unphysical singularity at the
upper end of the interval considered. This singularity disappears and
uniqueness is achieved if one uses analyticity properties of the amplitudes
that are not encoded in the Roy equation.


title: Recovering corrections in the analysis of intermittent data

abstract:
  The analysis of intermittent data is improved. The standard method of
recovering the history of a particle cascade is proved in general not to
reproduce the structure of the true cascade. The recovering corrections to the
standard method are proposed and tested in the framework of multiplicative
cascading models.


title: Towards Phonon-Like Excitations of Instanton Liquid

abstract:
  The phonon-like excitations of (anti)-instanton ($\bar II$) liquid due to
adiabatic variations of vacuum wave functions are studied in this paper. The
kinetic energy term is found and the proper effective Lagrangian for such
excitations is evaluated. The properties of their spectrum, while corresponding
masses are defined by $\Lambda_{QCD}$, are investigated.


title: Leptonic and Semileptonic Decays of Pseudoscalar Mesons

abstract:
  We employ the relativistic constituent quark model to give a unified
description of the leptonic and semileptonic decays of pseudoscalar mesons
(\pi, K, D, D_s, B, B_s). The calculated leptonic decay constants and form
factors are found to be in good agreement with available experimental data and
other approaches. We reproduce the results of spin-flavor symmetry in the heavy
quark limit.


title:
Bounding the penguin effects on determinations of $\alpha$ from
  $B^0(t)\to\pi^+\pi^-$ decays

abstract:
  In the absence of the QCD penguin contributions a measurement of the
time-dependent asymmetry in the decay $B^0(t)\to \pi^+\pi^-$ gives directly the
weak angle $\alpha$. Several bounds have been proposed in the literature on the
magnitude of the penguin effects on this determination, the prototype of which
is the isospin bound of Grossman and Quinn. It is pointed out that large strong
final state interactions could cause these bounds to overestimate the real
penguin effect. A new flavor SU(3) bound is proposed, requiring only the
charge-averaged branching ratios for $B^0\to \pi^+\pi^-$ and $B_s\to K^+K^-$,
which exactly takes into account all relevant amplitudes and electroweak
penguin effects. This bound on the penguin-induced error on the determination
of the weak phase $\alpha$ holds even without a knowledge of the direct CP
asymmetry in the $\pi^+\pi^-$ channel.


title: Sparticle Masses from the Superconformal Anomaly

abstract:
  We discuss a recently proposed scenario where the sparticle masses are purely
mediated by gravity through the superconformal anomaly. This scenario elegantly
evades the supersymmetric flavor problem since soft masses, like the anomaly,
are not directly sensitive to ultraviolet physics. However, its minimal
incarnation fails by predicting tachyonic sleptons. We study the conditions for
decoupling of heavy threshold effects and how these conditions are evaded. We
use these results to build a realistic class of models where the non-decoupling
effects of ultra-heavy vectorlike matter fields eliminate the tachyons. These
models have a flavor invariant superspectrum similar to that of gauge mediated
models. They, however, differ in several aspects: the gaugino masses are not
unified, the colored sparticles are not much heavier than the others, the
mu-problem is less severe and the gravitino mass is well above the weak scale,
m_{3/2} \sim 10 TeV. We also show that in models where an R-symmetry can be
gauged, the associated D-term gives rise to soft terms that are similarly
insensitive to the ultraviolet.


title:
Implications of Precision Electroweak Measurements for Physics Beyond
  the SM

abstract:
  We perform a global analysis of electroweak precision measurements to find
constraints on physics beyond the Standard Model. In particular, we discuss
oblique parameters, which are useful to constrain additional matter fields, as
well as extra $Z$ bosons, and supersymmetry. We also summarize the present
information on the Higgs boson mass.


title:
Gluon Field Strength Correlation Functions within a Constrained
  Instanton Model

abstract:
  We suggest a constrained instanton (CI) solution in the physical QCD vacuum
which is described by large-scale vacuum field fluctuations. This solution
decays exponentially at large distances. It is stable only if the interaction
of the instanton with the background vacuum field is small and additional
constraints are introduced. The CI solution is explicitly constructed in the
ansatz form, and the two-point vacuum correlator of gluon field strengths is
calculated in the framework of the effective instanton vacuum model. At small
distances the results are qualitatively similar to the single instanton (SI)
case, in particular, the form factor $D_{1}$ is small, which is in agreement
with the lattice calculations.


title: Fermi Constants and ``New Physics''

abstract:
  Various precision determinations of the Fermi constant are compared. Included
are muon and (leptonic) tau decays as well as indirect prescriptions employing
$\alpha, m_Z, m_W, \ssthwmzms, \Gamma(Z\to\ell^+\ell^-)$, and $\Gamma(Z \to
\nu\bar \nu)$ as input. Their good agreement tests the standard model at the
$\pm 0.1%$ level and provides stringent constraints on new physics. That
utility is illustrated for: heavy neutrino mixing, 2 Higgs doublet models, S,
T, and U parameters and excited $W^{\ast^\pm}$ bosons (Kaluza-Klein
excitations). For the last of those examples, $m_{W^\ast}\gsims 2.9$ TeV is
found.


title:
Calculability of Quark Mixing Parameters from General Nearest Neighbor
  Interaction Texture Quark Mass Matrices

abstract:
  We perform an analysis of general quark mass matrices in the general nearest
neighbor interaction form. Excellent agreement with experiment is realized with
this general texture, which is neither hermitian nor real-symmetric. We then
propose a new class of quark mass matrices that contain no additional
parameters other than the quark masses themselves, and thus possess
calculability, i.e., ensure a relationship between the six quark masses and
four flavor-mixing parameters of the Standard Model.


title: Charmless Hadronic Two-body Decays of B_u and B_d Mesons

abstract:
  Two-body charmless nonleptonic decays of B_u and B_d mesons are studied
within the framework of generalized factorization in which the effective Wilson
coefficients $c^{eff}_i$ are renormalization-scale and -scheme independent
while factorization is applied to the tree-level hadronic matrix elements.
Contrary to previous studies, our $c_i^{eff}$ do not suffer from gauge and
infrared problems. Nonfactorizable effects are parametrized in terms of N_c(LL)
and N_c(LR), the effective numbers of colors arising from (V-A)(V-A) and
(V-A)(V+A) four-quark operators, respectively. Tree and penguin transitions are
classified into six different classes. The data of $B^-\to\rho^0\pi^-$ and
$B^-\to\phi K^-$ clearly indicate that $N_c(LR)\neq N_c(LL)$: The first
measurement of the b -> u mode $B^-\to\rho^0\pi^-$ and the experimental
information on the tree-dominated mode $B^-\to\omega\pi^-$ all imply that
Nc(LL) is less than 3, whereas the CLEO measurement of $B^-\to\phi K^-$ shows
Nc(LR)>3. For given input parameters, the prediction of ${\cal B}(B\to\eta' K)$
is largely improved by setting Nc(LL)~2 and Nc(LR)>Nc(LL); in particular, the
charm content of the eta' contributes in the right direction. The decay rate of
$B\to\phi K^*$ is very sensitive to the form-factor ratio A_2/A_1; the absence
of $B\to\phi K$ events does not necessarily invalidate the factorization
approach. If the branching ratio of $B^-\to\omega K^-$ is experimentally found
to be significantly larger than that of $B^-\to\rho^0 K^-$, we argue that
inelastic final-state rescattering may account for the disparity between
$\omega K^-$ and $\rho^0 K^-$.


title:
Four-Neutrino Mass Spectra and the Super-Kamiokande Atmospheric Up-Down
  Asymmetry

abstract:
  In the framework of schemes with mixing of four massive neutrinos, which can
accommodate the atmospheric, solar and LSND ranges of Delta m^2, we show that,
in the whole region of Delta m^2_{LSND} allowed by LSND, the Super-Kamiokande
up-down asymmetry excludes all mass spectra with a group of three close
neutrino masses separated from the fourth mass by the LSND gap of order 1 eV.
Only two schemes with mass spectra in which two pairs of close masses are
separated by the LSND gap can describe the Super-Kamiokande up-down asymmetry
and all other existing neutrino oscillation data.


title:
Extracting $\gamma$ from $B_{s(d)}\to J/\psi K_S$ and $B_{d(s)}\to
  D^{+}_{d(s)} D^{-}_{d(s)}$

abstract:
  A completely general parametrization of the time-dependent decay rates of the
modes $B_s\to J/\psi K_S$ and $B_d\to J/\psi K_S$ is given, which are related
to each other through the $U$-spin flavour symmetry of strong interactions.
Owing to the interference of current--current and penguin processes, the
$B_s\to J/\psi K_S$ observables probe the angle $\gamma$ of the unitarity
triangle. Using the $U$-spin symmetry, the overall normalization of the $B_s\to
J/\psi K_S$ rate can be fixed with the help of the CP-averaged $B_d\to J/\psi
K_{\rm S}$ rate, providing a new strategy to determine $\gamma$. This
extraction of $\gamma$ is not affected by any final-state-interaction effects,
and its theoretical accuracy is only limited by $U$-spin-breaking corrections.
As a by-product, this strategy allows us to take into account also the penguin
effects in the determination of $\beta$ from $B_d\to J/\psi K_S$, which are
presumably very small, and to predict the direct CP asymmetry arising in this
mode. An analogous strategy is provided by the time-dependent $B_d\to D^+ D^-$
rate, if its overall normalization is fixed through the CP-averaged $B_s\to
D^+_s D^-_s$ rate.


title:
New Strategies to Extract $\beta$ and $\gamma$ from $B_d\to \pi^+ \pi^-$
  and $B_s\to K^+ K^-$

abstract:
  The decays $B_d\to \pi^+ \pi^-$ and $B_s\to K^+ K^-$ are related to each
other by interchanging all down and strange quarks, i.e. through the $U$-spin
flavour symmetry of strong interactions. A completely general parametrization
of the CP-violating observables of these modes is presented within the
framework of the Standard Model, allowing the determination of the angles
$\beta$ and $\gamma$ of the unitarity triangle. This strategy is affected
neither by penguin contributions nor by any final-state-interaction effects,
and its theoretical accuracy is only limited by $U$-spin-breaking corrections.
If the $B^0_d - \bar{B^0_d}$ mixing phase $2\beta$ is determined separately,
for example with the help of $B_d\to J/\psi K_S$, $\gamma$ can be extracted
with a reduced $U$-spin flavour symmetry input. A variant of this strategy to
determine $\gamma$, which uses $B_d\to\pi^\mp K^\pm$ instead of $B_s\to K^+
K^-$ and relies -- in addition to the SU(3) flavour symmetry -- on a certain
dynamical assumption, is also briefly discussed.


title: Gluon Condensate from Superconvergent QCD Sum Rule

abstract:
  Sum rules for the nonperturbative piece of correlators (specifically, the
vector current correlator) are discussed. The sum rule subtracting the
perturbative part is of the superconvergent type. Thus it is dominated by the
bound states and low energy production cross section. It leads to a
determination of the gluon condensate of $<\alpha_s G^2> = 0.048 \pm 0.039
GeV^4$


title: Direct T-violation measurements and T-odd effects in decay experiments

abstract:
  Motivated by the recent experimental announcements for direct measurements of
time-reversal non-invariance in the neutral kaon system, we make a comparative
discussion of the CPLEAR and KTeV measurements. The most suitable way to
consistently incorporate the mixing, the time evolution and the decays of
kaons, is to describe the neutral kaon system as a system with a non-Hermitean
Hamiltonian. In this framework, the physical (decaying) incoming and outgoing
states are distinct and belong to dual spaces. Moreover, since they are
eigenstates of the full Hamiltonian, they never oscillate. This is directly
manifest in the orthogonality conditions of the physical states, which entirely
determine the evolution of the kaon system. Along these lines we conclude:
CPLEAR studies K0-bar{K0} oscillations, a process where initial and final
states can be reversed, the CPLEAR asymmetry being an effect directly related
to the definition of time-reversal. Conclusively, CPLEAR provides a direct
measurement of T-violation without any assumption either on unitarity or on
CPT-invariance. The KTeV experiment studies in particular the process KL -> pi+
pi- e+ e- where they measure a T-odd effect. However, using unitarity together
with estimates of the final state interactions, it should be possible to
determine whether this effect can be identified with a genuine T-reversal
violation.


title: Measuring the cosmological lepton asymmetry through the CMB anisotropy

abstract:
  A large lepton asymmetry in the Universe is still a viable possibility and
leads to many interesting phenomena such as gauge symmetry nonrestoration at
high temperature. We show that a large lepton asymmetry changes the predicted
cosmic microwave background (CMB) anisotropy and that any degeneracy in the
relic neutrino sea will be measured to a precision of 1% or better when the CMB
anisotropy is measured at the accuracy expected to result from the planned
satellite missions MAP and Planck. In fact, the current measurements already
put an upper limit on the lepton asymmetry of the Universe which is stronger
than the one coming from considerations of primordial nucleosynthesis and
structure formation.


title: Neutrino mixings from a U(2) flavour symmetry

abstract:
  We extend a previously developed description of the flavour parameters in the
charged fermion sector, based on a U(2) flavour symmetry, to include two main
features of the neutrino sector seemingly implied by recent data: a large
mixing angle $\theta_{\mu \tau}$ and a large hierarchy in the neutrino squared
mass differences. A unified description of quark and lepton masses and mixings
emerges. The neatest quantitative predictions are for elements of the unitary
mixing matrix in the lepton sector: |V_{\mu 1}| = |V_{e 3} / V_{\mu 3}| = |V_{e
2} / V_{\tau 3}| = \sqrt{m_e / m_\mu}, which go together with the analogous
relations in the quark sector: |V_{ub} / V_{cb}| = \sqrt{m_u / m_c}, |V_{td} /
V_{ts}| = \sqrt{m_d / m_s}


title: Flavor Changing Decays of $\Upsilon$ and $J/\psi$

abstract:
  We study flavor changing processes $\Upsilon \to B/{\bar B} X_s$ and $J/\psi
\to D/{\bar D} X_u$ in the B factories and the Tau-Charm factories. In the
standard model, these processes are predicted to be unobservable, so they serve
as a probe of the new physics. We first perform a model independent analysis,
then examine the predictions of models; such as top color models and MSSM with
R-parity violation ; for the branching ratios of $\Upsilon \to B/{\bar B} X_s$
and $J/\psi \to D/{\bar D} X_u$ . We find that these branching ratios could be
as large as $10^{-6}$ and $10^{-5}$ in the presence of new physics.


title:
Collision Terms from Fluctuations in the HTL Theory for the Quark-Gluon
  Plasma

abstract:
  Starting from the kinetic formulation of the hard thermal loop effective
theory, we have (re)derived the collision terms for soft modes of order $g^2 T
\log(1/g)$ by averaging the statistical fluctuations in the plasma.


title: Searching for VV -> H -> tau tau at the CERN LHC

abstract:
  The production of a neutral, CP even Higgs via weak boson fusion and decay H
-> tau tau at the LHC is studied for the Standard Model and MSSM, utilizing a
parton level Monte Carlo analysis. This channel allows a 5 sigma observation of
a Standard Model Higgs with an integrated luminosity of about 30 fb^-1, and
provides a direct measurement of the H-tau-tau coupling. For the MSSM case, a
highly significant signal for at least one of the Higgs bosons with reasonable
luminosity is possible over the entire physical parameter space which will be
left unexplored by LEP2.


title:
Day-Night and Energy Dependence of MSW Solar Neutrinos for Maximal
  Mixing

abstract:
  It has been stated in the literature that the case of maximal mixing angle
for \nu_e leads to no day-night effect for solar neutrinos and an energy
independent flux suppression of 1/2. While the case of maximal mixing angle and
\Delta m^2 in the MSW range does lead to suppression of the electron neutrinos
reaching the earth from the sun by P_S=1/2, the situation is different for
neutrinos that have passed through the earth. We make the pedagogical point
that, just as with smaller mixing angles, the earth regenerates the |\nu_1>
state from the predominantly |\nu_2 > state reaching the earth, leading to
coherent interference effects. This regeneration can lead to a day-night effect
and an energy dependence of the suppression of solar electron neutrinos, even
for the case of maximal mixing. For large mixing angles, the energy dependence
of the day-night asymmetry depends heavily on Delta m^2. With a sufficiently
sensitive measurement of the day-night effect, this energy dependence could be
used to distinguish among the large mixing angle solutions of the solar
neutrino problem.


title: Neutrino Oscillations and R-parity Violating Collider Signals

abstract:
  R-parity and L violation in the MSSM would be the origin of the neutrino
oscillation observed in Super-Kamiokande. A distinctive feature of this
framework is that it can be tested in colliders by observing decay products of
the destabilized LSP. We examine all the possible decay processes of the
neutralino LSP assuming the bilinear contribution to neutrino masses dominates
over the trilinear one which gives rise to the solar neutrino mass. We find
that it is possible to probe neutrino oscillations through colliders in most of
the R-parity conserving MSSM parameter space.


title:
Dynamical evolution of the Universe in the quark-hadron phase transition
  and possible nugget formation

abstract:
  We study the dynamics of first-order phase transition in the early Universe
when it was $10-50 \mu s$ old with quarks and gluons condensing into hadrons.
We look at how the Universe evolved through the phase transition in small as
well as large super cooling scenario, specifically exploring the formation of
quark nuggets and their possible survival. The nucleation of the hadron phase
introduces new distance scales in the Universe, which we estimate along with
the hadron fraction, temperature, nucleation time etc. It is of interest to
explore whether there is a relic signature of this transition in the form of
quark nuggets which might be identified with the recently observed dark objects
in our galactic halo and account for the Dark Matter in the Universe at
present.


title: Non-Baryonic Dark Matter -- A Theoretical Perspective

abstract:
  I review axions, neutralinos, axinos, gravitinos and super-massive Wimpzillas
as dark matter candidates.


title: WIMP Velocity Impact on Direct Dark Matter Searches

abstract:
  We examine the effect of some uncertainties in the input astrophysical
parameters on direct detection searches for WIMPs in the Galactic halo. We
concentrate on the possible WIMP annual modulation signal recently reported by
the DAMA Collaboration. We find that allowing for a reasonable uncertainty in a
WIMP Maxwellian velocity distribution leads to significantly relaxed
constraints on the WIMP mass as compared to the original DAMA analysis.


title: Applications of the Light Cone Condition for various perturbed Vacua

abstract:
  We examine the propagation of light in the presence of various modifications
of the QED vacuum in the limit of low frequency. A polarization summed and
direction averaged-light cone condition is derived from the equation of motion
which arises from the effective QED action. Several applications are given
concerning vacuum modifications caused by, e.g., strong fields, Casimir systems
and finite temperature.


title:
Probing the parton densities of virtual photons with the reaction
  gamma^*gamma->jets at LEP

abstract:
  We present a next-to-leading order calculation of jet production in
gamma^*gamma collisions from e+e- scattering in a region where the virtuality
Q^2 of the probing virtual photon is small compared to the transverse jet
energy. The calculation is based on the phase-space slicing method. The initial
state singularity of the virtual photon is factorized into the structure
function of the virtual photon, using the MS-bar factorization scheme for
virtual photons. Numerical results are presented for LEP2 conditions. The
perturbative stability of the pure direct virtual photon approach is compared
to that of including resolved virtual photons in different regions of Q^2. We
make predictions for cross sections which suggest that different
parametrizations of virtual photon parton densities should be distinguishable
by measurements of jet cross sections at LEP.


title:
$\gamma\gamma \to t\bar{c}+c\bar{t}$ in a supersymmetric theory with an
  explicit R-parity violation

abstract:
  We studied the process $\gamma\gamma \to t\bar{c}+c\bar{t}$ in a $R_{p}$
violating supersymmetric Model with the effects from both B- and L-violating
interactions. The calculation shows that it is possible to detect a $R_{p}$
violating signal at the Next Linear Collider. Information about the B-violating
interaction in this model could be obtained under very clean background, if we
take the present upper bounds for the parameters in the supersymmetric $\rlap/
R_{p}$ interactions. Even if we can not detect a signal of $\rlap/R_{p}$ in the
experiment, we may get more stringent constraints on the heavy-flavor
$\rlap/R_{p}$ couplings.


title: Particle Physics from Stars

abstract:
  Low-mass particles such as neutrinos, axions, other Nambu-Goldstone bosons
and gravitons are produced in the hot and dense interior of stars. Therefore,
astrophysical arguments constrain the properties of these particles in ways
which are often complementary to cosmological arguments and to laboratory
experiments. This review provides an update on the most important
stellar-evolution limits and discusses them in the context of other information
from cosmology and laboratory experiments.


title: Seasonal Dependence in the Solar Neutrino Flux

abstract:
  MSW solutions of the solar neutrino problem predict a seasonal dependence of
the zenith angle distribution of the event rates, due to the non-zero latitude
at the Super-Kamiokande site. We calculate this seasonal dependence and compare
it with the expectations in the no-oscillation case as well as just-so
scenario, in the light of the latest Super-Kamiokande 708-day data. The
seasonal dependence can be sizeable in the large mixing angle MSW solution and
would be correlated with the day-night effect. This may be used to discriminate
between MSW and just-so scenarios and should be taken into account in refined
fits of the data.


title:
Top-Quark Phenomenology in Models with Bilinearly and Spontaneously
  Broken R-parity

abstract:
  We study unconventional decays of the top-quark in the framework of SUSY
models with spontaneously broken R-parity. In particular we discuss an
effective theory which consists of the MSSM plus bilinearly broken R-parity. We
demonstrate that the decay modes t -> stau + b and t -> tau + sbottom can have
large branching ratios even in scenarios where the tau-neutrino mass is very
small. We show that existing Tevatron data already probe the theoretical
parameters, with promising prospects for further improvement at the Run 2 of
the Tevatron.


title: Using Scalars to Probe Theories of Low Scale Quantum Gravity

abstract:
  Arkani-Hamed, Dimopoulos and Dvali have recently suggested that gravity may
become strong at energies near 1 TeV which would remove the hierarchy problem.
Such a scenario can be tested at present and future colliders since the
exchange of towers of Kaluza-Klein gravitons leads to a set of new dimension-8
operators that can play important phenomenological roles. In this paper we
examine how the production of pairs of scalars at $e^+e^-$, $\gamma \gamma$ and
hadron colliders can be used to further probe the effects of graviton tower
exchange. In particular we examine the tree-level production of pairs of
identical Higgs fields which occurs only at the loop level in both the Standard
Model and its extension to the Minimal Supersymmetric Standard Model. Cross
sections for such processes are found to be potentially large at the LHC and
the next generation of linear colliders. For the $\gamma\gamma$ case the role
of polarization in improving sensitivity to graviton exchange is emphasized.


title: Constraints on Extended Neutral Gauge Structures

abstract:
  Indirect precision data are used to constrain the masses of possible extra
Z^prime bosons and their mixings with the ordinary Z. We study a variety of
Z^prime bosons as they appear in E_6 and left-right unification models, the
sequential Z boson, and the example of an additional U(1) in a concrete model
from heterotic string theory. In all cases the mixings are severely constrained
(sin theta < 0.01). The lower mass limits are generally of the order of several
hundred GeV and competitive with collider bounds. The exception is the Z_psi
boson, whose vector couplings vanish and whose limits are weaker. The results
change little when the rho parameter is allowed, which corresponds to a
completely arbitrary Higgs sector. On the other hand, in specific models with
minimal Higgs structures the limits are generally pushed into the TeV region.


title: Final state interaction phase in B decays

abstract:
  From an estimate of the meson-meson inelastic scatterin at 5 GeV it is
concluded that a typical strong phase in B decays to two mesons is of order of
20 degrees. For a particular final state an estimate of the phase depends on
whether that state is more or less probable as a final state compared to those
states to which it is connected by the strong interaction S matrix.


title: Diagrammatic approach to soft non-Abelian dynamics at high temperature

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 scale
is determined by diagrams with external momenta $p_0\lsim g^2 T$,
$|\vec{p}|\sim g^2 T$ and loop momenta larger than $g^2 T$. We consider the
polarization tensor beyond the hard thermal loop approximation, which accounts
for loop momenta of order $T$. There are higher loop diagrams, involving also
the scale $gT$, which are as important as the hard thermal loops. These higher
loop contributions are characteristic for non-Abelian gauge theories and their
calculation is simplified by using the hard thermal loop effective theory.
Remarkably, the effective one-loop polarization tensor is found to be gauge
fixing independent and transverse at leading order in $g$. The transversality
indicates that this approach leads to a gauge invariant effective theory.


title: Unification with Enlarged Kaluza-Klein Dimensions

abstract:
  In minimal theories with extra spatial dimensions at scales mu_0 much lower
than the conventional GUT scale, unification can give too-large predictions for
alpha_3(M_Z) given alpha_1(M_Z) and alpha_2(M_Z) as empirical input. We
systematically study the effects of adding extra states above the
compactification scale on running of the gauge couplings and find several
simple examples that give unification where all alpha_i(M_Z) are consistent
with low-energy data. We study both the supersymmetric and nonsupersymmetric
unification.


title: Determining V(ub) from B+ --> D*+(s) e+ e- and B+ --> D*+ e+ e-

abstract:
  It was recently pointed out that the decays B^+ --> D^{*+}_s gamma and B^+
--> D^{*+} gamma can be used for an extraction of |V_{ub}|. The theory of these
decays is poorly understood. It was shown that in a world of almost degenerate
b and c-quarks the decay would be computable. The severe difficulties that are
encountered in the realistic calculation stem primarily from the very hard
photon produced in the two body decay. We point out that in the decays B^+ -->
D^{*+}_s e^+e^- and B^+ --> D^{*+} e^+e^- the photon vertex is soft when the
charmed meson is nearly at rest (in the B^+ rest frame). This allows us to
compute with some confidence the decay rate in a restricted but interesting
kinematic regime. Given enough data the extraction of V_{ub} with reasonably
small uncertainties could proceed through an analysis of these exclusive decays
much as is done in the determination of V_{cb}.


title:
Matter effects in long baseline experiments, the flavor content of the
  heaviest (or lightest) neutrino and the sign of Delta m^2

abstract:
  The neutrinos of long baseline beams travel inside the Earth's crust where
the density is approximately rho = 2.8 g cm^-3. If electron neutrinos
participate in the oscillations, matter effects will modify the oscillation
probabilities with respect to the vacuum case. Depending on the sign of Delta
m^2 an MSW resonance will exist for neutrinos or anti-neutrinos with energy
approximately E_nu(res) = 4.7 |\Delta m^2|/(10^-3 eV^2) GeV. For Delta m^2 in
the interval indicated by the Super-Kamiokande experiment this energy range is
important for the proposed long baseline experiments.
  For positive Delta m^2 the most important effects of matter are a 9% (25%)
enhancement of the transition probability P(nu_mu -> nu_e) for the KEK to
Kamioka (Fermilab to Minos and CERN to Gran Sasso) beam(s) in the energy region
where the probability has its first maximum, and an approximately equal
suppression of P(antinu_mu -> antinu_e). For negative Delta m^2 the effects for
neutrinos and anti-neutrinos are interchanged. Producing beams of neutrinos and
antineutrinos and measuring the oscillation probabilities for both (nu_mu ->
nu_e) and (antinu_mu -> antinu_e) transitions can solve the sign ambiguity in
the determination of Delta m^2.


title: Applications of the Reduction of Couplings

abstract:
  Applications of the principle of reduction of couplings to the standard model
and supersymmetric grand unified theories are reviewed. Phenomenological
applications of renormalization group invariant sum rules for soft
supersymmetry-breaking parameters are also reviewed.


title:
Is there evidence for dimension-two corrections in QCD two-point
  functions?

abstract:
  The ALEPH data on the (non-strange) vector and axial-vector spectral
functions, extracted from tau-lepton decays, is used in order to search for
evidence for a dimension-two contribution, $C_{2 V,A}$, to the Operator Product
Expansion (other than $d=2$ quark mass terms). This is done by means of a
dimension-two Finite Energy Sum Rule, which relates QCD to the experimental
hadronic information. The average $C_{2} \equiv (C_{2V} + C_{2A})/2$ is
remarkably stable against variations in the continuum threshold, but depends
rather strongly on $\Lambda_{QCD}$. Given the current wide spread in the values
of $\Lambda_{QCD}$, as extracted from different experiments, we would
conservatively conclude from our analysis that $C_{2}$ is consistent with zero.


title:
Prediction of the CP violation in the Phenomenological Quark-Lepton Mass
  Matrix Approach

abstract:
  We explore the phenomenological quark-lepton mass matrices, which are devised
following the S$_3$ flavour symmetry principle, yet fully consistent with SU(5)
gauge models with the Higgs particles of {\bf 5}, {\bf 45} and their
conjugates. The model contains 10 free parameters altogether. When 6 parameters
are fixed by charge 2/3 quark and charged lepton masses, charge($-$1/3) quark
masses and all quark mixing matrix elements are predicted to be close to
experiment, leaving some narrow ranges still as freedom. Further specification
of 3 more parameters (using, $m_d$, Cabibbo angle and $|V_{cb}|$) suffices to
fix the quark mixing matrix nearly completely, and all elements come out to be
in accurate agreement with experiment. We obtain the CP violation phase as a
prediction.


title: $\pi - \pi$ Scattering Lengths and Chiral Condensate in NJL Model

abstract:
  Within the general framework of SU(2) Nambu-Jona-Lasinio model beyond
mean-field approximation, the S-wave $\pi - \pi$ scattering lengths $a_0^0$ and
$a_0^2$ are calculated. The numerical results are in agreement with that
analyzed from recent experiment $\pi N \to \pi \pi N$ data by using
Chew-Low-Goebel technique, and the corresponding chiral condensate $<{\bar
q}q>$ is around $-(250 {\rm MeV})^3$, which is close to the ones obtained from
lattice and sum rules.


title: Non-perturbative aspects of hot QCD

abstract:
  I discuss some non-perturbative aspects of hot gauge theories as related to
the unscreened static magnetic interactions. I first review some of the
infrared divergences which cause the breakdown of the perturbation theory. Then
I show that kinetic theory, as derived from quantum field theory, is a powerful
tool to construct effective theories for the soft modes, which then can be
treated non-perturbatively. The effective theory at the scale $gT$ follows from
a collisionless kinetic equation, of the Vlasov type. The effective theory at
the scale $g^2T$ is generated by a Boltzmann equation which includes the
collision term for colour relaxation.


title:
Can LSND and SuperKamiokande be explained by radiative decays of
  muons-neutrinos?

abstract:
  The radiative decay of muon-neutrinos in matter with a scheme of
mass-degenerate neutrinos could be the common origin of the appearance of
anti-electron-neutrinos at LSND and the disappearance of muons-neutrinos at
SuperKamiokande. With the decay probability fixed by the LSND signal, the
deficit of atmospheric neutrinos can be satisfactorily reproduced.


title: On the extraction of skewed parton distributions from experiment

abstract:
  In this paper we will discuss algorithms for extracting skewed parton
distributions from experiment as well as the relevant process and experimental
observable suitable for the extraction procedure.


title:
Proof of factorization for electroproduction of multiple mesons and
  exclusive $\gamma^* \gamma$ production of multiple hadrons

abstract:
  In the following, we will present a generalization of the proof of
factorization for electroproduction of vector mesons to the production of
several mesons such as $\pi^+\pi^-$ and a proof of factorization for exclusive
$\gamma^* \gamma$ production of several hadrons for example $p \bar p$ or
$\pi^+\pi^-$ to all orders in perturbation theory up to power suppressed terms.


title:
Effects of R-parity violation on direct CP violation in B decays and
  extraction of $\gamma$

abstract:
  In the standard model, direct CP-violating asymmetries for $B^\pm \to \pi^\pm
K$ are roughly 2% based on perturbative calculation. Rescattering effects might
enhance it to at most (20-25)%. We show that lepton-number-violating couplings
in supersymmetric models without R-parity are capable of inducing as large as
100% CP asymmetry in this channel. Such effects drastically modify the allowed
range of the CKM parameter $\gamma$ arising from the combinations of the
observed charged and neutral B decays in the $\pi K$ modes. With a multichannel
analysis in B decays, one can either discover this exciting new physics, or
significantly improve the existing constraints on it.


title:
Proposal to look for an up/down asymmetry in atmospheric neutrinos
  beyond Multi-GeV region with existing experimental data

abstract:
  We discuss a possible test of neutrino oscillation hypothesis by proposing
the combined analysis of high energy atmospheric neutrino induced muon events
that have been detected around horizontal direction in the Kolar Gold Field
(KGF) underground site and below the horizontal direction by many large
detectors such as Super-Kamiokande and MACRO. Up/down asymmetry obtained using
contained events recorded by detectors at Kamioka site probes low energy region
of atmospheric neutrino whereas, the suggested method probes high energy
neutrinos. It mainly depends on the observations and it is free of
uncertainties in neutrino flux, interaction cross section etc. In this paper we
demonstrate that the method is sensitive to a region of oscillation parameter
space that explains all the features of atmospheric neutrino data in the
Super-Kamiokande detector; the limiting factor being the statistical strength
of the KGF observations. This method provides the only way to study the up/down
asymmetry beyond Multi-GeV region which is yet to be measured experimentally.


title: F-term inflation in Superstring Theories

abstract:
  A supersymmetric inflationary stage dominated by an $F$-term has the problem
that the flatness of the potential is spoiled by supergravity corrections, that
is the slow-roll parameter $\eta$ gets contributions of order unity. We show
that in $F$-term inflationary models based on strings there is natural way of
obtaining small values of $\eta$. This happens in models of hybrid inflation
based on orbifold constructions, in which a modulus $T$ field is responsible
for the large value of the potential during inflation, and a second field
$\phi$ with appropriate modular weight is responsible for the roll-over. We
illustrate the mechanism with a model in which the inflaton potential is
provided by gaugino condensation, leading to succesful inflation.


title: Soft Contributions to Hard Pion Photoproduction

abstract:
  Hard, or high transverse momentum, pion photoproduction can be a tool for
probing the parton structure of the beam and target. We estimate the soft
contributions to this process, with an eye toward delineating the region where
perturbatively calculable processes dominate. Our soft process estimate is
based on vector meson dominance and data based parameterizations of
semiexclusive hadronic cross sections. We find that soft processes dominate in
single pion photoproduction somewhat past 2 GeV transverse momentum at a few
times 10 GeV incoming energy. The recent polarization asymmetry data is
consistent with the perturbative asymmetry being diluted by polarization
insensitive soft processes. Determining the polarized gluon distribution using
hard pion photoproduction appears feasible with a few hundred GeV incoming
energy (in the target rest frame).


title: Higgs Prospects at the Upgraded Tevatron: Fermilab Study Results

abstract:
  Preliminary results from a Fermilab study of the sensitivity for higgs
production at the Tevatron in run II and beyond are presented. The study
extends existing results by systematically combining all decay channels,
considering the production of higher mass higgs bosons and interpreting the
results in the context of supersymmetric higgs production as well as standard
model production. In addition new analysis methods which significantly improve
sensisity are used.


title: Long-Range Forces of QCD

abstract:
  We consider the scattering of two color dipoles (e.g., heavy quarkonium
states) at low energy - a QCD analog of Van der Waals interaction. Even though
the couplings of the dipoles to the gluon field can be described in
perturbation theory, which leads to the potential proportional to
(N_c^2-1)/R^{7}, at large distances R the interaction becomes totally
non-perturbative. Low-energy QCD theorems are used to evaluate the leading
long-distance contribution \sim (N_f^2-1)/(11N_c - 2N_f)^2 R^{-5/2} exp(-2 \mu
R) (\mu is the Goldstone boson mass), which is shown to arise from the
correlated two-boson exchange. The sum rule which relates the overall strength
of the interaction to the energy density of QCD vacuum is derived.
Surprisingly, we find that when the size of the dipoles shrinks to zero (the
heavy quark limit in the case of quarkonia), the non-perturbative part of the
interaction vanishes more slowly than the perturbative part as a consequence of
scale anomaly. As an application, we evaluate elastic \pi J/\psi and \pi J/\psi
\to \pi \psi' cross sections.


title:
Light-Front Quark Model Analysis of Exclusive $0^{-}$$\to$$0^{-}$
  Semileptonic Heavy Meson Decays

abstract:
  We present the analysis of exclusive $0^{-}$$\to$$0^{-}$ semileptonic heavy
meson decays using the constituent quark model based on the light-front
quantization. Our model is constrained by the variational principle for the
well-known linear plus Coulomb interaction motivated by QCD. Our method of
analytic continuation to obtain the weak form factors avoids the difficulty
associated with the contribution from the nonvalence quark-antiquark pair
creation. Our numerical results for the heavy-to-heavy and heavy-to-light meson
decays are in a good agreement with the available experimental data and the
lattice QCD results. In addition, our model predicts the two unmeasured mass
spectra of $^{1}S_{0}(b\bar{b})$ and $^{3}S_{1}(b\bar{s})$ systems as
$M_{b\bar{b}}$=9657 MeV and $M_{b\bar{s}}$= 5424 MeV.


title: Light Dirac Neutrinos In An $SU(2)_L\times U(1)_Y$ Model

abstract:
  Light Dirac neutrino of mass of mass of the order of few eV is obtained in an
$SU(2)_L\times U(1)_Y$ model with an extended Higgs sector and right-handed
neutrinos. Small neutrino mass is generated at the tree level through small
effective coupling of the Dirac neutrino mass term due to soft discrete
symmetry breaking. In order to remove the exact degeneracy in mass between the
second and the third generation of neutrinos, one loop corrected mass terms are
incorporated. The model can accommodate bi-maximal mixing scenario of neutrino
which has been favoured by recent Solar and atmospheric neutrino experiments.


title:
O(alpha_s^2) Corrections to e+e- to ttbar Total and Differential Cross
  Sections Near Threshold

abstract:
  Recently full O(alpha_s^2, alpha_s*beta, beta^2) corrections to the threshold
total cross section for e+e- to ttbar have been calculated, and the reported
corrections turned out to be unexpectedly large. We study how to reduce
theoretical uncertainties of the cross section. We adopt a new mass definition
proposed by Beneke, which incorporates a renormalon-pole cancellation in the
total energy of a static quark-antiquark pair. This improves the convergence of
the 1S resonance mass, while the normalization of the cross section scarcely
changes. We argue that resummations of logarithms are indispensable, since two
largely separated scales dictate the shape of the cross section. As a first
step, we resum logarithms in the Coulombic part of the t-tbar potential and
observe a considerable improvement in the convergence of corresponding
corrections. There still remain, however, large corrections, which arise from a
1/r^2 term in the ttbar potential. We also calculate full O(alpha_s^2,
alpha_s*beta, beta^2) corrections to the momentum distributions of top quarks
in the threshold region. Corrections to the distribution shape are small on the
1S resonance. At higher energies, corrections become larger.


title:
Nearly Degenerate Neutrino Masses and Nearly Decoupled Neutrino
  Oscillations

abstract:
  We introduce a simple flavor symmetry breaking scheme, in which charged
lepton masses have a strong hierarchy and neutrino masses are almost
degenerate. It is possible to obtain a natural suppression of lepton flavor
mixing between the 1st and 3rd families as well as the approximate decoupling
of atmospheric and solar neutrino oscillations with nearly bi-maximal mixing
factors. The similarity and difference between lepton and quark flavor mixing
schemes are briefly discussed.


title: Avenues for Dynamical Symmetry Breaking

abstract:
  In this talk I review modern theories of dynamical electroweak symmetry
breaking and some of their signatures at Run II of the Tevatron collider.


title:
Extending the DAMA annual-modulation region by inclusion of the
  uncertainties in the astrophysical velocities

abstract:
  The original annual-modulation region, singled out by the DAMA/NaI experiment
for direct detection of WIMPs, is extended by taking into account the
uncertainties in the galactic astrophysical velocities. Also the effect due to
a possible bulk rotation for the dark matter halo is considered. We find that
the range for the WIMP mass becomes 30 GeV < m_chi < 130 GeV at 1-sigma C.L.
with a further extension in the upper bound, when a possible bulk rotation of
the dark matter halo is taken into account. We show that the DAMA results, when
interpreted in the framework of the Minimal Supersymmetric extension of the
Standard Model, are consistent with a relic neutralino as a dominant component
of cold dark matter (on the average in our universe and in our galactic halo).
It is also discussed the discovery potential for the relevant supersymmetric
configurations at accelerators of present generation.


title: Unlocking Color and Flavor in Superconducting Strange Quark Matter

abstract:
  We explore the phase diagram of strongly interacting matter with massless u
and d quarks as a function of the strange quark mass m_s and the chemical
potential mu for baryon number. Neglecting electromagnetism, we describe the
different baryonic and quark matter phases at zero temperature. For quark
matter, we support our model-independent arguments with a quantitative analysis
of a model which uses a four-fermion interaction abstracted from single-gluon
exchange. For any finite m_s, at sufficiently large mu we find quark matter in
a color-flavor locked state which leaves a global vector-like SU(2)_{color+L+R}
symmetry unbroken. As a consequence, chiral symmetry is always broken in
sufficiently dense quark matter. As the density is reduced, for sufficiently
large m_s we observe a first order transition from the color-flavor locked
phase to a color superconducting phase analogous to that in two flavor QCD. At
this unlocking transition chiral symmetry is restored. For realistic values of
m_s our analysis indicates that chiral symmetry breaking may be present for all
densities down to those characteristic of baryonic matter. This supports the
idea that quark matter and baryonic matter may be continuously connected in
nature. We map the gaps at the quark Fermi surfaces in the high density
color-flavor locked phase onto gaps at the baryon Fermi surfaces at low
densities.


title: Quark Description of Hadronic Phases

abstract:
  We extend our proposal that major universality classes of hadronic matter can
be understood, and in favorable cases calculated, directly in the microscopic
quark variables, to allow for splitting between strange and light quark masses.
A surprisingly simple but apparently viable picture emerges, featuring
essentially three phases, distinguished by whether strangeness is conserved
(standard nuclear matter), conserved modulo two (hypernuclear matter), or
locked to color (color flavor locking). These are separated by sharp phase
transitions. There is also, potentially, a quark phase matching hadronic
K-condensation. The smallness of the secondary gap in two-flavor color
superconductivity corresponds to the disparity between the primary dynamical
energy scales of QCD and the much smaller energy scales of nuclear physics.


title: Precision Analysis of the Masses of the Neutral Higgs Bosons in the MSSM

abstract:
  The masses of the neutral CP-even Higgs bosons in the Minimal Supersymmetric
Standard Model (MSSM) are predicted on the basis of explicit
Feynman-diagrammatic calculations. The results, containing the complete
diagrammatic one-loop corrections, the leading two-loop corrections of O(alpha
alpha_s) and further improvements taking into account leading electroweak
two-loop and higher-order QCD contributions, are discussed and compared with
results obtained by renormalization group calculations. Good agreement is found
in the case of vanishing mixing in the scalar top sector, while sizable
deviations occur if scalar top mixing is taken into account. By means of a
Taylor expansion a compact approximation formula for the mass of the lightest
Higgs boson, m_h, is derived. The quality of the approximation in comparison
with the full result is analyzed.


title: Generation of Neutrino Masses and Mixings in Gauge Theories

abstract:
  I review models which present large flavor mixings of the lepton sector based
on the gauge theory.


title: Neutrino Mass and Osciallation: An Introductory Review

abstract:
  After a brief introduction to neutrino mass via the see-saw model I discuss
neutrino mixing and oscillation, first in vacuum and then its matter
enhancement. Then the solar and atmospheric neutrino oscillation data are
briefly reviewed. Finally I discuss the problem of reconciling hierarchical
neutrino masses with at least one large mixing, as implied by these data. A
minimal see-saw model for reconciling the two is discussed.


title:
Renormalization Group Improved Heavy Quark Production in Polarized
  \gamma \gamma Collisions

abstract:
  The experimental determination of the partial width $\Gamma (H
\longrightarrow \gamma \gamma)$ of an intermediate mass Higgs is among the most
important measurements at a future photon photon collider. Recently it was
shown that large non-Sudakov as well as Sudakov double logarithmic (DL)
corrections can be summed to all orders in the background process $\gamma
\gamma (J_z=0) \longrightarrow q \bar{q}$. It was found that positivity and
stability of the cross section was only restored at the four-loop level. One
remaining large source of uncertainty stems from the fact that the scale of the
strong coupling is unspecified within the double logarithmic approximation. In
this paper we include the leading and next-to-leading order running coupling to
all orders. We thus remove the inherent scale uncertainty of both the exact
one-loop and all-orders DL result without encountering any Landau-pole
singularities. The effect is significant and, for the non-Sudakov form factor,
is found to correspond to an effective scale of roughly $\alpha_s(9m_q^2)$.


title:
Nuclear effects in $g_{1A}(x,Q^2)$ at small $x$ in deep inelastic
  scattering on $^7$Li and $^3$He

abstract:
  We suggest to use polarized nuclear targets of $^7$Li and $^3$He to study
nuclear effects in the spin dependent structure functions $g_{1A}(x,Q^2)$.
These effects are expected to be enhanced by a factor of two as compared to the
unpolarized targets.
  We predict a significant $x$ dependence at $10^{-4} \div 10^{-3} \leq x \leq
0.2$ of $g_{1A}(x,Q^2)/g_{1N}(x,Q^2)$ due to nuclear shadowing and nuclear
enhancement. The effect of nuclear shadowing at $x \approx 10^{-3}$ is of an
order of 16% for $g_{1A=7}^{n.s. 3/2}(x,Q^2)/g_{1N}^{n.s.}(x,Q^2)$ and 10% for
$g_{1A=3}^{n.s}(x,Q^2)/g_{1N}^{n.s.}(x,Q^2)$. By imposing the requirement that
the Bjorken sum rule is satisfied we model the effect of enhancement.
  We find the effect of enhancement at $x \approx 0.125 (0.15)$ to be of an
order of $20 (55)%$ for $g_{1A=7}^{n.s. 3/2}(x,Q^2)/g_{1N}^{n.s.}(x,Q^2)$ and
$14 (40)%$ for $g_{1A=3}^{n.s}(x,Q^2)/g_{1N}^{n.s.}(x,Q^2)$, if enhancement
occupies the region $0.05 \leq x \leq 0.2$ ($0.1 \leq x \leq 0.2$). We predict
a 2% effect in the difference of the scattering cross sections of deep
inelastic scattering of an unpolarized projectile off $^7$Li with $M_{J}$=3/2
and $M_{J}$=1/2. We also show explicitly that the many-nucleon description of
deep inelastic scattering off $^7$Li becomes invalid in the enhancement region
$0.05 < x \leq 0.2$.


title: A Study of the Charged Scalar in the Zee Model

abstract:
  An extension of the Zee model involving a light right handed neutrino, nu_R
is considered. We update constraints on couplings between the bilepton scalar,
the active neutrinos, nu_R and the charged leptons. We find that the most
stringent constraint currently comes from measurements limiting the width of
the decay mu -> e gamma. These are used to predict the upper bound on violation
of lepton universality in leptonic W boson decays and rare Z decays, such as Z
-> e mu.


title: Long distance effects on the B\to X_s\gamma photon energy spectrum

abstract:
  We compute long distance effects on the photon energy spectrum in inclusive
radiative decays of $B$ mesons using light-cone expansion and heavy quark
effective theory. We show that for sufficiently high photon energy the leading
nonperturbative QCD contribution is attributed to the distribution function.
The distribution function is found to be universal in the sense that the same
distribution function also encodes the leading nonperturbative contribution to
inclusive semileptonic decays of $B$ mesons at large momentum transfer. Some
basic properties of the distribution function are deduced in QCD. Ways of
extracting the distribution function directly from experiment and their
implications are discussed. The theoretically clean methods for the
determination of $|V_{ts}|$ are described.


title: Hierarchical Neutrinos and Supersymmetric Inflation

abstract:
  A moderate extension of MSSM based on a left-right symmetric gauge group,
within which hybrid inflation is `naturally' realized, is discussed. The mu
problem is solved via a Peccei-Quinn symmetry. Light neutrinos acquire
hierarchical masses by the seesaw mechanism. They are taken from the small
angle MSW resolution of the solar neutrino puzzle and the SuperKamiokande data.
The range of parameters consistent with maximal nu_mu-nu_tau mixing and the
gravitino constraint is determined. The baryon asymmetry of the universe is
generated through a primordial leptogenesis. The subrange of parameters, where
the baryogenesis constraint is also met, is specified. The required values of
parameters are more or less `natural'.


title: Integrability and WKB solution of twist-three evolution equations

abstract:
  We identify an integrable one-dimensional inhomogeneous three-site open spin
chain which arises in the problem of diagonalization of twist-three quark-gluon
evolution equations in QCD in the chiral-odd sector. Making use of the
existence of a non-trivial `hidden' integral of motion the problem of
diagonalization of the evolution kernels is reduced to the study of a second
order finite-difference equation which is solved in WKB approximation for large
conformal spins of the three-particle system. The energies (alias anomalous
dimensions) of eigenstates with different scale dependence are found in
limiting cases and compared with numerical calculations.


title:
The renormalized gauge coupling and non-perturbative tests of
  dimensional reduction

abstract:
  In 4d lattice simulations of Standard Model like theories, the renormalized
gauge coupling in the broken phase can be determined from the prefactor of the
Yukawa term in the static potential. We compute the same quantity in terms of
the conventional MSbar scheme gauge coupling. The result allows for a further
non-perturbative test of finite temperature dimensional reduction, by a
comparison of the critical temperatures for the electroweak phase transition as
obtained with 4d lattice simulations and with 3d effective theory simulations.


title: Gluon Condensate and Quark Propagation in the QGP

abstract:
  A calculation of the thermal quark propagator is presented taking the gluon
condensate above the critical temperature into account. The quark dispersion
relation following from this propagator is derived.


title: One-Loop Splitting Amplitudes in Gauge Theory

abstract:
  We recompute the functions describing the collinear factorization of one-loop
amplitudes using the unitarity-based method. We present the results in a form
suitable for use as an ingredient in two-loop calculations. We also present a
function summarizing the behavior at one loop in both the soft and collinear
limits.


title:
The Infrared Behavior of One-Loop QCD Amplitudes at
  Next-to-Next-to-Leading Order

abstract:
  We present universal factorization formulas describing the behavior of
one-loop QCD amplitudes as external momenta become either soft or collinear.
Our results are valid to all orders in the dimensional regularization
parameter, $\eps$. Terms through $\Ord(\eps^2)$ can contribute in infrared
divergent phase space integrals associated with next-to-next-to-leading order
jet cross-sections.


title: Neutrino propagation in matter with general interactions

abstract:
  We present a general analysis of the effective potential for neutrino
propagation in matter, assuming a generic set of Lorentz invariant
non-derivative interactions. We find that in addition to the known vector and
axial vector terms, in a polarized medium also tensor interactions can play an
important role. We compute the effective potential arising from a tensor
interaction. We show that the components of the tensor potential transverse to
the direction of the neutrino propagation can induce a neutrino spin-flip,
similar to the one induced by a transverse magnetic field.


title: Measuring V_ub in Inclusive B Decays to Charm

abstract:
  We propose a novel method of measuring the CKM matrix element V_ub, via
inclusive B decays to "wrong sign" charm. This process is mediated by the quark
level decay b -> u cbar s'. When normalized to the inclusive semileptonic decay
rate, the theoretical expression is very well behaved, with small uncertainties
from unknown quark masses and no leading renormalon ambiguity. We compute the
decay rate for this process, including the leading perturbative and
nonperturbative corrections.


title:
Gaugino pair production at LHC for the case of nonuniversal gaugino
  masses

abstract:
  We investigate \chi^{+/-}_1 \chi^0_2 pair production at LHC (CMS) with
subsequent decays into leptons for the case of nonuniversal gaugino masses.
Visibility of signal by an excess over SM background in 3 leptons + no jet +
E^{miss}_T events depends rather strongly on the relation between LSP mass
\chi^0_1 and \chi^{+/-}_1 mass. We also give some preliminary results on the
investigation of squark and gluino production at LHC for the case of
nonuniversal gaugino masses.


title:
The Virtual Compton Amplitude in the Generalized Bjorken Region:
  Twist--2 Contributions

abstract:
  A systematic derivation is presented of the twist-2 anomalous dimensions of
the general quark and gluon light-ray operators in the generalized Bjorken
region in leading order both for unpolarized and polarized scattering. Various
representations of the anomalous dimensions are derived both in the non-local
and the local light cone expansion and their properties are discussed in
detail. Evolution equations for these operators are derived using different
representations. General two- and single-variable evolution equations are
presented for the expectation values of these operators for non-forward
scattering. The Compton amplitude is calculated in terms of these distribution
amplitudes. In the limit of forward scattering a new derivation of the integral
relations between the twist-2 contributions to the structure functions is
given. Special limiting cases which are derived from the general relations are
discussed, as the forward case, near-forward scattering, and vacuum-meson
transition. Solutions of the two-variable evolution equations for non-forward
scattering are presented.


title: Measurement of R Between 2-5 GeV

abstract:
  We have obtained measurements of the total cross section for e+e-
annihilation into hadronic final states for 6 energy points (2.6, 3.2, 2.4,
3.55, 4.6, and 5.0 GeV) with the upgraded Beijing Spectrometer (BESII). We
report preliminary values from this data and outline future plans for a finer
scan in the 2-5 GeV energy range.


title: Quantum corrections from nonresonant WW scattering

abstract:
  An estimate is presented of the leading radiative corrections to low energy
electroweak precision measurements from strong nonresonant WW scattering at the
TeV energy scale. The estimate is based on a novel representation of
nonresonant scattering in terms of the exchange of an effective scalar
propagator with simple poles in the complex energy plane. The resulting
corrections have the form of the corrections from the standard model Higgs
boson with the mass set to the unitarity scale for strong WW scattering.


title: Coulomb Effects in Low Energy Proton-Proton Scattering

abstract:
  Using a recently developed effective field theory for the interactions of
nucleons at non-relativistic energies, we calculate non-perturbatively Coulomb
corrections to proton-proton scattering. Including the dimension-eight
derivative interaction in the PDS regularization scheme, we recover a modified
form of the Blatt-Jackson relation between the scattering lengths. The
effective range receives no corrections from the Coulomb interactions to this
order. Also the case of scattering in channels where the Coulomb force is
attractive, is considered. This is of importance for hadronic atoms.


title: On the Realization of Assisted Inflation

abstract:
  We consider conditions necessary for a successful implementation of so-called
assisted inflation. We generalize the applicability of assisted inflation
beyond exponential potentials as originally proposed to include standard
chaotic (\lambda \phi^4 or m^2 \phi^2) models as well. We also demonstrate that
in a purely 4-dimensional theory, unless the assisted sector is in fact
decoupled, the additional fields of the assisted sector actually impede
inflation. As a specific example of an assisted sector, we consider a
5-dimensional KK model for which the extra dimension may be somewhat or much
larger than the inverse Planck scale. In this case, the assisted sector (coming
from a KK compactification) eliminates the need for a fine-tuned quartic
coupling to drive chaotic inflation. This is a general result of models with
one or more "large" extra dimensions.


title:
The Infrared Behavior of QCD Cross Sections at Next-to-Next-to-Leading
  Order

abstract:
  In this talk we examine how one-loop soft and collinear splitting functions
occur in the calculation of next-to-next-to-leading order (NNLO) corrections to
production rates, and we present the one-loop gluon soft and splitting
functions, computed to all orders in the dimensional regularization parameter
$\epsilon$. We apply the one-loop gluon soft function to the calculation of the
next-to-leading logarithmic corrections to the Lipatov vertex to all orders in
$\epsilon$.


title:
Size of Fundamental Particles and Selfgravitating Particlelike
  Structures with de Sitter Core

abstract:
  The process e(+) e(-) -> n gamma (n>=2) are studied to estimate the total and
differential cross sections of these reactions using the L3 data collected
during 1991-1998 at centre of mass energies in the range 91-193 GeV. The lower
limits obtained at 95% confidence level are, on a contact interaction enerygy
scale Lambda > 1065 GeV, and on the mass of an excited electron m*_e > 263 GeV.
The upper and lower limits on the gravitational size of fundamental particles
are estimated using the model of selfgravitating particlelike structure with de
Sitter core, which gives an estimate for self-coupling of the Higgs field
lambda <= pi/16 and for the mass of the Higgs scalar m_H <= 154 GeV.


title: Non-equilibrium initial conditions from pQCD for RHIC and LHC

abstract:
  We calculate the initial non-equilibrium conditions from perturbative QCD
(pQCD) within Glauber multiple scattering theory for $\sqrt s =200$ AGeV and
$\sqrt s =5.5$ ATeV. At the soon available collider energies one will
particularly test the small $x$ region of the parton distributions entering the
cross sections. Therefore shadowing effects, previously more or less
unimportant, will lead to new effects on variables such as particle
multiplicities $dN/dy$, transverse energy production $d\bar{E}_T/dy$, and the
initial temperature $T_i$. In this paper we will have a closer look on the
effects of shadowing by employing different parametrizations for the shadowing
effect for valence quarks, sea quarks and gluons. Since the cross sections at
midrapidity are dominated by processes involving gluons the amount of their
depletion is particularly important. We will therefore have a closer look on
the results for $dN/dy$, $d\bar{E}_T/dy$, and $T_i$ by using two different
gluon shadowing ratios, differing strongly in size. As a matter of fact, the
calculated quantities differ significantly.


title:
Phenomenological constraints on SUSY SU(5) GUTs with non-universal
  gaugino masses

abstract:
  We study phenomenological aspects of supersymmetric SU(5) grand unified
theories with non-universal gaugino masses. For large tan beta, we investigate
constraints from the requirement of successful electroweak symmetry breaking,
the positivity of stau mass squared and the b to s gamma decay rate. In the
allowed region, the nature of the lightest supersymmetric particle is
determined. Examples of mass spectra are given. We also calculate loop
corrections to the bottom mass due to superpartners.


title: Light-cone wave functions of the photon: classification up to twist four

abstract:
  The different light-cone wave functions of the photon up to twist four are
defined. Some explicit expressions are extracted from results of Balitskii and
al., Ali and Braun.


title:
Target Fragmentation in Semi-Inclusive DIS: Fracture Functions, Cut
  Vertices and the OPE

abstract:
  We discuss semi-inclusive Deep Inelastic Scattering (DIS) in the z -> 1
limit, in particular the relationship between fracture functions, generalised
cut vertices and Green functions of the composite operators arising in the OPE.
The implications, in the spin-polarised case, for testing whether the "proton
spin" effect is target-independent are explored. Explicit calculations in
(phi^3)_6 theory are presented which are consistent with our observations.


title: Conformal string operators and evolution of skewed parton distributions

abstract:
  We have investigated skewed parton distributions in coordinate space. We
found that their evolution can be described in a simple manner in terms of
non-local, conformal operators introduced by Balitsky and Braun. The resulting
formula is given by a Neumann series expansion. Its structure resembles, for
all values of the asymmetry parameter, the well-known solution of the ERBL
equation in the momentum space. Performing Fourier transformation we have
reproduced known results for evolution of momentum-space distributions.


title:
The static $Q\bar Q$ interaction at small distances and OPE violating
  terms

abstract:
  Nonperturbative contribution to the one-gluon exchange produces a universal
linear term in the static potential at small distances $\Delta V=\frac{6N_c
\alpha_s \sigma r}{2\pi}$. Its role in the resolution of long--standing
discrepancies in the fine splitting of heavy quarkonia and improved agreement
with lattice data for static potentials is discussed, as well as implications
for OPE violating terms in other processes.


title: NN interaction in a Goldstone boson exchange model

abstract:
  Adiabatic nucleon-nucleon potentials are calculated in a six-quark
nonrelativistic chiral constituent quark model where the Hamiltonian contains a
linear confinement and a pseudoscalar meson (Goldstone boson) exchange
interaction between quarks. Calculations are performed both in a cluster model
and a molecular orbital basis, through coupled channels. In both cases the
potentials present an important hard core at short distances, explained through
the dominance of the [51]_{FS} configuration, but do not exhibit an attractive
pocket. We add a scalar meson exchange interaction and show how it can account
for some middle-range attraction.


title:
Non-equilibrium phase transitions in condensed matter and cosmology:
  spinodal decomposition, condensates and defects

abstract:
  These lectures address the dynamics of phase ordering out of equilibrium in
condensed matter and in quantum field theory in cosmological settings,
emphasizing their similarities and differences. In condensed matter we describe
the phenomenological approach based on the Time Dependent Ginzburg-Landau
(TDGL) description. After a general discussion of the main experimental and
theoretical features of phase ordering kinetics and the description of linear
(spinodal) instabilities we introduce the scaling hypothesis and show how a
dynamical correlation length emerges in the large N limit in condensed matter
systems. The large N approximation is a powerful tool in quantum field theory
that allows the study of non-perturbative phenomena in a consistent manner. We
study the exact solution to the dynamics after a quench in this limit in
Minkowski space time and in radiation dominated Friedman-Robertson-Walker
Cosmology. There are some remarkable similarities between these very different
settings such as the emergence of a scaling regime and of a dynamical
correlation length at late times that describe the formation and growth of
ordered regions. In quantum field theory and cosmology this length scale is
constrained by causality and its growth in time is also associated with
coarsening and the onset of a condensate. We provide a density matrix
interpretation of the formation of defects and the classicalization of quantum
fluctuations.


title:
Profiles of the Unitarity Triangle and CP-Violating Phases in the
  Standard Model and Supersymmetric Theories

abstract:
  We report on a comparative study of the profile of the CKM unitarity
triangle, and the resulting CP asymmetries in B decays, in the standard model
and in several variants of the minimal supersymmetric standard model (MSSM),
characterized by a single phase in the quark flavour mixing matrix. The
supersymmetric contributions to the mass differences \Delta M_d, \Delta M_s and
to the CP-violating quantity |\epsilon| are, to an excellent approximation,
equal to each other in these theories, allowing for a particularly simple way
of implementing the resulting constraints on the elements of V_{CKM} from the
present knowledge of these quantities. Incorporating the next-to-leading-order
corrections and applying the current direct and indirect constraints on the
supersymmetric parameters, we find that the predicted ranges of \sin 2 \beta in
the standard model and in MSSM models are very similar. However, precise
measurements at B-factories and hadron machines may be able to distinguish
these theories in terms of the other two CP-violating phases \alpha and \gamma.
This is illustrated for some representative values of the supersymmetric
contributions in \Delta M_d, \Delta M_s and |\epsilon|.


title: Three Lectures on the Physics of Small x and High Gluon Density

abstract:
  In these lectures, I shall discuss small x physics and the consequences of
high gluon density which arises as x decreases. I argue that an understanding
of this problem would lead to knowledge of the high energy asymptotics of
hadronic processes. The high gluon density should allow a first principles
computation of these asymptotics from QCD.


title: Some decay modes of the $1^{-+}$ hybrid meson in QCD sum rules revisited

abstract:
  The pionic coupling constants in the decays of the $1^{-+}$ hybrid meson are
calculated. The double Borel transformation is invoked and continuum
contribution is subtracted. The decay widths of the processes $1^{-+}\to
\rho\pi, f_1 \pi, \pi \gamma$ are around $40, 100, 0.3$ MeV respectively.


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

abstract:
  We consider the production of gravitons via two photon fusion in Kaluza-Klein
theories which allow TeV scale gravitational interactions. We find that the
processes l+ l- to l+ l- + graviton, with l=electron or muon can put quite
stringent bounds on such theories. For example, with two extra dimensions at
the Next Linear Collider with a center of mass energy of 500 (1000) GeV
attainable bounds on the scale of the gravitational interactions can reach
about 6 (9) TeV.


title: Superconducting Semilocal Stringy (Hopf) Textures

abstract:
  The dynamics of texture-like configurations are briefly reviewed. Emphasis is
given to configurations in 2+1 dimensions which are constructed numerically.
Confirming previous semi-analytical studies it is shown that they can be
stabilized by partial gauging of the vacuum manifold (semilocality) in a finite
range of parameter space. When these configurations are extended to 3+1
dimensions (stringy textures) it is shown that they can support persistent
currents if a twist (Hopf charge) is introduced in the scalar field sector. The
pressure induced by these persistent currents is also studied in closed loops.
In the context of a simple model, twist induced pressure is shown to be
insufficient to stabilize the loops against collapse due to tension


title:
Extracting CKM Phases from Angular Distributions of $B_{d,s}$ Decays
  into Admixtures of CP Eigenstates

abstract:
  The time-dependent angular distributions of certain $B_{d,s}$ decays into
final states that are admixtures of CP-even and CP-odd configurations provide
valuable information about CKM phases and hadronic parameters. We present the
general formalism to accomplish this task, taking also into account penguin
contributions, and illustrate it by considering a few specific decay modes. We
give particular emphasis to the decay $B_d\to J/\psi \rho^0$, which can be
combined with $B_s\to J/\psi \phi$ to extract the $B^0_d - \bar{B^0_d}$ mixing
phase and - if penguin effects in the former mode should be sizeable - also the
angle $\gamma$ of the unitarity triangle. As an interesting by-product, this
strategy allows us to take into account also the penguin effects in the
extraction of the $B^0_s - \bar{B^0_s}$ mixing phase from $B_s\to J/\psi \phi$.
Moreover, a discrete ambiguity in the extraction of the CKM angle $\beta$ can
be resolved, and valuable insights into SU(3)-breaking effects can be obtained.
Other interesting applications of the general formalism presented in this
paper, involving $B_d\to\rho \rho$ and $B_{s,d}\to K^{\ast} \bar{K^\ast}$
decays, are also briefly noted.


title:
A Phenomenological Study of Heavy-Quark Fragmentation Functions in e+e-
  Annihilation

abstract:
  We consider the computation of D and B fragmentation functions in e+e-
annihilation. We compare the results of fitting present data using the
next-to-leading-logarithmic resummed approach, versus the O(alpha_s^2)
fixed-order calculation, including also mass-suppressed effects. We also
propose a method for merging the fixed-order calculation with the resummed
approach.


title: Ultra High Energy Cosmic Rays and Inflation Relics

abstract:
  There are two processes of matter creation after inflation that may be
relevant to the resolution of the puzzle of cosmic rays observed with energies
beyond GZK cut-off: 1) gravitational creation of superheavy (quasi)stable
particles, and 2) non-thermal phase transitions leading to formation of
topological defects. We review both possibilities.


title: On Large Final-State Phases in Heavy Meson Decays

abstract:
  An attempt is made to identify circumstances under which the weak decays of
$D$ and $B$ mesons may display large differences between eigenphases of strong
final-state interactions. There are several cases in which rescattering from
other final states appears to enhance decay rates with respect to estimates
based on the factorization hypothesis.


title: CP violation in supersymmetric model with non-degenerate A-terms

abstract:
  We study the CP phases of the soft supersymmetry breaking terms in
string-inspired models with non-universal trilinear couplings. We show that
such non-universality plays an important role on all CP violating processes. In
particular these new supersymmetric sources of CP violation may significantly
contribute to the observed CP phenomena in kaon physics while respecting the
severe bound on the electric dipole moment of the neutron.


title: High Energy Fluxes from a Non-Scaling Cosmic String Network

abstract:
  Topological defects, particularly cosmic strings, can provide a mechanism to
produce particles with energies of the order 10^21 eV and higher. Here, we
report on order of magnitude calculations of fluxes from a cosmic string
network which evolves according to a new scenario according to which the main
channel for energy loss is the particle production rather than gravitational
radiation. We compare the predicted fluxes for protons (anti-protons) and
neutrinos (anti-neutrinos) with observations of extremely high energy cosmic
rays.


title:
An effective field theory approach to the electroweak corrections at LEP
  energies

abstract:
  In the framework of the effective field theory (EFT) we discuss the
electroweak (EW) corrections at LEP energies. We obtain the effective
Lagrangian in the large m_t limit, and reproduce analytically the dominant EW
corrections to the LEP2 processes e+ e- --> gamma Z and e+ e- --> Z Z. To
include effects of finite top-quark and Higgs masses, we use the effective
Lagrangian at tree level and fit LEP1/SLD observables with four arbitrary
parameters, plus alpha_s(m_Z). The EFT approach works remarkably well. Using
the effective couplings determined from the fit, and tree-level EFT formulae,
we predict the cross sections for e+ e- --> Z Z, gamma Z at a level better than
1%.


title: How to Find the QCD Critical Point

abstract:
  The event-by-event fluctuations in heavy ion collisions carry information
about the thermodynamic properties of the hadronic system at the time of
freeze-out. By studying these fluctuations as a function of varying control
parameters, such as the collision energy, it is possible to learn much about
the phase diagram of QCD. As a timely example, we stress the methods by which
present experiments at the CERN SPS can locate the second order critical point
at which a line of first order phase transitions ends. Those event-by-event
signatures which are characteristic of freeze-out in the vicinity of the
critical point will exhibit nonmonotonic dependence on control parameters. We
focus on observables constructed from the multiplicity and transverse momenta
of charged pions. We find good agreement between NA49 data and thermodynamic
predictions for the noncritical fluctuations of such observables. We then
analyze the effects due to the critical fluctuations of the sigma field. We
estimate the size of these nonmonotonic effects which appear near the critical
point, including restrictions imposed by finite size and finite time.


title:
Sensitivity to Gauge-Mediated Supersymmetry Breaking Models of the
  Fermilab Upgraded Tevatron Collider

abstract:
  This paper discusses supersymmetry discovery potential of the upgraded D\O
experiment at the Tevatron $p\bar{p}$ collider. Six final states with large
transverse energy (momentum) leptons or photons (with or without large
transverse momentum imbalances) are studied. These final states are expected to
have small backgrounds and are thereby ideal for new physics searches.
Implications of the analyses of these final states on Gauge Mediated
Supersymmetry Breaking models are discussed for integrated luminosities of 2
and 30 1/fb. This study demonstrates that a large class of supersymmetry models
can be probed at the upgraded Tevatron.


title:
Single-top-squark production via R-parity-violating supersymmetric
  couplings in hadron collisions

abstract:
  Single-top-squark production via q q' -> \bar{\tilde{t_1}} probes
R-parity-violating extensions of the minimal supersymmetric standard model
though the \lambda''_{3ij} couplings. For masses in the range 180-325 GeV, and
\lambda''_{3ij} > 0.02-0.06, we show that discovery of the top squark is
possible with 2 fb^{-1} of integrated luminosity at run II of the Fermilab
Tevatron. The bound on \lambda''_{3ij}$ can be reduced by up to an order of
magnitude with existing data from run I, and by two orders of magnitude at run
II if the top squark is not found.


title: Preheating, Parametric Resonance and the Einstein Field Equations

abstract:
  We consider the interaction between perturbations in the inflaton and in the
metric during the preheating phase in simple inflationary models. By
numerically integrating the Einstein field equations we are able to gauge the
impact of non-linear gravitational effects on preheating for the first time. In
the lambda phi^4 model we find a large increase in the amplitude of sub-Hubble
metric modes, beyond that due to gravitational collapse alone. There is
significant mode-mode coupling and the amplification is eventually terminated
by back reaction effects. We suggest that such enhancement of inhomogeneity
will change the behaviour of the post-inflationary universe.


title: $\Lambda_s (1405)$ and Negative Parity Baryon States

abstract:
  After a brief historical background on the $\Ls$, we revisit the 25 year old
controversy on whether $\Ls$ is a $qqq$ (L=1) three quark state or a $\K$ quasi
virtual bound state. This work is stimulated by the recent suggestion of Isgur
that s be treated as a heavy quark in heavy quark effective theory HQET. We
re-examine the empirical evidence for minimal mixing amongst singlets and
octets in negative parity baryon states, with a possible dynamical origin in
the opening of inelastic threshold channels. Finally, we suggest that $\Ls$
belongs to a class of hadrons which are described simultaneously as $qqq$ or $q
\bar{q}$ states and as hadronic bound states.


title:
Can the Super-Kamiokande Atmospheric Data Predict the Solar Neutrino
  Deficit ?

abstract:
  In this Letter we show that the evidence for neutrino oscillations from the
Super-Kamiokande atmospheric neutrino data fully determines the 3x3
neutrino-oscillations mixing matrix and predicts an energy independent solar
neutrino deficit at the level of 45%. This corresponds to a ratio of measured
to predicted neutrino flux of R_e^{Solar} = 0.55, in good agreement with the
experimental results. We achieve this result within the framework of a minimal,
three-generations neutrino mixing, with mass squared differences of dM^2 = 0.45
eV^2 and dm^2 = O(10^-3) eV^2. The mixing matrix derived here is characterized
by the mixing angles theta = 35.1, beta = 5.5, and psi = 23.3, and a vanishing
CP-violating phase, delta = 0.


title:
The Theta Term in QCD Sum Rules and the Electric Dipole Moment of the
  Vector Meson

abstract:
  We demonstrate that the QCD sum rule method can be successfully applied to
the calculation of CP-odd electromagnetic observables induced by a vacuum
theta--angle. We implement the approach in calculating the electric dipole
moment of the rho meson to ~30% precision, and find that the result can also be
explicitly related to the vacuum topological susceptibility.


title: The angular distribution of the reaction $\bar{\nu}_e + p \to e^+ + n$

abstract:
  The reaction $\bar{\nu}_e + p \to e^+ + n$ is very important for low-energy
($E_\nu \lesssim 60$ MeV) antineutrino experiments. In this paper we calculate
the positron angular distribution, which at low energies is slightly backward.
We show that weak magnetism and recoil corrections have a large effect on the
angular distribution, making it isotropic at about 15 MeV and slightly forward
at higher energies. We also show that the behavior of the cross section and the
angular distribution can be well-understood analytically for $E_\nu \lesssim
60$ MeV by calculating to ${\cal O}(1/M)$, where $M$ is the nucleon mass. The
correct angular distribution is useful for separating $\bar{\nu}_e + p \to e^+
+ n$ events from other reactions and detector backgrounds, as well as for
possible localization of the source (e.g., a supernova) direction. We comment
on how similar corrections appear for the lepton angular distributions in the
deuteron breakup reactions $\bar{\nu}_e + d \to e^+ + n + n$ and $\nu_e + d \to
e^- + p + p$. Finally, in the reaction $\bar{\nu}_e + p \to e^+ + n$, the
angular distribution of the outgoing neutrons is strongly forward-peaked,
leading to a measurable separation in positron and neutron detection points,
also potentially useful for rejecting backgrounds or locating the source
direction.


title: Electroweak symmetry breaking and s-spectrum in M-theory

abstract:
  We study soft SUSY breaking parameters in M-theory with and without 5-brane
moduli fields. We investigate successful electroweak symmetry breaking and the
positivity of stau mass squared. We study mass spectra in allowed regions.


title: Fixed-Angle Elastic Hadron Scattering

abstract:
  The scattering amplitude in the dual model with Mandelstam analyticity and
trajectory $\alpha (s)=\alpha_{0}-\gamma \ln [ (1+\beta \sqrt{s_{0} -s})/(1+
\beta \sqrt{s_{0}})]$ is studied in the limit $s,|t|\to \infty, s/t=const.$ By
using the saddle point method, a series decomposition for the scattering
amplitude is obtained, with the leading and two sub-leading terms calculated
explicitly.


title:
The top quark mass in the minimal top condensation model with extra
  dimensions

abstract:
  The minimal dynamical electroweak symmetry breaking through top condensation
in the presence of compact large extra dimensions is studed. It is shown that
thanks to the power-low evolution of gauge and Yukawa couplings the original
BHL predictions for the top quark mass are significantly lowered and even for
small cut-off scale $\Lambda \sim few$ TeV one can obtain experimentally
allowed values.


title:
Implementation of the recovering corrections into the intermittent data
  analysis

abstract:
  The improved method of intermittent data analysis is proposed. It exploits,
in addition to the standard density moments, the information on the bin-bin
correlations, observed in the data and expressed in terms of the density
correlators. The improving recovering corrections are implemented into the data
analysis in the form of the recursive algorithm, and tested in the framework of
multiplicative cascading models.


title:
Off-diagonal helicity density matrix elements for vector mesons produced
  in polarized e+e- processes

abstract:
  Final state quark-antiquark interactions give origin to non zero values of
the off-diagonal element rho_{1,-1} of the helicity density matrix of vector
mesons produced in e+e- annihilations, as confirmed by recent OPAL data on Phi,
D^* and K^*'s. New predictions are given for rho_{1,-1} of several mesons
produced at large x_E and small p_T -- i.e. collinear with the parent jet -- in
the annihilation of polarized e+ and e-; the results depend strongly on the
elementary dynamics and allow further non trivial tests of the Standard Model.


title: Production of spin 3/2 particles from vacuum fluctuations

abstract:
  We study the production of spin 3/2 particles in homogeneous scalar and
gravitational backgrounds from the mode-mixing Bogolyubov method. Considering
only helicity $\pm 3/2$ states we can reduce the problem to a standard Dirac
fermion calculation and apply the standard techniques in a straightforward way.
As an example we consider a supergravity inflationary model and calculate the
spectrum of gravitinos created during preheating at the end of inflation.


title: Precision Tests of Electroweak Physics

abstract:
  We review the current status of precision electroweak measurements and the
constraints they impose on new physics. We perform a model independent analysis
using the STU-formalism of Ref. 1, and then discuss how the Z-pole data from
LEP and SLD can be used to constrain models that are not covered within that
framework.


title:
Leading/nonleading charm production asymmetry in $\Sigma^-p$
  interactions

abstract:
  The asymmetries between the spectra of leading and nonleading charmed mesons
measured in $\Sigma^-A$ interactions at $p_L$= 340 GeV/c in the WA89 experiment
are described in the framework of Quark-Gluon String Model. There are two
versions of the model under consideration: one of them includes the sea charm
quark-antiquark pairs and the other one does not. It's shown that the
asymmetries between $D^-$ and $D^+$-meson spectra and between $D_s^-$ and
$D^+_s$- meson spectra can be fitted by QGSM curves obtained with the same
parameters as charm asymmetry in $\pi^-A$ experiments described in previous
studies. The QGSM results are compared with the calculations in the
next-to-leading approximation of perturbative QCD approach carried out by the
other authors.


title:
Constraining the Sneutrino Mass in Chargino Production and Decay with
  Polarized Beams

abstract:
  Production and decay of gaugino-like charginos are crucially determined by
sneutrino exchange. Therefore we study the pair production of charginos e^+ e^-
-> chi^+_1 chi^-_1 with polarized beams and the subsequent decay chi^-_1 ->
chi^0_1 e^- nu_e, including the complete spin correlations between production
and decay. The spin correlations have strong influence on the decay angular
distribution and on the corresponding forward-backward asymmetry. We show for
two representative scenarios for sqrt{s}=270 GeV and for sqrt{s}=500 GeV that
forward-backward asymmetries for polarized beams are an important tool for
constraining the sneutrino mass m_{tilde{nu}_e}.


title:
Atmospheric and Solar Neutrinos from Single Right-Handed Neutrino
  Dominance and U(1) Family Symmetry

abstract:
  We argue that in order to provide a natural explanation of both neutrino mass
hierarchies and large neutrino mixing angles, as required by the atmospheric
neutrino data, a single right-handed neutrino must give the dominant
contribution to the 23 block of the light effective neutrino matrix, and
illustrate this mechanism in the framework of models with U(1) family
symmetries. Sub-dominant contributions from other right-handed neutrinos are
required to give small mass splittings appropriate to the small angle MSW
solution to the solar neutrino problem. We give general conditions for
achieving this in the framework of U(1) family symmetry models containing
arbitrary numbers of right-handed neutrinos, and show how the resulting
neutrino mass hierarchies and mixing angles may be expanded in terms of the
Wolfenstein parameter.


title: Probing Large Extra Dimensions with Neutrinos

abstract:
  We study implications of theories with sub-millimeter extra dimensions and
$M_f \sim (1 - 10) $ TeV scale quantum gravity for neutrino physics. In these
theories, the left-handed neutrinos as well as other standard model (SM)
particles, are localized on a brane embedded in the bulk of large extra space.
Mixing of neutrinos with (SM) singlet fermions propagating in the bulk is
naturally suppressed by the volume factor $M_f/M_P \sim 3\cdot 10^{-16} -
3\cdot 10^{-15}$, where $M_P$ is the Planck mass. Properties of the neutrino
oscillations and the resonance conversion to the bulk fermions are considered.
We show that the resonance conversion of the electron neutrinos to the light
bulk fermions can solve the solar neutrino problem. The signature of the
solution is the peculiar distortion of the solar neutrino spectrum. The
solution implies that the radius of at least one extra dimension should be in
the range 0.06 - 0.1 mm {\it irrespective} of total number of extra dimensions.
The corresponding modification of the Newtonian law is within the range of
sensitivity of proposed sub-millimeter experiments, thus providing a verifiable
link between neutrino physics and the gravity measurements.