title: Time ordering in off-diagonal parton distributions

abstract:
  We investigate the relevance of time ordering in the definition of
off-diagonal parton distributions in terms of products of fields. The method we
use easily allows determination of their support properties and provides a link
to their interpretation from a parton point of view. It can also readily be
applied to meson distribution amplitudes.}


title: Precision Supersymmetry Measurements at the e^-e^- Collider

abstract:
  Measurements of supersymmetric particle couplings provide important
verification of supersymmetry. If some of the superpartners are at the
multi-TeV scale, they will escape direct detection at planned future colliders.
However, such particles induce nondecoupling corrections in processes involving
the accessible superparticles through violations of the supersymmetric
equivalence between gauge boson and gaugino couplings. These violations are
analogous to the oblique corrections in the electroweak sector of the standard
model, and can be parametrized in terms of super-oblique parameters. The $e^-
e^-$ collision mode of a future linear collider is shown to be an excellent
environment for such high precision measurements of these SUSY parameters,
which will provide an important probe of superparticles beyond reachable
energies.


title: Supersymmetric Grand Unification

abstract:
  These lectures begin with a brief introduction to the minimal supersymmetric
standard model (MSSM) and the various mechanisms for hidden sector
supersymmetry breaking and go on to provide a pedagogical discussion of the
various kinds of supersymmetric unified theories beyond the MSSM including SUSY
GUTs. Their implications for proton decay, R-parity violation, doublet triplet
splitting etc. are discussed. Exhaustive discussion of SU(5) and SO(10) models
is given. Other GUT models such as those based on $E_6$, $SU(5)\times SU(5)$,
flipped SU(5) and SU(6) are also presented.


title: T-Odd Gluon-Top-Quark Couplings at LHC

abstract:
  The T-odd top-quark chromoelectric dipole moment, $d_t$, is probed through
top-quark-pair production via gluon fusion at the CERN LHC with the possibility
of having polarized proton beams in account. At 1-$\sigma$ level, the typical
CP-odd lepton energy and tensor correlations enable us to measure $Re(d_t)$ and
$Im(d_t)$ up to the order of 10$^{-18}$ ($g_scm$) in the unpolarized case and
the initial CP-odd gluon spin correlation allows us to probe $Im(d_t)$ up to
the order of 10$^{-20}$ ($g_scm$) for $\sqrt{s}=14$ TeV and the integrated
luminosity $L_{pp}=10 fb^{-1}$.


title:
Using B_d^0, B_s^0 Decays at Hadronic B-Factories to Determine CP Angles
  alpha and beta

abstract:
  At the first PPPP workshop, I gave a review talk on physics of B and
CP-phases. In my talk, I explained DRG method and our extension to extract CP
angles $\alpha$ and $\gamma$ from measurements of the decay rates of $B_{d,s}^0
\to \pi\pi, \pi K, K K$. There are several advantages to this extension:
discrete ambiguities are removed, fewer assumptions are necessary, and the
method works even if all strong phases vanish. I also talked on several other
topics.


title: Bounds on Supersymmetry from Electroweak Precision Analysis

abstract:
  The Standard Model global fit to precision data is excellent. The Minimal
Supersymmetric Standard Model can also fit the data well, though not as well as
the Standard Model. At best, supersymmetric contributions either decouple or
only slightly decrease the total chi^2, at the expense of decreasing the number
of degrees of freedom. In general, regions of parameter space with large
supersymmetric corrections from light superpartners are associated with poor
fits to the data. We contrast results of a simple (oblique) approximation with
full one-loop results, and show that for the most important observables the
non-oblique corrections can be larger than the oblique corrections, and must be
taken into account. We elucidate the regions of parameter space in both
gravity- and gauge-mediated models which are excluded. Significant regions of
parameter space are excluded, especially with positive supersymmetric mass
parameter mu. We give a complete listing of the bounds on all the superpartner
and Higgs boson masses. For either sign of mu, and for all supersymmetric
models considered, we set a lower limit on the mass of the lightest CP-even
Higgs scalar, mh > 78 GeV. Also, the first and second generation squark masses
are constrained to be above 280 (325) GeV in the supergravity (gauge-mediated)
model.


title: $D_s^+ \to \phi \rho^+$ Decay

abstract:
  Motivated by the experimental measurement of the decay rate, $\Gamma$, and
the longitudinal polarization, $P_L$, in the Cabibbo favored decay $D_s^+\to
\phi {\rho}^{+}$, we have studied theoretical prediction within the context of
factorization approximation invoking several form factors models. We were able
to obtain agreement with experiment for both $\Gamma$ and $P_L$ by using
experimentally measured values of the form factors $A_1^{D_s\phi}(0)$,
$A_2^{D_s\phi}(0)$ and $V^{D_s\phi}(0)$ in the semi-leptonic decay $D_s^+\to
\phi l^{+}\nu_{l}$. We have also included in our calculation the effect of the
final state interaction ($fsi$) by working with the partial waves amplitudes
$S$, $P$ and $D$. Numerical calculation shows that the decay amplitude is
dominated by $S$ wave, and that the polarization is sensitive to the
interference between $S$ and $D$ waves. The range of the phase difference
$\delta_{SD} = \delta_S - \delta_D$ accommodated by experimental error in $P_L$
is large.


title:
Quarkonium Polarization in Non-relativistic QCD and the Quark-Gluon
  Plasma

abstract:
  We examine angular distributions of leptons arising from the decay of J/psi
in inclusive hadroproduction. Taking into account feed-down contributions from
chi_{1,2}, a flat distribution emerges without fine tuning parameters. Changes
in the ratio of direct to total J/psi cross sections would change this
distribution significantly. Such angular distributions are, therefore,
confirmatory tests of the J/psi suppression signal for the production of a
quark-gluon plasma. Related effects are predicted for the Upsilon.


title:
Double Counting of `Chiral Anomaly' in a Model Study of Primordial
  Baryogenesis

abstract:
  In this comment to the Nature paper of Bevan et al I point out that their
interpretation of experimental data is based on a double counting of the
`chiral anomaly' due to a vortex motion: using the calculation far away from
the vortex core (Berry phase) to cancel the equivalent calculation at the core
(spectral flow). The relaxation time approximation in force or momentum balance
equation involved in their theory is also wrong, which has been rigorous proved
in transport theory since 60's. Hence their affirmative conclusion is
premature.


title:
Signatures of Non-Universal Soft Breaking Sfermion Masses at Hadron
  Colliders

abstract:
  We identify several mass patterns, within the framework of N=1 SUGRA with
nonuniversal soft breaking masses for the sfermions, which may significantly
alter SUSY signals and the current squark-gluino mass limits from the Tevatron.
These effects are illustrated in a SO(10) SUSY GUT with an intermediate mass
scale, but the conclusions are also valid in SUSY SO(10) models with grand
deserts.


title: A Strong Electroweak Sector at Future mu^+ mu^- Colliders

abstract:
  We discuss the prospects for detecting at a muon collider the massive new
vector resonances V and light pseudo-Nambu-Goldstone bosons P of a typical
strongly interacting electroweak sector (as represented by the BESS model).
Expected sensitivities to V's at a high energy collider are evaluated and the
excellent prospects for discovering P's via scanning at a low energy collider
are delineated.


title: The Fading of Symmetry Non-restoration at Finite Temperature

abstract:
  The fate of symmetries at high temperature determines the dynamics of the
very early universe. It is conceivable that temperature effects favor symmetry
breaking instead of restoration. Concerning global symmetries, the non-linear
sigma model is analyzed in detail. For spontaneously broken gauge symmetries,
we propose the gauge boson magnetic mass as a ``flag'' for symmetry
(non)-restoration. We consider several cases: the standard model with one and
two Higgs doublets in the perturbative regime, and the case of a strongly
interacting Higgs sector. The latter is done in a model independent way with
the tools provided by chiral Lagrangians. Our results clearly point towards
restoration, a pattern consistent with recent lattice computations for global
symmetries. In addition, we explicitly verify $BRST$ invariance for gauge
theories at finite temperature.


title: Dynamical Mass Generation in a Finite-Temperature Abelian Gauge Theory

abstract:
  We write down the gap equation for the fermion self-energy in a
finite-temperature abelian gauge theory in three dimensions. The instantaneous
approximation is relaxed, momentum-dependent fermion and photon self-energies
are considered, and the corresponding Schwinger-Dyson equation is solved
numerically. The relation between the zero-momentum and zero-temperature
fermion self-energy and the critical temperature T_c, above which there is no
dynamical mass generation, is then studied. We also investigate the effect
which the number of fermion flavours N_f has on the results, and we give the
phase diagram of the theory with respect to T and N_f.


title:
Limits on SUSY particle Spectra from Proton Stability and Dark Matter
  Constraints

abstract:
  It is shown that the combined constraints on the amount of cold dark matter
and of proton stability produce a stringent upper limit on the gluino mass
$m_{\tilde g}$ (and hence on the lightest neutralino mass $m_{\chi_1^0}\simeq
m_{\tilde g}/7$) for a large class of gravity mediated supergravity unified
models. One finds that for the minimal SU(5) model current data (Kamiokande)
restricts $m_{\tilde g}\leq 400$ GeV for a scalar soft breaking mass $m_0\leq
1$ TeV. Expected future data from Super Kamionkande and ICARUS will be
sensitive to the entire range of gluino mass for $m_0\leq 1$ TeV, and be able
to exclude the region $m_{\tilde g}\geq 500$ GeV for $m_0\leq 5$ TeV. Effects
of quark mass textures are studied and one finds that the bound $m_{\tilde
g}\leq 500$ GeV holds when the experimental proton lifetime for the $p\to \bar
\nu K^+$ mode becomes $\geq 5\times 10^{32}$ yr.Implications of these results
for a test of these models at the Tevatron and at the LHC are discussed. The
effects of non-universal soft breaking in the Higgs and the third generation
squark sectors are also examined, and it is found that the proton lifetime is
sensitive to these non-universal effects. The current data already eliminates
some regions of non-universalities. The constraints of proton stability on the
direct detection of dark matter are seen to reduce the maximum event rates by
as much as a factor of $10^3$.


title: Heavy Quark Productions with Spin

abstract:
  Heavy quark productions in high energy polarized scatterings are reviewed
from a personal point of view. After mentioning why heavy quark physics is so
interesting, I concentrate on two rather specific subjects: (1) polarized
$\Lambda_{c}^{+}$ productions in deep inelastic $\ell p$ scatterings and (2)
$\psi^{\prime}$ productions in polarized $pp$ collisions. The first one is an
interesting process for extracting the polarized gluon in the proton and the
second one may give another test of the color-octet model of heavy quarkonium
productions in high energy collisions.


title: R-Parity Violation and Sneutrino Resonances at Muon Colliders

abstract:
  In supersymmetric models with R-parity violation, sneutrinos may be produced
as s-channel resonances at muon colliders. We demonstrate that, for R-parity
violating couplings as low as 10^-4, sneutrino resonances may be observed and
may be exploited to yield high precision SUSY parameter measurements. The
excellent beam energy resolution of muon colliders may also be used to resolve
MeV level splittings between CP-even and CP-odd sneutrino mass eigenstates.


title: Cosmological implications of a light dilaton

abstract:
  Supersymmetric Peccei-Quinn symmetry and string theory predict a complex
scalar field comprising a dilaton and an axion. These fields are massless at
high energies, but it is known since long that the axion is stabilized in an
instanton dominated vacuum. Instantons and axions together also provide a
mechanism to stabilize a dilaton, thus accounting for a dilaton as a possible
cold dark matter component accompanying the axion. We briefly review the
prospects of this scenario and point out further implications.


title:
Limits on Anomalous Couplings from Higgs Boson Production at the
  Tevatron

abstract:
  We estimate the attainable limits on the coefficients of dimension--6
operators from the analysis of Higgs boson phenomenology, in the framework of a
$SU_L(2) \times U_Y(1)$ gauge-invariant effective Lagrangian. Our results,
based on the data sample already collected by the collaborations at Fermilab
Tevatron, show that the coefficients of Higgs-vector boson couplings can be
determined with unprecedented accuracy. Assuming that the coefficients of all
``blind'' operators are of the same magnitude, we are also able to impose more
restrictive bounds on the anomalous vector-boson triple couplings than the
present limit from double gauge boson production at the Tevatron collider.


title:
Photon Signatures for Low Energy Supersymmetry Breaking and Broken
  R-parity

abstract:
  The possible phenomenological consequences of R-parity violating interactions
in the framework of low energy supersymmetry breaking are studied. It is
pointed out that even very weak R-parity violation would completely overshadow
one of the basic signatures of low energy supersymmetry breaking models, that
is, the decay of the next to lightest supersymmetric particle into a photon
(lepton) and missing energy. Thus, the observation of these decays would put
very strong limits on R-parity violating couplings. Vice-versa, if R-parity
violation is established experimentally, before a detailed knowledge of the
spectrum is obtained, it will be very difficult to distinguish gravity mediated
from low energy gauge mediated supersymmetry breaking. Those conclusions are
very model independent. We also comment on the possibility of mixing between
charged and neutral leptons with charginos and neutralinos, respectively, and
its phenomenological consequences for the photon (lepton) signatures, in
scenarios where this mixing is generated by the presence of bilinear or
trilinear R-parity violating terms in the superpotential.


title: Higher orders and IR renormalon phenomenology in DVCS

abstract:
  We present results for higher order perturbative corrections to Compton
scattering in the generalized Bjorken kinematics. The approach we have used is
based on the combination of two techniques: conformal operator product
expansion on the one side, and resummation of the fermion vacuum insertions
with consequent restoration of the full QCD beta-function via the naive
nonabelianization assumption, on the other. These are terms which are lost in
the former approach. Due to the presence of the infrared renormalon poles in
the Borel transform of the resummed amplitude the latter suffers from
ambiguities which reflect the asymptotic character of perturbation series. The
residues of these IR renormalon poles give an estimate for the size of power
corrections in deeply virtual Compton scattering.


title:
Anthropic considerations in multiple domain theories and the scale of
  electroweak symmetry breaking

abstract:
  One of the puzzles of the Standard Model is why the mass parameter which
determines the scale of the Weak interactions is closer to the scale of QCD
than to the Grand Unification or Planck scales. We discuss a novel approach to
this problem which is possible in theories in which different regions of the
universe can have different values of the physical parameters. In such a
situation, we would naturally find ourselves in a region which has parameters
favorable for life. We explore the whole range of values of the mass parameter
in the Higgs potential, $\mu^2$, from $+M_P^2$ to $-M_P^2$ and find that there
is only a narrow window, overlapping with the observed value, in which life is
likely to be possible. The observed value of $\mu^2$ is fairly typical of the
values in this range. Thus multiple domain theories in which $\mu^2$ varies
among domains may give a promising approach to solving the fine tunign problem
and explaining the closeness of the QCD scale and the Weak scale.


title: Supersymmetry Signatures at the CERN LHC

abstract:
  These lectures, given at the 1997 TASI Summer School, describe the prospects
for discovering supersymmetry (SUSY) and for studying its properties at the
Large Hadron Collider (LHC) at CERN. If SUSY exists at a mass scale less than
1--2 TeV, then it should be easy to observe characteristic deviations from the
Standard Model at the LHC. It is more difficult to determine SUSY masses
because in most models there are two missing particles \tilde\chi_1^0 in every
event. However, it is possible to use various kinematic distributions to make
precision measurements of combinations of SUSY masses and other quantities
related to SUSY physics. In favorable cases such measurements at the LHC can
determine the parameters of the underlying SUSY model with good accuracy.


title: On the rigidity of back-to-back top quark pairs in e^+e^- annihilation

abstract:
  We consider the effect of gluon radiation on the energy of top/antitop quarks
and on the anticollinearity of top-antitop quark pairs produced in $e^+e^-$
annihilation. Our results are presented in terms of the $E_q$-dependence of the
$t\bar tg$ cross section and the dependence on the cosine of the opening angle
$\theta_{12}$ between top and antitop for a center of mass energy of
$\sqrt{q^2}=500 GeV$. We then go on to determine mean values for the top
quark's energy as well as its longitudinal and transverse projections, and for
the deviation of $\sin\theta_{12}$ and $\cos\theta_{12}$ from the
anticollinearity limits $\sin\theta_{12}=0$ and $\cos\theta_{12}=-1$. For a
center of mass energy of $500 GeV$ we obtain $<E_q>=248.22 GeV$, $<E_L>=247.24
GeV$ and $<E_T>=4.70 GeV$. Thus, at this energy gluon radiation causes a total
average energy loss of 0.71% of the top quark's energy. The average energy loss
in the longitudinal direction is 1.06% and the average energy gain in the
transverse direction is 1.88%. These percentage figures go up to 3.77%, 5.19%
and 6.06%, respectively, at $1000\GeV$. For the mean of the acollinearity angle
$\bar\theta_{12}=180^0-\theta_{12}$ we obtain $<\bar\theta_{12}>=1.25^0$ at
$500 GeV$, the value of which goes up to $4.62^0$ at $1000 GeV$. From an
analysis of the transverse momentum of the top we find that the mean transverse
momentum of the top stays close to the mean total momentum of the gluon in the
energy range from threshold to $1000 GeV$ showing that the gluon momentum has a
large mean transverse component in this energy range.


title: Second Stage String Fragmentation Model

abstract:
  A string model, advocated by Bowler, provides a physical and intuitive
picture of heavy quark fragmentation. When supplemented by an ad hoc factor of
(1-z), to suppress fragmentation near z=1, it supplies an excellent fit to the
data. We extend Bowler's model by accounting for the further decay of the
massive mesonic states produced by the initial string breaking. We find that
each subsequent string break and cascade decay beyond the first, introduces a
factor of (1-z). Furthermore we find that including a finite mass for the
quarks, which pop out of the vacuum and split the string, forces the first
string breaking to produce massive states requiring further decay. This
sequence terminates at the second stage of fragmentation where only relatively
"light" heavy meson systems are formed. Thus we naturally account for the
phenomenologically required factor of (1-z). We also predict that the ratio of
(primary) fragments-vector/(vector plus scalar) should be .61. Our second stage
string fragmentation model provides an appealing picture of heavy quark
fragmentation.


title:
Unitarization of Gluon Exchange Amplitudes and Rapidity Gaps at the
  Tevatron

abstract:
  Rapidity gaps between two hard jets at the Tevatron have been interpreted as
being due to the exchange of two gluons which are in an overall color-singlet
state. We show that this simple picture involves unitarity violating
amplitudes. Unitarizing the gluon exchange amplitude leads to qualitatively
different predictions for the fraction of $t$-channel color singlet exchange
events in forward $qq$, $qg$ or $gg$ scattering, which better fit Tevatron
data.


title: Compositeness Test at the FMC with Bhabha Scattering

abstract:
  It is possible that quarks and/or leptons have substructure that will become
manifest at high energies. Here we investigate the limits on the muon
compositeness scale that could be obtained at the First Muon Collider using
Bhabha scattering. We study this limit as a function of the collider energy and
the angular cut imposed by the detector capability.


title: Non-universal Soft SUSY Breaking and Dark Matter

abstract:
  A brief review of non-universalities in the soft SUSY breaking sector of
supergravity grand unification is given. The effects of these
non-universalities on the analysis of event rates in neutralino nucleus
scattering are discussed. An analysis is also given of the implications of the
simultaneous imposition of proton stability and dark matter constraints. One
finds that these constraints put an upper limit on the gluino mass.


title:
One-Loop Corrections and All Order Factorization In Deeply Virtual
  Compton Scattering

abstract:
  We calculate the one-loop corrections to a general off-forward deeply-virtual
Compton process at leading twist for both parton helicity-dependent and
independent cases. We show that the infrared divergences can be factorized
entirely into off-forward parton distributions, even when one of the two
photons is onshell. We argue that this property persists to all orders in
perturbation theory. We obtain the next-to-leading order Wilson coefficients
for the general leading-twist expansion of the product of two electromagnetic
currents in the \overline{\rm MS} scheme.


title: Spectral representation for on-shell massless double box

abstract:
  A method is presented for obtaining the $\epsilon$-expansion for on-shell
massless scalar double-box diagram.


title: Proof of Factorization for Deeply Virtual Compton Scattering in QCD

abstract:
  We show that factorization holds for the deeply virtual Compton scattering
amplitude in QCD, up to power suppressed terms, to all orders in perturbation
theory. Furthermore, we show that the virtuality of the produced photon does
not influence the general theorem.


title: New String Excitations in the Two-Higgs Standard Model

abstract:
  We establish the existence of a static, classically stable string solution in
a region of parameters of the generic two-Higgs Standard Model. In an
appropriate limit of parameters, the solution reduces to the well-known soliton
of the O(3) non-linear sigma model.


title:
$\lambda\phi^4$ model and Higgs mass in standard model calculated by
  Gaussian effective potential approach with a new
  regularization-renormalization method

abstract:
  Basing on new regularization-renormalization method, the $\lambda\phi^4$
model used in standard model is studied both perturbatively and
nonperturbatively (by Gaussian effective potential). The invariant property of
two mass scales is stressed and the existence of a (Landau) pole is emphasized.
Then after coupling with the SU(2)$\times$U(1) gauge fields, the Higgs mass in
standard model (SM) can be calculated as $m_H\approx$138GeV. The critical
temperature ($T_c$) for restoration of symmetry of Higgs field, the critical
energy scale ($\mu_c$, the maximum energy scale under which the lower
excitation sector of the GEP is valid) and the maximum energy scale
($\mu_{max}$, at which the symmetry of the Higgs field is restored) in the
standard model are $T_c\approx$476 GeV, $\mu_c\approx 0.547\times 10^{15}$GeV
and $\mu_{\max}\approx 0.873 \times 10^{15}$ GeVv respectively.


title: The Higgs resonance in vector boson scattering

abstract:
  A heavy Higgs resonance is described in a representation-independent way
which is valid for the whole energy range of 2 -> 2 scattering processes,
including the asymptotic behavior at low and high energies. The low-energy
theorems which follow from to the custodial SU_2 symmetry of the Higgs sector
restrict the possible parameterizations of the lineshape that are consistent in
perturbation theory. Matching conditions are specified which are necessary and
sufficient to relate the parameters arising in different expansions. The
construction is performed explicitly up to next-to-leading order.


title:
QCD Perturbation Theory at Finite Temperature/Density and its
  Application

abstract:
  In order to describe properties of an equilibrated quark-gluon plasma, QCD at
finite temperature (and density) has to be considered. Besides lattice
calculations, which can be applied only to static quantities at zero density,
perturbative QCD has been used. At finite temperature, however, serious
problems such as infrared divergent and gauge dependent results have been
encountered. These difficulties can be (partially) avoided if one starts from
effective Green functions constructed by resumming a certain class of diagrams
(hard thermal loops). Within the last few years this improved perturbation
theory (Braaten-Pisarski method) turned out to be a powerful tool for computing
interesting quantities of the quark-gluon plasma phase. In the present talk a
basic introduction to the Braaten-Pisarski method is provided and its
applications and limits are reviewed. In particular, damping rates, the energy
loss of energetic partons, thermalization times, the viscosity of the
quark-gluon plasma, and the production of photons and dileptons are discussed.


title: Cosmology: Theory and Observations

abstract:
  The comparison of the Standard Cosmological Model (SCM) with astronomical
observations, i.e. theory versus experiment, and with the Minimal Standard
Model (MSM) in particle physics, i.e. theory versus theory, is discussed. The
main issue of this talk is whether cosmology indicates new physics beyond the
standard $SU(3)\times SU(2)\times U(1)$ model with minimal particle content.
The answer to this question is strongly and definitely "YES". New, yet unknown,
physics exists and cosmology presents very weighty arguments in its favor.


title: Threshold Resummation for Dijet Cross Sections

abstract:
  We construct dijet differential cross sections at large momentum transfer, in
which threshold logarithms have been summed to all orders in perturbation
theory. This extends previous work on heavy quark production, by treating
collinear singularities associated with hard, massless partons in the final
state. The resummed corrections enable us to define, in the sense of
factorization, the underlying color exchange mechanism. The influence of color
exchange on the resummed cross section is contained in the eigenvalues and
eigenvectors of an anomalous dimension matrix, which describes the
factorization of coherent soft gluons from the hard scattering. The precise
formulas depend on the partonic scattering angles and energies, as well as on
the method used to define the jets in the final state. For cone dijets at fixed
invariant mass, we find leading logarithmic corrections that, like those in the
Drell-Yan process, are positive, and which grow with increasing dijet invariant
mass. Other choices of dijet cross section can give, however, qualitatively
different behavior, even at leading logarithm.


title: Heavy-Quark Effective Theory and Weak Matrix Elements

abstract:
  Recent developments in the theory of weak decays of heavy flavours are
reviewed. Applications to exclusive semileptonic B decays, the semileptonic
branching ratio and charm counting, beauty lifetimes, and hadronic B decays are
discussed.


title: Flavour Changing Neutral Current Processes and CKM Phenomenology

abstract:
  Some selected topics in flavour changing neutral current processes in $B$
decays are discussed in the context of the Standard Model. The emphasis here is
on the determination of the CKM matrix elements from the ongoing and
forthcoming experiments. The topics discussed include: (i) CKM-allowed
radiative decays $B \to X_s + \gamma$, (ii) CKM-suppressed radiative decays $B
\to X_d + \gamma$, $B^\pm \to \rho^\pm + \gamma$ and $B^0 \to (\rho^0,\omega) +
\gamma$, (iii) $B^0 - \bar{B^0}$-mixings, and (iv) the Fleischer-Mannel bound
in $B \to K\pi$ decays.


title: Theories with Gauge-Mediated Supersymmetry Breaking

abstract:
  Theories with gauge-mediated supersymmetry breaking provide an interesting
alternative to the scenario in which the soft terms of the low-energy fields
are induced by gravity. These theories allow for a natural suppression of
flavour violations in the supersymmetric sector and have very distinctive
phenomenological features. Here we review their basic structure, their
experimental implications, and the attempts to embed them into models in which
all mass scales are dynamically generated from a single fundamental scale.


title: Bubbles in the supersymmetric standard model

abstract:
  We compute the tunneling probability from the symmetric phase to the true
vacuum, in the first order electroweak phase transition of the MSSM, and the
corresponding Higgs profiles along the bubble wall. We use the resummed
two-loop temperature-dependent effective potential, and pay particular
attention to the light stop scenario, where the phase transition can be
sufficiently strongly first order not to wipe off any previously generated
baryon asymmetry. We compute the bubble parameters which are relevant for the
baryogenesis mechanism: the wall thickness and $\Delta\beta$. The two-loop
corrections provide important enhancement effects, with respect to the one-loop
results, in the amount of baryon asymmetry.


title:
Top Quark Pair Production at Threshold -- Uncertainties and Relativistic
  Corrections

abstract:
  It is shown how nonrelativistic QCD (NRQCD) can be used to determine
next-to-next-to-leading order relativistic and short-distance contributions to
the total $t\bar t$ production cross section in the threshold regime at lepton
colliders. A recipe for the calculation of all such contributions for the total
photon mediated production cross section is presented and a review of the
already known Abelian next-to-next-to-leading results is given.


title: CP Violation in tau -> nu_tau + 3 pi

abstract:
  We discuss the ways to find CP violation in the decay of $\tau^\pm\to
\nu_\tau + 3\pi$ from unpolarized as well as polarized $\tau^\pm$.


title: Top Quark Pair Production at Higher Energies at the First Muon Collider

abstract:
  For a proper theoretical description of the top quark pair production cross
section at the First Muon Collider in the kinematic regime away from the
threshold the complete mass and energy dependence has to be taken into account.
Two-loop calculations for the photon mediated total cross section are reviewed.


title: Analysis of neutrino oscillation in three-flavor neutrinos

abstract:
  We analyzed the solar, terrestrial and atmospheric neutrinos experiments
using the three-flavor neutrino framework and got the allowed regions for
parameters (\Delta m_{12}^2, \sin^22\theta_{12}, \Delta m_{23}^2, \theta_{13},
\theta_{23}). In solar neutrino experiments, we got the large angle solution
(\Delta m_{12}^2, \sin^22\theta_{12})=(4x10^{-6}
  - 7x10^{-5}eV^2, 0.6 - 0.9) and small angle solution (3x10^{-6} -
1.2x10^{-5}eV^2, 0.003 - 0.01) for \theta_{13}=0^\circ - 20^\circ. From the
terrestrial and atmospheric neutrino experiments, we got the allowed regions
(\theta_{13}<4^\circ, 24^\circ<\theta_{23}<26^\circ) for \Delta m_{23}^2=2eV^2,
(\theta_{13}<4^\circ, 24^\circ<\theta_{23} <45^\circ) for \Delta
m_{23}^2=0.2eV^2 and (\theta_{13}<14^\circ, \theta_{23}=40^\circ) for \Delta
m_{23}^2=0.02eV^2. It seems that the large angle solution for (\Delta m_{12}^2,
\sin^22\theta_{12}) is favored than the small angle slution from the analysis
of zenith angle dependence in atmospheric neutrino sub-GeV experiment.


title: Double scattering on the nucleus in the perturbative QCD

abstract:
  In the hard pomeron model consequences are studied which follow from the
recently obtained form of the diffractive amplitude for the double scattering
on the nucleus and the related EMC effect at small $x$. It is shown that at
large $Q^2$ the double scattering contribution to the latter falls as
$Q^{-0.6338}$ and in all probability dominates the total effect.


title: On the diffraction in the perturbative QCD

abstract:
  In the framework of the hard pomeron model it is shown that at large $Q^2$
the diffractive contribution to the structure functions rises as $Q^{0.3362}$
and much slowlier than the total contribution rising as $Q$.


title: Long distance contributions in $D \to V \gamma$ decays

abstract:
  Using the factorization scheme for the nonleptonic $D \to V V_0$ weak
amplitudes, we classify all diagrams which arise in $D \to V \gamma$ decays and
calculate them with the help of the hybrid model which combines the heavy quark
effective theory and the chiral Lagrangian approach. Thus we determine the long
distance contribution to the amplitudes of Cabibbo allowed and Cabibbo
suppressed $D \to V\gamma$ decays. The calculation of the expected range of the
branching ratios of nine different $D \to V \gamma$ channels is compared with
results of other approaches. The present work establishes an increase of the
parity violating contribution in these decays in comparison with previous
analyses.


title: Cosmology of Light Moduli

abstract:
  In string/M-theory with a large compactification radius, some axion-like
moduli can be much lighter than the gravitino. Generic moduli in gauge-mediated
supersymmetry breaking models also have a mass far below the weak scale.
Motivated by these, we examine the cosmological implications of light moduli
for the mass range from the weak scale to an extremely small scale of order
10^{-26} eV, and obtain an upper bound on the initial moduli misalignment for
both cases with and without a late entropy production.


title: Gluon Spin in a Quark Model

abstract:
  We compute the gluon polarization $\Delta G$ and the gluon total angular
momentum $J_g$ in the Isgur-Karl quark model. Taking into account
self-interaction contributions, we obtain for both quantities a positive value
of about 0.24 at the model scale $\mu_0^2 \simeq 0.25$ GeV$^2$. This estimate
is reasonably close to the expectation from polarized deep inelastic scattering
analyses.


title: Two alternatives of spontaneous chiral symmetry breaking in QCD

abstract:
  Considering QCD in an Euclidean box, the mechanism of spontaneous breaking of
chiral symmetry (SB$\chi$S) is analyzed in terms of average properties of
lowest eigenstates of the Dirac operator. A formal analogy between the pion
decay constant and conductivity in disordered systems is established. It
follows that SB$\chi$S results from a subtle balance between the density of
Euclidean quark states and their mobility. SB$\chi$S can be realized either
with $<\bar q q > =0$, provided the low density of states is compensated by a
high mobility, or with a non-vanishing condensate, provided the mobility is
suppressed. It is conjectured that the first case corresponds to extended
whereas the latter case to (weakly) localized quark states.


title: Strange / anti-strange asymmetry in the nucleon sea

abstract:
  We analyze the non-perturbative structure of the strange sea of the nucleon
within a meson cloud picture. In a low $Q^2$ approach in which the nucleon is
viewed as a three valon bound state, we evaluate the probability distribution
of an in-nucleon Kaon-Hyperon pair in terms of splitting functions and
recombination. The resulting kaon and hyperon probability densities are
convoluted with suitable strange distributions inside the meson and baryon in
order to obtain non-perturbative contributions to the strange sea of the
nucleon. We find a structured strange/anti-strange asymmetry, displaying a
clear excess of quarks (anti-quarks) for large (small) momentum fractions


title: Long-distance final-state interactions and J/psi decay

abstract:
  To understand the short-distance vs long-distance final-state interactions,
we have performed a detailed amplitude analysis for the two-body decay, J/psi
into vector and pseudoscalar mesons. The current data favor a large relative
phase nearly 90 degrees between the three-gluon and one-photon decay
amplitudes. The source of this phase is apparently in the long-distance
final-state interaction. Nothing anomalous is found in the magnitudes of the
three-gluon and one-photon amplitudes. We discuss implications of this large
relative phase in the weak decay of heavy particles.


title:
An Investigation of Uncertainties in the QCD NLO Predictions of the
  Inclusive Jet Cross Section in pbarp Collisions at sqrt(s) = 1.8 TeV and 630
  GeV

abstract:
  Uncertainties in the NLO calculation of the inclusive jet cross section due
to the choice of renormalization scale, parton distribution functions and
clustering algorithm are explored. These are found to be similar in size to the
current experimental uncertainties of the measured inclusive jet cross section
at DZero and CDF.


title: Magnetic Fields from the Electroweak Phase Transition

abstract:
  I review some of the mechanisms through which primordial magnetic fields may
be created in the electroweak phase transition. I show that no magnetic fields
are produced initially from two-bubble collisions in a first-order transition.
The initial field produced in a three-bubble collision is computed. The
evolution of fields at later times is discussed.


title: On unusual interactions of the (1/2,0)+(0,1/2) particles

abstract:
  We continue to study the `fermion -- 4-vector potential' interactions in the
framework of the McLennan-Case construct which is a reformulation of the
Majorana theory of the neutrino. This theory is shown after applying
Majorana-like anzatzen to give rise to appearance of unusual terms as
\vec\sigma \cdot [\vec A \times \vec A^\ast ], which were recently discussed in
non-linear optics.


title: High Energy Photon-Photon and Electron-Photon Collisions

abstract:
  The advent of a next linear $e^\pm e^-$ collider and back-scatterd laser
beams will allow the study of a vast array of high energy processes of the
Standard Model through the fusion of real and virtual photons and other gauge
bosons. As examples, I discuss virtual photon scattering $\gamma^* \gamma^* \to
X$ in the region dominated by BFKL hard Pomeron exchange and report the
predicted cross sections at present and future $e^\pm e^-$ colliders. I also
discuss exclusive $\gamma \gamma$ reactions in QCD as a measure of hadron
distribution amplitudes and a new method for measuring the anomalous magnetic
and quadrupole moments of the $W$ and $Z$ gauge bosons to high precision in
polarized electron-photon collisions.


title: Properties of the QCD vacuum in the dual Ginzburg-Landau theory

abstract:
  We study the properties of the QCD vacuum in the dual Ginzburg-Landau theory,
where QCD-monopole condensation leads to the linear confinement potential.
Using the effective potential, we find monopole dominance for chiral-symmetry
breaking. The effective mass of off-diagonal (charged) gluons is estimated as
$M_{ch} \simeq 1.31$ GeV. The gluon condensate is calculated as
$<\frac{\alpha_{s}}{\pi}G^2 > = (344 MeV)^4$.


title:
An Upper Bound on the Higgs Boson Mass from a Positivity Condition on
  the Mass Matrix

abstract:
  We impose the condition that the eigenvalues of the mass matrix in the
shifted Lagrangian density be positive at \phi=\phi_{0}, the vacuum expectation
value of the scalar field. Using the one-loop effective potential of the
standard model, this condition leads to an upper bound on the Higgs boson mass
m_{H}: m_{H}<230GeV, for a top quark mass of 175GeV.


title: A possible origin of the endpoint anomaly in tritium beta-spectrum

abstract:
  The influence of the residual T atoms appearing after the decay of T_2
molecule on the beta-spectrum shape is considered. Recent experiments performed
in Mainz, Troitsk, and Livermore are briefly reviewed from this viewpoint.
Aspects connected with the possible time dependent change of the tritium source
composition are discussed.


title: Nuclear Shadowing Effects on Prompt Photons at RHIC and LHC

abstract:
  The transverse momentum distribution of prompt photons coming from the very
early phase of ultrarelativistic heavy ion collisions for the RHIC and LHC
energies is calculated by means of perturbative QCD. We calculate the single
photon cross section ($A+B\to \gamma +X$) by taking into account the partonic
sub processes $q+ \bar{q}\to \gamma +g$ and $q+g\to\gamma +q$ as well as the
Bremsstrahlung corrections to those processes. We choose a lower momentum
cut-off $k_0 =2$ GeV separating the soft physics from perturbative QCD. We
compare the results for those primary collision with the photons produced in
reactions of the thermalized secondary particles, which are calculated within
scaling hydrodynamics. The QCD processes are taken in leading order. Nuclear
shadowing corrections, which alter the involved nuclear structure functions are
explicitly taken into account and compared to unshadowed results. Employing the
GRV parton distribution parametrizations we find that at RHIC prompt
QCD-photons dominate over the thermal radiation down to transverse momenta $k_T
\approx 2$ GeV. At LHC, however, thermal radiation from the QGP dominates for
photon transverse momenta $k_T \leq 5$ GeV, if nuclear shadowing effects on
prompt photon production are taken into account.


title: An extension of the Statistical Bootstrap Model to include Strangeness

abstract:
  We extend the Statistical Bootstrap Model (SBM) in order to describe hadronic
systems which carry strangeness. We establish that the hadronic phase can exist
only in a region of the three-dimensional space of temperature, up-down and
strange chemical potentials, which is bounded by a critical critical surface.
We first employ the usual version of the SBM, which corresponds to the value 2
of the exponent which determines the asymptotic fall-off of the mass spectrum
and impose strangeness neutrality in order to obtain the relation between the
temperature and the chemical potentials of the quarks. We find an unphysical
behaviour of the strange chemical potential near the critical surface.
Subsequently, we study another version of SBM where the value of the exponent
equals 4 and we are led to a realistic as well as acceptable behaviour. In this
case we are also able to relate the parameter of the model, the critical
temperature at zero strange chemical potential) with the MIT bag constant B.


title: CP violation in the top-quark system through light squarks

abstract:
  We study a decay rate asymmetry of the top quark in the supersymmetric
standard model, taking into account the constraints from the electric dipole
moments of the neutron and the electron. One CP-violating phase contained in
the mass-squared matrices of squarks and sleptons is allowed to have an
unsuppressed value, even if their masses are of order 100 GeV. Sizable $CP$
violation could then occur in the production and decay of the top quark through
interactions with top squarks. The asymmetry between the widths for the decays
$t\to bW^+$ and $\bar t\to \bar bW^-$ can be of order $10^{-3}$, which will
possibly be detectable in the near future.


title: Flavor structure of the octet magnetic moments

abstract:
  We use the chiral quark-soliton model to identify all symmetry breaking terms
linear in $m_{s}$ and investigate the strange magnetic moment in a
``model-independent'' way. Assuming hedgehog symmetry and employing the
collective quantization, we obtain the most general expression for the
flavor-singlet and flavor-octet magnetic moments in terms of seven independent
parameters. Having fitted these parameters to the experimental magnetic moments
of the octet baryons, we show that the strange magnetic moment turns out to be
positive. The best fit obtained by minimizing $\chi^2$ assuming 15% theoretical
accuracy yields: $\mu^{({\rm s})}_{N} = (0.41 \pm 0.18) \mu_{N}$.


title: Baryogenesis from top squark transport

abstract:
  Baryon asymmetry of the universe is generated in the supersymmetric standard
model (SSM) through the charge transport mechanism mediated by top squarks.
Necessary CP violation originates from a complex phase contained in
mass-squared matrices of squarks and sleptons. This complex phase also gives
contributions to the electric dipole moments (EDMs) of the neutron and the
electron. The amount of induced baryon asymmetry is consistent with its
observed value within reasonable ranges of SSM parameters. The EDMs are
predicted to be slightly smaller than their experimental upper limits.


title: The form factors of the nucleon at small momentum transfer

abstract:
  We study the low energy expansion of the nucleon's electroweak form factors
in the framework of an effective chiral Lagrangian including pions, nucleons
and the $Delta (1232)$. We work to third order in the so-called small scale
expansion and compare the results with the ones previously obtained in the
chiral expansion. In addition, these calculations serve as a first exploratory
study of renormalization and decoupling within the small scale expansion.


title: Long-distance contributions to the K_L --> mu+ mu- decay width

abstract:
  The dispersive two-photon contribution to the K_L --> mu+ mu- decay amplitude
is analyzed, using chiral perturbation theory techniques and large-N_C
considerations. A consistent description of the decays Pi^0 --> e+ e-, Eta -->
mu+ mu- and K_L --> mu+ mu- is obtained. As a byproduct, one predicts Br(Eta
--> e+ e-) = (5.8+-0.2) x 10^-9 and Br(K_L --> e+ e-) = (9.0+-0.4) x 10^-12.


title: Inflation in softly broken Seiberg-Witten models

abstract:
  In a recent paper we proposed a new model of inflation based on the
soft-breaking of N=2 supersymmetric SU(2) Yang-Mills theory. The advantage of
such a model is the fact that we can write an exact expression for the
effective scalar potential, including perturbative and non-perturbative
effects. We find that the scalar condensate that plays the role of the inflaton
can drive a long period of cosmological expansion in the weak coupling Higgs
region, and end inflation in the strong coupling monopole region, where
reheating takes place. The model predicts the right amount of temperature
anisotropies in the microwave background, a precise spectral tilt, $n=0.91$,
and negligible gravitational wave perturbations.


title:
A Study of the Polarized Structure Function g_1^p(x,Q^2) and the
  Polarized Gluon Distribution Delta g(x,Q^2) at HERA

abstract:
  We present estimates of possible data on spin-dependent asymmetries in
inclusive scattering of high energy polarized electrons by high energy
polarized protons at HERA with their statistical errors and discuss systematic
errors. We show that these data will provide important information on the low-x
behavior of the polarized structure function g_1, and will reduce the
uncertainty in the determination of the first moment of the polarized gluon
distribution Delta g(x,Q^2) obtained from the QCD analysis of g_1 in NLO.
Furthermore, using asymmetries for di-jet events from a polarized HERA would
substantially reduce the uncertainty in the shape of Delta g(x,Q^2). Using the
information on Delta g(x,Q^2) from the di-jet analysis in conjunction with the
NLO QCD analysis of g_1 will provide an accurate determination of Delta
g(x,Q^2) and its first moment.


title:
Inclusion of tau anomalous magnetic and electric dipole moments in the
  KORALZ Monte Carlo

abstract:
  We describe modifications made to KORALZ version 4.03 in order to allow for
anomalous magnetic and electric dipole moments of the tau. We discuss the
verification of the method at LEP 1 energies.


title: Pomeron Non Factorization in Diffractive Scattering at HERA

abstract:
  Pomeron non factorization for the diffractive scattering is considered and an
analysis of experimental data is performed with different cuts in the momentum
fraction $\xi$. The results of the analysis are compared with the breaking
predicted in the Genovese-Nikolaev-Zakharov model.


title: Modulino as natural candidate for a sterile neutrino

abstract:
  We discuss the possible generation of R-parity violating bilinear terms $
\mu_i\bar L_i H_2$ in both cases of gravity and gauge mediated supersymmetry
breaking. Some phenomenological aspects are reviewed. In particular for
scenario where $ \mu_i$ depend on the vacuum expectation values of some fields
$S$, its fermionic partner $\tilde S$ plays the role of a sterile neutrino.
This situation is quiet generic in the case of models arising from M-theory
where $S$ is a modulus field. Observable effects are expected to be seen if the
mass and mixing of $\tilde S$ with active neutrinos lie in an interesting
region of parameters. This is naturally the case in gauge mediated
supersymmetry breaking and some class of no-scale supergravity models where the
gravitino mass is very small. For models with gravitino mass $m_{3/2}\sim$ TeV,
we discuss the possibility that the modulino mass is of the order of
$m^2_{3/2}/M_{Pl}$.


title:
The Collision Energy Dependence of Dijet Cross Sections as a Probe of
  BFKL Physics

abstract:
  The dependence of the subprocess cross section for dijet production at fixed
transverse momentum on the (large) rapidity separation Delta y of the dijets
can be used to test for `BFKL physics', i.e. the presence of higher--order
(alphas log(Delta y)^n contributions. Unfortunately in practice these subtle
effects are masked by the additional, stronger dependence arising from the
parton distributions. We propose a simple ratio test using two different
collider energies n which the parton distribution dependence largely cancels.
Such a ratio does distinguish between the `asymptotic' analytic BFKL and
lowest-order QCD predictions. However, when subasymptotic effects from overall
energy-momentum conservation are included, the BFKL predictions for present
collider energies change qualitatively. In particular, the real gluon emission
contributions to the BFKL cross section are suppressed. The proposed ratio
therefore provides an interesting laboratory for studying the interplay of
leading-logarithm and kinematic effects.


title:
Study of the resummation of chiral logarithms in the exponentiated
  expression for the pion form factor

abstract:
  From the properties of analyticity and unitarity it has been recently
obtained an exponentiated expression for the pion form factor. In this work I
show the validity of this expression comparing its order p^6 term with the one
exactly calculated in ChPT.


title:
GUT baryogenesis after preheating: numerical study of the production and
  decay of X-bosons

abstract:
  We perform a fully non-linear calculation of the production of supermassive
Grand Unified Theory (GUT) $X$ bosons during preheating, taking into account
the fact that they are unstable with a decay width $\Gamma_X$. We show that
parametric resonance does not develop if $\Gamma_X$ is larger than about
$10^{-2} m_X$. We compute the nonthermal number density of superheavy bosons
produced in the preheating phase and demonstrate that the observed baryon
asymmetry may be explained by GUT baryogenesis after preheating if $\Gamma_X$
is smaller than about $10^{-3} m_X$.


title: Larger Domains from Resonant Decay of Disoriented Chiral Condensates

abstract:
  The decay of disoriented chiral condensates into soft pions is considered
within the context of a linear sigma model. Unlike earlier analytic studies,
which focused on the production of pions as the sigma field rolled down toward
its new equilibrium value, here we focus on the amplification of
long-wavelength pion modes due to parametric resonance as the sigma field
oscillates around the minimum of its potential. This process can create larger
domains of pion fluctuations than the usual spinodal decomposition process, and
hence may provide a viable experimental signature for chiral symmetry breaking
in relativistic heavy ion collisions; it may also better explain physically the
large growth of domains found in several numerical simulations.


title:
Electromagnetic form factors in the J/\psi mass region: The case in
  favor of additional resonances

abstract:
  Using the results of our recent analysis of e^+e^- annihilation, we plot the
curves for the diagonal and transition form factors of light hadrons in the
time-like region up to the production threshold of an open charm quantum
number. The comparison with existing data on the decays of J/\psi into such
hadrons shows that some new resonance structures may be present in the mass
range between 2 GeVand the J/\psi mass. Searching them may help in a better
understanding of the mass spectrum in both the simple and a more sophisticated
quark models, and in revealing the details of the three-gluon mechanism of the
OZI rule breaking in K\bar K channel.


title: The Spin Symmetry of Heavy Baryons in the Framework of the B.S. Equation

abstract:
  We construct the B.S. equation for baryons. The most general form of the B.S.
wave function is given. In the heavy quark limit we show clearly that the spin
symmetry exists in heavy baryon states.


title: The Cheshire Cat revisited

abstract:
  The concept of effective field theory leads in a natural way to a
construction principle for phenomenological sensible models known under the
name of the Cheshire Cat Principle. We review its formulation in the chiral bag
scenario and discuss its realization for the flavor singlet axial charge.
Quantum effects inside the chiral bag induce a color anomaly which requires a
compensating surface term to prevent breakdown of color gauge invariance. The
presence of this surface term allows one to derive in a gauge-invariant way a
chiral-bag version of the Shore-Veneziano two-component formula for the
flavor-singlet axial charge of the proton. We show that one can obtain a
striking Cheshire-Cat phenomenon with a negligibly small singlet axial charge.


title: New Results of the HEGRA Air Shower Detector Complex

abstract:
  Recent highlight results obtained with the air shower detector complex HEGRA
at the Canary island La Palma are presented. Observations and searches for
gamma sources above an energy of 500 GeV are covered, where special emphasis is
put on the recent flaring activities of the Blazar Mkn 501. A second main
research topic of the experiment is the measurement of the energy spectrum and
the elemental composition of the charged cosmic rays. Data covering the energy
region of the "knee" around 3 PeV are presented.


title: Present and Future Searches for Leptoquarks

abstract:
  We review the present seach for scalar leptoquarks and the potential of the
CERN Large Hadron Collider (LHC) to unravel the existence of first generation
leptoquarks. Talk given by O. J. P. Eboli at the International Workshop on
"Physics Beyond the Standard Model: from Theory to Experiment", Valencia, 1997.


title: Symmetry Non-restoration at High Temperature

abstract:
  We discuss the (non)-restoration of global and local symmetries at high
temperature. First, we analyze a two-scalar model with $Z_2 \times Z_2$
symmetry using the exact renormalization group. We conclude that inverse
symmetry breaking is possible in this kind of models within the perturbative
regime. Regarding local symmetries, we consider the $SU(2) \otimes U(1)$ gauge
symmetry and focus on the case of a strongly interacting scalar sector.
Employing a model-independent chiral Lagrangian we find indications of symmetry
restoration.


title: Fluid Dynamical Description of the Chiral Transition

abstract:
  We investigate the dynamics of the chiral transition in an expanding
quark-anti-quark plasma. The calculations are made within a linear sigma model
with explicit quark and antiquark degrees of freedom. We solve numerically the
classical equations of motion for chiral fields coupled to the fluid dynamical
equations for the plasma. Fast initial growth and strong oscillations of the
chiral field and strong amplification of long wavelength modes of the pion
field are observed in the course of the chiral transition.


title: Comments on the review of CP Violation in the Particle Data Book

abstract:
  Rephasing invariant formalism for the $K^0-\bar K^0$ system is recommended
for the Particle Data Group. This formalism is accurate and prevents possible
errors in generalizing the formalism to other systems, as well as in using CKM
matrices not included in the Particle Data Book.


title: Qunatum Number Exotic Mesons and Large N QCD

abstract:
  Exotic mesons with quantum numbers of a hybrid ($\bar{q} q g$) such as
$J^{PC} = 1^{-+}$are shown to exist as narrow resonant states in the large
$N_c$ limit of QCD. The width of these states is proportional to $1/N_c$.
Possible phenomenological implications for the world of $N_c=3$ are discussed.


title: Determining the Coupling of a Higgs Boson to $ZZ$ at Linear Colliders

abstract:
  We demonstrate that, at a 500 GeV e+e- collider, inclusion of the $ZZ$-fusion
process for production of a light standard-model-like Higgs boson can
substantially increase the precision with which the $ZZh$ coupling can be
determined (using the model-independent recoil mass technique) as compared to
employing only $Zh$ associated production.


title:
Using Collider Event Topology in the Search for the Six-Jet Decay of Top
  Quark-Antiquark Pairs

abstract:
  We investigate the use of the event topology as a tool in the search for the
six-jet decay of top-pair production in proton-antiproton collisions at 1.8
TeV. Modified Fox-Wolfram "shape" variables, H_i, are employed to help
distinguish the top-pair signal from the ordinary QCD multi-jet background. The
H's can be constructed directly from the calorimeter cells or from jets. Events
are required to lie in a region of H-space defined by L_i < H_i < R_i for
i=1,...,,6, where the left, L_i, and right, R_i, cuts are determined by a
genetic algorithm (GA) procedure to maximize the signal over the square root of
the background. We are able to reduce the background over the signal to less
than a factor of 100 using purely topological methods without using jet
multiplicity cuts and without the aid of b-quark tagging.


title: The Contribution of Reggeon in Charge Exchange Processes

abstract:
  We discuss in this paper The experimental results on maximum psedo-rapidity
$\eta_{max}$ distribution in the charge exchange process $e+p\to e+n+X$ in ZEUS
Collaboration at HERA. We calculate the contributions of \regg ($\rho$-Reggeon
associated with $\rho$ meson) from regge phenomenology and $\pi^{+}$-exchange
from pion cloud model. The results show that neither the \regg-exchange nor the
pion cloud model alone can explain the experimental data well, but after
considering both these two processes together, by using Monte Carlo simulation,
a good agreement between theoretical results and experimental data is found.
This means that in discussing the large rapidity gap phenomena in deep
inelastic scattering, both of the two processes play substantial role.


title:
Connecting Experiment with Theory: A Model-Independent Parameterization
  of Neutrino Oscillations

abstract:
  Many experiments are currently looking for evidence of neutrino mass in the
form of neutrino oscillations. Oscillation probabilities are non-linear
functions of the neutrino mixing matrix elements, so most comparisons of data
to theory are based on simplifying models of the mixing matrix. We begin this
dissertation with a review of neutrino interactions and a few of the popular
models describing neutrino masses and mixing. Next we present our
model-independent description of neutrino oscillations and derive the
predictions of various models in terms of our new ``box'' parameterization.
Finally, we use our boxes to find mixing matrices consistent with existing
neutrino data. As more definitive data becomes available, these solutions will
probably need to be adjusted; when such a need arises, our box notation will
provide a convenient method for finding new solutions.


title: Dilepton emission from an equlibrating non-abelian plasma

abstract:
  We study dilepton production from a thermally equilibrating quark-gluon
plasma expected to be formed in ultra relativistic heavy-ion collisions. The
pre-equilibrium dynamics of quark-gluon plasma is studied within the color
flux-tube model by solving non-abelian relativistic transport equations. This
dilepton rate crucially depends on the collision time of the plasma. The
results are compared with the Drell-Yan productions. We suggest that a
measurement of this rate at RHIC and LHC will determine the initial field
energy density.


title: Energy Scale and Coherence Effects in small-x Equations

abstract:
  I consider the next-to-leading,high-energy cluster expansion of large-k
double-jet production in QCD, and I determine the corresponding one-loop quark
and gluon impact factors, for a self-consistent energy scale. The result shows
that coherent angular ordering of emitted gluons holds for hard emission also,
and singles out a scale which is essentially the largest virtuality in the
process. Both remarks are relevant for the precise deter- mination of the BFKL
kernel at the next-to-leading level.


title: Chargino Pair Production at CERN LEP II

abstract:
  Charginos are expected to be the lightest observable supersymmetric particles
in many of the supersymmetric models. In the scenario that lighter charginios
are pair-produced at CERN LEP II, we present a straightforward procedure for
determining the SUSY parameters, $\tan\beta$, $M_2$, $\mu$, and the electron
sneutrino mass $m_{\tilde{\nu}}$ up to a four-fold discrete ambiguity, although
a large number of unknown SUSY parameters are involved in chargino decays.


title: On the QCD analysis of Jet Broadening

abstract:
  The perturbative all-order analysis of the jet-broadening B-distribution in
the small-B region is carried out with single-logarithmic accuracy, which
requires the control of both the sum of the moduli and the modulus of the sum
of the transverse momenta of soft gluons. We confirm the master equation for
the B-distribution derived by Catani, Turnock and Webber (CTW). Proper
treatment of quark recoil is necessary at this accuracy. This effect was
neglected in the CTW solution. We show that the answer can be expressed in
terms of the CTW result but evaluated at a properly rescaled B value.


title:
Second order QCD contributions to polarized spacelike and timelike
  processes

abstract:
  We will give an outline of the computation of the QCD corrections to the spin
structure function g_1(x,Q^2) and the spin fragmentation function g_1^H(x,Q^2)
which are measured in deep inelastic electron-proton scattering and in
electron-positron annihilation respectively. In particular we show how to deal
with the gamma_5-matrix and the Levi-Civita tensor, appearing in the amplitudes
of the parton subprocesses, when the method of N-dimensional regularization is
used.


title: Obtaining K to pi pi from Off-Shell K to pi Amplitudes

abstract:
  We properly define off-shell $K\to\pi$ transition amplitudes and use them to
extract information for on-shell $K\to\pi\pi$ amplitudes within Chiral
Perturbation Theory. At order $p^2$ in the chiral expansion all three
parameters of weak interaction can be determined. At order $p^4$ we are able to
fix eleven additional constants out of thirteen contributing to off-shell
$K\to\pi$ transitions, which leaves four undetermined constants in the on-shell
$K\to\pi\pi$ amplitudes. All ${\cal O}(p^4)$ contributions have been exactly
derived with $m_\pi^2\ne 0$. We finally discuss the weak mass term issue and
find contributions to on-shell $\Delta S=\pm 1$ Kaon decays, in particular to
transitions like $K_L \to \gamma \gamma$, $K_L \to \mu^+ \mu^-$ and $K_S \to
\pi^0 \gamma \gamma$ at the lowest non-zero order.


title: Boxing with Neutrino Oscillations

abstract:
  We develop a model-independent "box" parameterization of neutrino
oscillations. Oscillation probabilities are linear in these new parameters, so
measurements can straightforwardly determine the box parameters which can then
be manipulated to yield magnitudes of mixing matrix elements. We examine the
effects of unitarity On the box parameters and reduce the number of parameters
to the minimum set. Using the box algebra, we show that CP-violation may be
inferred from measurements of neutrino flavor mixing even when the oscillatory
factor has averaged. The framework presented here will facilitate general
analyses of neutrino oscillations among $n\ge 3$ flavors.


title: Photoproduction of h_c

abstract:
  Using the NRQCD factorization formalism, we calculate the total cross section
for the photoproduction of h_c mesons. We include color-octet and color-singlet
mechanisms as well as next-to-leading order perturbative QCD corrections. The
theoretical prediction depends on two nonperturbative matrix elements that are
not well determined from existing data on charmonium production. For reasonable
values of these matrix elements, the cross section is large enough that the h_c
may be observable at the E831 experiment and at the HERA experiments.


title:
Signals of a superlight gravitino at hadron colliders when the other
  superparticles are heavy

abstract:
  If the gravitino (G) is very light and all the other supersymmetric particles
are above threshold, supersymmetry may still be found at colliders, by looking
at processes with only gravitinos and ordinary particles in the final state. We
compute here the cross-sections for some distinctive signals at hadron
colliders: photon plus missing energy, induced by (q antiquark -> G G photon),
and jet plus missing energy, induced by (q antiquark -> G G g), (q g -> G G q),
and (g g -> G G g). From the present Tevatron data, we estimate the bound
m_{3/2} > 2.3 10^-5 eV on the gravitino mass, corresponding to the bound
sqrt{F} > 310 GeV on the supersymmetry-breaking scale. We foresee that the
upgraded Tevatron and the LHC will be sensitive to values of m_{3/2} up to 4.0
10^-5 eV and 6.2 10^-4 eV, corresponding to sqrt{F} up to 410 GeV and 1.6 TeV,
respectively.


title: An Analytic Extension of the $\bar{MS}$ Renormalizaton Scheme

abstract:
  The conventional definition of the running coupling $\alpha_{\bar{MS}}(\mu)$
in quantum chromodynamics is based on a solution to the renormalization group
equations which treats quarks as either completely massless at a
renormalization scale $\mu$ above their thresholds or infinitely massive at a
scale below them. The coupling is thus nonanalytic at these thresholds. In this
paper we present an analytic extension of $\alpha_{\bar{MS}}(\mu)$ which
incorporates the finite-mass quark threshold effects into the running of the
coupling. This is achieved by using a commensurate scale relation to connect
$\alpha_{\bar{MS}}(\mu)$ to the physical $\alpha_V$ scheme at specific scales,
thus naturally including finite quark masses. The analytic-extension inherits
the exact analyticity of the $\alpha_V$ scheme and matches the conventional
$\bar {MS}$ scheme far above and below mass thresholds. Furthermore just as in
$\alpha_V$ scheme, there is no renormalization scale ambiguity, since the
position of the physical mass thresholds is unambiguous.


title: Probing Physics at Short Distances with Supersymmetry

abstract:
  We discuss the prospect of studying physics at short distances, such as
Planck length or GUT scale, using supersymmetry as a probe. Supersymmetry
breaking parameters contain information on all physics below the scale where
they are induced. We will gain insights into grand unification (or in some
cases string theory) and its symmetry breaking pattern combining measurements
of gauge coupling constants, gaugino masses and scalar masses. Once the
superparticle masses are known, it removes the main uncertainty in the analysis
of proton decay, flavor violation and electric dipole moments. We will be able
to discuss the consequence of flavor physics at short distances quantitatively.


title: Quark Orbital Motion in the Nucleon

abstract:
  An unified scheme for describing both spin and orbital motion in
symmetry-breaking chiral quark model is suggested. The analytic results of the
spin and orbital angular momenta carried by different quark flavors in the
nucleon are given. The quark spin reduction due to spin-flip in the chiral
splitting processes is compensated by the increase of the orbital angular
momentum carried by the quarks and antiquarks. The sum of both spin and orbital
angular momenta in the nucleon is 1/2, if the gluons and other degrees of
freedom are neglected. The same conclusion holds for other octet and decuplet
baryons. Possible modification and application are briefly discussed.


title: Thermal Gauge Theory, Effective Action and Z(N) Symmetry

abstract:
  One of the salient features of high temperature gluodynamics is the Z(N)
groundstate degeneracy, key to the understanding of the transition. On the
other hand impressive progress has been obtained with effective theories, that
seemingly lack Z(N) symmetry. We give a simple unified desciption of the two.
As a very useful byproduct we get a natural infrared regulator and show its
expediency by calculating the next to leading order in the Debye mass. Higher
order corrections to bulk free energy and domainwall surface tension are
discussed.


title:
Radiative Higgs Boson Decays H\to f\bar{f}\gamma Beyond the Standard
  Model

abstract:
  Neutral Higgs boson radiative decays of the form h_0, H, A \to
f\bar{f}\gamma, in the light fermion limit $m_f->0, are calculated in the two
Higgs doublet model at one-loop level. Comparisons with the calculation within
the standard model are given, which indicates that these two models are
distinguishable in the decay mode fermion-antifermion -photon. Our results show
that the concerned process may stand as an implement to identify the Higgs
belongings in case there is a intermediate mass Higgs detected.


title:
Diffractive J/psi production as a probe of the gluon component in the
  Pomeron

abstract:
  Presented here is a study of the large p_T J/psi production in hard
diffractive process by the pomeron exchange at the Fermilab Tevatron. We find
that this process (p\bar p \to p+J/psi+X) can be used to probe the gluon
content of the pomeron and to measure the gluon fraction of the pomeron. And
the diffractive direct J/psi production can also provide another crucial test
for the color-octet fragmentation mechanism. Using the renormalised pomeron
flux factor D\approx 1/9, the single diffractive J/psi production cross section
at large p_T (\geq 8GeV) is found to be of order of 0.01 nb, and the ratio of
the single diffractive to the non-diffractive J/psi production is 0.65\pm 0.15%
for the gluon fraction f_g=0.7\pm 0.2.


title:
Gluon fragmentation to $^3D_J$ quarkonium and test of color-octet
  production mechanism

abstract:
  We report the recent progress in the studies of D-wave heavy quarkonia
production from gluon fragmentation at the Tevatron and in Z^0 decays, and the
D-wave charmonia production in B decays. We show that the color-octet
contributions are of crucial importance to the production of D-wave quarkonia.
Signals, as strong as that for J/\psi and \psi^\prime, should be seen for the
D-wave charmonium in the processes. These will provide a test of the
color-octet production mechanism.


title: What can we learn from b->s gamma?

abstract:
  We review some recent theoretical progress in the understanding of weak
radiative B meson decay, and discuss the implications of present and improved
measurements of b -> s gamma for supersymmetric models.


title: QCD Properties of Hot/Dense Matter

abstract:
  In the introduction, we will discuss the symmetries of QCD, its breaking in
the physical vacuum and its restoration at finite temperature and/or density.
Then we will discuss what exact relations can be made between chiral symmetry
restoration and the imaginary part of the vector vector correlation function,
which is directly related to the dilepton spectrum coming from a hot and/or
dense medium. Finally, we will focus on the vector meson pole appearing in the
imaginary part and discuss results on how the shape changes using QCD sum rules
in medium. In particular, we will discuss three characteristic changes of the
vector meson peaks; namely, shift of the peak position, increase of its width
and the dispersion effect due to the breaking of Lorentz invariance in medium.


title:
A Test of $\numunux$ Oscillations and determination of the $\Delta m^2$
  parameter of Atmospheric Neutrinos using the $L/E$ method

abstract:
  We point out that the measurement of the $L/E$ distribution of atmospheric
neutrino events with sufficient resolution in order to observe the
characteristic modulations of neutrino oscillations would provide a unique way
to test the $\numunux$ oscillations nature of the atmospheric neutrino anomaly
in the parameter range $5\times 10^{-4} < \Delta m^2 < 2\times 10^{-3}\rm\
eV^2$. With an integrated exposure of a few tens of kiloton-year, this method
can cover the lower part of the $\Delta m^2$ region of the currently allowed
atmospheric neutrino solution and is therefore complementary to the one
explorable with planned long-baseline neutrino beam experiments. We stress that
experimentally this method relies on the ability to measure high energy muons
($E_\mu>5\rm GeV$). A large magnetized calorimeter of several kilotons would be
ideally suited for this measurement. The existing LEP detectors augmented with
atmospheric neutrino triggers could also be used to perform such a study.


title: Neutrino Masses and Mixing from Supersymmetric Inflation

abstract:
  A supersymmetric model based on a left-right symmetric gauge group is
proposed where hybrid inflation, baryogenesis and neutrino oscillations are
linked.This scheme, supplemented by a familiar ansatz for the neutrino Dirac
masses and mixing of the two heaviest families and with the MSW resolution of
the solar neutrino puzzle, implies that $m_{\nu_{\tau}}$ lies between 1 and 9
eV. The mixing angle $\theta_{\mu \tau}$ is predicted to lie in a narrow range
which will be partially tested by the Chorus/Nomad experiment.


title: A_{LT} in the polarized Drell-Yan process at RHIC and HERA energies

abstract:
  We present a leading order (LO) estimate for the longitidinal-transverse spin
asymmetry (A_{LT}) in the nucleon-nucleon polarized Drell-Yan process at RHIC
and HERA-$\vec{N}$ energies in comparison with A_{LL} and A_{TT}. A_{LT}
receives contribution from g_1, the transversity ditribution h_1, and the
twist-3 distributions g_T and h_L. For the twist-3 contribution we use the bag
model prediction evolved to a high energy scale by the large-N_c evolution
equation. We found that A_{LT} (normalized by the asymmetry in the parton
level) is much smaller than the corresponding A_{TT}. Twist-3 contribution
given by the bag model also turned out to be negligible.


title:
Approximate Sum Rules of CKM Matrix Elements from Quasi-Democratic Mass
  Matrices

abstract:
  To extract sum rules of CKM matrix elements, eigenvalue problems for
quasi-democratic mass matrices are solved in the first order perturbation
approximation with respect to small deviations from the democratic limit. Mass
spectra of up and down quark sectors and the CKM matrix are shown to have clear
and distinctive hierarchical structures. Numerical analysis shows that the
absolute values of calculated CKM matrix elements fit the experimental data
quite well. The order of the magnitude of the Jarlskog parameter is estimated
by the relation $|J| \approx \sqrt{2}(m_c/m_t + m_s/m_b)|V_{us}|^2|V_{cb}|/4$.


title: Flavour Physics

abstract:
  In these four lectures I review the theory and phenomenology of weak decays
of quarks, and their r\^ole in the determination of the parameters of the
Standard Model of particle physics, in testing subtle features of the theory
and in searching for signatures of new physics. Attempts to understand
CP-violation in current and future experiments is discussed.


title: Thermodynamics of the \phi^4 theory in tadpole approximation

abstract:
  Relying on the Luttinger-Ward theorem we derive a thermodynamically
selfconsistent and scale independent approximation of the thermodynamic
potential for the scalar $\phi^4$ theory in the tadpole approximation. The
resulting thermodynamic potential as a function of the temperature is similar
to the one of the recently proposed screened perturbation theory.


title: Proton spin content and QCD topological susceptibility

abstract:
  The part of the proton spin $\Sigma$ carried by $u, d, s$ quarks is
calculated in the framework of the QCD sum rules in the external fields. The
operators up to dimension 9 are accounted. An important contribution comes from
the operator of dimension 3, which in the limit of massless $u, d, s$ quarks is
equal to the derivative of QCD topological susceptibility $\chi^{\prime} (0)$.
The comparison with the experimental data on $\Sigma$ gives $\chi^{\prime}(0)=
(2.3 \pm 0.6) \times 10^{-3} ~ GeV^2$. The limits on $\Sigma$ and
$\chi^{\prime}(0)$ are found from selfconsistency of the sum rule, $\Sigma \ga
0.05,~~ \chi^{\prime} (0) \ga 1.6 \times 10^{-3} ~ GeV^2$. The values of $g_A =
1.37 \pm 0.10$ and $g^8_A = 0.65 \pm 0.15$ are also determined.


title:
Complete Description of Polarization Effects in Top Quark Decays
  Including Higher Order QCD Corrections

abstract:
  The complete set of matrix elements for all polarization configurations in
top quark decays is presented including higher order QCD corrections. The
analysis is done in the framework of the helicity formalism. The results can be
used in a variety of circumstances, e.g. in the experimental analysis of top
quark production and decay at Tevatron, LHC and NLC. Relations to LEP1 and LEP2
physics are pointed out.


title: Strange Multiskyrmions

abstract:
  Using the recently proposed approximation for multiskyrmion fields based on
rational maps we study the masses and baryonic radii of some strange
multibaryons within the bound state soliton model. We find the tetralambda
binding to be stronger than previously expected. In addition, the model
predicts the existence of a ``heptalambda'' which is stable against strong
decays.


title: A Note On R-Parity Violation and Fermion Masses

abstract:
  We consider a class of supersymmetric SU(3)\times SU(2)\times U(1) multihiggs
models in which R-parity is violated through bilinear Higgs-lepton
interactions. The required, due to R-parity violation, higgs-lepton rotations
introduce an alternative way to generate the phenomenologically desirable
fermion mass matrix structures independently of the equality of Yukawas,
possibly imposed by superstring or other unification.


title:
$\pi \Lambda$ scattering phase shifts and CP violation in $\Xi \to \pi
  \Lambda$ decay

abstract:
  CP-violating signals in weak $ \Xi\to \pi \Lambda$ decay require the
knowledge of $\pi \Lambda$ $S$- and $P$-wave scattering phases at ${m}_{\Xi}$
center-of-mass energy. We have calculated these phases in baryon chiral
perturbation theory with the ground-state $\Sigma$ in $s$ and $u$ channels and
${{3 \over 2}}^{+}$ $\Sigma(1385)$ in the $u$ channel. We do not treat the
baryons as heavy. We find ${\delta}_{S} = {1.2}^{\circ}$ and ${\delta}_{P} =
-{1.7}^{\circ}$ with the central value of the strong coupling parameter $D$. We
also investigate the variation of the scattering phases as functions of the
parameter $D$. We compare this result with previous calculations, and discuss
its relevance to CP-asymmetry parameters.


title: Resummed $C$-Parameter Distribution in $e^+e^-$ Annihilation

abstract:
  We give perturbative predictions for the distribution of the $C$-Parameter
event shape variable in $e^+e^-$ annihilation, including resummation of large
logarithms in the two-jet (small-$C$) region, matched to next-to-leading order
results. We also estimate the leading non-perturbative power correction and
make a preliminary comparison with experimental data.


title:
Electroweak Baryogenesis and Neutron Electric Dipole Moment from
  Supersymmetry

abstract:
  Baryogenesis at the electroweak phase transition is discussed within the
framework of the supersymmetric standard model. Implications of baryon
asymmetry for the electric dipole moment of the neutron are also studied.


title: On the odderon intercept in the variational approach

abstract:
  The odderon intercept $ \alpha $ is recalculated by the variational method
based on conformal invariance. The final result is $\alpha=1-0.339 \alpha_s
N/\pi$ in contrast to the published value above unity.


title: About the fine-tuning price of LEP

abstract:
  Following Chankowski, Ellis and Pokorski we quantify the amount of
fine-tuning of input parameters of the Minimal Supersymmetric Standard Model
that is needed to respect the lower limits on sparticle and Higgs masses
imposed by negative searches so far, direct or indirect. By including the one
loop radiative corrections to the effective potential, the amount of
fine-tuning is reduced with respect to the results of CEP by a factor of 2--5,
strongly increasing as tan\beta approaches 1. A further reduction factor may
come from a more appropriate, less restrictive, definition of the fine-tuning
parameter itself.


title: Suppression of Pi NN* Coupling and Chiral Symmetry

abstract:
  Meson-baryon couplings between positive and negative parity nucleons are
investigated using two point correlation functions in the soft meson and the
chiral limit. We find that the pi NN* coupling vanishes due to chiral symmetry,
while the eta NN* coupling remains finite. We perform an analysis based on the
algebraic method for SU(2) chiral symmetry, and find that nucleon axial charges
play an essential role for vanishing coupling constants. For an illustration,
we construct sigma models with N and N*, where we discuss their properties from
the view point of the chiral symmetry. We also discuss N and N* in the
viewpoint of chiral partner.


title:
Indications for an Anomalous Right-Handed Coupling of the b-Quark from a
  Model Independent Analysis of LEP and SLD Data on Z-Decays

abstract:
  A model independent analysis is made using the LEP and SLD data on Z decays
available at the end of 1996. The effective weak coupling constants of leptons,
c quarks and b quarks are extracted. Except for the right-handed b quark
coupling, they all agree well with the predictions of the Standard Electroweak
Model for $m_t = 172$ GeV and $m_H = 263$ GeV. The right-handed b quark
coupling is found to be 42% and 3.2 standard deviations above the Standard
Model prediction.


title:
Coulomb resummation for $b \bar b$ system near threshold and precision
  determination of $\al_s$ and $m_b$.

abstract:
  We analyze sum rules for the $\Upsilon$ system with resummation of threshold
effects on the basis of the nonrelativistic Coulomb approximation. We find for
the pole mass of the bottom quark $m_b=4.75\pm 0.04 GeV$ and for the strong
coupling constant $\al_s(M_Z)=0.118\pm 0.006$. The origin of the contradiction
between two recent estimates obtained within the same formal framework is
clarified.


title:
Effects of multi-pion correlations on the source distribution in
  ultra-relativustic heavy-ion collisions

abstract:
  Multi-pion correlation effect on the source distribution is studied. It is
shown that multi-pion Bose-Einstein correlation make the average radius of the
pion source become smaller. The isospin effect on the pion multiplicity
distribution and the source distribution is also discussed.


title:
The Skyrme Model piNN Form Factor and the Sea Quark Distribution of the
  Nucleon

abstract:
  We calculate the sea quark distribution of the nucleon in a meson cloud
model. The novel feature of our calculation is the implementation of a special
piNN form factor recently obtained by Holzwarth and Machleidt. This form factor
is hard for small and soft for large momentum transfers. We show that this
feature leads to a substantial improvement.


title: Higgs Search in the WW* Decay Mode at Photon Linear Colliders

abstract:
  We present the results of calculations for the process gamma gamma -> W + 2
fermions at a future Photon Linear Collider (PLC). The calculations include at
the same time the next-to-leading order Higgs signal and the complete tree
level gauge boson background. We present numerical results in the intermediate
mass Higgs region 140 GeV < M_H < 2M_W. We propose strategies for the
determination of Higgs properties using the leptonic and hadronic final states
for both polarized and unpolarized photon beams.


title:
Neutrinos in Random Magnetic Fields: The Problem of Measuring Magnetic
  Moments

abstract:
  The existence of magnetic moments of neutrinos points to physics beyond the
standard model. Given current upper limits, terrestrial measurements are
difficult or completely unfeasible. However, estimates of transition moments
can be obtained from observation of objects such as active galactic nuclei
(AGN) by means of neutrino telescopes. We describe the way of estimating the
magnitudes of transition moments from such observations.


title:
Improved Determination of $\alpha(M_{\rm Z}^2$) and the Anomalous
  Magnetic Moment of the Muon

abstract:
  We reevaluate the hadronic contribution to the running of the QED fine
structure constant \aqed at $s=M_{\rm Z}^2$. We use data from \ee\ annihilation
and $\tau$ decays at low energy and at the $q\bar{q}$ thresholds, where
resonances occur. Using so-called spectral moments and the Operator Product
Expansion (OPE), it is shown that a reliable theoretical prediction of the
hadronic production rate $R(s)$ is available at relatively low energies. Its
application improves significantly the precision on the hadronic vacuum
polarization contribution. We obtain \daqedhZ $=(277.8\pm2.6)\times10^{-4}$
yielding $\alpha^{-1}(M_{\rm Z}^2)=128.923\pm0.036$. Inserting this value in a
global electroweak fit using current experimental input, we constrain the mass
of the Standard Model Higgs boson to be $M_{\rm Higgs}=129^{+103}_{-62}~{\rm
GeV}$. Analogously, we improve the precision of the hadronic contribution to
the anomalous magnetic moment of the muon for which we obtain $a_\mu^{\rm
had}=(695.1\pm7.5)\times 10^{-10}$.


title: Observation of UHE Neutrinos from Outer Space

abstract:
  The interaction of UHE neutrinos can be observed from outer space. The
advantage of the proposed method is that the Earth can be used as an energy
filter as well as a target. We sketch the potentials of these observations in
searching for particle physics beyond the Standard Model of elementary particle
interactions as well as observations of astronomical objects such as active
galactic nuclei.


title:
B0(t) -> DPP time-dependent Dalitz plots, CP-violating angles 2beta,
  2beta+gamma, and discrete ambiguities

abstract:
  We study CP-violation in resonant three-body B -> DPP decays, where PP stands
for either Dpi, DK_S, pipi or piK_S. Analogously to the B -> 3pi channel and
the extraction of 2alpha, the first three channels are shown to measure
cos(2beta) in addition to sin(2beta), thus allowing to resolve the beta -> pi/2
-beta ambiguity, while the DpiK_S final state leads to a measurement of
2beta+gamma. The B0(t) -> D+D-pi0 channel via the interference between D**
orbitally excited resonances is taken as an example, although this
Cabibbo-suppressed decay suffers from irreducible penguin uncertainties. Then
two penguin-free and Cabibbo-dominant modes are proposed: B0(t) -> D+D-K_S with
the D_s** resonances, and B0(t) -> D0_CP pi+pi- with the D** plus the rho.
Finally, the B0(t) -> D+-pi-+K_S channel with the D_s** and K* resonances
provides a new clean method to measure the unusual angle 2beta+gamma. We
present in all cases a crude estimate of the number of cos(2beta) (respectively
2beta+gamma) sensitive events. We show that this number is an increasing
function of the resonance mass, a favorable situation compared to the more
extensively studied three-pion Dalitz plot. However, the poor detection
efficiency of the D mesons could pose a problem. As an annex and speculative
application of these Dalitz plot based methods, the penguin-dominated B0(t) ->
K_SK_SK_L decay also measures 2beta.


title:
On the Thermal Gauge Boson Masses of the Electroweak Theory in the
  Broken Phase

abstract:
  Thermal effects in the broken phase of the electroweak theory are studied in
the strongly interacting Higgs boson limit. In that limit and at tree level the
bosonic sector of the theory is a gauged non-linear sigma model. The associated
one-loop thermal effective action for soft fields is then computed by using the
background field method together with the Stueckelberg formalism. This
effective action describes thermal corrections to the masses of the gauge
bosons W, Z and the photon. It is the proper generalization of the hard thermal
effective action of a Yang-Mills theory when there is a Higgs mechanism for a
heavy Higgs particle.


title: The Higgs mass in the MSSM infrared fixed point scenario

abstract:
  In the infrared fixed point (IFP) scenario of the minimal supersymmetric
model (MSSM), the top-quark mass and other physical quantities of the
low-energy theory are insensitive to the values of the parameters of the theory
at some high energy scale. In this framework we evaluate the light CP-even
Higgs mass, $m_h$, taking into account some important effects that had not been
previously considered. In particular, the supersymmetric correction to the
relation between the running and the physical top-quark masses lowers the value
of $\tan\beta$, thereby implying a lower predicted value of $m_h$. Assuming a
supersymmetric threshold of $M_S\leq 1$ TeV and $M_t=175$ GeV, we find an upper
bound of $m_h\le 97\pm 2$ GeV; the most plausible value of $m_h$ lies somewhat
below the upper bound. This places the Higgs boson in the IFP scenario well
within the reach of the LEP-2 Higgs search.


title: Low Energy Experiments on pi-pi Scattering

abstract:
  General interest in a precise determination of the threshold pi-pi amplitudes
has recently increased markedly due to a controversy regarding the size of
<0|qbar q|0>, the scalar quark condensate. This paper examines the current
experimental information on the pi-pi scattering lengths, in particular the
recent low energy pi N -> pi pi N data from several laboratories and the
related application of the Chew-Low-Goebel technique well below 1 GeV/c
momentum. It appears that uncertainties related to the treatment of
non-pion-exchange backgrounds in these studies do not yet allow an unambiguous
resolution of the <0|qbar q|0> size. However, near-term prospects for new
model-independent results of improved precision are very good.


title: Topological Defects: Fossils from the Early Universe

abstract:
  In the context of current particle physics theories, it is quite likely that
topological defects may be present in our universe. An observation of these
fossils from the early universe would lead to invaluable insight into cosmology
and particle physics, while their absence provides important constraints on
particle-cosmology model building. I describe recent efforts to address
cosmological issues in condensed matter systems such as He-3 and a possible
solution to the magnetic monopole problem due to defect interactions. (Invited
talk at the 1997 RESCEU Symposium, University of Tokyo.)


title: Update on Atmospheric Neutrinos

abstract:
  We discuss the impact of recent experimental results on the determination of
atmospheric neutrino oscillation parameters. We use all published results on
atmospheric neutrinos, including the preliminary large statistics data of
Super-Kamiokande. We re-analyze the data in terms of both $\nu_\mu \to
\nu_\tau$ and $\nu_\mu \to \nu_e$ channels using new improved calculations of
the atmospheric neutrino flux. We compare the sensitivity attained in
atmospheric neutrino experiments with those of accelerator and reactor neutrino
oscillation searches, including the recent Chooz experiment. We briefly comment
on the implications of atmospheric neutrino data in relation to future searches
for neutrino oscillations with long baselines, such as the K2K, MINOS, ICARUS
and NOE experiments.


title: Helicity-Flip Off-Foward Parton Distributions of the Nucleon

abstract:
  We identify quark and gluon helicity-flip distributions defined between
nucleon states of unequal momenta. The evolution of these distributions with
change of renormalization scale is calculated in the leading-logarithmic
approximation. The helicity-flip gluon distributions do not mix with any quark
distribution and are thus a unique signature of gluons in the nucleon. Their
contribution to the generalized virtual Compton process is obtained both in the
form of a factorization theorem and an operator product expansion. In deeply
virtual Compton scattering, they can be probed through distinct angular
dependence of the cross section.


title: Top Pair Production in e^+ e^- and gamma gamma Processes

abstract:
  We analyze spin correlations between top quark and anti-top quark produced at
polarized e^+ e^- and gamma gamma colliders. We consider a generic spin basis
to find a strong spin correlation. Optimal spin decompositions for top quark
pair are presented for e^+ e^- and gamma gamma colliders. We show the
cross-section in these bases and discuss the characteristics of results.


title:
The effect of spin oscillation of relativistic particles passing through
  substance and the possibility of the constituent quark rescattering
  observation at omega-hyperon - proton collision

abstract:
  For the omega-hyperon passing through matter the phenomena of spin rotation
and oscillation has investigated quantitatively. Connection of these phenomena
with constituent quark rescattering has been determined. It allows one to
investigate quark rescattering directly without background of a single
scattering.


title: QCD, Theoretical issues

abstract: Today's QCD problems, prospects and achievements are reviewed.


title: Radiatively Corrected Chargino Pair Production at LEP2

abstract:
  One-loop radiative corrections to the production cross section of a pair of
light charginos in e+e- colliders are calculated within the MSSM. Top and
bottom quarks and squarks are considered in the loops, and they are
renormalized using the MS-bar scheme. If the center of mass energy is equal to
192 GeV, positive corrections typically of 10% to 15% are found when the squark
mass parameters are equal to 1 TeV.


title: R-Parity Violation and Photon-Neutrino Interactions

abstract:
  In the framework of the supersymmetric theories with R-parity violation we
consider the process $\gamma \gamma \to \nu_i \bar{\nu_j}$ and its contribution
into energy loss from the stars.Under some conditions the studied contribution
exceeds the standard model contribution to the same process.


title: NLL resummation of the heavy-quark hadroproduction cross-section

abstract:
  We compute the effect of soft-gluon resummation, at the
next-to-leading-logarithmic level, in the hadroproduction cross-section for
heavy flavours. Applications to top, bottom and charm total cross-sections are
discussed. We find in general that the corrections to the fixed
next-to-leading-order results are larger for larger renormalization scales, and
small, or even negative, for smaller scales. This leads to a significant
reduction of the scale-dependence of the results, for most experimental
configurations of interest.


title: On the Soft Supersymmetry Breaking Parameters in Gauge-Mediated Models

abstract:
  Gauge mediation of supersymmetry breaking in the observable sector is an
attractive idea, which naturally alleviates the flavour changing neutral
current problem of supersymmetric theories. Quite generally, however, the
number and quantum number of the messengers are not known; nor is their
characteristic mass scale determined by the theory. Using the recently proposed
method to extract supersymmetry-breaking parameters from wave-function
renormalization, we derived general formulae for the soft
supersymmetry-breaking parameters in the observable sector, valid in the small
and moderate $\tan\beta$ regimes, for the case of split messengers. The full
leading-order effects of top Yukawa and gauge couplings on the soft
supersymmetry-breaking parameters are included. We give a simple interpretation
of the general formulae in terms of the renormalization group evolution of the
soft supersymmetry-breaking parameters. As a by-product of this analysis, the
one-loop renormalization group evolution of the soft supersymmetry breaking
parameters is obtained for arbitrary boundary conditions of the scalar and
gaugino mass parameters at high energies.


title: WKB quantization of reggeon compound states in high-energy QCD

abstract:
  We study the spectrum of the reggeized gluon compound states in high-energy
QCD. The energy of the states depends on the total set of quantum numbers whose
values are constrained by the quantization conditions. To establish their
explicit form we apply the methods of nonlinear WKB analysis to the
Schr\"odinger equation for the $N$ reggeon state in the separated coordinates.
We solve the quantization conditions for the N=3 reggeon states in the leading
order of the WKB expansion and observe a good agreement of the obtained
spectrum of quantum numbers with available exact solutions.


title:
Topics on the Physics Potential and Detector Aspects of the LC-HERA ep
  Collider

abstract:
  We give a brief account of some physics topics which could be addressed at a
collider consisting of the HERA proton ring and the future e+e- Linear
Collider. A few experimental aspects are also discussed.


title: Chiral Odd Structure Functions from a Chiral Soliton

abstract:
  We calculate the chiral odd quark distributions and the corresponding
structure functions $h_T(x,Q^2)$ and $h_L(x,Q^2)$ within the Nambu-Jona-Lasinio
chiral soliton model for the nucleon. The $Q^2$ evolution of the twist-2
contributions is performed according to the standard GLAP formalism while the
twist-three piece, $\bar{h}_L(x)$, is evolved according to the large $N_C$
scheme. We carry out a comparison between the chiral odd structure functions of
the proton and the neutron. At the low model scale ($Q_0^2$) we find that the
leading twist effective quark distributions,$f_1^{(q)}(x,Q_0^2)$,
$g_1^{(q)}(x,Q_0^2)$ and $h_T^{(q)}(x,Q_0^2)$ satisfy Soffer's inequality for
both quark flavors $q=u,d$.