title: Effective operators in Supersymmetry

abstract:
  We consider a low-energy supersymmetric scenario in which the effects of
heavy supersymmetric interactions are included in a model-independent manner
through a series of supersymmetric SU(3)_C*SU(2)_L*U(1)_Y invariant operators;
we explicitly construct all such operators of dimension less or equal than 6.
From this set, those operators generated at tree level by the underlying theory
are isolated since under weak coupling conditions they are expected to provide
the largest effects in low-energy processes. Potential deviations from low
energy predictions in process such as proton decay, neutrinoless double-beta
decay and flavor changing neutral currents are analyzed as illustrations of the
method.


title: Single Polarisation Asymmetries for Quarkonia in Non-relativistic QCD

abstract:
  We find that single spin asymmetries in NRQCD are non-vanishing in general.
They are proportional to the imaginary parts of some non-perturbative matrix
elements. With statistics of about 10^6 identified J/psi's, or 10^5 identified
chi_2, it is possible to measure these imaginary parts even if they are an
order of magnitude smaller than the real parts. Such statistics are quite
reasonable at polarised HERA N and other future experiments.


title: Charmless B decays to eta' and eta

abstract:
  Exclusive charmless B decays to $\eta'$ and $\eta$ are studied in the
standard effective Hamiltonian approach. The effective coefficients that take
into account nonfactorizable effects in external and internal W-emission
amplitudes are fixed by experiment. Factorization is applied to the matrix
elements of QCD, electroweak penguin operators and next-to-leading corrections
to penguin Wilson coefficients, which are renormalization-scheme dependent, are
included, but the resultant amplitude is renormalization-scheme and -scale
independent. We show that the unexpectedly large branching ratio of $B^\pm\to
\eta' K^\pm$ measured by CLEO can be explained by the Cabibbo-allowed internal
W-emission process $b\to c\bar cs$ followed by a conversion of the $c\bar c$
pair into the $\eta'$ via gluon exchanges characterized by a decay constant of
order -50 MeV. Implications are discussed. The mechanism of the transition
$c\bar c\to\eta'$, if correct, will enhance the decay rates of $B\to \eta'
K^{*}$ by more than an order of magnitude. However, it plays only a minor role
to the rare decays $B\to \eta'(\eta)\pi(\rho)$. The predicted branching ratio
of $B^\pm\to \eta\pi^\pm$ for positive $\rho$ is marginally ruled out by
experiment, indicating that the favored Wolfenstein parameter $\rho$ is
negative.


title: Challenges for Inverted Hybrid Inflation

abstract:
  Inverted hybrid inflation (in which the inflaton field slowly rolls away from
the origin, giving a spectral index $n\lsim 1$) is an appealing variant of the
more usually studied hybrid model. Analysing the model alongside the ordinary
hybrid case, we show that, in order to provide the correct density
perturbations consistent with the COBE measurements, the dimensionless coupling
constants of the inverted hybrid potential must be very small indeed. For
example, the quartic coupling in a typical such potential is found to be $\lsim
10^{-12}$. A supersymmetric model of inverted hybrid inflation, which does not
involve the troublesome quartic coupling is found to lead to a potential which
is unbounded from below.


title: Higher-order estimates of the chromomagnetic moment of a heavy quark

abstract:
  The leading beta_0^(n-1) alpha_s^n terms in the Wilson coefficient and
anomalous dimension of the chromomagnetic operator in the heavy-quark effective
Lagrangian are summed to all orders of perturbation theory. The perturbation
series for the anomalous dimension is well behaved, while that for the Wilson
coefficient exhibits a divergent behaviour already in low orders, caused by a
nearby infrared renormalon singularity. The resulting ambiguity is commensurate
with terms of order 1/m^2 in the effective Lagrangian, whose corresponding
ultraviolet renormalons are identified. An excellent approximation for the
scheme-invariant Wilson coefficient at next-to-next-to-leading order in
renormalization-group improved perturbation theory is obtained.


title:
Inclusive Single- and Dijet Rates in Next-to-Leading Order QCD for
  gamma^*proton and gamma^*gamma Collisions

abstract:
  We present one- and two-jet inclusive cross sections for gamma*gamma
scattering and virtual photoproduction in ep collisions. The hard cross
sections are calculated in next-to-leading order QCD. Soft and collinear
singularities are extracted using the phase-space-slicing method. The initial
state singularity of the virtual photon depends logarithmically its'
virtuality. This logarithm is large and has to be absorbed into the parton
distribution function of the virtual photon. We define for this purpose an
MS-bar factorization scheme similar to the real photon case. We numerically
study the dependence of the inclusive cross sections on the transverse energies
and rapidities of the outgoing jets and on the photon virtuality. The ratio of
the resolved to the direct cross section in ep collisions is compared to ZEUS
data.


title: On the low x behaviour of nuclear shadowing

abstract:
  We calculate the x dependence of nuclear shadowing at moderate values of Q^2
by using HERA diffractive data and, for consistency, F2 parameterization of
ZEUS. We show that no decrease of shadowing occurs down to very low x (x =
10^-4).


title: Theory of Top Quark Production and Decay

abstract:
  Direct and indirect information on the top quark mass and its decay modes is
reviewed. The theory of top production in hadron- and
electron-positron-colliders is presented.


title: H-function extension of the NBD in the light of experimental data

abstract:
  The recently introduced H-function extension of the Negative Binomial
Distribution is investigated. The analytic form of P(n) is rederived by means
of the Mellin transform. Applications of the HNBD are provided using
experimental data for P(n) in e+e-, e+p, inelastic pp and non-diffractive
p-pbar reactions.


title: Better Jet Clustering Algorithms

abstract:
  We investigate modifications to the $k_\perp$-clustering jet algorithm which
preserve the advantages of the original Durham algorithm while reducing
non-perturbative corrections and providing better resolution of jet
substructure. We find that a simple change in the sequence of clustering
(combining smaller-angle pairs first), together with the `freezing' of soft
resolved jets, has beneficial effects.


title: Effective action and motion of a cosmic string

abstract:
  We examine the leading order corrections to the Nambu effective action for
the motion of a cosmic string, which appear at fourth order in the ratio of the
width to radius of curvature of the string. We determine the numerical
coefficients of these extrinsic curvature corrections, and derive the equations
of motion of the worldsheet. Using these equations, we calculate the
corrections to the motion of a collapsing loop, a travelling wave, and a
helical breather. From the numerical coefficients we have calculated, we
discuss whether the string motion can be labelled as `rigid' or `antirigid,'
and hence whether cusp or kink formation might be suppressed or enhanced.


title: Quark Propagator and Meson Correlators in the QCD Vacuum

abstract:
  Equal time, point to point correlation functions for spatially separated
meson currents are calculated with respect to a variational construct for the
ground state of QCD. Given such an ansatz we make no further approximations in
the evaluation of the correlators. Our calculations for the vector, axial
vector and scalar channels show qualitative agreement with the phenomenological
predictions, whereas the pseudoscalar channel does not. However, the
pseudoscalar correlator, when approximated by saturating with intermediate one
pion states agrees with results obtained from spectral density functions
parameterised by pion decay constant and $<-\bar \psi \psi>$ value obtained
from chiral perturbation theory. We discuss this departure in the pseudoscalar
channel, in context of the quark propagation in the vacuum.


title:
Non-factorizable corrections to W-pair production: methods and analytic
  results

abstract:
  In this paper we present two methods to evaluate non-factorizable corrections
to pair-production of unstable particles. The methods are illustrated in detail
for W-pair-mediated four-fermion production. The results are valid a few widths
above threshold, but not at threshold. One method uses the decomposition of
$n$-point scalar functions for virtual and real photons, and can therefore be
generalized to more complicated final states than four fermions. The other
technique is an elaboration on a method known from the literature and serves as
a useful check. Applications to other processes than W-pair production are
briefly mentioned.


title:
A Solution to Coupled Dyson-Schwinger Equations for Gluons and Ghosts in
  Landau Gauge

abstract:
  A truncation scheme for the Dyson-Schwinger equations of QCD in Landau gauge
is presented which implements the Slavnov-Taylor identities for the 3-point
vertex functions. Neglecting contributions from 4-point correlations such as
the 4-gluon vertex function and irreducible scattering kernels, a closed system
of equations for the propagators is obtained. For the pure gauge theory without
quarks this system of equations for the propagators of gluons and ghosts is
solved in an approximation which allows for an analytic discussion of its
solutions in the infrared: The gluon propagator is shown to vanish for small
spacelike momenta whereas the ghost propagator is found to be infrared
enhanced. The running coupling of the non-perturbative subtraction scheme
approaches an infrared stable fixed point at a critical value of the coupling
alpha_c of approx. 9.5. The gluon propagator is shown to have no Lehmann
representation. The results for the propagators obtained here compare favorably
with recent lattice calculations.


title:
Leptoquark production in ultrahigh-energy neutrino interactions
  revisited

abstract:
  The prospects for producing leptoquarks (LQs) in ultrahigh-energy (UHE)
neutrino nucleon collisions are re-examined in the light of recent
interpretations of HERA data in terms of leptoquark production. We update
predictions for cross-sections for the production of first- and
second-generation leptoquarks in UHE nu-N and nubar-N collisions including
  (i) recent experimental limits on masses and couplings from the LEP and
TEVATRON colliders as well as rare processes,
  (ii) modern parton distributions, and
  (iii) radiative corrections to single leptoquark production.
  If the HERA events are due to an SU(2) doublet leptoquark which couples
mainly to (e+,q) states, we argue that there are likely other LQ states which
couple to neutrinos which are close in mass, due to constraints from precision
electroweak measurements.


title: Pion Light-Cone Wave Functions and Light-Front Quark Model

abstract:
  We discuss a relation between the light-front quark model and QCD. We argue
that this model can be used for an evaluation of the light-cone wave functions
for moderate values of "u", but that it is inapplicable for this purpose in the
region near the ends points u=0,1. We find additional support for a recent
analysis in which it was claimed that the twist-two pion wave function attains
its asymptotic form. The asymptotic twist-four two-particle wave function is
also in good agreement with the light-front quark model.


title: Inflation and the Nature of Supersymmetry Breaking

abstract:
  The scale at which supersymmetry is broken and the mechanism by which
supersymmetry breaking is fed down to the observable sector has rich
implications on the way Nature may have chosen to accomplish inflation. We
discuss a simple model for slow rollover inflation which is minimal in the
sense that the inflaton may be identified with the field responsible for the
generation of the $\mu$-term. Inflation takes place at very late times and is
characterized by a very low reheating temperature. This property is crucial to
solve the gravitino problem and may help to ameliorate the cosmological moduli
problem. The COBE normalized value of the vacuum energy driving inflation is
naturally of the order of $10^{11}$ GeV. This favors the N=1 supergravity
scenario where supersymmetry breaking is mediated by gravitational
interactions. Nonetheless, smaller values of the vacuum energy are not excluded
by present data on the temperature anisotropy and the inflationary scenario may
be implemented in the context of new recent ideas about gauge mediation where
the standard model gauge interactions can serve as the messangers of
supersymmetry breaking. In this class of models supersymmetry breaking masses
are usually prop ortional to the F-term of a gauge singlet superfield. The same
F-term may provide the vacuum energy density necessary to drive inflation. The
spectrum of density perturbations is characterized by a spectral index which is
significantly displaced from one. The measurements of the temperature
anisotropies in the cosmic microwave background radiation at the accuracy
expected to result from the planned missions will be able to confirm or
disprove this prediction and to help in getting some deeper insight into the
nature of supersymmetry breaking.


title: Light-Gravitino Production at Hadron Colliders

abstract:
  We consider the production of gravitinos ($\widetilde G$) in association with
gluinos ($\tilde g$) or squarks ($\tilde q$) at hadron colliders, including the
three main sub-processes: $q \bar q -> \tilde g\widetilde G$, $qg -> \tilde
q\widetilde G$, and $gg -> \tilde g\widetilde G$. These channels become
enhanced to the point of being observable for sufficiently light gravitino
masses ($m_{\widetilde G} < 10^{-4} eV$), as motivated by some supersymmetric
explanations of the CDF $ee\gamma\gamma+ E_{T,miss}$ event. The characteristic
signal of such events would be monojets, as opposed to dijets obtained in the
more traditional supersymmetric process $p \bar p -> \tilde g\tilde g$.
Searches for such events at the Tevatron can impose lower limits on the
gravitino mass. In the Appendix, we provide a complete set of Feynman rules for
gravitino interactions used in our calculation.


title: Predicative Ability of QCD Sum Rules for Decuplet Baryons

abstract:
  QCD sum rules for decuplet baryon two-point functions are investigated using
a comprehensive Monte-Carlo based procedure. In this procedure, all
uncertainties in the QCD input parameters are incorporated simultaneously,
resulting in realistic estimates of the uncertainties in the extracted
phenomenological parameters. Correlations between the QCD input parameters and
the phenomenological parameters are studied by way of scatter plots. The
predicted couplings are useful in evaluating matrix elements of decuplet
baryons in the QCD sum rule approach. They are also used to check a cubic
scaling law between baryon couplings and masses, as recently found by Dey and
coworkers. The results show a significant reduction in the scaling constant and
some possible deviations from the cubic law.


title: Neutralino Annihilation into a Photon and a Z boson

abstract:
  A full one-loop calculation of neutralino S-wave annihilation into the
$Z\gamma$ final state is performed in the minimal supersymmetric extension of
the Standard Model. This process, like the similar one with two photons in the
final state, may be of importance for the indirect detection of supersymmetric
dark matter through the very narrow $\gamma$ ray line that would result from
neutralino annihilations in the galactic halo.
  We give the complete analytical formulas for this loop-induced process and
treat the case of a pure Higgsino as a first application of our expressions.
Predictions for the gamma line flux are given for the halo model which is of
the form suggested by Kravtsov et al. and for the profile proposed by Navarro,
Frenk and White.
  For heavy neutralinos, the lines from $2\gamma$ and $Z\gamma$ would have
indistiguishable energy in a realistic detector, making the fluxes add and
facilitating discovery. For lighter neutralinos, the positions and relative
strengths of the two lines would give valuable information on the nature of the
supersymmetric dark matter particles.


title:
Constraints on four-Fermi contact interactions from low-energy
  electroweak experiments

abstract:
  We investigate the constraints on four-Fermi contact interactions from
low-energy lepton-quark and lepton-lepton scattering experiments ---
polarization asymmetries in electron (muon)-nucleon scattering experiments,
cesium and thallium atom parity violation measurements, neutrino-nuclei and
neutrino-electron scattering experiments. These constraints are then combined
by assuming the lepton and quark universalities and SU(2)*U(1) gauge invariance
of the contact interaction, which leave independent six lepton-quark and three
pure-leptonic interactions.Impacts of these constraints on models with an
additional Z-boson are briefly discussed. We also present updates of the
low-energy constraints on the S and T parameters.


title: QCD sum rules: form factors and wave functions

abstract:
  The shape of hadronic distribution amplitudes (DAs) is a critical issue for
the perturbative QCD of hard exclusive processes. Recent CLEO data on gamma
gamma* -> pi^0 form factor clearly favor a pion DA close to the asymptotic
form. We argue that QCD sum rules for the moments of the pion DA \varphi_\pi(x)
are unreliable, so that the humpy shape of \varphi_\pi (x) obtained by Chernyak
and Zhitnitsky is a result of model assumptions rather than an unambigous
consequence of QCD sum rules. This conclusion is also supported by a direct QCD
sum rule calculation of the gamma gamma* -> pi^0 form factor which gives a
result very close to the CLEO data.


title:
Effect of SUSY phases on the $B^0_d - \bar{B}^0_d$ mixing in the minimal
  supergravity model

abstract:
  We investigate the effect of SUSY phases ($\theta_A$ and $\theta_\mu$) on the
$B^0_d - \bar{B}^0_d$ mixing in the minimal supergravity model. It is known
that the complex phase $\theta_A$ $=$ arg($A$) ($A$ is the universal
coefficient of the trilinear scalar couplings) is essentially unconstrained by
the electric dipole moment experiment, while the phase $\theta_\mu$ $=$
arg($\mu$) ($\mu$ is the supersymmetric Higgsino mass) is strongly constrained
to zero. We found that $\theta_A$ does not affect the phase of the $B^0_d -
\bar{B}^0_d$ mixing matrix element $M_{12}(B)$ by numerical analysis of the
renormalization group equations. This means that the measurement of the $B^0_d
- \bar{B}^0_d$ mixing at the future B-factory could give the direct information
on the parameters of the CKM matrix even in the framework of the minimal
supergravity model with the SUSY phase $\theta_A$.


title:
The Single Photon Annihilation Contributions to the Positronium
  Hyperfine Splitting to Order $m_e\alpha^6$

abstract:
  The single photon annihilation contributions for the positronium ground state
hyperfine splitting are calculated analytically to order $m_e\alpha^6$ using
NRQED. Based on intuitive physical arguments the same result can also be
determined by a trivial calculation using results from existing literature. Our
result completes the hyperfine splitting calculation to order $m_e\alpha^6$. We
compare the theoretical prediction with the most recent experimental
measurement.


title:
Jet Shapes in Hadron Collisions: Higher Orders, Resummation and
  Hadronization

abstract:
  The jet shape is a simple measure of how widely a jet's energy is spread. At
present jet shape distributions have only been calculated to leading order in
perturbative QCD. In this paper we consider how much these predictions should
be affected by higher order perturbative corrections, by resummation of
enhanced corrections to all orders, and by (power-suppressed) non-perturbative
corrections. We also show that current cone-type jet definitions are not
infrared safe for final states with more than three partons. Unless this
situation is rectified by using improved definitions, hadron collider
experiments will never be able to study the internal properties of jets with
the quantitative accuracy already achieved in $e^+e^-$ annihilation.


title: Spin structure functions in leptoproduction

abstract:
  We discuss a few examples of structure functions for polarized,
semi-inclusive scattering processes to show the richness of structure. Then we
indicate how polarization and particle production can be used to study the
quark and gluon structure of hadrons going further than the well-known parton
densities and fragmentation functions.


title: Distribution and fragmentation functions in a spectator model

abstract:
  Quark distribution and spectator functions are estimated in a diquark
spectator model. The representation of the functions in terms of non-local
operators together with the rather simple model allow estimates for the yet
experimentally undetermined functions, like the polarized fragmentation
functions or higher twist functions.


title: Chiral sum rules to second order in quark mass

abstract:
  A new calculation of the isospin and hypercharge axialvector current
propagators ($\Delta_{A33}^{\mu\nu}(q^2)$ and $\Delta_{A88}^{\mu\nu}(q^2)$) to
two loops in SU(3) x SU(3) chiral perturbation theory is used to derive chiral
spectral function sum rules valid to second order in the light quark masses.
Explicit forms are given for the three-pion isospin axialvector spectral
functions at low energy and application of the sum rules to the determination
of counterterms of the chiral lagrangian is discussed.


title:
Classical approximation for time dependent quantum field theory:
  diagrammatic analysis for hot scalar fields

abstract:
  We study time dependent correlation functions in hot quantum and classical
field theory for the $\lambda\phi^4$ case. We set up the classical analogue of
thermal field theory and make a direct comparison between the quantum and
classical diagrams. A restriction to time independent correlation functions
gives the connection with conventional dimensional reduction. If the parameters
in the classical theory are chosen according to the dimensional reduction
matching relations, the classical expressions are cutoff independent and they
approximate the quantum expressions, provided that the external momenta and
frequencies are small with respect to the temperature.


title: The $\beta$-spectrum in presence of background potentials for neutrinos

abstract:
  We compute the spectrum of $\beta$-decay, assuming that (Majorana or Dirac)
neutrinos propagate in constant potentials. We study the modifications of the
spectrum due to the effect of these potentials. Data on tritium decay and on
${}^3$H--${}^3$He mass difference allow us to infer bounds in the electronvolts
range on the potentials.


title: Nuclear Effects in Charmonium Production in QCD

abstract:
  It is shown that the nuclear shadowing of charmonium due to the modification
of the nuclear parton distribution is similar in the factorization approach
based on non relativistic QCD and in the color evaporation model. In the first
model, a separate study of the color octet and color singlet contributions to
the yields of the various charmonium states as well as the contributions of
these states to the total $J/\Psi$ production is performed. It is found a clear
$x_F$ dependence of these contributions which can reproduce experimental data
for moderate $x_F$.


title: Jet photoproduction at HERA

abstract:
  We compute various kinematical distributions for one-jet and two-jet
inclusive photoproduction at HERA. Our results are accurate to next-to-leading
order in QCD. We use the subtraction method for the cancellation of infrared
singularities. We perform a thorough study of the reliability of QCD
predictions; in particular, we consider the scale dependence of our results and
discuss the cases when the perturbative expansion might break down. We also
deal with the problem of the experimental definition of the pointlike and
hadronic components of the incident photon, and briefly discuss the sensitivity
of QCD predictions upon the input parameters of the calculation, like
$\alpha_S$ and the parton densities.


title: Evidence for eikonal zeros in the momentum transfer space

abstract:
  We present the results of fitting elastic $pp$ differential cross section
data at 23.5 $\leq \sqrt{s} \leq$ 62.5 GeV with a novel analytic
parametrization for the scattering amplitude. Making use of a fitting method,
the errors from the free parameters are propagated to the imaginary part of the
eikonal in the momentum transfer space. A novel systematic study of the effects
coming from data at large momentum transfer is also performed. We find
statistical evidence for the existence of eikonal zeros in the interval of
momentum transfer 5-9 $GeV^{2}$.


title: Effective Field Theory Description of the Pion Form Factor

abstract:
  Using our present knowledge on effective hadronic theories, short-distance
QCD information, the $1/N_C$ expansion, analyticity and unitarity, we derive an
expression for the pion form factor, in terms of $m_\pi, m_K, M_\rho$ and
$f_\pi$. This parameter-free prediction provides a surprisingly good
description of the experimental data up to energies of the order of 1 GeV.


title: BFKL in forward jet production

abstract:
  In this talk I consider dijet production at large rapidity intervals in
hadron collisions and forward-jet production in DIS as candidate signatures of
a BFKL evolution. The state of the art on the measurements, and on the
BFKL-motivated phenomenological analyses with emphasis on the different
approximations involved, is reviewed.


title: Jet Phenomenology

abstract:
  We discuss the phenomenology of jet physics at hadron colliders,
concentrating on the internal structure of jets, which is studied using the jet
shape distribution or subjet distributions.


title:
An estimation of the Higgs boson mass in the two loop approximation in a
  noncommutative differential geometry

abstract:
  In the two loop approximation, a renormalization group analysis of the Higgs
boson mass is performed based on the condition $g^2=(5/3)g'^2=4\lambda$ for
SU(2)_L, U(1)_Y gauge and the Higgs quartic coupling constants, respectively.
This condition is introduced in the new scheme of our noncommutative
differential geometry (NCG) for the reconstruction of the standard model.
However, contrary to SU(5) GUT without supersymmetry, the grand unification of
coupling constants is not realized in this scheme. The physical mass of the
Higgs boson depends strongly on the top quark mass $m_{top}$ through the Yukawa
coupling of the top quark in the $\beta$ functions.The two loop effect lowers
the numerical value calculated within the one loop approximation by several
GeV. The Higgs boson mass varies from 150.25GeV to 167.15GeV corresponding to
169.34GeV< m_{top}<181.02GeV. We find the Higgs boson mass m_H=158.18GeV for
m_{top}=175.04GeV and $m_H=166.12GeV for m_{top}=180.34GeV.


title:
Effective non-perturbative real-time dynamics of soft modes in hot gauge
  theories

abstract:
  We derive, from first principle, the Fokker-Planck equation describing the
non-perturbative real-time evolution of a gauge field at high temperatures on
the spatial scale $(g^2T)^{-1}$ and the time scale $(g^4T)^{-1}$, where $g$ is
the gauge coupling and $T$ is the temperature. The knowledge of the effective
dynamics on such spatial and time scales is crucial for the understanding and
quantitative calculation of the baryon number violation rate at high
temperatures in the electroweak theory. The Fokker-Planck equation, which
describes the diffusive motion of soft components of the gauge field in the
space of field configurations, is shown to be gauge-invariant and consistent
with the known thermodynamics of soft gauge modes. We discuss the ways the
Fokker-Planck equation can be made useful for numerical simulations of
long-distance dynamics of hot gauge theories.


title:
Nucleon Structure Functions from a Chiral Soliton in the Infinite
  Momentum Frame

abstract:
  We study the frame dependence of nucleon structure functions obtained within
a chiral soliton model for the nucleon. Employing light cone coordinates and
introducing collective coordinates together with their conjugate momenta,
translational invariance of the solitonic quark fields (which describe the
nucleon as a localized object) is restored. This formulation allows us to
perform a Lorentz boost to the infinite momentum frame of the nucleon. The
major result is that the Lorentz contraction associated with this boost causes
the leading twist contribution to the structure functions to properly vanish
when the Bjorken variable $x$ exceeds unity. Furthermore we demonstrate that
for structure functions calculated in the valence quark approximation to the
Nambu--Jona--Lasinio chiral soliton model the Lorentz contraction also has
significant effects on the structure functions for moderate values of the
Bjorken variable $x$.


title:
High energy parton-parton amplitudes from lattice QCD and the stochastic
  vacuum model

abstract:
  Making use of the gluon gauge-invariant two-point correlation function,
recently determined by numerical simulation on the lattice in the quenched
approximation and the stochastic vacuum model, we calculate the elementary
(parton-parton) amplitudes in both impact-parameter and momentum transfer
spaces. The results are compared with those obtained from the Kr\"{a}mer and
Dosch ansatz for the correlators. Our main conclusion is that the divergences
in the correlations functions suggested by the lattice calculations do not
affect substantially the elementary amplitudes. Phenomenological and
semiempirical information presently available on elementary amplitudes is also
referred to and is critically discussed in connection with some theoretical
issues.


title: $\eta'$ production in B-decays: Standard Model vs. New Physics

abstract:
  Standard model factorization can account for the large rate for $B^\pm \to
\eta' K^\pm$. The large rate for $B \to \eta' X_s$ is more problematic and
requires a ``cocktail'' solution. Individual contributions from factorization,
$b \to \eta' s g$, and ``intrinsic charm'' fall significantly short of the
observed rate. In contrast, the observed $\eta'$ yields are easily explained in
models with $B(b \to sg) \sim 15%$. Factorization can account for the entire
semi-inclusive $\eta'$ yield without violating rare decay constraints.
Implications for CP violation are discussed.


title:
Possible Excess in Charged Current Events with High-Q^2 at HERA from
  Stop and Sbottom Production

abstract:
  We investigate a production process $e^+p \to \st X \to \sb W^+ X$ at HERA,
where we consider a decay mode $\sb \to \bar{\nu}_e d$ of the sbottom in the
framework of an R-parity breaking supersymmetric standard model. Both processes
of the stop production $e^+ d \to \st$ and the sbottom decay $\sb \to
\bar{\nu}_e d$ are originated from an R-parity breaking superpotential
$\lambda'_{131} \hat{L}_1 \hat{Q}_3 \hat{D^c}_1$. One of signatures of the
process should be a large missing transverse momentum plus multijet events
corresponding to hadronic decays of the $W$. It is shown that the signal could
appear as an event excess in the charged current (CC) processes $e^+p \to \nu
X$ with the high $Q^2$ at HERA. We compare expected event distributions with
the CC data recently reported by the H1 and ZEUS groups at HERA. Methods for
extracting the signal from the standard CC processes are also discussed.


title: How the "H-particle" unravels the quark dynamics

abstract:
  It is shown that the short-range part of the Goldstone boson exchange
interaction between the constituent quarks which explains baryon spectroscopy
and the short-range repulsion in the NN system induces a strong short-range
repulsion in the flavour-singlet state of the $\Lambda\Lambda$ system with
$J^P=0^+$. It then suggests that a deeply bound H-particle should not exist. We
also compare our approach with other models employing different hyperfine
interactions between quarks in the nonperturbative regime of QCD.


title: Dynamical supersymmetry breaking and unification of couplings

abstract:
  We consider the possibility of unification of the Supersymmetric Standard
Model gauge groups with those of the dynamical supersymmetry breaking (DSB)
sector in theories with gauge mediated supersymmetry breaking. We find
constraints on the DSB gauge group beta function that come from unification of
the gauge coupling constants of the two sectors. These constraints are
satisfied by a fairly wide class of models. We discuss possible unification
scenarios in the context of a simple model.


title: Neutrino masses and mixing from neutrino oscillation data

abstract:
  We discuss what information about the neutrino mass spectrum and the elements
of the neutrino mixing matrix can be inferred from the results of neutrino
oscillation experiments. The cases of three and four massive neutrinos are
considered. It is shown that the general characteristics of the neutrino mixing
matrix are quite different from those of the quark mixing matrix.


title: LEP, SLC and the Standard Model

abstract:
  A simple way of deriving and analyzing electroweak radiative corrections to
the $Z$ boson decays is presented in the framework of the Standard Model. This
paper is an updated and revised version of a plenary talk given at the Second
Sakharov Conference; Lebedev Physical Institute, Moscow, May 20-24, 1996.


title: Photon-Photon total inelastic cross-section

abstract:
  We discuss predictions for the total inelastic gamma-gamma cross-section and
their model dependence on the input parameters. We compare results from a
simple extension of the Regge Pomeron exchange model as well as predictions
from the eikonalized mini-jet model with recent LEP data.


title: On the effective interaction in the light-cone QCD-Hamiltonian

abstract:
  The canonical front form Hamiltonian for non-Abelian SU(N) gauge theory in
3+1 dimensions is mapped non-perturbatively on an effective Hamiltonian which
acts only in the Fock space of a quark and an antiquark. Emphasis is put on
dealing with the many-body aspects of gauge field theory, and it is shown
explicitly how the higher Fock-space amplitudes can be retrieved
self-consistently from solutions in the $q\bar q$-space. The approach is based
on the novel method of iterated resolvents and on discretized light-cone
quantization, driven to the continuum limit. It is free of the usual
perturbative Tamm-Dancoff truncations in particle number and coupling constant,
and respects all symmetries of the Lagrangian including covariance and gauge
invariance. It is emphasized that vertex regularization as opposed to
Fock-space regularization allows an explicit renormalization, which yields
linear confinement. The string constant must be determined from experiment.


title:
Diffractive meson production from virtual photons with odd charge-parity
  exchange

abstract:
  We calculate the cross section of diffractive charge-parity C=+1 neutral
meson production in virtual photon proton collision at high energies. Due to
the opposite C-parities of photon and meson M (M = eta_C, pi^0, a_2) this
process probes the t-channel C=-1 odderon exchange which is described here as
noninteracting three-gluon exchange. Estimates for the cross section of the
inelastic diffractive process gamma^* p -> eta_C X_p are presented. The total
cross section of diffractive \eta_C meson photoproduction is found to be 47 pb.
The cross sections for the diffractive production of light mesons (pi^0, a_2)
in \gamma^* p collisions are of the same order if the photon virtuality Q^2 is
m^2_C.


title:
Fusion of strings vs. percolation and the transition to the quark-gluon
  plasma

abstract:
  In most of the models of hadronic collisions the number of exchanged colour
strings grows with energy and atomic numbers of the projectile and target. At
high string densities interaction between them should melt them into the
quark-gluon plasma state. It is shown that under certain assumptions about the
the string interaction, a phase transition to the quark gluon plasma indeed
takes place in the system of many colour strings. It may be of the first or
second order (percolation), depending on the particular mechanism of the
interaction. The critical string density is about unity in both cases. The
critical density may have been already reached in central Pb-Pb collisions at
158 A GeV.


title: Testing CPT with Anomalous Magnetic Moments

abstract:
  A theoretical framework is introduced that describes possible CPT-violating
effects in the context of quantum electrodynamics. Experiments comparing the
anomalous magnetic moments of the electron and the positron can place tight
limits on CPT violation. The conventional figure of merit adopted in these
experiments, involving the difference between the corresponding $g$ factors, is
shown to provide a misleading measure of the precision of CPT limits. We
introduce an alternative figure of merit, comparable to one commonly used in
CPT tests with neutral mesons. To measure it, a straightforward extension of
current experimental procedures is proposed. With current technology, a CPT
bound better than about one part in $10^{20}$ is attainable.


title: Leptoproduction of J/psi

abstract:
  We study leptoproduction of $J/\psi$ at large $Q^2$ within the
nonrelativistic QCD (NRQCD) factorization formalism. The cross section is
dominated by color-octet terms that are of order $\alpha_s$. The color-singlet
term, which is of order $\alpha^2_s$, is shown to be a small contribution to
the total cross section. We also calculate the tree diagrams for color-octet
production at order $\alpha^2_s$ in a region of phase space where there is no
leading color-octet contribution. We find that in this regime the color-singlet
contribution dominates. We argue that non-perturbative corrections arising from
diffractive leptoproduction, higher twist effects, and higher order terms in
the NRQCD velocity expansion should be suppressed as $Q^2$ is increased.
Therefore, the color-octet matrix elements $< {\cal O}_8^{\psi}(^1S_0)>$ and
$<{\cal O}_8^{\psi}(^3P_0)>$ can be reliably extracted from this process.
Finally, we point out that an experimental measurement of the polarization of
leptoproduced $J/\psi$ will provide an excellent test of the NRQCD
factorization formalism.


title:
Renormalization scheme dependence and the problem of determination of
  alpha_s and the condensates from the semileptonic tau decays

abstract:
  The QCD corrections to the moments of the invariant mass distribution in the
semileptonic $\tau$ decays are considered. The effect of the renormalization
scheme dependence on the fitted values of alpha_s(m^2_tau) and the condensates
is discussed, using a simplified approach where the nonperturbative
contributions are approximated by the dimension six condensates. The fits in
the vector and the axial-vector channel are investigated in the next-to-leading
and the next-to-next-to-leading order. The next-to-next-to-leading order
results are found to be relatively stable with respect to change of the
renormalization scheme. A change from the MS-bar scheme to the minimal
sensitivity scheme results in the reduction of the extracted value of
alpha_s(m^2_tau) by 0.01.


title:
Resummation of (-B(0) Alpha-s)**N Corrections to the Photon - Meson
  Transition Form-Factor Gamma* + Gamma ---> Pi0

abstract:
  We have resummed all the (-b_0 alpha_s)^n contributions to the photon-meson
transition form factor F_{gamma pi}. To do this, we have used the assumption of
`naive nonabelianization' (NNA). Within NNA, a series in (N_f alfa_s)^n is
interpreted as a series in (-b_0 alpha_S)^n by means of the restoration of the
full first QCD beta-function coefficient -b_0 by hand. We have taken into
account corrections to the leading order coefficient function and to the
evolution of the distribution function. Due to conformal constraints, it is
possible to find the eigenfunctions of the evolution kernel. It turns out that
the nondiagonal corrections are small, and neglecting them we obtained a
representation for the distribution function with multiplicatively renormalized
moments. For a simple shape of the distribution function, which is close to the
asymptotic shape, we find that the radiative correction decrease the LO by 30 %
and the uncertainty in the resummation lies between 10 % and 2 % for Q^2
between 2 and 10 GeV^2.


title: A new look at hadronic B decays

abstract:
  We present a detailed study of non-leptonic two-body decays of B mesons based
on a generalized factorization hypothesis. We discuss the structure of
non-factorizable corrections and present arguments in favour of a simple
phenomenological description of their effects. We discuss tests of the
factorization hypothesis and show how it may be used to determine unknown decay
constants. In particular, we obtain f_{D_s}=(234\pm 25) MeV and
f_{D_s^*}=(271\pm 33) MeV.


title: Field theory approach to K0-K0bar and B0-B0bar systems

abstract:
  Quantum field theory provides a consistent framework to deal with unstable
particles. We present here an approach based on field theory to describe the
production and decay of unstable $K^0-\bar{K^0}$ and $B^0-\bar{B^0}$ mixed
systems. The formalism is applied to compute the time evolution amplitudes of
$K^0$ and $\bar{K^0}$ studied in DAPHNE and CPLEAR experiments. We also
introduce a new set of parameters that describe CP violation in $ K \to \pi\pi$
decays without recourse to isospin decomposition of the decay amplitudes.


title: Measuring Z-gamma-Higgs vertex effects at e-gamma linear colliders

abstract:
  The one-loop process e,gamma->e,h for intermediate Higgs masses is
considered. Exact cross sections for unpolarized and longitudinally polarized
beams are computed and found to be more than two orders of magnitude larger
than the rates for the crossed process e,e->gamma,h, in the energy range
\sqrt{s}=(0.5-2) TeV. We show that, apart from being competitive with the
gamma,gamma->H process for testing the one-loop gamma-gamma-H vertex, by
requiring a final electron tagged at large angle the channel e,gamma->e,h
provides an excellent way of testing the Z-gamma-H vertex.


title: Searching for New Physics in Rare $B \to \tau$ Decays

abstract:
  The rare decays {$B^- \to \tau \bar\nu$}, \mbox{$B \to \tau^+ \tau^-$}, {$b
\to X \nu \bar\nu$} and \mbox{$b \to X \tau^+ \tau^-$} all contain third
generation leptons in the final state, and hence are sensitive to new physics
that couples more strongly to the third family. We present model independent
expressions for these decays that can be useful to study several types of new
physics effects. We concentrate on supersymmetric models without R-parity and
without lepton number. We also assume a horizontal U(1) symmetry with fermion
horizontal charges chosen to explain the magnitude of fermion masses and quark
mixing angles. This allows us to estimate the order of magnitude of the new
effects, and to derive numerical predictions for the various decay rates and
for the forward-backward asymmetry and the $\tau$ polarization components
measurable in \mbox{$b \to X \tau^+ \tau^-$}. In some cases the branching
ratios are enhanced by more than one order of magnitude, rendering foreseeable
their detection at upcoming B-factories. We also discuss how a measurement of
asymmetries in \mbox{$b \to X \tau^+ \tau^-$} can be crucial in distinguishing
between different sources of new physics.


title:
Schemes of neutrino mixing from the results of neutrino oscillation
  experiments

abstract:
  The mixing of three and four massive neutrinos is considered. It is shown
that the neutrino oscillation data are not compatible with a hierarchy of
couplings in the three-neutrino case. In the case of four neutrinos, a
hierarchy of masses is not favored by the data. Only two schemes with two pairs
of close masses separated by a gap of the order of 1 eV can accommodate the
results of all experiments. If the existing indications in favor of neutrino
oscillations will be confirmed, it will mean that the general features of
neutrino mixing are quite different from those of quark mixing.


title: Radiation Zeros at HERA - More About Nothing

abstract:
  The process $eq \to eq +\gamma$ exhibits radiation zeros, i.e. configurations
of the final-state particles for which the scattering amplitude vanishes. We
study these zeros for both $e^+u$ and $e^+d$ scattering. The latter exhibits a
type of zero which to our knowledge has not previously been identified. The
observability of radiation zeros at HERA is discussed.


title: Determinations of Standard Model Parameters from Lattice QCD

abstract:
  In this talk I review some recent results from lattice QCD calculations which
aim to a more accurate determination of the Standard Model parameters in the
quark sector. After a review of our current knowledge of these parameters, I
present lattice results for the strange, charm and bottom quark masses, the CKM
matrix element $V_{ub}$ and the complex CKM phase $\delta$, which induces CP
violation effects in the Standard Model with three generations.


title: Deep inelastic events containing two forward jets at HERA

abstract:
  We use the BFKL equation to calculate the rate of deep inelastic scattering
events containing two forward jets (adjacent to the proton remnants) at HERA.
We compare the production of two forward jets with that of only one forward jet
(the "Mueller" process). We obtain a stable prediction for this two to one jet
ratio, which may serve as a measure of the BFKL vertex function.


title: On The Possible Detection Of Massive Stable Exotic Particles At The LHC

abstract:
  The possible detection of massive quasi-stable exotic particles at the high
luminosity hadronic colliders is discussed. In the coming ten years the LHC,
now under preparation, has the best opportunity to observe them at the TeV
scale. The present design of the ATLAS detector,that has been almost
irreversibly decided, may turn out to be flexible enough to allow the detection
of this interesting class of exotic particles. The trigger acceptance, the
track reconstruction and the particle identification are studied. The necessity
of a good measurement of the ionization loss in the muon sector of the
detectors is recommended.


title:
Three channel model of meson-meson scattering and scalar meson
  spectroscopy

abstract:
  New solutions on the scalar -- isoscalar $\pi\pi$ phase shifts are analysed
together with previous $K\bar{K}$ results using a separable potential model of
three coupled channels ($\pi\pi$, $K\bar{K}$ and an effective $2\pi 2\pi$
system). Model parameters are fitted to two sets of solutions obtained in a
recent analysis of the CERN-Cracow-Munich measurements of the $\pi^-
p_{\uparrow} \to \pi^+ \pi^- n$ reaction on a polarized target. A relatively
narrow (90 -- 180 MeV) scalar resonance $f_0(1400-1460)$ is found, in contrast
to a much broader ($\Gamma \approx 500$ MeV) state emerging from the analysis
of previous unpolarized target data.


title: Supersymmetry and Inflation

abstract:
  A variant of hybrid inflation which is applicable in a wide class of
supersymmetric grand unified models and reproduces the observed temperature
perturbations of cosmic background radiation with natural values of the
parameters is presented. The theory is consistent with the unification of the
minimal supersymmetric standard model gauge couplings as measured at LEP. The
termination of inflation is smooth and does not produce any topological
defects. Numerical investigation of the cosmological evolution of the system
shows that for almost all initial values of the fields we do get an adequate
amount of inflation. Finally, the "reheating" process following inflation and
the production of the baryon asymmetry of the universe via a primordial lepton
asymmetry are briefly discussed and some important implications for right
handed neutrino Majorana masses are investigated.


title: Muon Colliders: The Machine and The Physics

abstract:
  A review of muon colliders is presented. Basic features of the accelerator
and detector are outlined, and the very exciting physics prospects are
reviewed.


title: The anthropic principle and the mass scale of the Standard Model

abstract:
  In theories in which different regions of the universe can have different
values of the the physical parameters, we would naturally find ourselves in a
region which has parameters favorable for life. We explore the range of
anthropically allowed values of the mass parameter in the Higgs potential,
$\mu^2$. For $\mu^2<0$, the requirement that complex elements be formed
suggests that the Higgs vacuum expectation value $v$ must have a magnitude less
than 5 times its observed value. For $\mu^2>0$, baryon stability requires that
$|\mu|<<M_P$, the Planck Mass. Smaller values of $|\mu^2|$ may or may not be
allowed depending on issues of element synthesis and stellar evolution. We
conclude that the observed value of $\mu^2$ is reasonably typical of the
anthropically allowed range, and that anthropic arguments provide a plausible
explanation for the closeness of the QCD scale and the weak scale.


title:
Radiative Correction to the Nuclear-Size Effect and Hydrogen-Deuterium
  Isotopic Shift

abstract:
  The radiative correction to the nuclear charge radius contribution to the
Lamb shift of order $\alpha(Z\alpha)^5m_r^3<r^2>$ is calculated. In view of the
recent high precision experimental data, this theoretical correction produces a
significant contribution to the hydrogen-deuterium isotopic shift.


title:
Is J/psi-Nucleon Scattering Dominated by the Gluonic van der Waals
  Interaction?

abstract:
  The gluon-exchange contribution to $J/\psi$-nucleon scattering is shown to
yield a sizeable scattering length of about -0.25 fm, which is consistent with
the sparse available data. Hadronic corrections to gluon exchange which are
generated by $\rho\pi$ and $D\bar D$ intermediate states of the $J/\psi$ are
shown to be negligible. We also propose a new method to study $J/\psi$-nucleon
elastic scattering in the reaction $\pi^+ d\to J/\psi p p$.


title: Angular ordering and small-x evolution

abstract:
  This talks examines the effect of angular ordering on the small-x evolution
of the unintegrated gluon distribution, and discusses the characteristic
function for the CCFM equation, as well as some preliminary results on
final-state properties.


title: Diffraction in DIS and Elsewhere

abstract:
  I review some of the results presented in the working group on diffraction at
DIS97, with a particular emphasis on the theory of diffractive hard scattering.


title: Rho-Omega Mixing and the Pion Form Factor in the Time-like Region

abstract:
  We determine the magnitude, phase, and $s$-dependence of $\rho$-$\omega$
``mixing'' in the pion form factor in the time-like region through fits to
$e^+e^- \ra \pi^+ \pi^-$ data. The associated systematic errors in these
quantities, arising from the functional form used to fit the $\rho$ resonance,
are small. The systematic errors in the $\rho$ mass and width, however, are
larger than previously estimated.


title:
Composite Intermediary and Mediator Models of Gauge-Mediated
  Supersymmetry Breaking

abstract:
  We discuss gauge-mediated models which employ a tree-level mass term in the
superpotential. We give explicit composite realizations in which the mass terms
are not fundamental. Instead, they arise as effective terms in the
superpotential from confining gauge dynamics.


title: HERA Anomaly and Hard Charm in the Nucleon

abstract:
  We explore the possibility that the excess neutral and charged current events
seen by the H1 and ZEUS Collaborations at HERA at large x and Q^2 could arise
from a hard charm component of the nucleon. While the symmetric intrinsic charm
hypothesis is unable to account for the HERA anomaly, a non-symmetric charm
distribution generated non-perturbatively, for which c-bar is much harder than
c, can produce significant enhancement of cross sections at the HERA
kinematics.


title: Poincare Covariant Quark Models of Baryon Form Factors

abstract:
  Poincare covariant quark models of the the nucleon, the $\Delta$ resonance
and their excitations are explored. The baryon states are represented by
eigenfunctions of the four-velocity and a confining mass operator, which
reproduces the empirical spectrum up to $\sim$ 1700 MeV to an accuracy of $\sim
6%$. Models of constituent quark currents provide the relations between
ground-state properties and transition amplitudes.


title: Minijets and the Two-Body Parton Correlation

abstract:
  A large number of double parton scatterings have been recently measured by
CDF. The double parton scattering process measures $\sigma_{eff}$, a non
perturbative quantity related to the hadronic transverse size and with the
dimensions of a cross section. The actual value measured by CDF is considerably
smaller as compared with the naive expectation, namely the value of the
inelastic non diffractive cross section. The small value of $\sigma_{eff}$ may
be an effect of the hadron structure in transverse plane. We discuss the
problem by taking into account, at all orders, the two-body parton correlations
in the many-body parton distributions.


title: Irreducible part of the next-to-leading BFKL kernel

abstract:
  On the basis of previous work by Fadin, Lipatov, and collaborators, and of
our group, we extract the "irreducible" part of the next-to-leading (NL) BFKL
kernel, we compute its (IR finite) eigenvalue function, and we discuss its
implications for small-x structure functions. We find consistent running
coupling effects and sizable NL corrections to the Pomeron intercept and to the
gluon anomalous dimension. The qualitative effect of such corrections is to
smooth out the small-x rise of structure functions at low values of Q2. A more
quantitative analysis will be possible after the extraction of some additional,
energy-scale dependent contributions to the kernel, which are not treated here.


title: Decays of spacelike neutrinos

abstract:
  In this paper we consider the hypothesis that neutrinos are fermionic
tachyons with helicity 1/2. We propose an effective model of interactions of
these neutrinos and analyze dominant effects under the above hypothesis: the
three-body neutrino decay, the radiative decay and briefly discuss beta-decay
with tachyonic antineutrino. We calculate the corresponding amplitudes and the
mean life time for decays, as well as the differential decay width. In addition
we apply the neutrino three-body decay to the solar neutrino problem and we
obtain a remarkable change of energy spectrum of the neutrino flux at the Earth
ground (assuming no neutrino oscillation). We compare the results with the
Standard Solar Model predictions and solar neutrino experiments to estimate an
upper bound for the taonic neutrino.


title:
Worldline approach to Sudakov-type form factors in non-Abelian gauge
  theories

abstract:
  We calculate Sudakov-type form factors for isolated spin-1/2 particles
(fermions) entering non-Abelian gauge-field systems. We consider both the on-
and the off-mass-shell case using a methodology which rests on a worldline
casting of field theories. The simplicity and utility of our approach derives
from the fact that we are in a position to make, a priori, a more transparent
separation (factorization), with respect to a given scale, between short- and
long-distance physics than diagramatic methods.


title: Unified QCD Description of Hadron and Jet Multiplicities

abstract:
  The evolution equation for parton multiplicities in quark and gluon jets
which takes into account the soft gluon interference is solved numerically
using the initial conditions at threshold. If the k_T-cutoff Q_c is lowered
towards the hadronic scale Q_0 of a few hundred MeV, the jets are fully
resolved into hadrons. Both hadron and jet multiplicities in e+e- annihilation
are well described with a common normalization. Evidence is presented within
this perturbative approach that the coupling \alpha_s(k_T) rises by an order of
magnitude when approaching the low energy region. The ratio of hadron
multiplicities in gluon and quark jets is found smaller than in previous
approximate solutions of the evolution equation.


title:
Two loops calculation in chiral perturbation theory and the
  unitarization program of current algebra

abstract:
  In this paper we compare two loop Chiral Perturbation Theory (ChPT)
calculation of pion-pion scattering with the unitarity second order correction
to the current algebra soft-pion theorem. It is shown that both methods lead to
the same analytic structure for the scattering amplitude.


title:
Charged Higgs Boson and Stau Phenomenology in the Simplest R-Parity
  Breaking Model

abstract:
  We consider the charged scalar boson phenomenology in the simplest effective
low-energy R-parity breaking model characterized by a bilinear violation of
R-parity in the superpotential. This induces a mixing between staus and the
charged Higgs boson. We show that the charged Higgs boson mass can be lower
than expected in the MSSM, even before including radiative corrections. We also
study the charged scalar boson decay branching ratios and show that the
R-parity violating decay rates can be comparable or even bigger than the
R-parity conserving ones. Moreover, if the stau is the LSP it will have only
decays into standard model fermions. These features could have important
implications for charged supersymmetric scalar boson searches at future
accelerators.


title: Evaluation of Multiloop Diagrams via Lightcone Integration

abstract:
  We present a systematic method to determine the dominant regions of internal
momenta contributing to any two-body high-energy near-forward scattering
diagram. Such a knowledge is used to evaluate leading high-energy dependences
of loop diagrams. It also gives a good idea where dominant multiparticle cross
sections occur.


title: Oblate Skyrmions

abstract:
  The spherically symmetric hedgehog ansatz used in the description of the
skyrmion is believed to be inadequate for the rotational states such as the
nucleon (I=J=1/2) and the Delta (I=J=3/2) due to centrifugal forces. We study
here a simple alternative: an oblate spheroidal solution which leads to lower
masses for these baryons. As one might expect, the shape of the solution is
flatter as one increases I=J whether the size of the soliton is allowed to
change or not.


title:
The Solar Neutrino Problem in the Presence of Flavor Changing Neutrino
  Interactions

abstract:
  We study the effects of flavor changing neutrino interactions on the resonant
conversion of solar neutrinos. In particular, we describe how the regions in
the $Delta m^2 - sin^2 2theta$ plane that are consistent with the four solar
neutrino experiments are modified for different strengths of New Physics
neutrino interactions.


title: On-Shell Approach to Pion-Nucleon Physics

abstract:
  We discuss an on-shell approach to pion-nucleon physics that is consistent
order by order in a $1/f_{\pi}$ expansion with the chiral reduction formula,
crossing, and relativistic unitarity. A number of constraints between the
on-shell low-energy parameters are derived at tree level in the presence of the
pion-nucleon sigma term, and found to be in fair agreement with experiment. We
analyze the nucleon form factors, and the $\pi N\to \pi N$ scattering amplitude
to one-loop, as well as $\pi N\to\pi\pi N$ to tree level. We use the latter to
derive a new constraint for the pion-nucleon sigma term at threshold. We
compare our results to both relativistic and non-relativistic chiral
perturbation theory, and discuss the convergence character of the expansion in
light of experiment.


title:
Squeezed Gluon Condensate and Quark Confinement in the Global Color
  Model of QCD

abstract:
  We discuss how the presence of a squeezed gluon vacuum might lead to quark
confinement in the framework of the global colour model of QCD. Using reduced
phase space quantization of massive vector theory we construct a Lorentz
invariant and colourless squeezed gluon condensate and show that it induces a
permanent, nonlocal quark interaction (delta-function in 4-momentum space),
which according to Munczek and Nemirovsky might lead to quark confinement. Our
approach makes it possible to relate the strength of this effective confining
quark interaction to the strength of the physical gluon condensate.


title: Unification predictions

abstract:
  The unification of gauge couplings suggests that there is an underlying
(supersymmetric) unification of the strong, electromagnetic and weak
interactions. The prediction of the unification scale may be the first
quantitative indication that this unification may extend to unification with
gravity. We make a precise determination of these predictions for a class of
models which extend the multiplet structure of the Minimal Supersymmetric
Standard Model to include the heavy states expected in many Grand Unified
and/or superstring theories. We show that there is a strong cancellation
between the 2-loop and threshold effects. As a result the net effect is smaller
than previously thought, giving a small increase in both the unification scale
and the value of the strong coupling at low energies.


title: Aspects of String unification

abstract:
  We consider the phenomenological implications of a class of compactified
string theories which naturally reproduces the flavour multiplet structure of
the Standard Model. The implications for gauge unification depends on which of
three possibilities is realised for obtaining light Higgs multiplets. The more
conventional one leads to predictions for the gauge couplings close to that of
the MSSM but with an increased value of the unification scale. The other two
cases offer a mechanism for bringing the prediction for the strong coupling
into agreement with the measured value while still increasing the unification
scale. The various possibilities lead to different expectations for the
structure of the quark masses.


title: Summing $O(\beta_0^n \alpha_s^{n+1})$ Corrections to Top Quark Decays

abstract:
  Order $\beta_0^n \alpha_s^{n+1}$ QCD corrections to top quark decays into
$W^+$ and $H^+$ bosons are computed to all orders in perturbation theory.
Predictions for the radiative corrections to the top quark width are compared
with the estimates from BLM scale setting procedures. The results of the
summation are shown to greatly improve understanding of higher order
corrections in the limit $m_W,~m_H \to m_t$, where the BLM scale setting method
is known to fail. Attempts to reduce nonperturbative error by substituting the
running mass for the pole mass in the expression for the decay are shown to
fail in the limit $m_W,~m_H \to m_t$ because of subtleties in the treatment of
phase space.


title:
Near-threshold Isospin Violation in the Pion Form Factor from Chiral
  Perturbation Theory

abstract:
  We examine the isospin violation in the timelike pion form factor near
threshold at next-to-leading order in the chiral expansion using the techniques
of Chiral Perturbation Theory. This next-to-leading order contribution contains
the first nonvanishing isospin violation. This isospin violation is found to be
very small near threshold. In particular, the isospin violation at threshold is
found to be of order 10^-4, which should be compared with the few percent level
seen in the vector meson resonance region.


title: Hybrid Inflation from Supersymmetric SU(5)

abstract:
  A scheme of hybrid inflation is considered in the framework of the minimal
supersymmetric SU(5) model with an extra singlet. The relevant role of the
cubic term in the adjoint representation in the renormalizable superpotential
is pointed out in order to have a quite wide region of initial conditions
compatible with inflation efficiency, monopole density and perturbations
constraint.


title:
Phenomenological $ \pi N \to \pi \pi N $ Amplitude and Analysis of Low
  Energy Data on Total Cross Sections and 1--D Distributions

abstract:
  We develop the phenomenological amplitude of the $\pi N \to \pi \pi N$
reaction describing the exchanges of $\Delta$ and $N_{*}$ along with the OPE
mechanism. The contribution of the latter contains 4 independent low energy
parameters (up to $O(k^{4})$ order). The terms of the polynomial background are
added to stand for far resonances and for contact terms originating from the
off-mass-shell interactions. These terms are introduced with the account of
isotopic, crossing, $ C $, $ P $ and $ T $ symmetries of strong interactions.
The data consisting of total cross sections in the energy region $ 0.300 \le
P_{Lab} \le 500 $~MeV/c and 1D distributions from the bubble-chamber
experiments for three reaction channels were undergoing fittings to determine
free parameters of the amplitude. The best solutions are characterized by $
\chi^{2}_{DF} = $ 1.16. At the considered energies the isobar exchanges are
found to be more important than OPE. The obtained solutions reveal the need in
more precise data and/or in polarization measurements because of large
correlations of isobar parameters with the OPE ones. The theoretical solutions
were used for modeling the Chew-Low extrapolation and the Olsson-Turner
threshold approach. It is shown that the noncritical application of the former
results in 100% theoretical errors, the extracted values being in fact the
random numbers. The results of the Olsson-Turner method are characterised by
significant systematic errors coming from unknown details of isobar physics.


title: Neutrino Oscillations from String Theory

abstract:
  We derive the character of neutrino oscillations that results from a model of
equivalence principle violation suggested recently by Damour and Polyakov as a
plausible consequence of string theory. In this model neutrino oscillations
will take place through interaction with a long range scalar field of
gravitational origin even if the neutrinos are degenerate in mass. The energy
dependence of the oscillation length is identical to that in the conventional
mass mixing mechanism. This possibility further highlghts the independence of
and need for more exacting direct neutrino mass measurements together with a
next generation of neutrinoless double beta decay experiments.


title: The Spin and Flavor Content of Intrinsic Sea Quarks

abstract:
  The intrinsic quark-antiquark pairs generated by the minimal energy
nonperturbative meson-baryon fluctuations in the nucleon sea provide a
consistent framework for understanding a number of empirical anomalies observed
in the deep inelastic quark-parton structure of nucleons: the flavor asymmetry
of the nucleon sea implied by the violation of Gottfried sum rule, the proton
spin problem implied by the violation of the Ellis-Jaffe sum rule, and the
outstanding conflict between two different determinations of the strange quark
sea in the nucleon.


title:
The Chromoelectric and Purely Gluonic Operator Contributions to the
  Neutron Electric Dipole Moment in N=1 Supergravity

abstract:
  A complete one loop analysis of the chromoelectric dipole contribution to the
electric dipole moment (edm) of the quarks and of the neutron in N=1
supergravity including the gluino, chargino and neutralino exchange
contributions and exhibiting the dependence on the two CP violating phases
allowed in the soft SUSY breaking sector of minimal supergravity models is
given. It is found that in significant parts of the supergravity parameter
space the chromoelectric dipole contribution to the neutron edm is comparable
to the contribution from the electric dipole term and can exceed the
contribution of the electric dipole term in certain regions of the parameter
space. An analysis of the contribution of Weinberg's purely gluonic CP
violating dimension six operator within supergravity unification is also given.
It is found that this contribution can also be comparable to the contribution
from the electric dipole term in certain regions of the supergravity parameter
space.


title: Constraints on Semileptonic Form-factors from Dispersive Sum Rules

abstract:
  I briefly discuss the derivation of dispersive sum rules constraining
semileptonic form-factors. I outline the use of these constraints in the
context of charmless semileptonic decays and suggest how, in combination with
other theoretical and experimental information, they may reduce the
uncertainties in the extraction of $V_{ub}$.


title: Magnetic Moments of $\Delta^{++}$ and $\Omega^-$ from QCD Sum Rules

abstract:
  QCD sum rules for the magnetic moments of $\Delta^{++}$ and $\Omega^-$ are
derived using the external field method. They are analyzed by a Monte-Carlo
based procedure, using realistic estimates of the QCD input parameters. The
results are consistent with the measured values, despite relatively large
errors that can be attributed mostly to the poorly-known vacuum susceptibility
$\chi$. It is shown that a 30% level accuracy can be achieved in the derived
sum rules, provided the QCD input parameters are improved to the 10% level.


title: Global Study of Electron-Quark Contact Interactions

abstract:
  We perform a global fit of data relevant to $eeqq$ contact interactions,
including deep inelastic scattering at high $Q^2$ from ZEUS and H1, atomic
physics parity violation in Cesium from JILA, polarized $e^-$ on nuclei
scattering experiments at SLAC, Mainz and Bates, Drell-Yan production at the
Tevatron, the total hadronic cross section $\sigma_{had}$ at LEP, and
neutrino-nucleon scattering from CCFR. With only the new HERA data, the
presence of contact interactions improves the fit compared to the Standard
Model. When other data sets are included, the size of the contact contributions
is reduced and the overall fit represents no real improvement over the Standard
Model.


title: Some Issues in Gauge Mediation

abstract:
  After briefly reviewing some arguments in favor of high scale and low scale
supersymmetry breaking, I discuss a possible solution of the $\mu$-problem of
gauge mediated models.


title:
Direct CP Violation in $B^\pm\to\rho^\pm\pi^+\pi^-$ in the
  $\rho^0$-$\omega$ Interference Region

abstract:
  We study direct CP violation in $B^\pm \to \rho^\pm\rho^0(\omega) \to
\rho^\pm\pi^+\pi^-$ and focus specifically on the rate asymmetry in the
$\rho^0$-$\omega$ interference region. Here the strong phase is dominated by
isospin violation, so that it can be essentially determined by $e^+e^- \to
\rho^0 (\omega) \to \pi^+\pi^-$ data. We find the CP-violating asymmetry to be
of the order of 20% at the $\omega$ invariant mass. Moreover, it is robust with
respect to the estimable strong-phase uncertainties, permitting the extraction
of $\sin\alpha$ from this channel.


title: 3d effective theories for the Standard Model and extensions

abstract:
  The construction and analysis of 3d effective theories for the description of
the thermodynamics of the cosmological electroweak phase transition are
reviewed. For the Standard Model and for the MSSM with stops somewhat heavier
than the top, the effective theory is 3d SU(2)+Higgs, and the transition is
strong enough for baryogenesis at no Higgs mass for the Standard Model, and up
to m_H ~ 80 GeV for the MSSM. For lighter stops, the effective theory is
SU(3)xSU(2) + two scalars and the transition could be strong enough up to m_H ~
100 GeV. However, a lattice study in 3d is needed to confirm the last bound.


title: CP violating anomalous trilinear gauge couplings from B-> K^*l^+l^-

abstract:
  We study the contributions of the CP violating anomalous WW-gamma
interactions to b->s l^+ l^-. We obtain cutoff independent results on tilde
kappa and tilde lambda, by constructing an asymmetry for the process
B->K^*l^+l^-, where the B and B bar events are added. We show that a sample of
10^4 B-> K^*e^+e^- events, can yield a bound
  |tilde kappa| < 0.42 at 90% C.L., which is much tighter than the recent
constraint from D0.


title: Flavor-Nonconservation and CP-Violation with Singlet Quarks

abstract:
  Some aspects are considered on the flavor-nonconservation and $ CP
$-violation arising from the quark mixings with singlet quarks. In certain
models incorporating the singlet quarks, the contributions of the quark
couplings to the neutral Higgs fields may become more significant than those of
the neutral gauge interactions. Then, they would provide distinct signatures
for new physics beyond the standard model in various flavor-nonconserving and $
CP $-violating processes such as the neutron electric dipole moment, $ D^0 $-$
{\bar D}^0 $, $ K^0 $-$ {\bar K}^0 $, $ B^0 $-$ {\bar B}^0 $, $ b \to s \gamma
$, and so on.


title:
Instanton Contribution to Polarized and Unpolarized Gluon Distribution
  in Nucleon

abstract:
  The contribution of the anomalous quark-gluon interaction induced by
instantons to the polarized and unpolarized gluon distributions in nucleon is
estimated. It is shown that this interaction leads to negative gluon
polarization in nucleon.


title: Baryogenesis, 30 Years after

abstract:
  A review of the basic principles of baryogenesis is given. Baryogenesis in
heavy particle decays as well as electroweak, SUSY-condensate, and spontaneous
baryogenesis are discussed. The models of abundant creation of antimatter in
the universe are briefly reviewed.


title: Summary of Working Group I: Hadron Structure

abstract:
  A summary is given on the main aspects which were discussed by the working
group. They include new results on the deep inelastic scattering structure
functions $F_2, xF_3, F_L$ and $F_2^{c\bar{c}}$ and their parametrizations, the
measurement of the gluon density, recent theoretical work on the small $x$
behavior of structure functions, theoretical and experimental results on
$\alpha_s$, the direct photon cross section, and a discussion of the event
rates in the high $p_T$ range at Tevatron and the high $Q^2$ range at HERA, as
well as possible interpretations.


title:
The non-perturbative three-point vertex in massless quenched QED and
  perturbation theory constraints

abstract:
  Dong, Munczek and Roberts have shown how the full 3-point vertex that appears
in the Schwinger-Dyson equation for the fermion propagator can be expressed in
terms of a constrained function $W_1$ in massless quenched QED. However, this
analysis involved two key assumptions: that the fermion anomalous dimension
vanishes in the Landau gauge and that the transverse vertex has a simplified
dependence on momenta. Here we remove these assumptions and find the general
form for a new constrained function $U_1$ that ensures the multiplicative
renormalizability of the fermion propagator non-perturbatively. We then study
the restriction imposed on $U_1$ by recent perturbative calculations of the
vertex and compute its leading logarithmic expansion. Since $U_1$ should reduce
to this expansion in the weak coupling regime, this should serve as a guide to
its non-perturbative construction. We comment on the perturbative realization
of the constraints on $U_1$.


title: Leptoquark production at the Tevatron

abstract:
  I discuss the production of leptoquarks in $p\bar{p}$ collisions at the
Fermilab Tevatron. Evaluated on the basis of a recent next-to-leading order
calculation, the combined D0 and CDF leptoquark searches lead to a
parameter-free lower mass bound of about $\ms \simgt 240$ GeV for scalar
leptoquarks or squarks decaying solely to a first generation charged lepton
plus quark. These results provide very stringent constraints on any explanation
of the recently observed HERA excess events in terms of new particle
production.


title: New physics in a nutshell, or Q-ball as a power plant

abstract:
  Future experiments may discover new scalar particles with global charges and
couplings that allow for solitonic states. If the effective potential has flat
directions, the scalar VEV inside a large Q-ball can exceed the particle mass
by many orders of magnitude. Models with low-energy supersymmetry breaking
generically have both the scalars carrying some global charges, and the flat
directions. The Q-ball interior can, therefore, provide an environment for
exploring physics far beyond the TeV scale without the need for building
colliders of ever-increasing energies. Some Standard Model processes, otherwise
strongly suppressed, can also be studied inside the soliton, where the SU(2)
symmetry can be restored, and the quark confinement may be absent. Baryon
number violating processes catalyzed by the large VEV inside the Q-ball can
provide an inexhaustible energy resource.


title:
Probabilistic versus Field-Theoretical Description of Heavy Flavour
  Production off Nuclei

abstract:
  The absorptive corrections resulting from the rescattering of a heavy flavour
(the so-called nuclear absorption) are usually calculated with a probabilistic
formula valid only in the low energy limit. We extend this formula to all
energies using a quantum field theoretical approach. For charmonium and
bottonium we find that the absorptive corrections in the rigorous treatment are
very similar to the ones in the probabilistic approach. On the contrary, at
sufficiently high energy, open charm and bottom are absorbed as much as
charmonium and bottonium - in spite of the fact that their absorptive
cross-sections are zero, and therefore they are not absorbed in the
probabilistic model. At high enough energies there are also absorptive
corrections due to the shadowing of the nucleus structure function, which are
present for all systems including Drell-Yan pair production. These shadowing
corrections cancel in the low energy limit.


title: Constraints on Finite Soft Supersymmetry-Breaking Terms

abstract:
  Requiring the soft supersymmetry-breaking (SSB) parameters in finite
gauge-Yukawa unified models to be finite up to and including two-loop order, we
derive a two-loop sum rule for the soft scalar-masses. It is shown that this
sum rule coincides with that of a certain class of string models in which the
massive string states are organized into N=4 supermultiplets. We investigate
the SSB sector of two finite SU(5) models. Using the sum rule which allows the
non-universality of the SSB terms and requiring that the lightest superparticle
particleis neutral, we constrain the parameter space of the SSB sector in each
model.


title: Diffractive color-dipole nucleon scattering

abstract:
  We determine the diffractive scattering amplitude of a color-dipole on a
nucleon using a non-perturbative model of QCD which contains only parameters
taken from low-energy physics. This allows to relate specific features of the
confinement mechanisms with diffractive electro-production processes and
structure functions. The agreement with phenomenological data is satisfactory.


title: Inclusive CP Asymmetries in Semileptonic Decays of B Mesons

abstract:
  We estimate the sensitivity of single lepton CP violation measurements with
respect to that of traditional di-lepton measurements. We find that the
sensitivity of the single lepton method is better than that of the di-lepton
method. The achievable sensitivity with the currently available data is already
in the range relevant to standard model predictions. We also give general
expressions for inclusive decay time distributions on $\Upsilon 4S$ where the
other $B$ is not measured, which will be used to obtain time dependent
asymmetries. The expression is of general use whenever one deals with inclusive
time-dependent as well as time-integrated measurements in $\Upsilon(4S)\to
B^0\bar B^0$ where the final state of the other $B$ is not reconstructed or
when only the time difference is measured.


title: Reply to Comment on "Pulsar velocities and neutrino oscillations"

abstract:
  We have recently proposed an explanation for the birth velocities of pulsars
based on neutrino oscillations (hep-ph/9606428). One of the quantities, dN/dT,
was evaluated in the approximation of constant chemical potential for the
electrons. An alternative approximation based on the assumption Ye=const, used
by Qian (astro-ph/9705055), yields a somewhat higher prediction for the
magnetic field inside a neutron star. If the same input parameters are used,
the two approximations are in reasonable agreement, given the uncertainty in
the geometry of the magnetic field and the simplified picture of neutrino
emission that comes with the notion of a neutrinosphere.


title:
The solution to a multichannel Bethe potential and its application to
  pion-nucleus reactions

abstract:
  We solve a radial Schr\"odinger equation for the case of a multichannel
square well plus an exponential potential in one of the channels. The solution
is obtained by summing exactly the infinite terms of the perturbative series
for the evolution operator of the system. Analytical expressions for the
scattering matrix and the scattering length are given, a Deser-like formula
which connects approximate ground energies and scattering length is obtained
for a particular case. Possible physical applications of these results are
discussed briefly.

categories: hep-ph nucl-ex nucl-th physics.atom-ph quant-ph


title: Production of Charged Higgs Boson Pairs in Gluon-Gluon Collisions

abstract:
  The search for charged Higgs bosons, which are predicted in supersymmetric
theories, is difficult at hadron colliders if the mass is large. In this paper
we present the theoretical set-up for the production of charged Higgs boson
pairs at the LHC in gluon-gluon collisions: $pp -> gg -> H^+ H^-$. When
established experimentally, the trilinear couplings between charged and neutral
CP-even Higgs bosons, $H^+ H^- h^0$ and $H^+ H^- H^0$, can be measured.


title: CP-odd interaction of axion with matter

abstract:
  In the world with axion the precise measurement of gravitational force and
check of the equivalence principle at small distances, $\lambda\sim 1cm$ and
less, could provide an additional test of CP symmetry. Using the chiral
approach, we connect the strength of CP-odd axion-nucleon vertex with CP-odd
pion-nucleon coupling for color electric dipole moments of quarks as a low
energy source of CP violation. Strong limits on CP-odd coupling $g_{\pi NN}$
coming from atomic electric dipole moments show that gravitational experiments
are six orders of magnitude away from the sensitivity level needed to detect
axion-mediated forces.


title: Magnetic Catalysis in Quantum Electrodynamics

abstract:
  We derive the (Wilsonian) low energy effective Lagrangian for Quantum
Electrodynamics under external constant magnetic field by integrating out all
electrons except those in the lowest Landau level. We find the one-loop
effective Lagrangian contains a marginal four-Fermi interaction with anomalous
dimension, ${(\ln2)^2\over 2\pi^2}e^4$. Renormalization group analysis shows
that the four-Fermi interaction will break chiral symmetry in QED if the
external magnetic field is extremely strong, $B>10^{42}$ gauss, or if the
Landau gap, $\sqrt{|eB|}>6.5 \times 10^{10}$ GeV.


title: On Radiative CP Violation in (Supersymmetric) Two Higgs Doublet Models

abstract:
  We discuss the feasibility of spontaneous CP violation being induced by
radiative corrections in 2HDM's, emphasizing on a consistent treatment at
1-loop level. Specifically, we analyze the cases of gaugino/higgsino effect on
MSSM, and a new model proposed here with an extra, exotic, quark doublet. The
latter model is phenomenologically interesting. One conclusion is that some
fine tuning is in general needed for the scenario to work. The case for the new
model requires a tree level mass mixing between the two Higgses, which fits in
the standard SUSY picture. The fine tuning requires is then very moderate in
magnitude and in a way natural.


title: Superstring Phenomenology: An Overview

abstract:
  The different aspects of superstring phenomenology before and after 1995 are
briefly reviewed. (Contribution to the conference SUSY97)


title: An Introduction to Explicit R-Parity Violation

abstract:
  I discuss the theoretical motivations for R-parity violation, review the
experimental bounds and outline the main changes in collider phenomenology
compared to conserved R-parity. I briefly comment on the effects of R-parity
violation on cosmology.


title: The Quasi-Fixed MSSM

abstract:
  The infra-red fixed points are determined for all the parameters of the MSSM.
They dominate the renormalisation group running when the top-Yukawa is in the
quasi-fixed point regime (i.e. large at the GUT scale). We examine this
behaviour analytically, by solving the full set of one-loop renormalisation
group equations in the approximation that the electroweak contributions are
negligible, and also numerically. We find the quasi-fixed points for the
top-quark trilinear couplings; A_{U_{\alpha 3}} = A_{U_{3\alpha}}=-0.59 m_g
independently of the input parameters at the unification scale. All the
remaining parameters are significantly focused towards their true fixed points
at the weak scale. We examine how this increases the predictivity of the MSSM
in this regime.


title:
One-loop MSSM Contribution to the Weak Magnetic Dipole Moments of Heavy
  Fermions

abstract:
  The MSSM predictions at the one-loop level for the weak-magnetic dipole
moments of the $\tau$ lepton and the $b$ quark are analysed. The entire
supersymmetric parameter space is scannedwith the usual GUT constraint and
common squark and slepton mass parameters. The real part of $a^W_\tau$ is
dominated by the chargino contribution, being the same order as the SM one or
even larger in the high $\tan\beta$ region whereas the imaginary part, due to
Higgs boson diagrams, is negligible comparedto the SM value. The real part
of$a^W_b$ is controlled mainly by charginos andalso by gluinos, when the mixing
in the bottom squark sector is large, to yield, for high $\tan\beta$, a
contribution one order of magnitude largerthan the pure electroweak SM value
but a factor five smaller than the standard QCD contribution. The imaginary
part of $a^W_b$ is the same order as in the SM.


title:
NNLO QCD Analysis of CCFR data on $xF_3$ Structure Function and
  Gross-Llewellyn Smith Sum Rule with Higher Twist and Nuclear Corrections

abstract:
  A detailed NNLO QCD analysis of new CCFR data on the $xF_3$ structure
function including the target mass, higher twist and nuclear corrections was
performed and parametrizations of the perturbative and power terms of the
structure function were constructed. The results of QCD analysis of the
structure function were used to study the $Q^2-$dependence of the
Gross-Llewellyn Smith sum rule. The $\alpha_S/\pi-$expansion of $S_{GLS}(Q^2)$
was studied and parameters of the expansion were found to be $s_1=2.74\pm
0.01$, $s_2=-2.22\pm 0.23$, $s_3=-7.86\pm 1.74$ in a good agreement with the
perturbative QCD predictions for the Gross-Llewellyn Smith sum rule in the
next-to-leading and next-to-next-to-leading order.


title:
Gauge-Mediated Supersymmetry Breaking within the Dynamical Messenger
  Sector

abstract:
  We consider the idea of combining the supersymmetry breaking and messenger
sectors in models of gauge-mediated supersymmetry breaking. We discuss the
advantages and problems of such models, and present an existence proof by
constructing an explicit example. We explore in some detail the low-energy
supersymmetry-breaking dynamics and the generation of supersymmetry-breaking
soft masses of the standard model superpartners, and discuss many features
which are likely to be shared by more realistic models with dynamical
messengers.


title: Renormalizability of hot classical field theory

abstract:
  I discuss the possibility of using classical field theory to approximate hot,
real-time quantum field theory. I calculate, in a scalar theory, the classical
two point and four point function in perturbation theory. The counterterms
needed to make the classical correlation functions finite are dictated by the
superrenormalizability of the static theory. The classical expressions
approximate the quantum ones, when the classical parameters are chosen
according to the dimensional reduction matching rules. I end with an outlook to
gauge theories.


title: Theory of elastic vector meson production: some recent developments

abstract:
  I review some recent developments in the QCD description of elastic vector
meson production, focusing on issues like the meson wave function, the gluon
density in the proton, factorisation, the use of parton-hadron duality and the
nonperturbative vacuum.


title: Dynamical Supersymmetry Breaking

abstract:
  I review the motivation for dynamical supersymmetry breaking, the various
mechanisms which have been discovered, and the prospects for model building.


title: Phenomenology of LEP 2 Physics

abstract:
  Various aspects of physics at LEP 2 are reviewed from a phenomenological
point of view. We first discuss the search for Higgs bosons, which might be
relatively light if indications from the precision electroweak data and
supersymmetry are correct. Then WW physics is discussed, with particular
emphasis on the problems in measuring mW by the kinematic reconstruction of
events with purely hadronic final states. Finally, possible manifestations of
supersymmetry are reviewed, comparing different scenarios for the lightest
supersymmetric particle, which may or may not be stable. Possible scenarios for
R violation at HERA and future searches for supersymmetry at the LHC are also
mentioned briefly.


title: BFKL Scattering at LEPII and a Next e+ e- Collider

abstract:
  We discuss virtual photon scattering in the region dominated by BFKL exchange
and report results for the cross sections at present and future e+ e-
colliders.


title: Fritzsch-Xing mass matrices, $V_{td}$ and CP Violating phase $\delta$

abstract:
  Natural 4 zeros texture mass matrices recently proposed by Fritzsch and Xing
have been investigated by including `non-leading'corrections in the context of
latest data regarding m_t^{pole} and V_{CKM} matrix elements. Apart from
accommodating m_t^{pole} in the range 175\pm15 GeV, |V_{cb}| and
|V_{ub}/V_{cb}|=0.08\pm0.02, the analysis with maximal CP-violation predicts
|V_{td}| = .005-.013. Further, the CP-violating phase angle \delta can be
restricted to the ranges (i) 22^o -45^o and (ii) 95^o - 130^o, concretizing the
ambiguity regarding phase of CKM matrix. Furthermore, we find that non-leading
calculations are important when `Cabibbo triangle' is to be linked to unitarity
triangle.


title: Algorithm for the Fermionic Lines in GRACE-SUSY

abstract:
  Algorithm of constructing Feynman amplitudes in the framework of minimal
supersymmetic extension of the standard model is presented, which can be easily
implemented in GRACE, the program of automatic generation of Feynman
amplitudes. The equivalence of our method with the prescription given by Denner
et al. is proved.


title:
Generalized Vector Dominance and low x inelastic electron-proton
  scattering

abstract:
  The HERA data on inelastic lepton proton scattering for values of the Bjorken
scaling variable x < 0.05 are confronted with predictions based on Generalized
Vector Dominance. Good agreement between theory and experiment is found over
the full kinematic range of the squared four-momentum-transfer, Q^2, from Q^2 =
0 (photoproduction) to Q^2 < 350 GeV^2.


title: H-->ggg(gqqbar) at Two Loops in the Large-M_t Limit

abstract:
  We present a calculation of the two-loop helicity amplitudes for the
processes H-->ggg and H-->gqqbar in the large-M_t limit. In this limit the
calculation can be performed in terms of one-loop diagrams containing an
effective Hgg operator. These amplitudes are required for the next-to-leading
order (NLO) corrections to the Higgs transverse momentum distribution and the
next-to-next-to-leading order (NNLO) corrections to the Higgs production cross
section via the gluon fusion mechanism.


title: Inclusive $J/\psi$ photoproduction at HERA

abstract:
  I discuss the impact of color-octet contributions to inclusive $J/\psi$
photoproduction at HERA. Emphasis is put on resolved photon processes and on
$J/\psi$ polarization, which will be experimentally accessible at HERA in the
near future. Both analyses provide a powerful test of the NRQCD factorization
approach to charmonium production.


title: Gauge-Mediated Supersymmetry Breaking: Introduction, Review and Update

abstract:
  Recent progress in the gauge-mediated supersymmetry breaking is reviewed,
with emphasis on the theoretical problems which gauge-mediated models so
successfully solve, as well as those problems which are endemic to the models
themselves and still beguile theorists today.


title: Z' Physics and Supersymmetry

abstract:
  We review the status of heavy neutral gauge bosons, Z', with emphasis on
constraints that arise in supersymmetric models, especially those motivated
from superstring compactifications. We first summarize the current
phenomenological constraints and the prospects for Z' detection and diagnostics
at the LHC and NLC. After elaborating on the status and (lack of) predictive
power for general models with an additional Z', we concentrate on motivations
and successes for Z' physics in supersymmetric theories in general and in a
class of superstring models in particular. We review phenomenologically viable
scenarios with the Z' mass in the electroweak or in the intermediate scale
region.


title: The Significance of the Heavy Top Quark

abstract:
  Experiment shows that the top quark is far heavier than the other elementary
fermions. This finding has stimulated research on theories of electroweak and
flavor symmetry breaking that include physics beyond the standard model.
Efforts to accommodate a heavy top quark within existing frameworks have
revealed constraints on model-building. Other investigations have started from
the premise that a large top quark mass could signal a qualitative difference
between the top quark and other fermions, perhaps in the form of new
interactions peculiar to the top quark. Such new dynamics may also help answer
existing questions about electroweak and flavor physics. This talk explores the
implications of the heavy top quark in the context of weakly-coupled (e.g.
SUSY) and strongly-coupled (e.g. technicolor) theories of electroweak symmetry
breaking.


title: Constraint of the magnetic moment of the top quark

abstract:
  We derive a bound on the magnetic dipole moment of the top quark in the
context of the effective Lagrangian approach by using the values of the ratio
$R_b = \Gamma_b/\Gamma_h$, $R_l = \Gamma_h/\Gamma_l$ and $\Gamma_Z$. We found
that the oblique corrections are more sensible than the vertex ones for this
moment.


title:
Non-Decoupling Effects of Higgs Bosons on $e^+e^- \to W^+_LW^-_L$ in the
  Two-Doublet Model

abstract:
  The non-decoupling effects of heavy Higgs bosons on the process $e^+e^- \to
W^+_LW^-_L$ are discussed in the two Higgs-doublet model. The one-loop
corrections to the cross section are calculated by using the equivalence
theorem and the explicit expressions of its deviation from the standard model
are derived. The leading mass contributions to the deviation in expansion by
$s$ are related to the $T$ parameter by the low-energy theorem. The next-to
leading ones are free from the present data, which should be determined by
future experiments. The deviation can amount to $\sim 3$ % at $\sqrt{s} = 1$
TeV under the constraint from the present data, so that it may give useful
information on the Higgs sector in cooperation with data from future linear
colliders.


title: Statistical Matrix for Electroweak Baryogenesis

abstract:
  In electroweak baryogenesis, a domain wall between the spontaneously broken
and unbroken phases acts as a separator of baryon (or lepton) number,
generating a baryon asymmetry in the universe. If the wall is thin relative to
plasma mean free paths, one computes baryon current into the broken phase by
determining the quantum mechanical transmission of plasma components in the
potential of the spatially changing Higgs VEV. We show that baryon current can
also be obtained using a statistical density operator. This new formulation of
the problem provides a consistent framework for studying the influence of
quasiparticle lifetimes on baryon current. We show that when the plasma has no
self-interactions, familiar results are reproduced. When plasma
self-interactions are included, the baryon current into the broken phase is
related to an imaginary time temperature Green's function.


title: Hybrid Inflation and Particle Physics

abstract:
  The prototype hybrid SUSY SU(5) inflation models, while well motivated from
particle physics, and while allowing an acceptable inflationary phase with
little or no fine tuning, are shown to have two fundamental phenomenological
problems. (1) They inevitably result in the wrong vacuum after inflation is
over; and (2) they do not solve the monopole problem. In order to get around
the first problem the level of complexity of these models must be increased.
One can also avoid the second problem in this way. We also demonstate another
possibility by proposing a new general mechanism to avoid the monopole problem
with, or without inflation.


title: Solar neutrinos and grand unification

abstract:
  We consider the Grand Unification (GU) scenario for neutrino masses which is
based on the see-saw mechanism with the mass of the heaviest right handed (RH)
neutrino at the GU-scale: $M_3 \sim \Lambda_{GU}$, and on the quark-lepton
symmetry for fermions from the third generation. The scenario predicts for the
light neutrinos: $m_3 \sim (2 - 4) \cdot 10^{-3}$ eV and $m_2 \sim (0.3 - 3)
\cdot 10^{-5}$ eV (in the case of a linear mass hierarchy of the RH neutrinos
or/and in presence of the Planck scale suppressed non-renormalizable
operators). It also predicts large $\nu_e - \nu_{\mu}$ mixing: $~\sin^2
2\theta_{e\mu} \stackrel{_>}{_\sim} 0.2$. In this scenario the solar neutrinos
($\nu_{\odot}$) undergo both the \nue $\to$ \nutau resonance conversion in the
Sun and substantial \nue $\to$ \numu vacuum oscillations on the way from the
Sun to the Earth. The interplay of both effects enlarges the range of neutrino
parameters which solve the $\nu_{\odot}$-problem. In particular, $\nu_e -
\nu_{\tau}$ mixing angle can be as small as the corresponding quark mixing:
$\sin^2 2\theta_{e\tau} \geq (2~-~5) \cdot 10^{-4}$. The scenario predicts
peculiar (oscillatory) distortion of the boron neutrino energy spectrum and
seasonal variations of signals. Manifestations of these effects in the
Super-Kamiokande and SNO experiments are studied.