title:
Probing Planckian physics: resonant production of particles during
  inflation and features in the primordial power spectrum

abstract:
  The phenomenon of resonant production of particles {\it after} inflation has
received much attention in the past few years. In a new application of resonant
production of particles, we consider the effect of a resonance {\em during}
inflation. We show that if the inflaton is coupled to a massive particle,
resonant production of the particle during inflation modifies the evolution of
the inflaton, and may leave an imprint in the form of sharp features in the
primordial power spectrum. Precision measurements of microwave background
anisotropies and large-scale structure surveys could be sensitive to the
features, and probe the spectrum of particles as massive as the Planck scale.


title: Numerical analysis of the pi+pi- atom lifetime in ChPT

abstract:
  We apply Chiral Perturbation Theory at one loop to analyze the general
formula for the pi+pi- atom lifetime derived recently in the framework of QCD.
The corresponding analytic expression is investigated numerically, and compared
with recent work in the literature.


title:
Inclusive $\eta'$ production in B decays and the Enhancement due to
  charged technipions

abstract:
  The new contributions to the charmless B decay $B \to X_{s}\eta^{\prime}$
from the unit-charged technipions $P^{\pm}$ and $P^{\pm}_{8}$ are estimated.
The technipions can provide a large enhancement to the inclusive branching
ratio: $Br(B \to X_{s}\eta^{\prime}) \sim 7\times 10^{-4}$ for $m_{p1}=100GeV$
and $m_{p8}=250 \sim 350 GeV$ when the effect of QCD gluon anomaly is also
taken into account. The new physics effect is essential to interpret the CLEO
data.


title: Electromagnetic Signals of Hot Hadronic Matter

abstract:
  The photon and dilepton emission rates from quark gluon plasma and hot
hadronic matter have been evaluated. The in-medium modifications of the
particles appearing in the internal loop of the self energy diagram are taken
into account by using a phenomenological effective Lagrangian approach,
Brown-Rho and Nambu scaling scenarios. We note that the in-medium effects on
the low invariant mass distribution of dilepton and transverse momentum spectra
of photon are clearly visible.


title: Gravity, Parametric Resonance and Chaotic Inflation

abstract:
  We investigate the possibility that nonlinear gravitational effects influence
the preheating era after inflation. Our work is based on numerical solutions of
the inhomogeneous Einstein field equations, and is free of perturbative
approximations. The one restriction we impose is to limit the inhomogeneity to
a single spatial direction. We compare our results to perturbative calculations
and to solutions of the nonlinear field equations in a rigid (unperturbed)
spacetime, in order to isolate gravitational phenomena. We consider two types
of initial conditions: where only one mode of the field perturbation has a
non-zero initial amplitude, and where all the modes begin with a non-zero
amplitude. Here we focus on preheating following inflation driven by a scalar
field with a quartic potential. We confirm the broad picture of preheating
obtained from the nonlinear field equations in a rigid background, but
gravitational effects have a measurable impact on the dynamics for both sets of
initial data. The rigid spacetime results predict that the amplitude of a
single initially excited mode drops rapidly after resonance ends, whereas in
the relativistic case the amplitude is roughly constant. With all modes
initially excited, the longest modes in the simulation grow much more rapidly
in the relativistic calculation than with a rigid background. However, we see
no evidence for the sort of gravitational collapse associated with the
formation of primordial black holes. The numerical codes described here are
easily extended to more complicated resonant models, which we will examine in
the future.


title:
CP and T violation in (long)long baseline neutrino oscillation
  experiments

abstract:
  We consider possibilities of observing CP-violation effects in neutrino
oscillation experiments with low energy ($\sim$ several hundreds MeV).


title:
The light scalars and the broad sigma(500) in the U3xU3 linear sigma
  model

abstract:
  The lightest scalar and pseudoscalar nonets are discussed within the [A
framework of the broken old UxU3 linear sigma model, and it is shown that
already at the tree level this model works remarkably well predicting scalar
masses and couplings not far from present experimental values, when all
parameters are fixed from the pseudoscalar masses and decay constants. The
linear sigma model is the simplest way to implement chiral symmetry together
with the broken SU3 of the quark model, and this, not well known, success in
understanding experiment is comparable to that of the naive quark model for the
heavier multiplets. It is argued that this strongly suggest that the light and
very broad sigma resonance exists near 500 MeV.


title:
Neutrino oscillations in the early universe: How large lepton asymmetry
  can be generated?

abstract:
  The lepton asymmetry that could be generated in the early universe through
oscillations of active to sterile neutrinos is calculated (almost) analytically
for small mixing angles, sin 2\theta < 10^{-2}. It is shown that for a mass
squared difference, \delta m^2=-1 eV^2 it may rise at most by 6 orders of
magnitude from the initial ``normal'' value of 10^{-10}, since the
back-reaction from the refraction index terminates this rise while the
asymmetry is still small. Only for very large mass differences, \delta m^2
about 10^9 eV^2, the lepton asymmetry could reach a significant magnitude
exceeding 0.1.


title: One-Loop Radiative Corrections to Chargino Pair Production

abstract:
  We report on the effect that one-loop radiative corrections to the chargino
pair production cross section has on the determination of the fundamental
parameters of the theory. We work in the context of electron-positron colliders
with sqrt(s)=500 GeV. We conclude that the inclusion of these corrections is
crucial in precision measurements, specially at large and small values of
tan(beta).


title: Flow Equations and the Chiral Phase Transition

abstract:
  Flow equations for an O(N)-symmetric effective potential are discussed and
solved for the finite temperature case. The model is investigated at the
critical point and critical exponents for various N are calculated.


title: Neutrino Masses in SO(10) Theories

abstract:
  We review the status of a class of gauge unified models based on SO(10) group
and discuss the main phenomenological implications of these models in
particular for neutrino masses.


title:
Comparison of Next-to-Leading Order Calculations for Jet Cross Sections
  in Deep-Inelastic Scattering

abstract:
  We compare different next-to-leading order calculations of jet cross sections
in deep-inelastic scattering as implemented in the programs DISASTER++, DISENT,
JETVIP and MEPJET. In all phase space regions under study DISENT and DISASTER++
agree better than 2%. MEPJET shows systematic deviations of being typically
5-8% lower than the other programs. The JETVIP results show a significant
dependence on the phase space slicing parameter $y_{\rm cut}$. In the cases
where the $y_{\rm cut}$ dependence within $10^{-4} \le y_{\rm cut} \le 10^{-3}$
is smaller than 3% the JETVIP results are often comparable with the DISENT and
DISASTER++ results.


title: Higgs Particles at Linear e+e- Colliders: theoretical issues

abstract:
  I summarize the prospects for discovering and studying the properties of
Higgs particles at future high-energy and high-luminosity $e^+e^-$ linear
colliders. I will focus on the Higgs particle of the Standard Model and the
Higgs bosons predicted by Supersymmetric theories.


title: BFT Hamiltonian embedding for SU(3) Skyrmion

abstract:
  We newly apply the Batalin, Fradkin and Tyutin (BFT) formalism to the SU(3)
flavor Skyrmion model to investigate the Weyl ordering correction to the
structure of the hyperfine splittings of strange baryons. On the other hand,
the Berry phases and Casimir effects are also discussed.


title: Consistent HTL resummation of the thermodynamical potential

abstract:
  The thermodynamical potential of relativistic gauge theories can be
consistently resummed in terms of HTL propagators, which is, without being
restricted to it, exemplified for the case of hot QED. The nonperturbative
resummation is gauge independent, free of thermal divergences and, in the
weak-coupling limit, compatible with the leading order perturbative result.


title:
Symmetry limit properties of a priori mixing amplitudes for non-leptonic
  and weak radiative decays of hyperons

abstract:
  We show that the so-called parity-conserving amplitudes predicted in the a
priori mixing scheme for non-leptonic and weak radiative decays of hyperons
vanish in the strong-flavor symmetry limit.


title: Dynamical lattice QCD thermodynamics with domain wall fermions

abstract:
  We present results from simulations of two flavor QCD thermodynamics at N_t=4
with domain wall fermions. In contrast to other lattice fermion formulations,
domain wall fermions preserve the full chiral symmetry of the continuum at
finite lattice spacing (up to terms exponentially small in an extra parameter).
Just above the phase transition, we find that the axial U(1) symmetry is broken
only by a small amount. We discuss an ongoing calculation to determine the
order and properties of the phase transition using domain wall fermions, since
the global symmetries of the theory are expected to be important here.


title: A priori mixing of mesons and the |Delta I|=1/2 rule in K\to\pi\pi

abstract:
  We consider the hypothesis of a priori mixings in the mass eigenstates of
mesons to obtain the |Delta I|=1/2 rule in K\to\pi\pi. The Hamiltonian
responsible for the transition is the strong interacting one. The experimental
data are described using the isospin symmetry relations between the strong
coupling constants.


title: Isospin Violation and the Proton's Strange Form Factors

abstract:
  The strange form factors of the proton are basic to an understanding of
proton structure, and are presently the focus of many experiments. Before the
strangeness effects can be extracted from data, it is necessary to calculate
and remove effects due to isospin violation, which exist independently of the
strange quark but which contribute nevertheless to the experimentally measured
``strange'' form factors. A discussion of the isospin violating contributions
to vector form factors is given here in the context of heavy baryon chiral
perturbation theory.


title: Kaluza-Klein Excitations and Electroweak Symmetry Breaking

abstract:
  We explore the possibility that the Kaluza-Klein graviton states induce
electroweak symmetry breaking. We also demonstrate that electroweak symmetry
breaking could have a large impact on KK phenomenology.


title: Indirect Search for Supersymmetry

abstract:
  Effects of supersymmetric particles may appear in various low energy
experiments through loop diagrams. We discuss various flavor changing neutral
current processes, the muon anomalous magnetic moment and lepton flavor
violation in the context of the supergravity model. In particular the
$B^0$-$\ol{B}^0$ mixing and the muon anomalous magnetic moment are revisited
taking into account the recent Higgs boson search result. We also consider
$\mu^+ \to e^+ \gamma$ and $\mu^+ \to e^+ e^+ e^-$ processes with polarized
muons. We calculate the P-odd and T-odd asymmetries in these processes for
SU(5) and SO(10) supersymmetric grand unified theories and show that these
asymmetries are useful to distinguish different models.


title: The Triangle Anomaly in Triple-Regge Limits

abstract:
  Reggeized gluon interactions due to a single quark loop are studied in the
full triple-regge limit and in closely related helicity-flip helicity-pole
limits. Triangle diagram reggeon interactions are generated that include local
axial-vector effective vertices. It is shown that the massless quark triangle
anomaly is present as a chirality-violating infra-red divergence in the
interactions generated by maximally non-planar Feynman diagrams. An asymptotic
dispersion relation formalism is developed which provides a systematic counting
of anomaly contributions. The asymptotic amplitude is written as a sum over
dispersion integrals of triple discontinuities, one set of which is unphysical
and can produce chirality transitions. The physical-region anomaly appears in
the generalized real parts, determined by multi-regge theory, of the unphysical
discontinuities. The amplitudes satisfy a signature conservation rule that
implies color parity is not conserved by vertices containing the anomaly. In
the scattering of elementary quarks or gluons the signature and color parity of
the exchanged reggeon states are such that the anomaly cancels. At
lowest-order, it cancels in individual diagrams after the transverse momentum
integrations are performed.


title: The Triple-Regge Triangle Anomaly

abstract:
  It is shown that the triangle anomaly is present, as an infra-red divergence,
in the six-reggeon triple-regge interaction vertex obtained from a maximally
non-planar Feynman diagram in the full triple-regge limit of three-to-three
quark scattering. A multi-regge asymptotic dispersion relation formalism can be
used to isolate all anomaly contributions and to discuss when and how there is
a cancelation.


title: Radiative corrections to deeply virtual Compton scattering

abstract:
  We discuss possibilities of measurement of deeply virtual Compton scattering
amplitudes via different asymmetries in order to access the underlying skewed
parton distributions. Perturbative one-loop coefficient functions and two-loop
evolution kernels, calculated recently by a tentative use of residual conformal
symmetry of QCD, are used for a model dependent numerical estimation of
scattering amplitudes.


title:
Spontaneous Violation of the CP Symmetry in the Higgs Sector of the
  Next-to-Minimal Supersymmetric Model

abstract:
  The spontaneous violation of the CP symmetry in the next-to-minimal
supersymmetric standard Model (NMSSM) is investigated. It is found that the
spontaneous violation of the CP symmetry can occur in the Higgs sector of the
NMSSM for a wide region of the parameter space of the model, at the 1-loop
level where the radiative corrections due to the top quark and scalar-top quark
loops are found to generate the scalar-pseudoscalar mixings between the two
Higgs doublets of the NMSSM. In our model, we assume that the masses of the
left-handed and the right-handed scalar-top quarks are not degenerate. And we
investigate our model anaytically: We derive analytical formulae of the 1-loop
mass matrix for the neutral Higgs bosons. We calculate the upper bound on the
lightest neutral Higgs boson mass under the assumption. It is found to be about
140 GeV for our choice of parameter values in the presence of the spontaneous
violation of the CP symmetry in the NMSSM. Thus, the possibility of the
spontaneous violation of the CP symmetry is not completely ruled out in the
Higgs sector of the NMSSM if the masses of the left-handed and the right-handed
scalar-top quarks are not degenerate. Further, the phenomenology of the
$K$-${\bar K}$ mixing within the context of our model is studied. The lower
bound on CP violating phase in the $K$-${\bar K}$ mixing is found to increase
if either $\tan\beta$ decreases or $A_t$ increases.


title:
On the scaling behavior of the cosmological constant and the possible
  existence of new forces and new light degrees of freedom

abstract:
  A large value of the cosmological constant (CC) is induced in the Standard
Model (SM) of Elementary Particle Physics because of Spontaneous Symmetry
Breaking. To provide a small value of the observable CC one has to introduce
the vacuum term which cancels the induced one at some point in the very far
infrared cosmic scale. Starting from this point we investigate whether the
cancellation is preserved at different energy scales. We find that the running
of the Higgs mass, couplings and the vacuum term inevitably result in a scaling
dependence of the observable CC value. As a consequence one meets a nonzero CC
at an energy scale comparable to the typical electron neutrino mass suggested
by some experiments, and the order of magnitude of this constant is roughly the
one derived from recent supernovae observations. However the sign of it is
negative -- opposite to what is suggested by these observations. This
discrepancy may be a hint of the existence of an extra very light scalar,
perhaps a Cosmon-like dilaton, which should essentially decouple from the SM
Lagrangian, but that it nevertheless could mediate new macroscopic forces in
the submillimeter range.


title: Production of four jets in LR model

abstract:
  We consider the reaction ee -> q,q,qbar,qbar as a test of lepton number
non-conservation in the framework of the left-right-symmetric electroweak
model. The main contributions to this process are due to Majorana neutrino
exchange in t-channel and doubly charged Higgs (Delta(--)) exchange in
s-channel with a pair of right-handed weak bosons (WR) as intermediate state.
We show that in a linear ee collider with the collision energy of 1 TeV (1.5
TeV) the cross section of this process is 0.01 fb (1 fb), and it will, for the
anticipated luminosity of 10**35 cm**(-2)s**(-1), be detectable below the WR
threshold. We study the sensitivity of the reaction on the masses of the heavy
neutrino, WR and Delta(--).


title: Polarized antiquark flavor asymmetry in Drell-Yan pair production

abstract:
  We investigate the role of the flavor asymmetry of the nucleon's polarized
antiquark distributions in Drell-Yan lepton pair production in polarized
nucleon-nucleon collisions at HERA (fixed-target) and RHIC energies. It is
shown that the large polarized antiquark flavor asymmetry predicted by model
calculations in the large-N_c limit (chiral quark-soliton model) has a dramatic
effect on the double spin asymmetries in high mass lepton pair production, as
well as on the single spin asymmetries in lepton pair production through
$W^\pm$-bosons at $M^2 = M_W^2$.


title:
Additional two-loop contributions to electric dipole moments in
  supersymmetric theories

abstract:
  We calculate the two-loop contributions to the electric dipole moments of the
electron and the neutron mediated by charged Higgs in a generic supersymmetric
theories. The new contributions are originated from the potential CP violation
in the trilinear couplings of the charged Higgs bosons to the scalar-top or the
scalar-bottom quarks. These couplings did not receive stringent constraints
directly. We find observable effects for a sizeable portion of the parameter
space related to the third generation scalar-quarks in the minimal
supersymmetric standard model.


title:
Spin configuration of top quark pair production with large extra
  dimensions at photon-photon colliders

abstract:
  Top quark pair production at photon-photon colliders is studied in low scale
quantum gravity scenario. From the dependence of the cross sections on the spin
configuration of the top quark and anti-quark, we introduce a new observable,
top spin asymmetry. It is shown that there exists a special top spin basis
where with the polarized parent electron beams the top spin asymmetry vanishes
in the standard model but retains substantial values with the large extra
dimension effects. We also present lower bounds of the quantum gravity scale
$M_S$ from total cross sections with various combinations of the laser,
electron beam, and top quark pair polarizations. The measurements of the top
spin state $(t_\uparrow\bar{t}_\downarrow)$ with unpolarized initial beams are
shown to be most effective, enhancing by about 5% the $M_S$ bounds with respect
to totally unpolarized case.


title: The inclusive B->eta' X_s decay and b-> sg* form factors

abstract:
  We compute the branching ratio of inclusive $B \to \eta' X_s$ decay based
upon the QCD anomaly mechanism: $b\to s+g^*\to s+g+\eta'$. To obtain a reliable
$B \to \eta' X_s$ branching ratio, we calculate the $b\to s+g^*$ form factors
up to the next-to-leading-logarithmic(NLL) approximation. We point out that the
Standard Model prediction for $B\to \eta' X_s$ is consistent with the CLEO
data, in contrast to the claims of some previous works.


title: The November $J/\Psi$ Revolution: Twenty-Five Years Later

abstract:
  Exactly twenty five years ago the world of high energy physics was set on
fire by the discovery of a new particle with an unusually narrow width at 3095
MeV, known popularly as the $J/\Psi$ revolution. This discovery was very
decisive in our understanding as well as formulating the current picture
regarding the basic constituents of nature. I look back at the discovery,
pointing out how unexpected, dramatic and significant it was.

categories: hep-ph hep-ex hep-lat hep-th physics.hist-ph


title:
Electromagnetic transitions of excited baryons in a deformed oscillator
  quark model

abstract:
  We study electromagnetic transitions of excited baryons in a deformed
oscillator quark model, where baryon excited states are described as rotational
bands of deformed intrinsic states. We describe all necessary tools to compute
transition amplitudes in multipole basis, which are then related to the
commonly used helicity amplitudes. We pay a special attention on the sign of
the amplitudes as well as their absolute values by computing the photon and
pion couplings simultaneously. We have found that the effect of deformation on
the transition amplitudes is rather weak. The difficulty in reproducing the
empirical amplitude of the Roper state is discussed.


title: Ferromagnetism of quark liquid

abstract:
  Usually it is believed that the Hartree-Fock state of quark matter is a Fermi
gas state with no polarisation of spins. We examine the possibility of the
polarised quark liquid interacting with the one-gluon-exchange interaction. It
is suggested that the Hartree-Fock state shows a spontaneous magnetic
instability at low densities through the same mechanism as the appearance of
ferromagnetism in electron gas. Metastability of the polarised quark liquid is
also discussed.


title: Will relativistic heavy-ion colliders destroy our planet?

abstract:
  Experiments at the Brookhaven National Laboratory will study collisions
between gold nuclei at unprecedented energies. The concern has been voiced that
``strangelets''-hypothetical products of these collisions - may trigger the
destruction of our planet. We show how naturally occurring heavy-ion collisions
can be used to derive a safe and stringent upper bound on the risk incurred in
running these experiments.


title: The Minimal Extension of the SM and the Neutrino Oscillation Data

abstract:
  We study the simplest Standard Model estension with only one extra
right-handed neutrino. In this case there are two massless $m_{1,2}$ and two
massive $m_{3,4}$ neutrinos, and in principle both solar and atmospheric
anomalies can be described in two different scenarios, $m_3 << m_4$ (scheme I)
and $m_3 \simeq m_4$ (scheme II). However, neither bi-maximal mixing nor the
dark matter problem are explained in this minimal extension. Only scheme II can
accommodate simultaneously maximal mixing for atmospheric neutrinos and the
small mixing angle MSW solution for the solar anomaly. This scenario can be
tested in the BOREXINO experiment.


title: Macroscopic Forces driven by Resonant Neutrino Conversion

abstract:
  We show that neutrino oscillations in matter are always accompanied by
collective forces on the medium. This effect may produce interesting
consequences for the background and the neutrino oscillations themselves. The
force is maximal in the case of resonant neutrino conversion in the adiabatic
regime. We study here the forces driven by $\nu_e-\nu_{\mu,\tau}$ and
$\nu_e-\nu_s$ MSW conversion and shortly discuss their possible relevance for
the dynamics of a type II supernova.


title: Sterile Neutrino as a Bulk Neutrino

abstract:
  If light sterile neutrinos are needed to understand the neutrino puzzles, as
is currently indicated, a major theoretical challenge is to understand why its
mass is so small. It is a more serious problem than understanding the small
mass of the familiar neutrinos. We discuss a new way to solve this problem by
identifying the sterile neutrino as gauge neutral fermion propagating in the
bulk of a higher dimensional theory, with bulk size of order of a millimeter.
The smallness of its mass is then a consequence of the size of the extra
dimension and does not need the introduction of new symmetries. We present a
realistic model for neutrino masses and mixings that implements this idea.


title:
Radiative corrections to the structure functions and sum rules in
  polarized DIS

abstract:
  The one-loop NLO radiative corrections to the observables in polarized DIS
using assumption that a quark is an essential massive particle are considered.
If compared with classical QCD formulae the obtained results are identical for
the unpolarized and different for polarized sum rules, that can be explained as
the influence of the finite quark mass effects on NLO QCD corrections. The
explicit expression for one-loop NLO QCD contribution to the structure function
g_2 is presented.


title: Neutrino Oscillations in Electromagnetic Fields

abstract:
  Oscillations of neutrinos $\nu_L \leftrightarrow \nu_R$ in presence of an
arbitrary electromagnetic field are considered. We introduce the Hamiltonian
for the neutrino spin evolution equation that accounts for possible effects of
interaction of neutrino magnetic $\mu$ and electric $\epsilon$ dipole moments
with the transversal (in respect to the neutrino momentum) and also the
longitudinal components of electromagnetic field. Using this Hamiltonian we
predict the new types of resonances in the neutrino oscillations $\nu_L
\leftrightarrow \nu_R$ in the presence of the field of an electromagnetic wave
and in combination of an electromagnetic wave and constant magnetic field. The
possible influence of the longitudinal magnetic field on neutrino oscillations
is emphasized.


title: Measuring Gaugino Soft Phases and the LSP Mass At Fermilab

abstract:
  Once superpartners are discovered at colliders, the next challenge will be to
determine the parameters of the supersymmetric Lagrangian. We illustrate how
the relative phases of the gluino, SU(2), and U(1) gauginos and the Higgsino
mass parameter mu can be measured at a hadron collider without ad hoc
assumptions about the underlying physics, focusing on Fermilab. We also discuss
how the gluino and LSP masses can be measured.


title:
Comment on ``Inflation and flat directions in modular invariant
  superstring effective theories''

abstract:
  The inflation model of Gaillard, Lyth and Murayama is revisited, with a
systematic scan of the parameter space for dilaton stabilization during
inflation.


title: Non-local regularization of chiral quark models in the soliton sector

abstract:
  A chiral quark model is described which is regularized in terms of Lorentz
invariant non-local interactions. The model is regularized to all loop orders
and it ensures the proper quantization of the baryon number. It sustains bound
hedgehog solitons which, after suitable centre of mass corrections, can
adequately describe the nucleon.


title: Non-factorizable contribution in B decays

abstract:
  Two body decays of B mesons are studied by decomposing their amplitude into a
sum of factorizable and non-factorizable ones. The former is estimated by using
a naive factorization while the latter is assumed to be dominated by dynamical
contributions of various hadron states and is calculated by using a hard pion
(or kaon) technique in the infinite momentum frame. Possible roles of the
non-factorizable contributions are discussed by comparing the result with
experiments.


title: Higgs Sector in Anomaly-Mediated Supersymmetry Breaking Scenario

abstract:
  In the minimal anomaly-mediated supersymmetry breaking (AMSB) model, a
universal contribution $m_{0}$ to all the scalar masses is introduced in order
to avoid the negative slepton mass problem. The Higgs spectrum and couplings
are determined by four parameters: $m_{\rm aux}, m_{0}, \tan\beta$ and sign
($\mu$). The sign of $\mu$ affects $m_A$ at large $\tan\beta$ and $m_h$ at
small $\tan\beta$. The CP-odd Higgs mass $m_A$ is usually much larger than
${m}_{Z}$ and the lightest CP-even Higgs is simply analogous to the one in the
standard model. The current and future Higgs searches in LEP, Tevatron and LHC
provide a test ground for the AMSB scenario. The current LEP bounds and LEP
192/196 preliminary results have already excluded a small $m_{0}$ and $m_{\rm
aux}$ region for small $\tan\beta$. While the entire parameter space will be
excluded if no Higgs is found at Tevatron RUN II with 2 ${\rm fb}^{-1}$
luminosity. However, if the AMSB scenario is true, a Higgs can be found at
5$\sigma$ significance level at both Tevatron running at luminosity 10 ${\rm
fb}^{-1}$ or higher and LHC.


title: R-parity Violating Radiative Photino Decay in Supersymmetric Models

abstract:
  It has been shown that unless the tri-linear R-parity violating coupling
$\lambda_{i33}$ (i = 1, 2) is small enough ($\lambda_{i33}<$ ${10}^{-2}$ for
MSSM and ${10}^{-3}$ for GMSB model),the partial decay width of photino
decaying into 'photon + $\nu_{e,\mu}$', both in supergravity motivated (MSSM)
and gauge mediated (GMSB) supersymmetric models are larger than the partial
decay width of photino decaying into 'photon + goldstino' in R-parity
conserving GMSB model including one loop supersymmetric QED correction.


title: Single top production at the LHC as a probe of R parity violation

abstract:
  We investigate the potential of the LHC to probe the R parity violating
couplings involving the third generation by considering single top production.
This study is based on particle level event generation for both signal and
background, interfaced to a simplified simulation of the ATLAS detector.


title: Proton-proton total cross sections estimations at very high energies

abstract:
  Proton-proton total cross sections are measured with present day high energy
colliders up to 2 TeV in the centre-of-mass of the system (10^{15}) eV in the
laboratory). Several parameterizations, very succesful at low energies, can
then be used to extrapolate the measured values and get estimations of cross
sections to higher energies (10^{17} eV). On the other hand, from very high
energetic cosmic rays (> 10^{17} eV) and using some approximations, it is
possible to get a value for proton-proton total cross section from the
knowledge of the proton-proton total cross section at these energies. Here we
use a phenomenological model to estimate proton-proton total cross section at
cosmic ray energies. On the basis of regression analysis we show that the
predictions are highly sensitive to the employed data for extrapolation. Using
data at 1.8 TeV our extrapolations for proton-proton total cross section are
incompatible with most of cosmic ray results


title: Polarized parton distributions in perturbative QCD

abstract:
  We review the main results of next-to-leading order QCD analyses of polarized
deep-inelastic scattering data, with special attention to the assessment of
theoretical uncertainties.


title: Prospects on Compositeness and New Vector Bosons at LC with Polarization

abstract:
  Fermion compositness, and other new physics which can be described by an
exchange of very massive particles ($Z^\prime$ boson, leptoquarks, sparticles
with R-parity violating couplings), can be manifest itself as the presence of a
strong four-fermion contact interaction. For the processes $e^+e^-\to
\mu^+\mu^-$, $\tau^+\tau^-$, $\bar{b}b$ and $\bar{c}c$ at a future $e^+e^-$
linear collider (LC) with $\sqrt{s}=0.5$ TeV, we examine the sensitivity of the
helicity cross sections to four-fermion contact interactions. If longitudinal
polarization of the electron beam were available, two polarized integrated
cross sections would offer the opportunity to separate the helicity cross
sections and, in this way, to derive model-independent bounds on the relevant
parameters. The measurement of these polarized cross sections with optimal
kinematical cuts could significantly increase the sensitivity of helicity cross
sections to contact interaction parameters and could give crucial information
on the chiral structure of such new interactions. In addition, we consider the
application of the proposed approach to the search for manifestations of a
$Z^\prime$ for typical extended model examples.


title: Integrability of twist - 3 evolution equations in QCD

abstract:
  The recent progress in solution of the evolution equations of three particle
hadron distribution amplitudes is reviewed.


title: alpha^2 corrections to parapositronium decay: a detailed description

abstract:
  We present details of our recent calculation of alpha^2 corrections to the
parapositronium decay into two photons. These corrections are rather small and
our final result for the parapositronium lifetime agrees well with the most
recent measurement. Implications for orthopositronium decays are briefly
discussed.


title: On coherent particle production in central 4.3 A Gev/c Mg-Mg collisions

abstract:
  Features of dense groups, or spikes, of negative pions produced in Mg-Mg
collisions at 4.3 GeV/c/nucleon are studied to search for a coherent,
Cerenkov-like, mechanism of particle production process. We investigate the
distributions of spike centers and, for the first time, the energy spectra of
particles in spikes. The spike-center distributions are obtained to exhibit the
structure due to the coherent gluon-jet emission dynamics. This structure is
similar to that observed recently for all-charged-particle spikes in hadronic
and nuclear interactions. The energy distribution within spikes is found to
have a significant peak over the inclusive background, while the inclusive
spectrum shows exponential decrease with two characteristic values of average
kinetic energy. The value of the peak energy and its width are in a good
agreement with those expected for pions produced in a nuclear medium in the
framework of the Cerenkov quantum approach. The peak energy obtained is
consistent with the value of the cross-section maximum observed in coincidence
experiments of nucleon-nucleus interactions.


title:
Value of $\alpha_s$ and high twists from combined analysis $e-\mu$ DIS
  data

abstract:
  We perform a NLO QCD analysis of the combined SLAC-BCDMS-NMC-E665-H1-ZEUS
data on inclusive deep inelastic cross section. Particular attention was paid
to the extraction of strong coupling constant $\alpha_s$ and high twist (HT)
contribution to the structure functions $F_2$ and $F_L$. It was shown that at
small and moderate x there is a visible dependence of the extracted values of
HT contribution to $F_2$ on the QCD renormalization scale, which indicates that
in this region extracted HT can absorb NNLO QCD corrections. At larger x the
dependence of HT on the renormalization scale is negligible and the influence
of NNLO correction on their values should be less significant. The value of
$\alpha_s(M_Z)=0.1159\pm0.0031$ (total) is obtained, where the error includes
statistical, systematical and theoretical uncertainties.


title:
Inverse meson mass ordering in color-flavor-locking phase of high
  density QCD

abstract:
  We derive the effective Lagrangian for the low-energy massive meson
excitations of the color-flavor-locking (CFL) phase of QCD with 3 flavors of
light quarks. We compute the decay constants, the maximum velocities, and the
masses of the mesons at large baryon chemical potential mu. The decay constants
are linear in mu. The meson maximum velocities are close to that of sound. The
meson masses in the CFL phase are significantly smaller than in the normal QCD
vacuum and depend only on bare quark masses. The order of the meson masses is,
to some extent, reversed compared to that in the QCD vacuum. In particular, the
lightest particle is eta'.


title: An introduction to leading and next-to-leading BFKL

abstract:
  Of late, the field of BFKL physics has been the subject of significant
developments. The calculation of the NLL terms was recently completed, and they
turned out to be very large. Techniques have been proposed to resum these
corrections. These lectures provide an introduction to the BFKL equation and
some of the recent developments, using DGLAP evolution as the starting point.


title: Gauge Unification within the Dual Standard Model

abstract:
  We calculate the gauge couplings in the dual standard model. These values are
consistent with an associated GeV mass scale, and predict the weak mixing angle
to be ${\sin^2 \theta_w} (M_Z) \sim 0.22$.


title: Solutions to the Atmospheric Neutrino Problem

abstract:
  In this talk I review the present status of the atmospheric neutrino anomaly
and discuss some solutions that have been presented in the literature to solve
this problem. In particular I review the "standard" solution in terms of
neutrino oscillations as well as alternative scenarios such as the possibility
of flavour changing neutrino interactions with the Earth and neutrino decay.


title: Strong interactions of weak bosons

abstract:
  We discuss the parameterization for electroweak gauge boson interactions
without a light Higgs boson. We present the constraints on the anomalous
gauge-boson couplings from the current experiments. We emphasize that the
four-point couplings involving the longitudinal weak bosons are genuine to the
underlying strong dynamics responsible for the electroweak symmetry breaking.
We study the sensitivity to the four-point couplings and the possible heavy
resonant states in this sector at future TeV $e^+e^-$ linear colliders.


title: Asymptotic Expansions - Methods and Applications

abstract:
  Different viewpoints on the asymptotic expansion of Feynman diagrams are
reviewed. The relations between the field theoretic and diagrammatic approaches
are sketched. The focus is on problems with large masses or large external
momenta. Several recent applications also for other limiting cases are touched
upon. Finally, the pros and cons of the different approaches are briefly
discussed.


title: Can multi-TeV (top and other) squarks be natural in gauge mediation?

abstract:
  We investigate whether multi-TeV (1-3 TeV) squarks can be natural in models
of gauge mediated SUSY breaking. The idea is that for some boundary condition
of the scalar (Higgs and stop) masses, the Higgs (mass)$^2$, evaluated at the
renormalization scale $\sim O(100)$ GeV, is not very sensitive to (boundary
values of) the scalar masses (this has been called ``focussing'' in recent
literature). Then, the stop masses can be multi-TeV without leading to
fine-tuning in electroweak symmetry breaking. {\em Minimal} gauge mediation
does {\em not} lead to this focussing (for all values of $\tan \beta$ and the
messenger scale): the (boundary value of) the Higgs mass is too small compared
to the stop masses. Also, in minimal gauge mediation, the gaugino masses are of
the same order as the scalar masses so that multi-TeV scalars implies multi-TeV
gauginos (especially gluino) leading to fine-tuning. We discuss ideas to {\em
increase} the Higgs mass relative to the stop masses (so that focussing can be
achieved) and also to {\em suppress} gaugino masses relative to scalar masses
(or to modify the gaugino mass relations) in {\em non-minimal} models of gauge
mediation -- then multi-TeV (top and other) squarks can be natural. Specific
models of gauge mediation which incorporate these ideas and thus have squarks
(and in some cases, the gluino) heavier than a TeV without resulting in
fine-tuning are also studied and their collider signals are contrasted with
those of other models which have multi-TeV squarks.


title: Cosmological Expansion in the Randall-Sundrum Brane World Scenario

abstract:
  The cosmology of the Randall-Sundrum scenario for a positive tension brane in
a 5-D Universe with localized gravity has been studied previously. In the
radiation-dominated Universe, it was suggested that there are two solutions for
the cosmic scale factor a(t) : the standard solution $a\sim t^{1/2}$, and a
solution $a\sim t^{1/4}$, which is incompatible with standard big bang
nucleosynthesis. In this note, we reconsider expansion of the Universe in this
scenario. We derive and solve a first order, linear differential equation for
H^2, the square of the expansion rate of the Universe, as a function of a. The
differences between our equation for H^2 and the relationship found in standard
cosmology are (i) there is a term proportional to density squared (a fact
already known), which is small when the density is small compared to the brane
tension, and (ii) there is a contribution which acts like a relativistic fluid.
We show that this second contribution is due to gravitational degrees of
freedom in the bulk. Thus, we find that there need not be any conflict between
cosmology of the Randall-Sundrum scenario and the standard model of cosmology.
We discuss how reheating at the end of inflation leads to the correct
relationship between matter density and expansion rate, $H^2\to 8\pi
G\rho_m/3$, and the conditions that must be met for the expansion rate of the
Universe to be close to its standard model value around the epoch of
cosmological nucleosynthesis.


title: Dynamics and perturbations in assisted chaotic inflation

abstract:
  On compactification from higher dimensions, a single free massive scalar
field gives rise to a set of effective four-dimensional scalar fields, each
with a different mass. These can cooperate to drive a period of inflation known
as assisted inflation. We analyze the dynamics of the simplest implementation
of this idea, paying particular attention to the decoupling of fields from the
slow-roll regime as inflation proceeds. Unlike normal models of inflation, the
dynamics does not become independent of the initial conditions at late times.
In particular, we estimate the density perturbations obtained, which retain a
memory of the initial conditions even though a homogeneous, spatially-flat
Universe is generated.


title: Physics Potential of a Tevatron Tripler

abstract:
  We explore the capabilities for new physics discovery in proton-antiproton
collisions at 5.4 TeV center-of-mass energy with luminosity $10^{33} cm^{-2}
s^{-1}$ at a Tripler upgrade of the Tevatron collider. The prospects are robust
for the usual Higgs boson and supersymmetry benchmarks. With an integrated
luminosity of 40 fb$^{-1}$, discoveries at 5$\sigma$ could be made for a
standard Higgs boson of mass $\alt 680$ GeV (600 GeV for 10 fb$^{-1}$), a
lighter chargino of mass $\alt 380$ GeV, and an extra $Z$ boson of mass $\alt
2.6$ TeV; four-fermion contact interactions from new physics with scale $\alt
74$ TeV could be excluded at the 95% confidence level.


title: A Systematic Analysis of the Exclusive B -> K^* l^+ l^- Decay

abstract:
  A model-independent analysis for the exclusive, rare B -> K^* l^+ l^- decay
is presented. Systematically studied are the experimentally measured
quantities, such as, branching ratio, forward-backward asymmetry, longitudinal
polarization of the final leptons, and the ratio $\Gamma_L/\Gamma_T$ of the
decay widths when $K^\ast$ meson is longitudinally and transversally polarized.
The dependence of the asymmetry parameter $\alpha = 2 \Gamma_L/\Gamma_T -1$ on
the new Wilson coefficients is also studied in detail. It is found that the
afore-mentioned physical observables are quite sensitive to the new Wilson
coefficients. Therefore, once we have the experimental data with high
statistics and a deviation from the Standard Model, we can interpret the source
of such discrepancy.


title:
Nonperturbative evaluation of the few-body states for scalar
  $\chi^2\phi$ interaction

abstract:
  A knowledge of nonpertubative propagators is often needed when the standard
perturbative methods are not applicable. An example of this is the bound state
problem in field theory. While a nonperturbative result is valuable by itself,
it is also an important guide for those who work on developing phenomenological
models for the nonperturbative problem. The Feynman-Schwinger representation
approach provides a convenient framework for calculating nonperturbative
propagators. In this paper we provide an algorithm for computing 1,2, and 3
body bound states with the inclusion of all self energies, vertex corrections,
ladder and crossed ladder exchanges. The calculation is done in the quenched
approximation by ignoring the matter loops. We provide simulation results for
1,2 and 3-body states.


title: Hadron Structure Functions in a Chiral Quark Model

abstract:
  We present a consistent regularization procedure for calculating hadron
structure functions in a bosonized chiral quark model. We find that the
Pauli-Villars regularization scheme is most suitable. We also summarize the
phenomenology of structure functions calculated in the valence quark
approximation.


title:
The lightest neutral and doubly charged Higgs bosons of supersymmetric
  left-right models

abstract:
  We review the phenomenology of light Higgs scalars in supersymmetric
left-right models. We consider models with minimal particle content (with and
without non-renormalizable higher-dimensional terms) and with additional Higgs
superfields. The upper bound on the lightest CP-even neutral Higgs boson in
these models is larger than in the minimal supersymmetric standard model, and
the Higgs couplings to fermions approach those of the Standard Model. Possibly
light doubly charged Higgs boson may provide the best signature of these
models.


title: QCD factorization for exclusive, non-leptonic B decays

abstract:
  Exclusive, non-leptonic, two-body decays of B mesons simplify greatly in the
heavy quark limit. In this talk I discuss the factorized structure that holds
in this limit and some of its consequences: (a) naive factorization is
recovered in a certain limit; (b) `non-factorizable' effects are hard and can
be calculated; (c) strong interaction phases vanish in the heavy quark limit
(and can be calculated as well). As an illustration, I compute the penguin
contribution to the decay $B_d\to\pi^+\pi^-$ and its effect on the
determination of $\sin 2\alpha$.


title: Fine-Tuning Constraints on Supergravity Models

abstract:
  We discuss fine-tuning constraints on supergravity models. The tightest
constraints come from the experimental mass limits on two key particles: the
lightest CP even Higgs boson and the gluino. We also include the lightest
chargino which is relevant when universal gaugino masses are assumed. For each
of these particles we show how fine-tuning increases with the experimental mass
limit, for four types of supergravity model: minimal supergravity, no-scale
supergravity (relaxing the universal gaugino mass assumption), D-brane models
and anomaly mediated supersymmetry breaking models. Among these models, the
D-brane model is less fine tuned.The experimental propects for an early
discovery of Higgs and supersymmetry at LEP and the Tevatron are discussed in
this framework.


title:
Polarization to Probe an Extra Neutral Gauge Boson at e^+e^- Linear
  Collider

abstract:
  The sensitivity to the $Z^\prime$ couplings of the processes $e^+e^-\to
l^+l^-,\bar{b}b$ and $\bar{c}c$ at the linear collider with $\sqrt{s}=500 GeV$
with initial beam polarization, for typical extended model examples are
studied. To this aim, the suitable integrated, polarized, observables directly
related to the helicity cross sections that carry information on the individual
$Z^\prime$ chiral couplings to fermions are used. We discuss the derivation of
separate, model-independent limits on the couplings in the case of no observed
indirect $Z^\prime$ signal within the expected experimental accuracy. In the
hypothesis that such signals were, indeed, observed we assess the expected
accuracy on the numerical determination of such couplings and the consequent
range of $Z^\prime$ masses where the individual models can be distinguished
from each other as the source of the effect.


title: Complete positivity and correlated neutral kaons

abstract:
  In relation with experiments on correlated kaons at phi-factories, it is
shown that the request of complete positivity is necessary in any physically
consistent description of neutral kaons as open quantum systems.


title: Hard exclusive photoproduction of $\Phi$ mesons

abstract:
  We calculate the differential cross section and single-polarization
observables for the reaction $\gamma p \to \Phi p$ within perturbative QCD,
treating the proton as a quark-diquark system. The phenomenological couplings
of gauge bosons to (spatially extended) diquarks and the quark-diquark
distribution amplitude of the proton are adopted from previous investigations
of baryon form factors and two-photon processes. Going beyond leading order, we
take into account hadron-mass effects by means of a systematic expansion in the
small parameter (hadron mass/ photon energy). With the $\Phi$-meson
distribution amplitude taken from the literature our predictions for the
differential cross section at $| t | \agt 4 \text{GeV}^2$ seem to provide a
reasonable extrapolation of the low-t data and are also comparable in magnitude
with the results of a two-gluon exchange model in which the gluons are
considered as a remnant of the pomeron. For momentum transfers of a few GeV
hadron-mass effects appear still to be sizeable.


title: Neutrino gravitational lensing

abstract:
  We study the lensing of neutrinos by astrophysical objects. At the difference
of photons, neutrinos can cross a stellar core; as a result the lens quality
improves. While Saturnians alone would benefit from this effect in the Sun,
similar effects could be considered for binary systems.


title:
QCD predictions for polarised deep inelastic scattering accompanied by a
  forward jet in the low x region of possible HERA measurements

abstract:
  We estimate the cross-section and asymmetry relevant for the production of
forward jets in polarised deep inelastic scattering in the region of small
values of $x$ which can be probed at possible polarised HERA measurements. The
kinematical cuts implemented in our analysis are the same as those which were
used in the unpolarised deep inelastic scattering at HERA. The calculations are
based on the double ln^2(1/x) resummation which controls the polarised deep
inelastic scattering for small values of the Bjorken parameter x. We show that
this resummation substantially enhances the corresponding cross-section and
asymmetry. The predicted value of the asymmetry is found to vary between -0.01
and -0.04 within the small x region which can possibly be probed at polarised
HERA measurements.


title:
On the lifetime of a cold dark matter particle and the cosmological
  diffuse photon background

abstract:
  We show that a Majorana heavy neutrino with a mass O(100TeV) is a good
candidate particle for cold dark matter. It can be responsible for the majority
of the cosmological diffuse photon background owing to lifetime of the order of
O(10^(25)s), dominantly fixed by the radiative two-body decay. The lifetime is
suppressed by two mechanisms: the leptonic GIM cancellation and the see-saw
weak coupling suppression. As a fermion cold dark matter particle, a heavy
neutrino favours the average mass density of the Universe constrained by the
Einstein-Cartan cosmology.


title: Selectron Mass Effects in Neutralino Production

abstract:
  We study the possibility to measure the masses of the selectrons in
neutralino production at an e^+ e^- linear collider with polarized beams. The
cross sections and polarization asymmetries of neutralinos with gaugino
character strongly depend on the masses of the exchanged selectrons. If the
usual GUT relations of the selectron masses in the MSSM are relaxed large
effects are possible especially in the polarization asymmetries. These can be
used to determine the masses of both selectrons.


title:
Effective Action and Electromagnetic Polarizabilities of Nucleons in QCD
  String Theory

abstract:
  The effective action for baryons in the external electromagnetic fields is
obtained on the basis of the QCD string theory. The area law of the Wilson loop
integral, the approximation of the Nambu-Goto straight-line strings, and the
asymmetric quark-diquark structure of nucleons are used to simplify the
problem. The spin-orbit and spin-spin interactions of quarks are treated as a
perturbation. With the help of the virial theorem we estimate the mean radii of
nucleons in terms of the string tension and the Airy function zeros. On the
basis of the perturbation theory in small external electromagnetic fields we
derive the electromagnetic polarizabilities of nucleons. The electric and
diamagnetic polarizabilities of a proton are $\bar{\alpha}_p= 10\times 10^{-4}
fm^3$, $\beta_p^{dia}=-8\times 10^{-4} fm^3$ and for a neutron we find
$\bar{\alpha}_n=4.2\times 10^{-4} fm^3 $, $\beta_n^{dia}= -5.4\times 10^{-4}
fm^3$. Reasonable values of the magnetic polarizabilities $\bar{\beta}_p=(5\pm
3)\times 10^{-4} fm^3$, $\bar{\beta}_n=(7.6\pm 3)\times 10^{-4} fm^3$ are
estimated using the $\Delta$ contribution to the paramagnetic polarizability of
the nucleons.


title: Intrinsic Charm in the Nucleon

abstract:
  The quark spin and flavor structure of the nucleon is discussed in the SU(4)
symmetry breaking chiral quark model. The spin and flavor contents for charm
quarks and anti-charm quarks are predicted and compared with the results given
by other models. The intrinsic charm quark contribution to the Ellis-Jaffe sum
rule is discussed.


title:
Four species neutrino oscillations at $\nu$-Factory: sensitivity and
  CP-violation

abstract:
  The prospects of measuring the leptonic angles and CP-odd phases at a {\em
neutrino factory} are discussed in the scenario of three active plus one
sterile neutrino. We consider the $\nu_\mu \raw \nu_e$ LSND signal. Its
associated large mass difference leads to observable neutrino oscillations at
short ($\sim 1$ km) baseline experiments. Sensitivities to the leptonic angles
down to $10^{-3}$ can be easily achieved with a 1 Ton detector. Longer baseline
experiments ($\sim 100$ km) with a 1 Kton detector can provide very clean tests
of CP-violation especially through tau lepton detection.


title:
Modelling Rho-Pion-Electromagnetic Interactions with an Effective
  Weinberg-Salam Theory

abstract: Withdrawn. Submittal to journal withdrawn by author in Dec 1999.


title: Non-perturbative Implications of Hadronic Interactions

abstract: This paper has been withdrawn.


title: Pandora: an Object-Oriented Event Generator for Linear Collider Physics

abstract:
  I describe an new event generator, pandora, which uses the C++ class
structure to allow a modular treatment of beams and particle production and
decay. (Talk presented at the 1999 International Workshop on Linear Colliders,
Sitges, Barcelona, Spain.)


title: Event Generators for Linear Collider Physics

abstract:
  I review the array of event generators which have been written to provide
simulations of high-energy e+e- reactions. (Session summary talk presented at
the 1999 International Workshop on Linear Colliders, Sitges, Barcelona, Spain.)


title: Physics Goals of the Linear Collider

abstract:
  I review the most important objectives of the physics program of a
next-generation e+e- linear collider. (Introductory theory lecture presented at
the 1999 International Workshop on Linear Colliders, Sitges, Barcelona, Spain.)


title:
Nonabelian Discrete Symmetries, Fermion Mass Textures and Large Neutrino
  Mixing

abstract:
  Nonabelian discrete groups are an attractive tool to describe fermion masses
and mixings. They have nonsinglet representations which seem particularly
suitable for distinguishing the lighter generations from the heavier ones.
Also, they do not suffer from the extra constraints a continuous group must
obey, e.g. limits on extra particles. Some of the simplest groups are the
nonabelian discrete subgroups of SO(3) and SU(2), the so called dihedral groups
D_n and dicyclic groups Q_2n, which both have only singlet and doublet
representations. After studying which vacuum expectation value (VEV) directions
of representations of dihedral and dicyclic groups preserve which subgroups, we
construct a simple model based on the group Q_6 \times Q_6. The model
reproduces the masses and mixings of all quarks and leptons, including
neutrinos. It has a large mixing angle in the mu - tau neutrino sector, in
accordance with the recent SuperKamiokande results, while keeping a small quark
mixing in the bottom - charm sector. The reason is similar to the one found in
the literature based on the SU(5) group: the large_left_ handed mixing angle in
the lepton sector corresponds to the large unphysical_right_ handed in the down
quark sector. The large mixing is also responsible for the different
hierarchies of the two heaviest families in the up and down sector, and can be
summarized as the order of magnitude relation: m_s/m_b \sim tan(theta_\mu\tau)
\sqrt{m_c/m_t}


title: Spectroscopy at B-factories Using Hard Photon Emission

abstract:
  The process of hard photon emission by initial electrons (positrons) at
B-factories is discussed. It is shown that studies of the bottomonium
spectroscopy will be feasible for the planned integrated luminosity of the
B-factory experiments.


title: Hadronic Atoms in QCD

abstract:
  We propose a non relativistic effective Lagrangian approach to study hadronic
atom observables in the framework of QCD (including photons). We apply our
formalism to derive a general expression for the width of the pi+pi- atom
decaying into two neutral pions. It contains all terms at leading and
next-to-leading order in isospin breaking. The result allows one to evaluate
the combination a0-a2 of pi-pi S-wave scattering lengths from pi+pi- atom
lifetime measurements, like the one presently performed by the DIRAC expeiment
at CERN.


title: Low Energy Constants from High Energy Theorems

abstract:
  New constraints on resonance saturation in chiral perturbation theory are
investigated. These constraints arise because each consistent saturation scheme
must map to a representation of the full QCD chiral symmetry group. The
low-energy constants of chiral perturbation theory are then related by a set of
mixing angles. It is shown that vector meson dominance is a consequence of the
fact that nature has chosen the lowest-dimensional nontrivial chiral
representation. It is further shown that chiral symmetry places an upper bound
on the mass of the lightest scalar in the hadron spectrum.


title:
Dual Quantum Electrodynamics: Dyon-Dyon and Charge-Monopole Scattering
  in a High-Energy Approximation

abstract:
  We develop the quantum field theory of electron-point magnetic monopole
interactions and more generally, dyon-dyon interactions, based on the original
string-dependent ``nonlocal'' action of Dirac and Schwinger. We demonstrate
that a viable nonperturbative quantum field theoretic formulation can be
constructed that results in a string {\em independent} cross section for
monopole-electron and dyon-dyon scattering. Such calculations can be done only
by using nonperturbative approximations such as the eikonal and not by some
mutilation of lowest-order perturbation theory.


title: On the Gauge Invariance of the Z-Boson Mass

abstract:
  The different schemes for the definition of the Z boson mass are analyzed. It
is shown that the scheme, defining the mass as pole of the real part of the Z
boson propagator and the width as the imaginary part of the propagator at the
same point results in the gauge dependent results for these parameters in a
two-loop approximation. On the other hand, the scheme, where the mass and width
are related to the position of the pole of the propagator in the complex plane
leads to the gauge independent result. It is argued that the gauge dependence
of mass and width does not contradicts to the gauge invariance of the
amplitude.


title:
Constraining the Selectron Mass in the Process e^- + gamma -->
  neutralino_1 +selectron_{L/R}^- --> e^- + 2 neutralino_1

abstract:
  With the process $e^-\gamma \to \tilde{\chi}_1^0 \tilde{e}_{L/R}^- \to e^-
\tilde{\chi}_1^0 \tilde{\chi}_1^0$ it is possible to constrain selectron masses
above the kinematical limit of the pair production process in $e^+e^-$
colliders. We investigate these mass ranges and discuss the possibility to test
the renormalization group equations for the selectron masses.


title: Weak Radiative Hyperon Decays: Questioning the Basics

abstract:
  Main theoretical approaches to weak radiative hyperon decays are briefly
reviewed. It is emphasized that only approaches with great predictive power
should be seriously considered when seeking a resolution of the puzzle
presented by observed large negative asymmetry alpha (Sigma ^+ --> p gamma). In
such cases, asymmetry in the Xi ^0 --> Lambda gamma decay is always large while
its sign is positive (negative) if Hara's theorem is violated (satisfied).
Measuring this asymmetry is therefore crucial for determining whether the large
value of alpha (Sigma ^+ --> p gamma) is due to large SU(3) breaking or to some
deeper reason. Some arguments suggesting that violation of Hara's theorem might
be a feature of Nature, and hints as to its possible origin are also given.


title: Determination of the weak phase gamma=arg(V_ub^*)

abstract:
  Various strategies for extracting or constraining the weak phase gamma with
controlled theoretical uncertainties are reviewed. Measurements of the rates
for the hadronic decays B^+- -> pi K provide largely model-independent
information on gamma. Hadronic uncertainties enter only at the level of
nonfactorizable contributions to the decay amplitudes that are power-suppressed
in Lambda/m_b and, simultaneously, violate SU(3) flavor symmetry or are doubly
Cabibbo suppressed. In addition, these decays have a rich potential for probing
physics beyond the Standard Model. Alternative proposals for learning gamma are
also discussed briefly.


title:
The Photon Wave Function in Non-forward Diffractive Scattering with
  Non-vanishing Quark Masses

abstract:
  The light-cone Photon wave function in explicit helicity states, valid for
massive quarks and in both momentum and configuration space, is presented by
considering the leading order photon-proton hard scattering, i.e., the
splitting quark pair scatters with the proton in the Regge limit. Further we
apply it to the diffractive scattering at nonzero momentum transfer and reach a
similar factorization as in the case of zero momentum transfer.


title: Dark matter in the universe

abstract:
  Cosmological arguments proving that the universe is dominated by invisible
non-baryonic matter are reviewed. Possible physical candidates for dark matter
particles are discussed. A particular attention is paid to non-compensated
remnants of vacuum energy, to the question of stability of super-heavy relics,
cosmological mass bounds for very heavy neutral lepton, and some other more
exotic possibilities.


title:
Nonequilibrium chiral perturbation theory and disoriented chiral
  condensates

abstract:
  We analyse the extension of Chiral Perturbation Theory to describe a meson
gas out of thermal equilibrium. For that purpose, we let the pion decay
constant be a time-dependent function and work within the Schwinger-Keldysh
contour technique. A useful connection with curved space-time QFT allows to
consistently renormalise the model, introducing two new low-energy constants in
the chiral limit.
  We discuss the applicability of our approach within a Relativistic Heavy-Ion
Collision environment. In particular, we investigate the formation of
Disoriented Chiral Condensate domains in this model, via the parametric
resonance mechanism.


title: Top quark production near threshold

abstract:
  The present theoretical status of top quark pair production near threshold at
(future) $e^+ e^-$ ($\mu^+\mu^-$) colliders is summarized.


title: Quantum Transport Equations for a Scalar Field

abstract:
  We derive quantum Boltzmann equations from Schwinger-Dyson equations in
gradient expansion for a weakly coupled scalar field theory with a spatially
varying mass. We find that at higher order in gradients a full description of
the system requires specifying not only an on shell distribution function but
also a finite number of its derivatives, or equivalently its higher moments.
These derivatives describe quantum coherence arising as a consequence of
localization in position space. We then show that in the limit of frequent
scatterings coherent quantum effects are suppressed, and the transport
equations reduce to the single Boltzmann equation for particle density, in
which particles flow along modified semiclassical trajectories in phase space.


title:
Three and Two-Point One-Loop Integrals in Heavy Particle Effective
  Theories

abstract:
  We give a complete analytical computation of three and two-point loop
integrals occurring in heavy-particle theories, involving a velocity change,
for arbitrary real values of the external masses and residual momenta.


title: Paramagnetic effect of light quark loops on Chiral Symmetry Breaking

abstract:
  We argue that light quark loops produce a paramagnetic suppression of
infrared-sensitive order parameters such as <qq>, as the number N_f of light
fermions increases. The possibly strong dependence of <qq> on N_f is related to
the observed Zweig rule violation in the scalar channel. Presuming the
existence of a chiral phase transition for not too large N_f, we discuss the
phenomenological possibilities of separately determining the two-flavour and
three-flavour condensates and the quark mass ratio r=2m_s/(m_u+m_d). The issue
is closely related to the interpretation of new forthcoming precise pi-pi data
at low energy.


title: Measuring the quark condensate from the decays tau -> 3 pi + nu(tau)

abstract:
  The possibility of detecting the S-wave of the decays tau -> 3 pi + nu(tau)
in the threshold region is explored, with emphasis on the sensitivity to the
size of the quark antiquark condensate <qq>.


title: Quark Spin and Orbital Angular Momentum in the Baryon

abstract:
  The spin and orbital angular momentum carried by different quark flavors in
the nucleon are calculated in the SU(3) chiral quark model with
symmetry-breaking. The model is extended to all octet and decuplet baryons. In
this model, the reduction of the quark spin, due to the spin dilution in the
chiral splitting processes, is transferred into the orbital motion of quarks
and antiquarks. The orbital angular momentum for each quark flavor in the
proton as function of the partition factor $\kappa$ and the chiral splitting
probability $a$ is shown. Although the total amount of the quark spin reduction
is canceled by the the equal amount increase of the quark orbital angular
momentum, the cancellation does not apply to each quark flavor. Especially, the
cancellation between the spin and orbital contributions in the baryon magnetic
moment is discussed. Comparisons of our results with other models are also
shown.


title: On nature of scalar a_0(980) and f_0(980)-mesons

abstract:
  It is presented a critical consideration of all unusual properties of the
scalar a_0(980) and f_0(980)-mesons in the four-quark, two-quark and molecular
models. The arguments are adduced that the four-quark model is more preferable.
It is discussed the complex of experiments that could finally resolve this
issue.


title: Spatial structure of quark Cooper pairs in a color superconductor

abstract:
  Spatial structure of Cooper pairs with quantum numbers color 3^*, I=J=L=S=0
in ud 2 flavor quark matter is studied by solving the gap equation and
calculating the coherence length in full momentum range without the weak
coupling approximation. Although the gap at the Fermi surface and the coherence
length depend on density weakly, the shape of the r-space pair wave function
varies strongly with density. This result indicates that quark Cooper pairs
become more bosonic at higher densities.


title: Collider Signatures of Sneutrino Cold Dark Matter

abstract:
  Decays of sneutrinos are considered in the case that in the presence of
lepton-number violation in the sneutrino sector the lighter tau-sneutrino is
the Lightest Supersymmetric Particle and the Cold Dark Matter in the Universe.
In such circumstances the signals from sparticle decays differ considerably
from the ``standard'' case where the lightest neutralino is the Lightest
Supersymmetric Particle and it is found that in a wide range of parameters
compatible with the sneutrino Cold Dark Matter hypothesis signatures
characteristic for such a scenario should be easily observable at for example a
Next Linear Collider.


title:
Polarized Single Top Production at Leptonic Colliders from Broken R
  Parity Interactions Incorporating CP Violation

abstract:
  The contribution from the R parity violating interactions in the associated
production of a top quark with a charm antiquark is examined for high energy
leptonic colliders. We concentrate on the reactions associated with the
semileptonic top decay. A set of characteristic dynamical distributions for the
signal events is evaluated and the results contrasted against those from the
standard model W-boson pair production background. Next, we turn to a study of
a CP-odd observable, associated with the top spin, which leads to an asymmetry
in the energy distribution of the emitted charged leptons for the pair of
CP-conjugate final states, $b \bar l \nu \bar c$ and $ \bar b l \bar \nu c $. A
non vanishing asymmetry arises from a CP-odd phase, embedded in the R parity
violating coupling constants, through interference terms between the R parity
violating amplitudes at both the tree and loop levels.


title: Theory Summary Talk

abstract:
  A summary is presented of the more theoretical aspects of the presentations
made at Hyperon~99. In addition, some material is covered which was not
presented at the symposium but which I feel is pertinent to the main theme of
hyperons and/or, more in particular, to discussions conducted during the
symposium.


title: On soft gluon effects in deep-inelastic structure functions

abstract:
  The behaviour of the quark coefficient functions in deep-inelastic scattering
is investigated for large values of the Bjorken variable x. By combining
results of soft-gluon resummation and fixed-order calculations, we determine
the coefficients of the four leading large-x logarithms, alpha_s^k
[{ln(1-x)}^{2k-l}/(1-x)]_+, l = 1, ...4, to all orders in the strong coupling
constant alpha_s. This result includes two more terms for the three-loop
coefficient functions than previously specified in the literature. The effect
of the fifth logarithmic contribution is approximately evaluated. The terms
derived here are required, but also seem to be sufficient, for a reliable
representation of the coefficient functions at large x.


title: Three flavor neutrino oscillations in matter

abstract:
  We derive analytic expressions for three flavor neutrino oscillations in the
presence of matter in the plane wave approximation using the Cayley-Hamilton
formalism. Especially, we calculate the time evolution operator in both flavor
and mass bases. Furthermore, we find the transition probabilities, matter mass
squared differences, and matter mixing angles all expressed in terms of the
vacuum mass squared differences, the vacuum mixing angles, and the matter
density. The conditions for resonance in the presence of matter are also
studied in some examples.


title: Stability of Multiquark Systems

abstract:
  We give a brief review of developments in the field of exotic hadrons formed
of more than three quarks and/or antiquarks. In particular we discuss the
stability of multiquark systems containing heavy flavours. We show that the
gluon exchange model and the chiral constituent quark model based on Goldstone
boson (pseudoscalar meson) exchange give entirely different results.


title: Production of fast hadron leader by QCD process

abstract:
  An algorithm of Monte Carlo code for the production of fast hadron leader in
the (anti)proton-proton interaction by QCD process is discussed.


title: Kaon CP violation and radiative corrections

abstract:
  This paper has been withdrawn by the author, because a profoundly overhauled
and improved version, also with a new title and two more authors, has now been
submitted to the arXiv, with no. hep-ph/0310059. In view of the elapsed time
and the very substantial changes in the original paper, a new e-print was
judged more appropriate than just a replacement.


title: Generalized Pions in Dense QCD

abstract:
  QCD superconductors in the color-flavor-locked (CFL) phase sustain light
Goldstone modes (that will be referred to as generalized pions) that can be
described as pairs of particle and/or hole excitations around a gapped Fermi
surface. In weak coupling and to leading logarithm accuracy, their form factor,
mass and decay constant can be evaluated exactly. These modes are found to
satisfy an axial-Ward-identity, constraining the mass of the Goldstone modes in
the CFL phase.


title:
Estimate of the Three-Loop Perturbative Contribution to Inclusive
  Semileptonic b to u Decays

abstract:
  We utilize asymptotic Pade-approximant methods to estimate the three-loop
order MS bar-scheme coefficients within the inclusive semileptonic b to u decay
rate for four and five active quark flavours. The estimates we obtain for the
three renormalization-group-accessible coefficients within the three-loop
contribution are all found to be within 5.1% of their true values, using a
least-squares procedure in conjunction with an asymptotic Pade-approximant
estimate of the three-loop term over the entire $\mu \ge m_b$ domain. Given the
input values $\alpha_s(M_Z) = 0.118 \pm 0.004$ and $m_b(m_b) =4.17 \pm 0.05
GeV$, the three-loop expression for the purely-perturbative contribution to the
decay rate is minimally sensitive to renormalization scale at $\mu = 1.775
GeV$, at which scale the three-loop contribution is estimated to be only 1.4%
of the leading tree-order contribution. We estimate the full perturbative decay
rate to be $192\pi^3\Gamma(b\to u\bar\nu_\ell\ell^-)/(G_F^2| V_{ub}|^2) = 2070
{\rm GeV^5} \pm 16%$, inclusive of theoretical uncertainties from series
truncation, the input parameters, and the estimation procedure.


title: Soft Dipole Pomeron in hadronic elastic and in deep inelastic scattering

abstract:
  A brief review on the Dipole Pomeron model is given. The model not only
describes data on hadron-hadron interactions, but also allows to describe data
on the proton structure function with a $Q^2$ independent intercept. Moreover
the chosen Dipole Pomeron has an intercept equal to one and does not violate
unitarity limit on the total elastic cross-section.


title:
Large CP Phases and the Cancellation Mechanism in EDMs in SUSY, String
  and Brane Models

abstract:
  We show that EDMs obey a simple approximate scaling under the transformation
$m_0\to \lambda m_0,m_{{1/2}}\to \lambda m_{{1/2}}$ in the large $\mu$ region
when $\mu$ itself obeys the same scaling, ie., $\mu \to \lambda \mu$. In the
scaling region the knowledge of a single point in the MSSM parameter space
where the cancellation in the EDMs occur allows one to generate a trajectory in
the $m_0-m_{{1/2}}$ plane where the cancellation mechanism holds and the EDMs
are small. We illustrate these results for MSSM with radiative electro-weak
symmetry breaking constraints. We also discuss a class of D brane models based
on Type IIB superstring compactifications which have non-universal phases in
the gaugino mass sector and allow large CP violating phases consistent with the
EDM constraints through the cancellation mechanism. The scaling in these D
brane models and in a heterotic string model is also discussed.


title: Matter Effects on Long Baseline Neutrino Oscillation Experiments

abstract:
  We calculate matter effects on neutrino oscillations relevant for long
baseline neutrino oscillation experiments. In particular, we compare the
results obtained with simplifying approximations for the density profile in the
Earth versus results obtained with actual density profiles. We study the
dependence of the oscillation signals on both $E/\Delta m^2_{atm.}$ and on the
angles in the leptonic mixing matrix. The results show quantitatively how
matter effects can cause significant changes in the oscillation signals,
relative to vacuum oscillations and can be useful in amplifying these signals
and helping one to obtain measurements of mixing parameters and the magnitude
and sign of $\Delta m^2$.


title: On the Oscillations of the Tensor Spin Structure Function

abstract:
  The smallness of the deuteron tensor spin structure function is the necessary
condition to extract neutron $g_1$ function neglecting the nuclear effects. The
oscillating behavior of the quark tensor spin structure function leading to the
zero first moment is shown to be the straightforward consequence of the
factorization property and Lorentz covariance. For the singlet contribution the
momentum conservation leads to the zero second moment also. The deviations from
zero directly measure the gluon contribution.


title: An Open Universe from Valley Bounce

abstract:
  It appears difficult to construct a simple model for an open universe based
on the one bubble inflationary scenario. The reason is that one needs a large
mass to avoid the tunneling via the Hawking Moss solution and a small mass for
successful slow-rolling. However, Rubakov and Sibiryakov suggest that the
Hawking Moss solution is not a solution for the false vacuum decay process
because it does not satisfy the boundary condition. Hence, we have reconsidered
the arguments for the defect of the simple polynomial model. We point out the
possibility that one of the valley bounce belonging to a valley line in the
functional space represents the decay process instead of the Hawking Moss
solution. Under this presumption, we show an open inflation model can be
constructed within the polynomial form of the potential so that the
fluctuations can be reconciled with the observations.


title:
MSSM Higgs-Boson Production at Hadron Colliders with Explicit CP
  Violation

abstract:
  Gluon fusion is the main production mechanism for Higgs bosons with masses up
to several hundred GeV in $pp$ collisions at the CERN Large Hadron Collider. We
investigate the effects of the CP-violating phases on the fusion process
including both the sfermion-loop contributions and the one-loop induced
CP-violating scalar-pseudoscalar mixing in the minimal supersymmetric standard
model. With a universal trilinear parameter assumed, every physical observable
involves only the sum of the phases of the universal trilinear parameter $A$
and the higgsino mass parameter $\mu$. The phase affects the lightest
Higgs-boson production rate significantly through the neutral Higgs-boson
mixing and, for the masses around the lightest stop-pair threshold, it also
changes the production rate of the heavy Higgs bosons significantly through
both the stop and sbottom loops and the neutral Higgs-boson mixing.


title:
Radiative Decays of Heavy Mesons and the Determination of the Strong
  g-Coupling

abstract:
  The strong g-coupling characterizes the interaction of heavy mesons with
pions in typical vertices $H^*H\pi$, $H^*H^*\pi$, where $(H^*;H)$ stands for
vector and pseudoscalar $(B^*;B)$ or $(D^*;D)$ heavy mesons. Its estimation by
different theoretical methods has led to a wide range of possible values. We
describe a new approach to the determination of g, which exploits the rare
radiative decays $B^*\to B\gamma\gamma$ and $D^*\to D\gamma\gamma$. It is shown
that the branching ratio of $D^*\to D\gamma\gamma$ can be expressed as a
function of a single unknown $g$ and we calculate it to be in the measurable
range between $1.6\times 10^{-6}$ and $3.3\times 10^{-5}$ for 0.25 < g < 1.


title: The Standard Model in Its Other Phase

abstract:
  The standard model of particle physics is analyzed for the case of a Higgs
potential not favoring spontaneous electroweak symmetry breaking to gain
insight into the physics of the standard model. Electroweak breaking still
takes place, and quarks and leptons still acquire masses but through bosonic
technicolor. This ``other'' phase of the standard model exhibits interesting
phenomena.


title: Chiral Vortons and Cosmological Constraints on Particle Physics

abstract:
  We investigate the cosmological consequences of particle physics theories
that admit stable loops of current-carrying string - vortons. In particular, we
consider chiral theories where a single fermion zero mode is excited in the
string core, such as those arising in supersymmetric theories with a D-term.
The resulting vortons formed in such theories are expected to be more stable
than their non-chiral cousins. General symmetry breaking schemes are considered
in which strings formed at one symmetry breaking scale become current-carrying
at a subsequent phase transition. The vorton abundance is estimated and
constraints placed on the underlying particle physics theories from
cosmological observations. Our constraints on the chiral theory are
considerably more stringent than the previous estimates for more general
theories.


title: Possible Non-Higgs Symmetry Breaking Phases in Gauge Theories

abstract:
  This paper has been withdrawn, because the argument for generation of
Goldstone modes is incorrect.


title:
Stochastic treatment of Disoriented Chiral Condensates within a Langevin
  description

abstract:
  Applying a microscopically motivated semi-classical Langevin description of
the linear sigma model we investigate for various different scenarios the
stochastic evolution of a disoriented chiral condensate (DCC) in a rapidly
expanding system. Some particular emphasize is put on the numerical realisation
of colored noise in order to treat the underlying dissipative and nonmarkovian
stochastic equations of motion. A comparison with an approximate markovian
(i.e. instantaneous) treatment of dissipation and noise will be made in order
to identify the possible influence of memory effects in the evolution of the
chiral order parameter. Assuming a standard Rayleigh cooling term to simulate a
D-dimensional scaling expansion we present the probability distribution in the
low momentum pion number stemming from the relaxing zero mode component of the
chiral field. The best DCC signal is expected for initial conditions centered
around $<\sigma > \approx 0 $ as would be the case of effective light `pions'
close to the phase transition. By choosing appropriate idealized global
parameters for the expansion our findings show that an experimentally feasible
DCC, if it does exist in nature, has to be a rare event with some finite
probability following a nontrivial and nonpoissonian distribution on an event
by event basis. DCCs might then be identified experimentally by inspecting
higher order factorial cumulants $\theta_m$ ($m\ge 3$) in the sampled
distribution.


title: New Color Decompositions for Gauge Amplitudes at Tree and Loop Level

abstract:
  Recently, a color decomposition using structure constants was introduced for
purely gluonic tree amplitudes, in a compact form involving only the linearly
independent subamplitudes. We give two proofs that this decomposition holds for
an arbitrary number of gluons. We also present and prove similar decompositions
at one loop, both for pure gluon amplitudes and for amplitudes with an external
quark-antiquark pair.


title: The Triangle Anomaly in the Triple-Regge Limit

abstract:
  The U(1) triangle anomaly is present, as an infra-red divergence, in the
six-reggeon triple-regge interaction vertex obtained from a maximally
non-planar Feynman diagram in the full triple-regge limit of three-to-three
quark scattering.


title: Nucleon Spin Content from Elastic Form Factor Data

abstract:
  I use the formalism of skewed parton distributions (SPD) to describe elastic
form factors of the nucleon. The results are consistent with approximate dipole
behavior of $G_{Mp}(Q^2)$ and recent JLab data for the ratio of the proton form
factors $G_{Ep}/G_{Mp}$ at $Q^2\leq 3.5$ GeV$^2$. Using the Angular Momentum
Sum Rule, I obtain a numerical estimate for the valence quark contributions to
the nucleon spin at the level of 50%, with their orbital angular momentum {\it
included}. When combined with polarized DIS measurements, this result indicated
that the orbital angular momentum of quarks contributes about 25% to the
nucleon spin.


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

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


title:
Factorization Approach for the $\Delta I=1/2$ Rule and
  $\epsilon'/\epsilon$ in Kaon Decays

abstract:
  The $\Delta I=1/2$ rule and direct CP violation $\epsilon'/\epsilon$ in kaon
decays are studied within the framework of the effective Hamiltonian approach
in conjunction with generalized factorization for hadronic matrix elements. We
identify two principal sources responsible for the enhancement of A0/A_2: the
vertex-type as well as penguin-type corrections to the matrix elements of
four-quark operators, which render the physical amplitude renormalization-scale
and -scheme independent, and the nonfactorized effect due to soft-gluon
exchange, which is needed to suppress the $\Delta I=3/2$ $K\to\pi\pi$
amplitude. Contrary to the chiral approach which is limited to light meson
decays and fails to reproduce the A2 amplitude, the aforementioned approach for
dealing with scheme and scale issues is applicable to heavy meson decays. We
obtain A0/A2=13-15 if $m_s$(1 GeV) lies in the range (125-175)MeV. The bag
parameters $B_i$, which are often employed to parametrize the scale and scheme
dependence of hadronic matrix elements, are calculated in two different
renormalization scehemes. It is found that $B_8^{(2)}$ and $ B_6^{(0)}$, both
of order 1.5 at $\mu=1$ GeV, are nearly $\gamma_5$ scheme independent, whereas
$B^{(0)}_{3,5,7}$ as well as $B_7^{(2)}$ show a sizable scheme dependence.
Moreover, only $B_{1,3,4}^{(0)}$ exhibit a significant $m_s$ dependence, while
the other $B$-parameters are almost $m_s$ independent. For direct CP violation,
we obtain $\epsilon'/\epsilon=(0.7-1.1)\times 10^{-3}$ if $m_s(1 {\rm
GeV})=150$ MeV and $\epsilon'/\epsilon=(1.0-1.6)\times 10^{-3}$ if $m_s$ is as
small as indicated by some recent lattice calculations.


title:
The $B\to X_sl^+l^-$ and $B\to X_s \gamma$ decays with the fourth
  generation

abstract:
  If the fourth generation fermions exist, the new quarks could influence the
branching ratios of the decays of $B\to X_s \gamma$ and $B\to X_sl^+l^-$. We
obtain two solutions of the fourth generation CKM factor
$V^{*}_{t^{'}s}V_{t^{'}b}$ from the decay of $B\to X_s \gamma$. We use these
two solutions to calculate the new contributions of the fourth generation quark
to Wilson coefficients of the decay of $B\to X_sl^+l^-$. The branching ratio
and the forward-backward asymmetry of the decay of $B\to X_sl^+l^-$ in the two
cases are calculated. Our results are quite different from that of SM in one
case, almost same in another case. If Nature chooses the formmer, the $B$ meson
decays could provide a possible test of the forth generation existence.


title: Mesons in non-local chiral quark models

abstract:
  Vector meson correlators are studied in effective chiral quark models with
both local and non-local regulators. A set of sum rules based on dispersion
relations is derived, which allows for a comparison of model predictions to
data. We show that the two Weinberg sum rules for vector correlators hold in
the non-local model.


title: Spin Effects in Diffractive $Q \bar Q$ Production and Compass Experiment

abstract:
  We calculate the double spin asymmetry of the diffractive $Q \bar Q$ and
vector meson leptoproduction at COMPASS energies. We analyze dependences of the
asymmetry on the structure of the Pomeron-proton coupling. It is shown that it
is difficult to study the spin structure of the Pomeron coupling with the
proton from the A_{ll} asymmetry. The A_{lT} asymmetry might be an appropriate
object for this investigation.


title: QCD Sum Rules for Heavy Flavors

abstract:
  I give a short summary of QCD sum rule results for hadrons involving a heavy
quark, with emphasis on recent developments.


title:
Reassessment of the Collins Mechanism for Single-spin Asymmetries and
  the behavior of Delta d(x) at large x

abstract:
  It is shown that the Collins mechanism explanation of the transverse
single-spin asymmetries in p^{\uparrow} p -> \pi X leads to a transversely
polarized d quark density Delta_T d(x) which violates the Soffer bound when one
uses several standard forms for the longitudinally polarized d quark density
Delta d(x) obtained from polarized deep inelastic scattering. Imposition of the
Soffer bound with these Delta d(x) yields results in hopeless disagreement with
the data. Remarkably, imposition of the Soffer bound, but using
parametrizations of Delta d(x) that respect the PQCD condition Delta q(x) /
q(x) -> 1 as x -> 1, leads to an excellent fit to most of the data. The
implications for the polarized DIS neutron longitudinal asymmetry A_1^n at
large x are dramatic.


title:
Sensitivity to the Gravitino mass from single-photon spectrum at TESLA
  Linear Collider

abstract:
  The spectrum of single-photon events detected in the forward and in the
barrel region of a TESLA linear collider detector was studied in order to
investigate the production of superlight Gravitino pairs associated with a
photon.


title: CPT violation and cascade decays

abstract:
  In tagged cascade decays of the type P^0 (P^0-bar) -> M^0 / M^0-bar X -> f X
there are two complex CPT-violating parameters: one in P^0 - P^0-bar mixing,
the other one in M^0 - M^0-bar mixing. I analyze those decays and find that, in
principle, the former parameter can be extracted from a careful comparison of
their time dependences. CPT violation in M^0 - M^0-bar mixing, on the other
hand, always appears entangled with ratios of decay amplitudes and cannot be
extracted.


title: Pomeron: Beyond the Standard Approach

abstract:
  We discuss the experimental evidence supporting the concept of universality
of the rapidity gap probability in soft and hard diffraction, relate the gap
probability to hadronic parton densities, and present a phenomenological model
of diffraction in which the structure of the Pomeron is derived from the
structure of the parent hadron. Predictions for diffractive deep inelastic
scattering are compared with data.


title:
Phenomenological Study of Strong Decays of Heavy Hadrons in Heavy Quark
  Effective Theory

abstract:
  The application of the tensor formalism of the heavy quark effective theory
(HQET) at leading order to strong decays of heavy hadrons is presented.
Comparisons between experimental and theoretical predictions of ratios of decay
rates for B mesons, D mesons and kaons are given. The application of HQET to
strange mesons presents some encouraging results. The spin-flavor symmetry is
used to predict some decay rates that have not yet been measured.


title: Non anomalous U(1)_H gauge model of flavor

abstract:
  A non anomalous horizontal $U(1)_H$ gauge symmetry can be responsible for the
fermion mass hierarchies of the minimal supersymmetric standard model. Imposing
the consistency conditions for the absence of gauge anomalies yields the
following results: i) unification of leptons and down-type quarks Yukawa
couplings is allowed at most for two generations. ii) The $\mu$ term is
necessarily somewhat below the supersymmetry breaking scale. iii) The
determinant of the quark mass matrix vanishes, and there is no strong $CP$
problem. iv) The superpotential has accidental $B$ and $L$ symmetries. The
prediction $m_{\rm up}=0$ allows for an unambiguous test of the model at low
energy.


title: New features in DPMJET version II.5

abstract:
  DPMJET is a Monte Carlo model for sampling of hadron-hadron, hadron-nucleus,
nucleus-nucleus and neutrino-nucleus interactions at accelerator and Cosmic Ray
energies according to the two-component Dual Parton Model. Here we describe new
features in version DPMJET-II.5: Implementation of new DPM diagrams for an
improved description of baryon stopping in nuclear collisions and improvements
in the calculation of Glauber cross sections. The new diagrams allow two quite
different extrapolations of the model to the highest Cosmic Ray energies. The
new version of the model is compared to experimental data on hadron-hadron,
hadron-nucleus and nucleus-nucleus collisions.


title:
Amplification of Isocurvature Perturbations induced by Active-Sterile
  Neutrino Oscillations

abstract:
  We show how the generation of a lepton number in the Early Universe induced
by active-sterile neutrino oscillations, in presence of small baryon number
inhomogeneities, gives rise to the formation of lepton domains, regions with
different values of active neutrino chemical potential. The structure of these
domains reflects the spectral features of the baryon number inhomogeneities
that generated it. An interesting aspect of the mechanism is that the size of
lepton domains can be super-horizon.


title: Rare Decays of Heavy Quarks - Searching Ground for New Physics

abstract:
  The search for new physics beyond the standard model is proceeding nowadays
intensively along experimental and theoretical lines. We review here the sector
of charm radiative decays in this context. The calculation of $D\to V\gamma$,
$D\to \ell^+\ell^-\gamma$ transitions reveals their unequivocal dominance by
long-distance contributions. On the other hand, the beauty-conserving
charm-changing electroweak transition $B_c\to B_u^*\gamma$ is shown to have
unique properties which make it a promising avenue in the search for new
physics. We describe a calculation of short- and long-distance contributions to
this decay which finds them to be of comparable size. The branching ratio of
this decay in the standard model is estimated to be $\simeq 10^{-8}$.


title: Review on alpha_s at LEP

abstract:
  To measure the strong coupling alpha_s from event shape observables two
ingredients are necessary. A perturbative prediction containing the dependence
of observables on alpha_s and a description of the hadronisation process to
match the perturbative prediction with the hadronic data.
  As perturbative prediction O(alpha_s^2), NLLA and combined calculations are
available. Beside the well known Monte-Carlo based models also analytical
predictions, so called power corrections, exist to describe the hadronisation.
Advantages and disadvantages of the different resulting methods for determining
the strong coupling and its energy dependence will be discussed, the newest
DELPHI results will be presented, and an overview of the LEP results will be
included.


title:
Connection between closeness of classical orbits and the factorization
  of radial Schr\"{o}dinger equation

abstract:
  It was shown that the Runge-Lenz vector for a hydrogen atom is equivalent to
the raising and lowering operators derived from the factorization of radial
Schr\"{o}dinger equation. Similar situation exists for an isotropic harmonic
oscillator. It seems that there may exist intimate relation between the
closeness of classical orbits and the factorization of radial Schr\"{o}dinger
equation. Some discussion was made about the factorization of a 1D
Schr\"{o}dinger equation.


title: Quantum Magnetic Collapse

abstract:
  We study the thermodynamics of degenerate electron and charged vector boson
gases in very intense magnetic fields. In degenerate conditions of the electron
gas, the pressure transverse to the magnetic field $B$ may vanish, leading to a
transverse collapse. For W-bosons an instability arises because the
magnetization diverges at the critical field B_c = M_W^2/e. If the magnetic
field is self-consistently maintained, the maximum value it can take is of the
order of $2B_c/3$, but in any case the system becomes unstable and collapses.


title: Quarkonia and Hybrids from the Lattice

abstract:
  The status of lattice determinations of quarkonia and hybrid meson spectra is
presented and compared with experiment. Both quenched and unquenched results
are discussed. Hybrid meson decays are considered.


title: Kt effect for the top quark production in hadronic collisions

abstract:
  Withdrawn by arXiv administration because authors have forged affiliations
and acknowledgements, and have not adequately responded to charges
[hep-th/9912039] of unattributed use of verbatim material.


title: JetViP 2.1: the hbook version

abstract:
  We present an update of the JetViP 1.1 program for performing fixed NLO
calculations in jet production including direct and resolved components in a
continuous range of photon virtuality Q^2. The new version allows to access the
full event record on the parton level. The program is set up such that hbook
can be used to fill histograms. The phase space generator has been optimized
and the azimuthal dependence of the cross sections is taken into account in LO.
We comment on recent comparisons between various NLO programs for jet
production at HERA. We demonstrate that the \Sum E_T cut for dijet cross
sections is not infrared safe.


title:
Mass formulas and thermodynamic treatment in the mass-density-dependent
  model of strange quark matter

abstract:
  The previous treatments for strange quark matter in the quark
mass-density-dependent model have unreasonable vacuum limits. We provide a
method to obtain the quark mass parametrizations and give a self-consistent
thermodynamic treatment which includes the MIT bag model as an extreme. In this
treatment, strange quark matter in bulk still has the possibility of absolute
stability. However, the lower density behavior of the sound velocity is
opposite to previous findings.