title: Semileptonic B Decays as a Probe of New Physics

abstract:
  Physics beyond the Standard Model could be measured indirectly, through its
effects on Standard Model observables. One place to look for such effects is in
the semileptonic decays of B mesons. In order to constrain the possible role of
new physics on semileptonic B decays, we present the most general low energy
effective Lagrangian constructed from all dimension six four-fermion operators
that contribute to the process b-> c l- nu. We then use it to compute the
corrections due to new physics to the differential decay rates for the
exclusive processes B-> D(*) l- nu, as well as the inclusive decays B-> X l-
nu. Both inclusive and exclusive rates are expressed in terms of a set of
parameters that characterize the types of four-fermion interactions that can be
induced by physics beyond the Standard Model. Although it is not particularly
useful to carry out a full analysis until data from the next generation of B
factories becomes available, here we illustrate how the existing experimental
results can be used to constrain some of these parameters.


title: Testing the Solar Neutrino Conversion with Atmospheric Neutrinos

abstract:
  Neutrino oscillations with parameters relevant for the large mixing solution
of the solar neutrino problem ($\Delta m^2_{21} = (2 - 20) \cdot 10^{-5}$
eV$^2$, $\sin^2 2\theta_{12} > 0.65$) can lead to observable (up to 10 - 12 %)
excess of the e-like events in the sub-GeV atmospheric neutrino sample. The
excess has a weak zenith angle dependence in the low energy part of the sample
and strong zenith angle dependence in the high energy part. The effect rapidly
decreases with energy of neutrinos, it is suppressed in the multi-GeV sample.
These signatures allow to disentangle the effect from other possible
explanations of the excess. The possibility of change of the sign of the
up-down asymmetry of the excess with energy (positive in the sub-GeV region and
negative in the multi-GeV region) is marked. The predicted properties of excess
are in agreement with SuperKamiokande data.


title: Discrete Ambiguities in the Measurement of the Weak Phase Gamma

abstract:
  Several time-independent methods have been devised for measuring the phase
gamma of the Cabibbo-Kobayashi-Maskawa unitarity triangle. It is shown that
such measurements generally suffer from discrete ambiguity which is at least
8-fold, not 4-fold as commonly stated. This has serious experimental
implications, which are explored in methods involving B->DK decays. The
measurement sensitivity and new physics discovery potential are estimated using
a full Monte Carlo detector simulation with realistic background estimates.


title: Polarized proton-deuteron Drell-Yan processes and parton distributions

abstract:
  We show in general that there are 108 structure functions in the
proton-deuteron Drell-Yan processes. However, there exist only 22 finite ones
after integrating the cross section over the virtual-photon transverse momentum
\vec Q_T or after taking the limit Q_T->0. There are 11 new structure functions
in comparison with the ones of the proton-proton reactions, and they are
related to the tensor structure of the deuteron. Parton-model analyses indicate
an important tensor structure function V_T^{UQ_0}, which can be measured by a
quadrupole spin asymmetry. The Drell-Yan process has an advantage over lepton
reactions in finding tensor polarized antiquark distributions. We hope that our
studies will be realized in the next-generation RHIC-Spin project and other
ones.


title:
Heavy Quark Expansion and Preasymptotic Corrections to Decay Widths in
  the 't Hooft Model

abstract:
  We address nonperturbative power corrections to inclusive decay widths of
heavy flavor hadrons in the context of the 't Hooft model (two-dimensional QCD
at N_c->oo), with the emphasis on the spectator-dependent effects sensitive to
the flavor of the spectator. The summation of exclusive widths is performed
analytically using the `t Hooft equation. We show that the 1/m_Q expansion of
both the Weak Annihilation and Pauli Interference widths coincides with the OPE
predictions, to the computed orders. Violation of local duality in the
inclusive widths is quantified, and the new example is identified where the OPE
prediction and the actual effect are completely saturated by a single final
state. The qualitative aspects of quark hadronization emerging from the
analysis in the 't Hooft model are discussed. Certain aspects of summation of
spectator-independent hadronic weak decay widths are given in more detail,
which were not spelled out previously. We also give some useful details of the
1/m_Q expansion in the 't~Hooft model.


title: Flow Equations for Phase Transitions in Statistical Physics and QCD

abstract:
  We review the formalism of the effective average action in quantum field
theory which corresponds to a coarse grained free energy in statistical
mechanics. The associated exact renormalization group equation and possible
nonperturbative approximations for its solution are discussed. We describe in
detail O(N)-symmetric scalar theories in two and three dimensions. These ideas
are also applied to QCD where one observes the consecutive emergence of mesonic
bound states and spontaneous chiral symmetry breaking as the coarse graining
scale is lowered. We finally present a study of the chiral phase transition in
two flavor QCD. A precision estimate of the universal critical equation of
state for the three-dimensional O(4) Heisenberg model is presented. We
explicitly connect the O(4) universal behavior near the critical temperature
and zero quark mass with the physics at zero temperature and a realistic pion
mass. For realistic quark masses the pion correlation length near T_c turns out
to be smaller than its zero temperature value.


title: Measuring WWZ and WWgamma coupling constants with Z-pole data

abstract:
  Triple gauge boson couplings between Z, gamma and the W boson are determined
by exploiting their impact on radiative corrections to fermion-pair production
in e+e- interactions at centre-of-mass energies near the Z-pole. Recent values
of observables in the electroweak part of the Standard model are used to
determine the four parameters epsilon_1, epsilon_2, epsilon_3 and epsilon_b. In
a second step the results on the four epsilon parameters are used to determine
the couplings Delta-g^1_Z and Delta-kappa_gamma. For a wide range of scales,
these indirect coupling measurements are more precise than recent direct
measurements at LEP 2 and at the TEVATRON. The Standard model predictions agree
well with these measurements.


title:
Solution of the off-forward leading logarithmic evolution equation based
  on the Gegenbauer moments inversion

abstract:
  Using the conformal invariance the leading-log evolution of the off-forward
structure function is reduced to the forward evolution described by the
conventional DGLAP equation. The method relies on the fact that the anomalous
dimensions of the Gegenbauer moments of the off-forward distribution are
independent on the asymmetry, or skewedness, parameter and equal to the DGLAP
ones. The integral kernels relating the forward and off-forward functions with
the same Mellin and Gegenbauer moments are presented for arbitrary asymmetry
value.


title: Two-Pion Exchange Interaction Between Constituent Quarks

abstract:
  The two-pion exchange interaction between constituent quarks is shown to
enhance the effect of the the isospin dependent spin-spin component of the
one-pion exchange interaction, and to cancel out its tensor component. It
therefore provides a partial explanation for the phenomenological observation
that the hyperfine interaction between constituent quarks is well described by
a flavor dependent spin-spin interaction, which is attractive at short and
repulsive at long range. The spin-orbit component of the two-pion exchange
interaction is stronger than and has the opposite sign from that associated
with the linear confining interaction in the $P-$shell multiplets.


title:
Hadron Diffractive Processes: the Structure of Soft Pomeron and Colour
  Screening

abstract:
  On the basis of the experimental data on diffractive processes in $\pi p$,
$pp$ and $p \bar p$ collisions at intermediate, moderately high and high
energies, we restore the scattering amplitude related to the $t$-channel
exchange by vacuum quantum numbers by taking account of the diffractive
$s$-channel rescatterings. At intermediate and moderately high energies, the
$t$-channel exchange amplitude turns, with a good accuracy, into an effective
pomeron which renders the results of the additive quark model. At superhigh
energies the scattering amplitude provides a Froissart-type behaviour, with an
asymptotic universality of cross sections such as $\sigma^{tot}_{\pi
p}/\sigma^{tot}_{pp} \to 1$ at $s \to \infty$. The quark structure of hadrons
being taken into account at the level of constituent quarks, the cross sections
of pion and proton (antiproton) in the impact parameter space of quarks,
$\sigma_{\pi}(\vec {r}_{1\perp},\vec {r}_{2\perp};s)$ and $\sigma_p(\vec
{r}_{1\perp},\vec {r}_{2\perp},\vec {r}_{3\perp};s)$, are found as functions of
$s$. These cross sections implicate the phenomenon of colour screening: they
tend to zero at $|\vec r_{i\perp}-\vec r_{k\perp}| \to 0$. The effective colour
screening radius for pion (proton) is found for different $s$. The predictions
for the diffractive cross sections at superhigh energies are presented.


title: Anomalous Higgs Couplings

abstract:
  We review the effects of new effective interactions on the Higgs boson
phenomenology. New physics in the electroweak bosonic sector is expected to
induce additional interactions between the Higgs doublet field and the
electroweak gauge bosons leading to anomalous Higgs couplings as well as to
anomalous gauge-boson self-interactions. Using a linearly realized $SU(2)_L
\times U(1)_Y$ invariant effective Lagrangian to describe the bosonic sector of
the Standard Model, we review the effects of the new effective interactions on
the Higgs boson production rates and decay modes. We summarize the results from
searches for the new Higgs signatures induced by the anomalous interactions in
order to constrain the scale of new physics in particular at CERN LEP and
Fermilab Te vatron colliders.


title: Nucleon Structure Functions in the Three Flavor NJL Soliton Model

abstract:
  We study the relevance of strange degrees of freedom for nucleon structure
functions. For this purpose we employ the three flavor generalization of the
collective quantization approach to the chiral soliton of the bosonized
Nambu-Jona-Lasinio model. Contrary to many other soliton models the hadronic
tensor is tractable in this model. By applying the Bjorken limit to the
hadronic tensor we extract the leading twist contributions to the nucleon
structure functions at the low energy scale at which the model is assumed to
approximate QCD. After transforming to the infinite momentum frame and
performing the DGLAP evolution program to these structure functions we compare
with available data for deep inelastic electron-nucleon scattering.


title: Effects of Extra Space-time Dimensions on the Fermi Constant

abstract:
  Effects of Kaluza-Klein excitations associated with extra dimensions with
large radius compactifications on the Fermi constant are explored. It is shown
that the current precision determinations of the Fermi constant, of the fine
structure constant, and of the W and Z mass put stringent constraints on the
compactification radius. The analysis excludes one extra space time dimension
below $\sim 1.6$ TeV, and excludes 2, 3 and 4 extra space dimensions opening
simultaneously below $\sim$ 3.5 TeV, 5.7 TeV and 7.8 TeV at the $90% CL$.
Implications of these results for future collider experiments are discussed.


title: Soft emissions and the equivalence of BFKL and CCFM final states

abstract:
  This article demonstrates that the BFKL and CCFM equations, despite their
different physical content, lead to equivalent results for any final-state
observable at leading single-logarithmic order. A novel and fundamental element
is the treatment also of the soft (z->1 divergent) part of the splitting
function in the CCFM equation.


title: Singlets and the Electroweak Phase Transition

abstract:
  Singlet extensions of the Standard Model (SM) allow for a strongly first
order electroweak phase transition, because of trilinear terms in the
tree-level potential. We present a systematic procedure to study the parameter
space of the Next-to-Minimal Supersymmetric SM (NMSSM). We find that this model
is consistent with electroweak baryogenesis for a wide range of parameters,
allowing Higgs masses up to at least 115 GeV.


title: Radiative Decays, Nonet Symmetry and SU(3) Breaking

abstract:
  We re-examine the problem of simultaneously describing in a consistent way
all radiative and leptonic decays of light mesons (V -> P gamma, P -> V gamma,
P -> gamma gamma, V -> e^+ e^-). For this purpose, we rely on the Hidden Local
Symmetry model in both its anomalous and non--anomalous sectors. We show that
the SU(3) symmetry breaking scheme proposed by Bando, Kugo and Yamawaki,
supplemented with nonet symmetry breaking in the pseudoscalar sector, allows
one to reach a nice agreement with all data, except for the K^{*+/-} radiative
decay. An extension of this breaking pattern allows one to account for this
particular decay mode too. Considered together, the whole set of radiative
decays provides a pseudoscalar mixing angle theta_P ~ -11^o and a value for
theta_V which is ~ 3^o from that of ideal mixing. We also show that it is
impossible, in a practical sense, to disentangle the effects of nonet symmetry
breaking and those of glue inside the eta', using only light meson decays.


title: Hard-thermal-loop Resummation of the Free Energy of a Hot Gluon Plasma

abstract:
  We calculate the free energy of a hot gluon plasma to leading order in
hard-thermal-loop perturbation theory. Effects associated with screening, gluon
quasiparticles, and Landau damping are resummed to all orders. The ultraviolet
divergences generated by the hard-thermal-loop propagator corrections can be
cancelled by a temperature-independent counterterm. The deviation of the
hard-thermal-loop free energy from lattice QCD results for T > 2 T_c has the
correct sign and roughly the correct magnitude to be accounted for by
next-to-leading order corrections.


title: Recent Progress in Electroweak Baryogenesis

abstract:
  The status of electroweak baryogenesis in the minimal supersymmetric standard
model is reviewed. I discuss the strength of the phase transition, CP violation
and transport at the bubble walls, and the possibility of a two stage
transition involving charge and color breaking.


title: On the Chiral Quark Soliton Model with Pauli-Villars Regularization

abstract:
  The Pauli-Villars regularization scheme is often used for evaluating parton
distributions within the framework of the chiral quark soliton model with
inclusion of the vacuum polarization effects. Its simplest version with a
single subtraction term should however be taken with some caution, since it
does not fully get rid of divergences contained in scalar and psuedoscalar
quark densities appearing in the soliton equation of motion. To remedy this
shortcoming, we propose here its natural extention, i.e. the Pauli-Villars
regularization scheme with multi-subtraction terms. We also carry out a
comparative analysis of the Pauli-Villars regularization scheme and more
popular proper-time one. It turns out that some isovector observables like the
isovector magnetic moment of the nucleon is rather sensitive to the choice of
the regularization scheme. In the process of tracing the origin of this
sensitivity, a noticeable difference of the two regularization scheme is
revealed.


title: Singularity in Potential, Perturbation and Variational Methods

abstract:
  In this work, we carefully study the energy eigen-values and splitting of
heavy quarkonia as there exist $1/r^3$ and $\delta^3(\vec r)$ singular terms in
the potential which make a direct numerical solution of the Schr\"{o}dinger
equation impossible. We compare the results obtained in terms of perturbation
and variational methods with various treatments.


title:
Beyond HTL: The Classical Kinetic Theory of Landau Damping for
  Selfinteracting Scalar Fields in the Broken Phase

abstract:
  The effective theory of low frequency fluctuations of selfinteracting scalar
fields is constructed in the broken symmetry phase. The theory resulting from
integrating fluctuations with frequencies much above the spontanously generated
mass scale $(p_0>>M)$ is found to be local. Non-local dynamics, especially
Landau damping emerges under the effect of fluctuations in the $p_0 \sim M$
region. A kinetic theory of relativistic scalar gas particles interacting via
their locally variable mass with the low frequency scalar field is shown to be
equivalent to this effective field theory for scales below the characteristic
mass, that is beyond the accuracy of the Hard Thermal Loop (HTL) approximation.


title: Precision Electroweak Measurements and ``New Physics''

abstract:
  The status of several precisely measured electroweak parameters is reviewed.
Natural relations among them are shown to constrain the Higgs mass, m_H, as
well as various ``New Physics'' effects. Indications of an anomalous Zb anti-b
coupling are discussed. Constraints on excited W^* bosons are given.


title: Radiative corrections to W-pair mediated four-fermion production at LEP2

abstract:
  We present the radiative corrections to off-shell $W$-pair production, as
calculated within the double-pole approximation.


title:
New Analysis of the Delta I = 1/2 Rule in Kaon Decays and the B_K
  Parameter

abstract:
  We present a new analysis of the Delta I = 1/2 rule in K --> pi pi decays and
the B_K parameter. We use the 1/N_c expansion within the effective chiral
lagrangian for pseudoscalar mesons and compute the hadronic matrix elements at
leading and next-to-leading order in the chiral and the 1/N_c expansions.
Numerically, our calculation reproduces the dominant Delta I = 1/2 K --> pi pi
amplitude. Our result depends only moderately on the choice of the cutoff scale
in the chiral loops. The Delta I = 3/2 amplitude emerges sufficiently
suppressed but shows a significant dependence on the cutoff. The B_K parameter
turns out to be smaller than the value previously obtained in the 1/N_c
approach. It also shows a significant dependence on the choice of the cutoff
scale. Our results indicate that corrections from higher order terms and/or
higher resonances are large for the Delta I = 3/2 K --> pi pi amplitude and the
(|Delta S| = 2) K^0 -- anti K^0 transition amplitude.


title: Nonperturbative QCD vacuum and Colour Superconductivity

abstract:
  We discuss the possibility of existence of colour superconducting state in
real QCD vacuum with nonzero gluon condensate. We argue, that nonperturbative
gluonic fields might play a crucial role in colour superconductivity scenario.


title: Ab Initio Study of Hybrid b-bar-gb Mesons

abstract:
  Hybrid b-bar-gb molecules in which the heavy b-bar-b pair is bound together
by the excited gluon field g are studied using the Born-Oppenheimer expansion
and numerical simulations. The consistency of results from the two approaches
reveals a simple and compelling physical picture for heavy hybrid states.


title:
Modelling J/psi production and absorption in a microscopic
  nonequilibrium approach

abstract:
  Charmonium production and absorption in heavy ion collisions is studied with
the Ultrarelativisitic Quantum Molecular Dynamics model. We compare the
scenario of universal and time independent color-octet dissociation cross
sections with one of distinct color-singlet J/psi, psi' and chi_c states,
evolving from small, color transparent configurations to their asymptotic
sizes. The measured J/psi production cross sections in pA and AB collisions at
SPS energies are consistent with both - purely hadronic - scenarios. The
predicted rapidity dependence of J/psi suppression can be used to discriminate
between the two experimentally. The importance of interactions with secondary
hadrons and the applicability of thermal reaction kinetics to J/psi absorption
are investigated. We discuss the effect of nuclear stopping and the role of
leading hadrons. The dependence of the psi' to J/psi ratio on the model
assumptions and the possible influence of refeeding processes is also studied.


title: Photoproduction of $\eta_c$ in NRQCD

abstract:
  We present a calculation for the photoproduction of $\eta_c$ under the
framework of NRQCD factorization formalism. We find a quite unique feature that
the color-singlet contribution to this process vanishes at not only the leading
order but also the next to leading order perturbative QCD calculations and that
the dominant contribution comes from the color-octet ${}^1S_0^{(8)}$
subprocess. The nonperturbative color-octet matrix element of ${}^1S_0^{(8)}$
of $\eta_c$ is related to that of ${}^3S_1^{(8)}$ of $J/\psi$ by the heavy
quark spin symmetry, and the latter can be determined from the direct
production of $J/\psi$ at large transverse momentum at the Fermilib Tevatron.
We then conclude that the measurement of this process may clarify the existing
conflict between the color-octet prediction and the experimental result on the
$J/\psi$ photoprodution.


title: A Review on Neutrino Physics, Mass and Oscillations

abstract:
  We present a short review of the present status of the problem of neutrino
masses and mixing including a survey of theoretical motivations and models,
experimental searches and implications of recently appeared solar and
atmospheric neutrino data, which strongly indicate nonzero neutrino masses.
Such data apparently requires the existence of light sterile neutrino in
addition to the three active ones and two-generation nearly maximal mixing.


title: Complete Lagrangian of MSSM

abstract:
  A brief derivation of the lagrangian of the minimal supersymmetric theory is
given and the complete expression of the lagrangian in terms of mass
eigenstates is presented.


title: Power corrections to event shapes and factorization

abstract:
  We study power corrections to the differential thrust, heavy mass and related
event shape distributions in $e^+e^-$-annihilation, whose values, $e$, are
proportional to jet masses in the two-jet limit, $e\to 0$. The factorization
properties of these differential distributions imply that they may be written
as convolutions of nonperturbative "shape" functions, describing the emission
of soft quanta by the jets, and resummed perturbative cross sections. The
infrared shape functions are different for different event shapes, and depend
on a factorization scale, but are independent of the center-of-mass energy $Q$.
They organize all power corrections of the form $1/(eQ)^n$, for arbitrary $n$,
and carry information on a class of universal matrix elements of the
energy-momentum tensor in QCD, directly related to the energy-energy
correlations.


title: Universal pion freeze-out phase-space density

abstract:
  Results on the pion phase-space density at freeze-out in sulphur-nucleus,
Pb-Pb and pi-p collisions at the CERN SPS are presented. All heavy-ion
reactions are consistent with the thermal Bose-Einstein distribution
f=1/[exp(E/T)-1] at T ~ 120 MeV, modified for radial expansion. pi-p data are
also consistent with f, but at T ~ 180 MeV and without radial flow.


title:
Screened-Coulomb ansatz for the non-factorizable radiative corrections
  to the off-shell W^+ W^- production

abstract:
  We demonstrate that the results of the complete first order calculation of
the non-factorizable QED corrections to the single-inclusive cross-sections for
$e^+e^- \to W^+W^- \to 4$ fermions could be very well reproduced by a simple
physically motivated ansatz. The latter allows to take into account effectively
the screening role of the non-Coulomb radiative mechanisms by introducing a
dampening factor in front of the width-dependent part of the known first-order
Coulomb correction, the so-called screened-Coulomb ansatz.


title: Nonequilibrium chiral perturbation theory

abstract:
  We explore the extension of chiral perturbation theory out of thermal
equilibrium. The pion decay constant becomes then a time-dependent function and
we work within the Schwinger-Keldysh contour technique. A useful connection
with curved space-time QFT allows to renormalise the model. We discuss the
applicability of our approach within a relativistic heavy-ion collision
environment.


title:
Probing Relativistic Spin Effects in the Nucleon by Means of Drell-Yan
  Processes

abstract:
  Significant differences between transverse and longitudinal polarized parton
distributions are found at low energies within a light-front covariant quark
model of the nucleon. These differences are due to relativistic spin effects
introduced by the Melosh rotations and survive evolution to higher $Q^2$
scales. A specific observable related to double-spin asymmetries in lepton pair
production in polarized hadron-hadron collisions is defined. The possibility of
assessing the relevance of these relativistic spin effects in future
experiments at RHIC and HERA--$\vec{N}$ is discussed.


title:
BS and DS equations in a Wilson loop context in QCD, effective mass
  operator, q-qbar spectrum

abstract:
  We briefly discuss the quark-antiquark Bethe-Salpeter equation and the quark
Dyson-Schwinger equation derived in preceding papers. We also consider the
q-qbar quadratic mass operator M^{2} = (w_{1} + w_{2})^{2} + U obtained by
three-dimensional reduction of the BS equation and the related approximate
center of mass Hamiltonian or linear mass operator H_{CM} = M = w_{1} + w_{2} +
V + ... We revue previous results on the spectrum and the Regge trajectories
obtained by an approximate diagonalization of H_{CM} and report new results
similarly obtained by an approximate diagonalization of H_{CM} and report new
results similarly obtained for the original M^{2}. We show that in both cases
we succeed to reproduce fairly well the entire meson spectrum in the cases in
which the numerical calculations were actually practicable and with the
exception of the light pseudoscalar states (related to the chiral symmetry
problematic). A small rearrangement of the parameters and the use of a running
coupling constant is necessary in the M^{2} case.


title: Hide and Seek with Supersymmetry

abstract:
  This is the summary of a 90 minute introductory lecture on Supersymmetry
presented at the Swiss Summer School on ``Hidden Symmetries and Higgs
Phenomena'' at Zuoz, Engadin, in August 1998. I first review the hierarchy
problem, and then discuss why we expect supersymmetry just around the corner,
i.e. at or below $1\tev$. I focus on the specific example of the anomalous
magnetic moment of the muon to show how supersymmetry can indeed hide just
around the corner without already having been detected. An essential part of
supersymmetry's disguise is the fact that it is broken. I end by briefly
outlining how the disguise itself is also hidden.


title: Disentangling violations of CPT from other new-physics effects

abstract:
  We analyze the prospects for observing CPT violation using neutral-meson
P0-P0bar systems. Before one can claim a measurement of CPT violation, one must
be able to rule out the possibility that its result is due to simpler
new-physics effects. In particular, one must be able to separate the
CPT-violating quantities from parameters violating the Delta P = \Delta Q rule
of semileptonic decays, and from new-physics contributions to the production
mechanism of the neutral mesons. One can isolate CPT violation using the
semileptonic decays of single, tagged neutral mesons; unfortunately, this
situation cannot be implemented at the Upsilon(4S). For P0-P0bar pairs produced
in a correlated parity-odd state we show that, by combining the di-lepton with
the single-lepton decays, it is in principle possible to extract unambiguously
one CPT-violating parameter. Finally, we develop the formalism necessary for
describing new-physics effects in the production mechanism; this includes both
cascade decays and violations of the rule of associated production.


title: The omega to rho pi transition and omega to rho 3 pi decay

abstract:
  We evaluate the omega to rho pi transition and the omega to 3 pi decay using
a Quark Level Linear Sigma Model ($QL\sigma M$). We obtain $g^{QL\sigma
M}_{\omega\rho\pi}= (10.33 - 14.75) GeV^{-1}$ to be compared with other model
dependent estimates averaging to $g_{\omega\rho\pi} = 16 GeV^{-1}$. We show
that in the $QL\sigma M$ a contact term is generated for the $\omega \to 3 \pi$
decay. Although the contact contribution by itself is small, the interference
effects turn out to be important.


title:
Associated Production of Gauginos and Gluinos at Hadron Colliders in
  Next-to-Leading Order SUSY-QCD

abstract:
  We report a next-to-leading order (NLO) calculation of the production of
gaugino-like charginos ($\chargino$) and neutralinos ($\neutralino$) in
association with gluinos ($\gluino$) at hadron colliders, including the strong
corrections from colored particles and sparticles. We predict inclusive cross
sections at the Fermilab Tevatron and CERN LHC. The NLO cross sections are more
stable against variations in the hard-scattering scale parameter and are
greater than the LO values.


title: The role of resonances in non-leptonic hyperon decays

abstract:
  We examine the importance of resonances for the non-leptonic hyperon decays
in the framework of chiral perturbation theory. Lower lying resonances are
included into the effective theory. Integrating out the heavy degrees of
freedom in the resonance saturation scheme generates higher order counterterms
in the effective Lagrangian, providing an estimate of the pertinent coupling
constants. A fit to the eight independent decay amplitudes that are not related
by isospin symmetry is performed and reasonable agreement for both s- and p-
waves is achieved.


title: Higgsinos in SUSY Models with Gaugino Mass Unification

abstract:
  In the MSSM, the assumptions of a common sfermion mass parameter m_0 and a
common gaugino mass parameter m_1/2, along with the requirements from radiative
electroweak symmetry breaking, lead to relatively large values of the Higgs
mixing parameter mu, and consequently to a gaugino-like lightest neutralino.
Lifting the requirement that the Higgs mass parameters unify with the sfermion
masses is known to allow for smaller mu. We show that a mu parameter
sufficiently small to yield a Higgsino-like neutralino requires a precise
adjustment of the Higgs mass parameter m_Hu. Consequently a gaugino-type
neutralino is still preferred in SUSY models with gaugino mass unification.


title: Comments on CPT tests

abstract:
  What do we know about CPT symmetry? We conclude that the direcrt measurement
of CPT violation leads to a result that CPT violation force is limited to about
30% of CP violating forces. The best test of CPT symmetry is to see if
theoretical prediction for the phase of eta_{+-} and eta_{00} agree with
experiments. We discuss uncertainties associated with this prediction, and how
to improve it. A new test of CPT is also discussed.


title:
Highest-energy cosmic rays from Fermi-degenerate relic neutrinos
  consistent with Super-Kamiokande results

abstract:
  Relic neutrinos with mass 0.07 (+0.02/-0.04) eV, in the range consistent with
Super-Kamiokande data, can explain the cosmic rays with energies in excess of
the Greisen-Zatsepin-Kuzmin cutoff. The spectrum of ultra-high energy cosmic
rays produced in this fashion has some distinctive features that may help
identify their origin. Our mechanism does not require but is consistent with a
neutrino density high enough to be a new kind of hot dark matter.


title:
\tau Polarization asymmetry in $B \to X_s \tau^+ \tau^-$ in SUSY models
  with large $tan\beta$

abstract:
  Rare B decays provides an opportunity to probe for new physics beyond the
standard model. the effective Hamiltonian for the decay $b \to s l^+ l^-$
predicts the characteristic polarization for the final state lepton. Lepton
polarization has, in addition to a longitudinal component $P_L$, two orthogonal
components $P_T$ and $P_N$ lying in and perpendicular to the decay plane. In
this article we perform a study of the $\tau$-polarisation asymmetry in the
case of SUSY models with large $\tan\beta$ in the inclusive decay $B \to X_s
\tau^+ \tau^-$.


title:
Spin Effects in Diffractive $J/\Psi$ Leptoproduction and Structure of
  Pomeron Coupling

abstract:
  We calculate the cross section and the $A_{ll}$ asymmetry of the diffractive
vector meson leptoproduction for a simple model of the pomeron coupling with
the proton. It is found that the sensitivity of the spin--dependent cross
section of the diffractive $J/\Psi$ production to the pomeron coupling
structure is rather weak. The conclusion is made that it will be difficult to
study the structure of the pomeron coupling with the proton in future polarized
diffractive experiments on the $J/\Psi$ production.


title: The action of neutrino ponderomotive force on supernova dynamics

abstract:
  Collective interactions of a beam of neutrinos/antineutrinos traversing a
dense magnetized plasma of electrons/positrons, protons and neutrons are
studied with particular reference to the case of a Supernova. We find that the
ponderomotive force exerted by neutrinos gives, contrary to expectations, a
negligible contribution to the revival of the shock for a successful Supernova
explosion, although new types of convection and plasma cooling processes
induced by the ponderomotive force could be, in principle, relevant for the
dynamics itself.


title: Exact Parametrization of Majorana Neutrino Mass Matrix with Large Mixing

abstract:
  Under the assumption that the neutrinos are Majorana particles we study how
the lepton mass matrices can be transformed into the simple form which has the
same physical quantities by removing redundant parameters. We propose the exact
parametrization of the lepton mass matrices which reflects the small nu_e-nu_mu
mixing and the large nu_mu-nu_tau mixing. The relations between the twelve
parameters and the physical quantities are shown. Furthermore we calculate the
MNS matrix by applying the assumptions used in the quark sector. Finally we
also check the validity of these assumptions from the experimental values.


title:
Pomeron in diffractive processes $\gamma^*(Q^2)p\to\rho^0 p$ and
  $\gamma^*(Q^2)p\to\gamma^*(Q^2) p$ at large Q^2: the onset of pQCD

abstract:
  We study the reactions $\gamma^*(Q^2)p\to\rho^0 p$ and
$\gamma^*(Q^2)p\to\gamma^*(Q^2) p$ at large Q^2 and $W^2/Q^2$ and small
momentum transfer, $\kappa^2_\perp$, to the nucleon where the pomeron exchange
dominates. At large Q^2 the virtual photon selects a hard $q\bar q$ pair, thus
selecting the hard pomeron component (the BFKL pomeron). The amplitudes for
both transverse and longitudinal polarizations of the initial photon and
outgoing $\rho$-meson (photon) are calculated in the framework of the BFKL
pomeron exchange. Our calculations show that one cannot expect the early onset
of the pure perturbative regime in the discussed diffractive processes: the
small interquark distances, $\rho_{q\bar q} <0.2$ fm, start to dominate not
earlier than at $Q^2 \simeq 100 GeV^2, W^2/Q^2 \simeq 10^7$ in
$\gamma^*(Q^2)p\to\rho^0 p$ and $Q^2 \simeq 50 GeV^2, W^2/Q^2 \simeq 10^6$ in
$\gamma^*(Q^2)p\to\gamma^*(Q^2) p$.


title: Quarkonium in the Wilson loop formalism: new perspectives

abstract:
  We review the present knowledge on the heavy quark interaction. The framework
is the NRQCD effective theory and the interaction is expressed in terms of
Wilson loop chromoelectric and chromomagnetic insertions.


title: Fine structure of spectrum of twist-three operators in QCD

abstract:
  We unravel the structure of the spectrum of the anomalous dimensions of the
quark-gluon twist-3 operators which are responsible for the multiparton
correlations in hadrons and enter as a leading contribution to several physical
cross sections. The method of analysis is bases on the recent finding of a
non-trivial integral of motion for the corresponding Hamiltonian problem in
multicolour limit which results into exact integrability of the three-particle
system. Quasiclassical expansion is used for solving the problem. We address
the chiral-odd sector as a case of study.


title:
Looking for anomalous gamma-gamma-H and Z-gamma-H couplings at future
  linear collider

abstract:
  We consider the possibility of studying anomalous contributions to the
gamma-gamma-H and Z-gamma-H vertices through the process e-gamma--> e-H at
future e-gamma linear colliders, with Sqrt(S)=500-1500 GeV. We make a model
independent analysis based on SU(2)xU(1) invariant effective operators of dim=6
added to the standard model lagrangian. We consider a light Higgs boson (mostly
decaying in bar(b)-b pairs), and include all the relevant backgrounds. Initial
e-beam polarization effects are also analyzed. We find that the process
e-gamma--> e-H provides an excellent opportunity to strongly constrain both the
CP-even and the CP-odd anomalous contributions to the gamma-gamma-H and
Z-gamma-H vertices.


title: Critical Slowing Down and Defect Formation

abstract:
  The formation of topological defects in a second order phase transition in
the early universe is an out-of-equilibrium process. Condensed matter
experiments seem to support Zurek's mechanism, in which the freezing of thermal
fluctuations close to the critical point (critical slowing down) plays a
crucial role. We discuss how this picture can be extrapolated to the early
universe, pointing out that new scaling laws may emerge at very high
temperatures and showing how critical slowing down emerges in the context of a
relativistic quantum field theory.


title:
Leptogenesis in the Light of Super-Kamiokande Data and a Realistic
  String Model

abstract:
  We discuss leptogenesis in the light of indications of neutrino masses and
mixings from Super-Kamiokande and other data on atmospheric neutrinos, as well
as the solar neutrino deficit. Neutrino masses and mixings consistent with
these data may produce in a natural and generic way a lepton asymmetry that is
suffient to provide the observed baryon asymmetry, after processing via
non-perturbative electroweak effects. We illustrate this discussion in the
framework of the string-derived flipped SU(5) model, using particle assignments
and choices of vacuum parameters that are known to give realistic masses to
quarks and charged leptons. We display one scenario for neutrino masses that
also accommodates leptogenesis.


title: Hadron Freeze-out and QGP Hadronization

abstract:
  Abundances and $m_\bot$-spectra of strange and other hadronic particles
emanating from central 158-200 A GeV reactions between nuclei are found to
originate from a thermally equilibrated, deconfined source in chemical
non-equilibrium. Physical freeze-out parameters and physical conditions
(pressure, specific energy, entropy, and strangeness) are evaluated. Five
properties of the source we obtain are as expected for direct hadron emission
(hadronization) from a deconfined quark-gluon plasma phase.


title:
Bound state in the vector channel of the extended Nambu--Jona-Lasinio
  model at fixed f_\pi

abstract:
  We show that, as a consequence of fixing f_\pi = 93 MeV: (1) a bound state
pole in the J^P = 1^- scattering amplitude of the ENJL model exists for
arbitrarily weak (positive) vector coupling G_2 so long as the constituent
quark mass is sufficiently large; (2) there is a bound state for any quark mass
when G_2 \geq 0.6/(8 f_\pi^2); (3) this bound state becomes massless at G_2 =
1/(8 f_\pi^2) and a tachyon for G_2 exceeding it. We show by way of an example
that the model has no trouble fitting the \rho meson mass simultaneously with
other observables.


title:
The Nambu-Jona Lasinio mechanism and the electroweak symmetry breaking
  in the Standard Model

abstract:
  This is a short report of the entire work developed during the study of the
possible realizations of the "Top Mode" Standard Model. Here it is examined the
breaking of internal symmetries from another point of view showing that is
possible to reproduce the gauged electroweak panorama of the traditional
Standard Model in a exhaustive and selfconsistent way. The result is reached
applying the main futures of the Nambu-Jona Lasinio (NJL) mechanism to an
electroweak invariant Lagrangian. In this context the use of functional
formalism for composite operators naturally leads to a different dynamical
approach. Meanwhile the Higgs mechanism acts on the Lagrangian form, a NJL like
model looks directly at the physics of the system showing the real dynamical
content hidden in the Green functions of the theory.


title:
String Unification at Intermediate Energies: Phenomenological Viability
  and Implications

abstract:
  Motivated by the fact that the string scale can be many orders of magnitude
lower than the Planck mass, we investigate the required modifications in the
MSSM $\beta$--functions in order to achieve intermediate ($10^{10-13}$GeV)
scale unification, keeping the traditional logarithmic running of the gauge
couplings. We present examples of string unified models with the required extra
matter for such a unification while we also check whether other MSSM properties
(such as radiative symmetry breaking) are still applicable.


title: B^+ --> D^{*+}_s gamma and B^+ --> D^{*+} gamma as Probes of V_{ub}

abstract:
  The decays B^+ --> D^{*+}_s gamma and B^+ --> D^{*+} gamma can be used for an
extraction of |V_{ub}|. When the b and c quarks are nearly degenerate the rate
for these modes can be determined in terms of other observed rates, namely
B\bar{B} mixing and D^* --> D gamma decay. To this end we introduce a novel
application of heavy quark and flavor symmetries. Although somewhat
unrealistic, this limit provides us with a first estimate of these rates.


title: Wigner symmetry in the limit of large scattering lengths

abstract:
  We note that in the limit where the NN 1S0 and 3S1 scattering lengths,
a^(1S0) and a^(3S1), go to infinity, the leading terms in the effective field
theory for strong NN interactions are invariant under Wigner's SU(4)
spin-isospin symmetry. This explains why the leading effects of radiation pions
on the S-wave NN scattering amplitudes vanish as a^(1S0) and a^(3S1) go to
infinity. The implications of Wigner symmetry for NN to NN axion and gamma d to
n p are also considered.


title:
Higgs Bosons in the Minimal Supersymmetric Standard Model with Explicit
  CP Violation

abstract:
  We study the Higgs-boson mass spectrum of the minimal supersymmetric standard
model, in which the tree-level CP invariance of the Higgs potential is broken
explicitly by loop effects of soft-CP-violating Yukawa interactions related to
scalar quarks of the third generation. The analysis is performed by considering
the CP-non-invariant renormalization-group improved effective potential through
next-to-leading order that includes leading logarithms due to two-loop Yukawa
and QCD corrections. We find that the three neutral Higgs particles predicted
by the theory may strongly mix with one another, thereby significantly
modifying their tree-level couplings to fermions and to the $W^\pm$ and Z
bosons. We analyze the phenomenological consequences of such a minimal
supersymmetric scenario of explicit CP violation on the production rates of the
lightest Higgs particle, and discuss strategies for its potential discovery at
high-energy colliders.


title: Parton Distributions for the Octet and Decuplet Baryons

abstract:
  We calculate the parton distributions for both polarized and unpolarized
octet and decuplet baryons, using the MIT bag, dressed by mesons. We show that
the hyperfine interaction responsible for the $\Delta - N$ and $\Sigma^0 -
\Lambda$ splittings leads to large deviations from SU(3) and SU(6) predictions.
For the $\Lambda$ we find significant polarized, non-strange parton
distributions which lead to a sizable $\Lambda$ polarization in polarized,
semi-inclusive $ep$ scattering. We also discuss the flavour symmetry violation
arising from the meson-cloud associated with the chiral structure of baryons.


title:
Screening Masses of Hot SU(2) Gauge Theory from the 3D Adjoint Higgs
  Model

abstract:
  We study the Landau gauge propagators of the lattice SU(2) 3d adjoint Higgs
model, considered as an effective theory of high temperature 4d SU(2) gauge
theory. From the long distance behaviour of the propagators we extract the
screening masses. It is shown that the pole masses extracted from the
propagators agree well with the screening masses obtained recently in finite
temperature SU(2) theory. The relation of the propagator masses to the masses
extracted from gauge invariant correlators is also discussed. In so-called
lambda gauges non-perturbative evidence is given for the gauge independence of
pole masses within this class of gauges.


title: New Formulas and Predictions for Running Masses at Higher Scales in MSSM

abstract:
  Including contributions of scale-dependent vacuum expectation values of Higgs
scalars, we derive new one-loop formulas analytically for running quark-lepton
masses at higher scales in MSSM. Apart from the gauge-coupling dependence being
different from earlier formulas, the third-generation- Yukawa-coupling effects
are absent in the masses of the first two generations. While predicting the
masses and $\tan\beta$ numerically, we also include two-loop effects.


title: Baryon Distribution Amplitudes in QCD

abstract:
  We develop a new theoretical framework for the description of leading twist
light-cone baryon distribution amplitudes which is based on integrability of
the helicity $\lambda=3/2$ evolution equation to leading logarithmic accuracy.
A physical interpretation is that one can identify a new `hidden' quantum
number which distinguishes components in the $\lambda=3/2$ distribution
amplitudes with different scale dependence. The solution of the corresponding
evolution equation is reduced to a simple three-term recurrence relation. The
exact analytic solution is found for the component with the lowest anomalous
dimension for all moments $N$, and the WKB-type expansion is constructed for
other levels, which becomes asymptotically exact at large $N$. Evolution
equations for the $\lambda=1/2$ distribution amplitudes (e.g. for the nucleon)
are studied as well. We find that the two lowest anomalous dimensions for the
$\lambda=1/2$ operators (one for each parity) are separated from the rest of
the spectrum by a finite `mass gap'. These special states can be interpreted as
scalar diquarks.


title: Static mass scales in hot gauge theories

abstract:
  The static sectors of the electroweak Standard Model and QCD at finite
temperatures are described by 3d SU(N) Higgs models with scalars in the
fundamental and adjoint representation, respectively. I summarize the
non-perturbative physics of these theories like mass spectrum, string tension,
screening of the static potential and non-perturbative corrections to the Debye
mass, as obtained from recent lattice simulations. It is observed that in the
3d theory corresponding to the purely magnetic sector there is a larger
hierarchy between different quantities than between the electric ($\sim gT$)
and magnetic ($\sim g^2T$) sectors of finite T gauge theories, which are not
generally well separated.


title: Soft-QCD Effects In B to gamma gamma Decay: Quark Level Form Factors

abstract:
  Soft-QCD effects of quark-level form factors in $\gamma\gamma$ decay of
$B_s$-mesons via $D{\bar D}$ intermediate states, suggested by Ellis et al, are
examined in the "Salpeter" model [reinterpreted in terms of the Markov-Yukawa
Transversality Principle (MYTP)] when formulated on a covariant light front
(null-plane). The gluonic kernel in the infrared regime which generates the
constituent mass via standard $DB{\chi}S$, is calibrated to both $q{\bar q}$
and qqq spectra, meson mass splittings, pion form factor,and other parameters.
With this check, an exact evaluation of the $D{\bar D}\gamma$ vertex form
factor $F(\alpha)$ (normalized to F(0)=1), gives a multiplicative effect of
$F^2(\alpha)$ on the $B_s \Rightarrow \gamma\gamma$ amplitude via D-meson
triangle loop, where $\alpha$ = $(p^2+M^2)/M^2$ is the off-shellness parameter
of the exchanged D-meson of mass M and 4-momentum $p_\mu$, and is a variables
of the (internal)loop integration. Unfortunately, the $F^2(\alpha)$ effect
decreases the loop amplitude by a factor of 30 w.r.t. the point hadron value,
resulting in a reduction of 3 orders of magnitude in long distance (hadronic)
contributions to the $B_s \Rightarrow \gamma\gamma$ decay rate, thus greatly
impairing the visibility of such modes. PACS: 11.10.St ; 12.38.Lg ; 13.20.Gd ;
13.40.Hq Keywords: $B_s$ radiative decay; Soft-QCD; Vertex-Fn; Form-factor;
Markov-Yukawa-Transversality Principle; Salpeter eq; Cov. light front


title: Charmless Hadronic Two-Body Decays of B Mesons

abstract:
  A way of circumventing the gauge and infrared problems with effective Wilson
coefficients is shown. Implications of experimentally measured charmless $B$
decays are discussed.


title: Gluon Correlation Moments Ratio in the Instanton Field

abstract:
  The instanton-induced multiple events in high energy collisions are
considered in nonperturbative quantum chromodynamics. Here we obtained unusual
behaviour of ratio of correlation moments Hq for such processes which can be
used for experimental search of instantons.


title: Can unstable relics save pure Cold Dark Matter?

abstract:
  The standard CDM model fails to describe the power spectrum of fluctuations
since it gives too much power at small scales. Among other possible
improvements, it has been suggested that an agreement with observations can be
achieved with the addition of a late decaying particle, through the injection
of non-thermal radiation and the consequent increase of the horizon length at
the equivalence time. We analyze the possibility of implementing this idea in
some extensions of the electroweak standard model, discussing the cosmological
and astrophysical bounds to which these schemes are subject.


title: Extra Dimensions and Inflation

abstract:
  It has been proposed that, without invoking supersymmetry, it is possible to
solve the hierarchy problem provided the fundamental scale in the higher
dimensional theory is at a much lower scale than the Planck scale. In this
paper we consider a toy model where we allow $4+d$ dimensions to evolve from a
region determined by the new fundamental scale, which is in our case is
electro-weak scale. We further investigate whether it is possible to inflate
not only the 3 uncompactified dimensions but also the extra dimensions. We
require around 70 e-foldings to stabilize the size of two extra dimensions from
$M_{\rm EW}^{-1}$ to the required 1 mm size. This can be easily achieved during
inflation, but once inflation ends their evolution is governed by the dynamical
history of the universe in a similar way that of Brans-Dicke field in
generalized Einstein theories. We also show that we achieve the right level of
density contrast without invoking any specific potential. The density contrast
depends on the number of extra dimensions and upon the amplitude of the
potential.


title: Large and Fun CP Violation in B Meson Decays: Where to Search?

abstract:
  The best place to search for direct CP violation is the already observed
charmless $b\to s$ modes. In SM with FSI, $a_{CP}$ in $K\pi$ modes could be as
large as 20-30% but differ in sign between $K^-\pi^+/K^-\pi^0$ and $\bar K^0
\pi^-$. We illustrate possible New Physics effects that could lead to $a_{CP}$
of order 40-60% in $K\pi$ and $\phi K$ modes distinguishable from FSI. $b\to
s\gamma$ modes can also exhibit interesting asymmetries.


title: High Energy Astrophysical Neutrinos: the Upper Bound is Robust

abstract:
  We elucidate the physical basis for the upper bound on high energy neutrino
fluxes implied by the observed cosmic ray flux. We stress that the bound is
valid for neutrinos produced either by p,gamma reactions or by p-p(n) reactions
in sources which are optically thin for high energy protons to photo-meson and
nucleon-meson interactions. We show that the upper bound is robust and
conservative. The Waxman-Bahcall bound overestimates the most likely neutrino
flux by a factor ~ 5/tau, for small optical depths tau. The upper limit cannot
be plausibly evaded by invoking magnetic fields, optically thick AGNs, or large
hidden fluxes of extragalactic protons. We describe the implications of the
bound for future experiments including the AMANDA, ANTARES, Auger, ICECUBE,
NESTOR, and OWL/AIRWATCH detectors.


title: A_{LT} in the Nucleon-Nucleon Polarized Drell-Yan Process

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


title: Lepton and Quark Mass Matrices

abstract:
  We propose a model that all quark and lepton mass matrices have the same zero
texture. Namely their (1,1), (1,3) and (3,1) components are zeros. The mass
matrices are classified into two types I and II. Type I is consistent with the
experimental data in quark sector. For lepton sector, if seesaw mechanism is
not used, Type II allows a large $\nu_\mu - \nu_\tau$ mixing angle. However,
severe compatibility with all neutrino oscillation experiments forces us to use
the seesaw mechanism. If we adopt the seesaw mechanism, it turns out that Type
I instead of II can be consistent with experimental data in the lepton sector
too.


title: Conditions for Nuclear-Matter Lasers

abstract:
  Conditions are analysed when in dense and hot nuclear matter large amounts of
Bose particles can be created. An intensive production of Bose particles is the
main necessary condition for realizing their coherent emission similar to
radiation from photon lasers. The consideration is based on the multichannel
model of nuclear matter. Analysis shows that possible candidates for
nuclear--matter lasing are mesons (mainly pions), dibaryons, and gluons.


title:
Baryon Resonances in the Double Pion Channel at Jefferson Lab (CEBAF):
  Experimental and Physical Analysis Status and Perspectives

abstract:
  Decay of light quark excited baryons in the double pion channel is discussed,
as a particular way of investigating poorly know baryon resonances and
searching for "missing states" predicted by quark models. A possible approach
to the data analysis is discussed and some preliminary data from the CLAS
collaboration at Jefferson Laboratory are presented.


title: Calculation of density fluctuation in inflationary epoch

abstract:
  Starting from an initial state of thermal equilibrium, we derive an
expression for the quantum fluctuation in the energy density during the
inflationary epoch in terms of the mode functions for the inflaton field. The
effect of this particular initial state is not washed out in the final formula,
contrary to what is usually believed. Numerically, however, the effect is
completely negligible, validating the use of the two point function in the
vacuum state. We also point out the requirement of conventional quantum field
theory during inflation, that the quantum fluctuation in a wavelength must be
evaluated, at the latest, when the wavelength crosses the Hubble length, in
contrast to the usual practice in the literature.


title:
The relevance of the vertex bremsstrahlung photon detection in the
  electron-neutrino (antineutrino) electron scattering experiments at low
  energy

abstract:
  We discuss the size of the electron-antineutrino electron into
electron-antineutrino electron cross section reduction due to the rejection of
the events with a vertex bremsstrahlung photon above a certain energy in the
final state. In particular we analyze the effect in experiments designed to
detect the low energy electron-antineutrino and electron-neutrino from a
nuclear reactor and from the Sun. We find that such reduction has to be
considered in a relatively high statistic reactor experiment, while it is
negligible for pp and 7Be solar neutrino detection.


title: Nucleon Structure Functions in a Chiral Soliton Model

abstract:
  The computation of nucleon structure functions within the Nambu-Jona-Lasinio
chiral soliton model is outlined. After some technical remarks on the issue of
regularization numerical results for the both unpolarized and polarized
structure functions are presented. The generalization to flavor SU(3) is
sketched.


title:
Strong Interaction Effects in Stop Pair Production at $e^+ e^-$
  Colliders

abstract:
  We discuss perturbative and non-perturbative strong interaction effects in
the pair production of stop squarks ($\tilde{t}_1$) at $e^+ e^-$ colliders.
Events with an additional hard gluon allow to detect or exclude stop pair
production even in scenarios with very small mass splitting between
$\tilde{t}_1$ and an invisible lightest supersymmetric particle (LSP). Such
events can also help to establish that $\tilde{t}_1$ transforms as a triplet
under $SU(3)_C$. We also carefully study non-perturbative $\tilde{t}_1$
fragmentation, which is currently not well understood: not only is the
$\tilde{t}_1$ fragmentation function not known very well, but also there are
ambiguities in the algorithm employed to model fragmentation. We present
numerical results both for CERN LEP-183 and for a proposed future $e^+ e^-$
collider operating at center-of-mass energy $\sqrt{s}=500$ GeV.


title:
Simple Connection Between Atmospheric and Solar Neutrino Vacuum
  Oscillations

abstract:
  Extending the minimal standard model of particle interactions (without
right-handed singlet neutrinos) to include a heavy scalar triplet $\xi$ to
obtain nonzero Majorana neutrino masses, I derive the following simple
realistic connection between atmospheric and solar neutrino vacuum
oscillations: $(\Delta m^2)_{sol} (\Delta m^2)_{atm} / m_\nu^4 ~(\sin^2 2
\theta)_{atm} = 2 I^2$, where $m_\nu$ is the assumed common approximate mass of
each neutrino (which may be suitable for hot dark matter) and $I = (3/16
\pi^2)(G_F/\sqrt 2) m_\tau^2 \ln (m_\xi^2/m_W^2)$ comes from the radiative
splitting of the degeneracy due to the charged leptons.


title:
Simplification of Higher-Twist Evolution in the Large N_c Limit: Why and
  Why Not

abstract:
  Working in the light-cone gauge, we find a simple procedure to calculate the
autonomous one-loop Q^2 evolution of the twist-three part of the nucleon g_T(x,
Q^2) structure function in the large-N_c limit. Our approach allows us to
investigate the possibility of a similar large-N_c simplification for other
higher-twist evolutions. In particular, we show that it does not occur for the
twist-four part of the f_4(x, Q^2), g_3(x, Q^2) and h_3(x, Q^2) distributions.
We also argue that the simplification of the twist-three evolution does not
persist beyond one loop.


title:
The Infrared Limit of the QCD Dirac Spectrum and Applications oc chiral
  Random Matrix Theory to QCD

abstract:
  In the first part of these lectures we discuss the infrared limit of the
spectrum of the QCD Dirac operator. We discuss the global symmetries of the QCD
partition function and show that the Dirac spectrum near zero virtuality is
determined by the pattern of spontaneous chiral symmetry breaking of a QCD-like
partition function with additional bosonic valence quarks and their
super-symmetric partners. We show the existence of an energy scale below which
the fluctuations of the QCD Dirac spectrum are given by a chiral Random Matrix
Theory (chRMT) with the global symmetries of the QCD partition function.
Physically, for valence quark masses below this scale the partition function is
dominated by the zero momentum modes. In the theory of disordered systems, this
energy scale is known as the Thouless energy. In the second part of these
lectures we discuss chRMT as a schematic model for the QCD partition function
at nonzero temperature and chemical potential. We discuss novel features
resulting from the non-Hermiticity of the Dirac operator. The analysis by
Stephanov of the failure of the quenched approximation, the phase diagram of
the chRMT partition function, as well as the properties of Yang-Lee zeros are
discussed. We argue that a localization transition does not occur in the
presence of light quarks. Several results will be derived in full detail. We
mention the flavor symmetries of the QCD Dirac operator for two colors, the
calculation of the valence quark mass dependence of the chiral condensate and
the reduction of the chRMT partition function to the finite volume partition
function.


title:
Determining the Weak Phase $\gamma$ using the decays $B_d$, $B^+ \to K
  \eta (\eta')$ and $B_s \to \pi \eta (\eta')$

abstract:
  We suggest two methods (based on flavor SU(3) symmetry) to determine the CKM
angle $\gamma$ using the decays $B_d$, $B^+ \to K \eta (\eta')$ and $B_s \to
\pi \eta (\eta')$, respectively. Rescattering effects are partly included -- we
neglect annihilation amplitudes, but do not assume any other relation between
the SU(3) invariant amplitudes. We use the fact that the amplitude (including
the Electroweak Penguin contribution) for $B_d$, $B^+ \to \pi K$ with final
state $I (isospin) =3/2$ is known as a function of $\gamma$ from the decay rate
$B^+ \to \pi^0 \pi^+$.


title: Gravitino as a Sterile Neutrino

abstract:
  A scheme is described in which the light gravitino in low energy SUSY
breaking models mixes with neutrinos. The mixing between gravitino and
neutrinos arises through the standard model symmetry breaking and an R-parity
and lepton number violating bilinear term in the superpotential. It is shown
that mixings compatible with the neutrino experiments can be obtained within
the cosmological bound on the bilinear term set by the baryon asymmetry of the
universe.


title: The problem of nonlinear Landau damping in quark-gluon plasma

abstract:
  On the basis of the semiclassical equations for quark-gluon plasma (QGP) and
Yang-Mills equation, the generalized kinetic equation for waves with regard to
its interaction is obtained. The physical mechanisms defining nonlinear
scattering of a plasmon by QGP particles are analysed. The problem on a
connection of nonlinear Landau damping rate of longitudinal oscillation with
damping rate, obtained on the basis of hard thermal loops approximation, is
considered.


title: Electrical Conduction in the Early Universe

abstract:
  The electrical conductivity has been calculated in the early universe at
temperatures below as well as above the electroweak vacuum scale, $T_c\simeq
100$GeV. Debye and dynamical screening of electric and magnetic interactions
leads to a finite conductivity, $\sigma_{el}\sim T/\alpha\ln(1/\alpha)$, at
temperatures well below $T_c$. At temperatures above, $W^\pm$ charge-exchange
processes -- analogous to color exchange through gluons in QCD -- effectively
stop left-handed charged leptons. However, right-handed leptons can carry
current, resulting in $\sigma_{el}/T$ being only a factor $\sim \cos^4\theta_W$
smaller than at temperatures below $T_c$.


title: Measuring sigma(e^+e^- \to hadrons) using tagged photon

abstract:
  We propose to use events with radiated photons in e^+e^- collisions to
measure the total cross section of e^+ e^- \to hadrons as a function of the
center of mass energy. The Monte Carlo simulation for the collider DAPHNE shows
that a competitive accuracy can be achieved with this method.


title: A new proposal for glueball exploration in hard gluon fragmentation

abstract:
  An unambiguous identification of glueballs in experiments will be of great
significance, because their existence is an important test of QCD. The
proposal, advanced here, is to experimentally search for glueballs as peaks in
the invariant mass of a leading K_S-pair fragmenting from an energetic gluon
jet out of high-statistics three-jet events in hadronic decays of the weak
neutral Z boson. Using a physically motivated model of the gluon-glueball
fragmentation function, we find a substantial fragmentation rate into a leading
glueball. It is very likely that a search, along the lines suggested here by
any of the four groups at the Large Electron Positron collider at CERN, will
prove fruitful.


title: Constraints from Charge and Colour Breaking Minima in the (M+1)SSM

abstract:
  We study the constraints on the parameter space of the supersymmetric
standard model extended by a gauge singlet, which arise from the absence of
global minima of the effective potential with slepton or squark vevs.
Particular attention is paid to the so-called ``UFB'' directions in field
space, which are F-flat in the MSSM. Although these directions are no longer
F-flat in the (M+1)SSM, we show that the corresponding MSSM-like constraints on
m_0/M_{1/2} apply also to the (M+1)SSM. The net effect of all constraints on
the parameter space are more dramatic than in the MSSM. We discuss the
phenomenological implications of these constraints.


title: Gluon Squeezed States in QCD Jet

abstract:
  We study evolution of colour gluons and prove the possibility of gluon
squeezed states at the nonperturbative QCD jet stage. Angular and rapidity
dependences of squeezed gluon second correlation function are studied. We
demonstrate that the new gluon states can have both sub-poissonian and
super-poissonian statistics corresponding to antibunching and bunching of
gluons.


title:
Correlation Signs of Instantons in Multigluon Production Processes at
  High Energy

abstract:
  General formula for inclusive gluon distribution on rapidities is obtained
for the processes of multigluon production in classical instanton field with
the first quantum correction. On the basis of this formula second correlation
function is calculated in QCD and analyzed. The features of the correlation
function behaviour can be used as a signal of instanton at HERA.


title:
Unitarity bound for the single-helicity-flip amplitude in elastic
  pp-scattering

abstract:
  On the basis of the U-matrix method of the s-channel unitarization we obtain
a new unitarity bound for the single-helicity-flip amplitude F_5 of elastic
pp-scattering at small values of t


title:
Infra-red stable fixed points of R-parity violating Yukawa couplings in
  supersymmetric models

abstract:
  We investigate the infra-red stable fixed points of the Yukawa couplings in
the minimal version of the supersymmetric standard model with R-parity
violation. Retaining only the R-parity violating couplings of higher
generations, we analytically study the solutions of the renormalization group
equations of these couplings together with the top- and b-quark Yukawa
couplings. We show that only the B-violating coupling $\lambda^{''}_{233}$
approaches a non-trivial infra-red stable fixed point, whereas all other
non-trivial fixed point solutions are either unphysical or unstable in the
infra-red region. However, this fixed point solution predicts a top-quark
Yukawa coupling which is incompatible with the top quark mass for any value of
$\tan\beta$.


title:
Remark on the vectorlike nature of the electromagnetism and the electric
  charge quantization

abstract:
  In this work we study the structure of the electromagnetic interactions and
the electric charge quantization in gauge theories of electroweak interactions
based on semi-simple groups. We show that in the standard model of the
electroweak interactions the structure of the electromagnetic interactions is
strongly correlated to the quantization pattern of the electric charges. We
examine these two questions also in all possible chiral bilepton gauge models
of the electroweak interactions. In all they we can explain the vectorlike
nature of the electromagnetic interactions and the electric charge quantization
together demanding nonvanishing fermion masses and the anomaly cancellations.


title: Gauge Unification in Nonminimal Models with Extra Dimensions

abstract:
  We consider gauge unification in nonminimal models with extra spacetime
dimensions above the TeV scale. We study the possibility that only a a subset
of the supersymmetric standard model gauge and Higgs fields live in the higher
dimensional `bulk'. In two of the models we present, a choice for bulk MSSM
matter fields can be found that preserves approximate gauge unification. This
is true without the addition of any exotic matter multiplets, beyond the chiral
conjugate mirror fields required to make the Kaluza-Klein excitations of the
matter fields vector-like. In a third model, only a small sector of additional
matter fields is introduced. In each of these examples we show that gauge
unification can be obtained without the necessity of large string scale
threshold corrections. We comment briefly on the phenomenology of these models
in the case where the compactification scale is as low as possible.


title: Hard-Photon Emission in e+e- to bar-f f with Realistic Cuts

abstract:
  We derive compact analytical formulae of the Bonneau-Martin type for the
reaction e+e- to bar-f f gamma with cuts on minimal energy and acollinearity of
the fermions, where the photons may be emitted both from the initial or final
states. Soft-photon exponentiation is also taken into account.


title: See-saw and Supersymmetry or Exact R-parity

abstract:
  We show how the renormalizable see-saw mechanism in the context of
supersymmetry and spontaneously broken B-L symmetry implies exact R-parity at
all energies. We argue that supersymmetry plays an important role in providing
a "canonical" form for the see-saw, in particular in grand unified theories
that solve the doublet-triplet splitting problem via the Dimopoulos-Wilczek
mechanism.


title:
Off-diagonal distributions fixed by diagonal partons at small $x$ and
  $\xi$

abstract:
  We show that the off-diagonal (or skewed) parton distributions are completely
determined at small $x$ and $\xi$ by the (conventional) diagonal partons. We
present predictions which can be used to estimate the off-diagonal
distributions at small $x$ and $\xi$ at any scale.


title: Small x Gluons in Nuclei and Hadrons

abstract:
  We numerically study the effects of high gluon density at small x on the
evolution of gluon distribution function in both hadrons and nuclei. Using a
newly derived, Wilson renormalization group-based evolution equation which
includes n to 1 gluon ladder fusion, we find significant reduction in nuclear
gluon distribution function for large nuclei at zero impact parameter at
energies relevant for RHIC and LHC experiments.


title:
Inclusive Hadron Photoproduction from Longitudinally Polarized Protons
  and Deuterons

abstract:
  We report measurements of the asymmetry A_parallel for inclusive hadron
production on longitudinally polarized proton and deuteron targets by
circularly polarized photons. The photons were produced via internal and
external bremsstrahlung from an electron beam of 48.35 GeV. Asymmetries for
both positive and negative signed hadrons, and a subset of identified pions,
were measured in the momentum range 10<P<30 GeV at 2.75 and 5.5 degrees. Small
non-zero asymmetries are observed for the proton, while the deuteron results
are consistent with zero. Recent calculations do not describe the data well.


title: Proposal of Neutrino Flavor Oscillation

abstract:
  A brief survey of the history of the neutrino oscillation is presented. Here
emphasis is laid on the topics around the first proposal of neutrino flavor
oscillation by Nagoya group in 60's. Main contents are presented in my opening
address "Birth of Neutrino Oscillation" at the NOW' 98, Amsterdam,
hep-ph/9811358, but added some detail of the other topics, especially a first
calculation of decay processes $\mu \to e + \gamma$ and $\nu_2 \to \nu_1 +
\gamma$ in terms of neutrino flavor mixing, and some arguments relating to the
massive neutrino.


title: Do Quarks Obey D-Brane Dynamics?

abstract:
  The potential between two D0-branes at rest is calculated to be a linear.
Also the potential between two fast decaying D0-branes is found in agreement
with phenomenological heavy-quark potentials.


title: Higher twist light-cone distribution amplitudes of vector mesons in QCD

abstract:
  We present a systematic study of twist-3 light-cone distribution amplitudes
of vector mesons in QCD, which is based on conformal expansion. A complete set
of distribution amplitudes is constructed for \rho, \omega, K^* and \phi
mesons, which satisfies all (exact) equations of motion and constraints from
conformal expansion.


title: Positive Order H^2 Mass Corrections and Affleck-Dine Baryogenesis

abstract:
  It is usually assumed that the order H^2 corrections to the SUSY-breaking
mass squared terms in the early Universe must be negative in order to allow the
Affleck-Dine mechanism to work. We reconsider this assumption in the context of
D-term inflation models for the case where the mass squared term has a
correction cH^2 with c>0. We show that, in general, the baryon asymmetry is
likely to be too small if c > 9/16. However, for c as large as 0.5 the observed
baryon asymmetry can be readily generated; in particular, for d=6 directions
the observed asymmetry can be produced for a wide range of reheating
temperatures, in contrast with the case of negative H^2 corrections which
require a reheating temperature around 1 GeV. Thus positive H^2 corrections do
not rule out the Affleck-Dine mechanism and can even greatly broaden its
applicability to inflation models.


title: Detection of Neutral MSSM Higgs Bosons at LEP-II and NLC

abstract:
  We study the possibility of detecting the neutral Higgs bosons predicted in
the Minimal Supersymmetric Standard Model (h0, H0, A0), with the reactions e+
e- --> b b h0 (H0, A0), using the helicity formalism. We analyze the region of
parameter space (m_A0-tan beta) where h0(H0, A0) could be detected in the limit
when tan beta is large. The numerical computation is done for the energy which
is expected to be available at LEP-II (sqrt{s} = 200 GeV) and for a possible
Next Linear e+ e- Collider (sqrt{s}=500 GeV).


title:
Single-Spin Asymmetries for Small-Angle Pion Production in High-Energy
  Hadron Collisions

abstract:
  Within the framework of a simple model, we study single-spin asymmetries for
pion production in hadron-hadron collisions at high-energies with one hadron
polarised. The asymmetries are generated via a mechanism of final (initial)
state interactions. For peripheral kinematics, when the pion belongs to the
fragmentation region of the polarised proton, we find non-zero asymmetries in
the high-energy limit. Numerical results and comparision with existing
experimental data are presented. We also discuss the relationship with odderon
exchange phenomenology.


title:
QCD in Extreme Conditions and the Wilsonian `Exact Renormalization
  Group'

abstract:
  This is an introduction to the use of nonperturbative flow equations in
strong interaction physics at nonzero temperature and baryon density. We
investigate the QCD phase diagram as a function of temperature, chemical
potential for baryon number and quark mass within the linear quark meson model
for two flavors. Whereas the renormalization group flow leads to spontaneous
chiral symmetry breaking in vacuum, the symmetry is restored in a second order
phase transition at high temperature and vanishing quark mass. We explicitly
connect the physics at zero temperature and realistic quark mass with the
universal behavior near the critical temperature $T_c$ and the chiral limit. At
high density we find a chiral symmetry restoring first order transition. The
results imply the presence of a tricritical point with long-range correlations
in the phase diagram. We end with an outlook to densities above the chiral
transition, where QCD is expected to behave as a color superconductor at low
temperature.


title: Baryogenesis Below The Electroweak Scale

abstract:
  We propose a new alternative for baryogenesis which resolves a number of the
problems associated with GUT and electroweak scenarios, and which may allow
baryogenesis even in modest extensions of the standard model. If the universe
never reheats above the electroweak scale following inflation, GUT baryon
production does not occur and at the same time thermal sphalerons, gravitinos
and monopoles are not produced in abundance. Nevertheless, non-thermal
production of sphaleron configurations via preheating could generate the
observed baryon asymmetry of the universe.


title:
Non-Spectator Diquark Effects on Lifetimes of \Lambda_b,
  \Omega_{b}^{(*)} and Weak Decay Rates of \Sigma_{b}^{(*)}, \Xi_{b}^{(*)}

abstract:
  The difference of \tau_{_B} and \tau_{_{\Lambda_b}} indicates the role of the
light flavors. We calculate the lifetimes of B-meson and \Lambda_b based on the
weak effective Hamiltonian while assuming the heavy baryon is constructed by a
heavy b-quark and a diquark containing two light quarks. In this scenario, we
use the information of the measured ratio \tau_{_{\Lambda_b}}/\tau_{_B} as
input to predict rates of the inclusive weak decays of \Sigma_{b}^{(*)} and
\Xi_{b}^{(*)} into non-bottom final states. We find that these rates of
\Sigma_{b}^{(*)} and \Xi_{b}^{(*)} are much larger than that of B-mesons and
\Lambda_b. We also give the predictions for the lifetimes of \Omega_b and
\Omega_{b}^{*}. Phenomenological implication of our result is discussed.


title:
Massive $\phi^4$ Model at Finite Temperature -- Resummayion Procedure la
  RG Improvement --

abstract:
  In this paper the phase structure of the massive $\lambda \phi^4$ model at
finite temperature ($T \neq 0$) is investigated by applying a resummation
method inspired by the renormalization-group (RG) improvement to the one-loop
effective potential. The resummation method a la RG-improvement is shown to
work quite succesfully by resumming up systematically large correction-terms of
$O(\lambda T/\mu)$ and of $O(\lambda (T/\mu)^2)$. The temperature-dependent
phase transition of the model is shown to proceed through the second order
transition. The critical exponents are determined analytically and are compared
with those in other analyses.


title: Gauge Symmetry Reduction from the Extra Space $S^1/Z_2$

abstract:
  We study a mechanism of symmetry transition upon compactification of a
5-dimensional field theory on $S^1/Z_2$. The transition occurs unless all
components in a multiplet of a symmetry group have a common $Z_2$ parity on
$S^1/Z_2$. This mechanism is applied to a reduction of SU(5) gauge symmetry in
grand unified theory, and phenomenological implications are discussed.


title: Hunting down the quark-gluon plasma in relativistic heavy-ion collisions

abstract:
  The present status of the heavy-ion program to search for quark-gluon plasma
is reviewed. The goal of this program is to recreate the Big Bang in the
laboratory, by generating small chunks of exploding quark-gluon plasma (``The
Little Bang''). I argue that the analogues of the three pillars of Big Bang
Theory (Hubble flow, microwave background radiation, and primordial
nucleosynthesis) have now been firmly established in heavy-ion collisions at
SPS energies: there is convincing evidence for strong radial flow, thermal
hadron emission, and primordial hadrosynthesis from a color-deconfined initial
stage. Direct observation of the quark-gluon plasma phase via its
electromagnetic radiation will be possible in planned collider experiments at
higher energies.


title: Models of inflation and their predictions

abstract:
  Taking field theory seriously, inflation model-building is difficult but not
impossible. The observed value of the spectral index of the adiabatic density
perturbation is starting to discriminate between models, and may well pick out
a unique one in the forseeable future.


title:
Next-to-Leading Order QCD Corrections to Charged Current Charm
  Production and the Unpolarized and Polarized Strange Sea at HERA

abstract:
  Charged current charm and D meson production is studied in detail as a means
of determining the unpolarized and polarized strange sea densities at HERA. All
analyses are performed in next-to-leading order QCD, including a calculation of
the so far unknown spin-dependent MSbar coefficient functions up to O(alpha_s).
It is shown that a decent measurement is possible in the unpolarized case,
provided a sufficient luminosity can be reached in the future, while for
longitudinally polarized beams it appears to be extremely challenging due to
limitations imposed on the expected statistical accuracy by the charm detection
efficiency.


title:
Quantum mechanics, Furry's hypothesis and a measure of decoherence in
  the K^0 \bar{K}^0 system

abstract:
  We consider strangeness correlations of the EPR type in K^0 \bar{K}^0 pairs
created in a J^{PC} = 1^{--} state as a function of time under the hypothesis
that spontaneous decoherence takes place. We parameterize the degree of
decoherence by a factor (1-\zeta) which multiplies the quantum-mechanical
interference terms occurring in the amplitudes for like and unlike strangeness
events and discuss the dependence of this procedure on the basis chosen in the
K^0--\bar{K}^0 space to which the interference terms correspond. Consequently,
all statements about the ``decoherence parameter'' \zeta inferred from
experimental data are basis-dependent as well. We illustrate this point by
estimating the value of \zeta for the two bases {K_L, K_S} and {K^0, \bar{K}^0}
with the help of recent data of the CPLEAR experiment.


title:
Renormalization Group Effects in the Process $H \longrightarrow \gamma
  \gamma$

abstract:
  The partial Higgs width $\Gamma (H \longrightarrow \gamma \gamma)$ is
important at the LHC for Higgs masses in the MSSM mass window up to 140 GeV as
a relatively background free signal of a fundamental scalar. At the photon
photon mode at the NLC it would be the Higgs production mechanism . Two loop
QCD corrections exist for the fermionic contribution and in the case of the
bottom loop large non-Sudakov double logarithms can be resummed to all orders
and contribute up to 12 % compared to the t-quark. In more complicated Higgs
sectors, such as in the MSSM, large $\tan \beta$ enhancements of bottom type
Yukawa couplings can potentially dominate even the whole partial width. A main
uncertainty in all existing calculations is the scale of the strong coupling as
it is only renormalized at the three loop level. In this paper we include the
exact two loop running coupling to all orders into the bottom contribution. We
find that the effective scale is close to $\alpha_s (10 m_b^2)$.


title:
Unitarized Diffractive Scattering in QCD and Application to Virtual
  Photon Total Cross Sections

abstract:
  The problem of restoring Froissart bound to the BFKL-Pomeron is studied in an
extended leading-log approximation of QCD. We consider parton-parton scattering
amplitude and show that the sum of all Feynman-diagram contributions can be
written in an eikonal form. In this form dynamics is determined by the phase
shift, and subleading-logs of all orders needed to restore the Froissart bound
are automatically provided. The main technical difficulty is to find a way to
extract these subleading contributions without having to compute each Feynman
diagram beyond the leading order. We solve that problem by using nonabelian cut
diagrams introduced elsewhere. They can be considered as colour filters used to
isolate the multi-Reggeon contributions that supply these subleading-log terms.
Illustration of the formalism is given for amplitudes and phase shifts up to
three loops. For diffractive scattering, only phase shifts governed by one and
two Reggeon exchanges are needed. They can be computed from the
leading-log-Reggeon and the BFKL-Pomeron amplitudes. In applications, we argue
that the dependence of the energy-growth exponent on virtuality $Q^2$ for
$\gamma^*P$ total cross section observed at HERA can be interpreted as the
first sign of a slowdown of energy growth towards satisfying the Froissart
bound. An attempt to understand these exponents with the present formalism is
discussed.


title:
Mean Field Dynamics in Non-Abelian Plasmas from Classical Transport
  Theory

abstract:
  Based on classical transport theory, we present a general set of covariant
equations describing the dynamics of mean fields and their statistical
fluctuations in a non-Abelian plasma in or out-of-equilibrium. A procedure to
obtain the collision integrals for the Boltzmann equation from the microscopic
theory is described. As an application, we study a hot non-Abelian plasma close
to equilibrium, where the fluctuations are integrated out explicitly. For soft
fields, and at logarithmic accuracy, we obtain B\"odeker's effective theory.


title: Resonances in radiative hyperon decays

abstract:
  The importance of resonances for the radiative hyperon decays is examined in
the framework of chiral perturbation theory. Low lying baryon resonances are
included into the effective theory and tree contributions to these decays are
calculated. We find significant contributions to both the parity-conserving and
parity-violating decay amplitudes and a large negative value for the asymmetry
parameter in polarized Sigma^+ -> p gamma is found, in agreement with the
experimental result alpha(p Sigma^+) = -0.76 +/- 0.08.


title: Magnetic Fields from Bubble Collisions - A Progress Report

abstract:
  Primordial magnetic fields may be created in collisions of expanding bubbles
in a first-order cosmological phase transition and later serve as seed fields
for galactic magnetic fields. Here I present results from numerical and
analytical studies of U(1) bubble collisions done in collaboration with Ed
Copeland and Paul Saffin. I also reveal preliminary results from analytical
studies of SU(2)xU(1) bubble collisions, which provide first evidence that
magnetic fields are created in electroweak two-bubble collisions.


title: |Delta I|=3/2 Decays of Hyperons in Chiral Perturbation Theory

abstract:
  We study the |Delta I|=3/2 amplitudes of the octet-hyperon decays B -> B' +
pion and of the decays Omega^- -> Cascade + pion in the context of heavy-baryon
chiral perturbation theory. For the octet-hyperon decays, we investigate the
theoretical uncertainty of the lowest-order predictions by calculating the
leading non-analytic corrections. We find that these corrections are within the
expectations of naive power counting and, therefore, that this picture can be
tested more accurately with improved measurements. For the Omega- decays, we
obtain at leading order two operators responsible for the decays which also
contribute at one loop to the octet-hyperon decays. These one-loop
contributions are sufficiently large to suggest that the ratio of measured
widths of Omega^- -> Cascade0 + pion- to Omega^- -> Cascade- + pion0 being
approximately equal to 2.7 may be too large.


title: Probing the MSSM Higgs Sector via Weak Boson Fusion at the LHC

abstract:
  In the MSSM weak boson fusion produces the two CP even Higgs bosons with a
combined strength equivalent to the production of the Standard Model Higgs
boson. The tau tau decay mode --- supplemented by gamma gamma --- provides a
highly significant signal for at least one of the CP even Higgs bosons at the
LHC with reasonable luminosity. The accessible parameter space covers the
entire physical range which will be left unexplored by LEP2.


title:
Day-Night Effect for Solar Neutrinos: Coherent versus Incoherent
  Regeneration in the Earth

abstract: Paper has been withdrawn by the authors.


title:
The Landau-Pomeranchuk-Migdal effect and transition radiation in
  structured targets

abstract:
  The radiation from high-energy electrons is investigated for the case when a
target consists of several separated plates. The spectrum of radiation is
considered in the region in which the bremsstrahlung is under influence of the
multiple scattering of a projectile (the LPM effect), the polarization of a
medium and the hard part of the boundary radiation contribute. In this region
the general expression for the radiation spectrum is obtained for the $N$-plate
target. A qualitative description of the arising interference pattern is given.


title: The Mesonic Chiral Lagrangian of Order $p^6$

abstract:
  We construct the effective chiral Lagrangian for chiral perturbation theory
in the mesonic even-intrinsic-parity sector at order $p^6$. The Lagrangian
contains 112 in principle measurable + 3 contact terms for the general case of
$n$ light flavours, 90+4 for three and 53+4 for two flavours. The equivalence
between equations of motion and field redefinitions to remove spurious terms in
the Lagrangians is shown to all orders in the chiral expansion. We also discuss
and implement other methods for reducing the number of terms to a minimal set.


title: Issues in Quarkonium Production

abstract:
  In this talk, I start with a brief introduction to Non-Relativistic QCD
(NRQCD) and its applications to quarkonium physics. This theory has provided a
consistent framework for the physics of quarkonia, in particular, the
colour-octet Fock components predicted by NRQCD have important implications for
the phenomenology of charmonium production in experiments. The applications of
NRQCD to $J/\psi$ production at Tevatron and the tests of the theory in other
experiments is discussed. In particular, the apparent disagreement of NRQCD
with results from HERA on inelastic photoproduction of $J/\psi$ is discussed
and it is shown that the results are rather susceptible to intrinsic transverse
momentum smearing. The photoproduction data, therefore, do not provide a good
test of NRQCD. It is argued that NRQCD may be tested stringently by looking for
the production of other charmonium resonances at the Tevatron, because the
production rates for these resonances can be predicted within the NRQCD
framework.


title:
Nucleosynthesis Constraints on a Scale-Dependent New Intermediate Range
  Interaction

abstract:
  We derive constraints on the strength of a new intermediate range interaction
that couples to baryon number from primordial nucleosynthesis yields. The
nucleosysnthesis limits here used arise from matching observations and
predictions of standard and inhomogeneous primordial scenarios. We show that
the standard nucleosynthesis scenario is more restrictive ($\alpha_5 \lsim
0.2$) when the range of the interaction is greater than about 1 m. We further
discuss the implications of considering the scalar particle responsible for the
new interaction as the main component of the dark matter in the galactic halo
such that its decay can account for the ionization of hydrogen in the
interstellar medium and the temperature of Lyman-$\alpha$ clouds.


title:
QCD expectations for the spin structure function $g_1$ in the low $x$
  region

abstract:
  The structure function $g_1(x,Q^2)$ is analysed within the formalism based on
unintegrated spin dependent parton distributions incorporating the LO
Altarelli-Parisi evolution and the double $ln^2(1/x)$ resummation at low $x$.
We quantitatively examine possible role of the latter for the small $x$
behaviour of the structure functions $g_1$ of the nucleon within the region
which may be relevant for the possible polarized HERA measurements. We show
that while the non-singlet structure function is dominated at low $x$ by ladder
diagrams the contribution of the non-ladder bremsstrahlung terms is important
for the singlet structure function. Predictions for the polarized gluon
distribution $\Delta G(x,Q^2)$ at low $x$ are also given.


title:
Flux-Tube Ring and Glueball Properties in the Dual Ginzburg-Landau
  Theory

abstract:
  An intuitive approach to the glueball using the flux-tube ring solution in
the dual Ginzburg-Landau theory is presented. The description of the flux-tube
ring as the relativistic closed string with the effective string tension
enables us to write the hamiltonian of the flux-tube ring using the Nambu-Goto
action. Analyzing the Schr\"odinger equation, we discuss the mass spectrum and
the wave function of the glueball. The lowest glueball state is found to have
the mass $M_G \sim 1.6 GeV$ and the size $R_G \sim 0.5 fm$.


title:
The decays "neutrino{heavy} -> neutrino{light} + photon" and
  "neutrino{heavy} -> neutrino{light} e+ e-" of massive neutrinos

abstract:
  If, as recently reported by the Super-Kamiokande collaboration, the neutrinos
are massive, the heaviest one would not be stable and, though chargeless, could
in particular decay into a lighter neutrino and a photon by quantum loop
effects. The corresponding rate is computed in the standard model with massive
Dirac neutrinos as a function of the neutrino masses and mixing angles. The
lifetime of the decaying neutrino is estimated to be approximately 10^44 years
for a mass 5 10^{-2} eV. If kinematically possible, the decay of a heavy
neutrino into a lighter one plus an e+ e- pair occurs at tree level and its
one-loop radiative corrections get enhanced by a large logarithm of the
electron mass acting as an infrared cutoff. It then largely dominates the
photonic mode by several orders of magnitude, corresponding to a lifetime
approximately equal to 10^{-2} year for a mass 1.1 MeV.


title: Soft Yukawa couplings in supersymmetric theories

abstract:
  The possibility of radiatively generated fermion masses arising from chiral
flavor violation in soft supersymmetry-breaking terms is explored. Vacuum
stability constraints are considered in various classes of models, and allow in
principle all of the first- and second-generation quarks and leptons and the
$b$-quark to obtain masses radiatively. Radiatively induced Higgs-fermion
couplings have non-trivial momentum-dependent form factors, which at low
momentum are enhanced with respect to the case of tree-level Yukawa couplings.
These form factors may be probed by various sum rules and relations among Higgs
boson decay widths and branching ratios to fermion final states. An apparent,
large, hard violation of supersymmetry also results for Higgsino couplings.
Mixing between left- and right-handed scalar superpartners is enhanced. A
radiative muon mass is shown to lead to a relatively large and potentially
measurable contribution to the muon anomalous magnetic moment. If the
light-quark masses arise radiatively, the neutron electric dipole moment is
suppressed by a natural phase alignment between the masses and dipole moment,
and is below the current experimental bound. The possibility of neutrino masses
arising from softly broken lepton number, and concomitant enhanced
sneutrino-antisneutrino oscillations, is briefly discussed.


title: Hard Thermal Loops in the Electroweak Theory

abstract:
  We derive a thermal effective action for soft fields in the broken phase of
the electroweak theory in the limit of a strongly interacting Higgs sector.
This action is just the proper generalization of the hard thermal loop
effective action of a Yang-Mills theory when there is a Higgs mechanism and for
a heavy Higgs boson. One can obtain from this action the thermal corrections to
the masses of the W, Z and the photon.


title: Leading soft gluon production in high energy nuclear collisions

abstract:
  The leading soft gluon p_T distribution in heavy ion collisions was obtained
by Kovner, McLerran, and Weigert after solving classical Yang-Mills equations.
I show explicitly this result can be understood in terms of conventional QCD
perturbation theory. I also demonstrate that the key logarithm in their result
represents the logarithm in DGLAP evolution equations.


title: eta and eta' hadronic decays in U_L(3)xU_R(3) Chiral Perturbation Theory

abstract:
  The decays eta/eta' -> pi pi pi and eta' -> eta pi pi are studied up to
leading and next-to-leading order within the framework of U_L(3)xU_R(3) Chiral
Perturbation Theory. The analysis incorporates important features of the
eta-eta' system, such as the contribution of the glueball alphaG\~G due to the
axial anomaly and eta_0/eta_8 mixing. One-loop corrections, which are
third-order contributions according to the combined chiral and 1/Nc expansion,
are not included. Reasonably good results are obtained in most cases.


title:
Electromagnetic Neutrino Properties and Neutrino Oscillations in
  Electromagnetic Fields

abstract:
  The presence of medium and external magnetic field change electromagnetic
properties of neutrino. In this article the behavior of neutrino magnetic
moment in electromagnetic field is considered. On the basis the
Bargmann-Michel-Telegdi equation for the case of models with CP invariance and
P nonconservation the new type of neutrino resonances $\nu_L \leftrightarrow
\nu_R$ in the electromagnetic field is predicted.


title:
Comment on ``Majoron emitting neutrinoless double beta decay in the
  electroweak chiral gauge extensions''

abstract:
  We point out that if the majoron-like scheme is implemented within a 331
model, there must exist at least three different mass scales for the scalar
vacuum expectation values in the model.


title: Non-equilibrium electroweak baryogenesis from preheating after inflation

abstract:
  We present a novel scenario for baryogenesis in a hybrid inflation model at
the electroweak scale, in which the Standard Model Higgs field triggers the end
of inflation. One of the conditions for successful baryogenesis, the departure
from thermal equilibrium, is naturally achieved at the stage of preheating
after inflation. The inflaton oscillations induce large occupation numbers for
long-wavelength configurations of Higgs and gauge fields, which leads to a
large rate of sphaleron transitions. We estimate this rate during the first
stages of reheating and evaluate the amount of baryons produced due to a
particular type of higher dimensional CP violating operator. The universe
thermalizes through fermion interactions, at a temperature below critical,
$T_{rh} < 100$ GeV, preventing the wash-out of the produced baryon asymmetry.
Numerical simulations in (1+1) dimensions support our theoretical analysis.


title: Supersymmetry and Neutrino Masses

abstract:
  Neutrino masses are zero in the minimal supersymmetric standard model. I
discuss how they may become nonzero with new interactions which may or may not
violate R-parity conservation.