title: On the Applicability of Weak-Coupling Results in High Density QCD

abstract:
  Quark matter at asymptotically high baryon chemical potential is in a color
superconducting state characterized by a gap Delta. We demonstrate that
although present weak-coupling calculations of Delta are formally correct for
mu -> Infinity, the contributions which have to this point been neglected are
large enough that present results can only be trusted for mu >> mu_c ~ 10^8
MeV. We make this argument by using the gauge dependence of the present
calculation as a diagnostic tool. It is known that the present calculation
yields a gauge invariant result for mu -> Infinity; we show, however, that the
gauge dependence of this result only begins to decrease for mu > mu_c, and
conclude that the result can certainly not be trusted for mu < mu_c. In an
appendix, we set up the calculation of the influence of the Meissner effect on
the magnitude of the gap. This contribution to Delta is, however, much smaller
than the neglected contributions whose absence we detect via the resulting
gauge dependence.


title: Neutrino oscillations in structured matter

abstract:
  A layered material structure in a monochromatic neutrino beam produces
interference effects that could be used for the measurement of features of the
neutrino mass matrix. The phenomenon would be most useful at high energies.


title:
A comparative study of the D0 neural-network analysis of the top quark
  non-leptonic decay channel

abstract:
  A simpler neural-network approach is presented for the analysis of the top
quark non-leptonic decay channel in events of the D0 Collaboration. Results for
the top quark signal are comparable to those found by the D0 Collaboration by a
more elaborate handling of the event information used as input to the neural
network.


title: Do Neutrinos Decay?

abstract:
  If neutrinos have masses and mixings, in general some will decay. In models
with new particles and new couplings, some decay modes can be fast enough to be
of phenomenological interest.


title: Properties of Regge Trajectories

abstract:
  Early Chew-Frautschi plots show that meson and baryon Regge trajectoies are
approximately linear and non-intersecting. In this paper, we reconstruct all
Regge trajectories from the most recent data. Our plots show that meson
trajectories are non-linear and intersecting. We also show that all current
meson Regge trajectories models are ruled out by data.


title:
Proposal to observe the strong Van der Waals force in the low energy
  neutron-Pb scattering

abstract:
  In the neutron-Pb scattering in the MeV. region, existence of the long range
interaction has been known and people have hopefully expected to understand it
as the effect of the electric polarization of the neutron. However the precise
determination of $\alpha_{n}$ in the very low energy region indicates that the
polarizability of the neutron $\alpha_{n}$ is around two order of magnitude
smaller compared to what is expected in the phenomena in the MeV. region. We
need another strong long range potential which decreases faster than $r^{-4}$.
On the other hand, analysis of the low energy proton-proton data revealed the
existence of the strong long range potential whose tail was $V(r) \sim
-C/r^{\alpha}$ with $\alpha=6.08$. The neuton-nucleus scattering is a good
place to see such a force, since the strength $C$ is magnified by factor $A$,
the mass number. Using the long range parameters obtained in p-p, we predict
the characteristic angular dependency of the n-Pb amplitude for fixed energy.
Appearance of a cusp at $\nu=0$, which points upward, in the once subtracted
P-wave amplitude $a_{1}(\nu)/\nu$ is predicted.


title: Present status of the long range component of the nuclear force

abstract:
  In order to settle the fundamental question whether the nuclear forces
involve the long range components, the S-wave amplitude of the proton-proton
scattering is analysed in search for the extra singularity at $\nu=0$, which
corresponds to the long range force. To facilitate the search, a function,
which is free from the singularities in the neighborhood of $\nu=0$ when all
the interactions are short range, is constructed. The calculation of such a
function from the phase shift data reveals a sharp cusp at $\nu=0$ in
contradiction to the meson theory of the nuclear force. The type of the extra
singularity at $\nu=0$ is close to what is expected in the case of the strong
van der Waals interaction. Physical meanings of the long range force in the
nuclear force are discussed.
  Low energy p-p experiments to confirm directly the strong long range
interaction are also proposed, in which the characteristic interference patten
of the Coulonb and the Van der Waals forces is predicted.


title:
Dynamical Chiral Symmetry Breaking on the Light Front.II. The
  Nambu--Jona-Lasinio Model

abstract:
  An investigation of dynamical chiral symmetry breaking on the light front is
made in the Nambu--Jona-Lasinio model with one flavor and N colors. Analysis of
the model suffers from extraordinary complexity due to the existence of a
"fermionic constraint," i.e., a constraint equation for the bad spinor
component. However, to solve this constraint is of special importance. In
classical theory, we can exactly solve it and then explicitly check the
property of ``light-front chiral transformation.'' In quantum theory, we
introduce a bilocal formulation to solve the fermionic constraint by the 1/N
expansion. Systematic 1/N expansion of the fermion bilocal operator is realized
by the boson expansion method. The leading (bilocal) fermionic constraint
becomes a gap equation for a chiral condensate and thus if we choose a
nontrivial solution of the gap equation, we are in the broken phase. As a
result of the nonzero chiral condensate, we find unusual chiral transformation
of fields and nonvanishing of the light-front chiral charge. A leading order
eigenvalue equation for a single bosonic state is equivalent to a leading order
fermion-antifermion bound-state equation. We analytically solve it for scalar
and pseudoscalar mesons and obtain their light-cone wavefunctions and masses.
All of the results are entirely consistent with those of our previous analysis
on the chiral Yukawa model.


title: Soft pions at high energy and its phenomenological implications

abstract:
  The soft pion theorem in the inclusive reaction at high energy applied to the
current induced reaction is explained briefly. A characteristic aspect of this
theorem is the charge asymmetry produced by the pole terms in the soft pion
limit. The pion charge asymmetry in the central region in the
target-virtual-photon center of the mass (CM) frame of the semi-inclusive
electroproduction and the contribution to the Gottfried sum are illustrated as
examples.


title: Cosmic Tau Neutrinos

abstract:
  The collisions between accelerated protons and the photons present in cosmos
can be a main source of high-energy neutrinos (E \geq 10^6 GeV) of all flavors
above the atmospheric neutrino background. I discuss here the possibility of
photohadronic production of high-energy cosmic tau neutrinos in an
astrophysical site and study some of the effects of vacuum neutrino flavor
mixing on their subsequent propagation. I also discuss the prospects for
observations of these high-energy cosmic tau neutrinos in new large neutrino
telescopes


title: Diffraction at the LHC - antishadow scattering?

abstract:
  Numerical predictions for the global characteristics of proton-proton
interactions are given for the LHC energy. Possibilities for the discovery of
the antishadow scattering mode and its physical implications are discussed.


title: Extracting Matter Effects, Masses and Mixings at a Neutrino Factory

abstract:
  We discuss and quantify different possibilities to determine matter effects,
the value and the sign of $Delta m^2_{31}$, as well as the magnitude of $\sin^2
2\theta_{13}$ in very long baseline neutrino oscillation experiments. We study
neutrino oscillation at a neutrino factory in the $\nu_\mu\to\nu_\mu$
disappearance and $\nu_e\to\nu_\mu$ appearance channels with and without muon
charge identification. One possibility is to analyze the $\nu_e\to\nu_\mu$
appearance channels leading to wrong sign muon events, which requires however
very good muon charge identification. Without charge identification it is still
possible to operate the neutrino factory both with $\mu^-$ and $\mu^+$ beams
and to analyze the differences in the total neutrino event rate spectra. We
show that this leads already to a quite good sensitivity, which may be
important if right sign charge rejection capabilities are insufficient. With
muon charge identification one can study the $\nu_\mu\to\nu_\mu$ disappearance
and the $\nu_e\to\nu_\mu$ appearance channels independently. The best method is
finally achieved by combining all available information of the
$\nu_\mu\to\nu_\mu$ disappearance and $\nu_e\to\nu_\mu$ appearance channels
with charge identification and we show the sensitivity which can be achieved.


title: Cosmology of the Randall-Sundrum model after dilaton stabilization

abstract:
  We provide the first complete analysis of cosmological evolution in the
Randall-Sundrum model with stabilized dilaton. We give the exact expansion law
for matter densities on the two branes with arbitrary equations of state. The
effective four-dimensional theory leads to standard cosmology at low energy.
The limit of validity of the low energy theory and possible deviations from the
ordinary expansion law in the high energy regime are finally discussed.


title: Renormalon Cancellation in Heavy Quarkonia and Determination of m_b, m_t

abstract:
  This is an elementary introduction to the recent significant theoretical
progress in the field of heavy quarkonium physics. We show how renormalon
cancellation takes place in the heavy quarkonium system, such as bottomonium
and (remnant of) toponium resonance, and how this notion is useful in
extracting the MSbar masses of the bottom and top quarks.


title: Power-law inflation with a nonminimally coupled scalar field

abstract:
  We consider the dynamics of power-law inflation with a nonminimally coupled
scalar field $\phi$. It is well known that multiple scalar fields with
exponential potentials $V(\phi)=V_0 {\rm exp}(-\sqrt{16\pi/p m_{\rm pl}^2}
\phi)$ lead to an inflationary solution even if the each scalar field is not
capable to sustain inflation. In this paper, we show that inflation can be
assisted even in the one-field case by the effect of nonminimal coupling. When
$\xi$ is positive, since an effective potential which arises by a conformal
transformation becomes flatter compared with the case of $\xi=0$ for $\phi>0$,
we have an inflationary solution even when the universe evolves as
non-inflationary in the minimally coupled case. For the negative $\xi$, the
assisted inflation can take place when $\phi$ evolves in the region of $\phi<0$
\.


title: Anomalous WW-Gamma Vertex in Gamma-p Collision

abstract:
  The potential of LC+HERAp based Gamma-p collider to probe WW-Gamma vertex is
presented through the discussion of sensitivity to anomalous couplings and P_T
distribution of the final quark. The limits of -0.04<\Delta\kappa<0.04 and
-0.11<\lambda<0.11 at 95% C.L. can be reached with integrated luminosity
200(1/pb). The limit for \Delta\kappa is comparable to one which is expected
from LHC. The bounds are also obtained from corresponding ep collider using
Weizsacker-Williams Approximation to compare with real photons.


title: Lepton Number Violation in Supersymmetric Grand Unified Theories

abstract:
  We argue that the nature of the global conservation laws in Supersymmetric
Grand Unified Theories is determined by the basic vacuum configuration in the
model rather than its Lagrangian. It is shown that the suppression of baryon
number violation in a general (R-parity violating) superpotential can naturally
appear in some extended SU(N) SUSY GUTs which, among other degenerate
symmetry-breaking vacua, have a missing VEV vacuum configuration giving a
solution to the doublet-triplet splitting problem. We construct SU(7) and SU(8)
GUTs where the effective lepton number violating couplings immediately evolve,
while the baryon number non-conserving ones are safely projected out as the GUT
symmetry breaks down to that of the MSSM. However at the next stage, when SUSY
breaks, the radiative corrections shift the missing VEV components to some
nonzero values of order M_{SUSY}, thereby inducing the ordinary Higgs doublet
mass, on the one hand, and tiny baryon number violation, on the other. So, a
missing VEV solution to the gauge hierarchy problem leads at the same time to a
similar hierarchy of baryon vs lepton number violation.


title: Radiative Symmetry Breaking in Brane Models

abstract:
  We propose a way to generate the electroweak symmetry breaking radiatively in
non-supersymmetric type I models with string scale in the TeV region. By
identifying the Higgs field with a tree-level massless open string state, we
find that a negative squared mass term can be generated at one loop. It is
finite, computable and typically a loop factor smaller than the string scale,
that acts as an ultraviolet cutoff in the effective field theory. When the
Higgs open string has both ends confined on our world brane, its mass is
predicted to be around 120 GeV, i.e. that of the lightest Higgs in the minimal
supersymmetric model for large $\tan\beta$ and $m_A$. Moreover, the string
scale turns out to be one to two orders of magnitude higher than the weak
scale. We also discuss possible effects of higher order string threshold
corrections that might increase the string scale and the Higgs mass.


title: Stoponium Search at Photon Linear Collider

abstract:
  In some supersymmetric extensions of the Standard Model fairly light
superpartner of t-quark is predicted, which may form bound states ({\it
stoponiums}) under certain conditions. We study prospects of search for
stoponium at the future Photon Linear Collider. It is found that this machine
could be the best machine for discovery and study of these resonances at some
scenarios of supersymmetric extension of the Standard Model. In particular, if
the $hh$ decay channel is dominant stoponium could be observed at the beginning
of PLC run with collision energy tuned at the stoponium mass. If this channel
is kinematically closed stoponium could be discovered in $gg$, $\gamma\gamma$
and $ZZ$ decay channels but higher statistics are needed. Effects of the
stoponium-Higgs mixing and degeneracy are briefly discussed.


title:
A Covariant Generalization of the Real-Time Green's Functions Method in
  the Theory of Kinetic Equations

abstract:
  A generalized quantum kinetic equation (RKE) of the Kadanoff-Baym type is
obtained on the basis of the Heisenberg equations of motion where the time
evolution and space translation are separated from each other by means of the
covariant method. The same approach is used also for a covariant modification
of the real-time Green's functions method based on the Wigner representation.
The suggested approach does not contain arbitrariness' elements and
uncertainties which often arise from derivation of RKE on the basis of the
motion equations of the Kadanoff-Baym type for the correlation functions in the
case of systems with inner degrees of freedom. Possibilities of the proposed
method are demonstrated by examples of derivation of RKE of the Vlasov type and
collision integrals of the Boltzmann-Uehling-Uhlenbeck (BUU) type in the frame
of the $\sigma \omega$ -version of quantum hadrodynamics, for the simplest case
of spin saturated nuclear matter without antinuclear component. Here, the
quasiparticle approximation in a covariant performance is used. A
generalization of the method for the description of strong non-equilibrium
states based on the non-equilibrium statistical operator is then proposed as
well.


title:
New positivity bounds on polarized parton distributions in multicolored
  QCD

abstract:
  We derive new positivity bounds on spin-dependent parton distributions in
multicolored QCD. They are stronger than Soffer inequality. We check that the
new inequalities are stable under one-loop DGLAP evolution to higher
normalization points.


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

abstract:
  We correct a mistake in the calculation of meson masses at large baryon
chemical potential made in hep-ph/9910491v2


title: Hierarchical Majorana Scales in the Seesaw Model

abstract:
  If the mixing angles in each of the seesaw sectors are all small, and the
neutrino masses are hierarchical, we study the conditions for large neutrino
mixing using triangular matrices. In particular, the implication of the
neutrino oscillation data for the mass hierarchy in the heavy Majorana sector
is examined, and the heavy Majorana scales are shown to depend sensitively on
the solar mixing angle.


title: tau -> omega3pinu Decays

abstract: Theoretical study of anomalous decay mode tau -> omega3pinu is presented.


title:
Effects of Large CP Phases on the Proton Lifetime in Supersymmetric
  Unification

abstract:
  The effects of large CP violating phases arising from the soft SUSY breaking
parameters on the proton lifetime are investigated in supersymmetric grand
unified models. It is found that the CP violating phases can reduce as well as
enhance the proton lifetime depending on the part of the parameter space one is
in. Modifications of the proton lifetime by as much as a factor of 2 due to the
effects of the CP violating phases are seen. The largest effects arise for the
lightest sparticle spectrum in the dressing loop integrals and the effects
decrease with the increasing scale of the sparticle masses. An analysis of the
uncertainties in the determination of the proton life time due to uncertainties
in the quark masses and in the other input data is also given. These results
are of import in the precision predictions of the proton lifetime in
supersymmetric unification both in GUT and in string models when the soft SUSY
breaking parameters are complex.


title: Unity of Fundamental Interactions

abstract:
  The vector representation of the linearized gravitational field (the graviton
field) or the so called quantum gravitodynamics which describes the motion of
masses in a weak gravitational field is employed to understand the unity of the
four known interactions. We propose a gauge group SU(3)xSU(2)xU(1)xU(1) for
such a unified field theory. In this paper we study the SU(2)xU(1)xU(1) sector
of the theory and in analogy to the electroweak mixing angle we define a
gravitoweak mixing angle. The unified gauge field theory predicts the existence
of three massive vector bosons, the Y+/- and the X^0. and two massless vector
bosons, the photon and the graviton (in its vector representation). We
determine the mass spectrum of the Y+/- and the X^0 and predict a modification
to the fine structure constant under unified field conditions. Furthermore, we
briefly discuss the implications of the extended object formulation for the
gauge hierarchy problem.


title:
A three generation oscillation analysis of the Super-Kamiokande
  atmospheric neutrino data beyond one mass scale dominance approximation

abstract:
  In this paper we do a three-generation oscillation analysis of the latest
(848 days) Super-Kamiokande (SK) atmospheric neutrino data going beyond the one
mass scale dominance (OMSD) approximation. We fix $\Delta_{12} = \Delta_{13}$
($\Delta_{LSND}$) in the range 0.5 - 2 eV$^2$ as allowed by the results from
LSND and other accelerator and reactor experiments on neutrino oscillation and
keep $\Delta_{23}$ ($\Delta_{ATM}$) and the three mixing angles as free
parameters. In such a scenario, the oscillation probabilities for the
accelerator and reactor neutrinos involve only two of the mixing angles
  $\theta_{12}$ and $\theta_{13}$ and one mass scale. But the atmospheric
neutrino oscillation is in general governed by both mass scales and all the
three mixing angles. The higher mass scale gives rise to $\Delta m^2$
independent average oscillations for atmospheric neutrinos and does not enter
the $\chi^2$ analysis as an independent parameter. The $\Delta_{23}$ and the
three mixing angles on the other hand appear as independent parameters in the
$\chi^2$ analysis and the best-fit values of these are determined from an
analysis of a) the SK data, b) the SK and CHOOZ data. The allowed values of the
mixing angles $\theta_{12}$ and $\theta_{13}$ from the above analysis are
compared with the constraints from LSND and other accelerator and reactor
experiments. Implications for future long baseline experiments are discussed.


title:
Fermion Electric Dipole Moments in Supersymmetric Models with R-parity
  Violation

abstract:
  We analyze the electron and neutron electric dipole moments induced by
R-parity violating interactions in supersymmetric models. It is pointed out
that dominant contributions can come from one-loop diagrams involving both the
bilinear and trilinear R-parity odd couplings, leading to somewhat severe
constraints on the products of those couplings.


title: Gamma-Ray Bursts

abstract:
  Ultra-high-energy, >10^19 eV, cosmic-ray and high energy, ~10^14 eV, neutrino
production in GRBs is discussed in the light of recent GRB and cosmic-ray
observations. Emphasis is put on model predictions that can be tested with
operating and planned cosmic-ray and neutrino detectors, and on the prospects
of testing for neutrino properties.


title: Bread and Butter Standard Model

abstract:
  Lectures given at the International School of Subnuclear Physics: 37th
Course: Basics and Highlights of Fundamental Physics, Erice, Italy, 29 Aug - 7
Sep 1999.


title:
Different Hagedorn temperatures for mesons and baryons from experimental
  mass spectra, compound hadrons, and combinatorial saturation

abstract:
  We analyze the light-flavor particle mass spectra and show that in the region
up to ~1.8GeV the Hagedorn temperature for baryons is about 30% smaller than
for mesons, reflecting the fact that the number of baryon states grows more
rapidly with the mass. We also show that the spectra are well reproduced in a
model where hadrons are compound objects of quanta, whose available number
increases with mass. The rapid growth of number of hadronic states is a
combinatorial effect. We also point out that an upper limit on the excitation
energy of these quanta results in a maximum number of hadron states that can be
formed. According to this combinatorial saturation, no more light-flavor hadron
resonances exist above a certain mass.


title: Complementary Ansatz for the neutrino mass matrix

abstract:
  We propose a simple Ansatz for the three generation neutrino mass matrix
$M_\nu$ which is motivated from an SO(10) grand unified theory. The Ansatz can
be combined with information from neutrino oscillation experiments and bounds
on neutrinoless double beta decay to determine the neutrino masses themselves
and to reconstruct, with some assumptions, the matrix $ M_\nu $ .


title:
On the Sensitivity of the Polarized Parton Densities to Flavour SU(3)
  Symmetry Breaking

abstract:
  Motivated by the possibility that it may be misleading to assume SU(3)
symmetry in the analysis of hyperon \beta-decays, we study the sensitivity of
the polarized parton densities, derived from the world data on inclusive
polarized deep inelastic lepton-nucleon scattering, to variation of the value
of the nonsinglet axial charge a_8 from its SU(3) value of 3F-D.


title: LR Scalar Mixings and One-loop Neutrino Masses

abstract:
  Within the framework of the complete theory of supersymmetry without
R-parity, where all possible R-parity violating terms are admitted, we perform
a systematic analytical study of all sources of neutrino masses up to ``direct
one-loop" (defined explicitly below) level. In the passing, we present the full
result for squark and slepton masses. In particular, there are interesting $LR$
squark and slepton mixings, which involve both bilinear and trilinear R-parity
violating parameters. The existence and important phenomenological implications
of such terms have been largely overlooked in previous studies. In particular,
in the studies under which either one type of the couplings is assumed to
vanish or neglected, the terms would not show up. The $LR$ mixings play a
central role in neutrino mass generation. Our results look straight forward to
be obtained, which, in our opinion, is an illustration of the effectiveness of
our formulation adopted.


title: Cosmological constraints on R-parity violation from neutrino decay

abstract:
  If the neutrino mass is non-zero, as hinted by several experiments, then
R-parity-violating supersymmetric Yukawa couplings can drive a heavy neutrino
decay into lighter states. The heavy neutrino may either decay radiatively into
a lighter neutrino, or it may decay into three light neutrinos through a
Z-mediated penguin. For a given mass of the decaying neutrino, we calculate its
lifetime for the various modes, each mode requiring certain pairs of
R-parity-violating couplings be non-zero. We then check whether the calculated
lifetimes fall in zones allowed or excluded by cosmological requirements. For
the latter case, we derive stringent new constraints on the corresponding
products of R-parity-violating couplings for given values of the decaying
neutrino mass.


title: Ultrahigh energy neutrino physics

abstract:
  We discuss a problem concerning the ultrahigh energy neutrino propagation
through the Earth. We present calculation of the neutrino-nucleon cross section
at high energies, based on the unifed evolution equation at small x.
  We also show the solution of the transport equation for different neutrino
fluxes originating from active galactic nuclei, gamma ray bursts and top-down
model.


title: R-parity Violating Contribution to Neutron EDM at One-loop Order

abstract:
  We present the full result for the down squark mass-squared matrix in the
complete theory of supersymmetry without R-parity where all kind of R-parity
violating terms are admitted without bias. An optimal parametrization, the
single-VEV parametrization, is used. The major result is a new contribution to
$LR$ squark mixing, involving both bilinear and trilinear R-parity violating
couplings. Among other things, the latter leads to neutron electric dipole
moment at one-loop level. Similiar mechanism leading to electron electric
dipole moment at the same level. We present here a short report on major
features of neutron electric dipole moment from supersymmetry without R-parity
and give the interesting constraints obtained.


title: Parton Skewed Distributions in the Pion and Quark-Hadron Duality

abstract:
  Applying arguments based on the operator product expansion for a three-point
correlator and relying on quark-hadron duality, we derive an expression for the
skewed (non-forward) parton distribution in the pion in the case of a
zero-skewedness parameter, {\cal F}^{\psi|\pi}_{\zeta=0}(X;t). We expect that
our result is relevant for moderately large momentum transfers 1 < t < 10
GeV^2. In addition, we construct a purely phenomenological factorized model for
the same quantity in close analogy to Radyushkin's model, originally proposed
for skewed distributions of quarks in the nucleon. Though the quark-hadron
duality approach supports theoretically the factorized model, the two models
exhibit a different behavior in the parton momentum fraction X at any fixed t.
The relevant process to distinguish between the two options seems to be the
WACS off the pion that measures (to leading t/s-order) the inverse moment
<X^{-1}> of the skewed distribution. Even after the inclusion of the first
order kinematic t/s-corrections, the predictions for the cross section \frac{d
\sigma}{d t}(s,t) at c.m.s. scattering angles \vartheta=30^{\circ} and
90^{\circ} differ by factors 3.5--3.9 and 2.9--7.5, respectively, so that a
discrimination appears possible.


title:
The $\eta_c\gamma \gamma ^*$ transition form factor in the decay
  $\eta_c\to \gamma \ell^+\ell^-$ and in the crossed channels $\gamma e^-\to
  \eta_c e^- $ and $e^+e^-\to\eta_c\gamma

abstract:
  The Dalitz distribution and the effective mass spectrum of the lepton pair
produced in the decay $\eta_c\to \gamma \ell^+ \ell^-$, as well as the
differential cross sections for the crossed channels $\gamma e^-\to \eta_c e^-
$ and $e^+ e^-\to \eta_c \gamma$, are calculated in terms of the sole
electromagnetic transition form factor for the vertex $\eta_c\to\gamma
\gamma^*$, where $\gamma^*$ is a virtual photon with a space-like (for $\gamma
e^- \to \eta_c e^- $) or a time-like (for $e^+ e^-\to \eta_c \gamma$ and
$\eta_c\to\gamma \ell^+\ell^-$) four-momentum. Explicit parametrisations of the
transition form factor are found in two different approaches, namely in Vector
Dominance Model and in a QCD-inspired consideration on the basis of the process
$c \bar{c}\to \gamma \ell^+ \ell^-$, with zero relative three-momentum of the
annihilating quarks.


title: Magnetic Catalysis in the Presence of Scalar Fields

abstract:
  The influence of scalar field interactions in the magnetic catalysis
phenomenom is studied in a gauge theory with scalar and fermion fields. It is
shown that the external magnetic field catalyzes the appearance of a
fermion-antifermion condensate along with a non-zero scalar vev, hence
generating a fermion dynamical mass and breaking the discrete chiral symmetry
of the theory. The model does not require the introduction of a scalar mass
term with a wrong sign in the original Lagrangian to generate the scalar vev,
nor does it exhibit dimensional transmutation ''a la Coleman-Weinberg.'' The
scalar vev noticeably enhances the dynamically generated fermion mass. Possible
cosmological applications of these results are suggested.


title:
Measuring Leptonic CP Violation by Low Energy Neutrino Oscillation
  Experiments

abstract:
  We uncover an interesting phenomenon that neutrino flavor transformation in
slowly varying matter density imitates almost exactly that of vacuum neutrino
oscillation under suitably chosen experimental parameters. It allows us to have
relatively large CP violating measure \Delta P \equiv P(\nu_{\mu} \to \nu_e) -
P(\bar{\nu}_{\mu} \to \bar{\nu}_e) which is essentially free from matter effect
contamination. We utilize this phenomenon to design a low-energy long-baseline
neutrino oscillation experiment to measure the leptonic CP violating phase.


title:
Neutrino Masses and Mixings from Supersymmetry with Bilinear R--Parity
  Violation: A Theory for Solar and Atmospheric Neutrino Oscillations

abstract:
  The simplest unified extension of the MSSM with bi-linear R--Parity violation
naturally predicts a hierarchical neutrino mass spectrum, in which one neutrino
acquires mass by mixing with neutralinos, while the other two get mass
radiatively. We have performed a full one-loop calculation of the
neutralino-neutrino mass matrix in the bi-linear \rp MSSM, taking special care
to achieve a manifestly gauge invariant calculation. Moreover we have performed
the renormalization of the heaviest neutrino, needed in order to get meaningful
results. The atmospheric mass scale and maximal mixing angle arise from
tree-level physics, while solar neutrino scale and oscillations follow from
calculable one-loop corrections. If universal supergravity assumptions are made
on the soft-supersymmetry breaking terms then the atmospheric scale is
calculable as a function of a single \rp violating parameter by the
renormalization group evolution due to the non-zero bottom quark Yukawa
coupling. The solar neutrino problem must be accounted for by the small mixing
angle (SMA) MSW solution. If these assumptions are relaxed then one can
implement large mixing angle solutions, either MSW or just-so. The theory
predicts the lightest supersymmetic particle (LSP) decay to be observable at
high-energy colliders, despite the smallness of neutrino masses indicated by
experiment. This provides an independent way to test this solution of the
atmospheric and solar neutrino anomalies.


title: Non-perturbative gluodynamics of high energy heavy-ion collisions

abstract:
  The dynamics of low-x partons in the transverse plane of a high-energy
nuclear collision is classical, and therefore admits a fully non--perturbative
numerical treatment. We report results of a recent study estimating the initial
energy density in the central region of a collision. Preliminary estimates of
the number of gluons per unit rapidity, and the initial transverse momentum
distribution of gluons, are also provided.


title:
The Weizsacker-Williams Approximation to Trident Production in
  Electron-Photon Collisions

abstract:
  The appears to exist no detailed calculation of the multiphoton trident
process e + n omega_0 -> e' + e+e-, which can occur during the interaction of
an electron beam with an intense laser beam. We present a calculation in the
Weizsacker-Williams approximation that is in good agreement with QED
calculations for the weak-field case.


title: A mass relation for neutrinos

abstract:
  A generalization of the well-known Georgi-Jarlskog relation m_{\mu}/m_{\tau}
= 3 (m_s/m_b) to neutrinos is found in the context of SO(10). This new relation
is m_{\nu_\mu}/m_{\nu_\tau} = 16 (m_c/m_t), which is consistent with present
data, assuming the small-angle MSW solution to the solar neutrino problem.


title:
A new method for extracting the bottom quark Yukawa coupling at the CERN
  Large Hadron Collider

abstract:
  We propose a new method for measuring the H -> bb rate at the CERN LHC in a
manner which would allow extraction of the b quark Yukawa coupling. Higgs boson
production in purely electroweak WHjj events is calculated. The Standard Model
signal rate including decays W -> l nu and H -> bb is 11 fb for M_H = 120 GeV.
It is possible to suppress the principal backgrounds, Wbbjj and ttjj, to
approximately the level of the signal. As the top quark Yukawa coupling does
not appear in this process, it promises a reliable extraction of g_Hbb in the
context of the Standard Model or some extensions, such as the MSSM.


title:
A Novel Possibility to Determine the CP-violating Phase \gamma and the
  B^0_s-\bar{B}^0_s Mixing Parameter y_s at the \Upsilon (5S) Resonance

abstract:
  We show that a CP-violating phase can be model-independently determined from
the time-independent measurement of coherent B^0_s\bar{B}^0_s decays into
(D^{(*)\pm}_s K^{(*)\mp})(D^{(*)\pm}_s K^{(*)\mp}) states at the \Upsilon (5S)
resonance. This phase amounts to (-\gamma) within the standard model, where
\gamma is the well-known angle of the quark mixing unitarity triangle. It is
also possible to determine or constrain the B^0_s-\bar{B}^0_s mixing parameter
y_s from the same measurement.


title: A finite-energy solution in Yang-Mills theory and quantum fluctuations

abstract:
  A finite-energy solution of Yang-Mills theory with a nonstandard lagrangian
is provided. Properties of these solution are studied and also a possible
physical interpretation is given.


title: Confronting Dilaton-exchange gravity with experiments

abstract:
  We study the experimental constraints on theories, where the equivalence
principle is violated by dilaton-exchange contributions to the usual
graviton-exchange gravity. We point out that in this case it is not possible to
have any CPT violation and hence there is no constraint from the CPT violating
measurements in the $K-$system. The most stringent bound is obtained from the
$K_L - K_S$ mass difference. In contrast, neither neutrino oscillation
experiments nor neutrinoless double beta decay imply significant constraints.


title: Effects of quantum space time foam in the neutrino sector

abstract:
  We discuss violations of CPT and quantum mechanics due to interactions of
neutrinos with space-time quantum foam. Neutrinoless double beta decay and
oscillations of neutrinos from astrophysical sources (supernovae, active
galactic nuclei) are analysed. It is found that the propagation distance is the
crucial quantity entering any bounds on EHNS parameters. Thus, while the bounds
from neutrinoless double beta decay are not significant, the data of the
supernova 1987a imply a bound being several orders of magnitude more stringent
than the ones known from the literature. Even more stringent limits may be
obtained from the investigation of neutrino oscillations from active galactic
nuclei sources, which have an impressive potential for the search of quantum
foam interactions in the neutrino sector.


title: The lightest Higgs mass in supersymmetric models with extra dimensions

abstract:
  In the four-dimensional supersymmetric standard model extended with gauge
singlets the lightest Higgs boson mass, $M_H$, has an important contribution
proportional to the squared of the superpotential coupling $\lambda$ of
singlets to Higgs fields, $\lambda SH_1\cdot H_2$. The requirement of
perturbativity up to the unification scale yields an upper bound on $M_H\sim
140$ GeV. In extensions to theories with (longitudinal) extra dimensions at the
TeV where such coupling exists and massive Kaluza-Klein states fall into N=2
representations, if either of the Higgs or singlet fields live in the bulk of
the extra dimensions, the $\beta$-function of $\lambda$ is suppressed due to
the absence of anomalous dimension of hypermultiplets to leading order. This
implies a slower running of $\lambda$ and an enhancement of its low energy
value. The $M_H$ upper bound increases to values $M_H\lesssim 165$ GeV.


title: Topics in Finite Temperature Field Theory

abstract: We discuss a few selected topics in finite temperature field theory.


title: Collision-Induced Decay of Metastable Baby Skyrmions

abstract:
  Many extensions of the standard model predict heavy metastable particles
which may be modeled as solitons (skyrmions of the Higgs field), relating their
particle number to a winding number. Previous work has shown that the
electroweak interactions admit processes in which these solitons decay,
violating standard model baryon number. We motivate the hypothesis that
baryon-number-violating decay is a generic outcome of collisions between these
heavy particles. We do so by exploring a 2+1 dimensional theory which also
possesses metastable skyrmions. We use relaxation techniques to determine the
size, shape and energy of static solitons in their ground state. These solitons
could decay by quantum mechanical tunneling. Classically, they are metastable:
only a finite excitation energy is required to induce their decay. We attempt
to induce soliton decay in a classical simulation by colliding pairs of
solitons. We analyze the collision of solitons with varying inherent
stabilities and varying incident velocities and orientations. Our results
suggest that winding-number violating decay is a generic outcome of collisions.
All that is required is sufficient (not necessarily very large) incident
velocity; no fine-tuning of initial conditions is required.


title: Linear Collider Signal of a Wino LSP in Anomaly Mediated Scenarios

abstract:
  Selectron (smuon) pair-production in a next generation Linear Collider,
yielding a fast electron (muon) trigger, a visible heavily ionizing track
and/or a resolved soft pion impact parameter and overall $\mET$, is shown to
provide a smoking gun signature for Anomaly Mediated Supersymmetry Breaking
models with a neutral Wino as the Lightest Supersymmetric Particle, nearly
mass-degenerate with the lighter chargino.


title: A quasi unitarity bound on the radion mass in the Randall-Sundrum model

abstract:
  In this paper we derive a quasi unitarity bound on the radion mass ($\mphi$)
from the process $hh\to \phi\phi$. We find that at sufficiently high energies
(i.e. when $ s\gg m_h^2, \mphi^2 $) the J=0 partial wave amplitude for the
above process violates unitarity if $\mphi^2 > m_h^2+16 \pi \vphi^2 $.
Combining this result with the unitarity bound $m_h^2<{16\pi v\vphi\over 3}$
obtained from the process $hh\to h\phi$ we get an upper bound of $4\sqrt
{\pi}\vphi [1+{v\over 3 \vphi}]^{1\over 2}$ on the radion mass. This bound is
however valid only in the low energy effective theory where we can ignore the
effects of the gravitational KK modes and the string/M theoretic excitations.


title:
New Directions for New Dimensions: From Strings to Neutrinos to Axions
  to...

abstract:
  In this talk, I discuss recent developments concerning the possibility of
large extra spacetime dimensions. After briefly reviewing how such dimensions
can lower the fundamental GUT, Planck, and string scales, I then outline how
these scenarios lead to a new higher-dimensional seesaw mechanism for
generating neutrino oscillations --- perhaps even without neutrino masses. I
also discuss how extra dimensions lead to new mechanisms contributing to the
``invisibility'' of the QCD axion. This talk reports on work done in
collaboration with Emilian Dudas and Tony Gherghetta.


title: A Brane-World Explanation of the KARMEN Anomaly

abstract:
  Motivated by the anomaly in the KARMEN experiment, we study new possibilities
for brane-world models of neutrino masses. We show that the KARMEN anomaly can
be understood in the context of a six-dimensional brane-world model. The
fine-tuning problem associated with the single-particle interpretation of the
anomaly is thereby alleviated. Our model shows some interesting properties of
general interest for brane-world neutrino physics. In particular, the size of
the brane-bulk mixing decouples from the scales relevant for atmospheric and
solar neutrino oscillations.


title: Propagation of polarized high-energy photons in crystals

abstract:
  The density matrix is obtained for short-wavelength photons passing through a
medium. For sufficiently large thicknesses of a target this matrix is expressed
by the forward scattering amplitude of a photon. For multi-GeV photons
scattering via virtual electron-positron pairs is the most important process.
Its amplitude in a crystal is calculated. The results obtained are used to find
the optimal thicknesses, orientations and types of crystals for the circular -
to - linear polarization conversion process.


title: On Energy Conservation in Lund String Fragmentation

abstract:
  I discuss a Monte Carlo algorithm for hadronization in the Lund string
fragmentation picture, which conserves energy and momentum exactly as is
proposed by the model. An embryo to this Monte Carlo is used to calculate the
total decay density of a string. This is found to reach its predicted
asymptotic behaviour already at a string energy of about six hadron masses.


title:
Models with Inverse Sfermion Mass Hierarchy and Decoupling of the SUSY
  FCNC Effects

abstract:
  We study the decoupling of the first two squark and slepton families in order
to lower the flavour changing neutral current effects. Models with inverse
sfermion mass hierarchy based upon gauged U(1) flavour symmetries provide a
natural framework where decoupling can be implemented. Decoupling requires a
large gap between the Fermi scale and the supersymmetry breaking scale.
Maintaining the electroweak symmetry breaking at the Fermi scale requires some
fine-tuning that we investigate by solving the two-loop renormalization group
equations. We show that the two-loop effects are governed by the anomaly
compensated by the Green-Schwarz mechanism and can be determined from the quark
and lepton masses. The electroweak breaking constraints lead to a small $\mu$
scenario where the LSP is Higgsino-like.


title:
Determination of $\gamma$ from $\bar B^0 \to K^-\pi^+, \pi^-\pi^+$
  Decays

abstract:
  Due a mistake in identifying the operators $O_9$ and $O_{10}$ which leads to
errorous expressions in eq. 9. With the correct expressions (exchange c_9 and
c_{10} in eq. 9), the analysis followed are invalide.


title: The H -> gamma gamma in Multi-Higgs doublet models

abstract:
  We study the dominant decays of the lightest Higgs boson in models with 2 and
3 Higgs doublets, for the case when its couplings to fermions are absent at
tree-level. It is found that the branching ratio for the decay $H\to
\gamma\gamma$ is above the one into fermion pairs, which is evaluated also at
the 1-loop level.


title: Renormalization of the Cabibbo-Kobayashi-Maskawa Matrix

abstract:
  Using the on-shell scheme and the general linear R_xi gauge we have
calculated the one-loop amplitude W+ -> u_I d_j. In agreement with previous
work we have shown that the Cabibbo-Kobayashi-Maskawa (CKM) matrix ought to be
renormalized. We show how to renormalize the CKM matrix and, at the same time,
obtain a gauge independent W decay amplitude.


title:
Neutrino mass matrix suppression by Abelian charges with see-saw
  mechanism

abstract:
  We have investigated a neutrino mass matrix model without supersymmetry
including three see-saw right-handed neutrinos around order $10^{12}$ GeV
masses, aiming at a picture with all small numbers explained as being due to
approximately conserved gauge charges. The prediction of the solar neutrino
mixing angle is given by $\sin^22\theta_{\odot}= 3 {+3\atop -2}\times10^{-2}$;
in fact, the solar mixing angle is, apart from detailed order unity
corrections, equal to the Cabibbo angle. Furthermore the ratio of the solar
neutrino mass square difference to that for the atmospheric neutrino
oscillation is predicted to $6 {+11\atop -4}\times10^{-4}$ and is given by the
same Cabibbo angle related parameter $\xi$ as $6 \xi^4$.


title: Charm in nuclear reactions in sqrt(s)=17 and 19 GeV

abstract:
  Consequences resulting from the D Dbar excess derived indirectly by the NA50
experiment in S+U and Pb+Pb collisions at sqrt(s)=19, 17 GeV, relevant for the
identification of the QCD phase transition in these collisions, are discussed.
The dependence of open and closed charm yields in Pb+Pb collisions on the
number of participating nucleons (N) indicates non thermal charm production and
J/Psi dissociation, stronger than the absorption seen in any other elementary
hadron. The J/Psi in central Pb+Pb collisions could originate dominantly from c
cbar pair coalescence out of a hadronizing quark and gluon environment.
Furthermore, the J/Psi appears to be suppressed in S+U collisions at sqrt(s)=19
GeV, as opposed to current interpretations. A significant change in the
(J/Psi)/D Dbar ratio as well as in the number density of kaons is observed
above energy density approx. 1 GeV/fm^3, suggesting a change of phase at this
energy density, and underlining the importance of direct open charm
measurements.


title: B_{s,d} -> l+ l- in a Two-Higgs-Doublet Model

abstract:
  We compute the branching fractions of B_{s,d} -> l+ l- in the type-II
two-Higgs-doublet model with large tan(beta). We find that the parameters of
the neutral Higgs sector of the two-Higgs-doublet model cancel in the result,
so that the branching fractions depend only on the charged Higgs mass and
tan(beta). For large values of tan(beta) and a charged Higgs mass above the
bound from b -> s gamma, we find that the branching fractions can be enhanced
by up to an order of magnitude or suppressed by up to a factor of two compared
to the Standard Model result. We point out that previous calculations in the
literature are gauge-dependent due to the omission of an important diagram,
which gives the dominant contribution in the 't Hooft-Feynman gauge. We have
analyzed in detail the region of the (M_{H^+}, tan(beta)) plane to be probed by
searches for B_s -> mu+ mu- in Run II of the Tevatron. Since the branching
fraction increases like tan^4(beta), this decay mode is complementary to b -> s
gamma and efficiently probes the large tan(beta) region. For tan(beta)=60, an
integrated luminosity of 20 fb^{-1} in an extended Run II will probe charged
Higgs masses up to 260 GeV, if the background to B_s -> mu+ mu- is small. For
the same value of tan(beta), the LHC may be able to explore charged Higgs
masses up to 1 TeV using this decay.


title: Pade-Improved Estimates of Hadronic Higgs Decay Rates

abstract:
  Asymptotic Pade-approximant methods are utilized to estimate the order
$\alpha_s^5$ contribution to the $H\to gg$ rate and the order $\alpha_s^4$
contribution to the $H \to b \bar{b}$ rate. The former process is of particular
interest because of the slow convergence evident from the three known terms of
its QCD series, which begins with an order $\alpha_s^2$ leading-order term. The
order $\alpha_s^5$ contribution to the $H \to gg$ rate is expressed as a
degree-3 polynomial in $L \equiv ln (\mu^2 / m_t^2 (\mu))$. We find that
asymptotic Pade-approximant predictions for the coefficients of $L$, $L^2$, and
$L^3$ are respectively within 1%, 2%, and 7% of true values extracted via
renormalization-group methods. Upon including the full set of next-order
coefficients, the $H \to gg$ rate is found to be virtually scale-independent
over the 0.3 $M_{H} < \mu < M_t$ range of the renormalization scale-parameter
$\mu$. We conclude by discussing the small order $\alpha_s^4$ contribution to
the $H \to b \bar{b}$ rate, which is obtained from a prior asymptotic
Pade-approximant estimate of the order $\alpha_s^4$ contribution to the
quark-antiquark scalar-current correlation function.


title: The Infrared Behavior of QCD Propagators in Landau Gauge

abstract:
  Some features of the solutions to the truncated Dyson-Schwinger
equations(DSEs) for the propagators of QCD in Landau gauge are summarized. In
particular, the Kugo-Ojima confinement criterion is realized, and positivity of
transverse gluons is manifestly violated in these solutions. In Landau gauge,
the gluon-ghost vertex function offers a convenient possibility to define a
nonperturbative running coupling. The infrared fixed point obtained from this
coupling which determines the 2-point interactions of color-octet quark
currents implies the existence of unphysical massless states which are
necessary to escape the cluster decomposition of colored clusters. The gluon
and ghost propagators, and the nonperturbative running coupling, are compared
to recent lattice simulations. A significant deviation of the running coupling
from the infrared behavior extracted in simulations of 3-point functions is
attributed to an inconsistency of asymmetric subtraction schemes due to a
consequence of the Kugo-Ojima criterion: infrared enhanced ghosts.


title: Electromagnetic form factors of nucleons and Delta*

abstract:
  A relativistic quark model and a new set of wave functions of nucleon and
Delta have been used to study the electromagnetic propertities of (1/2)^+
baryons and photoelectric production of Delta(1236).


title: Recalculation of Proton Compton Scattering in Perturbative QCD

abstract:
  At very high energy and wide angles, Compton scattering on the proton (gamma
p -> gamma p) is described by perturbative QCD. The perturbative QCD
calculation has been performed several times previously, at leading twist and
at leading order in alpha_s, with mutually inconsistent results, even when the
same light-cone distribution amplitudes have been employed. We have
recalculated the helicity amplitudes for this process, using contour
deformations to evaluate the singular integrals over the light-cone momentum
fractions. We do not obtain complete agreement with any previous result. Our
results are closest to those of the most recent previous computation, differing
significantly for just one of the three independent helicity amplitudes, and
only for backward scattering angles. We present results for the unpolarized
cross section, and for three different polarization asymmetries. We compare the
perturbative QCD predictions for these observables with those of the handbag
and diquark models. In order to reduce uncertainties associated with alpha_s
and the three-quark wave function normalization, we have normalized the Compton
cross section using the proton elastic form factor. The theoretical predictions
for this ratio are about an order of magnitude below existing experimental
data.


title:
pp Elastic Scattering at LHC and Signature of Chiral Phase Transition at
  Large |t|

abstract:
  A model of $pp$ and $\bar{p}p$ elastic scattering developed previously to
analyze ISR and SPS Collider data is extended to predict $pp$ elastic
differential cross section at LHC at c.m. energy of 14 TeV and momentum
transfer range $|t|=0$ - 10 GeV$^2$. Role of the gauged linear $\sigma$-model
as an underlying field theory model describing nucleon structure and elastic
scattering is discussed. Possibility of finding evidence of a chiral phase
transition at large $|t|$ in the proposed TOTEM project at LHC is pointed out.


title: Quantum mechanics of baryogenesis

abstract:
  The cosmological baryon asymmetry can be explained as remnant of heavy
Majorana neutrino decays in the early universe. We study this
out-of-equilibrium process by means of Kadanoff-Baym equations which are solved
in a perturbative expansion. To leading order the problem is reduced to solving
a set of Boltzmann equations for distribution functions.


title: Leontovich Relations in Thermal Field Theory

abstract:
  The application of generalized Kramers-Kronig relations, the so-called
Leontovich relations, to thermal field theory is discussed. Medium effects
contained in the full, thermal propagators can easily be taken into account by
this method. As examples the collisional energy loss of a charged particle in a
relativistic plasma and the radiation of energetic photons from a quark-gluon
plasma are considered. Within the leading logarithmic approximation the results
based on the hard thermal loop resummation technique are reproduced easily.
However, the method presented here is more general and provides exact
expressions, which allow in principle non-perturbative calculations.


title: Spectra of Doubly Heavy Quark Baryons

abstract:
  Baryons containing two heavy quarks are treated in the Born-Oppenheimer
approximation. Schr\"odinger equation for two center Coulomb plus harmonic
oscillator potential is solved by the method of ethalon equation at large
intercenter separations. Asymptotical expansions for energy term and wave
function are obtained in the analytical form. Using those formulas, the energy
spectra of doubly heavy baryons with various quark compositions are calculated
analytically.


title:
Relaxation of the Dynamical Gluino Phase and Unambiguous Electric Dipole
  Moments

abstract:
  We propose a new axionic solution of the strong CP problem with a
Peccei-Quinn mechanism using the gluino rather than quarks. The spontaneous
breaking of this new global U(1) at 10^{11} GeV also generates the
supersymmetry breaking scale of 1 TeV (solving the so-called \mu problem at the
same time) and results in the MSSM (Minimal Supersymmetric Standard Model) with
R parity conservation. In this framework, electric dipole moments become
calculable without ambiguity.


title:
Charge asymmetry due to the soft pion at high energy and its effect on
  the sea quark

abstract:
  Using the soft pion theorem in the inclusive reactions, we estimate the soft
pion contribution to the structure functions $F_2$ and $g_1$ in the nucleon,
and show that it is an indispensable part in these structure functions in the
small $x$ region. This contribution is asymmetric for the soft $\pi^+$ and
$\pi^-$ due to pole terms in the soft pion limit, hence it is a remnant of the
spontaneous chiral symmetry breakings. Then we show that the modified strange
sea quark where the soft pion contribution is added to the distribution
determined by the ansatz (strange-sea)=(up-sea + down-sea)/4 satisfies the mean
charge sum rule for the sea quarks.


title: Elastic pp and $\bar pp$ scattering in the Modified Additive Quark Model

abstract:
  The modified additive quark model, proposed recently, allows to improve
agreement of the standard additive quark model with the data on the $pp, \bar
pp, \pi^{\pm} p, \gamma p$ and $\gamma \gamma$ total cross-sections, as well as
on the ratios of real to imaginary part of $pp$ and $\bar pp$ amplitudes at
$t=0$. Here, we extend this model to non forward elastic scattering of protons
and antiprotons. A high quality reproduction of angular distributions at 19.4
GeV $\leq \sqrt{s}\leq $ 1800 Gev is obtained. A zero at small $|t|$ in the
real part of even amplitude in accordance with a recently proved high energy
general theorem is found.


title:
The Super - Kamiokande Day - Night Effect Data and the MSW Solutions of
  the Solar Neutrino Problem

abstract:
  The current Super-Kamiokande data on the D-N asymmetry between the the day
event rate and the {\it Night} and {\it Core} event rates, produced by solar
neutrinos which respectively cross the Earth along any trajectory and cross the
Earth core before reaching the detector, imply rather stringent constraints on
the MSW small mixing angle (SMA) $\nu_e \to \nu_{\mu(\tau)}$ solution of the
solar neutrino problem. A simplified analysis shows, in particular, that a
substantial subregion of the SMA solution region is disfavored by these data.
The {\it Core} D-N asymmetry data alone allow to rule out at 99.7% C.L. a part
of this subregion. The constraints on the MSW large mixing angle and LOW $\nu_e
\to \nu_{\mu(\tau)}$ solutions as well as on the MSW $\nu_e \to \nu_{s}$
solution, following from the data on the {\it Night} and {\it Core} D-N
asymmetries are also discussed.


title: BCP3: Summary of Theory

abstract:
  I discuss a number of the highlights in theory presented at the BCP3
conference. These included new, and more stringent, CKM fits; a critical
overview of heavy hadron lifetimes; progress in computing rates and
CP-asymmetries in charmless B-decays; a thorough discussion of the implications
of the new results on $\epsilon^{\prime}/\epsilon$; and, finally, a peek at the
future, trying to estimate how well one is going to be able to measure the
unitarity triangle angles.


title:
On Unitarity Based Relations Between Various Lepton Family Violating
  Processes

abstract:
  Simple "unitarity inspired" relations between two- and three-body lepton
flavor violating decays are noted and discussed. In the absence of
cancellations, the existing strong bounds on $\mu \to 3e$ and $ \mu\to
e\gamma\gamma$ severly constrain two-body lepton flavor violating decays.


title: Phenomenology of Neutrino Oscillations

abstract:
  The phenomenology of solar, atmospheric, supernova and laboratory neutrino
oscillations is described. Analytical formulae for matter effects are reviewed.
The results from oscillations are confronted with neutrinoless double beta
decay.


title: No CPT Violation from Tilted Brane in Neutral Meson--Antimeson Systems

abstract:
  Tilted brane in theories with large compact extra dimensions leads to
spontaneous symmetry breaking of the Lorentz and rotational invariance in four
dimensions, as shown by Dvali and Shifman. In this brief report, we point out
that the mentioned Lorentz symmetry breaking, although leading to the
CPT--violating interaction terms, cannot lead to the CPT violation in the
experimentally interesting $K$--${\bar K}$ and analogous systems.


title: Electromagnetic and gravitational decay of the Higgs boson

abstract:
  The decays of a scalar particle, of either parity, into two photons or into
two gravitons are evaluated. The effective interactions are of the form $\phi
FF, \phi F\tilde{F}$ or $\phi RR,\phi R\tilde{R}$; in particular, Higgs boson
decay into gravitons cannot be adduced to an interaction $\phi R$, as has been
recently claimed.


title: Light Quark Masses to All Orders of Chiral Expansion

abstract:
  We study light (current) quark masses in framework of chiral constitutent
quark model. In our calculation the current quark masses are defined uniquely,
and all order effects of the light quark masses are considered. The results at
energy scale $\mu=m_\rho$ are $m_s=(160\pm 15)$MeV, $m_s/m_d=20.2\pm 3.0$,
$m_u/m_d=0.5\pm 0.09$.


title:
Weak and Magnetic Inelastic Scattering of Antineutrinos on Atomic
  Electrons

abstract:
  Neutrino scattering on electrons is considered as a tool for laboratory
searches of the neutrino magnetic moment. We study inelastic
$\bar\nu_ee^-$-scattering on electrons bound in the germanium (Z=32) and iodine
(Z=53) atoms for antineutrinos generated in a nuclear reactor core and also in
the $^{90}$Sr-$^{90}$Y and $^{147}$Pm artificial sources. Using the
relativistic Hartree-Fock-Dirac model, we calculate both the magnetic and weak
scattering cross sections for the recoil electron energy range of 1 to 100 keV
where a higher sensitivity to the neutrino magnetic moment could be achieved.
Particular attention is paid to the approximate procedure which allows us to
take into account the effects of atomic binding on the inelastic scattering
spectra in a simple way.


title: Relaxing Near the Critical Point

abstract:
  Critical slowing down of the relaxation of the order parameter is relevant
both in early the universe and in ultrarelativistic heavy ion collisions. We
study the relaxation rate of the order parameter in an O(N) scalar theory near
the critical point to model the non-equilibrium dynamics of critical
fluctuations near the chiral phase transition.A lowest order perturbative
calculation (two loops in the coupling lambda) reveals the breakdown of
perturbation theory for long-wavelength fluctuations in the critical region and
the emergence of a hierarchy of scales with hard q>T, semisoft T >> q >> lambda
T and soft lambda T>>q loop momenta which are widely separated for weak
coupling. The non-perturbative resummation in the large N limit reveals the
renormalization of the interaction and the crossover to an effective 3D-theory
for soft momenta.The effective 3D coupling goes to the Wilson-Fisher 3D fixed
point in the soft limit.The relaxation rate of the order parameter for wave
vectors lambda T >>k>> k_{us} or near the critical temperature lambda
T>>m_T>>k_{us} with the ultra soft scale k_{us} = [(lambda T)/(4pi)]
exp[-(4pi/lambda)] is dominated by classical semisoft loop momentum leading to
Gamma(k,T) = lambda T/(2 pi N). For wavectors k<< k_{us} the damping rate is
dominated by hard loop momenta and given by Gamma(k,T)=4 pi T/[3N ln(T/k)].
Analogously, for homogeneous fluctuations in the ultracritical region
m_T<<k_{us} the damping rate is given by Gamma_0(m_T,T)=4 pi T/[3N ln(T/m_T)].
Thus critical slowing down emerges for ultrasoft fluctuations where the rate is
lambda-independent. The strong coupling regime and the shortcomings of the
quasiparticle interpretation are discussed.


title: Tau neutrinos from muon storage rings

abstract:
  Charged tau leptons emerging in a long baseline experiment with a muon
storage ring and a far-away detector will positively establish neutrino
oscillations. We study the conversion of $\nu_\mu$ ($\bar{\nu}_\mu$) and of
$\bar{\nu}_e$ ($\nu_e$) to $\nu_\tau$ or $\bar{\nu}_\tau$ for neutrinos from a
20 GeV muon storage ring, within the strong mixing scheme and on the basis of
the squared mass differences which are compatible with all reported neutrino
anomalies, including the LSND data. In contrast to other solutions which ignore
the Los Alamos anomaly, we find charged tau production rates which should be
measurable in a realistic set up. As a consequence, determining the complete
mass spectrum of neutrinos as well as all three mixing angles seems within
reach. Matter effects are discussed thoroughly but are found to be small in
this situation.


title: Search for new physics with ATLAS at the LHC

abstract:
  Due to the high energy and luminosity of the LHC, the ATLAS experiment has a
huge discovery potential for new physics. A Standard Model Higgs boson can be
discovered over the full range of allowed masses, and its mass should be
measured with a precision of about 0.1%. The Higgs sector of the MSSM should be
fully explored by searches for supersymmetric Higgs bosons. Squarks and gluinos
can be discovered up to masses of 2.5 TeV and several precision measurements
can be performed in the SUSY sector. The existence of particles predicted by
other theories beyond the Standard Model has been also investigated.


title: Neutrino propagation in matter using the wave packet approach

abstract:
  We study the oscillations and conversions of relativistic neutrinos
propagating in matter of variable density using the wave packet formalism. We
show how the oscillation and coherence lengths are modified in comparison with
the case of oscillations in vacuum. Secondly, we demonstrate how the equation
of motion for two neutrino flavors can be formally solved for almost arbitrary
density profile. We calculate finally how the use of wave packets alters the
nonadiabatic level crossing probabilities. For the most common physical
environments the corrections due to the width of the wave packet do not lead to
observable effects.


title: Second Cluster Integral and Excluded Volume Effects for the Pion Gas

abstract:
  The quantum mechanical formula for Mayer's second cluster integral for the
gas of relativistic particles with hard-core interaction is derived. The proper
pion volume calculated with quantum mechanical formula is found to be an order
of magnitude larger than its classical evaluation.
  The second cluster integral for the pion gas is calculated in quantum
mechanical approach with account for both attractive and hard-core repulsive
interactions. It is shown that, in the second cluster approximation, the
repulsive pion-pion-interactions as well as the finite width of resonances give
important but almost canceling contributions. In contrast, an appreciable
deviation from the ideal gas of pions and pion resonances is observed beyond
the second cluster approximation in the framework of the Van der Waals
excluded-volume model.


title: $K_L\to\gamma\nu\bar{\nu}$ in the Light Front Model

abstract:
  We study the CP conserving and violating contributions to the decay of
$\knng$ in the standard model. In our analysis, we use the form factors for
$K\to\gamma$ transitions calculated directly in the entire physical range of
momentum transfer within the light front model. We find that the branching
ratios for the CP conserving and violating parts are about $1.0\times 10^{-13}$
and $1.5\times 10^{-15}$, respectively.


title:
QED in a Strong External Magnetic Field: Beyond the Constant Mass
  Approximation

abstract:
  We solve the Schwinger-Dyson equations for QED in 2+1 or 3+1 dimensions in
the presence of a strong homogeneous external magnetic field. The magnetic
field is assumed strong enough, so that the lowest Landau level approximation
holds, but the usual assumption of a momentum-independent self-energy is not
made. In 2+1 dimensions, the scaling with logarithm changes to a square root
dependence on the magnetic field, but the most spectacular result takes place
in 3+1 dimensions, where the constant mass approximation turns out to be
unreliable and the (momentum-dependent) dynamical mass is larger by several
orders of magnitude compared to what has been found till now using the constant
mass approximation.


title: Neutrinos and Gauge Unification

abstract:
  The approximate unification of gauge couplings is the best indirect evidence
for low-energy supersymmetry, although it is not perfect in its simplest
realizations. Given the experimental evidence for small non-zero neutrino
masses, it is plausible to extend the MSSM with three right-handed neutrino
chiral multiplets, with large Majorana masses below the unification scale, so
that a see-saw mechanism can be implemented. In this extended MSSM, the
unification prediction for the strong gauge coupling constant at M_Z can be
lowered by up to \sim 5%, bringing it closer to the experimental value at
1\sigma, therefore improving significantly the accuracy of gauge coupling
unification.


title: Higgs boson decay to mu mubar gamma

abstract:
  The Higgs boson decay, H -> mu mubar gamma, is studied in the Standard Model
at the tree and one-loop levels. It is shown that for Higgs boson masses above
110 GeV, the contribution to the radiative width from the one-loop level
exceeds the contribution from the tree level, and for Higgs boson masses above
140 GeV, it even exceeds the contribution from the tree level decay H -> mu
mubar. We also show that the contributions to the radiative decay width from
the interference terms between the tree and one-loop diagrams are negligible.


title: Mixing and CP violation with Quasidegenerate Majorana Neutrinos

abstract:
  We study the exactly degenerate case for three lefthanded Majorana neutrinos
building a general parametrization for the leptonic mixing matrix characterized
by two angles and one CP violating phase and identify a weak-basis invariant
relevant, in this case, for CP violation. After lifting the degeneracy, this
parametrization accommodates the present data on atmospheric and solar
neutrinos, as well as neutrinoless double beta decay. Some of the leptonic
mixing ans\"atze suggested in the literature correspond to special cases of
this parametrization.


title: Supersymmetric Dark Matter in the Light of LEP and the Tevatron Collider

abstract:
  We analyze the accelerator constraints on the parameter space of the Minimal
Supersymmetric extension of the Standard Model, comparing those now available
from LEP II and anticipating the likely sensitivity of Tevatron Run II. The
most important limits are those from searches for charginos, neutralinos and
Higgs bosons at LEP, and searches for stop squarks, charginos and neutralinos
at the Tevatron Collider. We also incorporate the constraints derived from b
--> s + gamma decay, and discuss the relevance of charge- and colour-breaking
minima in the effective potential. We combine and compare the different
constraints on the Higgs-mixing parameter mu, the gaugino-mass parameter
m_{1/2} and the scalar-mass parameter m0, incorporating radiative corrections
to the physical particle masses. We focus on the resulting limitations on
supersymmetric dark matter, assumed to be the lightest neutralino,
incorporating coannihilation effects in the calculation of the relic abundance.
We find that m_chi > 51 GeV and tan(beta) > 2.2 if all soft
supersymmetry-breaking scalar masses are universal, including those of the
Higgs bosons, and that these limits weaken to m_chi > 46 GeV and tan(beta) >
1.9 if non-universal scalar masses are allowed. Light neutralino dark matter
cannot be primarily Higgsino in composition.


title:
The Neutron Electric Dipole Moment and CP-violating Couplings in the
  Supersymmetric Standard Model without R-parity

abstract:
  We analyze the neutron electric dipole moment (EDM) in the Minimal
Supersymmetric Model with explicit R-parity violating terms. The leading
contribution to the EDM occurs at the 2-loop level and is dominated by the
chromoelectric dipole moments of quarks, assuming there is no tree-level
mixings between sleptons and Higgs bosons or between leptons and gauginos.
Based on the experimental constraint on the neutron EDM, we set limits on the
imaginary parts of complex couplings ${\lambda'}_{ijk}$ and ${\lambda}_{ijk}$
due to the virtual b-loop or tau-loop.


title: A Two Parameter Texture of Nearly Bi-maximal Neutrino Mixing

abstract:
  We propose a texture of three generation Majorana-type neutrino mass matrix
in terms of only two parameters which gives rise to nearly bi-maximal mixing
angles. We also demonstrate an explicit realization of such type of neutrino
mass-matrix in the context of an $SU(2)_L$$\times$$U(1)_Y$ model due to higher
dimensional mass terms through the inclusion of discrete $Z_3$$\times$$Z_4$
symmetry and two extra singlet Higgs fields.


title: On the Drell-Levy-Yan Relation to $O(\alpha_s^2)$

abstract:
  We study the validity of a relation by Drell, Levy and Yan (DLY) connecting
the deep inelastic structure (DIS) functions and the single-particle
fragmentation functions in e^+e^- annihilation which are defined in the
spacelike (q^2<0) and timelike (q^2>0) regions respectively. Here q denotes the
momentum of the virtual photon exchanged in the deep inelastic scattering
process or the annihilation process. An extension of the DLY-relation, which
originally was only derived in the scaling parton model, to all orders in QCD
leads to a connection between the two evolution kernels determining the
q^2-dependence of the DIS structure functions and the fragmentation functions
respectively. In relation to this we derive the transformation relations
between the space-and time-like splitting functions up to next-to-leading order
(NLO) and the coefficient functions up to NNLO both for unpolarized and
polarized scattering. It is shown that the evolution kernels describing the
combined singlet evolution for the structure functions F_2(x,Q^2), F_L(x,Q^2)
where Q^2=|q^2| or $F_2(x,Q^2), \partial F_2(x,Q^2)/\partial \ln(Q^2)$ and the
corresponding fragmentation functions satisfy the DLY relation up to
next-to-leading order. We also comment on a relation proposed by Gribov and
Lipatov.


title: Penguin Enhancement and $B\to K\pi$ decays in perturbative QCD

abstract:
  We compute branching ratios of $B\to K\pi$ decays in the framework of
perturbative QCD factorization theorem. Decay amplitudes are classified into
the topologies of tree, penguin and annihilation, all of which contain both
factorizable and nonfactorizable contributions. These contributions are
expressed as the convolutions of hard $b$ quark decay amplitudes with universal
meson wave functions. It is shown that (1) matrix elements of penguin operators
are dynamically enhanced compared to those employed in the factorization
assumption; (2) annihilation diagrams are not negligible, contrary to common
belief; (3) annihilation diagrams contribute large strong phases; (4) the
uncertainty of current data of the ratio $R={\cal B}(B_d^0\to
K^\pm\pi^\mp)/{\cal B}(B^\pm\to K^0\pi^\pm)$ and of CP asymmetries is too large
to give a constraint of $\phi_3$. Assuming $\phi_3=90^o$ which is extracted
from the best fit to the data of $R$, predictions for the branching ratios of
the four $B\to K\pi$ modes are consistent with data.


title: Forward jets in the colour-dipole model

abstract:
  We show that a forward jet with large transverse momentum in an onium-onium
collision is a hard probe which can be effectively characterized by a colour-
dipole distribution at the time of the interaction. The dipole distribution is
computed, and compared to its counterpart for a virtual photon in the initial
state. We find that while in the photon case, the tail of large sizes is
exponentially cut-off, it contributes sizeably in the forward-jet case, which
signs the sensitivity of observables based on such events to the infrared
region. Moreover, a direct probabilistic interpretation of the dipole
distribution fails since it takes negative values in the large size region.


title: New RG-invariants of Soft Supersymmetry Breaking Parameters

abstract:
  We study new renormalization-group invariant quantities of soft supersymmetry
breaking parameters other than the ratio of gaugino mass to gauge coupling
squared by using the spurion method. The obtained invariants are useful to
probe supersymmetry breaking and mu-term generation mechanisms at high-energy
scale. We also discuss the convergence behavior of fixed points of
supersymmetry breaking parameters.


title: Nuclear geometry of jet quenching

abstract:
  The most suitable way to study the jet quenching as a function of distance
traversed is varying the impact parameter b of ultrarelativistic
nucleus-nucleus collision (initial energy density in nuclear overlapping zone
is almost independent of b up to b R_A). It is shown that b-dependences of
medium-induced radiative and collisional energy losses of a hard parton jet
propagating through dense QCD-matter are very different. The experimental
verification of this phenomenon could be performed for a jet with non-zero cone
size basing on essential difference between angular distributions of
collisional and radiative energy losses.


title:
Weyl Invariant Formulation of Flux-Tube Solution in the Dual
  Ginzburg-Landau Theory

abstract:
  The flux-tube solution in the dual Ginzburg-Landau (DGL) theory in the
Bogomol'nyi limit is studied by using the manifestly Weyl invariant form of the
DGL Lagrangian. The dual gauge symmetry is extended to $[U(1)]_m^3$, and
accordingly, there appear three different types of the flux-tube. The string
tension for each flux-tube is calculated analytically and is found to be the
same owing to the Weyl symmetry. It is suggested that the flux-tube can be
treated in quite a similar way with the Abrikosov-Nielsen-Olesen vortex in the
U(1) Abelian Higgs theory except for various types of flux-tube.


title: Effective theory of NN interactions in a separable representation

abstract:
  We consider the effective field theory of the NN system in a separable
representation. The pionic part of the effective potential is included
nonperturbatively and approximated by a separable potential. The use of a
separable representation allows for the explicit solution of the
Lippmann-Schwinger equation and a consistent renormalization procedure. The
phase shifts in the $^1S_0$ channel are calculated to subleading order.


title:
Jet Activity in t-tbar Events and Top Mass Reconstruction at Hadron
  Colliders

abstract:
  We analyse the impact of matrix-element corrections to top decays in HERWIG
on several observables related to the jet activity in t-tbar events at the
Tevatron and at the LHC. In particular, we study the effects induced by the
higher-order corrections to top decays on the top mass reconstruction using the
recently proposed J/psi+lepton final states.


title: The topological susceptibility and f_pi from lattice QCD

abstract:
  We study the topological susceptibility, chi, in QCD with two quark flavours
using the lattice field configurations recently produced by the UKQCD
collaboration. We find clear evidence for the expected suppression at small
quark mass, and examine the variation of chi with this mass. The resulting
estimate of the pion decay constant, f_pi = 105 +/- 5 +18/-10 MeV, is
consistent with the experimental value of approximately 93 MeV. We compare chi
to the large-N_c prediction and find consistency over a large range of quark
masses. The benefits of the non-perturbative action improvement scheme and the
matched lattice spacings between simulation ensembles are discussed. We compare
our results with other studies and suggest a reason why such a quark mass
dependence has not been previously seen.


title:
Beam Polarization and Spin Correlation Effects in Chargino Production
  and Decay

abstract:
  We study chargino production e^+ e^- -> chi^+_1 chi^-_1 and the subsequent
leptonic decay chi^-_1\to chi^0_1 e^- nu_e including the complete spin
correlations between production and decay. We work out the advantages of
polarizing the e^+ and e^- beams. We study in detail the polarized cross
sections, the angular distribution and the forward--backward asymmetry of the
decay electron. They can be used to determine the sneutrino mass
m_{\tilde{\nu}_e}.


title: Quintessence Axion Potential Induced by Electroweak Instanton Effects

abstract:
  Recent cosmological observations suggest the presence of small but nonzero
cosmological constant $\Lambda_{cos}^4 \simeq (2 \times 10^{-3} eV)^4$. It is
an intriguing possibility that such a small cosmological constant is supplied
by the potential energy density of an ultralight axion-like field (called as
quintessence axion). If this axion couples to the electroweak gauge fields, its
potential may be generated by the electroweak instanton effects. We calculate
the axion potential assuming the supersymmetric standard model and obtain a
surprising result that the induced energy density of the quintessence axion
field is very close to the value suggested from the observations.


title: The CQM model

abstract:
  I review a Constituent-Quark-Meson model (CQM) for heavy meson decays,
outlining its characteristics and the calculation techniques developed for it.
The strength of this effective model is that it enables to evaluate heavy meson
decay amplitudes through diagrams where the heavy mesons are attached at the
ends of loops containing heavy and light quark internal lines. The
phenomenological applications are presented in detail, trying to give a
self-contained operative picture of the model.


title:
Next-to-leading order QCD corrections to top quark spin correlations at
  hadron colliders: the reactions $q{\bar q}\to t{\bar t}(g)$

abstract:
  Future hadron collider experiments are expected to record large to huge
samples of $t\bar t$ events. The analysis of these data with respect to $t\bar
t$ spin-spin correlations requires precise predictions of the production of
these quark pairs in a general spin configuration. Therefore we have computed,
at next-to-leading order (NLO) in the QCD coupling, the spin density matrices
describing $t\bar t$ production by quark antiquark annihilation, which is the
dominant production process at the Tevatron. Moreover we have computed the
strength of the $t\bar t$ spin correlation at NLO, using various spin
quantization axes.


title: Reinterpretation of Effective Chiral Lagrangian

abstract:
  Effective tree Chiral Lagrangian is interpreted as a power series expansion
of the kinematical variables. In the presence of the strong interaction this
expansion is valid below the unitarity cut, hence in the unphysical region.
  Consequences of this reinterpretation of the Chiral Lagrangian are analysed
for the relation between K-pi and K-pipi transitions.


title: The QCD Coupling Constant

abstract:
  This paper presents a summary of the current status of determinations of the
strong coupling constant alpha_s. A detailed description of the definition,
scale dependence and inherent theoretical ambiguities is given. The various
physical processes that can be used to determine alpha_s are reviewed and
attention is given to the uncertainties, both theoretical and experimental.


title:
Sensitivity to effective electroweak couplings in single top production
  at the LHC

abstract:
  This paper has been withdrawn by the authors, due a crucial error in the
Montecarlo simulation. See hep-ph/0107112 for a correct version. If interested
in the validity of the effective-W approximation see hep-ph/0109059.


title: Astrophysics and Cosmology

abstract:
  These notes are intended as an introductory course for experimental particle
physicists interested in the recent developments in astrophysics and cosmology.
I will describe the standard Big Bang theory of the evolution of the universe,
with its successes and shortcomings, which will lead to inflationary cosmology
as the paradigm for the origin of the global structure of the universe as well
as the origin of the spectrum of density perturbations responsible for
structure in our local patch. I will present a review of the very rich
phenomenology that we have in cosmology today, as well as evidence for the
observational revolution that this field is going through, which will provide
us, in the next few years, with an accurate determination of the parameters of
our standard cosmological model.


title:
RunDec: a Mathematica package for running and decoupling of the strong
  coupling and quark masses

abstract:
  In this paper the formulae are collected which are needed for the computation
of the strong coupling constant and quark masses at different energy scales and
for different number of active flavours. All equations contain the
state-of-the-art QCD corrections up to three- and sometimes even four-loop
order. For the practical implementation {\tt Mathematica} is used and a package
containing useful procedures is provided.


title: Probing top flavour-changing neutral scalar couplings at the CERN LHC

abstract:
  Top decays into a light Higgs boson and an up or charm quark can reach
detectable levels in Standard Model extensions with two Higgs doublets or with
new exotic quarks, and in the Minimal Supersymmetric Standard Model. Using both
a standard and a neural network analysis we show that the CERN Large Hadron
Collider will give 3 sigma evidence of decays with Br(t -> Hc) >= 6.5 10^-5 or
set a limit Br(t -> Hc) <= 4.5 10^-5 with a 95% confidence level if these
decays are not observed. We also consider limits obtained from single top
production associated with a neutral Higgs boson.


title: Neutrino conversions in cosmological gamma-ray burst fireballs

abstract:
  We study neutrino conversions in a recently envisaged source of high-energy
neutrinos (E \geq 10^6 GeV), that is, in the vicinity of cosmological Gamma-Ray
Burst fireballs (GRB). We consider the effects of flavor and spin-flavor
conversions and point out that in both situations, a some what higher than
estimated high energy tau neutrino flux from GRBs is expected in new km^2
surface area under water/ice neutrino telescopes.


title: The Role of the QCD Vacuum in the Heavy-Quark Bound State Dynamics

abstract:
  The effective field theory approach allows a rigorous disentangling of high
and low energy effects in the heavy quarkonium dynamics. Focusing in particular
on the spectrum, we describe the nature of the non-perturbative effects and
discuss our present knowledge of them.


title: Status of the neutrino decay solution to the solar neutrino problem

abstract:
  We re-examine the neutrino decay solution to the solar neutrino problem in
the light of the SuperKamiokande (SK) data. For the decay solution the SK
spectrum data by its own can provide a fit comparable to the fit obtained from
the MSW solution. However when one combines the results from the total rates of
the $^{37}{Cl}$ and $^{71}{Ga}$ experiments the fit becomes much poorer.


title:
Simplification of Flavour Combinatorics in the Evaluation of Hadronic
  Processes

abstract:
  A serious computational problem in the evaluation of hadronic collision
processes is connected with the large number of partonic subprocesses included
in the calculation. These are from the quark and gluon content of the initial
hadrons, and from CKM quark mixing. For example, there are 180 subprocesses
which contribute to the $W$+2jets process, and 292 subprocesses in $W$+3jets
production at the LHC, even when quarks from only the first two generations are
taken into account.
  We propose a simple modification of the rules for evaluation of cross
sections and distributions, which avoids multiplication of channels from the
mixture of quark states. The method is based on a unitary rotation of down
quarks, thus, transporting the mixing matrix elements from vertices of Feynman
diagrams to the parton distribution functions (PDF). As a result, one can
calculate cross sections with significantly fewer subprocesses. For the example
mentioned above, with the new rules, one need evaluate only 21 and 33
subprocesses respectively. The matrix elements of the subprocesses are
calculated without quark mixing but with a modified PDF convolution which
depends on the quark mixing angle, and on the topologies of gauge invariant
classes of diagrams. The proposed method has been incorporated into the CompHEP
program and checked with various examples.


title: Parity-breaking electromagnetic interactions in thermal QED_3

abstract:
  We examine the parity violating terms generated by the box diagram in QED_3
at finite temperature. These lead to both extensive as well as non-extensive
effective actions, which have very distinct behavior in the long wavelength and
static limits. We discuss a large gauge Ward identity for the leading terms in
the static limit, whose solution coincides with the effective action proposed
earlier.


title: Gluon and quark distributions in large N_c QCD: theory vs. phenomenology

abstract:
  We present the QCD analysis of the behavior of quark and gluon distributions
in the limit of a large number of colors N_c. We show that the results agree
qualitatively with the phenomenological data. In particular we draw attention
to the fact that the polarized gluon distribution is suppressed at large N_c
compared to the unpolarized one.


title:
Three Inequivalent Mass-Degenerate Majorana Neutrinos and a Model of
  Their Splitting for Neutrino Oscillations

abstract:
  The mass matrix of three Majorana neutrinos of equal mass is not necessarily
proportional to the identity matrix, but expressible in terms of two angles and
one phase. We discuss how such a mass matrix may be stable or unstable against
radiative corrections. We then propose a model with additional explicit
breaking of the threefold degeneracy to account for the atmospheric neutrino
data, while the radiative breaking explains the solar neutrino data, using the
large-angle Mikheyev-Smirnov-Wolfenstein solution. Our model requires a nonzero
effective $\nu_e$ mass for neutrinoless double beta decay close to the present
experimental upper limit of 0.2 eV.


title: On the miracle of the Coleman-Glashow and other baryon mass formulas

abstract:
  Due to a new measurement of the Xi(0) mass,the Coleman-Glashow formula for
the baryon octet e.m. masses (derived using unbroken SU(3) is satisfied to an
extraordinary level of precision.The same unexpected precision exists for the
Gell-Mann Okubo formula and for its octet-decuplet extension
(G.Morpurgo,Phys.Rev.Lett. 68(1992)139).We show that the old question "why do
they work so well?" is now answered by the general parameterization method.


title:
Spontaneous Scale Symmetry Breaking in 2+1-Dimensional QED at Both Zero
  and Finite Temperature

abstract:
  A complete analysis of dynamical scale symmetry breaking in 2+1-dimensional
QED at both zero and finite temperature is presented by looking at solutions to
the Schwinger-Dyson equation. In different kinetic energy regimes we use
various numerical and analytic techniques (including an expansion in large
flavour number). It is confirmed that, contrary to the case of 3+1 dimensions,
there is no dynamical scale symmetry breaking at zero temperature, despite the
fact that chiral symmetry breaking can occur dynamically. At finite
temperature, such breaking of scale symmetry may take place.


title: Supersymmetry Breaking, Fermion Masses and a Small Extra Dimension

abstract:
  We present a supersymmetric model in which the observed fermion masses and
mixings are generated by localizing the three generations of matter and the two
Higgs fields at different locations in a compact extra dimension. Supersymmetry
is broken by the shining method and the breaking is communicated to standard
model fields via gaugino mediation. Quark masses, CKM mixing angles and the mu
term are generated with all dimensionless couplings of O(1). All dimensionful
parameters are of order the five-dimensional Planck scale except for the size
of the extra dimension which is of order the GUT scale. The superpartner
spectrum is highly predictive and is found to have a neutralino LSP over a wide
range of parameter space. The resulting phenomenology and interesting
extensions of the model are briefly discussed.


title:
Exact non-factorizable O(alpha_s g^2) two-loop contribution to Z -> b
  bbar

abstract:
  For Z -> b bbar, we calculate all the two-loop top dependent Feynman graphs,
which have mixed QCD and electroweak contributions that are not factorizable.
For evaluating the graphs, without resorting to a mass expansion, we apply a
two-loop extension of the one-loop Passarino-Veltman reduction. This is an
analytic-numerical method, which first converts all diagrams into a set of ten
standard scalar functions, and then integrates them numerically over the
remaining Feynman parameters, with rapid convergence and high accuracy. We
discuss the treatment of infrared singularities within our methods. We do not
resort to unitarity cuts of two-point functionsfor calculating decay rates;
these are useful only to obtain an inclusive rate. For this reason,
experimental cuts and the experimental infrared energy resolution can be
implemented in our calculation, once the corresponding one-loop gluon
Bremsstrahlung process is added to this calculation.


title: Dark Matter and Cosmic Strings in Particle Models

abstract:
  In this talk, I will discuss the mechanism of nonthermal production of the
neutralino cold dark matter from the decay of cosmic strings and the embedded
defects, the $\pi$ and $\eta^\prime$ strings in the strong interaction sector
of the standard model.


title: Inelastic electroproduction of $\eta_c$ at ep colliders

abstract:
  Using the nonrelativistic QCD factorization formalism, we calculate the
electroproduction cross sections of $\eta_c$ in ep collisions, including the
contribution from both the transverse photon and the longitudinal photon. For
this process the color-singlet contribution vanishes up to the next to leading
order perturbative QCD calculations. 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 heavy quark spin symmetry, and the latter can be determined from
the direct production of $J/\psi$ at large transverse momentum at the Fermilab
Tevatron. The measurement of this process at DESY HERA can be viewed as another
independent test for the color-octet production mechanism


title: Matter effects for `just so' oscillations

abstract:
  We study the effect of the matter term on the evolution of the solar
neutrinos when the neutrino parameters are those of the `just-so' case. The
extreme non-adiabatic effects at the edge of the sun reduce the expression for
the survival probability in the just-so case to that of the vacuum case. This
conclusion is independent of the width of the extreme non-adiabatic region,
which is a function of the density profile of the sun beyond $r > 0.9 R_s$.
However, in its propagation, neutrino encounters regions of moderate
(non-extreme) non-adiabticity. Neutrino traversal through these regions give
corrections to the survival probability which are profile dependent.


title: QCD Corrections to Neutralino-Nucleon Scattering

abstract:
  We calculate the dominant loop corrections from both standard and
supersymmetric QCD to the effective coupling of neutralinos to nucleons. The
potentially largest corrections come from gluino-squark loop contributions to
the Higgs boson couplings to quarks; these corrections also affect the leading
spin-independent squark exchange contribution. Ordinary QCD corrections to the
effective coupling of CP-even Higgs bosons to two gluons are also sizable. For
large $\tanb$ values, i.e. in the region of parameter space probed by current
and near-future direct Dark-Matter search experiments, the total corrections
can exceed a factor of three.


title:
Anatomy of the differential gluon structure function of the proton from
  the experimental data on F_2p

abstract:
  The use of the differential gluon structure function of the proton ${\cal
F}(x,Q^{2})$ introduced by Fadin, Kuraev and Lipatov in 1975 is called upon in
many applications of small-x QCD. We report here the first determination of
${\cal F}(x,Q^{2})$ from the experimental data on the small-x proton structure
function $F_{2p}(x,Q^{2})$. We give convenient parameterizations for ${\cal
F}(x,Q^{2})$ based partly on the available DGLAP evolution fits (GRV, CTEQ &
MRS) to parton distribution functions and on realistic extrapolations into soft
region. We discuss an impact of soft gluons on various observables. The
x-dependence of the so-determined ${\cal F}(x,Q^{2})$ varies strongly with Q^2
and does not exhibit simple Regge properties. None the less the hard-to-soft
diffusion is found to give rise to a viable approximation of the proton
structure function F_{2p}(x,Q^2) by the soft and hard Regge components with
intercepts \Delta_{soft}=0 and \Delta_{hard}\sim 0.4.


title: Low Energy Theory for 2 flavors at High Density QCD

abstract:
  We construct the effective Lagrangian describing the low energy excitations
for Quantum Chromodynamics with two flavors at high density. The non-linear
realization framework is employed to properly construct the low energy
effective theory. The light degrees of freedom, as required by 't Hooft anomaly
conditions, contain massless fermions which we properly include in the
effective Lagrangian. We also provide a discussion of the linearly realized
Lagrangian.


title: Determination of the pattern of neutrino masses at a Neutrino Factory

abstract:
  We study the precision to which the sign of \delta m_{32}^2 can be determined
at a neutrino factory, as a function of stored energies and baselines. This is
done by simultaneously fitting the channels \nu_\mu \to \nu_\mu$, \bar\nu_e \to
\bar\nu_\mu from \mu^- decays and the channels \bar\nu_\mu \to \bar\nu_\mu,
\nu_e \to \nu_\mu from \mu^+ decays. We investigate the sensitivity reach in
the parameter \sin^22\theta_{13} to which one can determine the sign of \delta
m_{32}^2 to 3 standard deviations as a function of the baseline length and
magnitude of \delta m_{32}^2 with a 20 GeV muon storage ring. We find that for
baselines longer than 2000 km, the sign of \delta m^2_{32} can be determined
for \sin^22\theta_{13} down to the 10^{-3} level with 10^{20} decays of 20 GeV
muons.


title: Binding energy corrections in positronium decays

abstract:
  Positronium annihilation amplitudes that are computed by assuming a
factorization approximation with on-shell intermediate leptons, do not exhibit
good analytical behavior. We propose an ansatz which allows to include binding
energy corrections and obtain the correct analytical and gauge invariance
behavior of these QED amplitudes. As a consequence of these non-perturbative
corrections, the parapositronium and orthopositronium decay rates receive
corrections of order alpha^4 and alpha^2, respectively. These new corrections
for orthopositronium are relevant in view of a precise comparison between
recent theoretical and experimental developments. Implications are pointed out
for analogous decays of quarkonia .


title: The Superpartner Spectrum of Gaugino Mediation

abstract:
  We compute the superpartner masses in a class of models with gaugino
mediation (or no-scale) boundary conditions at a scale between the GUT and
Planck scales. These models are compelling because they are simple, solve the
supersymmetric flavor and CP problems, satisfy all constraints from colliders
and cosmology, and predict the superpartner masses in terms of very few
parameters. Our analysis includes the renormalization group evolution of the
soft-breaking terms above the GUT scale. We show that the running above the GUT
scale is largely model independent and find that a phenomenologically viable
spectrum is obtained.


title: Light-Cone Wavefunctions and the Intrinsic Structure of Hadrons

abstract:
  The light-cone Fock-state representation of QCD encodes the properties of a
hadrons in terms of frame-independent wavefunctions. A new type of jet
production reaction, "self-resolving diffractive interactions" can provide
direct information on the light-cone wavefunctions of hadrons in terms of their
quark and gluon degrees of freedom as well as the composition of nuclei in
terms of their nucleon and mesonic degrees of freedom. The relation of the
intrinsic sea to the light-cone wavefunctions is discussed. The decomposition
of light-cone spin is illustrated for the quantum fluctuations of an electron.