title: Solving a Coupled Set of Truncated QCD Dyson-Schwinger Equations

abstract:
  Truncated Dyson-Schwinger equations represent finite subsets of the equations
of motion for Green's functions. Solutions to these non-linear integral
equations can account for non-perturbative correlations. A closed set of
coupled Dyson-Schwinger equations for the propagators of gluons and ghosts in
Landau gauge QCD is obtained by neglecting all contributions from irreducible
4-point correlations and by implementing the Slavnov-Taylor identities for the
3-point vertex functions. We solve this coupled set in an one-dimensional
approximation which allows for an analytic infrared expansion necessary to
obtain numerically stable results. This technique, which was also used in our
previous solution of the gluon Dyson-Schwinger equation in the Mandelstam
approximation, is here extended to solve the coupled set of integral equations
for the propagators of gluons and ghosts simultaneously. In particular, the
gluon propagator is shown to vanish for small spacelike momenta whereas the
previoulsy neglected ghost propagator is found to be enhanced in the infrared.
The running coupling of the non-perturbative subtraction scheme approaches an
infrared stable fixed point at a critical value of the coupling, alpha_c
approximately 9.5.


title:
Universal $\tau_{1/2}(y)$ Isgur-Wise Function at the Next-to-Leading
  Order in QCD Sum Rules

abstract:
  We use QCD sum rules, in the framework of the Heavy Quark Effective Theory,
to calculate the universal form factor $\tau_{1/2}(y)$ parameterizing the
semileptonic transitions $B \to D_0 \ell \bar \nu$, $B \to D_1^* \ell \bar
\nu$, where $D_0$ and $D^*_1$ are the members of the excited charmed doublet
with $J^P=(0^+_{1/2},1^+_{1/2})$. We include two-loop corrections in the
perturbative contribution to the sum rule, and present a complete
next-to-leading order result. As a preliminary part of our analysis we also
compute, up to order $\alpha_s$, the leptonic constant $F^+$ of the doublet
$D_0$, $D_1^*$. Finally, we discuss the phenomenological implications of this
calculation.


title: Vorton Formation

abstract:
  In this paper we present the first analytic model for vorton formation. We
start by deriving the microscopic string equations of motion in Witten's
superconducting model, and show that in the relevant chiral limit these
coincide with the ones obtained from the supersonic elastic models of Carter
and Peter. We then numerically study a number of solutions of these equations
of motion and thereby suggest criteria for deciding whether a given
superconducting loop configuration can form a vorton. Finally, using a recently
developed model for the evolution of currents in superconducting strings we
conjecture, by comparison with these criteria, that string networks formed at
the GUT phase transition should produce no vortons. On the other hand, a
network formed at the electroweak scale can produce vortons accounting for up
to 6% of the critical density. Some consequences of our results are discussed.


title: Broken conformal invariance and spectrum of anomalous dimensions in QCD

abstract:
  Employing the operator algebra of the conformal group and the conformal Ward
identities, we derive the constraints for the anomalies of dilatation and
special conformal transformations of the local twist-2 operators in Quantum
Chromodynamics. We calculate these anomalies in the leading order of
perturbation theory in the minimal subtraction scheme. From the conformal
consistency relation we derive then the off-diagonal part of the anomalous
dimension matrix of the conformally covariant operators in the two-loop
approximation of the coupling constant in terms of these quantities. We deduce
corresponding off-diagonal parts of the Efremov-Radyushkin-Brodsky-Lepage
kernels responsible for the evolution of the exclusive distribution amplitudes
and non-forward parton distributions in the next-to-leading order in the
flavour singlet channel for the chiral-even parity-odd and -even sectors as
well as for the chiral-odd one. We also give the analytical solution of the
corresponding evolution equations exploiting the conformal partial wave
expansion.


title:
Manifestations of R-Parity Violation in Ultrahigh-Energy Neutrino
  Interactions

abstract:
  Supersymmetric couplings that do not respect R-parity can induce significant
changes in the interaction rates of ultrahigh-energy neutrinos through the
direct-channel production of superpartner resonances, and can provide new
sources of extremely energetic tau-leptons. We analyze the possible observable
consequences of R-parity violating transitions in large-volume neutrino
telescopes.


title: Precise Estimates of High Orders in QCD

abstract:
  I review the recent work on obtaining precise estimates of higher-order
corrections in QCD and field theory.


title: Baryon Magnetic Moments in a QCD-based Quark Model with loop corrections

abstract:
  We study meson loop corrections to the baryon magnetic moments starting from
a QCD-based quark model derived earlier in a quenched approximation to QCD. The
model reproduces the standard quark model with extra corrections for the
binding of the quarks. The loop corrections are necessary to remove the
quenching. Our calculations use heavy baryon perturbation theory with chiral
baryon-meson couplings and a form factor characterizing the structure of
baryons as composite particles. The form factor reflects soft wave function
effects with characteristic momenta $\approx 400$ MeV, well below the usual
chiral cutoff of $\approx 1$ GeV. The resulting model involves only three
parameters, the quark moments $\mu_u$ and $\mu_s$ and a parameter $\lambda$
that sets the momentum scale in the wavefunctions. We find that this approach
substantially improves the agreement between the theoretical and experimental
values of the octet baryon magnetic moments, with an average difference between
the theoretical and experimental moments of 0.05$\mu_N$. An extension to the
decuplet states using the same input predicts a moment of 1.97 $\mu_N$ for the
$\Omega^-$ hyperon, in excellent agreement with the measured moment of
$2.02\pm0.05 \mu_N$.


title:
Decuplet baryon magnetic moments in a QCD-based quark model beyond
  quenched approximation

abstract:
  We study the decuplet baryon magnetic moments in a QCD-based quark model
beyond quenched approximation. Our approach for unquenching the theory is based
on the heavy baryon perturbation theory in which the axial couplings for baryon
- meson and the meson-meson-photon couplings from the chiral perturbation
theory are used together with the QM moment couplings. It also involves the
introduction of a form factor characterizing the structure of baryons
considered as composite particles. Using the parameters obtained from fitting
the octet baryon magnetic moments, we predict the decuplet baryon magnetic
moments. The $\Omega^-$ magnetic moment is found to be in good agreement with
experiment: $\mu_{\Omega^-}$ is predicted to be $-1.97 \mu_N$ compared to the
experimental result of ($-$2.02 $\pm$ 0.05) $\mu_N$.


title: Where is the jet quenching in Pb+Pb collisions at 158 AGeV?

abstract:
  Because of the rapidly falling particle spectrum at large $p_T$ from jet
fragmentation at the CERN SPS energy, the high-$p_T$ hadron distribution should
be highly sensitive to parton energy loss inside a dense medium as predicted by
recent perturbative QCD (pQCD) studies. A careful analysis of recent data from
CERN SPS experiments via pQCD calculation shows little evidence of energy loss.
This implies that either the life-time of the dense partonic matter is very
short or one has to re-think about the problem of parton energy loss in dense
matter. The hadronic matter does not seem to cause jet quenching in $Pb+Pb$
collisions at the CERN SPS. High-$p_T$ two particle correlation in the
azimuthal angle is proposed to further clarify this issue.


title: Dimensionally regularized study of nonperturbative quenched QED

abstract:
  We study the dimensionally regularized fermion propagator Dyson-Schwinger
equation in quenched nonperturbative QED. We work in arbitrary covariant gauge
and perform nonperturbative renormalization numerically. The nonperturbative
fermion propagator is solved in D = 4 - 2 * epsilon dimensional Euclidean space
for a large number of values of epsilon. Results for D=4 dimensions are then
obtained by extrapolation to epsilon = 0. Here we present results using the
Curtis-Penningon fermion-photon proper vertex for two values of the coupling,
namely alpha=0.6 and alpha=1.5, and compare these to previous studies employing
a modified ultraviolet cut-off regularization. The results using the two
different regularizations are found to agree to within the numerical precision
of the present calculations.


title:
Cross section of high-energy photon splitting in the electric fields of
  heavy atoms

abstract:
  Various differential cross sections of high-energy photon splitting in the
electric fields of heavy atoms are calculated exactly in the parameter \al. The
consideration is based on the quasiclassical approach applicable for small
angles between all photon momenta. The expressions obtained are valid for
arbitrary transverse momenta of final photons . The detailed investigation of
the process is performed taking into account the effect of screening . The
exact cross section turns out to be noticeably smaller than the result obtained
in the Born approximation.


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

abstract:
  A truncation scheme for the Dyson-Schwinger equations of QCD in Landau gauge
is presented which implements the Slavnov-Taylor identities for the 3-point
vertex functions. Neglecting contributions from 4-point correlations such as
the 4-gluon vertex function and irreducible scattering kernels, a closed system
of equations for the propagators is obtained. For the pure gauge theory without
quarks this system of equations for the propagators of gluons and ghosts is
solved in an approximation which allows for an analytic discussion of its
solutions in the infrared: The gluon propagator is shown to vanish for small
spacelike momenta whereas the ghost propagator is found to be infrared
enhanced. The running coupling of the non-perturbative subtraction scheme
approaches an infrared stable fixed point at a critical value of the coupling,
alpha_c approximately 9.5. The results for the propagators obtained here
compare favorably with recent lattice calculations.


title: Multi-pion correlations in high energy collisions

abstract:
  Any-order pion inclusive distribution for a chaotic source in high energy
collisions are given which can be used in both theory and experiment to analyze
any-order pion interferometry. Multi-pion correlations effects on two-pion and
three-pion interferometry are discussed.


title: On the phenomenology of a Z' coupling only to third-family fermions

abstract:
  The phenomenology of an additional U(1) neutral gauge boson Z' coupled to the
third family of fermions is discussed. One might expect such a particle to
contribute to processes where taus, b and t quarks are produced. Precision data
from LEP1 put severe constraints on the mixing and heavy-boson mass. We find
that the effects of such a particle could not be observed at hadronic
colliders, be it at the Tevatron or the LHC, because of the QCD background. At
LEP2 and future e^+e^- linear colliders, one could instead hope to observe such
effects, in particular for b\bar b final states.


title: $\eta\gamma Z$ anomaly from the $\eta-->\gamma\mu+\mu-$ decay

abstract:
  We show that the $\eta\gamma Z$ anomaly can be measured by analysing
parity-violating effects in the $\eta-->\gamma\mu+\mu-$ decay. In this sense,
we find that the longitudinal polarization of the outgoing $\mu^+$ is an
appropriate observable to be considered in future high-statistics $\eta$
factories. The effect is expected to lie in the range $10^{-5}-10^{-6}$ in the
Standard Model.


title: SU(3) breaking and Hidden Local Symmetry

abstract:
  We study the various existing implementations of SU(3) breaking in the Hidden
Local Symmetry model for the low energy hadronic sector following a mechanism
originally proposed by Bando, Kugo and Yamawaki (BKY). We pay particular
attention to hermiticity and current conservation. Following this, we present a
new method for including symmetry breaking effects which preserves the BKY mas
s relation among vector mesons. Symmetry breaking (SB) necessarily requires a
transformation of the pseudoscalar fields, which, following BKY, we refer to a
s field renormalization. We examine the consequences of propagating this throug
h all Lagrangian terms including the anomalous ones. We thus explore the
consequences of these various SB schemes for both charged and neutral
pseudoscalar decay constants as measured in weak and anomalous decays
respectively.


title: Unstable Higgs Particle and the Equivalence Theorem

abstract:
  We consider the subtleties involved in the application of the Equivalence
Theorem to the decay of an unstable Higgs particle. This is formally justified
from consideration of unitarity and resonant elastic scattering of the stable
decay products. By explicit perturbative calculation we find that the imaginary
parts of the one-loop amplitudes for that decay are in agreement with the
Equivlence Theorem only when one includes the imaginary parts generated by
evaluatuing the tree-level amplitudes at the complex on-shell value of the
four-momentum squared of the unstable particle.


title:
Two body decays of the $b$-quark: Applications to direct CP violation,
  searches for electro-weak penguins and new physics

abstract:
  A systematic experimental search for two-body hadronic decays of the b-quark
of the type b to quark + meson is proposed. These reactions have a well defined
experimental signature and they should be theoretically cleaner compared to
exclusive decays. Many modes have appreciable branching ratios and partial rate
asymmetries may also be quite large (about 8-50%) in several of them. In a few
cases electroweak penguins appear to be dominant and may be measurable. CP
violating triple correlation asymmetries provide a clean test of the Standard
Model.


title: Proton Structure Functions from Chiral Dynamics and QCD Constraints

abstract:
  The spin fractions and deep inelastic structure functions of the proton are
analyzed using chiral field theory involving Goldstone bosons. A detailed
comparison with recent chiral models sheds light on their successful
description of the spin fractions of the proton as being due to neglecting
helicity non-flip chiral transitions. This approximation is valid for zero mass
quarks but not for constituent quarks. Since the chiral spin fraction models
with the pure spin-flip approximation reproduce the measured spin fractions of
the proton, axialvector constituent-quark-Goldstone boson coupling is found to
be inconsistent with the proton spin data. Initial quark valence distributions
are then constructed using quark counting constraints at Bjorken $x \to 1$ and
Regge behavior at $x \to 0$. Sea quark distributions predicted by chiral field
theory on this basis have correct order of magnitude and shape. The spin
fractions agree with the data.


title: Spontaneous CP Violation

abstract:
  In this talk I begin with some general discussion of the history of CP
violation, then move on to aspects of the aspon model including the production
of new particles at LHC, implications for B decay, generalized Cabibbo mixing
and a reevaluation of kaon CP violation. Finally there is a summary.


title: The weak isospin space

abstract:
  The Clifford pentad of the 4X4 matrices defines the 5-dimensional space. Each
weak isospin transformation divides an electron on two components, which
scatter in the 2-dimensional subspace and which indiscernible in the orthogonal
3-dimensional subspace. PACS 12.15.-y


title: Quark and Gluon Orbital Angular Momentum and Spin in Hard Processes

abstract:
  We suggest a method of constructing gauge invariant quark and gluon
distributions that describe an abstract QCD observable and apply this method to
analyze angular momentum of a hadron. In addition to the known quark and gluon
polarized structure functions, we obtain gauge invariant distributions for
quark and gluon orbital angular momenta, and consider some basic properties of
these distributions and their moments.


title: New Dimensions at a Millimeter to a Fermi and Superstrings at a TeV

abstract:
  Recently, a new framework for solving the hierarchy problem has been proposed
which does not rely on low energy supersymmetry or technicolor. The
gravitational and gauge interactions unite at the electroweak scale, and the
observed weakness of gravity at long distances is due the existence of large
new spatial dimensions. In this letter, we show that this framework can be
embedded in string theory. These models have a perturbative description in the
context of type I string theory. The gravitational sector consists of closed
strings propagating in the higher-dimensional bulk, while ordinary matter
consists of open strings living on D3-branes. This scenario raises the exciting
possibility that the LHC and NLC will experimentally study both ordinary
aspects of string physics such as the production of narrow Regge-excitations of
all standard model particles, as well more exotic phenomena involving strong
gravity such as the production of black holes. The new dimensions can be probed
by events with large missing energy carried off by gravitons escaping into the
bulk. We finally discuss some important issues of model building, such as
proton stability, gauge coupling unification and supersymmetry breaking.


title: Effective theories with maximal analyticity

abstract:
  In this paper (second in the series) we study the properties of tree-level
binary amplitudes of the infinite-component effective field theory of strong
interaction obeying the requirements of quark-hadron duality and maximal
analyticity. In contrast to the previous paper, here we derive the results
following from less restrictive --- Regge-like --- boundedness conditions. We
develop the technique of Cauchy's forms in two variables and show the
string-like structure of a theory. Next, we derive the full set of bootstrap
constraints for the resonance parameters in (\pi,K) system. Numerical test
shows: (1) those constraints are consistent with data on well established
vector resonances; (2) two light broad resonances -- sigma- and kappa-mesons --
are needed to saturate sum rules following from Chiral symmetry and
analyticity. As a by-product we obtain expressions for the parameters of Chiral
expansions and give corresponding estimates.


title:
Three flavor neutrino oscillation analysis of the Superkamiokande
  atmospheric neutrino data

abstract:
  Superkamiokande atmospheric neutrino data for 535 days are analyzed in the
framework of three flavor oscillations with mass hierarchy. It is shown that
the best fit point is very close to the pure maximal
$\nu_\mu\leftrightarrow\nu_\tau$ case and $\Delta m^2 \simeq 7\times10^{-3}$
eV$^2$. The allowed region at 90 %CL is given and the implications to the long
baseline experiments are briefly discussed.


title:
Cancellation of $1/m_Q$ Corrections to the Inclusive Decay Width of a
  Heavy Quark

abstract:
  We consider the infrared sensitivity of the inclusive heavy quark decay width
in perturbation theory. It is shown by explicit calculations to the second loop
order (when the non-abelian nature of the QCD interactions first become
apparent) that all infrared sensitive terms to logarithmic and linear accuracy
cancel when the decay width is expressed in terms of the short distance mass.
This in turn implies the absense of any non perturbative $1/m_Q$ power
corrections to the decay width. The cancellation is shown algebraically at the
level of the Feynman integrands without any use of an explicit infrared cutoff.
This result is in accord with the implications of the KLN theorem.


title: An Explicit Model of Quark Mass Matrix

abstract:
  A physical model which describes the CKM matrix is analyzed. The elements of
such a matrix are field-strength renormalization factors. Each column gives the
probability amplitude for the field operators of the coupled Lagrangian to
create a one-particle eigenfunction of definite energy. The total conserved
charge is the sum of the flavor charges which are not conserved separately.


title: Color-Flavor Locking and Chiral Symmetry Breaking in High Density QCD

abstract:
  We propose a symmetry breaking scheme for QCD with three massless quarks at
high baryon density wherein the color and flavor SU(3)_color times SU(3)_L
times SU(3)_R symmetries are broken down to the diagonal subgroup
SU(3)_{color+L+R} by the formation of a condensate of quark Cooper pairs. We
discuss general properties that follow from this hypothesis, including the
existence of gaps for quark and gluon excitations, the existence of
Nambu-Goldstone bosons which are excitations of the diquark condensate, and the
existence of a modified electromagnetic gauge interaction which is unbroken and
which assigns integral charge to the elementary excitations. We present
mean-field results for a Hamiltonian in which the interaction between quarks is
modelled by that induced by single-gluon exchange. We find gaps of order 10-100
MeV for plausible values of the coupling. We discuss the effects of nonzero
temperature, nonzero quark masses and instanton-induced interactions on our
results.


title: Energy dependence of the survival probability of large rapidity gap

abstract:
  The energy dependence for the survival probability of large rapidity gaps
(LRG) $< \mid S \mid^2 >$, is calculated in an Eikonal model assuming a
Gaussian opacity. The parameters determining $< \mid S \mid^2 >$ are evaluated
directly from experimental data, without further recourse to models. We find
that $< \mid S \mid^2 >$ decreases with increasing energy, in line with recent
results for LRG dijet production at the Tevatron.


title:
The Running BFKL: Precocious Asymptopia for Charm and the $dF_{2}/d\log
  Q^2$ - Puzzle

abstract:
  The running BFKL equation gives rise to a series of moving poles in the
complex $j$-plane. The first nodes for all subleading solutions (color dipole
cross sections) accumulate at $r_1\sim 0.1 fm$.Therefore the processes
dominated by the dipole sizes $r\sim r_1 $ are free of subleading BFKL
corrections. An example - the leptoproduction of charm. The calculated
$F_2^{cc}$ is exhausted by the leading BFKL pole and gives a perfect
description of the experimental data. The logarithmic slope of the subleading
structure functions, $dF_2^{(n)}/d\log Q^2$, at small $Q^2$ is small compared
to $dF_2^{(0)}/d\log Q^2$ due to the presence of nodes. This observation
provides an explanation for the observed $x$/$Q^2$ dependence of the derivative
of the proton structure function $dF_2/d\log Q^2$.


title: Forward Cone in Exclusive Heavy Vector Meson Production

abstract:
  The color dipole gBFKL phenomenology of a diffraction cone for photo- and
electroproduction $\gamma^{*}N \to VN$ of heavy vector mesons (charmonium &
bottonium) at HERA and in fixed target experiments is presented. A substantial
shrinkage of the diffraction cone from the CERN/FNAL to the HERA range of
c.m.s. energy $W$ is predicted. The $Q^{2}$-controlled selectivity to the color
dipole size (scanning phenomenon) is shown to lead to a decrease of the
diffraction slope with $Q^{2}$ (which is supported by the available
experimental data). An approximate flavor independence of the diffraction slope
in the scaling variable $Q^{2}+m_{V}^{2}$ is shown to hold.


title: B_c -> l nu gamma decay in light cone QCD

abstract:
  The radiative B_c -> l nu gamma decay is investigated in the Standard Model
in framework of the light cone QCD. The transition form factors and decay width
are calculated. A comparison of light cone QCD and constituent quark model
predictions on these quantities is presented.


title: Flavor Asymmetry of the Sea Quarks in the Baryon Octet

abstract:
  We show that the chiral $SU(n)\otimes SU(n)$ flavor symmetry on the
null-plane severely restricts the sea quarks in the baryon octet. It predicts
large asymmetry for the light sea quarks $(u,d,s)$, and universality and
abundance for the heavy sea quarks. Further it is shown that existence of the
heavy sea quarks constrained by the same symmetry reduces the theoretical value
of the Ellis-Jaffe sum rule substantially.


title: On the cosmological domain wall problem in supersymmetric models

abstract:
  Many models for dynamical supersymmetry breaking have the domain wall
solution of the Kovner-Shifman type and therefore contain the potential
cosmological domain wall problem.We show that the degeneracy of the vacua is
lifted in any model in which the cosmological constant is fine-tuned to zero
through an explicit $Z_{n}^{R}$ symmetry breaking constant in the
superpotential. In this respect, we do not have to add unnatural
non-renormalizable terms which explicitly break the symmetry. We also discuss
the conditions for the safe decay of the walls for several concrete examples.


title:
Shadowing in neutrino deep inelastic scattering and the determination of
  the strange quark distribution

abstract:
  We discuss shadowing corrections to the structure function $F_2$ in neutrino
deep-inelastic scattering on heavy nuclear targets. In particular, we examine
the role played by shadowing in the comparison of the structure functions $F_2$
measured in neutrino and muon deep inelastic scattering. The importance of
shadowing corrections in the determination of the strange quark distributions
is explained.


title: Gravitino Overproduction through Moduli Decay

abstract:
  We derive cosmological constraints on the masses of generic scalar fields
which decay only through gravitationally suppressed interactions into unstable
gravitinos and ordinary particles in the supersymmetric standard model. For the
gravitino mass 100GeV-1TeV, the scalar masses should be larger than 100TeV to
keep the success of big-bang nucleosynthesis if no late-time entropy production
dilutes the gravitino density.


title:
K^+\to\pi^+\nu\bar{\nu} with four generations and its effects on
  unitarity triangle

abstract:
  We analyze in the four-generation model the first measurement of the
branching ratio of rare kaon decay K^+\to\pi^+\nu\bar{\nu}, using the
constraints from \Delta m_K, \epsilon_K, B_d-\bar{B_d} mixing, \Gamma (b\to
s\gamma), B_s-\bar{B_s} mixing, D^0-\bar{D^0} mixing,
B(K_L\to\pi^0\nu\bar{\nu}) and B(K_L\to\mu\bar{\mu}), and study its effects on
the unitarity triangle. With the results of searching for the maximum mixing of
the fourth generation, we predict that D^0-\bar{D^0} mixing \Delta m_D and the
branching ratio of "direct" CP-violating decay process K_L\to\pi^0\nu\bar{\nu}
could attain the values 1-2 orders of magnitude larger than the predictions of
the Standard Model.


title:
Multi-pion Bose-Einstein correlations in high energy heavy-ion
  collisions

abstract:
  Multi-pion correlations and wavepacket size effects on the pion multiplicity
distribution, pion momentum distribution and two-pion interferometry are
studied. It is shown that multi-pion Bose-Einstein correlations and the
wavepacket size cause an abundance of pions at low momentum, increase the mean
pion multiplicity and decrease both the apparent radius of the source and the
coherent source parameter derived from two-pion interferometry.


title: Particle Diffraction at High Energies

abstract:
  A brief ideological and historical review of problems of high energy
diffractive scattering is given.


title:
Deep inelastic ratio $R=\sigma_{L}/\sigma_{T}$ and the possible
  existence of scalar partons in the nucleon

abstract:
  We have performed several fits to find the ratio $R=\sigma_{L}/\sigma_{T}$ in
different phenomenological models. Our fits seem to leave no room for possible
admixture of scalar partons inside the nucleon.


title:
Model independent determination of the shape function for inclusive B
  decays and of the structure functions in DIS

abstract:
  We present a method to compute, by numerical simulations of lattice QCD, the
inclusive semileptonic differential decay rates of heavy hadrons and the
structure functions which occur in deep inelastic scattering. The method is
based on first principles and does not require any model assumption. It allows
the prediction of the differential rate in B semileptonic decays for values of
the recoiling hadronic mass W ~ sqrt(M_B Lambda_QCD), which is in the relevant
region to extract |V_ub| from the end-point of the lepton spectrum in inclusive
decays.


title:
Indirect CP violation in an electroweak SU(2)left x U(1) gauge theory of
  chiral mesons

abstract:
  Indirect CP violation is analyzed in the framework of the electroweak gauge
theory of J=0 mesons proposed in ref.[1], in which they transform like
composite fermion-antifermion operators by the chiral U(N)left x U(N)right
group and by the SU(2)left x U(1) gauge group of the Glashow-Salam-Weinberg
model. It is shown that, in this model where, in particular, mass terms can be
introduced for the mesons themselves, and unlike what happens in the standard
model for fermions: - electroweak mass eigenstates can differ from CP
eigenstates even in the case of two generations; - the existence of a complex
entry in the mixing matrix for the constituent fermions is no longer a
sufficient condition for indirect CP violation to occur at the mesonic level.


title:
Simple Mechanism of Softening Structure Functions at Low Transverse
  Momentum Region

abstract:
  The relevance of the dipole configurations of quarks in forming nucleus
structure functions is discussed. It is shown that a radiation generated by
dipole configurations while moving relativistically along their axises is
described by distributions which are finite and infrared stable in low
transverse momentum region. It is argued that there is an exponential
transition to the perturbative regime of large transverse momenta and its power
is defined by the distance between the dipole charges in its rest frame
$m^{-1}_\pi$.


title: Poissonian limit of soft gluon multiplicity

abstract:
  It is shown that the gluons produced with small transverse momenta $k_\perp$
inside a jet ($k_\perp <k_\perp^{cut}$, $k_\perp^{cut} \to 0$) are
independently emitted from the primary parton, as QCD coherence suppresses
their showering. Consequently, the low $k_{\perp}$ gluons follow a Poisson
distribution, very much like the soft photons radiated by a charged particle in
QED. On the contrary, the distribution of gluons with limited absolute momenta
$|\vec{k} | <k^{cut}$ remains non-Poissonian even for small $k^{cut}$. It will
be interesting to find out to what extent this perturbative prediction for
partons survives the hadronization process.


title:
Nucleosynthesis constraints on massive, stable, strongly interacting
  particles

abstract:
  We find constraints on heavy, stable, strongly interacting massive particles
(X) from searches for anomalous nuclei containing them, formed during
primordial nucleosynthesis. Using existing data, we obtain a limit on the
abundance ratio $C_X\equiv n_X/n_B$ in the range of $3\times 10^{-8}$ to
$3\times 10^{-13}$ for masses up to 10 TeV if the $X-N$ interaction is
sufficiently strong to bind in low Z nuclei. We also find a rough lower limit
on the $X-N$ interaction that implies binding in nuclei with $A\geq 200$ over
much of the $M_X$ range of interest, and address the relative abundance of such
anomalous nuclei on Earth.


title: Four-Neutrino Mixing and Big-Bang Nucleosynthesis

abstract:
  We investigate the Big-Bang Nucleosynthesis constraints on neutrino mixing in
the framework of the two four-neutrino schemes that are favored by the results
of neutrino oscillation experiments. We discuss the implications of these
constraints for terrestrial short and long-baseline neutrino oscillation
experiments and we present some possibilities of testing them in these
experiments. In particular, we show that from the Big-Bang Nucleosynthesis
constraints it follows that the nu(mu)->nu(tau) transition is severely
suppressed in short-baseline experiments, whereas its oscillation amplitude in
long-baseline experiments is of order 1. We also propose a new parameterization
of the four-neutrino mixing matrix U which is appropriate for the schemes under
consideration.


title: Concerning CP violation in 331 models

abstract:
  We consider the implementation of CP violation in the context of 331 models.
In particular we treat a model where only three scalar triplets are needed in
order to give all fermions a mass while keeping neutrino massless. In this case
all CP violation is provided by the scalar sector.


title: Alternative Solution of Strong CP

abstract:
  In this talk I begin with some general discussion of the history of CP
violation, then move on to aspects of a spontaneous CP violation model
including the production of new particles at LHC, implications for B decay,
generalized Cabibbo mixing and a reevaluation of kaon CP violation. Finally
there is a summary.


title: Z_N-symmetry in gauge theories at finite temperatures

abstract:
  The role of Z_N symmetry in gauge theories at finite temperatures is
discussed. This symmetry is studied in terms of A_0-effective potential. We
consider two- and four-dimensional models where the question on physical
interpretation of minima of $A_0$-effective potential can be considered
exactly. It is shown that the correct result for the partition function can be
obtained by summation of contributions near all minima of the $A_0$-effective
potential.


title: First-order nonthermal phase transition after preheating

abstract:
  During preheating after inflation, parametric resonance rapidly generates
very large fluctuations of scalar fields. In models where the inflaton field
$\phi$ oscillates in a double-well potential and interacts with another scalar
field $X$, fluctuations of X can keep the \phi to -\phi symmetry temporarily
restored. If the coupling of \phi to X is much stronger than the inflaton
self-coupling, the subsequent symmetry breaking is a first-order phase
transition. We demonstrate the existence of this nonthermal phase transition
with lattice simulations of the full nonlinear dynamics of the interacting
fields. In particular, we observe nucleation of an expanding bubble.


title: Neutrinos

abstract:
  We can start with the question: why are neutrino properties especially
interesting? Recall that in the minimal standard model there are no right
handed neutrinos and furthermore lepton number is conserved so neutrinos can
have neither Dirac nor Majorana masses. Furthermore, with zero masses, the
mixing angles in the charged weak current are all zero. Any evidence for
non-zero masses or mixing angles is evidence for physics beyond the standard
model and hence potentially a powerful tool. Besides, the masses and mixing
angles are fundamental parameters which will have to be explained by the
eventual theory of fermion masses.


title: Some Phenomenological Aspects of Neutrino Physics

abstract:
  I concentrate on two topics. One is techniques to distinguish amongst various
oscillation scenarios from atmospheric neutrino data; and the other is the
Borexino solar neutrino detector and its capabilities.


title: U(1)' Symmetry Breaking in Supersymmetric E6 Models

abstract:
  We study the electroweak and $U(1)^{'}$ symmetry breaking patterns in models
with the particle content of supersymmetric $E_{6}$, including standard model
singlets $S$ and exotic quarks $D,~\bar{D}$. Motivated by free fermionic string
models, we do not require $E_{6}$-type relations between Yukawa couplings. In
particular, we assume that baryon and lepton numbers are conserved, so that the
exotic quarks can be light. Gauge invariance allows Yukawa interactions between
$S$ and Higgs doublets, and between $S$ and the exotic quarks, allowing
radiative $U(1)^{'}$ symmetry breaking and the generation of an effective $\mu$
parameter at the electroweak scale. For both the $E_{6}$ $\psi$ and $\eta$
models, universal soft supersymmetry breaking parameters and Yukawa
universality at the high (string) scale do not yield acceptable low energy
phenomenology. Relaxing universality, we find solutions with phenomenologically
acceptable values of $M_{Z^{'}}$ and the $Z-Z^{'}$ mixing angle. In addition,
by varying the $U(1)^{'}$ charge assignments due to the mixing of $U(1)_{\chi}$
and $U(1)_{\psi}$ of $E_{6}$, it is possible to have acceptable low energy
phenomenology with universal boundary conditions.


title: Topological Defects Formation after Inflation on Lattice Simulation

abstract:
  We consider the formation of topological defects after inflation. In order to
take into account the effects of the rescattering of fluctuations, we integrate
the classical equation that describes the evolution of a complex scalar field
on the two-dimensional lattice with a slab symmetry. The growth of fluctuations
during preheating is found not to be enough for defect formation, and rather a
long stage of the rescattering of fluctuations after preheating is necessary.
We conclude that the topological defects are not formed if the breaking scale
\eta is lager than \sim (2 - 3)\times 10^{16} GeV.


title:
Hadronic Cross Sections in Electron-Positron Annihilation with Tagged
  Photon

abstract:
  Events with tagged photons in the process of electron-positron annihilation
into hadrons are considered. The initial state radiation is suggested to scan
the hadronic cross section with the energy. QED radiative corrections are taken
into account. The results for the total and exclusive cross sections are given
in an analytic form. Some numerical estimates are presented.


title:
A BFKL Monte Carlo approach to jet production at hadron-hadron and
  lepton-hadron colliders

abstract:
  The production of a pair of jets with large rapidity separation in
hadron-hadron collisions, and of forward jets in deep inelastic scattering, can
in principle be used to test the predictions of the BFKL equation. However in
practice kinematic constraints lead to a strong suppression of BFKL effects for
these processes. This is illustrated using a BFKL Monte Carlo approach.


title: On the odderon intercept in the perturbative QCD

abstract:
  The odderon intercept is calculated directly using the wave function recently
constructed by R.A.Janik and J.Wosiek. The results confirm their reported
value. It is also found that their solution for $q_3=0$ does not satisfy the
Bose-symmetry requirements. Introduction of terms into the trial wave function
with an asymptotical behavior similar to the Janik-Wosiek wave functions does
not seem to improve variational estimates significantly. The diffusion
parameter is found to be of the order 0.6.


title:
A Phenomenological Interpretation of Atmospheric and Solar Neutrino
  Oscillations

abstract:
  We give a phenomenological interpretation of atmospheric and solar neutrino
oscillations by considering two scenarios for the neutrino mass spectrum: (a)
m_1 \ll m_2 \ll m_3 and (b) m_1 \approx m_2 \approx m_3. A new parametrization
of the flavor mixing matrix, which can naturally reflect the hierarchy of
lepton masses in scenario (a) and the approximate decoupling of solar and
atmospheric neutrino oscillations, is highlighted. For scenario (b) an ansatz
starting with flavor democracy for charged leptons and mass degeneracy for
neutrinos is proposed, and two different symmetry breaking possibilities with
``maximal calculability'' are discussed. Finally we point out that possible
(\sin^2 2\theta, \Delta m^2) parameter-space correlation should seriously be
taken into account in future analyses of neutrino oscillations.


title:
A Determination of the Weak Phase \gamma from Color-allowed B^{\pm}_u
  \to DK^{\pm} Decays

abstract:
  We show that it is possible to determine the weak phase \gamma \equiv \arg (-
V^*_{ub} V_{ud} / V^*_{cb} V_{cd}) of the Cabibbo-Kobayashi-Maskawa flavor
mixing matrix only from the measurement of the color-allowed B^{\pm}_u \to D
K^{\pm} decay rates. The uncertainty of this method, arising mainly from the
factorization approximation for two tree-level spectator quark transitions, may
be well controlled.


title:
Reconsidering Composite Higgs Loop Effects in the Top Mode Standard
  Model

abstract:
  Composite Higgs loop effects in the top mode standard model are discussed by
using the Miransky-Tanabashi-Yamawaki (MTY) approach based on the
Schwinger-Dyson equation. The top mass is obtained as 179 GeV for the Planck
scale cutoff (\Lambda \simeq 10^{19} GeV). This result is different from that
of the Bardeen-Hill-Lindner (BHL) approach based on the renormalization group
equation (RGE), with QCD plus Higgs loop effects included (m_t \simeq 205 GeV).
Detailed comparison of the MTY approach with the BHL approach is made. We
derive ``RGE'' from the Pagels-Stokar formula by considering the infrared mass
as the ``renormalization point''. Then, it is found that the MTY approach
including the composite Higgs loop effects is only partially equivalent to the
BHL approach with QCD plus Higgs loop effects. The difference essentially
results from the treatment of the composite Higgs propagator, or more
precisely, of Z_H^{-1}. Our results can be summarized as m_t (Ours) \simeq
1/\sqrt{2} m_t (MTY), in contrast to m_t (BHL) \simeq \sqrt{2/3} m_t (MTY),
where m_t (MTY) \simeq 250 GeV is the original MTY prediction without Higgs
loop effects.


title:
Isovector unpolarized quark distribution in the nucleon in the large-N_c
  limit

abstract:
  We calculate the isovector (flavor-nonsinglet) unpolarized quark- and
antiquark distributions in the nucleon at a low normalization point in the
large-N_c limit. The nucleon is described as a soliton of the effective chiral
theory. The isovector distribution appears in the next-to-leading order of the
1/N_c-expansion. Numerical results for the quark- and antiquark distributions
compare well with the parametrizations of the data at a low normalization
point. This large-N_c approach gives a flavor asymmetry of the antiquark
distribution (violation of the Gottfried sum rule) in good agreement with the
measurements.


title:
The effect of Yukawa couplings on Unification Predictions and the
  non-perturbative limit

abstract:
  We investigate the effects of Yukawa couplings on the phenomenological
predictions for a class of supersymmetric models which allows for the presence
of complete SU(5) multiplets in addition to the Minimal Supersymmetric Standard
Model spectrum. We develop a two loop analytical approach to quantify the
predictions for gauge unification including Yukawa couplings. The effects of
the heavy thresholds of the model are also included. In some cases accurate
predictions can be made for the unification scale, irrespective of the initial
(unknown) Yukawa couplings, so long as perturbation theory remains valid. We
also consider the limit of a large number of extra states and compute the
predictions in a resummed perturbation series approach to show that the results
are stable in this limit. Finally we consider the possibility of making
predictions for the case the gauge and Yukawa couplings enter the
non-perturbative domain below the unification scale and estimate the errors
which affect these predictions.


title:
Maximal Acceleration Corrections to the Lamb Shift of Hydrogen,
  Deuterium and He$^{+}$

abstract:
  The maximal acceleration corrections to the Lamb shift of one--electron atoms
are calculated in a non--relativistic approximation. They are compatible with
experimental results, are in particularly good agreement with the $2S-2P$ Lamb
shift in hydrogen and reduce by $\sim 50%$ the experiment--theory discrepancy
for the $2S-2P$ shift in $He^+$.


title:
Crossover to Non-universal Microscopic Spectral Fluctuations in Lattice
  Gauge Theory

abstract:
  The spectrum of the Dirac operator near zero virtuality obtained in lattice
gauge simulations is known to be universally described by chiral random matrix
theory. We address the question of the maximum energy for which this
universality persists. For this purpose, we analyze large ensembles of complete
spectra of the Euclidean Dirac operator for staggered fermions. We calculate
the disconnected scalar susceptibility and the microscopic number variance for
the chiral symplectic ensemble of random matrices and compare the results with
lattice Dirac spectra for quenched SU(2). The crossover to a non-universal
regime is clearly identified and found to scale with the square of the linear
lattice size and with $f_{\pi}^2$, in agreement with theoretical expectations.


title: Aspects of M Theory and Phenomenology

abstract:
  A brief review is presented of selected topics, including a world-sheet
formulation of M theory, couplings and scales in M phenomenology, the perils of
baryon decay and the possible elevation of free-fermion models to true M- or
F-theory compactifications.


title:
Nonperturbative Contributions to the Hot Electroweak Potential and the
  Crossover

abstract:
  We discuss nonperturbative contributions to the 3-dimensional one-loop
effective potential of the electroweak theory at high temperatures in the
framework of the stochastic vacuum model. It assumes a gauge-field background
with Gaussian correlations which leads to confinement. The instability of
<F^2>=0 in Yang-Mills theory appears for small Higgs expectation value <\phi^2>
in an IR regularized form. The gauge boson propagator obtains a positive
momentum-dependent ``diamagnetic'' effective (mass)^2 due to confinement
effects and a negative one due to ``paramagnetic'' spin-spin interactions which
are related to the <F^2>=0 instability. Numerical evaluation of an approximate
effective potential containing these masses shows qualitatively the fading away
of the first-order phase transition with increasing Higgs mass which was
observed in lattice calculations. The crossover point can be roughly determined
postulating that the effective \phi^4 and \phi^2 terms vanish there.


title: A Low-Nussinov Model for Elastic Vector Meson Production at HERA

abstract:
  I show that a lowest-order pQCD calculation of elastic vector-meson
production does reproduce all the features of experimental measurements at
HERA, for all Q^2 and all mesons, at fixed energy.


title: The BFKL Pomeron in 2+1 Dimensional QCD

abstract:
  We investigate the high-energy scattering in the spontaneously broken Yang -
Mills gauge theory in 2+1 space--time dimensions and present the exact solution
of the leading $\ln s$ BFKL equation. The solution is constructed in terms of
special functions using the earlier results of two of us (L.N.L. and L.S.). The
analytic properties of the $t$-channel partial wave as functions of the angular
momentum and momentum transfer have been studied. We find in the angular
momentum plane: (i) a Regge pole whose trajectory has an intercept larger than
1 and (ii) a fixed cut with the rightmost singularity located at $j=1$. The
massive Yang - Mills theory can be considered as a theoretical model for the
(non-perturbative) Pomeron. We study the main structure and property of the
solution including the Pomeron trajectory at momentum transfer different from
zero. The relation to the results of M. Li and C-I. Tan for the massless case
is discussed.


title:
Photon splitting above the pair creation threshold in a strong magnetic
  field

abstract:
  The process of photon splitting $\gamma \to \gamma \gamma$ in a strong
magnetic field is investigated both below and above the pair creation
threshold. Contrary to the statement by Baier et al., the ``allowed'' channel
$\alw$ is shown not to be a comprehensive description of splitting in the
strong field because the ``forbidden'' channel $\frb$ is also essential. The
partial amplitudes and the splitting probabilities are calculated taking
account of the photon dispersion and large radiative corrections near the
resonance.


title: Resummation of Large Logarithms in the Charm Structure Function

abstract:
  We show how one can resum the large logarithms which occur in the charm
component of the structure function F_{k,c}(x,Q^2,m_c^2) (k=2,L) taken at three
light flavours, in the limit Q^2 \gg m_c^2. This resummation leads to an
expression of the above quantity for four light flavours including the charm
quark density. The latter is related to the parton densities in the three light
flavour number scheme.


title: Flavour Democracy in Strong Unification

abstract:
  We show that the fermion mass spectrum may naturally be understood in terms
of flavour democratic fixed points in supersymmetric theories which have a
large domain of attraction in the presence of "strong unification". Our
approach provides an alternative to the approximate Yukawa texture zeroes of
the Froggatt-Nielsen mechanism. We discuss a particular model based on a broken
gauged $SU(3)_L\times SU(3)_R$ family symmetry which illustrates our approach.


title:
Multiplicity distributions at high energies as a sum of Poissonian-like
  distributions

abstract:
  It is shown that at collider energies experimental multiplicity distributions
are well parameterized by a sum of Gupta-Sarma distributions. This extends
earlier description of the lower energy data by the two parameter sum of
Poissonians. Implications of the proposed parametrization for LHC are
discussed.


title: Patterns of Lorentz symmetry breaking in QED by CPT-odd interaction

abstract:
  A tiny Lorentz symmetry breaking can be mediated in Electrodynamics by means
of the Chern-Simons (CS) interaction polarized along a constant CS vector. Its
presence makes the vacuum optically active that has been recently estimated
from astrophysical data. We examine two possibilities for the CS vector to be
time-like or space-like, under the assumption that it originates from v.e.v. of
some pseudoscalar matter. It is shown that: a) a time-like CS vector makes the
vacuum unstable under pairs creation of tachyonic photon modes with the finite
vacuum decay rate, i.e. it is unlikely realized at macroscopic time scales; b)
on the contrary, the space-like CS vector does not yield any tachyonic modes
and, moreover, if its dynamical counterpart is substantially described by a
scale invariant interaction, then the QED radiation effects induce the
dynamical breaking of Lorentz symmetry, i.e. the occurrence of space-like CS
vector appears to be rather natural.


title: Non-Equilibrium Field Theory Dynamics in Inflationary Cosmology

abstract:
  For simple inflationary models, we provide a consistent and complete scheme
by which the macro-physical details of early universe inflation may be
determined explicitly from the underlying micro-physical theory. We examine
inflationary dynamics within the context of a fully renormalized,
non-perturbative, and non-equilibrium quantum field theory using the closed
time path formalism. We study the non-perturbative dynamics using the
self-consistent Hartree approximation and the large N limit. In addition, we
include gravitation dynamically by means of the semi-classical approximation to
Einstein gravity, allowing the cosmological geometry to be determined
self-consistently by the evolution of the particle fields. We develop a simple
and numerically implementable regularization and renormalization scheme for
which the renormalization counterterms contain no explicit dependence on the
initial state.
  We concern ourselves first with the dynamics of new inflation models, showing
how the dynamics become quantum fluctuation driven. We then describe how these
quantum fluctuations may be reassembled into an effective field which behaves
classically and acts as the source for the gravitational background. This
allows us to determine the spectrum of primordial density perturbations in a
consistent manner. We also examine explosive particle production after
inflation through the processes of spinodal decomposition and parametric
amplification, showing that the non-perturbative backreaction on the inflaton
field prevents catastrophic particle production. We find a strong dependence of
particle production on the expansion rate and on the symmetry properties of the
inflaton.


title: An Improved Model of Direct Gauge Mediation

abstract:
  We present a new, improved model of gauge mediation of dynamical SUSY
Breaking: the model does not have gauge messengers or $\sim 10$ TeV scalars
charged under the Standard Model (SM), thus avoiding the problem of negative
(mass)$^2$ for supersymmetric SM (SSM) scalars faced by some earlier models.
The gauge mediation is direct, i.e., the messengers which communicate SUSY
breaking to the SSM fields carry quantum numbers of the gauge group which
breaks SUSY. These messenger fields couple to a modulus field. The model has a
very simple particle content: the modulus and the messengers are the only
chiral superfields (other than the SSM fields) in the model. The inverted
hierarchy mechanism is used to generate a local SUSY breaking minimum for the
modulus field in a perturbative regime thus making the model calculable.


title:
Trilepton Signal of Minimal Supergravity at the Tevatron Including
  $\tau$-lepton Contributions

abstract:
  The trilepton signal with missing transverse energy ($3\ell+\notE_T$, with
$\ell = e$ or $\mu$) from chargino-neutralino ($\chi^\pm_1 \chi^0_2$)
associated production and decays is studied for the upgraded Fermilab Tevatron
Collider with 2 TeV center of mass energy and integrated luminosity of 2
fb$^{-1}$ (MI) to 20 fb$^{-1}$ (TeV33). In some regions of parameter space in
the minimal supergravity model, $\chi^\pm_1$ and $\chi^0_2$ decay dominantly
into final states with $\tau$ leptons via real or virtual $\tilde{\tau}_1$
sleptons. The contributions from $\tau-$leptonic decays increase the trilepton
signal from $\chi^\pm_1 \chi^0_2$ by at least a factor of two when soft but
realistic cuts on lepton transverse momenta are used. With the Main Injector, a
trilepton signal can be detected at $\tan\beta \equiv v_2/v_1 \sim 3$ for
universal masses $m_{1/2}, m_0 \alt$ 200 GeV.


title: Excited glue and the vibrating flux tube

abstract:
  Recent lattice results for the energy of gluonic excitations as a function of
quark separation are shown to correspond to transverse relativistic flux tube
vibration modes. For large quark separations all states appear to degenerate
into a few categories which are predicted uniquely, given the ground state.


title: Inflationary Reheating in Grand Unified Theories

abstract:
  Grand unified theories may display multiply interacting fields with strong
coupling dynamics. This poses two new problems: (1) What is the nature of
chaotic reheating after inflation, and (2) How is reheating sensitive to the
mass spectrum of these theories ? We answer these questions in two interesting
limiting cases and demonstrate an increased efficiency of reheating which
strongly enhances non-thermal topological defect formation, including monopoles
and domain walls. Nevertheless, the large fluctuations may resolve this
monopole problem via a modified Dvali-Liu-Vachaspati mechanism in which
non-thermal destabilsation of discrete symmetries occurs at reheating.


title: QCD Calculations by Numerical Integration

abstract:
  Calculations of observables in Quantum Chromodynamics are typically performed
using a method that combines numerical integrations over the momenta of final
state particles with analytical integrations over the momenta of virtual
particles. I discuss a method for performing all of the integrations
numerically.


title: Polarized J/psi production at CLEO

abstract:
  Polarizations of the prompt $J/\psi$'s produced in the $e^+e^-$ annihilation
at CLEO energy ($\sqrt{s} = 10.58$ GeV) are considered in the framework of
NRQCD factorization formalism. We find that the $J/\psi$ polarization has
strong dependence on the production mechanism. At CLEO energy, the most
dominant $J/\psi$ production mechanism in the most phase space is the
color-singlet mechanism, $e^+e^- \to J/\psi+gg$, for which $J/\psi$'s are
highly longitudinally polarized. On the other hand, the dominant $J/\psi$
production mechanism at the upper end point of $J/\psi$ energy distribution is
the color-octet process, $e^+e^- \to (c\bar{c})^{(8)} +g$, for which $J/\psi$'s
are almost unpolarized. Thus, the measurement of the polarization of the end
point $J/\psi$'s can give another test of color-octet mechanism, and constraint
on the NRQCD matrix elements.


title:
Exclusive B --> M l^+ l^- (M=\pi, K, \rho, K^*) Decays and
  Determinations of |V_{ts}| (and |V_{td}/V_{ts}|)

abstract:
  We examine the possibility for precise determination of |V_{ts}| (and
|V_{td}/V_{ts}|) from the exclusive decays, $B --> K \ell^+ \ell^-, B --> K^*
\ell^+ \ell^-$ (and $B --> \pi \ell^+ \ell^-, B --> \rho \ell^+ \ell^-$). We
show that the ratio |V_{ts}| can be extracted experimentally with a small
theoretical uncertainty from hadronic form--factors, if we {\bf appropriately
constrain} kinematical regions of $q^2$. We also give detailed analytical and
numerical results on the differential decay width $d\Gamma(B --> K^* \ell^+
\ell^-)/dq^2$, and the ratios of integrated branching fractions, ${\cal B}(B
--> \rho \ell^+ \ell^-)/{\cal B}(B --> K^* \ell^+ \ell^-)$. We estimate that
one can determine the ratio |V_{ts}| from those decays within theoretical
accuracy of $\sim 10%$.


title: Baryon asymmetry and neutron EDM

abstract:
  Baryon asymmetry of the universe can be generated by new sources of $CP$
violation intrinsic in supersymmetric extension of the standard model. This
scenario predicts the neutron electric dipole moment to be not much smaller
than its present experimental upper bound.


title:
B--> K^* l^+ l^- decay in the two Higgs doublet model with flavor
  changing neutral currents

abstract:
  We study the decay width, forward-backward asymmetry and the longitudinal
lepton polarization for the exclusive decay B --> K^* l^+ l^- in the two Higgs
doublet model with three level flavor changing neutral currents (model III) and
analyse the dependencies of these quantities on the the selected parameters,
\xi^{U,D}, of model III including the next to leading QCD corrections. It is
found that to look for charged Higgs effects, the measurements of the branching
ratio, forward-backward asymmetry and the longitudinal lepton polarization for
the decay B --> K^* l^+ l^- are promising.


title: Accurate neutralino relic density

abstract:
  We enlarge our set of supersymmetric models and update accelerator
constraints in our precise calculation of the relic density of the lightest
neutralino, which includes relativistic Boltzmann averaging, subthreshold and
resonant annihilations, and coannihilation processes among charginos and
neutralinos.


title: Two-Loop Gap Equations for the Magnetic Mass

abstract:
  One-loop gap equations have recently been used by several authors to estimate
the non-perturbative mass gap in a 3-dimensional gauge theory. I extend the
method to two loops and demonstrate, that the resulting gap equation has a real
and positive solution $m \simeq 0.34 g^2$, which is in good agreement with the
one-loop results and lattice data.


title:
Baryon Magnetic Moments and Quark Orbital Motion in the Chiral Quark
  Model

abstract:
  Using the unified scheme for describing both quark spin and orbital angular
momenta in the chiral quark model developed in the previous work, the magnetic
moments of octet and decuplet baryons are calculated. The numerical result
shows that the overall agreement with data is improved by including the orbital
contributions.


title: Perturbative Quark Mass Corrections to the Tau Hadronic Width

abstract:
  The perturbative quark-mass corrections to the $\tau$ hadronic width are
analysed to $O(\alpha_s^3 m_q^2)$, using the presently available theoretical
information. The behaviour of the perturbative series is investigated in order
to assess the associated uncertainties. The implications for the determination
of the strange quark mass from $\tau$ decay data are discussed.


title: QCD Phase Shifts and Rising Total Cross-Sections

abstract:
  An attempt is made in QCD to explain the growth of total cross-sections with
energy, without violating the Froissart bound. This is achieved by computing
the phase shifts of elastic scatterings of partons rather than their
amplitudes. To render that possible a general formalism of phase-shifts in QCD
is developed. Computed to two-loop order, agreements with hadronic and
virtual-photon total cross-sections are quite satisfactory. Predications for
the slower rate of growth at higher energies are also presented.


title: Once more on the bound on $\nu_\tau$ magnetic moment from L3 data

abstract:
  We show that recently announced strong bound on $\mu_{\nu_\tau}$ can not be
justified, and confirm original L3 result.


title: Glueball Spectroscopy in Regge Phenomenology

abstract:
  We show that linear Regge trajectories for mesons and glueballs, and the
cubic mass spectrum associated with them, determine a relation between the
masses of the \rho meson and the scalar glueball, M(0^{++})=3/\sqrt{2} M(\rho
), which implies M(0^{++})=1620\pm 10 MeV. We also discuss relations between
the masses of the scalar and tensor and 3^{--} glueballs, M(2^{++})=\sqrt{2}
M(0^{++}), M(3^{--})=2M(0^{++}), which imply M(2^{++})=2290\pm 15 MeV,
M(3^{++})=3240\pm 20 MeV.


title: Anomalous amplitudes in a thermal bath

abstract:
  I review the implications of the axial anomaly in a thermal bath. I assume
that the Adler-Bardeen theorem applies at nonzero temperature, so that the
divergence of the axial current remains is independent of temperature.
Nevertheless, I argue that while the anomaly doesn't change with temperature,
``anomalous'' mesonic couplings do. This is verified by explicit calculations
in a low temperature expansion, and near the chiral phase transition.


title: Mixing of two-level unstable systems

abstract:
  Unstable particles can be consistently described in the framework of quantum
field theory. Starting from the full S-matrix amplitudes of B^+ --> (2 pi, 3
pi) l nu decays as examples in the energy region where the rho-omega resonances
are dominating, we propose a prescription for the mixing of two quasi
`physical' unstable states that differs from the one obtained from the
diagonalization of the M -i*Gamma/2 non-hermitian hamiltonian. We discuss some
important consequences for CP violation in the K_L - K_S system.


title: Decay Rate Asymmetry of the Top Quark through Light Squarks

abstract:
  A decay rate asymmetry of the top quark is discussed within the framework of
the supersymmetric standard model. Although new sources of CP violation in this
model are severely constrained from the electric dipole moments of the neutron
and the electron, there is a possibility that a top squark has a mass of around
100 GeV and CP violation in its interaction with a top quark is unsuppressed.
Then partial widths could be different between the decays $t\to bW^+$ and $\bar
t\to \bar bW^-$. The magnitude of this CP asymmetry can be of order $10^{-3}$,
which may be detectable in the near future.


title:
Improvement of the Calculation of Scattering Amplitudes with External
  Fermions

abstract:
  In this paper, we present an improvement of a method for computing scattering
amplitudes that include external (polarized) fermions with the following
features: the formulas are quite general and work for different kinematic
configurations and different external masses, they are explicitly covariant,
they do not depend on a specific representation of the Dirac matrices and they
have a meaningful limit when the masses tend to 0. The results presented make
use of some well known formulas describing the density matrices in terms of
projection operators within a more general formalism. Since our formulas intend
to be as general as possible, we also take into account the possibility of a
transverse polarization for massless fermions.


title: Late-Time Entropy Production and Relic Abundances of Neutralinos

abstract:
  Many models possess unwanted relics, which should be diluted by entropy
production just before the big-bang nucleosynthesis. A field responsible for
the entropy production may produce stable weakly interacting massive particles,
if kinematically accessible. We compute their relic abundances by integrating
out coupled equations numerically. Applying our results to supersymmetric
standard models, we argue that the neutralino lightest superparticles will
overclose the universe in most of the parameter space if the reheat temperature
is of the order of 10 MeV.


title: Parton Distributions

abstract:
  We present a new analysis of parton distributions of the proton. This
incorporates a wide range of new data, an improved treatment of heavy flavours
and a re-examination of prompt photon production. The new set (MRST) shows
systematic differences from previous sets of partons which can be identified
with particular features of the new data and with improvements in the analysis.
An `explanation' of the behaviour seen on the Caldwell plot is offered.


title: Double Diffraction Dissociation at High t

abstract:
  Diffractive scattering in the presence of a large momentum transfer is an
ideal place to study the short distance rapidity gap producing mechanism.
Previous studies (experimental and theoretical) in this area have focussed on
gaps between jets and on high-$t$ vector meson production. We propose the
measurement of double dissociation at high-$t$. We examine the numerous
advantages to studying this more inclusive process and conclude that it is an
ideal place to study short distance diffraction.


title:
Model-independent limits on four-fermion contact interactions at LC with
  polarization

abstract:
  Fermion compositeness, and other types of new physics that can be described
by the exchange of very massive particles, can manifest themselves as the
result of an effective four-fermion contact interaction. In the case of the
processes $e^+e^-\to \mu^+\mu^-,\tau^+\tau^-,\bar{b}b$ and $\bar{c}c$ at future
$e^+e^-$ colliders with $\sqrt{s}=0.5-1$ TeV, we examine the sensitivity to
four-fermion contact interactions of two new integrated observables, $\sigma_+$
and $\sigma_-$, conveniently defined for such kind of analysis. We find that,
if longitudinal polarization of the electron beam were available, these
observables would offer the opportunity to separate the helicity cross sections
and, in this way, to derive model-independent bounds on the relevant
parameters.


title: Running Coupling Effects in BFKL Evolution

abstract:
  We resum the recently calculated second order kernel of the BFKL equation.
That kernel can be viewed as the sum of a conformally invariant part and a
running coupling part. The conformally invariant part leads to a corrected BFKL
intercept as found earlier. The running coupling part of the kernel leads to a
non-Regge term in the energy dependence of high energy hard scattering, as well
as a $Q^2-$dependent intercept.


title: Cosmic strings from preheating

abstract:
  We investigate nonthermal phase transitions that may occur after
post-inflationary preheating in a simple model of a two-component scalar field
with the effective potential $\lambda (\phi_i^2 - {\rm v}^2)^2/4$, where
$\phi_1$ is identified with the inflaton field. We use three-dimensional
lattice simulations to investigate the full nonlinear dynamics of the model.
Fluctuations of the fields generated during and after preheating temporarily
make the effective potential convex in the $\phi_1$ direction. The subsequent
nonthermal phase transition with symmetry breaking leads to formation of cosmic
strings even for ${\rm v} \gg 10^{16}$ GeV. This mechanism of string formation,
in a modulated (by the oscillating field $\phi_{1}$) phase transition, is
different from the usual Kibble mechanism.


title: Bose-Einstein Interference and Factorization at High Energies

abstract:
  We consider the emission or absorption of $n$ identical bosons from an
energetic or a massive particle, in which the bosons and the source particle
are allowed to be offshell. The Bose-Einstein symmetrized amplitude can be
decomposed into sums and products of more elementary objects which we choose to
call `atoms'. The origin of this decomposition, its significance and some of
its applications will be summarized.


title: Domain Wall Production During Inflationary Reheating

abstract:
  We numerically investigate the decay, via parametric resonance, of the
inflaton with an m^2 phi^2 potential into a scalar matter field with a symmetry
breaking potential. We consider the case where symmetry breaking takes place
during inflation. We show that when expansion is not taken into account
symmetry restoration and non-thermal defect production during reheating is
possible. However in an expanding universe the fields do not spend sufficient
time in the instability bands; thus symmetry restoration and subsequent domain
wall production do not occur.


title:
Extracting information on CKM phases, electro-weak penguins and new
  physics from B --> VV decays

abstract:
  We derive constraints for $B\to VV$ modes ($V= vector meson) that allow
aquantitative assessment of the contributions from electroweak penguins (EWP)
and/or new physics. Interplay of direct CP with oscillation studies then leads
to the extraction of the angles alpha and gamma, using B--> K* omega rho and
B--> rho omega (phi) respectively, if by using our constraint equations it can
be experimentally demonstrated that color-suppressed EWP are small.


title:
Scaling Behavior of Multiplicity Distribution under First-Order
  Quark-Hadron Phase Transition

abstract:
  Multiplicity distribution in small bins is studied within the Ginzburg-Landau
description for first-order quark-hadron phase transition. Direct comparison of
the distribution with a Poisson one (with the same average) is made. Dynamical
factor $d_q$ for the distributionand ratio $D_q\equiv d_q/d_1$ are studied, and
novel scaling behaviors between $D_q$ are found which can be used to detect the
formation of quark-gluon plasma.


title: QCD at \theta \sim \pi

abstract:
  Taking into account the quadratic in mass terms in the effective chiral
lagrangian, we show that, at \theta \sim \pi, the theory with 2 light quarks of
equal mass involves two degenerate vacuum states separated by a barrier. For
three flavors, the energy barrier between two vacua appears already in the
leading order in mass. This corresponds to the first order phase transition at
\theta = \pi. The surface energy density of the domain wall separating two
different vacua is calculated. In the immediate vicinity of the phase
transition point, two minima of the potential still exist, but one of them
becomes metastable. The probability of the false vacuum decay is estimated.


title: The Perturbative Pole Mass in QCD

abstract:
  It is widely believed that the pole mass of a quark is infrared-finite and
gauge-independent to all orders in perturbation theory. This seems not to have
been proved in the literature. A proof is provided here.


title:
Massive Fermionic Corrections to the Heavy Quark Potential Through Two
  Loops

abstract:
  A physically defined effective charge can incorporate quark masses
analytically at the flavor thresholds. Therefore, no matching conditions are
required for the evolution of the strong coupling constant through these
thresholds. In this paper, we calculate the massive fermionic corrections to
the heavy quark potential through two loops. The calculation uses a mixed
approach of analytical, computer-algebraic and numerical tools including Monte
Carlo integration of finite terms. Strong consistency checks are performed by
ensuring the proper cancellation of all non-local divergences by the
appropriate counterterms and by comparing with the massless limit. The size of
the effect for the (gauge invariant) fermionic part of $\alpha_V (q^2,m^2) $
relative to the massless case at the charm and bottom flavor thresholds is
found to be of order 33%.


title:
Experimental Status of Gravitational-Strength Forces in the
  Sub-Centimeter Regime

abstract:
  We review the experimental constraints on additional macroscopic Yukawa
forces for interaction ranges below 1 cm., and summarize several theoretical
predictions of new forces in this region. An experiment using 1 kHz mechanical
oscillators as test masses should be sensitive to much of the parameter space
covered by the predictions.


title: QCD Sum Rules and Hadronic Radial Excitations of Light Mesons

abstract:
  We reminde definite results related to the low-energy hadronic phenomenology,
obtained using the QCD sum rules methods. We emphasize that these results can
be of interest for the comparison with available and new experimental results,
obtained in part by the experimentalists of IHEP (Protvino).


title: Pathways to Naturally Small Neutrino Masses

abstract:
  In the minimal standard electroweak gauge model, there is an effective
dimension-five operator which generates neutrino masses, and it has only three
tree-level realizations. One is the canonical seesaw mechanism with a
right-handed neutrino. Another is having a heavy Higgs triplet as recently
proposed. The third is to have a heavy Majorana fermion triplet, an example of
which is presented here in the context of supersymmetric SU(5) grand
unification. The three generic one-loop realizations of this operator are also
discussed.


title: Hadron Mass Scaling in Regge Phenomenology

abstract:
  We show that Regge phenomenology is consistent with the only universal
scaling law for hadron masses, M^\ast /M=(\alpha ^{'}/\alpha ^{'\ast})^{1/2},
where asterisk indicates a finite-temperature quantity. Phenomenological models
further suggest the following expression of the above scaling in terms of the
temperature-dependent gluon condensate: M^\ast / M =
(\alpha^'/\alpha^{'\ast})^{1/2} = (<G_{\mu\nu}^a>^\ast/<G^{a\mu\nu}>)^{1/4}.


title:
Observation of Ultrahigh Energy Neutrino Interactions by Orbiting
  Detectors

abstract:
  Orbiting detectors will be able to observe showers initiated by neutrinos
penetrating the Earth and interacting close to their exit point. There is a
correlation between the impact parameter of the incident neutrino and its
energy. We study the development of upward going, neutrino induced showers in
the atmosphere.


title:
Nonspectator Effects and B Meson Lifetimes from a Field-theoretic
  Calculation

abstract:
  The B meson lifetime ratios are calculated to the order of $1/m_b^3$ in the
heavy quark expansion. The predictions of those ratios are dependent on four
unknown hadronic parameters $B_1$, $B_2$, $\epsilon_1$ and $\epsilon_2$, where
$B_1$ and $B_2$ parametrize the matrix elements of color singlet-singlet
four-quark operators and $\epsilon_1$ and $\epsilon_2$ the matrix elements of
color octet-octet operators. We derive the renormalization-group improved QCD
sum rules for these parameters within the framework of heavy quark effective
theory. The results are $B_1(m_b)=0.96\pm 0.04$, $B_2(m_b)=0.95\pm 0.02$,
$\epsilon_1(m_b)=-0.14\pm 0.01$, and $\epsilon_2(m_b)=-0.08\pm 0.01$ to zeroth
order in $1/m_b$. The resultant $B$ meson lifetime ratios are
$\tau(B^-)/\tau(B_d)=1.11\pm 0.02$ and $\tau(B_s)/\tau(B_d)\approx 1$ in SU(3)
symmetry limit.


title: WW decays and Bose-Einstein correlations

abstract:
  Various methods of implementing the Bose-Einstein effect into Monte Carlo
generators, especially for the process e^+ e^- > W^+ W^-, are briefly reviewed
and their predictions for the W mass shifts are compared. The weight methods,
which yield very similar predictions independent on the detailed prescription
for weights, are discussed in more detail. In particular, we advocate a new
method, which seems to be practical and reasonably well justified
theoretically.


title:
A new technique for computing the spectral density of sunset-type
  diagrams: integral transformation in configuration space

abstract:
  We present a new method to investigate a class of diagrams which generalizes
the sunset topology to any number of massive internal lines. Our attention is
focused on the computation of the spectral density of these diagrams which is
related to many-body phase space in $D$ dimensional space-time. The spectral
density is determined by the inverse $K$-transform of the product of
propagators in configuration space. The inverse $K$-transform reduces to the
inverse Laplace transform in any odd number of space-time dimensions for which
we present an explicit analytical result.


title: Integrability of three-particle evolution equations in QCD

abstract:
  We show that Brodsky-Lepage evolution equation for the leading twist spin 3/2
baryon distribution amplitude is completely integrable and reduces to the
three-particle XXX_{s=-1} Heisenberg spin chain. Trajectories of the anomalous
dimensions are identified and calculated using the 1/N expansion. Extending
this result, we prove integrability of the evolution equations for twist 3
quark-gluon operators in the large N_c limit and derive explicit expressions
for the corresponding integrals of motion.


title:
Diffractive dijet photoproduction and the off-diagonal gluon
  distribution

abstract:
  Diffractive dijet photoproduction is proposed as a probe of the off-diagonal
gluon distribution and its evolution. Predictions for the transverse momentum
distribution of the jets are given. Differences with DGLAP evolution are
highlighted.


title: Forming a Single, Large, DCC Domain in a Heavy-Ion Collision

abstract:
  We demonstrate the possibility of forming a single, large domain of
disoriented chiral condensate (DCC) in a heavy-ion collision. In our scenario,
rapid initial heating of the parton system provides a driving force for the
chiral field, moving it away from the true vacuum and forcing it to go to the
opposite point on the vacuum manifold. This converts the entire hot region into
a single DCC domain. Subsequent rolling down of the chiral field to its true
vacuum will then lead to emission of a large number of (approximately) coherent
pions. The requirement of suppression of thermal fluctuations to maintain the
(approximate) coherence of such a large DCC domain, favors three dimensional
expansion of the plasma over the longitudinal expansion even at very early
stages of evolution. This also constrains the maximum temperature of the system
to lie within a window. We roughly estimate this window to be about 200 - 400
MeV. These results lead us to predict that extremely high energy collisions of
{\it very small nuclei} (possibly hadrons) are better suited for observing
signatures of a large DCC. Another possibility is to focus on {\it peripheral}
collisions of heavy nuclei.


title: Energy and Virtuality Scale Dependence in Quark and Gluon Jets

abstract:
  We discuss some important issues concerning multiplicities in quark and gluon
jets in e+e- annihilation. In QCD the properties of a jet in general depend on
two scales, the energy and virtuality of the jet. Frequently theoretical
predictions apply to a situation where these scales coincide, while for
experimental data they are often different. Thus an analysis to extract e.g.
the asymptotic multiplicity ratio CF/CA between quark and gluon jets, needs a
carefully specified jet definition, together with a calculation of nonleading
corrections to the multiplicity evolution.
  We propose methods to systematically study the separate dependence upon the
two scales in experimental data and compare the results with theory. We present
jet finding algorithms which corresponds well to the theoretically considered
jets. We also show that recoil effects add corrections to the modified leading
log approximation which are quantitatively important, though formally
suppressed at high energies.


title:
Strongly Interacting Vector Bosons at the LHC: Quartic Anomalous
  Couplings

abstract:
  We analyze the potential of the CERN Large Hadron Collider to study anomalous
quartic vector--boson interactions through the production of vector--boson
pairs accompanied by jets. In the framework of $SU(2)_L \otimes U(1)_Y$ chiral
Lagrangians, we examine all effective operators of order $p^4$ that lead to new
four--gauge--boson interactions but do not alter trilinear vertices. In our
analyses, we perform the full tree level calculation of the processes leading
to two jets plus vector--boson pairs, $W^+W^-$, $W^\pm W^\pm$, $W^\pm Z$, or
$ZZ$, taking properly into account the interference between the standard model
and the anomalous contributions. We obtain the bounds that can be placed on the
anomalous quartic interactions and we study the strategies to distinguish the
possible new couplings.


title: IR renormalon effects and light mesons' elm form factor

abstract:
  The pion and kaon electromagnetic form factors $F_M(Q^2)$ are calculated at
the leading order of pQCD using the running coupling constant method. In
calculations a dependence of the mesons distribution amplitudes on the hard
scale $Q^2$ is taken into account. The Borel transform and resummed expression
for $F_M(Q^2)$ are found.


title: Multi-photon effects in energy losses spectra

abstract:
  Effect of radiation of many photons by a single electron traversing a target
is discussed. When the summary energy of emitted photons (the energy losses
spectrum) is measured only, the photon spectrum is distorted comparing with the
photon spectrum in one interaction. Influence of this effect is discussed for
the cases (1) bremsstrahlung (described by Bethe-Heitler formula), (2) the
strong Landau-Pomeranchuk-Migdal effect and (3) transition radiation.
Qualitative picture of the phenomenon is discussed in detail. Comparison with
the recent SLAC experiment in relatively thick target (2.7% of the radiation
length), where the effect of emission of many photons by a projectile is very
essential, shows perfect agreement of the theory and data.


title: Mass Corrections to the Tau Decay Rate

abstract:
  In this note radiative corrections to the total hadronic decay rate of the
$\tau$-lepton are studied employing perturbative QCD and the operator product
expansion. We calculate quadratic quark mass corrections to the decay rate
ration $R_{\tau}$ to the order ${\cal O}(\alpha_s^2 m^2)$ and find that they
contribute appreciably to the Cabbibo supressed decay modes of the
$\tau$-lepton. We also discuss corrections of mass dimension D=4, where we
emphasize the need of a suitable choice of the renormalization scale of the
quark and gluon condensates.


title:
Heavy Quark Initiated Contributions to Deep Inelastic Structure
  Functions

abstract:
  We present O(alpha_s^1) corrections to deep inelastic scattering amplitudes
on massive quarks obtained within the scheme of Aivazis, Collins, Olness and
Tung (ACOT). After identifying the correct subtraction term the convergence of
these contributions towards the analogous coefficient functions for massless
quarks, obtained within the modified minimal subtraction scheme (MSbar), is
demonstrated. Furthermore, the quantitative relevance of the contributions to
neutral current (NC) and charged current (CC) structure functions is
investigated for several choices of the factorization scale.


title:
Off-diagonal helicity density matrix elements for heavy vector mesons
  inclusively produced in N-N, gamma-N, l-N interactions

abstract:
  Final state interactions in quark fragmentation may give origin to non zero
values of the off-diagonal element rho_(1,-1) of the helicity density matrix of
vector mesons V produced in current jets, with a large energy fraction x_E; the
value of rho_(1,-1)(V) is related to the hard constituent dynamics and tests
unusual properties of it. Some recent data on phi, K^* and D^* produced in e^+
e^- annihilations at LEP show such effects. Predictions are given here for
rho_(1,-1) of heavy mesons produced in nucleon-nucleon, gamma-nucleon and
lepton-nucleon interactions.


title: Final state interaction in decays B----->Kaon Pion

abstract:
  We discuss the rescattering effects in decays $B\to \pi+K$. The picture we
take is very simple: first, B decay into $K*\rho$, then $K*$ and $\rho$ go to
kaon and pion by exchanging a pion. We find a up to ten percent CP violation
asymmetry rate. We also discuss its correction to the constraint of angle
$\gamma$ proposed recently.


title: GCP Code Applied in $J/\psi$ Production and Absorption

abstract:
  Using the General Cascade Program(GCP), the production and absorption of
$J/\psi$ in p-A and A-A collisions have been studied. Nucleon absorption
mechanism and comover absorption mechanism are considered to investigate the
$J/\psi$ suppression. The results agree well with experimental data of $J/\psi$
production, except for the data in Pb-Pb collision.


title: Dynamical supersymmetry breaking in a superstring inspired model

abstract:
  We present a dilaton dominated scenario for supersymmetry breaking in a
recently constructed realistic superstring inspired model with an anomalous
U(1) symmetry. Supersymmetry is broken via gaugino condensation due to a
confining SU(Nc) gauge group in the hidden sector. In particular, we find that
by imposing on the model the phenomenological constraint of the absence of
observed flavor changing neutral currents, there is a range of parameters
related to the hidden sector and the Kahler potential for which we obtain a low
energy spectrum consistent with present experimental bounds. As an illustrative
example, we derive the low energy spectrum of a specific model. We find that
the LSP is the lightest neutralino with a mass of 53 GeV and the lightest Higgs
has a mass of 104 GeV.


title: Boron abundance and solar neutrino spectrum distortion

abstract:
  The presence of neutrinos from Boron decay in the flux observed on Earth is
attested by the observation of their energy spectrum. Possible distortions of
the spectrum investigated in current detectors are often interpreted in terms
of evidence in favour or against various schemes of neutrino oscillations. We
stress here that a distortion of the spectrum at high energies could also
result from an increase in the ratio of neutrinos originating from ($^3$He+p)
and $^8$B reactions. While a $^8$B neutrino depletion would contribute to this
effect, an increase in the Hep contribution seems also needed to reproduce the
preliminary data.


title: Exclusive radiative weak decays of B_c meson in light cone QCD

abstract:
  We investigate the radiative B_c -> rho^+ gamma and B_c -> K^{*+} gamma
decays in the standard model. The transition form factors are calculated in the
framework of the light cone QCD sum rules method. We estimate the branching
ratios of the B_c -> rho^+ gamma and B_c -> K^{*+} gamma decays.


title: Supergravity Resolution of the Unification to Planck Scale Hierarchy

abstract:
  It is demonstrated how the hierarchy between the gauge coupling unification
scale of minimal supersymmetry and the Planck (or string) scale, which
resembles in order of magnitude a loop factor, can actually be explained as
such in supergravity-coupled supersymmetry. A gauge and global singlet field
acquires a linear potential term due to its one-loop supergravity interactions
and slides to the desired scale. The singlet field can then provide the seed
for the breaking of the unified theory at the appropriate scale via its
couplings to fields in the adjoint representation.


title: Heavy flavor decays, OPE and duality in two-Dimensional 't Hooft model

abstract:
  The 't Hooft model (two-dimensional QCD in the limit of large number of
colors) is used as a laboratory for exploring various aspects of the heavy
quark expansions in the nonleptonic and semileptonic decays of heavy flavors.
We perform a complete operator analysis and construct the operator product
expansion (OPE) up to terms O(1/m_Q^4), inclusively. The OPE-based predictions
for the inclusive widths are then confronted with the "phenomenological"
results, obtained by summation of all open exclusive decay channels, one by
one. The summation is carried out analytically, by virtue of the 't Hooft
equation. The two alternative expressions for the total widths match. We
comment on the recent claim in the literature of a 1/m_Q correction to the
total width which would be in clear conflict with the OPE result. The issue of
duality violations both in the simplified setting of the 't Hooft model and in
actual QCD is discussed. The amplitude of oscillating terms is estimated.


title: Light Charged Higgs Bosons in Supersymmetric Models

abstract:
  We point out that present experimental limits from searches for neutral Higgs
bosons at LEP already imply stringent lower bounds on the mass of the charged
Higgs boson in the Minimal Supersymmetric Standard Model (MSSM); these bounds
are especially severe for low values of \tanb ($\tanb \leq 3$), where the $H^+
\bar{t} b$ coupling is large. However, these indirect constraints are much
weaker in simple extensions of the MSSM Higgs sector involving the introduction
of an extra U(1) gauge group or an extra $SU(2) \times U(1)_Y$ Higgs singlet
field; in the latter case charged Higgs bosons can even be light enough to be
pair produced at LEP.


title:
Dynamical Chiral Symmetry Breaking in Effective Models of QCD in the
  Bethe-Salpeter Approach

abstract:
  Dynamical breaking of chiral symmetry in effective models of QCD is studied.
Introducing a cut-off function or a non-local interaction, the Noether current
must be modified and thus the Ward-Takahashi identity and the PCAC relation are
modified accordingly. We point out that the pion decay constant must be defined
consistently with the Noether current so that the low-energy relations are
satisfied. We define the proxy of the Noether current for general effective
models, which is consistent with loop expansion of the
Cornwall-Jackiw-Tomboulis effective action. A general formula for the pion
decay constant in terms of the Bethe-Salpeter amplitude is derived.
  The effective Pagels-Stokar formula is proposed which is useful to estimate
the decay constant without solving the Bethe-Salpeter equation.


title: Neutral Higgs-Boson Pair Production at Hadron Colliders: QCD Corrections

abstract:
  Neutral Higgs-boson pair production provides the possibility of studying the
trilinear Higgs couplings at future high-energy colliders. We present the QCD
corrections to the gluon-initiated processes in the limit of a heavy top quark
in the loops and the Drell-Yan-like pair production of scalar and pseudoscalar
Higgs particles. The pp cross sections are discussed for LHC energies within
the Standard Model and its minimal supersymmetric extension. The QCD
corrections are large, enhancing the total cross sections significantly.


title: Spectrum of the Odderon Charge for Arbitrary Conformal Weights

abstract:
  The odderon equation is studied in terms of the variable suggested by the
modular invariance of the 3 Reggeon system. Odderon charge is identified with
the cross-product of three conformal spins. A complete set of commuting
operators: h^2 and q is diagonalized and quantization conditions for
eigenvalues of the odderon charge q are solved for arbitrary conformal weight
h.


title: Probing the sgeneration spectrum in chargino decays

abstract:
  Some mechanisms of supersymmetry breaking result in splitting of the third
generation sfermions from the other sfermions. We show that the three-body
decay branching ratio of the lighter chargino gives a sensitive probe of the
sfermion mass spectrum if the chargino has a large gaugino component.


title: String Clustering and J/Psi Suppression in Nuclear Collisions

abstract:
  We study the clustering of colour strings in the transverse plane of
nucleus-nucleus collisions and argue that deconfinement sets in when the string
density within a cluster reaches a critical value. We show that this implies a
minimal cluster size at the onset of deconfinement, which in turn results in
discontinuous behaviour for J/Psi suppression.


title: Sfermion Pair Production at $\mu^+ \mu^-$ Colliders

abstract:
  We discuss pair production of stops, sbottoms, staus and tau--sneutrinos at a
$\mu^+ \mu^-$ collider. We present the formulae for the production cross
sections and perform a detailed numerical analysis within the Minimal
Supersymmetric Standard Model. In particular, we consider sfermion production
near $\sqrt{s} = m_{H^0}$ and $\sqrt{s} = m_{A^0}$.


title:
Measurement of Atmospheric Neutrino Oscillations with a High-Density
  Detector

abstract:
  We propose an experiment to test the hypothesis that the reported anomaly on
atmospheric neutrino fluxes is due to nu_mu <-> nu_x oscillations. It will rely
both on a disappearance technique, exploiting the method of the dependence of
the event rate on L/E, which was recently shown to be effective for detection
of neutrino oscillation and measurement of the oscillation parameters, and on
an appearance technique, looking for an excess of muon-less events at high
energy produced by upward-going tau neutrinos. The detector will consist of
iron planes interleaved by limited streamer tubes. The total mass will be about
30 kt. The possibility of recuperating most of the instrumentation from
existing detectors allows to avoid R&D phases and to reduce construction time.
In four years of data taking, this experiment will be sensitive to oscillations
nu_mu <-> nu_x with Delta m^2 > 10^-4 eV^2 and a mixing near to maximal, and
answer the question whether nu_x is a sterile or a tau neutrino.


title: Rising Bosonic Electroweak Virtual Effects at High Energy e+e- Colliders

abstract:
  The virtual massive gauge boson effects on several observables in the process
of charged fermion pairs production at $e^+e^-$ colliders are computed up to
the TeV energy range in the Standard Model, working in the ``$Z$-peak
subtracted'' representation. It is shown that these effects increase regularly
with energy, approaching the typical ten percent relative size. A careful
numerical evaluation is proposed, where the conditions dictated by gauge
invariance are consistently implemented.


title:
Strangeness Contribution to the Polarized Nucleon Structure Function
  $g_1(x)$

abstract:
  The three flavor version of the Nambu-Jona-Lasinio chiral soliton model for
baryons is employed to calculate the twist-2 contribution to the polarized
nucleon structure function $g_1(x)$. In particular the role of the strange
quark degree of freedom as a collective excitation of the chiral soliton is
investigated in the context of flavor symmetry breaking. The model prediction
for $g_1(x)$ refers to a low momentum scale $Q_0^2$. The leading order
corrections to the scale dependence is computed along the QCD evolution program
allowing to compare with data from SLAC.


title: Electroweak Baryogenesis: A Brief Review

abstract:
  A brief review of the fundamental ideas behind electroweak baryogenesis is
presented. Since a successful implementation of these ideas requires an
extension of the minimal standard model, I comment on the necessary physics and
how experimental constraints make these scenarios testable at the LHC, and
perhaps at existing colliders.


title:
Constraints on Electroweak Contact Interactions from LEP and Tevatron
  Data

abstract:
  A complete set of dimension-6 effective contact interactions involving Higgs,
gauge bosons and quarks is studied. Limits on the coefficients of these new
operators are obtained from the experimental values of the $Z$ and $W$ gauge
bosons widths.


title: A New Model of Topcolor-Assisted Technicolor

abstract:
  I present a model of topcolor-assisted technicolor that can have topcolor
breaking of the desired pattern, hard masses for all quarks and leptons, mixing
among the heavy and light generations, and explicit breaking of all
technifermion chiral symmetries except electroweak $SU(2) \otimes $U(1). These
positive features depend on the outcome of vacuum alignment. The main flaw in
this model is tau-lepton condensation.


title:
Definition of the Electromagnetic Field in the Broken-Symmetry Phase of
  the Electroweak Theory

abstract:
  In the broken-symmetry phase of the electroweak theory there is no unique
definition of the electromagnetic field tensor in cases where the magnitude of
the Higgs field differs from a constant value. The meaning of the
electromagnetic field is therefore dubious near defects and during
non-equilibrium stages of the electroweak phase transition. Nevertheless, by
imposing a minimal set of natural requirements one is led to a specific,
gauge-invariant definition that retains the familiar properties of an
electromagnetic field. An electromagnetic vector potential is constructed whose
curl (exterior derivative) in any gauge gives the electromagnetic field tensor.
As is required, this vector potential transforms at most by a pure gradient
under arbitrary SU(2)xU(1) gauge transformations. The flux of the magnetic
field is expressed as a gauge-invariant line integral. Curiously, this provides
a definition for magnetic flux in cases where the spatial region with broken
symmetry is not simply connected and the magnetic field itself is not
everywhere defined.


title:
Analyses of multiplicity distributions by means of the Modified Negative
  Binomial Distribution and its KNO scaling function

abstract:
  We analyze various data of multiplicity distributions by means of the
Modified Negative Binomial Distribution (MNBD) and its KNO scaling function,
since this MNBD explains the oscillating behavior of the cumulant moment
observed in e^+e^- annihilations, h-h collisions and e-p collisions. In the
present analyses, we find that the MNBD(discrete distributions) describes the
data of charged particles in e^+e^- annihilations much better than the Negative
Binomial Distribution (NBD). To investigate stochastic property of the MNBD, we
derive the KNO scaling function from the discrete distribution by using a
straightforward method and the Poisson transform. It is a new KNO function
expressed by the Laguerre polynomials. In analyses of the data by using the KNO
scaling function, we find that the MNBD describes the data better than the
gamma function.Thus, it can be said that the MNBD is one of useful formulas as
well as NBD.


title:
Analyses of multiplicity distributions of e^+e^- and e-p collisions by
  means of modified negative binomial distribution and Laguerre-type
  distribution: Interrelation of solutions in stochastic processes

abstract:
  A pure birth stochastic process with several initial conditions is
considered.We analyze multiplicity distributions of e^+e^- collisions and e-p
collisions, usigthe Modified Negative Binomial Distribution (MNBD) and the
Laguerre-type distribution. Several multiplicity distributions show the same
minimum \chi^2's values in analyses by means of two formulas: In these cases,
we find that a parameter N contained in the MNBD becomes to be large. Taking
large N limit in the MNBD, we find that the Laguerre-type distribution can be
derived from it. Moreover, from the generalized MNBD we can also derive the
generalized Glauber-Lachs formula. Finally stochastic properties of QCD and
multiparticle dynamics are discussed.