title:
Effect of the Haar measure on the finite temperature effective potential
  of $SU(2)$ Yang-Mills theory

abstract:
  Including the Haar measure we show that the effective potential of the
regularized SU(2) Yang-Mills theory has a minimum at vanishing Wilson-line
$W=0$ for strong coupling, whereas it develops two degenerate minima close to
$W=\pm 1$ for weak coupling. This suggests that the non-abelian character of
$SU(2)$ as contained in the Haar measure might be responsible for confinement.


title: Glueball Masses in QCD_3

abstract:
  We discuss how to extract the spectroscopy of quantum chromodynamics (QCD) in
the pure gauge sector from the Hamiltonian lattice field theory approach. The
recently developed truncated eigenvalue equation method is applied to the
estimation of the scalar glueball $0^{++}$ and $0^{--}$ masses in the
(2+1)-dimensional case. These masses reach the constant values in a scaling
region as required by the renormalizability.


title:
Qualitative Consideration Of The Effect Of Binding In Deep Inelastic
  Scattering

abstract:
  In our recent paper (hep-ph/9501348) we argued that the Bjorken variable $x$
in deep inelastic scattering cannot be interpreted as the light cone momentum
fraction $\xi$ even in the Bjorken limit and in zero order of the perturbation
theory. The purpose of the present paper is to qualitatively explain this fact
using only a few simplest kinematical relations.


title: Novel Scalar Boson Decays in SUSY with Broken R-Parity

abstract:
  R parity violation can induce mixing of the supersymmetric Higgs bosons with
the sneutrinos at the tree level. We study the effect of this mixing on the
decays of Higgs scalars as well as sneutrinos in an effective model where the
violation of R parity is included in the minimal supersymmetric model through
bilinear lepton number violating superpotential terms. We show that a small
violation of R parity can lead to a sizeable branching ratio for the
supersymmetric Higgs boson decay mode $H \to \chi \ell$ (where $\chi$ denotes
an electroweak gaugino and $\ell$ is either a tau neutrino or a tau lepton).
Relevant constraints on R parity violation as well as those coming from SUSY
particle searches still allow the decay $H \to \chi \ell$ to compete with the
conventional decay $H\ra b \bar{b}$, at least for some ranges of parameters of
the model. Moreover, the tau sneutrino will have dominant R parity violating
decays to standard model fermions $b \bar{b}$, $\tau^+ \tau^-$ or to the
invisible mode $\nu \bar{\nu}$ whenever the phase space for R parity conserving
channels is closed.


title:
Interference Between Cabibbo Allowed and Doubly Forbidden Transitions in
  $D\ra K_{S,L} + \pi '$s Decays

abstract:
  Both Cabibbo allowed and doubly forbidden transitions contribute coherently
to $D\rightarrow K_{S,L}+\pi 's$ decays. This leads to several intriguing and
even quantitatively significant consequences, among them: (i) A difference
between $\Gamma (D^+\rightarrow K_S \pi ^+)$ and $\Gamma (D^+\rightarrow K_L
\pi ^+)$ and between $\Gamma (D^0\rightarrow K_S \pi ^0)$ and $\Gamma
(D^0\rightarrow K_L \pi ^0)$ of roughly 10\% ; similarly $\Gamma
(D^+\rightarrow [K_S\pi ^0]_{K^*} \pi ^+) \neq \frac{1}{4}\Gamma
(D^+\rightarrow [K^-\pi ^+]_{K^*} \pi ^+)$, and more generally $\Gamma
(D\rightarrow \bar K^0+\pi 's) \neq 2\Gamma (D\rightarrow K_S+\pi 's)$. (ii) A
change in the relative phase between the isospin 3/2 and 1/2 amplitudes as
extracted from the observed branching ratios for $D^+\rightarrow K_S\pi ^+$,
$D^0\rightarrow K_S\pi ^0 ,\, K^-\pi ^+$. (iii) If New Physics intervenes to
provide the required {\em weak} phase, then CP asymmetries of up to a few per
cent can arise in $D^+\rightarrow K_S\pi ^+$ vs. $D^-\rightarrow K_S\pi ^-$,
$D^0\rightarrow K_S\pi ^0$ vs. $\bar D^0\rightarrow K_S\pi ^0$, $D^+\rightarrow
[K_S\pi ^0]_{K^*}\pi ^+$ vs. $D^-\rightarrow [K_S\pi ^0]_{K^*}\pi ^-$, etc.; an
asymmetry of the same size, but opposite in sign occurs when the $K_S$ is
replaced by a $K_L$ in the final state.


title:
Effects of supersymmetric grand unification scale physics on $\Gamma
  \left( b\to s\gamma\right)$

abstract:
  Although calculations of the $b\rightarrow s\gamma$ rate in supersymmetric
grand unified models have always either ignored the gluino mediated
contribution or found it to be negligible, we show that taking universal
supersymmetry breaking masses at the Planck scale, rather than at the gauge
unification scale as is customary, leads to the gluino contribution being more
significant and in fact sometimes even larger than the chargino mediated
contributions when $\mu >0$ and $\tan{\beta}$ is of order 1. The impact is
greatest felt when the gluinos are relatively light. Taking the universal
boundary condition at the Planck scale also has an effect on the chargino
contribution by increasing the effect of the wino and higgsino-wino mediated
decays. The neutralino mediated contribution is found to be enhanced, but
nevertheless it remains relatively insignificant.


title: SUSY and CP Violation

abstract:
  Flavor changing neutral current and CP violating processes are discussed in
the minimal supergravity model. The constraint on charged Higgs mass from the
new measurement of the inclusive branching ratio of the $b\rightarrow s\gamma$
process is obtained. The $B^0_d-\bar{B}^0_d$ mixing parameter ($x_d$) and the
CP violating parameter in the $K^0-\bar{K}^0$ mixing ($\epsilon _K$) are
calculated in this model and it is shown that these parameters can be enhanced
by 10\% $\sim$ 20 \% compared to the prediction within the standard model.
Impacts on new physics search at B factories are also discussed.


title: An Introduction to the Heavy Quark Effective Theory

abstract:
  These lecture notes begin with a brief survey of the physics of heavy quark
systems. This discusion motivates the introduction of the Heavy Quark Effective
theory (HQET) which captures a great deal of the intuition developed. A
derivation of the HQET from QCD is presented as well as an analysis of its
special properties. The effective theory can be seen to amount to a
one-dimensional field theory in the quark sector. The heavy quark flavour- and
spin- symmetry of the effective lagrangian is an offspring of this. Other
topics covered include the question of covariance of the theory, the
construction of interpolating fields for the heavy hadron states, the
application of LSZ reduction theorems to determine the (reduced) number of form
factors in flavour changing transitions, a complete verification of Luke's
theorem, plus the matching conditions between QCD and the HQET beyond tree
level. These are an expanded version of lectures presented during the Trieste
1994 Summer school on High Energy physics.


title: Physical Properties of Strangelets

abstract:
  Low-baryon number lumps of strange quark matter, strangelets, are presently
searched for in ultra-relativistic heavy-ion experiments at CERN and
Brookhaven. This paper gives an overview of the physical properties of
strangelets with emphasis on experimental signatures such as mass and charge.
Direct solutions of the Dirac equation with MIT bag model boundary conditions
are applied and compared to calculations based on a smoothed density of states,
as well as to simple mass-formulae based on the MIT bag. Most strangelet
properties can be understood within an approximation including bulk, surface
and curvature energy contributions.


title:
$\gamma \gamma \to \pi^0 \pi^0$ and $\eta \to \pi^0 \gamma \gamma$ at
  low energy within the Extended Nambu Jona-Lasinio Model

abstract:
  Within the Extended Nambu Jona-Lasinio model, we calculate the $O(p^6)$
counterterms entering the low-energy expansion of the $\gamma \gamma \to \pi^0
\pi^0$ and the $\eta \to \pi^0 \gamma \gamma$ amplitudes in Chiral Perturbation
Theory. For $\gamma \gamma \to \pi^0 \pi^0$ our results are compatible with
both the experimental data and the two-loop calculation using meson resonance
saturation. For the $\eta$ decay we find $\Gamma(\eta\to\pi^0
\gamma\gamma)=0.58\pm 0.3$ eV which is in agreement with experiment within one
standard deviation. We also give predictions for the neutral pion
polarizabilities and compare them with the results obtained from resonance
saturation.


title:
$E2/M1$ Ratio for the $\gamma N\rightarrow \Delta$ Transition in the
  Chiral Quark Soliton Model

abstract:
  We calculate the electric quadrupole to magnetic dipole transition ratio
$E2/M1$ for the reaction $\gamma N \ra \Delta(1232)$ in the chiral quark
soliton model. The calculated $E2/M1$ ratio is in a good agreement with the
very new experimental data. We obtain non-zero negative value for the electric
quadrupole $N-\Delta$ transition moment, which suggests an oblate deformed
charge structure of the nucleon or/and the delta isobar. Other observables
related to this quantity, namely the $N-\Delta$ mass splitting, the isovector
charge radius, and isovector magnetic moment, are properly reproduced as well.


title:
Sphaleron transitions in the Minimal Standard Model and the upper bound
  for the Higgs Mass

abstract:
  We calculate the dissipation of the baryon number after the electroweak phase
transition due to thermal fluctuations above the sphaleron barrier. We consider
not only the classical Boltzmann factor but also fermionic and bosonic one-loop
contributions. We find that both bosonic and especially fermionic fluctuations
can considerably suppress the transition rate. Assuming the Langer--Affleck
formalism for this rate, the condition that an initial baryon asymmetry must
not be washed out by sphaleron transitions leads, in the Minimal Standard Model
($\sin\theta_W=0$), to an upper bound for the Higgs mass in the range 60 to 75
GeV.


title: Soft SUSY Masses and the Dynamical Determination of the Gravitino Mass

abstract:
  We discuss in detail the possibility of determining dynamicaly the gravitino
mass $m_{3/2}$, which is related to the supersymmetry breaking scale, within
the minimal supersymmetric standard model (MSSM). Using the complete MSSM
spectrum, we minimize the vacuum energy including one-loop corrections and a
cosmological term of ${\cal O}(m_{3/2}^4)$ induced by the underlying
fundamental theory. We find that both terms are necessary to determine
dynamically the gravitino mass. Other useful constraints for the low energy
phenomenology are also obtained.


title: SYMMETRIES FOR VECTOR AND AXIAL-VECTOR MESONS

abstract:
  We discuss the possible symmetries of the effective lagrangian describing
interacting pseudoscalar-, vector-, and axial-vector mesons. Specific choices
of the parameters give rise to an $[SU(2)\otimes SU(2)]^3$ symmetry. This
symmetry can be obtained either {\it \'a la} Georgi, with all states in the
spectrum remaining massless, or in a new realization, implying decoupling of
the pseudoscalar bosons from degenerate vector and axial-vector mesons. This
second possibility, when minimally coupled with $SU(2)\otimes U(1)$ electroweak
gauge vector bosons, seems particularly appealing. All deviations in the
low-energy electroweak parameters are strongly suppressed, and the vector and
axial-vector states turn out to be quite narrow. A nearby strong electroweak
sector would then be conceivable and in principle it could be explored with
relatively low energy accelerators.


title:
Instantons and the endpoint of the lepton energy spectrum in charmless
  semileptonic $B$ decays

abstract:
  A recent calculation by Chay and Rey has shown that instantons may make a
significant contribution to the lepton energy spectrum near its endpoint. Using
an ansatz borrowed from the study of high energy baryon number violating
processes, we investigate whether these corrections could spoil the relation
between the nonperturbative contributions to this spectrum and to the photon
energy spectrum in radiative $B$ decays. We find, in general, that this
universality may well fail unless the spectrum is smeared over a region which
is considerably larger than had previously been thought necessary. This result
affects the possibility of performing a reliable measurement of $V_{ub}$ using
inclusive decays.


title: A one parameter representation for the Isgur-Wise function

abstract:
  We use a $1S$ lattice QCD heavy-light wavefunction to generate a single
parameter, model independent description of the Isgur-Wise function. Using
recent data we find the zero-recoil slope to be $\xi'(1)= -1.16\pm 0.17$, while
the second derivative turns out to be $\xi''(1)= 2.64\pm 0.74$.


title:
Hadronic Production of S-wave and P-wave Charmed Beauty Mesons via Heavy
  Quark Fragmentation

abstract:
  At hadron colliders the dominant production mechanism of $(\bar bc)$ mesons
with large transverse momentum is due to parton fragmentation. We compute the
rates and transverse momentum spectra for production of S-wave and P-wave
$(\bar b c)$ mesons at the Tevatron via the direct fragmentation of the bottom
antiquark as well as the Altarelli-Parisi induced gluon fragmentation. Since
all the radially and orbitally excited $(\bar b c)$ mesons below the $BD$
flavor threshold will cascade into the pseudoscalar ground state $B_c$ through
electromagnetic and/or hadronic transitions, they all contribute to the
inclusive production of $B_c$. The contributions of the excited S-wave and
P-wave states to the inclusive production of $B_c$ are 58 and 23\%,
respectively, and hence significant.


title: PREDICTING THE MASSES OF BARYONS CONTAINING ONE OR TWO HEAVY QUARKS

abstract:
  The Feynman-Hellmann theorem and semiempirical mass formulas are used to
predict the masses of baryons containing one or two heavy quarks. In
particular, the mass of the $\Lambda_b$ is predicted to be $5620 \pm 40$ MeV, a
value consistent with measurements.


title: Constraining Supergravity Scenarios through the $b\to s,\gamma$ Decay.

abstract:
  We evaluate the branching ratio BR($b\rightarrow s,\gamma$) in the minimal
supersymmetric standard model (MSSM), determining the corresponding
phenomenological restrictions on two attractive supergravity scenarios, namely
minimal supergravity and a class of models with a natural solution to the $\mu$
problem. We have included in the calculation some one--loop refinements that
have a substantial impact on the results. The numerical results show some
disagreements with part of the previous results in the literature, while they
are in agreement with others. For minimal supergravity the CLEO upper and lower
bounds put important restrictions on the scalar and gaugino masses in both
cases $\mu<0$ and $\mu>0$. For the other supergravity scenarios the relevant
CLEO bound is the upper one. It is stressed the fact that an eventual
improvement of the experimental bounds of order $10^{-4}$ would strengthen the
restrictions on the MSSM dramatically. This would be enough to discard these
supergravity scenarios with $\mu<0$ if no discrepancy is found with the
standard model prediction, while for $\mu>0$ there will remain low-energy
windows.


title: VIRTUES OF THE HAAG EXPANSION IN QUANTUM FIELD THEORY

abstract:
  I survey the use of the Haag expansion as a technique to solve quantum field
theories. After an exposition of the asymptotic condition and the Haag
expansion, I report the results of applying the Haag expansion to several
quantum field theories, including galilean-invariant theories, matter at finite
temperature (using the BCS model of superconductivity as an illustrative
example), the Nambu--Jona-Lasinio model and the Schwinger model. I conclude
with the outlook for further development of this method.


title: Chiral Lagrangians and Kaon CP-Violation

abstract:
  These lectures are an introduction to the subject of chiral effective
Lagrangians of the Standard Model and their applications, mostly in the sector
of non--leptonic kaon decays, with special emphasis on CP--violation. The first
lecture gives an introduction to the phenomenological description of the
$K^0-\bar{K}^0$ system and $K\ra \pi\pi$ decays. In the second lecture I give
an overview of the basic ideas behind the chiral perturbation theory ($\chi$PT)
--approach to hadron dynamics at low energies. The study of the weak
interactions of $K$--particles within the framework of $\chi$PT is the subject
of the third lecture. The fourth lecture is an overview of various models of
the QCD low--energy effective action which have been developed during the last
few years. The fifth lecture is dedicated to a discussion of the CP--violation
$\epsilon$ and $\epsilon'$ parameters, and to the study of the decay mode:
$K_{L}\ra \pi^{0}e^{+}e^{-}$.


title: DETERMINATION OF THE ELECTROWEAK CHIRAL-LAGRANGIAN PARAMETERS AT THE LHC

abstract:
  In this work we report on the results obtained in a detailed and systematical
study of the possibility to measure the parameters appearing in the electroweak
chiral lagrangian. The main novelty of our approach is that we do not use the
Equivalence Theorem and therefore we work explicitly with all the gauge boson
degrees of freedom.


title: Axion detection by ring lasers

abstract:
  A ring-laser experiment, similar to the Canterbury ring laser, to detect
axion- and {\sc qed}-induced vacuum birefringence is proposed. It uses a slowly
modulated magnetic field and a novel polarization geometry. Both axion coupling
and vacuum birefringence would modulate the Sagnac beat frequency. A null
result could place sensitive bounds on the axion mass and on two-photon
coupling.


title: ALGORITHMIC CALCULATION OF TWO-LOOP FEYNMAN DIAGRAMS

abstract:
  In a recent paper \cite{ft} a new powerful method to calculate Feynman
diagrams was proposed. It consists in setting up a Taylor series expansion in
the external momenta squared. The Taylor coefficients are obtained from the
original diagram by differentiation and putting the external momenta equal to
zero. It was demonstrated that by a certain conformal mapping and subsequent
resummation by means of Pad\'{e} approximants it is possible to obtain high
precision numerical values of the Feynman integrals in the whole cut plane. The
real problem in this approach is the calculation of the Taylor coefficients for
the arbitrary mass case. Since their analytic evaluation by means of CA
packages uses enormous CPU and yields very lengthy expressions, we develop an
algorithm with the aim to set up a FORTRAN package for their numerical
evaluation. This development is guided by the possibilities offered by the
formulae manipulating language FORM \cite{FORM}.


title: Chiral Condensate, Master Field and all that in $QCD_2 (N\to\infty)$

abstract:
  We discuss the various aspects of two-dimensional
$QCD_{2}(N\rightarrow\infty)$ (the 't Hooft model\cite{Hooft}). Our main
interest (motivated by the corresponding analysis in the four dimensional QCD)
is the vacuum structure of the theory. We use the very general methods in the
analysis, such as dispersion relations and duality in order to relate the known
spectrum of $QCD_2$ to the different vacuum characteristics. We explicitly
calculate (in terms of physical parameters like masses and matrix elements) the
chiral condensate as well as the mixed vacuum condensates: $$\la
0|\bar{q}(g\epsilon_{\mu\nu} G_{\mu\nu})^nq |0\ra \sim M_{eff}^{2n}\la
0|\bar{q} q |0\ra .$$ We interpret the factorization property for the mixed
vacuum condensates as a reminiscent of the master field at large $N$.


title: Heavy Meson Electromagnetic Mass Differences from QCD

abstract:
  We compute the electromagnetic mass differences of mesons containing a single
heavy quark in terms of measurable data using QCD-based arguments in
heavy-quark effective theory. We derive an unsubtracted dispersion relation
that shows that the mass differences are calculable in terms of the properties
of the lowest-lying physical intermediate states. We then consider the problem
in the large-$N$ limit, where $N$ is the number of QCD colors. In this limit,
we can write a kind of double-dispersion relation for the amplitude required to
determine the electromagnetic mass difference. We use this to derive analogs of
the Weinberg sum rules for heavy meson matrix elements valid to leading order
in $1/N$ and to $O(1/m_Q)$ in the heavy quark expansion. In order to obtain our
final result, we assume that the electromagnetic mass differences and sum rules
are dominated by the lowest-lying states in analogy with the situation for the
$\pi^+$--$\pi^0$ mass difference. Despite the fact that some of the matrix
elements appearing in our final result have not yet been accurately measured,
we can obtain useful numerical estimates: for example, we obtain $(M_{B^+} -
M_{B^0})^{EM} \simeq +1.8 \MeV$. We argue that our results are accurate to
about $30\%$.


title: TESTING SUPERSYMMETRY AT THE NEXT LINEAR COLLIDER

abstract:
  Up to now, almost all discussion of supersymmetry at future colliders has
been concerned with particle searches. However, if candidates for
supersymmetric particles are found, there is much more that we will want to
know about them. Supersymmetry predicts quantitative relations among the
couplings and masses of supersymmetric particles. We discuss the prospects for
testing such relations at a future $e^+e^-$ linear collider, using measurements
that exploit the availability of polarized beams. Precision tests from chargino
production are investigated in two representative cases, and sfermion and
neutralino processes are also discussed.


title:
PHENOMENOLOGICAL APPROACH TO UNPOLARIZED AND POLARIZED PARTON
  DISTRIBUTIONS AND EXPERIMENTAL TESTS

abstract:
  We recall our recent description of quark parton densities of the proton at
$Q^2=4 GeV^2$ in terms of Fermi-Dirac distributions parametrized with very few
free parameters. We have also proposed some simple assumptions to relate
unpolarized and polarized quark parton densities which lead to a fair
description of the spin-dependent structure functions $xg^p_1(x,Q^2)$ and
$xg^n_1(x,Q^2)$ at low $Q^2$. We will show the predictions we obtain after a
straightforward DGLAP $Q^2$ evolution and comparison in a much broader $x$ and
$Q^2$ range, with several recent and accurate deep-inelastic scattering data.
In particular, we will see that we get an excellent agreement with the sharp
rise of $F^{ep}_2(x,Q^2)$ for small $x$, recently observed at HERA. Finally, we
give several predictions for lepton pair and gauge boson production in $pp$ and
$pn$ collisions at high energies which will be tested in the future at RHIC.


title: NON-SINGLET STRUCTURE FUNCTIONS AT SMALL X

abstract:
  The small x behaviour of the non-singlet structure function is studied within
the double logarithmic approximation (DLA) of perturbative QCD. Since there is
neither $k_T$ nor $\theta$ ordering in the ladder Feynman graphs, the predicted
non-singlet quark densities for the HERA kinematical range ($x\sim 10^{-3}$)
exceed the values calculated from the small-$x$ approximation of the
conventional Altarelli-Parisi evolution by a factor up to ten.


title: ARE THERE STERILE NEUTRINOS IN THE FLUX OF SOLAR NEUTRINOS ON THE EARTH?

abstract:
  It is shown that the future SNO and Super-Kamiokande experiments, in which
high energy $^8\mathrm{B}$ neutrinos will be detected through the observation
of CC, NC and $\nu$--$e$ elastic scattering processes, could allow to reveal in
a model independent way the presence of sterile neutrinos in the flux of solar
neutrinos on the earth. Lower bounds for different averaged values of the
probability of transition of solar $\nu_e$'s into sterile states and for the
total flux of $^8\mathrm{B}$ neutrinos are derived in terms of measurable
quantities. The possibilities to reveal the presence of $\nu_\mu$ and/or
$\nu_\tau$ in the solar neutrino flux on the earth are also considered and the
case of transitions of solar $\nu_e$'s only into sterile states is discussed.
Some numerical results for a simple model with $\nu_e$--$\nu_s$ mixing are
given.


title:
Resummation of Renormalon Chains for Cross Sections and Inclusive Decay
  Rates

abstract:
  Recently, we have developed a formalism to evaluate QCD loop diagrams with a
single virtual gluon using a running coupling constant at the vertices. This
corresponds to an all-order resummation of certain terms (the so-called
renormalon chains) in a perturbative series and provides a generalization of
the scale-setting prescription of Brodsky, Lepage and Mackenzie. In its
original form, the method is applicable to Green functions without external
gluons and to euclidean correlation functions. Here we generalize the approach
to the case of cross sections and inclusive decay rates, which receive both
virtual and real gluon corrections. We encounter nonperturbative ambiguities in
the resummation of the perturbative series, which may hinder the construction
of the operator product expansion in the physical region. The origin of these
ambiguities and their relation to renormalon singularities in the Borel plane
is investigated by introducing an explicit infrared cutoff. The ratios $R_{e^+
e^-}$ and $R_\tau$ are discussed in detail.


title: HADRON SUBSTRUCTURE PROBED WITH HADRON BEAMS

abstract:
  In this talk, I focus on the quark-gluon structure of hadrons probed using
high-energy hadron beams. I start with a brief review on recent major
achievements in measuring parton distributions of the nucleon, pion, and kaon,
with hadron facilities at CERN and FNAL\@. Then I discuss a number of
outstanding questions and interesting physics issues in the field, and point
out their intellectual impact on nuclear physics as a whole. While advocating a
continuing exploitation of hadron beams at CERN and FNAL, I strongly emphasize
the role of a polarized RHIC, where a major nuclear physics program on the
structure of hadrons can thrive.


title: A [SU(6)]$^4$ FLAVOR MODEL WITHOUT MIRROR FERMIONS

abstract:
  We introduce a three family extension of the Pati-Salam model which is
anomaly-free and contains in a single irreducible representation the known
quarks and leptons without mirror fermions. Assuming that the breaking of the
symmetry admits the implementation of the survival hypothesis, we calculate the
mass scales using the renormalization group equation. Finally we show that the
proton remains perturbatively stable.


title: The profile of a nonstandard Higgs boson at the LHC

abstract:
  In a wide class of extensions of the Standard Model there is a scalar
resonance with the quantum numbers of the usual Higgs boson but with different
couplings to fermions and gauge bosons. Using an effective Lagrangian
description, we examine the phenomenology of such a generic nonstandard Higgs
boson at the LHC. In particular, we determine the circumstances under which
such a particle can be observed in its $ZZ$ decay mode and distinguished from
the Higgs boson of the Standard Model. We briefly comment on the energy scale
effectively probed at the LHC, if the nonstandard nature of an observed Higgs
particle can be asserted.


title: NEUTRINOS FROM PRIMORDIAL BLACK HOLES

abstract:
  The emission of particles from black holes created in the early Universe has
detectable astrophysical consequences. The most stringent bound on their
abundance has been obtained from the absence of a detectable diffuse flux of
100 MeV photons. Further scrutiny of these bounds is of interest as they, for
instance, rule out primordial black holes as a dark matter candidate. We here
point out that these bounds can, in principle, be improved by studying the
diffuse cosmic neutrino flux. Measurements of near-vertical atmospheric
neutrino fluxes in a region of low geomagnetic latitude can provide a
competitive bound. The most favorable energy to detect a possible diffuse flux
of primordial black hole origin is found to be a few MeV. We also show that
measurements of the diffuse $\nu _\tau$ flux is the most promising to improve
the existing bounds deduced from gamma-ray measurements. Neutrinos from
individual black hole explosions can be detected in the GeV-TeV energy region.
We find that the kilometer-scale detectors, recently proposed, are able to
establish competitive bounds.


title:
Pion condensation during the hadronization of the quark-gluon plasma in
  ultra-relativistic heavy-ion collisions.

abstract:
  Using a simple kinetic model we study whether a pion condensate can be formed
during the hadronization of the quark-gluon plasma in ultrarelativistic
heavy-ion collisions. If hadronization proceeds fast and the pion effective
mass is close to zero, some pions condense into the zero momentum state. On the
other hand, for the pion effective mass equal to the vacuum one or larger no
onset of the Bose-Einstein condensation is observed. The constraints on the
condensation process coming from the requirement of the entropy increase are
discussed in detail.


title: Quarkonium production in hadronic collisions

abstract:
  We summarize the theoretical description of charmonium and bottonium
production in hadronic collisions and compare it to the available data from
hadron-nucleon interactions. With the parameters of the theory established by
these data, we obtain predictions for quarkonium production at RHIC and LHC
energies.


title:
Phenomenological determination of polarized quark distributions in the
  nucleon

abstract:
  We present a fit to spin asymmetries which gives polarized quark
distributions. These functions are closely related to the ones given by the
newest Martin, Roberts and Stirling fit for unpolarized structure functions.
The integrals of polarized distributions are discussed and compared with the
corresponding quantities obtained from neutron and hyperon $\beta$-decay data.
We use the combination of proton and neutron spin asymmetries in order to
determine the coefficients of our polarized quark distributions. Our fit shows
that phenomenologically there is no need for taking gluonic degrees of freedom
into account.


title: Phase Transitions and Mass Generation in 2+1 Dimensions

abstract:
  The possibility that the epsilon expansion can predict the order of phase
transitions in three dimensional field theories is examined. For a Hermitean
matrix-valued order parameter, the epsilon expansion predicts fluctuation
induced first order phase transitions. We analyze two 2+1-dimensional quantum
field theories which exhibit spontaneous symmetry breaking and have martix
order parameters. Using the large $N$ expansion, we show that these models
exhibit second order transitions and discuss the implications for the chiral
symmetry breaking transition in 2+1-dimensional QCD for a critical number of
quark flavors.


title: New Third-family Flavor Physics: Vertex Corrections

abstract:
  As described previously, a new massive gauge boson (X) coupling only to the
third family produces a tantalizing pattern of deviations away from the
standard model. These include increasing Gamma_b/Gamma_h and decreasing the
alpha_s(M_Z) extracted from Gamma_h/Gamma_ell . We review the status of these
X-Z mixing effects. We then calculate X boson induced vertex corrections to Z
partial decay widths and to ttbar production in ppbar colliders.


title: Properties of the a1 Meson from Lattice QCD

abstract:
  We determine the mass and decay constant of the $a_1$ meson using Monte Carlo
simulation of lattice QCD. We find $M_{a_1} = 1250 \pm 80$ MeV and $f_{a_1} =
0.30 \pm 0.03 ~({\rm GeV})^2$, in good agreement with experiment.


title: Nonleptonic Two-Body Decays of D Mesons in Broken SU(3)

abstract:
  Decays of the D mesons to two pseudoscalars, to two vectors, and to
pseudoscalar plus vector are discussed in the context of broken flavor SU(3). A
few assumptions are used to reduce the number of parameters. Amplitudes are fit
to the available data, and predictions of branching ratios for unmeasured modes
are made.


title: Wavepacket Dynamics in Yang-Mills Theory

abstract:
  We discuss the results of numerical simulations of colliding wavepackets in
$SU(2)$ Yang--Mills theory. We investigate their behavior as a function of
amplitude and momentum distribution. We find regions in our parameter space in
which initial wave packets scatter into final configurations with dramatically
different momentum distributions. These results constitute new classical
trajectories with multiparticle boundary conditions. We explain their relevance
for the calculation of scattering amplitudes in the semiclassical
approximation. Finally, we give directions for future work.


title:
Dual Ginzburg-Landau Theory for Quark Confinement and Dynamical
  Chiral-Symmetry Breaking

abstract:
  Nonperturbative features of QCD are studied using the dual Ginzburg-Landau
(DGL) theory with QCD-monopoles. The linear quark potential appears in the
QCD-monopole condensed vacuum. We find that QCD-monopole condensation plays an
essential role to the dynamical chiral-symmetry breaking. We also investigate
the QCD phase transition at finite temperature in the DGL theory.


title:
QCD Phase Transition at Finite Temperature in the Dual Ginzburg-Landau
  Theory

abstract:
  We study the pure-gauge QCD phase transition at finite temperatures in the
dual Ginzburg-Landau theory, an effective theory of QCD based on the dual Higgs
mechanism. We formulate the effective potential at various temperatures by
introducing the quadratic source term, which is a new useful method to obtain
the effective potential in the negative-curvature region. Thermal effects
reduce the QCD-monopole condensate and bring a first-order deconfinement phase
transition. We find a large reduction of the self-interaction among
QCD-monopoles and the glueball masses near the critical temperature by
considering the temperature dependence of the self-interaction. We also
calculate the string tension at finite temperatures.


title: Dual Higgs Mechanism for Quarks in Hadrons

abstract:
  We study nonperturbative features of QCD using the dual Ginzburg-Landau (DGL)
theory, where the color confinement is realized through the dual Higgs
mechanism brought by QCD-monopole condensation. The linear confinement
potential appears in the QCD-monopole condensed vacuum. We study the infrared
screening effect to the confinement potential by the light-quark pair creation,
and derive a compact formula for the screened quark potential. We study the
dynamical chiral-symmetry breaking (D$\chi $SB) in the DGL theory by solving
the Schwinger-Dyson equation. QCD-monopole condensation plays an essential role
to D$\chi $SB. The QCD phase transition at finite temperature is studied using
the effective potential formalism in the DGL theory. We find the reduction of
QCD-monopole condensation and the string tension at high temperatures. The
surface tension is calculated using the effective potential at the critical
temperature. The DGL theory predicts a large mass reduction of glueballs near
the critical temperature. We apply the DGL theory to the quark-gluon-plasma
(QGP) physics in the ultrarelativistic heavy-ion collisions. We propose a new
scenario of the QGP formation via the annihilation of color-electric flux tubes
based on the attractive force between them.


title: INCLUSIVE PARTICLE PRODUCTION IN $\pbp$ COLLISIONS

abstract:
  We calculate the inclusive production of charged hadrons in $\pbp$ collisions
to next-to-leading order (NLO) in the QCD improved parton model using a new set
of NLO fragmentation functions for charged pions and kaons. We predict
transverse-momentum distributions and compare them with experimental data from
the CERN S$\pbp$S Collider and the Fermilab Tevatron.


title: Generalized Gaussian Effective Potential: Thermal Corrections

abstract:
  We evaluate the thermal corrections to the generalized Gaussian effective
potential. We carry out the calculations of the lowest order corrections in the
case of self-interacting scalar fields in one and two spatial dimensions, and
study the restoration of the symmetry at high temperatures.


title:
Current s-Quark Mass Corrections to the Form Factors of D-Meson
  Semileptonic Decays

abstract:
  The infinite mass effective theory, when a heavy quark mass tends to
infinity, and Chiral perturbation theory at the quark level, based on the
extended Nambu -- Jona -- Lasinio model with linear realization of chiral
$U(3)\times U(3)$ symmetry, are applied to the calculation of current $s$ --
quark mass corrections to the form factors of the $D\to\bar K~e^+~\nu_e$ and
$D\to\bar K^{\ast}~e^+~\nu_e$ decays. These corrections turn out to be quite
significant, of the order of $7-20\%$. The theoretical results are compared
with experimental data.


title: Testing $CP$ in the Bjorken process

abstract:
  In a more general electroweak theory, there could be Higgs particles that are
odd under $CP$, and also Higgs-like particles which are not eigenstates of
$CP$. We discuss distributions which for the Bjorken process are sensitive to
the $CP$ parity. Correlations among momenta of the initial electron and
final-state fermions yield this kind of information. We discuss also
observables which may demonstrate presence of $CP$ violation and identify a
phase shift $\delta$ which is a measure of the strength of $CP$ violation in
the Higgs-vector-vector coupling, and which can be measured directly in the
decay distribution. We present Monte Carlo data on the expected efficiency, and
conclude that it is relatively easy to determine whether the produced particle
is even or odd under $CP$. However, observation of any $CP$ violation would
require a very large amount of data.


title:
INVERSE NEUTRINOLESS DOUBLE-BETA DECAY IN GAUGE THEORIES WITH CP
  VIOLATION

abstract:
  We investigate the reactions $e^-e^- \rightarrow W_i^-W_j^-$ for various
gauge bosons production processes in the frame of the standard model with
additional right-handed neutrinos and the Left-Right symmetric model. The
present bounds on the various model parameters are taken into account. The
question of the cross section behaviour for large energy and the CP violation
problems are discussed.


title: Double chiral logs in the $\pi \pi$ scattering amplitude

abstract:
  By using the Renormalization Group Equations in Chiral Perturbation Theory,
one can calculate the double chiral logs that appear at two loops in any matrix
element. We calculate them in the $\pi \pi$ scattering amplitude, where they
represent the potentially largest two loop contribution. It is shown that their
correction is reasonably small.


title:
Short and Long Distance Interplay in Inclusive $ B \to X_d \gamma $
  Decays

abstract:
  We analyze the short and long distance contributions to inclusive $B
\rightarrow X_d \gamma$ decay, paying particular attention to the dependence on
the Cabibbo-Kobayashi-Maskawa parameter $V_{td}$. We discuss penguin diagrams
with internal $u$ and $c$ quarks in the framework of the effective field
theory. We also estimate the size of possible long range contributions by using
vector meson dominance.


title:
The Center-of-Mass of A Few-Body Quantum System In An Effective Central
  Field

abstract:
  The center-of-mass(CM) of a few-body quantum system with a central field is
discussed. If the particles are in the designative eigenstates, the CM
coordinates of the system can be well-defined. In the CM bag model as well as
in other models with central fields, the CM-freedom separation rule and
effective nucleon electro-magnetic currents can be presented without any
undetermined parameter.


title:
PHYSICS OF $Q^2$-DEPENDENCE IN THE NUCLEON'S $G_1(x,Q^2)$ STRUCTURE
  FUNCTION SUM RULE

abstract:
  I discuss in this talk the physics of the $Q^2$ dependence of the
$G_1(x,Q^2)$ structure function sum rule. For $Q^2>3$ GeV$^2$, the $Q^2$
variation is controlled by pure QCD radiative corrections. For $0.5<Q^2<3$
GeV$^2$, the twist-four contribution becomes significant, but stays
perturbative. For $Q^2$ below $\sim 0.05$, the sum rule is determined by
low-energy theorems. The rapid change of the sum rule between 0.05 and 0.5
GeV$^2$ signals the transition between parton and hadron degrees of freedom.


title:
Gluon Production from Non-Abelian Weizs\"acker-Williams Fields in
  Nucleus-Nucleus Collisions

abstract:
  We consider the collisions of large nuclei using the theory of McLerran and
Venugopalan. The two nuclei are ultra-relativistic and sources of non-abelian
Weizs\"acker-Williams fields. These sources are in the end averaged over all
color orientations locally with a Gaussian weight. We show that there is a
solution of the equations of motion for the two nucleus scattering problem
where the fields are time and rapidity independent before the collision. After
the collision the solution depends on proper time, but is independent of
rapidity. We show how to extract the produced gluons from the classical
evolution of the fields.


title: Production of Heavy Quarks Close to Threshold

abstract:
  We calculate production by vector and axial currents of heavy quark pairs
($c\bar{c}$, $b\bar{b}$, $t\bar{t}$) close to threshold. We take into account
strong interaction contributions (including radiative corrections and leading
nonperturbative effects) by using the Fermi-Watson final state interaction
theorem. We use the results obtained to compare with experiment for open
production of $c\bar{c}$, $b\bar{b}$ near threshold, and to give a reliable
estimate of the so-called ``threshold effects'' contribution to vector and
axial correlators, for $t \bar{t}$, $i.e.$, the contribution of regions close
to $4 m_t^2 $ to $\Pi(t)$, for small values of $t$ ($ 0 < t
\lower2pt\hbox{$\lesssim$} M_Z^2 $).


title: Corrections of order ${\cal O}(G_F M_t^2 \as^2)$ to the $\rho$ parameter

abstract:
  The three-loop QCD corrections to the $\rho$ parameter from top and bottom
quark loops are calculated. The result differs from the one recently calculated
by Avdeev et al. As function of the pole mass the numerical value is given by
$\drho=\frac{3G_F M_t^2}{8\sqrt{2}\pi^2}(1- 2.8599 \api - 14.594 (\api)^2 )$.


title: CONFINEMENT IN RELATIVISTIC POTENTIAL MODELS

abstract:
  In relativistic potential models of quarkonia based on a Dirac-type of
equation with a local potential there is a sharp distinction between a linear
potential V which is vector-like and one which is scalar-like: There are
normalizable solutions for a scalar-like V but not for a vector-like V. It is
pointed out that if instead one uses an equation of the no-pair type, which is
more natural from the viewpoint of field theory, this somewhat bizarre
difference disappears.


title:
Large CP Asymmetries in $B^{\pm}\to\eta_c(\chi_{c0})\pi^{\pm}$ from
  $\eta_c(\chi_{c0})$ Width

abstract:
  We study CP asymmetries in $B^{\pm}\to h\pi^{\pm}$ decays, where the hadronic
states $h=\rho\rho, K\Kbar\pi$, $\pi^+\pi^-K^+K^-$, etc., and $h=\pi^+\pi^-,
K^+K^-, 2(\pi^+\pi^-)$, etc., are taken on the resonances $\eta_c$ and
$\chi_{c0}$, respectively. The relatively large $\eta_c$ and $\chi_{c0}$ decay
widths, of about 10$-$15 MeV, provide the necessary absorptive phase in the
interference between the resonance (going through $b\to c\cbar d$) and the
background (through $b\to u\ubar d$) contributions to the amplitude. Large
asymmetries of order 10$\%$ or more are likely in some modes.


title: Heavy Majorana Neutrino Decays and CP-Parity Violation

abstract:
  In the framework of the left-right symmetric model the CP-parity violation
has been studied in heavy Majorana neutrino decays $N\rightarrow e^{\mp}
\mu^{\pm} n$. The numerical estimates of CP-asymmetry for different masses of
neutrino and $W_{R}^{\pm}$-boson were obtained. The possibility to detect this
phenomenon at high energy colliders is mentioned.


title: Strong and Weak Interactions of Strange Hadrons

abstract:
  I review hadronic processes involving strange hadrons, especially hyperons
from the quark structure point of view. The strong interaction of quarks
expects several important new features when the strangeness is introduced upon
the non-strange degrees of freedom. I concentrate on the instanton induced
interaction, effects of the Pauli principle for strangeness and the nonleptonic
weak interaction of strangeness. The single hadron as well as the two baryon
systems including the $H$ dibaryon and other exotic hadronic systems with
strangeness are studied in this context.


title: CONSTRAINTS FROM LEPTON UNIVERSALITY AT THE Z PEAK ON UNIFIED THEORIES

abstract:
  We suggest the use of a universality-breaking observable based on lepton
asymmetries as derived from the left-right asymmetry and the $\tau$
polarization at the $Z$ peak, which can efficiently constrain the parameter
space of unified theories. The new observable is complementary to the leptonic
partial width differences and it depends critically on the chirality of a
possible non-universal $Z$-boson coupling to like-flavour leptons. The LEP/SLC
potential of probing universality violation is discussed in representative
low-energy extensions of the Standard Model (SM) that could be derived by
supersymmetric grand unified theories, such as the SM with left-handed and/or
right-handed neutral isosinglets, the left-right symmetric model, and the
minimal supersymmetric SM.


title:
A Symmetry Pattern of Maximal CP-Violation and a Determination of the
  Unitarity Triangle

abstract:
  Within a specific texture of the quark mass matrix the notion of a maximal
violation of the $CP$ symmetry can be defined. The experimental constraints
from weak decays imply that in reality one is close to the case of maximal $CP$
violation, which vanishes as the mass of the $u$--quark approaches zero. The
unitarity triangle of the Cabibbo--Kobayashi--Maskawa matrix elements is
determined. It is related to the triangle relating the Cabibbo angle to the
quark mass ratios in the complex plane. The angle $\alpha $ describing the $CP$
violation in the decay $B_d \rightarrow \pi^+ \pi^-$ is close to 90$^{\circ }$.


title:
Hadronic contributions to $(g-2)$ of the leptons and to the effective
  fine structure constant $\alpha(M_Z^2)$

abstract:
  The hadronic contributions to the anomalous magnetic moments of the leptons
and to the effective fine structure constant at the Z-mass are reevaluated
using all presently available $e^+ e^-$ data.


title:
Empirical regularities in the $x$--dependence of nuclear J/Psi
  suppression

abstract:
  The measured ratios $R(x,A_1/A_2)$ for $J/\Psi$, $\Psi'$ and $\mu^+\mu^-$
production on two different targets $A_1, A_2$ as a function of the fractional
momentum $x$ of the final state are well fit with a very simple functional form
having three adjustable parameters. An empirical relation is found between the
three parameters of the fit. The deduced $J/\Psi$ absorption cross sections
$\sigma_{abs}$ cluster around two values of which only $\sigma_{abs} = 5.8 \pm
0.2$ mb seems acceptable.


title:
Resummation of $(\beta_0 \alpha_s)^n$ Corrections in QCD: Techniques and
  Applications to the $\tau$ Hadronic Width and the Heavy Quark Pole Mass

abstract:
  We propose to resum exactly any number of one-loop vacuum polarization
insertions into the scale of the coupling of lowest order radiative
corrections. This makes maximal use of the information contained in one-loop
perturbative corrections combined with the one-loop running of the effective
coupling and provides a natural extension of the familiar BLM scale-fixing
prescription to all orders in the perturbation theory. It is suggested that the
remaining radiative corrections should be reduced after resummation. In this
paper we implement this resummation by a dispersion technique and indicate a
possible generalization to incorporate two-loop evolution. We investigate in
some detail higher order perturbative corrections to the $\tau$ decay width and
the pole mass of a heavy quark. We find that these corrections tend to reduce
$\alpha_s(m_\tau)$ determined from $\tau$ decays by approximately 10\% and
increase the difference between the bottom pole and $\MS$-renormalized mass by
30\%.


title: A MASTER FORMULA APPROACH TO CHIRAL SYMMETRY BREAKING

abstract:
  We find that various results of current algebra at tree level and beyond can
be directly obtained from a master formula, without use of chiral perturbation
theory or effective Lagrangians. Application is made to $\pi \pi$ scattering,
where it is shown that the bulk of the $\rho$ contribution can be determined in
a model independent way.


title:
Dimensional Reduction and Quantum-to-Classical Reduction at High
  Temperatures

abstract:
  We discuss the relation between dimensional reduction in quantum field
theories at finite temperature and a familiar quantum mechanical phenomenon
that quantum effects become negligible at high temperatures. Fermi and Bose
fields are compared in this respect. We show that decoupling of fermions from
the dimensionally reduced theory can be related to the non-existence of
classical statistics for a Fermi field.


title: New Universality Classes for Quantum Critical Behavior

abstract:
  We use the epsilon expansion to explore a new universality class of second
order quantum phase transitions associated with a four-dimensional Yukawa field
theory coupled to a traceless Hermitean matrix scalar field. We argue that this
class includes four-fermi models in $2<D<4$ dimensions with $SU(N_F)\times
U(N)$ symmetry and a U(N) scalar, $SU(N_F)$ iso-vector 4-fermi coupling. The
epsilon expansion indicates that there is a second order phase transition for
$N\geq N^*(N_F)$, where $N^*(N_F)\simeq.27N_F$ if $N_F\to\infty$.


title: Predicting the neutrino-spectrum in SUSY-SO(10)

abstract:
  We present a systematic search for SUSY-SO(10) models which predict the
neutrino properties. The models are based on the five sets of quark mass
matrices, with texture zeros, discussed recently by Roberts, Ramond and Ross.
We found 8 such neutrino textures three of which can solve the solar neutrino
problem. The latter have tau-neutrino masses of few eV i.e. relevant for
cosmology and $\nu_{\tau} - \nu_{\mu}$ mixing angles that can be observed by
the CHORUS, NOMAD and P803 experiments.


title: Chiral Symmetry and Scalar Meson in Hadron and Nuclear Physics

abstract:
  After giving a short introduction to the Nambu-Jona-Lasinio model with an
anomaly term, we show the importance of the scalar-scalar correlation in the
low-energy hadron dynamics, which correlation may be summarized by a
scalar-isoscalar meson, the sigma meson. The discussion is based on the chiral
quark model with the sigma-meson degrees of freedom. Possible experiments are
proposed to produce the elusive meson in a nucleus and detect it. In relation
to a precursory soft mode for the chiral transition, the reason is clarified
why the dynamic properties of the superconductor may be described by the
diffusive time-dependent Ginzburg-Landau (TDGL) equation. We indicate the
chiral symmetry plays a significant role also in nuclei; one may say that the
stability of nuclei is due to the chiral symmetry of QCD.


title:
Can a mass inversion save solar neutrino oscillations from the Los
  Alamos neutrino?

abstract:
  In the light of the $\nu_\mu\to\nu_e$ neutrino oscillations which may have
been observed at the LSND experiment we explore the consequences of two
inverted mass schemes where solar neutrino oscillations occur between $\nu_e$
and $\nu_\tau$. The favored LSND value $\Delta m^2=6\,\eV^2$ leads to
$m_{\nu_e}\approx m_{\nu_\tau}\approx 2.5\,\eV$ and $m_{\nu_\mu}\approx0$ so
that cosmology can benefit from a recently proposed ``cold plus hot dark
matter'' structure formation scenario with two equal mass light neutrinos
(C$\nu^2$DM). Solar neutrino oscillations ($\nu_e\to\nu_\tau$) can occur with
one of the large mixing angle solutions so that a serious conflict with
$\beta\beta$ decay Majorana mass limits is avoided without invoking Dirac
masses. However, there is a problem with the SN~1987A signal because of
resonant $\anti\nu_e\leftrightarrow\anti\nu_\mu$ oscillations which are
expected to cause far higher $\anti\nu_e$ energies at the IMB and Kamiokande~II
detectors than have been observed. A small value $\Delta m^2=0.5\,\eV^2$ at
LSND, which allows for a relatively large $\nu_e$-$\nu_\mu$ mixing angle
without conflicting with the KARMEN and BNL-E776 experiments, would indicate
$m_{\nu_e}\approx m_{\nu_\tau}\approx 1.62\,\eV$ and
$m_{\nu_\mu}\approx1.77\,\eV$. This scheme of C$\nu^3$DM maintains, and even
may improve, the essential cosmological model implications for large-scale
structure, leaving no conflict with SN r-process nucleosynthesis. It may
improve the discordance between the SN~1987A neutrino spectra inferred from
Kamiokande~II and IMB.


title:
An effective field theory approach to the QCD corrections to the
  large-$m_t$ $Zb\bar b$ vertex

abstract:
  Using effective field theory techniques we discuss the QCD corrections to the
large-$m_t$ contributions to the process $Z\rightarrow b \bar b$. In particular
we obtain the $\a$ correction to the non-universal $\log m_t$ contribution to
the $Zb\bar b$ vertex.


title: Gauge invariant effective action for high-energy processes in QCD

abstract:
  The Born amplitudes for quasi-multi-Regge kinematics of produced gluons are
constructed in accordance with the Feynman rules including apart from usual
Yang-Mills vertices also an infinite number of induced vertices. The new
vertices describe the interaction of physical gluons produced in direct
channels with the reggeized gluons propagating in crossing channels. The
nonlinear gauge invariant effective action reproducing these Feynman rules is
constructed with the use of the Wilson contour integrals. After integrating
over the physical degrees of freedom the reggeon action is derived.


title: Learning about the strongly interacting symmetry breaking sector at LHC

abstract:
  In the present work we study the predictions for $WZ$ and $ZZ$ production at
LHC with the Electroweak Chiral Lagrangian (EChL) approach. Our analysis will
be focused on the less favored case from the experimental point of view, in
which the predictions for the gauge bosons scattering amplitudes are considered
in the low energy range where, by construction of the low energy approach, they
reveal no resonant behavior. The study includes the complete set of amplitudes
for all the polarization states of the initial and/or final gauge bosons and
makes no use of the Equivalence Theorem. We express the results in terms of the
range of values of the chiral parameters that will be accessible at LHC.


title:
Equation of State and Temperature of First Heavy Particles Arising in
  the Universe at the Grand Unification Scale,

abstract:
  We consider first heavy particles with masses $M\sim M_{GUT}$ which arise in
the Universe during phase transitions at the Grand Unification scale. Using
statistical mechanics approach we show that they behave like ideal quantum
degenerate Bose gas which has the temperature of the Hawking thermal radiation
due to presence of the de Sitter event horizon. The equation of state for both
scalar and gauge bosons is presented including the coupling constant at the
Grand Unification scale.


title: SU(3) Corrections to B -> D l nu Form Factors at O(1/M)

abstract:
  We compute the O(1/M,m_s) heavy quark and SU(3) corrections to B_s -> D_s e
nu form factors. In the limit of vanishing light quark mass, B_s -> D_s e nu
form factors are given in terms of the the B -> D e nu form factors, the
leading order chiral parameter g, and two O(1/M) chiral parameters $g_1$ and
$g_2$. All the chiral parameters can be extracted, in principle, from other
heavy meson decays. Analytic counterterms proportional to the strange quark
mass are presented for completeness, but no predictive power remains when they
are included. Anomalously large loop corrections warn of poor convergence of
the heavy quark chiral symmetry expansion for these processes. This suggests
that naive extrapolations of B \to D form factors relying on heavy quark and
chiral symmetries, as often used in monte carlo simulations of lattice QCD, may
incur large errors.


title:
Invariant mass distributions for heavy quark-antiquark pairs in deep
  inelastic electroproduction

abstract:
  We have completed the ${\cal O}(\alpha_s)$ QCD corrections to exclusive heavy
quark-antiquark distributions in deep inelastic electroproduction and present
here the differential distributions in the masses of charm-anticharm and
bottom-antibottom pairs at the electron-proton collider HERA.


title: REDUCTION OF THE N-COMPONENT SCALAR MODEL AT TWO LOOP LEVEL

abstract:
  Dimensional reduction of high temperature field theories improves IR features
of their perturbative treatment. A crucial question is, what three-dimensional
theory is representing the full system the most faithful way. Careful
investigation of the induced 3-dimensional counterterm structure of the finite
temperature 4D O(N) symmetric scalar theory at 2-loop level leads to proposing
the presence of non-local operators in the effective theory. On scales beyond
${\cal O}(T^{-1})$, the scaling behavior of the couplings, consequently,
deviates from the usual three-dimensional scaling characteristic for
superrenormalizable theories.


title:
In-medium effective chiral lagrangians and the pion mass in nuclear
  matter

abstract:
  We argue that the effective pion mass in nuclear matter obtained from chiral
effective lagrangians is unique and does not depend on off-mass-shell
extensions of the pion fields as e.g. the PCAC choice. The effective pion mass
in isospin symmetric nuclear matter is predicted to increase slightly with
increasing nuclear density, whereas the effective time-like pion decay constant
and the magnitude of the density-dependent quark condensate decrease
appreciably. The in-medium Gell-Mann-Oakes-Renner relation as well as other
in-medium identities are studied in addition. Finally, several constraints on
effective lagrangians for the description of the pion propagation in isospin
symmetric, isotropic and homogenous nuclear matter are discussed. (Talk
presented at the workshop ``Hirschegg '95: Hadrons in Nuclear Matter'',
Hirschegg, Kleinwalsertal, Austria, January 16-21, 1995)


title: New Supersymmetric Contributions to Neutrinoless Double Beta Decay.

abstract:
  The neutrinoless double beta ($\znbb$) decay is analyzed within the Minimal
Supersymmetric Standard Model with explicit R-parity violation (\rp MSSM). We
have found new supersymmetric contributions to this process and give the
complete set of relevant Feynman diagrams. Operators describing $0^+
\longrightarrow 0^+$ nuclear transitions induced by the supersymmetric
interactions of the \rp MSSM are derived. These operators can be used for
calculating the $\znbb$ decay rate applying any specific nuclear model wave
functions.


title: Semihard Hadron Processes and Quark-gluon String Model

abstract:
  A new approach to the analysis of soft and semihard hadron processes is
suggested. In the frame of the Quark-Gluon String Model the interaction of
valence quarks and diquarks and sea quarks (antiquarks) of colliding hadrons is
taken into account. This one is calculated as the exchange by one
nonpertubative gluon, i.e., the cut-off parameter in the gluonic propagator is
included. This one allows us to analise the inclusive hadron spectra in hadron
collisions at transverse momenta up to 3-4 Gev/c.


title:
THE QUANTUM CORRELATION R_b-R_c IN THE MSSM: MORE HINTS OF
  SUPERSYMMETRY?

abstract:
  We study the correlation of quantum effects on the ratios R_b and R_c within
the framework of the MSSM. While in the SM the quantity R_b is in discrepancy
with experiment at the 2 \sigma level from below, and R_c differs from the
experimental result at the 1.5 \sigma level from above, the theoretical
prediction for both observables could simultaneously improve in the MSSM,
provided that \tan\beta is large enough (\tan\beta\sim m_t/m_b) and there
exists a light supersymmetric pseudoscalar Higgs, and also a light stop and a
light chargino, all of them in the 50 GeV ballpark. In view of the masses
predicted for these SUSY particles, persistence of the `R_b-R_c crisis' in the
next run of experiments would not only suggest indirect evidence of SUSY, but
should also encourage direct finding of SUSY at LEP 200. We also point out the
consistency of this picture with other observables and the intriguing
possibility that this Z-physics scenario might allow getting a hint of SUSY at
Tevatron through the simple observation of t\to H^{+}b.


title: Possible dynamical determination of $m_t$, $m_b$ and $m_{\tau}

abstract:
  Motivated by four-dimensional superstring models, we consider the possibility
of treating the Yukawa couplings of the Minimal Supersymmetric Standard Model
(MSSM) as dynamical variables of the effective theory at the electroweak scale.
Assuming bottom-tau unification, we concentrate on the top and bottom Yukawa
couplings, and find that minimizing the effective potential drives them close
to an effective infrared fixed line. Requiring an acceptable bottom-top mass
ratio leads in principle to an additional constraint on the MSSM parameter
space. As a by-product, we give new approximate analytical solutions of the
renormalization group equations for the MSSM parameters.


title: Hard diffraction in hadron--hadron interactions and in photoproduction

abstract:
  Hard single diffractive processes are studied within the framework of the
triple--Pomeron approximation. Using a Pomeron structure function motivated by
Regge--theory we obtain parton distribution functions which do not obey
momentum sum rule. Based on Regge-- factorization cross sections for hard
diffraction are calculated. Furthermore, the model is applied to hard
diffractive particle production in photoproduction and in $p\bar{p}$
interactions.


title:
$K_{L e5}$ decay as a background in search for $K_{L} \to \pi^{0}
  \mu^{\pm} e^{\mp}$

abstract:
  We consider a process $K_{L e5} ( K_{L} \rightarrow \pi^{0} \pi^{0} \pi^{\pm}
e^{\mp} \nu )$ as a standard model background to the experiment $K_{L}
\rightarrow \pi^{0} \mu^{\pm} e^{\mp}$, which seeks for possible violation of
lepton family number. Using the lowest order chiral lagrangian, we find that
the branching ratio for $K_{L} \rightarrow \pi^{0} \pi^{0} \pi^{\pm} e^{\mp}
\nu $ to be $6.2 \times 10^{-12}$. A similar decay $K_{L} \rightarrow \pi^{\mp}
\pi^{\mp} \pi^{\pm} e^{\pm} \nu$ has a branching ratio, $1.7 \times 10^{-11}$.


title: THERMODYNAMICS OF THE ELECTROWEAK PHASE TRANSITION

abstract:
  We discuss several general aspects of the free energy of the standard model
at high temperatures. In particular the Clausius-Clapeyron equation is shown to
yield a relation between the latent heat and the jump in the order parameter.
The free energy is calculated as function of temperature in resummed
perturbation theory to two-loop order. A new resummation procedure is proposed
in which the symmetric phase and the Higgs phase are treated differently. A
quantitative description of the phase transition is achieved for Higgs masses
below $\sim 70$ GeV. The results are found to be in agreement with recent
numerical simulations on large lattices. The phase transition provides no
evidence for strong non-perturbative effects in the symmetric phase.


title: HARD PROBES OF DENSE MATTER

abstract:
  Direct probes for the QGP must be hard enough to resolve sub-hadronic scales
($\ll \la^{-1}$) and distinguish confined and deconfined media. This can be
achieved by fast colour charges (jets) and heavy quark resonances (quarkonia).
After a general survey, we study quarkonia as confinement probe and show in
particular that confined matter is transparent, deconfined matter opaque to
\J's.


title:
QCD Sum Rule Calculation of Twist-4 Corrections to Bjorken and
  Ellis-Jaffe Sum Rules

abstract:
  We calculate the twist-4 corrections to the integral of $g_1(x,Q^2)$ in the
framework of QCD sum rules using an interpolating nucleon field which contains
explicitly a gluonic degree of freedom. This information can be used together
with previous calculations of the twist-3 contribution to the second moment of
$g_2(x)$ to estimate the higher-twist corrections to the Ellis-Jaffe and
Bjorken sum rules. We get $f^{(2)}(proton) = -0.037 \pm 0.006$ and
$f^{(2)}(neutron) = -0.013 \pm 0.006$. Numerically our results roughly agree
with those obtained by Balitsky, Braun and Kolesnichenko based on a sum rule
for a simpler current. Our calculations are far more stable as tested within
the sum rule approach but are more sensitive to less well known condensates.


title:
The Infrared Sensitivity of Screening and Damping in a Quark-Gluon
  Plasma

abstract:
  All the next-to-leading order contributions to the quasi-particle dispersion
laws of a quark-gluon plasma which due to infrared singularities are sensitive
to the magnetic-mass scale are calculated using Braaten-Pisarski resummation.
These relative-order-$g\ln(g)$ corrections are shown here to generally
contribute to the dynamical screening of gluonic fields with frequencies below
the plasma frequency as well as to the damping of propagating gluonic and
fermionic quasi-particles. In the limit of vanishing wave-vector the infrared
singularities disappear, but in a way that raises the possibility for formally
higher orders of the Braaten-Pisarski scheme to equally contribute at
next-to-leading order when the wave-vector is of the order of or less than the
magnetic-mass scale. This is argued to be a problem in particular for the
fermionic damping rate.


title: Some Results on the BESS Model at Future Colliders

abstract:
  We present some results on the usefulness of upgraded Tevatron, LHC proton
proton collider and linear e+e- colliders in the TeV range to test the idea of
a strongly interacting sector as responsible for the electroweak symmetry
breaking. The calculations are performed within an effective lagrangian
description, called the BESS model, which provides for a rather general frame
based on the standing point of custodial symmetry and gauge invariance, without
specifying any dynamical scheme.


title: The Gluon Condensate and Running Coupling of QCD

abstract:
  An expression for the photon condensate in quantum electrodynamics is
presented and generalized to deduce a simple relation between the gluon
condensate and the running coupling constant of quantum chromodynamics (QCD).
Ambiguities in defining the condensates are discussed. The values of the gluon
condensate from some Ans\"{a}tze for the running coupling in the literature are
compared with the value determined from QCD sum rules.


title: CP Violation and the Baryonic Asymmetry of the Universe

abstract:
  The physics of electroweak baryogenesis is described with the aim of making
the essentials clear to non-experts. Several models for the source of the
necessary CP violation are discussed: CKM phases as in the minimal standard
model, general two higgs doublet models, the supersymmetric standard model, $Z$
condensates, and the singlet majoron model. In a more technical section, a
strategy is introduced for consistently treating quark dynamics in the
neighborhood of the bubble wall, where both local and non-local interactions
are important. This provides a method for deciding whether gluonic corrections
wash out the elecroweak contribution to the baryonic asymmetry in the minimal
standard model.


title: Diquarks in a chiral soliton field

abstract:
  In the Nambu--Jona-Lasinio model baryons are either considered as
quark-diquark-composites or the soliton configurations of the model are
interpreted as baryons. As a first step towards constructing a hybrid model,
which possesses a dynamical interplay between both pictures, the Bethe-Salpeter
equation for diquarks in the background of a soliton configuration is solved.
The presence of the soliton causes a significant reduction of the resulting
bound state eigenenergy of the diquark. As a consequence a unit baryon number
configuration may be constructed with a mass lower than the energy of the
soliton. An estimate of the influence of the diquark on the meson fields
indicates a small decrease of the extension of the soliton due to diquark
correlations.


title: Radiative Weak Decays of Charm Mesons

abstract:
  We address Standard Model predictions for flavor-changing radiative
transitions of the pseudoscalar charm mesons. Short-distance contributions in
$D$ radiative transitions are contrasted with those in B decays. A full
analysis is presented of the $c\to u+\gamma$ electromagnetic penguin amplitude
with QCD radiative corrections included. Given the importance of long-range
effects for the charm sector, special attention is paid to such contributions
as the vector dominance and pole amplitudes. A number of two-body final states
in exclusive charm radiative decays is considered and the corresponding
branching ratio predictions are given.


title:
CONFRONTING LEFT-RIGHT SYMMETRIC MODELS WITH ELECTROWEAK PRECISION DATA
  AT THE Z PEAK

abstract:
  In view of the recent and future electroweak precision data accumulated at
LEP and SLC, we systematically analyze possible new physics effects that may
occur in the leptonic sector within the context of $SU(2)_R \times SU(2)_L
\times U(1)_{B-L}$ theories. It is shown that nonobservation of
flavour-violating $Z$-boson decays, lepton universality in the decays $Z\to
l\bar{l}$, and universality of lepton asymmetries at the $Z$ peak form a set of
complementary observables, yielding severe constraints on the parameter space
of these theories. Contributions of new-physics effects to $R_b=\Gamma(Z\to
b\bar{b})/\Gamma(Z\to \mbox{hadrons})$ are found to give interesting mass
relations for the flavour-changing Higgs scalars present in these models.


title:
Constraining the Strongly-Coupled Standard Model Including a W'
  Isotriplet

abstract:
  We consider the Strongly-Coupled Standard Model (Abbott-Farhi model)
including an isotriplet of W' vector bosons. First we calculate the corrections
to the low-energy theory, which can be effectively summarized in terms of the
parameters S, T and U. Then we use high- precision electroweak measurements to
constrain the mass and couplings of the W'. The W' couplings are restricted to
be unnaturally small, and we conclude that this model is no longer compelling
as a theory of the electroweak interactions.


title: On Multiple Instanton-antiinstanton Configurations

abstract:
  We show why and how the $I\bar I$ valley trajectory commonly used in the
literature so far is in fact unsatisfactory. A better $I\bar I$ valley is
suggested. We also give analytic expressions for the multiple
instanton-antiinstanton configurations in the pure Yang-Mills theory. These
formulas make it possible to go beyond the dilute gas approximation and
calculate the multi-body interactions among instantons and antiinstantons.


title: On Constrained-Instanton Valleys

abstract:
  We develop a systematic treatment for the quasi-zero modes, which play an
important role in nonabelian gauge theories. It can be used to derive the
analytic forms for the constrained instantons in the \ymh theory. This will
automatically sum up contributions to all orders in $\rho$, the instanton size.
We also give the analytic expressions for the instanton-antiinstanton pair,
with an arbitrary relative phase. We apply the results to the computation for
high energy baryon number violating cross section, as well as to Klinkhamer's
new instanton.


title: FLAVOR-SINGLET g_A FROM LATTICE QCD

abstract:
  We report on a lattice QCD calculation of the flavor-singlet axial coupling
constant $g_A$ of the proton from the axial-vector current. The simulation is
carried out at $\beta = 6$ on a quenched $16^3 \times 24$ lattice. An
extrapolation to the chiral limit shows that the connected insertion (valence
and cloud parts) is $0.62 \pm 0.09$, which is close to $g_A^8$. The
disconnected insertion (vacuum polarization from the sea quark) for the $u$ or
$d$ quark is $- 0.12\pm 0.01 $ and the $s$ quark also contributes $-0.12\pm
0.01$. The total $g_A^1$ is thus $0.25 \pm 0.12$ which is in agreement with
experiments. In addition, we find $g_A^3 = 1.20 \pm 0.11$, $g_A^8 = 0.61 \pm
0.13$ and $F_A/D_A = 0.60 \pm 0.02$, also in agreement with experiments.


title: Chiral Lagrangians and Nambu-Jona-Lasinio like models

abstract:
  We discuss the low-energy analysis of models involving quarks and
four-fermion couplings. The relation with QCD and with other models of mesons
and meson plus quarks at low energies is discussed. A short description of how
the heat-kernel expansion can be used to get regularization independent
information, is given. The anomaly within this class of models and a physical
prescription to obtain the correct flavour anomaly while keeping as much of the
VMD aspects as possible is discussed. The major part is the discussion within
this framework of the order $p^4$ action and of two and some three-point
functions to all orders in momenta and quark masses. Some results on hadronic
matrix elements are given.


title: Pinning down the Glue in the Proton

abstract:
  The latest measurements of $F_2$ at HERA allow for a {\it combination} of
gluon and sea quark distributions at small $x$ that is significantly different
from those of existing parton sets. We perform a new global fit to
deep-inelastic and related data. We find a gluon distribution which is larger
for $x \lapproxeq 0.01$, and smaller for $x \sim 0.1$, and a flatter input sea
quark distribution than those obtained in our most recent global analysis. The
new fit also gives $\alpha_s(M_Z^2) = 0.114$. We study other experimental
information available for the gluon including, in particular, the constraints
coming from fixed-target and collider prompt $\gamma$ production data.


title:
Effect of the Space-like Penguin Diagrams on CP Asymmetries in Exclusive
  B Decays

abstract:
  The space-like penguin contributions were ignored on little ground in many
previous studies of nonleptonic B decays and CP violation. Taking the
penguin-dominated channels $B^{-} _{u}\rightarrow \bar{K}^{0}\pi$ and
$B^{-}_{u}\rightarrow K^{0} K^{-}$ for example, we illustrate the
non-negligible effects of the space-like penguin diagrams on CP asymmetries.
Some quali- tative remarks are given on the gluonic penguin picture and the
direct CP violation in exclusive two-body decays of B mesons.


title: Next-to-leading Order Radiative Corrections to the Decay $b\to ccs$

abstract:
  We calculate the complete ${\cal O}(\alpha_s)$ corrections to the quark decay
$b\to ccs$ taking full account of the quark masses, but neglecting penguin
contributions. For a c to the b quark mass ratio $m_c/m_b= 0.3$ and a strange
quark mass of $0.2\,$GeV, we find that the next-to-leading order (NLO)
corrections increase $\Gamma(b\to ccs)$ by $(32\pm 15)\%$ with respect to the
leading order expression, where the uncertainty is mostly due to scale- and
scheme-dependences. Combining this result with the known NLO and
non-perturbative corrections to other B meson decay channels we obtain an
updated value for the semileptonic branching ratio of B mesons, $B_{SL}$, of
$(12.0\pm 1.4)\% $ using pole quark masses and $(11.2\pm 1.7)\% $ using running
$\overline{\mbox{MS}}$ masses.


title:
Remarks on the Quark-diagram Description of Two-body Nonleptonic B-meson
  Decays

abstract:
  To lowest-order weak interactions in the standard model, we point out that a
complete graph description of two-body mesonic $B$ (or $D$) decays needs ten
topologically different quark diagrams. The two-body baryonic $B$ decays can be
illustrated in terms of five diagrams. We remark a variety of features of the
graph language. Some pure channels of mesonic $B$ decays, which can be used to
test the quark-diagram scheme, are discussed in some detail.


title: Scale Dependence and Small-x Behaviour of Polarized Parton Distributions

abstract:
  We discuss perturbative evolution of the polarized structure function g_1 in
the (x,Q^2) plane, with special regard to the small-x region. We determine g_1
in terms of polarized quark and gluon distributions using coefficient functions
to order alpha_s. At small x g_1 then displays substantial scale dependence,
which necessarily implies a corresponding scale dependence in the large-x
region. This scale dependence has significant consequences for the extraction
of the first moment from the experimental data, reducing its value while
increasing the error. Conversely, the scale dependence may be used to constrain
the size of the polarized gluon distribution.


title: Top quark inclusive differential distributions

abstract:
  The inclusive transverse momentum and rapidity distributions for top quark
production at the Fermilab Tevatron are presented both in order $\alpha_s^3$ in
QCD and using the resummation of the leading soft gluon corrections in all
orders of QCD perturbation theory. The resummed results are uniformly larger
than the $O(\alpha_s^3)$ results for both distributions.


title:
Fermion Number Violation in the Background of a Gauge Field in Minkowski
  Space

abstract:
  Anomalous fermion number violation is studied in the background of a pure
SU(2) gauge field in Minkowski space using the method of N. Christ. It is
demonstrated that the chiral fermion number is violated by at most an integer
amount. Then the method is applied for a spherically symmetric Minkowski space
classical gauge field in the background. These classical gauge fields are
finite energy solutions to pure SU(2) equations of motion with in general
non-integer topological charge. We show that in the classical background which
during a finite time-interval matches such solutions the fermion number
violation is integer and non-zero. In particular, we calculate the violation of
the fermion number in the presence of L\"uscher-Schechter solutions. The
meaning of anomaly equation and applications to QCD and electroweak theory are
briefly discussed. We also comment on the relation of the results of this paper
to the previous work.


title: The LHC Phenomenology of the CP-odd Scalar in Two-Doublet Models

abstract:
  We discuss possible signatures of the $CP$-odd scalar of two-doublet models
at the LHC. We find that the inclusive two-photon decay mode and the decay
sequence $A^0 \rightarrow Zh, h \rightarrow \gamma \gamma$, where $h$ is a
$CP$-even neutral scalar, can give viable signals in fairly large and
complementary regions of parameter space.


title: Upper bounds on supersymmetry breaking from gauge coupling unification

abstract:
  I derive conservative upper bounds on the supersymmetry breaking parameter
$m_{1/2}$ as a function of the strong coupling in the Standard Supersymmetric
Model (SSM) using gauge coupling unification. I find that over more than $99\%$
of the parameter space, $\alpha_3>0.120$ implies that $m_{1/2}$ is below
$10\TeV$ and $\alpha_3>0.129$ implies that $m_{1/2}$ is below $1\TeV$. I
express the variation of these bounds over the SSM parameter space with a
numerical coefficient, $c$. I also find that in the SSM, a reasonable value of
$50\GeV<m_{1/2}<1\TeV$ requires $\alpha_3>0.119$ over the whole parameter
space. These bounds are particularly sensitive to the value of
$\sin^2\theta_W=0.2317\pm0.0005$ used in the calculation. In more realistic
models, heavy thresholds and gravitational effects will modify this result.
Although these effects are theoretically calculable in specific models, more
realistic models contain many unknown parameters in practice. I illustrate this
point with minimal supersymmetric $SU(5)$ where the combined constraints of
gauge coupling unification and proton decay require $\alpha_3>0.119$ for
$m_{1/2}<1\TeV$ and the upper bound on the supersymmetry breaking scale is
greatly relaxed.


title: Hadron Structure and the QCD Phase Transition

abstract:
  Firstly, I give a brief summary of the current understanding of QCD below and
near $T_c$ (the critical temperature of the chiral transition). Some emphases
are put on the qualitative difference between the Yukawa regime ($T \sim 0)$
and the Hagedorn regime ($T \sim T_c$). Secondly, the dynamical phenomena
associated with the chiral transition, in particular, the spectral changes of
hadrons in hot and/or dense medium are reviewed from the point of view of the
QCD spectral sum rules. Confusions on the QCD sum rules at finite
temperature/density are also clarified and remarks on the effective lagrangian
approaches are given. Thirdly, planned experiments to detect the spectral
changes in medium are summarized.


title:
Dependence of $|V_{ub}/V_{cb}|$ on Fermi momentum $p_{_F}$ in ACCMM
  model

abstract:
  The Gaussian width of Fermi momentum, $p_{_F}$, is the most important
parameter of the ACCMM model, and its value is essential in the determination
of $|V_{ub}/V_{cb}|$ because the experimental analysis is allowed only at the
end-point region of inclusive semileptonic $B$-decay spectrum. We extract the
value of $|V_{ub}/V_{cb}|$ as a function of $p_{_F}$. We also calculate the
parameter $p_{_F}$ in the relativistic quark model using the variational
method, and obtain $p_{_F} = 0.54$ GeV which is much larger than the commonly
used value, $\sim 0.3$ GeV, in experimental analyses. When we use $p_{_F} =
0.5$ GeV instead of 0.3 GeV, the value of $|V_{ub}/V_{cb}|$ from ACCMM model is
increased by a factor 1.81, and can give a good agreement with Isgur {\it et
al.} model.


title:
B_c meson production in \gamma\gamma collisions and charm content of the
  photon

abstract:
  Based on photon structure function formalism we have calculated
$B_c(B_c^{*})$ meson production cross section in $\gamma\gamma$ collisions via
partonic subprocess $c\gamma\to B_c(B_c^{*}) b$. It was shown that this
approach gives the same results for $B_c^*(B_c)$ meson cross sections as the
direct leading order QCD calculation of the subprocess $\gamma\gamma\to
B_c(B_c^{*})b\bar c$ at small energy. Howere, opposite to the direct QCD
calculation we have obtained the increase of the $B_c(B_c^{*})$ meson cross
section at large energies. We have found also additional contribution to the
$B_c$ meson production via the nonperturbative fluctuations
$\gamma\leftrightarrow J/\psi$.


title:
Estimates of the higher-order QCD corrections to R(s), R_{\tau} and
  deep-inelasstic scattering sum rules

abstract:
  We present the attempt to study the problem of the estimates of higher-order
perturbative corrections to physical quantities in the Euclidean region. Our
considerations are based on the application of the scheme-invariant methods,
namely the principle of minimal sensitivity and the effective charges approach.
We emphasize, that in order to obtain the concrete results for the physical
quantities in the Minkowskian region the results of application of this
formalism should be supplemented by the explicite calculations of the effects
of the analytical continuation. We present the estimates of the order
$O(\alpha^{4}_{s})$ QCD corrections to the Euclidean quantities: the
$e^+e^-$-annihilation $D$-function and the deep inelastic scattering sum rules,
namely the non-polarized and polarized Bjorken sum rules and to the
Gross--Llewellyn Smith sum rule. The results for the $D$-function are further
applied to estimate the $O(\alpha_s^4)$ QCD corrections to the Minkowskian
quantities $R(s) = \sigma_{tot} (e^{+}e^{-} \to {\rm hadrons}) /
  \sigma (e^{+}e^{-} \to \mu^{+} \mu^{-})$ and $R_{\tau} =
  \Gamma (\tau \to \nu_{\tau} + {\rm hadrons}) /
  \Gamma (\tau \to \nu_{\tau} \overline{\nu}_{e} e)$. The problem of the
fixation of the uncertainties due to the $O(\alpha_s^5)$ corrections to the
considered quantities is also discussed.


title:
Quark fragmentation functions in a diquark model for proton and
  $\Lambda$ hyperon production

abstract:
  A simple quark-diquark model for nucleon and $\Lambda$ structure is used to
calculate leading twist light-cone fragmentation functions for a quark to
inclusively decay into P or $\Lambda$. The parameters of the model are
determined by fitting to the known deep-inelastic structure functions of the
nucleon. When evolved from the initial to the final $Q^2$ scale, the calculated
fragmentation functions are in remarkable agreement (for $z>0.4 $) with those
extracted from partially inclusive $ep$ and $e^+ e^-$ experiments at high
energies. Predictions are made, using no additional parameters, for
longitudinally and transversely polarized quarks to fragment into p or
$\Lambda$.


title:
Novel approach to decays, gluon distributions, and fragmentation
  functions of heavy qurakonia

abstract:
  An effective, low-energy, field theory of s-wave quarkonia, constituent heavy
quarks, and gluons is constructed which is manifestly gauge invariant. The
interaction Lagrangian has the form of a twist expansion, as typically
encountered in hard processes, and involves derivatives of arbitrary order. The
parameters in the interaction are related with the non-relativistic wave
function, and standard results for $Q\bar{Q}$ inclusive decays and radiative
transitions are shown to be easily recovered. The light-cone gluon momentum
distribution at very small $x$ is calculated and shown to be uniquely
determined by the non-relativistic wave function. The distribution has a part
which goes as $x^{-1}logx$, ie. is more singular than the usually assumed $1/x$
behaviour. The fragmentation function for a virtual gluon to inclusively decay
into an $\eta_c$ or $\eta_b$ is also calculated. We find that the emission of
low momentum gluons makes this process quite sensitive to assumptions about the
binding of heavy quarks in quarkonia.


title: ASTROPHYSICAL EVIDENCE ON PHYSICS BEYOND THE STANDARD MODEL

abstract:
  Astrophysics and cosmology can be used to test the standard model of particle
physics under conditions and over distance and time scales not accessible to
laboratory experiments. Most of the astrophysical observations are in good
agreement with the standard model. In particular, primordial nucleosynthesis,
supernova explosions, stellar evolution and cosmic background radiations have
been used to derive strong limits on physics beyond the standard model.
However, the solution of some important astrophysical and cosmological problems
may require new physics beyond the standard model. These include the origin of
the initial conditions, large scale structure formation, the baryon asymmetry
in the observed Universe, the dark matter problem, the solar neutrino problem
and some cosmic ray puzzles. Here I review some important developments relevant
to some of these problems, which took place most recently.


title: Renormalons and the Heavy Quark Effective Theory

abstract:
  We propose a non-perturbative method for defining the higher dimensional
operators which appear in the Heavy Quark Effective Theory (HQET), such that
their matrix elements are free of renormalon singularities, and diverge at most
logarithmically with the ultra-violet cut-off. Matrix elements of these
operators can be computed numerically in lattice simulations of the HQET. We
illustrate our procedures by presenting physical definitions of the binding
energy ($\lb$) and of the kinetic energy (-$\lambda_1/2m_Q$) of the heavy quark
in a hadron. This allows us to define a ``subtracted pole mass", whose inverse
can be used as the expansion parameter in applications of the HQET.


title: The decay $b\to s\gamma$ in the 3-3-1 model

abstract:
  The 3-3-1 model, based on the gauge group $SU(3)_c\times SU(3)_L\times
U(1)_X$, makes a natural prediction of three generations based on anomaly
cancellation. Since this is accomplished by incorporating the third family of
quarks differently from the other two, it leads to potentially large flavor
changing neutral currents. A sensitive place to look for such effects is the
flavor changing $b\to s\gamma$ decay, which has recently been measured at CLEO.
We compute this decay rate in the 3-3-1 model and compare it with that of the
two-Higgs-doublet model, a subset of the full 3-3-1 model. We find that the
additional 3-3-1 physics weakens the bound on the charged Higgs mass from
$M_{H^+}>290$~GeV to $M_{H^+}\agt120$~GeV.


title:
THE HIGH TEMPERATURE DISPERSION EQUATION FOR LONGITUDINAL PLASMA
  OSCILLATIONS IN TAG

abstract:
  The calculations in the temporal axial gauge (TAG) are revised and a new
prescription is introduced to avoid the well-known TAG-singularity. With this
prescription we use the TAG-formalism to calculate the one-loop dispersion
equation for the longitudinal plasma oscillations in the high temperature limit
and find the complete selfconsistency of TAG for pragmatic aims. Our result
reproduces the earlier known dispersion equation obtained in covariant gauges
and this equality explicitly demonstrates the gauge independence of the
dispersion law in the high temperature limit and its reliability.


title:
How To Use SU(3)-Flavor Symmetry to Extract CP Violating Phases and
  Strong Phase Shifts at CLEO

abstract:
  After a short introduction to the SM picture of CP violation, we discuss
recent work on how to use SU(3) flavor symmetry, along with some dynamical
approximations, to extract the CKM weak phases and the strong rescattering
phases from experimental measurements alone. This suprising wealth of
information depends on our two strongest assumptions: SU(3) invariance, and the
relative unimportance of exhange and annihilation diagrams. We discuss soon to
be measured decay rate measurements that will test the validity of these
assumptions.


title: POMERON FLUX RENORMALIZATION IN SOFT AND HARD DIFFRACTION

abstract:
  While the main features of elastic, diffractive and total cross sections are
described well by Regge theory, the measured rise of the proton-(anti)proton
single diffraction dissociation cross section with energy is considerably
smaller than the theoretical prediction based on factorization and a constant
triple-pomeron coupling. The observed energy dependence is obtained by
renormalizing the pomeron flux "carried" by a nucleon to unity. Double
diffraction and double pomeron exchange cross sections are reevaluated and
compared to data, and a new interpretation of hard diffraction results emerges
in which the hard pomeron obeys the momentum sum rule.


title: Recent Results on QCD Corrections to Semileptonic $b$-Decays

abstract:
  We summarize recent results on QCD corrections to various observables in
semileptonic $b$ quark decays. For massless leptons in the final state we
present effects of such corrections on triple differential distribution of
leptons which are important in studies of polarized $b$ quark decays. Analogous
formulas for distributions of neutrinos are applicable in decays of polarized
$c$ quarks. In the case of decays with a $\tau$ lepton in the final state mass
effect of $\tau$ has to be included. In this case we concentrate on corrections
to the total decay width.


title: AXIONS IN ASTROPHYSICS AND COSMOLOGY

abstract:
  If axions exist they are efficiently produced in the hot and dense interior
of stars, providing a novel energy-loss mechanism. In order to avoid a conflict
with the observed properties of stars, one can derive a lower limit on the
Peccei-Quinn scale (an upper limit on the axion mass). In the early universe,
axions are produced by the ``misalignment mechanism'' and the emission from
global strings as well as the relaxation of the string-domain wall system
formed at the QCD phase transition. In order to avoid an ``overclosed
universe'' the Peccei-Quinn scale must obey an upper limit (a lower limit on
the axion mass). The current values of these bounds are reviewed. There remains
a ``window of opportunity'' $10^{-5}\,\eV\lapprox m_a\lapprox 10^{-2}\,\eV$,
with large uncertainties on either side, where axions could still exist.
[Contribution to the XVth Moriond workshop, 21-28 Jan. 1995, Villars-sur-Ollon,
Switzerland.]


title: Weak decays of doubly heavy hadrons

abstract:
  We explore the application and usefulness of the heavy quark symmetry to
describe the weak decays of hadrons (mesons and baryons) containing two heavy
quarks. Firstly, we address the internal dynamics of a heavy-heavy bound system
with the help of estimates based on potential models, showing an approximate
spin symmetry in the preasymptotic quark mass region including charmonium,
bottonium and $B_c$ meson states. However, no asymptotic spin symmetry should
hold in the infinite quark mass limit in contrast to singly heavy hadrons.
Predictions on semileptonic and two-body nonleptonic decays of $B_c$ mesons are
shown. Furthermore, the stemming flavor and spin symmetries from the
interaction between the heavy and light components in hadrons (combining in a
$\lq\lq$superflavor" symmetry) permit their classification in $meson$-type
supermultiplets containing singly heavy mesons together with doubly heavy
baryons, and $baryon$-type supermultiplets containing singly heavy baryons
together with some exotic doubly heavy multiquark states (diquonia). Exploiting
their well-defined transformation properties under the superflavor symmetry
group, we get predictions on the widths for some semileptonic and two-body
nonleptonic decays of baryons containing both $b$ and $c$ quarks.


title:
Electromagnetic form factors of the $\rho$ meson in a light-front
  constituent quark model

abstract:
  The electromagnetic form factors of the $\rho$ meson are evaluated adopting a
relativistic constituent quark model based on the light-front formalism, and
using a meson wave function with the high-momentum tail generated by the
one-gluon-exchange interaction. The breakdown of the rotational covariance for
the one-body component of the current operator is investigated and the
sensitivity of the ratio of the $\rho$-meson form factors to the pion (charge)
form factor to the spin-dependent component of the effective $q \bar{q}$
interaction is illustrated.


title: Gauge Invariant Quark Propagator in the Instanton Background

abstract:
  After a general discussion on the choice of gauge, we compare the quark
propagator in the background of one instanton in regular and singular gauge
with a gauge invariant propagator obtained by inserting a path-ordered gluon
exponential. Using a gauge motivated by this analysis, we were able to obtain a
finite result for the quark condensate without introducing an infrared cutoff
nor invoking some instanton model.


title: Renormalization of $K^+ K^- \to \pi^0\pi^+\pi^-$

abstract:
  We derive the vertices of five-meson and seven-meson anomaly processes from
the four dimensional expansion form of Wess-Zumino term. Using these vertices
we calculate the amplitude, both the finite part and divergent part, of {$K^+
K^- \rightarrow \pi^0 \pi^+ \pi^-$} to one loop and renormalize the lagrangian.
The divergent part agrees with the result derived from path integral approach.
Contribution from counter terms is estimated by using the vector meson
dominance model. Test of the vertex in the $t$-channel of $K^-
P\rightarrow\Sigma^0\pi^0\pi^+\pi^-$ near the threshold is discussed. We find
that the amplitudes arising from chiral loop and counter terms are of opposite
sign and the counter term amplitude is about twice the loop amplitude.


title: The $B_K$ Parameter in the $1/N_c$ Expansion

abstract:
  We calculate the $B_K$ parameter within the framework of the $1/N_c$
expansion. We essentially use the technique presented by Bardeen, Buras and
G\'erard but calculate an off-shell Green function in order to disentangle
different contributions. We study this Green function in pure Chiral
Perturbation Theory (CHPT) first and afterwards in the $1/N_c$ expansion in the
presence of an explicit cut-off to determine $B_K$ and the counterterms
appearing in CHPT. The high energy part is done using the renormalization
group. For the low-energy contributions we use both CHPT and an Extended
Nambu--Jona-Lasinio model. This model has the right properties to match with
the high energy QCD behaviour. We then study explicit chiral symmetry breaking
effects by calculating with both massless and degenerate quarks together with
the real case. A detailed analysis and comparison with the results found within
other approaches is done. Consequences for present lattice calculations of this
parameter are then obtained. As final result we get $0.60 < \hat B_K < 0.80$.
If $m_s=m_d=0$ we get $0.25 < \hat B^\chi_K < 0.55$.


title:
Gauge Dependence of Four-Fermion QED Green Function and Atom-Like Bound
  State Calculations

abstract:
  We derive a relation between four-fermion QED Green functions of different
covariant gauges which defines the gauge dependence completely. We use the
derived gauge dependence to check the gauge invariance of atom-like bound state
calculations. We find that the existing QED procedure does not provide gauge
invariant binding energies. A way to a corrected gauge invariant procedure is
pointed out.


title:
Minimization of the scalar Higgs potential in the Finite Supersymmetric
  Grand Unified Theory

abstract:
  Exact mathematical solution of the minimization conditions of scalar the
Higgs potential of the Finite Supersymmetric Grand Unification Theory is
proposed and extremal field configurations are found. Types of extrema are
investigated and masses of the new Higgs particles arisen after electroweak
symmetry breaking are derived analytically. The conditions for existing of
physically acceptable minimum are given. As it appears, this minimum is simple
generalization of the analogous solution in the Minimal Supersymmetric Standard
Model. Phenomenological consequences are discussed briefly.


title: Chiral Perturbation Theory

abstract:
  An introduction to the basic ideas and methods of Chiral Perturbation Theory
is presented. Several phenomenological applications of the effective Lagrangian
technique to strong, electromagnetic and weak interactions are discussed.


title: JET ANALYSIS BY NEURAL NETWORKS IN HIGH ENERGY HADRON-HADRON COLLISIONS

abstract:
  We study the possibility to employ neural networks to simulate jet clustering
procedures in high energy hadron-hadron collisions. We concentrate our analysis
on the Fermilab Tevatron energy and on the $k_\bot$ algorithm. We consider both
supervised multilayer feed-forward network trained by the backpropagation
algorithm and unsupervised learning, where the neural network autonomously
organizes the events in clusters.


title:
A Study of the A dependence of deep-inelastic scattering of leptons and
  its implications for understanding of the EMC effect

abstract:
  It is suggested to determine the $A$ dependence of distortions of the nucleon
structure function $F_2(x)$ by summing the distortions over an interval ($x_1,
x_2$). It was found from the analysis of data on deep--inelastic scattering of
muons and electrons from nuclei that the $A$ dependence of distortion
magnitudes obtained in each of three regions under study, namely shadowing,
antishadowing and the EMC effect region, follow the same functional form, being
different in the normalizing factor only. All the available data give evidence
for the saturation of the distortion magnitude with rising $A$.


title: TWO-PION EXCHANGE NUCLEAR POTENTIAL - CHIRAL CANCELLATIONS

abstract:
  We show that chiral symmetry is responsible for large cancellations in the
two-pion exchange nucleon-nucleon interaction, which are similar to those
occuring in free pion-nucleon scattering.


title:
Numerical investigations of baryon non-conserving processes in the
  electroweak theory

abstract:
  We illustrate the use of computational methods for the study of baryon
non-conservation in high energy electroweak processes.