title:
Chiral Perturbation Theory for $\tau \to \rho \pi\nu_\tau$, $\tau \to
  K^* \pi \nu_\tau$, and $\tau \to \omega \pi \nu_\tau$

abstract:
  We use heavy vector meson $SU(2)_L \times SU(2)_R$ chiral perturbation theory
to predict differential decay distributions for $\tau \rightarrow \rho \pi
\nu_\tau$ and $\tau \rightarrow K^* \pi \nu_\tau$ in the kinematic region where
$p_V \cdot p_\pi/m_V$ (here $V = \rho$ or $K^*$) is much smaller than the
chiral symmetry breaking scale. Using the large number of colors limit we also
predict the rate for $\tau \rightarrow \omega \pi \nu_\tau$ in this region (now
$V = \omega$). Comparing our prediction with experimental data, we determine
one of the coupling constants in the heavy vector meson chiral Lagrangian.


title: Cherenkov radiation by massless neutrinos

abstract:
  Due to their weak interactions, neutrinos can polarize a medium and acquire
an induced charge. We consider the Cherenkov radiation emitted by neutrinos due
to their effective electromagnetic interactions as they pass through a
polarizable medium. The effect exists even for massless, chiral neutrinos,
where no physics beyond the standard model needs to be assumed.


title: Weak magnetic dipole moments in two-Higgs-doublet models

abstract:
  We investigate the effects of the new scalars in a two-Higgs-doublet model on
the weak magnetic dipole moments of the fermions at the $Z$ peak.
Proportionality of the Yukawa couplings to the fermion masses, and to
$\tan{\beta}$, makes such effects more important for the third family, and
potentially relevant. For the $\tau$ lepton, the new diagrams are suppressed by
$v_\tau = 2 \sin^2 \theta_W - 1/2$, or by powers of $m_\tau/M_Z$, but may still
be comparable to the SM electroweak contributions. In contrast, we find that
the new contributions for the bottom quark may be much larger than the SM
electroweak contributions. These new effects may even compete with the gluonic
contribution, if the extra scalars are light and $\tan \beta$ is large. We also
comment on the problem of the gauge dependence of the vertex, arising when the
$Z$ is off mass shell. We compute the contributions from the new scalars to the
magnetic dipole moments for top-quark production at the NLC, and for bottom and
$ \tau $ production at LEP2. In the case of the top, we find that the SM
electroweak and gluonic contributions to the $Z t {\bar t}$ vertex are
comparable. The new contributions may be of the same order of magnitude as the
standard-model ones, but not much larger.


title:
Large Gauge Transformations and Magnetic Vortices in Axial Gauge
  QCD_{3+1}

abstract:
  It is shown that in the modified axial gauge version of canonically quantized
QCD$_{3+1}$ on a torus only nongeneric gauge field configurations allow for
large gauge transformations. For the other configurations, the gauge is fixed
completely. Such configurations carry nonzero total magnetic abelian fluxes,
correspond to magnetic vortices parallel to the coordinate axes and are
incorporated using both singular gauge fields and a change of boundary
conditions.


title: Thermal Fermionic Dispersion Relations in a Magnetic Field

abstract:
  The thermal self-energy of an electron in a static uniform magnetic field $B$
is calculated to first order in the fine structure constant $\alpha $ and to
all orders in $eB$. We use two methods, one based on the Furry picture and
another based on Schwinger's proper-time method. As external states we consider
relativistic Landau levels with special emphasis on the lowest Landau level. In
the high-temperature limit we derive self-consistent dispersion relations for
particle and hole excitations, showing the chiral asymmetry caused by the
external field. For weak fields, earlier results on the ground- state energy
and the anomalous magnetic moment are discussed and compared with the present
analysis. In the strong-field limit the appearance of a field-independent
imaginary part of the self-energy, related to Landau damping in the
$e^{+}e^{-}$ plasma, is pointed out.


title: Hybrids: Dynamics and Disguises

abstract:
  We introduce general selection rules arizing from flux-tube dynamics with
non-relativistic and adiabatic quark motion, without employing model-dependent
assumptions. Specifically, we indicate under which circumstances hybrids with
an arbitrary degree of flux-tube excitation can disguise themselves by not
decaying to S--wave states.


title: QCD Corrections for the $K^0-\bar K^0$ and $B^0 - \bar B^0$ System

abstract:
  The QCD corrections for the box diagrams are revisited for the case of a
heavy top quark with $\mt = 174 \GeV$. We resolve first a longstanding
discrepancy between two methods of calculation by showing that they give the
same results when the threshold factors are treated correctly. Using this
observation we refine our earlier results and derive formulae valid for the
$K$- and $B$-meson systems. Our formulae are given in terms of integrals to be
evaluated numerically, as well as approximate analytical formulae. These
calculations include the evolution above $\MW$ which has been neglected by
other authors.


title: Stability of the B=2 hedgehog in the Skyrme model

abstract:
  We study the unstable modes of the baryon number two hedgehog of the Skyrme
model on a three dimensional spatial lattice. An expansion of the Skyrme
Lagrangian around the hedgehog configuration provides the equations of motion
for the fluctuation fields solvable numerically via a relaxation method. We
find the negative energy modes and, by evolving the excited hedgehog in time, a
breakup into two separated solitonic configurations is obtained. Different
paths of descent for the receding Skyrmions are presented and the possibility
of determining the metric structure of the collective-coordinate manifold is
discussed.


title: Colorless and colored gluon-clusters in nucleon?

abstract:
  It is suggested that virtual gluon-clusters exist in nucleon, and that such
colorless and colored objects manifest themselves in the small $x_B$ region of
inelastic lepton-nucleon scattering processes. The relationship between the
space-time properties of such clusters and the striking features observed in
these scattering processes is discussed. A phase-space model is used to show
how quantitative results can be obtained in such an approach. The results of
this model-calculation are in reasonable agreement with the existing data.
Further experiments are suggested.


title: Atmospheric neutrino flux above 1 GeV

abstract:
  In this paper we extend an earlier calculation of the flux of atmospheric
neutrinos to higher energy. The earlier calculation of the neutrino flux below
3 GeV has been used for calculation of the rate of contained neutrino
interactions in deep underground detectors. The fluxes are needed up to
neutrino energies of 10 TeV to calculate the expected rate of neutrino-induced
muons passing into and through large, deep detectors. We compare our results
with several other calculations, and we evaluate the uncertainty in the rate of
neutrino-induced muons due to uncertainties in the neutrino flux.


title: Detecting a Light Stop from Top Decays at the Tevatron

abstract:
  We study the possibility of discovering or excluding a light top squark
(stop) based on top quark decays in the t-tbar events produced at the Fermilab
Tevatron. In particular, we consider the Minimal Supersymmetric Standard Model
with the sparticle spectrum m_{chi^+_1}+m_b, M_W+m_{chi^0_1}+m_b > m_{stop} >
m_{chi^0_1}+m_c, where chi^0_1 is the lightest neutralino and chi^+_1 is the
lightest chargino, so that t -> stop chi^0_1 and stop -> c chi^0_1. All other
sparticle masses are assumed to be heavier than m_t. Such a spectrum seeks to
explain the experimental values of alpha_s(M_Z^2), R_b and A_{LR} obtained from
LEP/SLC data. We find that the prospect to observe a light stop via this
channel at the Tevatron is very promising.


title: Testing superstring-inspired E(6) models at linear e+e- colliders

abstract:
  It is shown that in a large class of E(6) models, either an e+e- collider
operating at $\rs \geq 1.5$ TeV must find a signal for the production of exotic
leptons, or a collider operating at $\rs \geq 300$ GeV must find at least one
light neutral Higgs boson with a large invisible branching ratio. The region of
parameter space where neither of these signals is visible can be excluded
because here the lightest neutral exotic lepton, which is absolutely stable,
would overclose the Universe.


title:
Hydrodynamical analysis of single inclusive spectra and Bose-Einstein
  correlations for $Pb+Pb$ at 160 AGeV

abstract:
  We present the first analysis of preliminary data for $Pb+Pb$ at 160 $AGeV$
using 3+1-dimensional relativistic hydrodynamics. We find excellent agreement
with the rapidity spectra of negative hadrons and the correlation measurements.
The data indicates a large amount of stopping; $65\%$ of the invariant energy
of the collision is thermalized and $73\%$ of the baryons are contained in the
central fireball. Within our model this implies that a quark-gluon-plasma of
lifetime 3.4 $fm/c$ was formed.


title:
A Nonperturbative Calculation of Basic Chiral QCD Parameters within
  Dynamical Equations Approach to QCD at Low Energies

abstract:
  Basic chiral QCD parameters (the pion decay constant, the quark and gluon
condensates, the dynamically generated quark mass, etc) as well as the vacuum
energy density have been calculated from first principles within a recently
proposed dynamical equations approach to QCD at low energies. The zero modes
enhancement (ZME) model of quark confinement and dynamical chiral symmetry
breaking (DCSB) based on the solution to the Schwinger-Dyson (SD) equation for
the quark propagator in the infrared (IR) domain was used for this purpose.
There are only two independent quantities by means of which calculations should
be done within our approach. Our unique input data was chosen to be the pion
decay constant in the chiral limit given by the chiral perturbation theory at
the hadronic level (CHPTh). Phenomenological estimates of these quantities, as
well as the vacuum energy density, are in good agreement with our numerical
results. The nonperturbative vacuum structure which emerges from the ZME model,
appears to be well suited to describe quark confinement, DCSB,
current-effective (dynamical)-constituent, as well as constituent-valence quark
transformations, the Okubo-Zweig-Iizuka (OZI) rule, dimensional transmutation,
etc. The importance of the instanton-type fluctuations in the true QCD vacuum
for the ZME model is also emphasized. This allows to predict new, more
realistic values for the vacuum energy density (apart from the sign, by
definition, the bag constant) and the gluon condensate.


title: Amplitude relations for $B$ decays involving $\eta$ and $\eta'$

abstract:
  A class of amplitude relations for decays of $B$ mesons is discussed.
Processes involving $\eta$ and $\eta'$ in the final state are shown to provide
useful information about weak phases in some cases even in the presence of
octet-singlet mixing in these states. Some of the relations are unaffected by
first-order SU(3) breaking.


title: Solar neutrinos (almost) without standard solar models

abstract:
  We extract information on the fluxes of Be and CNO neutrinos directly from
solar neutrino experiments, with minimal assumptions about solar models. Next
we compare these results with solar models, both standard and non standard
ones. Finally we discuss the expectations for Borexino, both in the case of
standard and non standard neutrinos.


title: Goldstone Supermultiplet as the Messenger of Supersymmetry Breaking

abstract:
  We consider supersymmetric models in which a (pseudo) Goldstone
supermultiplet plays the role of the messenger of supersymmetry breaking. Such
models lead to a highly predictive form of flavor and CP conserving soft terms,
particularly the soft scalar masses and trilinear couplings vanish at the scale
where the (approximate) global symmetry is spontaneously broken. We discuss
also the possibility for realizing this scheme in supergravity models derived
from string theories.


title: The W-Boson Mass and Precision Tests of the Standard Model

abstract:
  We have examined the electroweak radiative corrections in the LEP precision
data in view of the new measurements of $M_W$ and $m_t$ as well as the recent
progress in the higher order radiative corrections. From the minimal
$\chi^2$-fit to the experimental Z-decay parameters (with the aid of a modified
ZFITTER program), we predict that $M_W=80.29(4)(2)$ GeV where the first error
is due to the uncertainty in the fitted $m_t$ for a fixed $m_H$ and the second
error comes from the $m_H$ in the range of $60-1000$ GeV, which is to be
compared with the current world average $M_W=80.23(18)$ GeV. The current world
average value of $M_W$ and the 1994 LEP data definitely favor nonvanishing
electroweak radiative corrections and are consistent with a heavy $m_t$ as
measured by the recent CDF report but with a heavy Higgs scalar of about 400
GeV within the context of the minimal standard model. The sensitivity of and
the errors in the best fit solutions due to the uncertainties in the gluonic
coupling $\alpha_s(M_Z)$ and $\alpha (M_Z)$ are also studied carefully. In
addition we discuss how the future precision measurements of $M_W$ can provide
a decisive test for the standard model with radiative corrections and give a
profound implication for the measurement of t-quark and Higgs masses.


title: QCD Analysis of Hadronic $\tau$ Decays Revisited

abstract:
  The calculation of perturbative corrections to the spectral moments
observable in hadronic $\tau$ decays is reconsidered. The exact
order-$\alpha_s^3$ results and the resummation procedure of Le~Diberder and
Pich are compared with a partial resummation of the perturbative series based
on the analysis of so-called renormalon chains. The perturbative analysis is
complemented by a model-independent description of power corrections. For the
contributions of dimension four and six in the OPE, it is demonstrated how
infrared renormalon ambiguities in the definition of perturbation theory can be
absorbed by a redefinition of nonperturbative parameters. We find that previous
determinations of QCD parameters from a measurement of spectral moments in
$\tau$ decays have underestimated the theoretical uncertainties. Given the
present understanding of the asymptotic behaviour of perturbation theory, the
running coupling constant can be measured at best with a theoretical
uncertainty $\delta\alpha_s(m_\tau^2)\simeq 0.05$, and the gluon condensate
with an uncertainty of order its magnitude. Two weighted integrals of the
hadronic spectral function are constructed, which can be used to test the
absence of dimension-two operators and to measure directly the gluon
condensate.


title: Chiral Lagrangian for Baryons in the $1/N_c$ Expansion

abstract:
  A $1/\N$ expansion of the chiral Lagrangian for baryons is formulated and
used to study the low-energy dynamics of baryons interacting with the pion
nonet $\pi$, $K$, $\eta$ and $\eta^\prime$ in a combined expansion in chiral
symmetry breaking and $1/\N$. Strong $CP$-violation is included. The chiral
Lagrangian correctly implements nonet symmetry and contracted spin-flavor
symmetry for baryons in the large $\N$ limit. The implications of nonet
symmetry for low-energy baryon-pion interactions are described in detail. The
procedure for calculating non-analytic pion-loop corrections to baryon
amplitudes in the $1/\N$ expansion for finite $\N$ is explained. Flavor-$\bf
27$ baryon mass splittings are calculated at leading order in chiral
perturbation theory as an example.


title: Gauge-Yukawa Unification

abstract:
  Gauge-Yukawa Unification (GYU) yields a functional relation among the gauge
and Yukawa couplings, and it may follow from the usual Grand Unification if it
is supplemented with some additional principles. Postulating the principles of
finiteness and reduction of couplings, we have achieved Gauge-Yukawa
Unification in various supersymmetric unified models leading, among other
things, to interesting predictions on the top quark mass.


title: Gauge Vector Masses from Flat Connections?

abstract:
  We suggest that four dimensional massive gauge vectors could be described by
coupling ordinary Yang-Mills theory to a topological gauge theory. For this the
coupling should excite a nontrivial degree of freedom from the topological
theory, corresponding to the longitudinal polarization of a massive gauge
vector. If the coupling can be selected so that further degrees of freedom are
not excited, one may entirely avoid particles such as the Higgs. Here we
discuss a simple example of this idea, obtained by coupling standard Yang-Mills
theory to the topological gauge theory of flat connections. We propose that our
example might describe a renormalizable theory of massive gauge vectors with no
additional physical degrees of freedom.


title: Inclusive $S-$wave charmonium productions in $B$ decays

abstract:
  The inclusive $S-$wave charmonium production rates in $B$ decays are
considered using the Bodwin-Braaten-Lepage (BBL) approach, including the
relativistic corrections and the color-octet mechanism suggested as a possible
solution to the $\psi^{'}$ puzzle at the Tevatron. We first consider
relativistic and radiative corrections to $J/\psi \rightarrow e^{+} e^{-}$ and
$J/\psi \rightarrow$ Light Hadrons (LH), in order to determine two
nonperturbative parameters, $\langle J/\psi | O_{1} (^{3}S_{1}) | J/\psi
\rangle$, $\langle J/\psi | P_{1} (^{3}S_{1}) | J/\psi \rangle$, in the
factorization formulae for these decays. Using these two matrix elements and
including the color-octet $c\bar{c}(^{3}S_{1})$ state contribution, we get a
moderate increase in the decay rates for $B$ decays into $J/\psi ~({\rm
or}~\psi^{'}) ~+ X$. Our results, $B(B \rightarrow J/\psi~({\rm or}~\psi^{'}) +
X) = 0.58~(0.23) \%$ for $M_{b} = 5.3$ GeV, get closer to the recent CLEO data.
As a byproduct, we prefer a larger decay rate for $\eta_{c} \rightarrow$ LH
compared to the present data.


title: QCD from the Lattice

abstract:
  The lattice gauge theory technique for non-perturbative calculations in QCD
is reviewed. The extraction of the continuum limit of lattice results is
discussed with particular examples appropriate to hadron spectroscopy (the
light hadrons and the glueballs). The determination of the strong coupling
constant is presented. The lattice approach to the evaluation of hadronic
matrix elements appropriate to weak decays is described.


title: Thermal Inflation and the Moduli Problem

abstract:
  In supersymmetric theories a field can develop a vacuum expectation value $M
\gg 10^3\,{\rm GeV}$, even though its mass $m$ is of order $10^2$ to
$10^3\,{\rm GeV}$. The finite temperature in the early Universe can hold such a
field at zero, corresponding to a false vacuum with energy density $ V_0 \sim
m^2 M^2 $. When the temperature falls below $V_0^{1/4}$, the thermal energy
density becomes negligible and an era of thermal inflation begins. It ends when
the field rolls away from zero at a temperature of order $m$, corresponding to
of order 10 $e$-folds of inflation which does not affect the density
perturbation generated during ordinary inflation. Thermal inflation can solve
the Polonyi/moduli problem if $M$ is within one or two orders of magnitude of
$10^{12}\,{\rm GeV}$.


title:
Chiral perturbation theory vs. vector meson dominance in the decays
  $\phi \to \rho \gamma \gamma$ and $\phi \to \omega \gamma \gamma$

abstract:
  It is pointed out that the radiative decays of a $\phi$ meson, $\phirho$ and
$\phiom$, receive dominant contributions from the pseudoscalar ($P = \eta,
\eta^{'}$) exchanges. Using the vector meson dominance model, we find that $B
(\phirho) \approx 1.3 \times 10^{-4}$ and $B (\phiom) \approx 1.5 \times
10^{-5}$, which are mainly from the $\eta^{'}$ pole. Thus, these decays are
well within the reach of the $\phi$ factory. Our estimates are a few orders of
magnitude larger than the chiral loop contributions in the heavy vector meson
chiral lagrangian, which is about ( a few ) $\times 10^{-9}$.


title:
Relativistic Kinetic Equations for Electromagnetic, Scalar and
  Pseudoscalar Interactions

abstract:
  We derive the kinetic equations for both the covariant and equal-time Wigner
functions of Dirac particles with electromagnetic, scalar and pseudoscalar
interactions. We emphasize the constraint equations for the spinor components
in the equal-time formulation.


title:
Running coupling at small momenta, renormalization schemes and
  renormalons

abstract:
  We suggest a method of summing the perturbation theory (PT) asymptotic series
related to infrared (IR) renormalons in QCD by using special renormalization
schemes in which the running coupling can be integrated over the region of
small momenta. For the method to work, one should consider higher order PT
corrections to the standard bubble-chain diagrams. High-order corrections allow
one to choose a scheme in which the coupling evolution can smoothly be
extrapolated to small momenta. In such schemes the sum of an (extended)
IR-renormalon asymptotic series is defined as an integral of the running
coupling over the IR region. We give explicit examples of renormalization
schemes in QCD which can be used for summing IR-renormalon asymptotic series
according to our definition.


title:
Heavy Quark Fragmentation Functions for D-wave Quarkonium and Charmed
  Beauty Mesons

abstract:
  At the large transverse momentum region, the production of heavy-heavy
bound-states such as charmonium, bottomonium, and $\bar bc$ mesons in high
energy $e^+e^-$ and hadronic collisions is dominated by parton fragmentation.
We calculate the heavy quark fragmentation functions into the D-wave quarkonium
and $\bar bc$ mesons to leading order in the strong coupling constant and in
the non-relativistic expansion. In the $\bar b c$ meson case, one set of its
D-wave states is expected to lie below the open flavor threshold. The total
fragmentation probability for a $\bar b$ antiquark to split into the D-wave
$\bar b c$ mesons is about $2 \times 10^{-5}$, which implies that only 2\% of
the total pseudo-scalar ground state $B_c$ comes from the cascades of these
orbitally excited states.


title:
Using Rapidity Gaps to Distinguish Between Higgs Production by W and
  Gluon Fusion

abstract:
  The possibility of distinguishing between two higgs production mechanisms, W
fusion and gluon fusion, is investigated using the Monte Carlo event generator
PYTHIA. It is shown that, considering the designed CM energy and luminosity for
the LHC, it is not possible to distinguish between the two higgs production
processes as, for a given integrated luminosity, they lead to the same number
of events containing a rapidity gap.


title: Anomalous $Z'$ effects in the WW channel at NLC

abstract:
  We consider the virtual signals of a $Z'$ of very general type in the process
$e^+e^-\to W^+W^-$ at a future linear collider (NLC). We show that possible
deviations from the SM predictions in this channel are related to similar
deviations in the purely leptonic one in a way that is only characteristic of
this $Z'$ model, and not in general of possible competitor models with
anomalous gauge couplings.


title: The paradox of axions surviving primordial magnetic fields

abstract:
  In the presence of primordial magnetic fields the oscillating cosmic axion
field drives an oscillating electric field. The ensuing dissipation of axions
is found to be inversely proportional to the conductivity of the primordial
plasma. This counterintuitive result is essentially equivalent to ``Zeno's
paradox'' or the ``watched-pot effect'' of quantum mechanics. It implies that
the standard predictions of the cosmic axion density remain unaltered even if
primordial magnetic fields are strong.


title:
$B^*B\pi(\gamma)$ couplings and $D^*\rar D\pi(\gamma) $-decays within a
  $1/M$-expansion in $full$ QCD

abstract:
  To leading order in $\alpha_s$, we evaluate the leading and non-leading
$1/M_b$ corrections to the $B^*B\pi$ and $B^*B\gamma$ couplings using QCD
spectral moment sum rules in the full theory. We find that, for large $M_b$ and
contrary to the heavy-to-light $B\rar \pi(\rho) l\bar \nu$ form factors, which
are dominated by the $soft$ light quark vacuum condensate, these couplings are
governed by the $hard$ perturbative graph, like other heavy-to-heavy
transitions. We also find that for the $B^{*}\rar B\gamma$, the $1/M_b$
correction is mainly due to the perturbative and light quark condensate
contributions originating from the graphs involving the heavy quark part of the
electromagnetic current, which are essential for explaining the large charge
dependence in the observed $D^{*-}\rar D^-\gamma$ and $D^{*0}\rar D^0\gamma$
decays. Our $best$ numerical predictions {\it without any free parameters} for
the $B^*$-meson are: $g_{B^{*-}B^0\pi^-}\simeq 14\pm 4$, $\Gamma_{B^{*-}\rar
B^-\gamma}\simeq (0.10\pm 0.03)$ keV and the large charge dependence of the
ratio: ${\Gamma_{B^{*-}\rar B^- \gamma}}/ {\Gamma_{B^{*0}\rar B^0
\gamma}}\simeq 2.5~$. For the $D^*$-meson, we find: $\Gamma_{D^{*-}\rar
D^0\pi^-}\simeq 1.54\Gamma_{D^{*0}\rar D^0\pi^0} \simeq (8\pm 5)$ keV,
$\Gamma_{D^{*-}\rar D^-\gamma}\simeq (0.09^{+0.40}_{-0.07} )$ keV and
$\Gamma_{D^{*0}\rar D^0\gamma}\simeq (3.7\pm 1.2)$ keV, where the branching
ratios agree within the errors with the present data, while the total widths
$\Gamma_{D^{*0}\rar all} \simeq (11\pm 4)$ keV and $\Gamma_{D^{*-}\rar
all}\simeq (12\pm 7)$ keV are much smaller than the present experimental upper
limits.


title: Squeezed Neutrino Oscillations in Quantum Field Theory

abstract:
  By resorting to recent results on fermion mixing which show that the Fock
space of definite flavor states is unitarily inequivalent to the Fock space of
definite mass states, we discuss the phenomenological implications on the
neutrino oscillation formula. For finite momentum the oscillation amplitude is
depressed, or "squeezed", by a momentum dependent factor. In the relativistic
limit the conventional oscillation formula is recovered.


title: Quark--Antiquark Bethe--Salpeter Equation in QCD

abstract:
  We review our recent results \cite{bsult} on the derivation of a B-S equation
in QCD in a Wilson loop context. We work in a second order formalism, use the
Feynman--Schwinger path integral representation for a quark in external field
and obtain a similar expression for a quark--antiquark amplitude in which the
gauge fields appears only through the Wilson loop integral $W$. A $ q \bar{q}$
B-S equation is obtained starting from this expression under the assumption,
already used in the derivation of heavy quark potential, that $i \ln W$ can be
expressed as the sum of a perturbative contribution and an area term. The
intrinsically nonperturbative derivation method is first discussed on the
simpler case of two spinless particles interacting through a scalar field. The
$q \bar{q}$ semirelativistic potential is reobtained in the large quark mass
limit.


title: Constraints on supersymmetry from FCNC and CP violation

abstract:
  We consider FCNC and CP violating processes mediated by gluino exchange in
generalized supersymmetric theories. We present the constraints on flavour (F)
changing squark mass terms at the electroweak energy scale, focusing our
analysis on $\Delta F = 2$ transitions. Results are also given for $\Delta F =
1$ CP conserving processes both in the hadronic and leptonic sectors, while we
limit ourselves to some remarks on the relevance of box diagrams in the
evaluation of $\epsilon^{\prime}/\epsilon$.


title: Vanishing Str M^2 in the presence of anomalous U_A(1)

abstract:
  We show that the presence of an anomalous $\rm U_A(1)$ factor in the gauge
group of string-derived models may have the new and important phenomenological
consequence of allowing the vanishing of ${\rm Str}\,{\cal M}^2$ in the
``shifted" vacuum, that results in the process of cancelling the anomalous $\rm
U_A(1)$. The feasibility of this effect seems to be enhanced by a vanishing
vacuum energy, and by a ``small" value of ${\rm Str}\,{\cal M}^2$ in the
original vacuum. In the class of free-fermionic models with vanishing vacuum
energy that we focus on, a necessary condition for this mechanism to be
effective is that ${\rm Str}\,{\cal M}^2>0$ in the original vacuum. A vanishing
${\rm Str}\,{\cal M}^2$ ameliorates the cosmological constant problem and is a
necessary element in the stability of the no-scale mechanism.


title: The Equivalence Theorem and infrared divergences

abstract:
  We look at the Equivalence Theorem as a statement about the absence of
polynomial infrared divergences when $m_W \rightarrow 0$. We prove their
absence in a truncated toy model and conjecture that, if they exist at all,
they are due to couplings between light particles.


title: Application of HQET to $B\to K^{(*)}$ Transitions

abstract:
  We examine the measured rates for the decays $D\to K^{(*)}\ell\nu$, $B\to
K^{(*)}\psi^{(\prime)}$ and $B\to K^*\gamma$ in a number of scenarios, in the
framework of the heavy quark effective theory. We attempt to find a scenario in
which all of these decays are described by a single set of form factors. Once
such a scenario is found, we make predictions for the rare decays $B\to
K^{(*)}\ell^+\ell^-$. While we find that many scenarios can provide adequate
descriptions of all the data, somewhat surprisingly, we observe that two
popular choices of form factors, namely monopolar forms and exponential forms,
exhibit some shortcomings, especially when confronted with polarization
observables. We predict $Br(\bar B^0\to \bar K^0\mu^+\mu^-)= 6.4\pm 1.0\times
10^{-7}$ and $Br(\bar B^0\to \bar K^{*0}\mu^+\mu^-)= 3.8\pm 1.3\times 10^{-6}$.
We also make predictions for polarization observables in these decays.


title:
Phenomenology of Minimal SU(5) Unification with Dynamical Supersymmetry
  Breaking

abstract:
  We consider the constraints from proton decay and $b$-$\tau$ unification in
the minimal supersymmetric SU(5) grand unified theory with a `visible'
dynamical supersymmetry breaking sector. We show how the presence of
vector-like messenger fields and the constrained superparticle mass spectrum
affect the phenomenology of the model. We include the messenger fields in our
renormalization group analysis between the messenger scale ($\sim 100$ TeV) and
the GUT scale. We show that the simplest model of this type, a minimal SU(5)
GUT with an additional {\bf 5}+\bfbar{5} of messenger fields is excluded by the
constraints from proton decay and $b$-$\tau$ unification.


title: Dynamical Relaxation of the Supersymmetric CP Violating Phases

abstract:
  A supersymmetric generalization of the Peccei-Quinn mechanism is proposed in
which two U(1) CP violating phases of the supersymmetric standard model are
promoted to dynamical variables. This amounts to postulating the existence of
spontaneously broken global symmetries in the supersymmetry breaking sector.
The vacuum can then relax near a CP conserving point. As a consequence the
strong CP and supersymmetric CP problems may be solved by similar mechanisms.


title: One Loop Integrals at Finite Temperature and Density

abstract:
  The technique of decomposing Feynman diagrams at the one loop level into
elementary integrals is generalized to the imaginary time Matsubara formalism.
The three lowest integrals, containing one, two and three fermion lines, are
provided in a form that separates out the real and imaginary parts of these
complex functions, according to the input arguments, in a fashion that is
suitable for numerical evaluation. The forms given can be evaluated for
arbitrary values of temperature, particle mass, particle momenta and chemical
potential.


title: Ioffe-time distribution of quarks in the photon

abstract:
  We have analysed the Ioffe-time distribution of quarks in virtual photons
using Operator Product Expansion of the correlation function that determines
the matrix element of the corresponding quark string operator. The distribution
for a transversally polarised photon admits a spectral representation which can
be continued to the on-shell region $p^2 =0$. The resulting model Ioffe-time
distribution turns out to be larger than parametrisations of the available
$F_2^{\gamma}$ data. This result is linked to the slope of the quark
distribution at the origin, which comes out too large as well.


title: Multiplicity Distributions of Squeezed Isospin States

abstract:
  Multiplicity distributions of neutral and charged particles arising from
squeezed coherent states are investigated. Projections onto global isospin
states are considered. We show how a small amount of squeezing can
significantly change the multiplicity distributions. The formalism is proposed
to describe the phenomenological properties of neutral and charged particles
anomalously produced in hadronic and nuclear collisions at very high energies.


title: Status of the Minimal Supersymmetric Standard Model

abstract:
  Recent results in study of the Minimal Supersymmetric Standard Model as the
effective low energy theory give important hints for experimental search for
supersymmetry. Also, in the bottom-up approach to explore weak scale - GUT
scale connection, they constrain strongly physics at the GUT scale. Several
theoretical ideas about the GUT physics are in stunning agreement with the low
energy data.


title: Naturally Light Scalars

abstract:
  I argue that in certain chiral gauge theories composite scalars associated
with chiral symmetry breaking can be light (i.e. lighter than naive scaling
from QCD would suggest) without any fine-tuning. These scalars will be even
lighter in chiral gauge theories that produce chiral symmetry breaking without
confinement. I construct a model which demonstrates this last possibility.


title: Physics at a $\mu^+\mu^-$ Collider

abstract:
  A brief overview of the physics capabilities of a $\mu^+\mu^-$ collider is
given, with particular focus on special Higgs sector opportunities.


title:
Is $B \to X_s \gamma$ equal to $b \to s \gamma$ ? Spectator
  contributions to rare inclusive B decays

abstract:
  In $B \to X_s \gamma $ there are perturbative $QCD$ corrections at order
$\alpha_s$ not only to the single quark line process $ b \to s \gamma$ but also
coming from a set of diagrams where the weak interaction vertex involves a
gluon which interacts with the spectator quark in the B hadron. We discuss the
impact of the full set of these diagrams. These can influence the decay rate
and also the line shape of the photon spectrum as they favor a softer photon
energy than does the pure spectator decay $b \to s \gamma$. A subset of these
diagrams generate differences in the decay rates for charged and neutral B's ,
$B^+ \to X_s \gamma$ vs. $B^0 \to X_s \gamma$ which can be searched for
experimentally, although our calculation indicates that the effect will be hard
to observe. Bound state effects turn out to be required to give rise to
spectator corrections to the decay rate at order $\alpha_s$. The resulting
contribution to the total rate is rather small (of about $5 \% $ ), although
the effect is somewhat larger on portions of the photon spectrum.


title: A viable one-family technicolor model

abstract:
  We construct a one-family technicolor model which is consistent with the
precision experiments on the electroweak interaction. The Majorana mass of the
right-handed techni-neutrino is introduced and the techni-$U(1)_{B-L}$ symmetry
is gauged to obtain the correct breaking of the electroweak symmetry. The
tree-level kinetic mixing between the techni-$U(1)_{B-L}$ and $U(1)_Y$ gauge
bosons plays an important role for having the consistent value of the $S$
parameter.


title: Hadron '95 --- Summary: Part I

abstract:
  Part I of this summary is concerned with selected results on natural parity
states presented at this conference, in particular the glueball candidates the
$f_0(1510)$ and $\xi(2230)$. Unnatural parity and exotic states are discussed
by Suh-Urk Chung


title:
Controlling a Non-Polynomial Reduced Finite Temperature Action in the
  U(1) Higgs Model

abstract:
  An effective theory is constructed for the scalar electrodynamics via 2-loop
integration over all non-static fields and the screened electric component of
the vector-potential. Non-polynomial terms of the action are preserved and
included into the 2-loop calculation of the effective potential of the reduced
theory. Also the inclusion of some non-local terms is shown to be important.
The effect of non-polynomial operators on the symmetry restoring phase
transition is quantitatively compared to results from a local,
superrenormalisable approximate effective theory.


title:
$\chi_{c2} \to \rho\rho$ and the $rho$ polarization in massless
  perturbative QCD: how to test the distribution amplitudes

abstract:
  We compute the helicity density matrix of $\rho$ vector mesons produced in
the two-body decays of polarized $\chi_{c2}$'s in the framework of massless
perturbative QCD. The $\chi_{c2}$'s are either exclusively or inclusively
produced in $p \, \bar p$ or $p \, p$ interactions, via quark-antiquark
annihilation or gluon fusion. Our results show unambiguous significant
differences depending on the choice of the $\rho$ distribution amplitudes and
allow to discriminate between different proposed models.


title: Hadronic matrix elements of gluon operators in the instanton vacuum

abstract:
  We propose a method to evaluate hadronic matrix elements of QCD gluon
operators in the instanton vacuum. We construct the ground state of the
interacting instanton ensemble for non-zero $\vartheta$--angle using a
variational principle. A method to study the $\vartheta$--dependence of
observables on the lattice is suggested. We then derive the effective fermion
action, which allows to calculate hadronic correlation functions in a
$1/N_c$--expansion (Nambu--Jona-Lasinio type effective fermion theory). Gluon
operators are systematically represented as effective fermion operators.
Physical matrix elements are obtained after integrating the correlation
functions over fluctuations of the numbers of instantons. The influence of the
fermion determinant on the topological susceptibility is taken into account.
Our effective description gives matrix elements fully consistent with the trace
and $U(1)_A$ anomalies. The approach allows to consistently evaluate the
nucleon matrix elements of various gluon and mixed quark--gluon operators in a
chiral soliton picture of the nucleon.


title: Excess Dileptons in High-Energy Nucleus-Nucleus Collisions

abstract:
  It has been observed recently that while continuum dilepton production and
open charm production in high-energy $pA$ collisions can be described in terms
of the superposition of $pp$ collisions, dilepton yields in S+U collisions are
in excess of similar extrapolations. This feature can be explained as arising
from the interaction of gluons produced in different soft baryon-baryon
collisions, leading to additional open-charm pairs in nucleus-nucleus
collisions but not in $pA$ collisions.


title: Cascade Global Symmetry and Quark Mass Hierarchy

abstract:
  Cascade global symmetry and multi-vacuum expectation values are combined to
produce an {\bf initial} texture of the quark mass matrices. Required
corrections to the initial texture zeros ({\bf ITZ)} are all at the order of
$10^{-3}m_t$ or less. The possibility of {\bf radiative corrections} as the
source of the complete mass matrices is briefly discussed.


title: Antiquark Polarization inside the Proton is Small

abstract:
  Quark contributions to the proton spin as deduced from polarized DIS of
leptons off a nucleon target, and the octet baryon magnetic moments, can be
used to deduce the antiquark polarizations $\Delta_{\overline{q}}$ inside the
proton. In this way, the 1992 analysis by Karl is shown to imply
$\Delta_{\overline{q}}\simeq 0.$ Such a spin structure fits nicely into the
chiral quark interpretation of the proton spin and flavor puzzles.


title: Chiral quark perspective of the proton spin and flavor puzzles

abstract:
  The chiral quark model with a broken U(3) symmetry gives a simple and unified
account for the proton spin and flavor puzzles, as well as the octet baryon
magnetic moments.


title:
Axial Vector Couplings of the Nucleon in Chiral Quark Model
  Incorporating $ U(1)_A$ Anomaly Effects

abstract:
  Renormalization of the axial vector currents due to Goldstone loops is
studied in a simple extension of Manohar - Georgi chiral quark model which
incorporates $U(1)_A$ anomaly effects. The polarized strage quark sea in the
polarized nucleon results from different renormalization of the flavor singlet
and octet currents and is in reasonable agreement with the experiment.


title: Photonic production of P-wave states of B_c mesons

abstract:
  Numerical calculations for the production of $P$-wave levels of $B_c$
quarkonium in $\gamma\gamma$ collisions are performed in the leading
$O(\alpha_s^2\alpha_{em}^2)$ order of perturbation theory. The total
cross-section of $P$-wave state production is about 10 \% of that for the
$S$-wave levels. The contribution of fragmentation component ($6+6$ diagrams)
is low, and the basic contribution is determined by the recombination mechanism
($8$ Feynman diagrams). The gauge invariant term of the $\bar b\to B_c$
fragmentation ($6$ diagrams) quite accurately reproduces the result of the
fragmentation model, whereas there is a strong deviation of the $c\to B_c$
fragmentation term from the predictions of the fragmentation model.


title: Structural Aspects of the Proton in the Chiral Quark Model

abstract:
  We calculate with chiral symmetry the parton contents of the proton based on
a two-component wave function. The calculation results give significant
sea-quark contents and, especially, the intrinsic gluon polarization produced
at a more fundamental level.


title:
On the mass correction of heavy hadrons of arbitrary spin in heavy
  hadron effective theory

abstract:
  The mass correction forms of the arbitrary spin heavy hadrons are derived by
using the projection operator method. The Bjorken sum rule for finite mass is
derived by using the results of here.


title: On the mass correction of heavy meson effective theory

abstract:
  We derive the mass correction lagrangian of the heavy meson effective theory
by using the projection operator method. The next leading order of the mass
correction and the first order of the chiral expansion are given explicitely.We
also consider the mass correction weak lagrangian of the heavy mesons. Finally,
we give the $\it{D}^{*+}\to \it{D}^o \pi^{+}$ decay.


title: Polarization effects in electroweak vector boson productions

abstract:
  The electroweak production processes of vector bosons, $e^+ e^- \rightarrow Z
\gamma$, $\gamma e \rightarrow Ze$, and $\gamma e \rightarrow W \nu$ are
considered simultaneousely and in the Standard model the covariant polarization
density matrices of vector bosons for these processes are obtained explicitly
from one of the processes, $\gamma e \rightarrow Z e$. The effect of the photon
polarization as well as the vector meson polarization is considered and some
special cases are discussed.


title: Present Status of Polarized Parton Distributions

abstract:
  A review of the present knowledge on polarized parton distributions is given.
The effects of perturbative evolution on these distributions are discussed
qualitatively and a comparison of various recent parametrizations is made.


title: Moment analysis of energy spectra and the effect of running coupling

abstract:
  Single particle inclusive energy spectra in $e^+e^-$ annihilation are
analyzed in terms of moments. By assuming Local Parton Hadron Duality (LPHD),
experimental data in a wide c.m. energy range from 3 GeV up to LEP energy are
compared to the theoretical predictions of Modified Leading Log Approximation
(MLLA) of QCD with and without taking into account the running of $\alpha_s$.
MLLA with running coupling (Limiting Spectrum) is found to reproduce
experimental results very well, while the model with fixed coupling is
inconsistent with data. Rescaled cumulants are shown to be sensitive to the
running of $\alpha_s$ in the asymptotic regime, while the Lorentz-invariant
distribution, $E dn/d^3p$, points out this effect at very small energy $E$ of
few hundreds MeV. These results give a direct evidence of the running of the
QCD coupling in inclusive energy spectra and lend further support to the LPHD
picture.


title: Properties of the Strange Axial Mesons in the Relativized Quark Model

abstract:
  We studied properties of the strange axial mesons in the relativized quark
model. We calculated the $K_1$ decay constant in the quark model and showed how
it can be used to extract the $K_1 (^3P_1) - K_1 (^1P_1)$ mixing angle
($\theta_K$) from the weak decay $\tau \to K_1 \nu_\tau$. The ratio $BR(\tau
\to \nu_\tau K_1 (1270))/BR(\tau\to \nu_\tau K_1(1400))$ is the most sensitive
measurement and also the most reliable since the largest of the theoretical
uncertainties factor out. However the current bounds extracted from the
TPC/Two-Gamma collaboration measurements are rather weak: we typically obtain
$-30^o \lesssim \theta_K \lesssim 50^o$ at 68\% C.L. We also calculated the
strong OZI-allowed decays in the pseudoscalar emission model and the flux-tube
breaking model and extracted a $^3P_1 - ^1P_1$ mixing angle of $\theta_K \simeq
45^o$. Our analysis also indicates that the heavy quark limit does not give a
good description of the strange mesons.


title: Lowering alpha_s by flipping SU(5)

abstract:
  We show that the prediction for $\alpha_s(M_Z)$ in flipped SU(5) is naturally
lower than in minimal SU(5), and that the former can accommodate the full range
of $\alpha_s(M_Z)$ presently allowed by experiment. Our computations include
two-loop ($\delta_{\rm 2loop}$) and light ($\delta_{\rm light}$) and heavy
($\delta_{\rm heavy}$) threshold effects. Unlike minimal SU(5), in flipped
SU(5) the heavy threshold effects can naturally decrease the predicted value of
$\alpha_s(M_Z)$. We also show that the value of the proton lifetime into the
dominant channel $p\to e^+\pi^0$ is within the observable range at
SuperKamiokande, and should discriminate against minimal supersymmetric SU(5),
where the dominant mode is $p\to\bar\nu K^+$.


title:
BFKL QCD Pomeron in High Energy Hadron Collisions and Inclusive Dijet
  Production

abstract:
  We calculate inclusive dijet production cross section in high energy hadron
collisions within the BFKL resummation formalism for the QCD Pomeron. We take
into account the Pomerons which are adjacent to the hadrons. With these
adjacent Pomerons we define a new object - the BFKL structure function of
hadron - which enables one to calculate the inclusive dijet production for any
rapidity intervals. We present predictions for the dijet K-factor and azimuthal
angle decorrelation. Estimations for some NLO BFKL corrections are also given.
  (To appear in the Proceedings of the Workshop on Particle Theory and
Phenomenology, the International Institute of Theoretical and Applied Physics,
Ames, Iowa, May 1995)


title: The Finite-Temperature Feynman Propagator in Operator Form

abstract:
  In momentum space the Feynman propagator $D_{F}(k)$ at non-zero temperature
is defined by a simple dispersion relation with the familiar property of being
an even function of $k^{0}$ and analytic for Re$(k^{0})^{2}>0$. The coordinate
space form of the propagator $D_{F}(x)$ is expressed directly in terms of
matrix elements of the field operator and requires a new type of operator
ordering.


title: Four-Fermion Dynamics and Fermion Masses

abstract:
  Four-fermion operators with large anomalous dimension may feed down mass to
quarks and leptons from a heavy fourth family. No technicolor sector is
required. A model illustrates the origin of the large top mass along with quark
mass hierarchies and mass mixings.


title: Properties of Strangelets at Finite Temperature in Liquid Drop Model

abstract:
  A comprehensive study of the properties of strangelets at zero and finite
temperature is presented within the framework of liquid drop model, including
the essential finite size effects. Strong parameter dependences of the
properties are found and discussed.


title: $S$-matrix description of the finite-temperature noneqilibrium media

abstract:
  The paper contains the real-time perturbation theory for description of a
statistical system with the nonuniform temperature distribution. the formalism
based on the Wigner-functions approach. The perturbation theory is formulated
in terms of the local-temperature Green functions.


title:
Limits on direct detection of neutralino dark matter from b -> s gamma
  decays

abstract:
  We analyze the rate of detection of minimal supersymmetric neutralino dark
matter in germanium, sapphire and sodium iodide detectors, imposing
cosmological and recent accelerator bounds including those from \bsg\ decay. We
find, in contrast with several other recent analyses, that although the \bsg\
constraint reduces the number of viable models, models still remain where the
counting rate in solid state detectors exceeds 10 kg$^{-1}$ day$^{-1}$.


title: Heavy Flavour Production

abstract:
  We review the status of heavy flavour production in QCD. Comparison of
experimental and theoretical results for top and bottom production are given.
Selected topics in charm production are also discussed.


title: Low Energy Sum Rules For Pion-Pion Scattering and Threshold Parameters

abstract:
  We derive a set of sum rules for threshold parameters of pion-pion scattering
whose dispersion integrals are rapidly convergent and are dominated by S- and
P-waves absorptive parts. Stringent constraints on some threshold parameters
are obtained.


title: Measuring Top Quark Electroweak Dipole Moments

abstract:
  We analyze the pair-production of top quarks in polarized $e^+e^-$ scattering
in the presence of electroweak dipole moments. For this, we consider two
$CP$-odd observables which probe both the real and the imaginary parts of these
moments. Polarizing the electron beam turns out to be a main asset.


title: Summary of Gluonium95 and Hadron95 Conferences by

abstract:
  A summary of two conferences on the hadron and gluonium spectrum is given,
with personal comments on the status of the best candidates for gluonium or
non-qq states, such as f0(1370), f0(1500), fJ(1720), fJ(2230), eta(1410),
eta(1460), and f1(1420).


title: Improved version of the eikonal model for absorbing spherical particles

abstract:
  We present a new expression of the scattering amplitude, valid for spherical
absorbing objects, which leads to an improved version of the eikonal method
outside the diffraction region. Limitations of this method are discussed and
numerical results are presented and compared successfully with the Mie theory.


title:
The chiral phase transition in a random matrix model with molecular
  correlations

abstract:
  The chiral phase transition of QCD is analyzed in a model combining random
matrix elements of the Dirac operator with specially chosen non-random ones.
The special form of the latter is motivated by the assumption that the
fermionic quasi-zero modes associated with instanton and anti-instanton
configurations determine the chiral properties of QCD. Our results show that
the degree of correlation between these modes plays the decisive role. To
reduce the value of the chiral condensate by more than a factor of 2 about 95
percent of the instantons and anti-instantons must form so-called molecules.
This conclusion agrees with numerical results of the Stony Brook group.


title:
Electroweak Penguin Contributions in $B^-(\overline {B_d^0}) \to PP$ and
  $PV$ decays Beyond Leading Logarithms

abstract:
  Using the next-to-leading order low energy effective Hamiltonian for $|\Delta
B|=1$, $\Delta C=\Delta U=0$ transitions, the contributions of electroweak
penguin operators in $ B^-(\overline {B_d^0})\rightarrow PP$ and $PV$ decays
are estimated in the standard model. We find that, for some channels, the
electroweak penguin effects can enhance or reduce the QCD penguin and/or tree
level contributions by at least $30\%$, and can even play dominant role.


title: Flavors and Horizontal Symmetries

abstract:
  After a brief introduction to what are the basic flavor questions to be
addressed, I introduce the underlying ideas of horizontal symmetries, with
group $G_H$. For the purposes of specific model building, it is useful to
classify models according to the scale at which $G_H$ is broken. I consider the
three cases: below $m_t$; somewhat above $m_t$; and at $M_{GUT}$. After a
discussion of the shadow sector in the $E_6 \times E_8'$ superstring, there is
a summary.


title:
Influence of Additional Fermions and Gauge Bosons on
  $Re(\epsilon'/epsilon)$

abstract:
  The CP violation parameter $Re(\epsilon'/\epsilon)$ has previously been
calculated in the standard model and the result depends on the top quark mass
in an exciting way. We consider how the result is modified in two specific
extensions of the standard model. The first adds only fermions, an extra
vector-like quark doublet, and tends to reduce $Re(\epsilon'/\epsilon)$. The
second contains three extended families with the third family treated
differently and additional gauge bosons - the 331 model - and can accommodate
larger values of $Re(\epsilon'/\epsilon)$ for a given $m_t$. When the
experimental values of $m_t$ and $Re(\epsilon'/ \epsilon)$ are known more
accurately, it will allow discrimination between theories. If the lower
experimental number $Re(\epsilon'/\epsilon) = (0.74 \pm 0.60) \times 10^{-3}$
(Fermilab, E731) is confirmed and $m_t$ is near the value 175GeV the standard
model is acceptable. But, if the higher value $Re(\epsilon'/\epsilon) = (2.3
\pm 0.65) \times 10^{-3}$ (CERN, NA31) persists, a dynamics like the 331 model
where the third family is treated differently from the first two and there
exist additional gauge bosons seems to be favored.


title: Factorization in Semi-Inclusive Polarized Deep Inelastic Scattering

abstract:
  We calculate and analize the ${\cal{O}}(\alpha_s)$ one-particle inclusive
cross section in polarized deep inelastic lepton-hadron scattering, using
dimensional regularization and the HVBM prescription for $\gamma_5$. We discuss
the factorization of all the collinear singularities related to the process,
particularly those which are absorbed in the redefinition of the spin dependent
analogue of the recently introduced fracture functions. This is done in the
usual $\overline{MS}$ scheme and in another one, called $\overline{MS_p}$,
which factorizes soft contributions and guarantees the axial current
(non)conservation properties.


title: Polarized Beam Jets

abstract:
  Handedness and a left-right asymmetry have been proposed as methods of
probing the polarization of hard jets. If the analyzing powers for these
observables are substantial they would provide useful tools for probing
polarized hard scattering. This paper proposes that comparing these to the
corresponding quantities in beam jets in polarized hadron-hadron collisions
would be useful. These would shed light on the similarities and differences
between the fragmentation of hard and soft jets. They would also suggest
whether there is any useful possibility of measuring jet polarization. The
left-right asymmetry of beam jets has already been measured and is large. But
measurements of the handedness of beam jets have still to be done. They could
be done in an upgraded HERMES detector at HERA.


title: Confinement and the Transverse Lattice

abstract:
  The status of the transverse lattice formulation of light-front QCD is
reviewed. It is explained how confinement arises in this formulation for large
lattice spacing. The nonperturbative renormalization procedure is outlined in
general and a more detailed discussion is given for the case of
$QCD_{2+1}(N_C\rightarrow \infty)$.


title:
Self-Couplings of Electroweak Bosons: Theoretical Aspects and Tests at
  Hadron Colliders

abstract:
  The current theoretical understanding of anomalous gauge boson couplings is
reviewed, and the direct measurement of these couplings in present and future
hadron collider experiments is briefly discussed.


title:
Symmetry breaking induced by top quark loops from a model without scalar
  mass

abstract:
  Considering the standard model as an effective electroweak theory, in which
we have no scalar mass term in the Higgs potential $(\mu^2=0)$, we show that
the spontaneous symmetry breaking of $SU(2)_L \times U(1)$ can be induced by
top loops. The Higgs boson mass obtained is smaller than 300 GeV.


title: CP-Violation For $B \to X_sl^+l^-$ Including Long-Distance Effects

abstract:
  We consider the CP violating effect for $B\to X_sl^+l^-$ process, including
both short and long distance effects. We obtain the CP asymmetry parameter and
present its variation over the dilepton mass.


title: Excited states of heavy baryons in the Skyrme model

abstract:
  We obtain the spectra of excited heavy baryons containing one heavy quark by
quantizing the exactly-solved heavy meson bound states to Skyrme soliton. The
results are comparable to the recent experimental observations and quark model
predictions, and are consistent with the heavy quark spin symmetry. However,
somewhat large dependence of the results on the heavy quark mass strongly calls
for the incorporation of the soliton-recoil effects.


title: EW Precision Analysis and the Higgs Mass

abstract:
  Two topics on the standard electroweak theory are discussed based on its
remarkable success in precision analyses. One is a test of structure of the
radiative corrections to the weak-boson masses as a further precision analysis.
The other is an indirect Higgs-boson search through the radiative corrections
to the various quantities measured at LEP.


title: Heavy flavours from QCD spectral sum rules

abstract:
  We present a summary update of the QCD spectral sum rule (QSSR) results for
the running and {\it perturbative pole} quark masses, the $f_D$ and $f_B$
leptonic decay constants, the heavy-to-light and heavy-to-heavy exclusive
transition-form factors. Analytic expressions of these latter quantities are
presented, which give a deeper understanding of their $q^2$- and infinite
mass-behaviours. A short comparison of the QSSR results with alternative
approaches is done.


title:
Towards a Nonequilibrium Quantum Field Theory Approach to Electroweak
  Baryogenesis

abstract:
  We propose a general method to compute $CP$-violating observables from
extensions of the standard model in the context of electroweak baryogenesis. It
is alternative to the one recently developed by Huet and Nelson and relies on a
nonequilibrium quantum field theory approach. The method is valid for all
shapes and sizes of the bubble wall expanding in the thermal bath during a
first-order electroweak phase transition. The quantum physics of $CP$-violation
and its suppression coming from the incoherent nature of thermal processes are
also made explicit.


title: Strongly coupled positronium in a chiral phase

abstract:
  Strongly coupled positronium, considered in its pseudoscalar sector, is
studied in the framework of relativistic quantum constraint dynamics. Case's
method of self-adjoint extension of singular potentials, which avoids explicit
introduction of regularization cut-offs, is adopted. It is found that, as the
coupling constant \alpha increases, the bound state spectrum undergoes an
abrupt change at the critical value \alpha = \alpha_c = 1/2. For \alpha >
\alpha_c, the mass spectrum displays, in addition to the existing states for
\alpha < \alpha_c, a new set of an infinite number of bound states concentrated
in a narrow band starting at mass W=0. In the limit \alpha going to \alpha_c
from above, these states shrink to a single massless state with a mass gap with
the rest of the spectrum. This state has the required properties to represent a
Goldstone boson and to signal a spontaneous breakdown of chiral symmetry. It is
suggested that the critical coupling constant \alpha_c be viewed as a possible
candidate for an ultra- violet stable fixed point of QED, with a distinction
between two phases, joined to each other by a first-order chiral phase
transition.


title:
Remarks on the Inclusive Decays $\Lambda_b \to X_s \gamma$ and
  $\Lambda_b \to X_c l \bar{\nu}_l$

abstract:
  We consider the effects of quark-binding on the angular distribution and
polarization characteristics of the inclusive decays $\Lambda_b \to X_s \gamma$
and $\Lambda_b \to X_c l \bar{\n}_l$ $(l=e, \tau)$, using the methods of heavy
quark effective theory.


title: The Future of Top Physics at the Tevatron and LHC

abstract:
  I review the prospects for measuring the properties of the top quark at the
Tevatron, with an integrated luminosity of 2 fb$^{-1}$ or more, and at LHC in
the early running at instantaneous luminosities of
$10^{32}-10^{33}~cm^{-2}~s^{-1}$.


title: Topological Defects and Inflation

abstract:
  In the context of supersymmetric models, we analyze the production of
topological defects at the end of inflation driven by a conjugate pair of
inflaton fields which are non-singlets under the continuous symmetry group of
the theory. We find that magnetic monopoles of mass on the order of $10^{13}\
GeV$ can survive inflation and be present in our galaxy at an observable level.
We also consider cosmic strings as well as domain walls.


title: The Problem Of Scales: Renormalization and All That

abstract:
  I explain the methods that are used in field theory for problems involving
typical momenta on two or more widely disparate scales. The principal topics
are: (a) renormalization, which treats the problem of taking an ultra-violet
cut-off to infinity, (b) the renormalization group, which is used to relate
phenomena on different scales, (c) the operator product expansion, which shows
how to obtain the asymptotics of amplitudes when some of its external momenta
approach infinity.


title:
An N=2 SUSY Gauge Model for Dynamical Breaking of the Grand Unified
  SU(5) Symmetry

abstract:
  We construct an extension of the recently proposed dynamical model for the
breaking of SU(5)$_{\rm GUT}$ gauge symmetry, in which a pair of massless
chiral supermultiplets for Higgs doublets are naturally obtained. We point out
that a model at a specific point in the parameter space of superpotential is
regarded as a low-energy effective theory of an N=2 supersymmetric gauge model
for the strongly interacting hypercolor sector.


title: SU(3) Flavor Dependence of the Heavy Quark Symmetry

abstract:
  SU(3) flavor dependence of the leading and subleading parameters appeared in
the heavy quark expansion of the heavy-light mesons are systematically analyzed
by using QCD sum rules.


title: Gauge-Yukawa Unification and the Top-Bottom Hierarchy

abstract:
  The consequences of Gauge-Yukawa Unification (GYU) in supersymmetric unified
models on low energy physics are analyzed. We find that the observed top-bottom
mass hierarchy can be explained by supersymmetric GYU and different models can
be experimentally distinguished if the top quark mass does not exceed the value
$\sim 185$ GeV.


title: U(1) Goldberger-Treiman Relation and Its Connection to the Proton Spin

abstract:
  The U(1) Goldberger-Treiman (GT) relation for the axial charge $g_A^0$ is
reexamined. It is stressed that the isosinglet GT relation in terms of the
$\eta_0$ holds irrespective of the quark masses and the axial anomaly. We
pointed out that the identification of the $\eta_0-N$ and $\dk-N$coupling terms
with the quark and gluon spin components respectively in a proton is possible
but valid only in the chiral-invariant factorization scheme. In general, the
two-component U(1) GT relation can be identified in a gauge-invariant way with
connected and disconnected insertions. The observation that $(\sqrt{3}f_\pi
/2m_N)\getao$ is related to the connected insertion i.e., the total valence
quark contribution to the proton spin enables us to determine the physical
coupling constants $\getap$ and $\geta$ from the GT relations for $g_A^0$ and
$g_A^8$. We found $\getap=3.4$ and $\geta=4.7\,$.


title: Methods of Supersymmetry Breaking

abstract:
  This is a review of basic ideas and mechanisms encountered in the
supersymmetry breaking problem at the global level, in supergravity models, and
in superstring theory.


title: String junction as a baryonic constituent

abstract:
  We extend the model for QCD string with quarks to consider the Mercedes Benz
string configuration describing the three-quark baryon. Under the assumption of
adiabatic separation of quark and string junction motion we formulate and solve
the classical equation of motion for the junction.We dare to quantize the
motion of the junction, and discuss the impact of these modes on the baryon
spectra.


title: Hadronic Final States

abstract:
  The following aspects of hadronic final states in deep inelastic lepton
scattering are reviewed: measuring $alpha_s$ from multi-jet production rates
and event shapes; alternative jet algorithms for DIS; power-suppressed
corrections to event shapes; comparing jet fragmentation in $e^+e^-$
annihilation and DIS; final states in the BFKL and CCFM formulations of
small-$x$ dynamics; exotic (instanton-induced) final states.


title: Calculation of the anomalous $\gamma \pi ^* \to \pi \pi $ form factor

abstract:
  The form factor for the anomalous process $\gamma \pi ^* \to \pi \pi$,
$F^{3\pi}(s,t,u)$, is calculated as a phenomenological application of the QCD
Dyson-Schwinger equations. The chiral-limit value dictated by the
electromagnetic, anomalous chiral Ward identity, $F^{3\pi}(0,0,0)= e
N_c/(12\pi^2 f_\pi^3)$, is reproduced, {\it independent} of the details of the
modelling of the gluon and quark 2-point Schwinger functions. Using a
parametrisation of the dressed $u$-$d$ quark 2-point Schwinger function that
provides a good description of pion observables, such as $\pi$-$\pi$
scattering-lengths and the electromagnetic pion form factor, $F^{3\pi}(s,t,u)$
is calculated on a kinematic range that proposed experiments plan to explore.
Our result confirms the general trend of other calculations; i.e., a monotonic
increase with $s$ at fixed $t$ and $u$, but is uniformly larger and exhibits a
more rapid rise with $s$.


title: Hybrid states with heavy quarks

abstract:
  Model-independent features of hybrid states with heavy quarks and adiabatic
approximation for such systems are discussed.These general arguments are
applied to the QCD-based constituent gluon model.The leading- order Hamiltonian
is derived from the general formalism. The masses of heavy quarks hybrids,
including charmonium hybrid states,are calculated. We predict $c\bar c g$
hybrids at 4.0$\pm$0.1 GeV and $b \bar b g$ ones at 10.5$\pm$0.1 GeV.Comparison
with some other models are made.


title:
$B^0$--$\overline{B}^0$ mixing and $\epsilon_K$ parameter in the minimal
  supergravity model

abstract:
  \bb mixing and a CP violation parameter in \kk mixing $\epsilon_K$ are
studied in the minimal supergravity model. We solve the one-loop
renormalization group equations for the minimal supersymmetric standard model
(MSSM) parameters numerically in order to determine the masses and mixings of
the supersymmetric particles, while all off-diagonal (generation mixing)
elements and phases of Yukawa coupling matrices and those of squark mass
matrices are taken into account. Applying the radiative electroweak symmetry
breaking condition and phenomenological constraints including the recent
measurement of the \bsg inclusive branching ratio, we obtain the allowed
parameter region. We have found that the present constraints still allow a
parameter region where both \bb mass splitting $\Delta M_B$ and $\epsilon_K$
are $\sim 20$\% larger than the standard model values. By explicit numerical
calculations, we have also found that the complex phase of \bb mixing matrix
element in this model is almost the same as the standard model value in a good
accuracy in the whole allowed parameter region. It is shown that $\Delta M_B$
and $\epsilon_K$ can put useful constraints on the supersymmetry's parameter
space when the Cabibbo-Kobayashi-Maskawa matrix elements are determined through
the measurements of CP violations in $B$ decay with future $B$-factories.


title: Supersymmetry: Where it is and how to find it

abstract:
  We present a pedagogical, but by no means complete, review of weak scale
supersymmetry phenomenology. After a general introduction to the new particles
that must be present in any supersymmetric framework, we describe how to write
down their interactions with one another as well as with the particles of the
Standard Model. We then elucidate the assumptions underlying the Minimal
Supersymmetric Model as well as the more restrictive minimal supergravity GUT
model with the radiative breaking of electroweak symmetry. These models serve
to guide our thinking about the implications of supersymmetry for experiments.
To facilitate our study of signatures of supersymmetric particles at high
energy colliders, we describe the decay patterns of sparticles as well as their
production mechanisms in $e^+e^-$ and hadron-hadron collisions. We then discuss
how sparticles may be searched for in on-going experiments at the Tevatron and
at LEP. We review phenomenological constraints on supersymmetric particle
masses from non-observation of any signals in these experiments, and also
briefly discuss constraints from low energy experiments and from cosmology.
Next, we study new strategies by which supersymmetric particles may be searched
for at supercolliders, and also what we can learn about their properties
(masses, spins, couplings) in these experiments. A determination of sparticle
properties, we will see, may provide us with clues about the nature of physics
at the ultra-high scale. After a brief discussion of possible extensions of the
minimal framework and the implications for phenomenology, we conclude with our
outlook for the future.


title: Are We Really Measuring the $\rho$-Value?

abstract:
  The ``normal'' analysis of $\pbar p$ and $pp$ elastic scattering uses a
`spinless' Coulomb amplitude, \ie a Rutherford amplitude
($2\sqrt{\pi}\alpha/t$) multiplied by a Coulomb form factor $G^2(t)$, an {\em
ansatz} that pretends that the nucleon does not have any magnetic scattering.
In this note, we investigate the role of the anomalous magnetic moment of the
nucleon, $\kappa \approx 1.79$. Given the method of analysis currently used by
most published experiments, we conclude that the current experimentally
inferred values of $\rho$ for $\pbar p$ should be {\em systemeatically lowered}
by $\approx 0.005$---0.0100 and, correspondingly, the $\rho$ values for $pp$
should be {\em systematically raised} by the same amount. We discuss the
theoretical uncertainties and a method of experimentally minimizing them.


title: Increasing R_b and Decreasing R_c with New Heavy Quarks

abstract:
  If the b and c quarks mix with new heavy quarks of weak isospin I_3 = -1 and
0 respectively, then the Z -> b b(bar) (c c(bar)) rate is necessarily greater
(smaller) than that of the standard model. This may be the reason for the R_b
excess and R_c deficit observed at LEP. A possible consequence of this scenario
is the prospective discovery of a new quark x with the dominant decay x -> c h,
then h -> b b(bar), where h is a neutral Higgs boson.


title:
The High Energy Behavior of the Forward Scattering Parameters---An
  Amplitude Analysis Update

abstract:
  Utilizing the most recent experimental data, we reanalyze high energy \pbar p
and pp data, using the asymptotic amplitude analysis, under the assumption that
we have reached `asymptopia'. This analysis gives strong evidence for a $\log
\,(s/s_0)$ dependence at {\em current} energies and {\em not} $\log^2 (s/s_0)$,
and also demonstrates that odderons are {\em not} necessary to explain the
experimental data.


title: QCD and Diffraction in DIS

abstract:
  Coherence phenomena, and the non-universality of parton structure of the
effective Pomeron are explained. New hard phenomena directly calculable in QCD
such as diffractive electroproduction of states with $M^2\ll Q^2$ as well as
new options to measure the light-cone wave functions of various hadrons are
considered. An analogue of Bjorken scaling is predicted for the diffractive
electroproduction of $\rho$ mesons at large momentum transfers and for the
production of large rapidity gap events, as observed at HERA. A
phenomenological QCD evolution equation is suggested to calculate the basic
characteristics of the large rapidity gap events. The increase of parton
densities at small $x$ as well as new means to disentangle experimentally soft
and hard physics are considered. We discuss constraints on the increase of deep
inelastic amplitudes with $Q^2$ derived from unitarity of the S matrix for
collisions of wave packets. New ways to probe QCD physics of hard processes at
large longitudinal distances and to answer the long standing problems on the
origin of the Pomeron are suggested. Unresolved problems and perspectives of
small $x$ physics are also outlined.


title: Expectations for Supersymmetric Dark Matter Searches Underground

abstract:
  We consider the neutralino as a dominant Dark Matter particle in the galactic
halo and investigate some general issues of direct Dark Matter searches via
elastic neutralino-nucleus scattering. On the basis of conventional assumptions
about the nuclear and nucleon structure we analyse constraints on SUSY model
parameter space accessible by the direct Dark Matter searches. This analysis
shows that Dark Matter detectors fall into the THREE different categories with
respect to their sensitivity to different groups of the SUSY model parameters.
We calculate the event rate for various experimentally interesting isotopes
within the Minimal Supersymmetric Standard Model (MSSM) taking into account the
known accelerator and cosmological constraints on the MSSM parameter space. We
investigate the role of nuclear spin in elastic neutralino - nucleus
scattering. It is found that the contribution of the spin-dependent interaction
to this process is subdominant for nuclei with atomic weights A > 50.


title: Phenomenology of Charm and Bottom Production

abstract:
  We discuss the renormalization and factorization scale dependence of charm
and bottom production both at fixed-target energies and at present and future
colliders. We investigate whether distributions calculable at leading order can
be extrapolated to next-to-leading order by a constant multiplicative factor.


title: B Meson Form Factors and Exclusive Decays

abstract:
  We present results for the $B \rightarrow \pi$ and $D\rightarrow \pi$ form
factors derived from QCD sum rules on the light-cone. Our predictions are
compared with experiment and used to extract the quark mixing parameter
$|V_{ub}|$ from a recent CLEO measurement of $B \ra \pi l^+ \nu$. Furthermore,
we discuss the factorization approximation for exclusive nonleptonic matrix
elements, and describe a first QCD estimate of the nonfactorizable contribution
to the amplitude of $B \rightarrow J/\psi K $.


title:
Small-x Parton Densities from HERA and the Ultra-High Energy
  Neutrino-Nucleon Cross Sections

abstract:
  In light of recent measurements of the nucleon structure function in the
small-$x$ deep-inelastic regime at HERA and the consequently improved
theoretical understanding of the quark distributions in this range of parton
fractional momentum, we present new results for the neutrino-nucleon cross
section at ultra high energies, up to $ E_{\nu} \sim 10^{21}$ eV. The results
are relevant to deep underground muon detectors looking for such neutrinos. For
$\simeq 10^{20}$ eV neutrinos, our cross sections are about a factor of $4$ to
$10$ times larger than the previously reported results by Reno, Quigg and
Walker. We discuss implications of this new neutrino-nucleon cross section for
a variety of current and future neutrino detectors.


title:
Like-Sign Charged Higgs Boson Production in $e^-e^-$ Collisions at the
  NLC

abstract:
  We consider the production of a pair of like-sign charged Higgs bosons in
$e^-e^-$ collisions at the NLC within the context of several electroweak models
with extended symmetry breaking sectors. We find that the rate for this
process, which proceeds through $W^-W^-$ fusion, is a very sensitive probe of
the nature of these extended Higgs sectors and that the corresponding cross
sections can vary by as much as several orders of magnitude at NLC energies.
(Talk presented at the Santa Cruz Workshop on $e^-e^-$ Physics at the NLC,
University of California, Santa Cruz, September 4-5, 1995.)


title:
On Deuteron Spin Dependent Structure Function $ g_{2}(x)$ in
  Relativistic Model of Deuteron

abstract:
  The spin dependent deuteron structure functions are investigated in the
relativistic model of deuteron. It is shown that the deuteron structure
function $g_{2}(X)$ can be considered properly only in the infinite momentum
frame where the virtual photon has pure transverse components
($q_{0}=-q_{3}\rightarrow 0$ at $ P\rightarrow \infty $), whereas in the
conventional Breit frame the impulse approximation for $g_{2}(X)$ may be
violated due to $q\bar{q}$ pair creation by the virtual photon. It is shown
that due to relativistic effects the deuteron structure function $g_{2}(X)$ has
a nontrivial contribution determined by first derivative of the nucleon
structure function $g_{1}(x)$. Such contribution is small but it increases when
$X \rightarrow 1$. It may achieve about 10 \% at $ X \sim 0.75$ and could be
essentially larger for the transverse structure function $g_{\perp}(X).$


title: The Condensed Matter Limit of Relativistic QFT

abstract:
  I study how to apply relativistic quantum field theory to condensed matter
systems. The motivation for this is examined and then two separate elements are
considered. First we identify the precise relationship between relativistic and
non-relativistic fields. Second we consider the need for a chemical potential
and how one includes this in static and dynamical calculations.


title:
Manifestations of Strong Electroweak Symmetry Breaking in $e^-e^-$
  Scattering

abstract:
  We analyze the incidence on polarized $e^-e^-$ scattering of the trilinear
and quartic anomalous gauge couplings which arise in the realm of a non-linear
realization of electroweak symmetry breaking.


title:
Transverse Polarization of Top Quark Pairs at the Tevatron and the Large
  Hadron Collider

abstract:
  We investigate the prospects to observe effects of transverse polarization of
top quarks in $pp,p\bar{p}\to t\bar{t}X$. QCD absorptive parts generate a
polarization of top quarks and antiquarks transverse to the production plane in
the partonic processes $q\bar{q}\to t\bar{t}$ and $gg\to t\bar{t}$, which
reaches values of a few percent. These perturbative QCD effects are decreased
at the hadronic level. A measurement through momentum correlations among the
$t$ and $\bar{t}$ decay products will be difficult both at an upgraded Tevatron
and at the LHC.


title:
The complete tree-level result up to order $1/Q$ for polarized
  deep-inelastic leptoproduction

abstract:
  We present the results of the tree-level calculation of deep-inelastic
leptoproduction, including polarization of target hadron and produced hadron.
We also discuss the dependence on transverse momenta of the quarks, which leads
to azimuthal asymmetries for the produced hadrons.


title:
The two-fermion vector potential of constraint theory from Feynman
  diagrams

abstract:
  The relativistic fermion-antifermion bound state vector potential of
constraint theory is calculated, in perturbation theory, by means of the
Lippmann-Schwinger type equation that relates it to the scattering amplitude.
Leading contributions of n-photon exchange diagrams are calculated in an
approximation scheme that adapts eikonal approximation to the bound state
problem. They produce terms proportional, in three-dimensional x-space, to
$(\alpha/r)^n$. The series of leading contributions is summed.


title: Lepton Flavor Violation in SUSY-SO(10) with Predictive Yukawa Texture

abstract:
  We analyze the scalar lepton mass matrices in a supersymmetric SO(10) grand
unified model with soft SUSY breaking terms generated at Planck scale and a
Georgi-Jarslkog Yukawa texture at GUT scale induced by higher dimensional
operators. This model predicts lepton flavor violation. The predictive features
of the Georgi-Jarlskog texture are used to estimate branching ratios for the
radiative decays $e_{a} \rightarrow e_{b}+\gamma,$ and we find rates that could
provide an experimental test for this kind of model.


title: The Spin Structure of the Nucleon in the Asymptotic Limit

abstract:
  In analogy to the Altarelli-Parisi equation for the quark and gluon helicity
contributions to the nucleon spin, we derive an evolution equation for the
quark and gluon orbital angular momenta. The solution of the combined equations
yields the asymptotic fractions of the nucleon spin carried by quarks and
gluons: $3n_f/(16+3n_f)$ and $16/(16+3n_f)$, respectively, where $n_f$ is the
number of active quark flavors. These are identical to the well-known
asymptotic partitions of the nucleon momentum between quark and gluon
contributions. We show that the axial-anomaly contribution to the quark
helicity is cancelled by a similar contribution to the quark orbital angular
momentum, making the total quark contribution to the nucleon spin anomaly-free.


title: Thermal variational principle and gauge fields

abstract:
  A Feynman-Jensen version of the thermal variational principle is applied to
hot gauge fields, Abelian as well as non-Abelian: scalar electrodynamics
(without scalar self-coupling) and the gluon plasma. The perturbatively known
self-energies are shown to derive by variation from a free quadratic
(''Gaussian'') trial Lagrangian. Independence of the covariant gauge fixing
parameter is reached (within the order $g^3$ studied) after a reformulation of
the partition function such that it depends on only even powers of the gauge
field. Also static properties (Debye screening) are reproduced this way. But
because of the present need to expand the variational functional, the method
falls short of its potential nonperturbative power.


title:
A note on Majorana neutrinos, leptonic CKM and electron electric dipole
  moment

abstract:
  The electric dipole moment of the electron, $d_e$, is known to vanish up to
thre e-loops in the standard model with massless neutrinos. However, if
neutrinos are massive Majorana particles, we obtain the result that $d_e$
induced by leptonic CKM mechanism is non-vanishing at two-loop order, and it
applies to all massive Majorana neutrino models.


title:
Extraction of the Ratio of the N^*(1535) Electromagnetic Helicity
  Amplitudes from Eta Photoproduction off Neutrons and Protons

abstract:
  Using the recent precise measurements of eta photopro- duction in proton and
deuteron targets, we extract the ratio of the helicity amplitudes A^n_1/2 /
A^p_1/2, for the excitation of N^*(1535), in the effective Lagrangian approach,
It is fairly model-independent, free from the final-state interaction effects,
and negative as predicted by the quark models. We stress the importance of
polarization observables in further elucidation of the N^*(1520)
photoexcitation amplitudes.


title: New Constraints on Superpartner Masses

abstract:
  We consider the Minimal Supersymmetric Standard Model (MSSM) without imposing
relations on the superpartner masses that arise in grand unified theories.
Given an arbitrary pattern of superpartner masses (consistent with experimental
constraints), it may happen that the scalar potential is actually unstable,
even though all scalar masses-squared are positive at the weak scale $M_W$.
This is most likely to happen if the running mass-squared in a ``flat''
direction in field space becomes negative at some scale $Q_0$ which is well
below the GUT scale. In this case, either this pattern of masses is ruled out,
or there must be new physics (beyond the MSSM) at or below the scale $Q_0$.


title:
Lepton-Flavor Violation via Right-Handed Neutrino Yukawa Couplings in
  Supersymmetric Standard Model

abstract:
  Various lepton-flavor violating (LFV) processes in the supersymmetric
standard model with right-handed neutrino supermultiplets are investigated in
detail. It is shown that large LFV rates are obtained when $\tan \beta $ is
large. In the case where the mixing matrix in the lepton sector has a similar
structure as the Kobayashi-Maskawa matrix and the third-generation Yukawa
coupling is as large as that of the top quark, the branching ratios can be as
large as $Br(\mu\rightarrow e\gamma)\simeq 10^{-11}$ and
$Br(\tau\rightarrow\mu\gamma)\simeq 10^{-7}$, which are within the reach of
future experiments. If we assume a large mixing angle solution to the
atmospheric neutrino problem, rate for the process $\tau\rightarrow\mu\gamma$
becomes larger. We also discuss the difference between our case and the case of
the minimal $SU(5)$ grand unified theory.


title: Numerical Study of Induced False Vacuum Decay at High Energies

abstract:
  We calculate numerically the probability $\exp[ {1\over\lambda}
F(E/E_{sph},N/N_{sph})]$ of the false vacuum decay in the massive
four-dimensional $-\lambda\phi^4$ model from multiparticle initial states with
fixed number of particles $N$ and energy $E$ greater than the height of the
barrier $E_{sph}$. We find that at $E\lsim 3E_{sph}$ and $N\lsim 0.4N_{sph}$
the decay is classically forbidden and thus is exponentially suppressed. We
argue that the classically forbidden region extends at small $N$ at least up to
$E\sim 10 E_{sph}$ and, most likely, to all energies. Our data suggest that the
false vacuum decay induced by two-particle collisions is exponentially
suppressed at all energies.


title: Gauge-independent Thermal $\beta$ Function In Yang-Mills Theory

abstract:
  It is proposed to use the pinch technique (PT) to obtain the
gauge-independent thermal $\beta$ function in a hot Yang-Mills gas.
Calculations of the thermal $\beta$ function are performed at one-loop level in
four different gauges, (i) the background field method with an arbitrary gauge,
(ii) the Feynman gauge, (iii) the Coulomb gauge, and (iv) the temporal axial
gauge, and they yield the same result in all four cases.


title: Maximal neutrino oscillation solution to the solar neutrino problem

abstract:
  We discuss a simple predictive solution to the solar neutrino problem based
on maximal vacuum neutrino oscillations. The solution can be motivated by the
exact parity symmetric model which predicts that the neutrino mass eigenstates
are maximal mixtures of ordinary and mirror weak eigenstates (if neutrinos are
massive). We show that this proposed solution to the solar neutrino problem is
in reasonable agreement with the experiments, and that in the near future this
scheme may be either ruled out or tested more precisely as statistics improve
for the SAGE and GALLEX experiments. Predictions are also given for the
upcoming Superkamiokande, SNO and Borexino experiments.


title: Perturbative QCD study of $B\to D^{(*)}$ decays

abstract:
  We compute various form factors involved in $B\to D^{(*)}$ transitions based
on the perturbative QCD formalism, which includes Sudakov effects from the
resummation of large radiative corrections in a heavy-light system. A
two-parameter model wave function for $D^{(*)}$ mesons is fixed using data of
the nonleptonic decays $B\to D^{(*)}\pi$, from which the ratio of the decay
constants $f_{D^*}/f_D=0.92$ is obtained. We then derive the spectrum of the
semileptonic decay $B\to D^{*}\ell\nu$ in the fast recoil region of the $D^*$
meson, and extract the CKM matrix element $|V_{cb}|=0.043\times(0.12 {\rm
GeV}/f_B)\times(0.14 {\rm GeV}/f_D)$, $f_B$ and $f_D$ being the $B$ and $D$
meson decay constants, respectively. Here we adopt the convention with the pion
decay constant $f_\pi=93$ MeV. With these outcomes, we evaluate the decay rate
of $B\to DD_s$, and estimate the ratio $f_{D_s}/f_D=0.98$ from data.
Contributions of internal $W$-emission and $W$-exchange diagrams are briefly
discussed.


title:
Dispersion relations from the Hard Thermal Loop effective action in a
  magnetic field

abstract:
  Dispersion relations for fermions at high temperature and in a background
magnetic field are calculated in two different ways. First from a
straightforward one-loop calculation where, in the weak field limit, we find an
expression closely related to the standard dispersion relations in the absence
of the magnetic field. Secondly, we derive the dispersion relations directly
from the Hard Thermal Loop effective action, which allows for an exact solution
(i.e. to all orders in the external field), up to the last numerical integrals.


title: Quantum Transport Theory

abstract:
  The problem of thermalization of a quark -- gluon plasma is addressed in the
framework of thermal field theory. Within a simple approximation, the full
quantum relaxation problem is solved and compared to the Boltzmann solution.
Memory effects and a slowdown of the relaxation process are the results, they
can be partially described by using a generalized kinetic equation without
quasi-particle approximation.


title: Stimulated Neutrino Conversion in the CERN Beam

abstract:
  We discuss the possibility of searching for anomalous magnetic transitions of
neutrinos in the CERN beam induced by the absorption or emission of low-energy
photons in a high-quality resonant cavity such as the LEP radio-frequency
cavities. With the attainable sensitivities of the present CERN neutrino
detectors, this experiment would impose strong limits on this transition and on
the radiative decay lifetime of neutrinos with masses in the range of interest
to the resolution of the dark matter solar and atmospheric neutrino puzzles.


title: Transverse spin and transverse momenta in hard scattering processes

abstract:
  Inclusive and semi-inclusive deep inelastic leptoproduction offers
possibilities to study details of the quark and gluon structure of hadrons. In
many of these experiments polarization is an essential ingredient. We also
emphasize the dependence on transverse momenta of the quarks, which leads to
azimuthal asymmetries in the produced hadrons.


title:
How to See the Chiral Structure of QCD Vacuum in Low Energy $\pi-\pi$
  Scattering

abstract:
  Precise measurement of the $\pi\pi$-phase shift $\delta^0_0(E)$ at very low
energies would provide, for the first time, the experimental evidence in favour
of or against the existence of a large quark condensate in the QCD vacuum,
which is standardly postulated as the mechanism of the spontaneous breakdown of
chiral symmetry in QCD. The contribution of Da$\phi$ne to this discovery could
be decisive.


title:
Hyperon production mechanisms and single-spin asymmetry in high energy
  hadron-hadron collisions

abstract:
  It is shown that the existence of left-right asymmetry in single-spin
inclusive Lambda production, together with the characteristic features of the
data, should be considered as another clear signature for the existence of
orbiting valence quarks in polarized nucleons. Predictions for other hyperons
are made. It is pointed out that measurements of such asymmetries are very
helpful not only for probing the spin structure of the nucleons but also for
studying the production mechanisms of the hyperons.


title: New Bounds on R-Parity Violating Couplings

abstract:
  Bounds on R-parity violating couplings in the supersymmetric standard model
are reviewed, and some new bounds arising from non-observation of certain rare
B-decays (such as $B \rightarrow K^+K^-$) are presented. The focus is on
baryon-number violating couplings, but it is also noted that many products of
lepton- number violating and baryon-number violating couplings are not
significantly constrained by proton decay bounds. The talk reviewed the work in
a recent paper by Carlson, Roy and Sher (Phys. Letters, in press).


title: Heavy Quark Fragmentation Functions In The Heavy Quark Effective Theory

abstract:
  We calculate fragmentation functions for a b-quark to fragment into
color-singlet P-wave bound states $\bar c b$ in the Heavy Quark Effective
Theory with the exact account of $O(1/m_b)$ corrections. We demonstrate an
agreement of the obtained results with the corresponding calculations carried
out in quantum chromodynamics.


title: Approximate spectral functions in thermal field theory

abstract:
  Causality requires, that the (anti-) commutator of two interacting field
operators vanishes for space-like coordinate differences. This implies, that
the Fourier transform of the spectral function of this quantum field should
vanish in the space-like domain. We find, that this requirement imposes some
constraints on the use of resummed propagators in high temperature gauge
theory.


title:
Indirect CP-Violation in the Neutral Kaon System Beyond Leading
  Logarithms and Related Topics

abstract:
  I describe in detail the calculation of the coefficients eta_3 and eta_1 of
the low-energy Delta S=2 -hamiltonian describing K^0-K^0-bar-mixing in the
next-to-leading order of renormalization group improved (RG) perturbation
theory. First a general introduction into the application of the operator
expansion and of RG methods to weak processes is presented. This includes the
RG formalism for Green's functions with two operator insertions. Second I
discuss the elimination of unphysical operators with emphasis on evanescent
operators. Then the two-loop calculations needed for eta_3 and eta_1 are shown
and finally the implications on the phenomenology of epsilon_K and the K_L-K_S
mass difference are discussed. The results of this thesis have been published
separately, but they are explained in more detail here.


title:
Measurement of the $WW\gamma$ and $WWZ$ Couplings at LEP200: The
  Benefits of Higher Energy?

abstract:
  We performed a detailed analysis of the process $e^+e^-\to \ell \nu
q\bar{q}'$ to determine its sensitivity to anomalous trilinear gauge boson
couplings of the $WW\gamma$ and $WWZ$ vertices and how the sensitivity varies
with energy and integrated luminosity. We included all tree level Feynman
diagrams that contribute to this final state and used a maximum likelihood
analysis of a five dimensional differential cross-section based on the $W$ and
$W$ decay product angular distributions. For constant luminosity, increasing
$\sqrt{s}$ from 175~GeV to 192~GeV (220~GeV) improves the measurement
sensitivity by a factor of 1.5 to 2 (2 to 3) depending on the parameter
measured. However, the lower luminosity expected at higher $\sqrt{s}$ will
reduce these improvements. In any case, the sensitivities for
$\sqrt{s}$=175~GeV and L=500~pb$^{-1}$ of $\delta g_1^Z = \pm 0.22$, $\delta
\kappa_Z = \pm 0.20$, $\delta\kappa_\gamma=\pm 0.27$, $\delta L_{9L}= \pm 55$,
and $\delta L_{9R}= ^{+330}_{-230}$ are likely to be at least an order of
magnitude too big to see the effects of new physics.


title: Inclusive $B_c$ Decays As A QCD Lab

abstract:
  Phenomenological models of heavy flavour decays differ significantly in their
predictions of global features of $B_c$ decays, like the $B_c$ lifetime or the
relative weight of $c\ra s$ and $b\ra c$ transitions. The $1/m_Q$ expansion
which is directly based on QCD allows predictions on the pattern to be
expected, namely $\tau (B_c)$ to lie well below 1 psec with $c\ra s$ dominating
over $b\ra c$ and a reduced semileptonic branching ratio. Due to interference
effects one also predicts a lower charm content in the final states of $B_c$
decays than naively anticipated. The numerical aspect of the predictions,
however, has to be viewed with considerable caution since one cannot expect the
$1/m_c$ expansion to converge readily for $\Delta C=1$ transitions.


title: Heavy Hadrons and QCD Instantons

abstract:
  Heavy hadrons are analyzed in a random and dilute gas of instantons. We
derive the instanton-induced interactions between heavy and light quarks at
next to leading order in the heavy quark mass and in the planar approximation,
and discuss their effects on the hadronic spectrum. The role of these
interactions in the formation of exotic hadrons is also discussed.


title: Viable $t$-$b$-$\tau$ Yukawa Unification in SUSY SO(10)

abstract:
  The supersymmetric SO(10) GUT with $t$--$b$--$\tau$ Yukawa coupling
unification has problems with correct electroweak symmetry breaking,
experimental constraints (especially $b\rightarrow s\gamma$) and neutralino
abundance, if the scalar masses are universal at the GUT scale. We point out
that non-universality of the scalar masses at the GUT scale generated both by
(1) renormalization group running from the Planck scale to the GUT scale and
(2) $D$--term contribution induced by the reduction of the rank of the gauge
group, has a desirable pattern to make the model phemenologically viable (in
fact the only one which is consistent with experimental and cosmological
constraints). At the same time the top quark mass has to be either close to its
quasi IR--fixed point value or below $\sim$170 GeV. We also briefly discuss the
spectrum of superpartners which is then obtained.


title: Lattice Chiral Gauge Theory with Finely-Grained Fermions

abstract:
  We discuss the problem of formulating the continuum limit of chiral gauge
theories ($\chi$GT) in the absence of an explicitly gauge-invariant regulator
for the fermions. A solution is proposed which is independent of the details of
the regulator, wherein one considers two cutoff scales, $\Lambda_f >>
\Lambda_b$, for the fermions and the gauge bosons respectively. Our recent
non-perturbative lattice construction in which the fermions live on a finer
lattice than do the gauge bosons, is seen to be an example of such a scheme,
providing a finite algorithm for simulating $\chi$GT. The essential difference
with previous (one-cutoff) lattice schemes is clarified: in our formulation the
breakage of gauge invariance is small, $O(\Lambda^2_b/\Lambda^2_f)$, and
vanishes in the continuum limit. Finally, we argue against 2-D models being
significant testing grounds for 4-D regulators of $\chi$GT.


title: Gauge Theory High-Energy Behavior from J-Plane Unitarity

abstract:
  In a non-abelian gauge theory the $t$-channel multiparticle unitarity
equations continued in the complex j-plane can be systematically expanded
around $j=1$. The combination of Ward identity constraints with unitarity is
sufficient to produce directly many results obtained by Regge limit leading-log
and next-to-leading log momentum space calculations. The $O(g^2)$ BFKL kernel
is completely determined. $O(g^4)$ contributions to the kernel are also
determined, including the leading contribution of a new partial-wave amplitude
- previously identified as a separate forward component with a holomorphically
factorizable spectrum. For this amplitude the only scale ambiguity is the
overall normalization and it is anticipated to be a new conformally invariant
kernel. The results suggest that all conformally invariant reggeon interactions
are determined by $t$-channel unitarity.