title: A New Paradigm for the Fermion Generations

abstract:
  A new mechanism is proposed to explain the appearance of the three known
fermion generations in a natural way. The underlying idea is based on the
discreteness of the spectrum of solutions of the gap equation appearing in
models of dynamical chiral symmetry breaking. Within such a framework, the
number of parameters needed to describe the experimentally observed fermion
spectrum is drastically reduced. The phenomenological consequences of such a
mechanism are carefully discussed, in order to explore its viability.


title: Does the effective Lagrangian for low-energy QCD scale?

abstract:
  QCD is not an approximately scale invariant theory. Hence a dilaton field is
not expected to provide a good description of the low-energy dynamics
associated with the gluon condensate. Even if such a field is introduced, it
remains almost unchanged in hadronic matter at normal densities. This is
because the large glueball mass together with the size of the phenomenological
gluon condensate ensure that changes to that condensate are very small at such
densities. Any changes in hadronic masses and decay constants in matter
generated by that condensate will be much smaller that those produced directly
by changes in the quark condensate. Hence masses and decay constants are not
expected to display a universal scaling.


title:
Exact Construction of the Electromagnetic Current Operator for
  Relativistic Composite Systems

abstract:
  The electromagnetic current operator of a composite system must be a
relativistic vector operator satisfying current conservation, cluster
separability and the condition that interactions between the constituents do
not renormalize the total electric charge. Assuming that these interactions are
described in the framework of relativistic quantum mechanics of systems with a
fixed number of particles we explicitly construct the current operators
satisfying the above properties in cases of two and three particles and prove
that solutions exist for any number of particles. The consideration is
essentially based on the method of packing operators in the point form of
relativistic dynamics developed by Sokolov. Using the method developed by
Sokolov and Shatny we also construct the current operators in the instant and
front forms and prove that the corresponding results are physically equivalent.
The paper is self-contained what makes it possible for the reader to learn
both, relativistic quantum mechanics of systems with a fixed number of
particles and the problem of constructing the electromagnetic current operator
for such systems.


title:
Charge symmetry breaking via rho-omega mixing from model quark-gluon
  dynamics

abstract:
  The quark-loop contribution to the $\rho^0-\omega$ mixing self-energy
function is calculated using a phenomenologically successful QCD-based model
field theory in which the $\rho^0$ and $\omega$ mesons are composite $\bar{q}q$
bound states. In this calculation the dressed quark propagator, obtained from a
model Dyson-Schwinger equation, is confining. In contrast to previous studies,
the meson-$\bar{q}q$ vertex functions are characterised by a strength and range
determined by the dynamics of the model; and the calculated off-mass-shell
behaviour of the mixing amplitude includes the contribution from the calculated
diagonal meson self-energies. The mixing amplitude is shown to be very
sensitive to the small isovector component of dynamical chiral symmetry
breaking. The spacelike quark-loop mixing-amplitude generates an insignificant
charge symmetry breaking nuclear force.


title: Dyson-Schwinger Equations and the Application to Hadronic Physics

abstract:
  We review the current status of nonperturbative studies of gauge field theory
using the Dyson-Schwinger equation formalism and its application to hadronic
physics. We begin with an introduction to the formalism and a discussion of
renormalisation in this approach. We then review the current status of studies
of Abelian gauge theories [e.g., strong coupling quantum electrodynamics]
before turning our attention to the non-Abelian gauge theory of the strong
interaction, quantum chromodynamics. We discuss confinement, dynamical chiral
symmetry breaking and the application and contribution of these techniques to
our understanding of the strong interactions.


title: QSSR estimate of the $B_B$ parameter at next-to-leading order

abstract:
  We compute the leading $\alpha_s$ corrections to the two-point correlator of
the $O_{\Delta B=2}$ operator which controls the $B^0 \bar B^0$ mixing. Using
this result within the QCD spectral sum rules approach and some
phenomenologically reasonable assumptions in the parametrization of the
spectral function, we conclude that the vacuum saturation values $B_B\simeq
B_{B^*}\simeq 1$ are satisfied within 15\%.


title: One-Loop n-Point Gauge Theory Amplitudes, Unitarity and Collinear Limits

abstract:
  We present a technique which utilizes unitarity and collinear limits to
construct ansatze for one-loop amplitudes in gauge theory. As an example, we
obtain the one-loop contribution to amplitudes for $n$ gluon scattering in
$N=4$ supersymmetric Yang-Mills theory with the helicity configuration of the
Parke-Taylor tree amplitudes. We prove that our $N=4$ ansatz is correct using
general properties of the relevant one-loop $n$-point integrals. We also give
the ``splitting amplitudes'' which govern the collinear behavior of one-loop
helicity amplitudes in gauge theories.


title: Intrinsic transverse momentum and the polarized Drell-Yan process

abstract:
  In this paper we study the cross section at leading order in $1/Q$ for
polarized Drell-Yan scattering at measured lepton-pair transverse momentum
$Q_T$. We find that for a hadron with spin $1/2$ the quark content at leading
order is described by six distribution functions for each flavor, which depend
on both the lightcone momentum fraction $x$, and the quark transverse momentum
$\bbox{k}_T^2$. These functions are illustrated for a free-quark ensemble. The
cross sections for both longitudinal and transverse polarizations are expressed
in terms of convolution integrals over the distribution functions.


title: Anomalous Thresholds and the Isgur-Wise Function

abstract:
  The original de Rafael-Taron bound on the slope of the Isgur-Wise function at
zero recoil is known to be violated in QCD by singularities appearing in an
unphysical region. To be consistent, quark models must have corresponding
singularity structures. In an existing relativistic quark-loop model, the
meson-quark-antiquark vertex is such that the required singularity is an
anomalous threshold. We also discuss the implications of another anomalous
threshold, whose location is determined by quark masses alone.


title:
Virtual Photon Strucutre Functions and the Parton Content of the
  Electron

abstract:
  We point out that in processes involving the parton content of the photon the
usual effective photon approximation should be modified. The reason is that the
parton content of virtual photons is logarithmically suppressed compared to
real photons. We describe this suppression using several simple, physically
motivated ans\"atze. Although the parton content of the electron in general no
longer factorizes into an electron flux function and a photon structure
function, it can still be expressed as a single integral. Numerical examples
are given for the \eplem\ collider TRISTAN as well as the $ep$ collider HERA.


title: Calculation of Feynman Diagrams from their Small Momentum Expansion

abstract:
  A new powerful method to calculate Feynman diagrams is proposed. It consists
in setting up a Taylor series expansion in the external momenta squared (in
general multivariable). The Taylor coefficients are obtained from the original
diagram by differentiation and putting the external momenta equal to zero,
which means a great simplification. It is demonstrated that it is possible to
obtain by analytic continuation of the original series high precision numerical
values of the Feynman integrals in the whole cut plane. For this purpose
conformal mapping and subsequent resummation by means of Pad\'{e} approximants
or Levin transformation are applied.


title:
The Renormalization of Composite Operators in Yang-Mills Theories Using
  General Covariant Gauge

abstract:
  Essential to QCD applications of the operator product expansion, etc., is a
knowledge of those operators that mix with gauge-invariant operators. A
standard theorem asserts that the renormalization matrix is triangular:
Gauge-invariant operators have `alien' gauge-variant operators among their
counterterms, but, with a suitably chosen basis, the necessary alien operators
have only themselves as counterterms. Moreover, the alien operators are
supposed to vanish in physical matrix elements. A recent calculation by Hamberg
and van Neerven apparently contradicts these results. By explicit calculations
with the energy-momentum tensor, we show that the problems arise because of
subtle infra-red singularities that appear when gluonic matrix elements are
taken on-shell at zero momentum transfer.
  Keywords: twist-two covariant gluon operator, finite part, mixing,
non-abelian, anomalous dimension, Ward identity, BRST, modified LSZ reduction,
Dixon, Taylor, Joglekar, Lee.


title:
The two-fermion relativistic wave equations of Constraint Theory in the
  Pauli-Schr\"odinger form

abstract:
  The two-fermion relativistic wave equations of Constraint Theory are reduced,
after expressing the components of the $4\times 4$ matrix wave function in
terms of one of the $2\times 2$ components, to a single equation of the
Pauli-Schr\"odinger type, valid for all sectors of quantum numbers. The
potentials that are present belong to the general classes of scalar,
pseudoscalar and vector interactions and are calculable in perturbation theory
from Feynman diagrams. In the limit when one of the masses becomes infinite,
the equation reduces to the two-component form of the one-particle Dirac
equation with external static potentials. The Hamiltonian, to order $1/c^2$,
reproduces most of the known theoretical results obtained by other methods. The
gauge invariance of the wave equation is checked, to that order, in the case of
QED. The role of the c.m. energy dependence of the relativistic interquark
confining potential is emphasized and the structure of the Hamiltonian, to
order $1/c^2$, corresponding to confining scalar potentials, is displayed.


title: Two- and Three-Point Functions in the Extended NJL Model

abstract:
  The two-point functions in generalized Nambu--Jona-Lasinio models are
calculated to all orders in momenta and quark masses to leading order in
$1/N_c$. The use of Ward identities and the heat-kernel expansion allows for a
large degree of regularization independence. We also show how this approach
works to the same order for three-point functions on the example of the
vector-pseudoscalar-pseudoscalar three-point function. The inclusion of the
chiral anomaly effects at this level is shown by calculating the
pseudoscalar-vector-vector three-point function to the same order. Finally we
comment on how (vector-)meson-dominance comes out in the presence of explicit
chiral symmetry breaking in both the anomalous and the non-anomalous sectors.


title:
How to Parametrize an S-Wave Resonance and How to Identify Two-Hadron
  Composites

abstract:
  The question of how one can distinguish quark model states from 2-hadron
states near an S-wave theshold is discussed, and the usefulness of the running
mass is emphasized as the meeting ground for experiment and theory and for
defining resonance parameters.


title: Strong rescattering in K-> 3pi decays and low-energy meson dynamics

abstract:
  We present a consistent analysis of final state interactions in
${K\rightarrow 3\pi}$ decays in the framework of Chiral Perturbation Theory.
The result is that the kinematical dependence of the rescattering phases cannot
be neglected. The possibility of extracting the phase shifts from future
$K_S-K_L$ interference experiments is also analyzed.


title: Leptoproduction of charm revisited

abstract:
  We calculate the energy--momentum distribution of the charmed quarks produced
in neutrino reactions on protons, quantifying the importance of mass and
current non--conservation effects. We study the strange and charm distributions
probed in neutrino interactions in the presently accessible kinematical region.
Some ambiguities inherent to the extraction of the parton densities from dimuon
data are pointed out.


title:
Single Dilepton Production at $e^+e^-$, $e\gamma$ and $\gamma\gamma$
  Colliders

abstract:
  We calculate the cross sections for the single production of doubly-charged
dileptons, both scalar and vector, at $e^+e^-$, $e\gamma$ and $\gamma\gamma$
colliders at $\sqrt{s}=500$ GeV and 1 TeV. The $e\gamma$ mode is by far the
most promising -- dileptons whose coupling is as weak as
$O(10^{-4})\alpha_{em}$ can be observed, for masses virtually up to the
kinematic limit. Dileptons of mass up to $\sqrt{s}$ can also be seen in
$e^+e^-$ and $\gamma\gamma$ colliders, for couplings of order $\alpha_{em}$. In
all three colliders, most of the cross section comes from events in which the
only particles detected are $e^-e^-$, the decay products of the dilepton,
yielding an unmistakeable experimental signature.


title: Radiative Correction Schemes in Deep Inelastic Muon Scattering

abstract:
  A description and a detailed comparison of the Mo and Tsai and the Dubna
radiative correction schemes is presented. Numerical comparisons made in the
kinematical region of the NMC high energy deep inelastic electroproduction
experiment are discussed. An overall agreement between the two approaches in
the region of low $x$ and high $y$, where the radiative corrections are
largest, is better than 2$\%$.


title: Gamma ray lines from TeV dark matter

abstract:
  We calculate, using unitarity, a lower bound on the branching ratio
$\chi\chi\to \gamma\gamma$ and $\chi\chi\to \gamma Z$, where $\chi$ is any halo
dark matter particle that has $W^+W^-$ as one of the major annihilation modes.
Examples of such particles are supersymmetric particles with a dominant
Higgsino component, or heavy triplet neutrinos. A substantial branching ratio
is found for the $\gamma\gamma$ and $\gamma Z$ modes. We estimate the strength
of the monoenergetic $\gamma$ ray lines that result from such annihilations in
the Galactic or LMC halos. (Latex file; 2 compressed uuencoded postscript
figures available by anonymous ftp from vanosf.physto.se in file
pub/figures/lines.uu)


title:
The complete radiative corrections to the gaugino and Higgsino masses in
  the Minimal Supersymmetric Model

abstract:
  We determine the radiative corrections to the masses of the gauginos and
Higgsinos in the MSSM, including all sectors of the theory in a one-loop
calculation in the on-mass-shell renormalization scheme. We find that a gluino
which is massless at tree level receives a mass of between 0 and 3 GeV,
primarily due to the top/stop contribution. This radiatively generated mass
depends directly on the off-diagonal element of the squark mass matrix. In the
case of a massive gluino, its mass receives typically large corrections, as
large as 40\% for a 125 GeV gluino. We find that the contributions to the
neutralino and chargino mass corrections from the gauge/Higgs/gaugino/Higgsino
sector are typically +-1%. The lightest neutralino, which can receive
corrections larger than 25%, receives 5% corrections over most of the parameter
space. We combine our results with the results of LEP and CDF searches to
obtain the lower bounds on the neutralino and chargino masses at one-loop. We
also demonstrate how the radiative corrections affect the presently excluded
region of parameter space.


title: $A_{LR}$, Negative $S$, and Extended Gauge Models

abstract:
  The implications of the recent measurement of the left-right asymmetry,
$A_{LR}$, by the SLD Collaboration for theories with extended gauge sectors is
examined. We show that it is possible to arrange for large, negative values of
$S$, based on an analysis of leptonic data, without serious side effects for
other observables in certain classes of models. The implications of such
scenarios for future measurements on the $Z$ peak, at the Tevatron, and for
atomic parity violation experiments are examined.


title: How to measure the intercept of the BFKL pomeron at HERA

abstract:
  Determination of the intercept of the BFKL pomeron is one of the pressing
issues in the high energy physics. Earlier we have shown that, at the dipole
size $r=r_{\Delta}=(0.1-0.2)$f, the dipole cross section $\sigma(x,r)$ which is
a solution of the generalized BFKL equation, exhibits a precocious asymptotic
behavior $\sigma(x,r)\propto \left({1\over x}\right)^{\Delta_{\Pom}}$. In this
paper we discuss how measuring $F_{L}(x,Q^{2})$ and $\partial
F_{T}(x,Q^{2})/\partial \log Q^{2}$ at $Q^{2}= (10-40)$GeV$^{2}$ and
$Q^{2}=(2-10)$GeV$^{2}$, respectively, one can probe $\sigma(x,r_{\Delta})$ and
directly determine the intercept $\Delta_{\Pom}$ of the BFKL pomeron in the
HERA experiments.


title: On determination of the large-${1\over x}$ gluon distribution at HERA

abstract:
  We discuss corrections to the Leading-Log$Q^{2}$ relationships between the
gluon density $g(x,Q^{2})$ and $F_{L}(x,Q^{2}),\,\partial F_{T}(x,Q^{2})
/\partial \log Q^{2}$ in the HERA range of large ${1\over x}$. We find that the
above quantities probe the gluon density $g(x,Q_{T,L}^{2})$ at
$Q_{T,L}^{2}=C_{T,L}Q^{2}$, with the $Q^{2}$-rescaling factors $C_{T}\approx
2.2$ and $C_{L}\approx 0.42$. The possibility of treating charm as an active
flavour is critically re-examined.


title: A New Method for Helicity Calculations

abstract:
  We propose a new helicity formalism based on the formal insertion in spinor
lines of a complete set of states build up with unphysical spinors. The method
is developed both for massless and massive fermions for which it turns out to
be particularly fast. All relevant formulae are given.


title:
Scaling Laws in Hierarchical Clustering Models with Poisson
  Superposition

abstract:
  Properties of cumulant- and combinant ratios are studied for multihadron
final states composed of Poisson distributed clusters. The application of these
quantities to ``detect'' clusters is discussed. For the scaling laws which hold
in hierarchical clustering models (void scaling, combinant scaling) a
generalization is provided. It is shown that testing hierarchical models is
meaningful only for phase-space volumes not larger than the characteristic
correlation length introduced by Poisson superposition. Violation of the
scaling laws due to QCD effects is predicted.


title: Top quark polarization as a probe of $t\bar{t}$ threshold dynamics

abstract:
  We study the spin properties of top quarks produced in collisions of
polarized photons in the threshold region. For a relatively heavy top quark the
influence of non-perturbative effects is small and its polarization parameters
can be predicted in perturbative QCD. The measurements of the top polarization
may allow a novel test of QCD in the $t\bar{t}$ system. In particular, they may
provide a new way to determine the precise value of $\alpha_s$ and to study the
properties of the top quark.


title: Dynamical Generation of Mass

abstract:
  An alternative for the Higgs mechanism is proposed. It predicts the
appearance in the broken phase of a scalar background field which may be
interpreted as describing an almost uniform (i.e., homogeneous and isotropic)
superfluid condensate of decoupled Higgs bosons. Quantum fields acquire mass as
a consequence of nonperturbative interactions with those particles condensed in
the zero-momentum state (which constitutes the physical vacuum of the theory)
giving rise in turn to the appearance of density fluctuations. This mechanism
has therefore remarkable cosmological implications.


title: Amplitude Zeros in $W^\pm Z$ Production

abstract:
  We demonstrate that the Standard Model amplitude for $f_1 \bar f_2
\rightarrow W^\pm Z $ at the Born-level exhibits an approximate zero located at
$\cos\theta = (g^{f_1}_{-} + g^{f_2}_{-}) / (g^{f_1}_{-} - g^{f_2}_{-})$ at
high energies, where the $g^{f_i}_{-}$ ($i=1,2$) are the left-handed couplings
of the $Z$-boson to fermions and $\theta$ is the center of mass scattering
angle of the $W$-boson. The approximate zero is the combined result of an exact
zero in the dominant helicity amplitudes ${\cal M}(\pm,\mp)$ and strong gauge
cancelations in the remaining amplitudes. For non-standard $WWZ$ couplings
these cancelations no longer occur and the approximate amplitude zero is
eliminated.


title: Higher Order $1/m$ Corrections at Zero Recoil

abstract:
  The general structure of the $1/m$ corrections at zero recoil is studied. The
relevant matrix elements are forward matrix elements of local higher
dimensional operators and their time ordered products with higher order terms
from the Lagrangian. These matrix elements may be classified in a simple way
and the analysis at the non recoil point for the form factor of heavy quark
currents simplifies drastically. The second order recoil corrections to the
form factor $h_{A1}$ of the axial vector current, relevant for the $|V_{cb}|$
determination from $B \to D^*$ decays, are estimated to be $-5\% < h_{A1} - 1 <
0$.


title: Two-loop next-to-leading $\mt$ corrections to the $\rho$ parameter

abstract:
  The $O(G^2_\mu m_t^4)$ correction to the $\rho$ parameter is computed within
the Standard Model using the current algebra formulation of radiative
corrections. This approach is proved to be equivalent to the effective
Lagrangian method proposed by Barbieri {\em et al.} Using the same framework,
the $O(G^2_\mu m_t^2 m_z^2)$ correction to the ratio of neutral-to-charged
current amplitudes is analysed in an $SU(2)$ model. The $O(G^2_\mu m_t^2
m_z^2)$ contribution is shown to be numerically comparable to the leading
$O(G^2_\mu m_t^4)$ term for realistic values of the top mass. The resummation
of higher-order effects is discussed.


title: Anomalous Evolution of Nonsinglet Nucleon Structure Functions

abstract:
  We calculate the scale dependence of nonsinglet nucleon structure functions.
Due to anomalous axial symmetry breaking a large flavour asymmetry of the
quark--antiquark sea is generated nonperturbatively. This produces a strong
scale dependence of the nonsinglet structure function in an intermediate range
of $Q^2$. Evolving nonperturbatively a pure valence distribution from an
infrared scale we can thus compute $F_2^p-F_2^n$ as measured by the NMC, and
give detailed predictions for its $Q^2$ dependence at fixed $x$. We also
compare our results with Drell--Yan data.


title:
Gauge covariant fermion propagator in quenched, chirally-symmetric
  quantum electrodynamics

abstract:
  We discuss the chirally symmetric solution of the massless, quenched,
Dyson-Schwinger equation for the fermion propagator in three and four
dimensions. The solutions are manifestly gauge covariant. We consider a gauge
covariance constraint on the fermion--gauge-boson vertex, which motivates a
vertex Ansatz that both satisfies the Ward identity when the fermion self-mass
is zero and ensures gauge covariance of the fermion propagator.


title:
Upsilon \bar BB$ Couplings, Slope of the Isgur-Wise Function and
  Improved Estimate of \boldmath{$V_{cb}$}}

abstract:
  We estimate the sum of the $\Upsilon \bar BB $ couplings using QCD Spectral
Sum Rules (QSSR). Our result implies the phenomenological bound $\xi'(vv'=1)
\geq -1.04$ for the slope of the Isgur-Wise function. An analytic estimate of
the (physical) slope to two loops within QSSR leads to the accurate value
$\xi'(vv'=1) \simeq -(1.00 \pm 0.02)$ due to the (almost) complete
cancellations between the perturbative and non-perturbative corrections at the
stability points. Then, we deduce, from the present data, the improved estimate
$\vert V_{cb} \vert \simeq \ga 1.48 \mbox{ps}/\tau_B \dr ^{1/2}(37.3 \pm 1.2
\pm 1.4)\times 10^{-3}$ where the first error comes from the data analysis and
the second one from the different model parametrizations of the Isgur-Wise
function.


title:
Precise Determination of {$f_{P_{s}}/f_P$}} {\bf and Measurement of the
  ``Perturbative'' Pole Mass from {$f_P$}}

abstract:
  We present a compact analytic two-loop expression of the $SU(3)_f$ breaking
effects on the ratio of the pseudoscalar decay constants $R_P \equiv
f_{P_S}/f_P$ ($P \equiv D,B $), from which, we extract the precise values :
$R_D = 1.15 \pm .04$, $R_B = 1.16 \pm .05 $, where the errors are mainly due to
the uncalculated $\alpha_s^2$-corrections. We also scan carefully the $M_c$
(resp. $M_b$) mass dependence of $f_D$ (resp. $f_B$) in view of precise
measurements of the ``perturbative'' c and b pole quark masses from the future
data of the decay constants $f_P$.


title: Isospin Analysis of Two-body B Decays and Test of Factorization

abstract:
  It is shown that the existing data on two-body B decays, some of them only
upper limits, are precise enough to perform an isospin analysis to extract the
phase shifts due to final state interaction. Unlike charm decays, no
significant final state interaction is observed in decays $B\to D\pi, D\rho$,
and $D^*\pi$ supporting the factorization hypothesis in these decays. By
fitting directly the isospin amplitudes obtained, we extract the ratio
$a_2/a_1$, where $a_1$ and $a_2$ are the coefficients in the factorized
effective Hamiltonian.


title:
Single and Double BFKL Pomeron Exchange and a Dipole Picture of High
  Energy Hard Processes

abstract:
  Onium-onium scattering at high energy is used to illustrate a dipole picture
of high energy hard scattering in the large $N_c$ limit. Single and double BFKL
pomeron exchanges are calculated in the leading logarithmic approximation. An
expression is given for the triple pomeron coupling when one of the pomeron's
momentum is zero while the other two have momentum transfer, t. This expression
is explicit and could be evaluated numerically. It has a $(-t)^{-{1\over 2}}$
singularity at t=0.


title: Violation of CPT and Quantum Mechanics in the K0--K0bar System

abstract:
  We reconsider the model of quantum mechanics violation in the $\ko$--$\kob$
system, due to Ellis, Hagelin, Nanopoulos, and Srednicki, in which \cp- and
\cpt-violating signatures arise from the evolution of pure states into mixed
states. We present a formalism for computing time-dependent asymmetries in this
model and show that present data constrains its parameters significantly. In
the future, this model will be put to very stringent tests at a $\phi$ factory.
We present the theory of these tests and show the relation between particular
$\phi$ decay correlations and the parameters of quantum mechanics violation.


title:
A Constituent Quark Anti-Quark Effective Lagrangian Based on the Dual
  Superconducting Model of Long Distance QCD

abstract:
  We review the assumptions leading to the description of long distance QCD by
a Lagrangian density expressed in terms of dual potentials. We find the color
field distribution surrounding a quark anti-quark pair to first order in their
velocities. Using these distributions we eliminate the dual potentials from the
Lagrangian density and obtain an effective interaction Lagrangian $L_I ( \vec
x_1 \, , \vec x_2 \, ; \vec v_1 \, , \vec v_2 )$ depending only upon the quark
and anti-quark coordinates and velocities, valid to second order in their
velocities. We propose $L_I$ as the Lagrangian describing the long distance
interaction between constituent quarks. Elsewhere we have determined the two
free parameters in $L_I$, $\alpha_s$ and the string tension $\sigma$, by
fitting the 17 known levels of $b \bar b$ and $c \bar c$ systems. Here we use
$L_I$ at the classical level to calculate the leading Regge trajectory. We
obtain a trajectory which becomes linear at large $M^2$ with a slope $\alpha'
\simeq .74 \, \hbox{GeV}^{-1}$, and for small $M^2$ the trajectory bends so
that there are no tachyons. For a constituent quark mass between 100 and 150
MeV this trajectory passes through the two known Regge recurrences of the $\pi$
meson. In this paper, for simplicity of presentation, we have treated the
quarks as spin-zero particles.


title: On Preserving a B+L Asymmetry Produced in the Early Universe

abstract:
  One of the most efficient mechanisms for producing the baryon asymmetry of
the Universe is the decay of scalar condensates in a SUSY GUT as was first
suggested by Affleck and Dine. We show that given a large enough asymmetry, the
baryon number will be preserved down to low temperatures even if B - L = 0,
because the baryon number carrying scalars form bose condensates that give the
W a mass. We derive the conditions on the condensate needed to suppress
electroweak sphaleron interactions which would otherwise drive the baryon
asymmetry to zero when B - L = 0.


title: $Q^2$-Dependence of Deep Inelastic Sum Rules

abstract:
  In this talk, I will concentrate on $Q^2$-dependence of deep inelastic sum
rules. I will first give a modern definition of deep-inelastic sum rules and
then discuss physical origins of their scaling violation at finite $Q^2$.
Following this, I discuss a few well-known examples, in particular, the Bjorken
sum rule, which is at the center of interest of this symposium. Finally, I
consider the $Q^2 \to 0$ limit of sum rules using low-energy theorems. I think
this can motivate some interesting CEBAF physics.


title: Pion Form Factor: Transition From Soft To Hard QCD

abstract:
  We have reexamined the elastic pion form factor over a broad range of
momentum transfers with the mass evolution from current quark to constituent
quark being taken into account. We have also studied the effect of Sudakov form
factors, of anomalous quark magnetic moments and of alternative soft wave
functions. Our calculation shows a power-law falloff from the present
experimental values to near-asymptotic values in the few $GeV^{2}$ range.


title:
Instanton -- Antiinstanton interaction and asymptotics of perturbation
  theory expansion in double well oscillator

abstract:
  Instanton -- antiinstanton pair is considered as a source of singularity at
the Borel plane for the ground state energy of anharmonic oscillator. The
problem of defining the short range instanton -- antiinstanton interaction
reduces to calculation of a smooth part of the Borel function, which cannot be
found without explicit calculation of several terms of ordinary perturbation
theory. On the other hand, the large order terms of perturbative expansion are
dominated by large fluctuations in the functional integral like well separated
instanton and antiinstanton.
  The preasymptotics ($\sim 1/n$) of large order perturbation theory
contribution to the ground state energy of anharmonic oscillator was found
analytically. To this end the subleading long range asymptotics of the
classical instanton -- antiinstanton interaction, the one -- loop quantum
contribution to instanton -- antiinstanton interaction and the second quantum
correction to a single instanton density were considered.


title: Light Quark Masses and Mixing Angles

abstract:
  I review the present state of our knowledge about the masses and weak mixing
elements of the u, d, s quarks. This is the written version of lectures given
in the 1993 Theoretical Advanced Study Institute (TASI).


title: Relativistic Effects in the Scalar Meson Dynamics

abstract:
  A separable potential formalism is used to describe the $\pi\pi$ and
$K\overline{K}$ interactions in the scalar-isoscalar states in the energy range
from the $\pi\pi$ threshold up to 1.4 GeV. Introduction of relativistic
propagators into a system of Lippmann-Schwinger equations leads to a very good
description of the data ($\chi^{2}=0.93$ per one degree of freedom). Three
poles are found in this energy region: fo(500) ($M=506\pm 10$ MeV,
$\Gamma=494\pm 5$ MeV), fo(975) ($M=973\pm 2$ MeV, $\Gamma=29\pm 2$ MeV) and
fo(1400) ($M=1430\pm 5$ MeV, $\Gamma=145\pm 25$ MeV). The fo(975) state can be
interpreted as a $K\overline{K}$ bound state. The fo(500) state may be
associated with the often postulated very broad scalar resonance under the
$K\overline{K}$ threshold (sometimes called $\sigma$ or $\epsilon$ meson). The
scattering lengths in the $\pi\pi$ and $K\overline{K}$ channels have also been
obtained. The relativistic approach provides qualitatively new results (e.g.
the appearance of the fo(500)) in comparison with previously used
nonrelativistic approach.


title: J-Psi Suppression in Hadron-Nucleus Collisions

abstract:
  We examine the production of J/$\Psi$ mesons in high energy hadron-nucleus
collisions using models that account for both the initial state modification of
parton distributions in nuclei and the final state interaction of the produced
$c\bar c$ pairs. We show that, at the energies of current fixed target
experiments, J/$\Psi$ production through quark-antiquark annihilation gives the
largest contribution at $x_F > 0.5$, while gluon-gluon fusion dominates the
production at smaller $x_F$. The observed J/$\Psi$ suppression at large $x_F$
is directly connected to nuclear shadowing in deeply inelastic scattering. We
find that a $6\sim 8$mb $c\bar c$-nucleon cross section is needed to explain
the data on J/$\Psi$ suppression if a simple incoherent multiple scattering
formalism is used for the final state interactions.


title:
Hadronic Penguin B Decays In The Standard And The Two-Higgs-Doublet
  Models

abstract:
  We study in next-to-leading order QCD hadronic penguin $B$ decays in the
Standard and two-Higgs-doublet models. Although the gluonic penguin dominates,
we find the electroweak contribution non-negligible. In the Standard Model, the
branching ratio for $B \rightarrow X_s \phi$ is predicted to be in the range
$(0.6\sim 2)\times 10^{-4}$. The ranges of branching ratios for $B\rightarrow K
\phi$, $B\rightarrow K^*\phi$, and $B_s\rightarrow \phi\phi$ are $(0.4\sim
2)\times 10^{-5}$, $(0.2\sim 1)\times 10^{-5}$, and $(0.15\sim 0.5)\times
10^{-5}$, respectively. The contribution from the charged Higgs boson in two
Higgs doublet models depend on $cot\beta$, and can be as large as 40\%.


title: A Note on Thermal Activation

abstract:
  Thermal activation is mediated by field configurations that correspond to
saddle points of the energy functional. The rate of probability flow along the
unstable functional directions, i.e the activation rate, is usually obtained
from the imaginary part of a suitable analytic continuation of the equilibrium
free energy. In this note we provide a real-time, non-equilibrium
interpretation of this imaginary part which is analogous to the real-time
interpretation of the imaginary part of the one-loop effective potential in
theories with symmetry breaking. We argue that in situations in which the
system is strongly out of equilibrium the rate will be time dependent and
illustrate this with an example.


title:
Construction of Fermion Mass Matrices Yielding Two Popular Neutrino
  Scenarios

abstract:
  A new procedure proposed recently enables one to start from the quark and
lepton mass and mixing data at the low scale and construct mass matrices which
exhibit simple SO(10) structure at the SUSY GUT scale. We elaborate here on the
numerical details which led us to an SO(10) model for the quark and lepton mass
matrices that explain the known quark data at the low scale along with the
observed depletions of solar- and atmospheric-neutrinos. We also apply the
procedure to a second scenario incorporating the solar-neutrino depletion and a
7 eV tau-neutrino for the cocktail model of mixed dark matter but find the
SO(10) model deduced in this case does not exhibit as simple a structure as
that observed for the first scenario.


title: Formation of Topological Defects in a Second Order Phase Transition

abstract:
  The classical evolution equations of the Abelian Higgs model are studied at
temperatures below the Ginsburg temperature of a phase transition which is
assumed to be second order. It is shown that the initial thermal fluctuations
provide a domain structure which is stable against late time fluctuations. This
result lends support to the Kibble mechanism for the formation of topological
defects.


title: On leading charmed meson production in $\pi$-nucleon interactions

abstract:
  It is shown that the D--meson, whose light quark is the initial-pion valence
quark and whose charmed quark is produced in annihilation of valence quarks and
has got a large enough momentum, is really a leading meson in reactions like
$\pi^- p -> DX$. If such annihilation of valence quarks from initial hadrons is
impossible there must be no distinct leading effect.


title:
The Fermion Determinant in External Scalar Fields: Exact Results and
  Large Mass Approximation

abstract:
  We present results for the fermion determinant in an external Yukawa-coupled
scalar field, a quantity relevant to instanton and sphaleron transition rates
as well as bubble nucleation occuring in the electroweak phase transition when
the scalar field is identified with the Higgs field. We calculate the
determinant exactly and find an approximation (essentialy of the gradient
expansion type) that reproduces the exact results very well if the fermion mass
$m_F$ becomes larger than the inverse of the size $R$ of the background field
configuration. The results are given for 2, 3 and 4 Euclidean dimensions.


title:
An Interesting Charmonium State Formation and Decay : $p \bar p \to
  ^1D_2 \to ^1P_1 \gamma$

abstract:
  Massless perturbative QCD forbids, at leading order, the exclusive
annihilation of proton-antiproton into some charmonium states, which, however,
have been observed in the $p\bar p$ channel, indicating the significance of
higher order and non perturbative effects in the few GeV energy region. The
most well known cases are those of the $^1S_0$ ($\eta_c$) and the $^1P_1$. The
case of the $^1D_2$ is considered here and a way of detecting such a state
through its typical angular distribution in the radiative decay $^1D_2 \to$
$^1P_1 \gamma$ is suggested. Estimates of the branching ratio $BR(^1D_2 \to
p\bar p)$, as given by a quark-diquark model of the nucleon, mass corrections
and an instanton induced process are presented.


title:
Disoriented Chiral Condensates and Quantum Mechanical Isospin
  Correlation

abstract:
  Classical considerations suggest that the probability distribution $P(R)$,
where $R$ is the ratio of neutral pions to total pions emitted from a
disoriented chiral condensate (which has been hypothesized to form in heavy ion
reactions) is $R^{-1/2}/2$. Quantum mechanical isospin correlations between the
condensate and the remainder of the system can alter this. Moments of the P(R)
distribution can be expressed in terms of expectation values of $(I^2/N^2)^m$
where $I$ is the isospin carried by the condensate, $N$ is the number of pions
emitted and m is an arbitrary integer. We find that the probability
distribution is very similar to the classical distribution for $0.1 < R < 0.9$
unless the isospin carried by the condensate is very large.


title:
Two-Loop Gluon-Condensate Contributions To Heavy-Quark Current
  Correlators: Exact Results And Approximations

abstract:
  The coefficient functions of the gluon condensate $<G^2>$, in the correlators
of heavy-quark vector, axial, scalar and pseudoscalar currents, are obtained
analytically, to two loops, for all values of $z=q^2/4m^2$. In the limiting
cases $z\to0$, $z\to1$, and $z\to-\infty$, comparisons are made with previous
partial results. Approximation methods, based on these limiting cases, are
critically assessed, with a view to three-loop work. High accuracy is achieved
using a few moments as input. A {\em single} moment, combined with only the
{\em leading} threshold and asymptotic behaviours, gives the two-loop
corrections to better than 1% in the next 10 moments. A two-loop fit to vector
data yields $<\frac{\alpha_{\rm s}}{\pi}G^2>\approx0.021$ GeV$^4$.


title: A Single Scale Theory for Cold and Hot Dark Matter

abstract:
  We show that a recently proposed extension of the MSSM can provide a scenario
where both the cold and hot dark matter of the universe owe their origin to a
single scale connected with the breakdown of the global B-L symmetry. The susy
partner of the majoron and the light Majorana neutrinos are the cold and hot
dark matter candidates respectively in this model and their desired relative
abundances emerge when the scale of B-L symmetry breaking is in the TeV range.


title: Diffractive jet production in a simple model with applications to HERA

abstract:
  In diffractive jet production, two high energy hadrons A and B collide and
produce high transverse momentum jets, while hadron A is diffractively
scattered. Ingelman and Schlein predicted this phenomenon. In their model, part
of the longitudinal momentum transferred from hadron A is delivered to the jet
system, part is lost. Lossless diffractive jet production, in which all of this
longitudinal momentum is delivered to the jet system, has been discussed by
Collins, Frankfurt, and Strikman. We study the structure of lossless
diffractive jet production in a simple model. The model suggests that the
phenomenon can be probed experimentally at HERA, with A being a proton and B
being a bremsstrahlung photon with virtuality $Q^2$. Lossless events should be
present for small $Q^2$, but not for $Q^2$ larger than $1/R_{\rm P}^2$, where
$R_{\rm P}$ is a characteristic size of the pomeron.


title: Topologically Stable Z - Strings in the Supersymmetric Standard Model

abstract:
  We show that the minimal supergravity extension of the standard model
automatically contains topologically stable electroweak strings if the hidden
sector is invariant under the exact R-symmetry. These defects appear in the
form of the semiglobal R-strings, which necessarily carry $Z$-flux inside their
core. This result is independent from the particular structure of the hidden
sector. Discussed strings differ fundamentally from the embedded $Z$-strings.
If R-symmetry is explicitly broken (e.g. due to an anomaly), the decay of the
semiglobal strings may have important implications for the baryogenesis.


title: Multiparticle Dynamics from 1983 to 1993

abstract:
  I compare our understanding selected topics in Multiparticle Dynamics at this
meeting to what we knew at the 1983 Multiparticle Dynamics Symposium. I also
discuss rapidity gap physics, a subject that has developed in the years since
1983


title:
The Second Moment of the Structure Function for Pseudoscalar Mesons in
  QCD Sum Rules

abstract:
  We calculate the values of the second moment $M_2^s$ of the flavor-singlet
structure function $F_2^s$ for the pion and the kaon in QCD sum rules, and
investigate how the results depend on their flavor structure (quark contents).
Our calculations give similar values of $M_2^s$ for these two mesons, because
of cancellation among several non-small factors. We emphasize that decay
constants, meson masses and quark masses play an essential role in the above
cancellation.


title: $CP$ violation in minimal supersymmetric standard model

abstract:
  $CP$ violating phenomena predicted by the minimal supersymmetric standard
model are discussed in a case where the $CP$ violating phases in SUSY sector
are not suppressed. The electric dipole moments of the neutron and the electron
are large, but can be smaller than their experimental upper bounds if the
scalar quarks and leptons are heavier than a few TeV. $T$ violating asymmetries
in the production processes of the different neutralino pair and the different
chargino pair emerge at the tree level. They could be as large as of order
$10^{-2}$ in unpolarized electron beam experiments and $10^{-1}$ in polarized
electron beam experiments. In a pair production of the charginos of the same
mass, the asymmetry emerges through the electric and the weak "electric" dipole
moments of the charginos at the loop level, but its magnitude is at most of
order $10^{-4}$.


title: Splitting the pomeron into two jets: a novel process at HERA

abstract:
  We study a novel property of large rapidity-gap events in deep inelastic
scattering at HERA: splitting the pomeron into two jets in the photon-pomeron
fusion reaction $\gamma^{*}\Pom \rightarrow q\bar{q}$. It gives rise to the
diffraction dissociation of virtual photons into the back-to-back jets. We find
that at large invariant mass $M$ of two jets, $M^{2}\gg Q^{2}$, the transverse
momentum of jets comes from the intrinsic transverse momentum of gluons in the
pomeron, and the photon-pomeron fusion direcly probes the diffrential gluon
structure function of the proton $\partial G(x,q^{2})/\partial \log q^{2}$ at
the virtuality $q^{2}\sim k^{2}$. We present estimates for the jet production
cross section, which show the process is easily measurable at HERA.


title: QCD Corrections to $\Delta\rho$

abstract:
  We discuss a simple method to evaluate the QCD corrections to $\Delta\rho$.
It assumes that the perturbative expansion in terms of $\ms$ parameters is
meaningful and, unlike other studies, exploits significant available
information concerning $\chass$ corrections. This approach leads to an
enhancement of $\sim26\%$ relative to the conventional evaluation. QCD
corrections to the $Z^0\to b\bar b$ amplitude are also considered. Implications
for electroweak physics are briefly discussed.


title: Proof of the Equivalence Theorem in the Chiral Lagrangian Formalism

abstract:
  A general proof of the equivalence theorem in electroweak theories with the
symmetry breaking sector described by the chiral Lagrangian is given in the
$R_{\xi}$ gauge by means of the Ward-Takahashi identities. The precise form of
the theorem contains a modification factor $C_{mod}$ associated with each
external Goldstone boson similar to that in the standard model. $C_{mod}$ is
exactly unity in our previously proposed renormalization scheme, {\it
Scheme-II}.


title: Hierarchical Mass Matrices in a Minimal SO(10) Grand Unification I

abstract:
  We consider a minimal SO(10) unified model with horizontal Peccei-Quinn
symmetry. The hierarchical structure of quark-lepton mass matrices is naturally
implemented by the remnants of certain irrelevant terms. Georgi-Jarlskog
relations are also realized due to the horizontal symmetry.


title:
Spherical Shells of Classical Gauge Field and their Topological Charge
  as a Perturbative Expansion

abstract:
  We consider the classical equations of motion of $SU(2)$ gauge theory,
without a Higgs field, in Minkowski space. We work in the spherical ansatz and
develop a perturbative expansion in the coupling constant $g$ for solutions
which in the far past look like freely propagating spherical shells. The
topological charge $Q$ of these solutions is typically non-integer. We then
show that $Q$ can be expressed as a power series expansion in $g$ which can be
nonzero at finite order. We give an explicit analytic calculation of the order
$g^5$ contribution to $Q$ for specific initial pulses. We discuss the relation
between our findings and anomalous fermion number violation, and speculate on
the physical implications of our results.


title: The Gerasimov-Drell-Hearn Sum Rule and Current Algebras

abstract:
  The status of the Gerasimov-Drell-Hearn sum rules for polarized inclusive
photo-production on nucleons is reviewed. It is shown that results from
currently available data compare favorably with an estimate based on an
extended current algebra. Implications for integrals of spin-dependent
structure functions are also briefly discussed.


title: Neutrino Fluxes and Resonance Physics with Neutrino Telescopes

abstract:
  Expected atmospheric ${\bar \nu_e}$ fluxes will result in a significant
number of resonantly produced low mass hadronic vector states, as the $\rho$,
in large volume neutrino telescopes. The existence of sources of higher energy
neutrinos will result in the production of higher mass states, as the $D_s^*$
and the $({\bar t}b)_{J=1}$. We calculate the rates of production of these
states and discuss their signals. Independent of theoretical flux
determinations, the detection of these states will be a tool for experimentally
determining these fluxes.


title: Signatures of Scalar Top with R-parity Breaking Coupling at HERA

abstract:
  In the framework of the minimal supersymmetric standard model with an
R-parity breaking coupling of the scalar top quark (stop) we investigate
production processes and decay properties of the stop at HERA energies. The
model is characterized by a light stop possibly lighter than the other squarks.
We show that the stop could be singly produced not only in the neutral current
processes but also in associated processes whose final states contain some
heavy flavor quarks, bottom and top quarks. These signatures would be useful to
discriminate the stop from leptoquarks.


title: Multisphalerons in the Weak Interactions

abstract:
  We construct multisphaleron solutions in the weak interactions. The
multisphaleron solutions carry Chern-Simons charge $n/2$, where $n$ is an
integer. The well-known sphaleron has $n=1$ and is spherically symmetric for
vanishing mixing angle. In contrast the multisphalerons with $n>1$ are only
axially symmetric, even for vanishing mixing angle. The greater $n$, the
stronger the energy density deforms. While for small Higgs masses the energy of
the multisphalerons is smaller than $n$ times the energy of the sphaleron, the
energy of the multisphalerons is larger than $n$ times the energy of the
sphaleron for large Higgs masses.


title: Production of Kaluza-Klein States at Future Colliders

abstract:
  Perturbative breaking of supersymmetry in four-dimensional string theories
predict in general the existence of new large dimensions at the TeV scale. Such
large dimensions lie in a domain of energies accessible to particle
accelerators. Their main signature is the production of Kaluza-Klein
excitations which can be detected at future colliders. We study this
possibility for hadron colliders (TEVATRON, LHC) and $e^+ e^-$ colliders
(LEP-200, NLC-500).


title: The Equivalence Theorem and Effective Lagrangians

abstract:
  We point out that the equivalence theorem, which relates the amplitude for a
process with external longitudinally polarized vector bosons to the amplitude
in which the longitudinal vector bosons are replaced by the corresponding
pseudo-Goldstone bosons, is not valid for effective Lagrangians. However, a
more general formulation of this theorem also holds for effective interactions.
The generalized theorem can be utilized to determine the high-energy behaviour
of scattering processes just by power counting and to simplify the calculation
of the corresponding amplitudes. We apply this method to the phenomenologically
most interesting terms describing effective interactions of the electroweak
vector and Higgs bosons in order to examine their effects on vector-boson
scattering and on vector-boson-pair production in $f\bar{f}$ annihilation. The
use of the equivalence theorem in the literature is examined.


title:
QCD Predictions for the Transverse Energy Flow in Deep-Inelastic
  Scattering in the Small x HERA Regime

abstract:
  The distribution of transverse energy, $E_T$, which accompanies
deep-inelastic electron-proton scattering at small $x$, is predicted in the
central region away from the current jet and proton remnants. We use BFKL
dynamics, which arises from the summation of multiple gluon emissions at small
$x$, to derive an analytic expression for the $E_T$ flow. One interesting
feature is an $x^{-\epsilon}$ increase of the $E_T$ distribution with
decreasing $x$, where $\epsilon = (3\alpha_s/\pi)2\log 2$. We perform a
numerical study to examine the possibility of using characteristics of the
$E_T$ distribution as a means of identifying BFKL dynamics at HERA.


title: Timelike form factors at high energy

abstract:
  The difference between the timelike and spacelike meson form factors is
analysed in the framework of perturbative QCD with Sudakov effects included. It
is found that integrable singularities appear but that the asymptotic behavior
is the same in the timelike and spacelike regions. The approach to asymptotia
is quite slow and a rather constant enhancement of the timelike value is
expected at measurable large \(Q^{2}\). This is in agreement with the trend
shown by experimental data.


title: Comment on the Dispersion Relations used to Calculate $\Delta\rho$

abstract:
  We use the operator product expansion (OPE) to show that non-perturbative QCD
corrections to $\Delta\rho$ can be calculated using unsubtracted dispersion
relations for either the transverse or the longitudinal vacuum polarization
functions. Recent calculations of the non-perturbative contribution to
$\Delta\rho$ based on a non-relativistic calculation of corrections to the
$\ttbar$ threshold are inconsistent with this result.


title: Exclusive Hadronic B Decays to Charm and Charmonium Final States

abstract:
  We have fully reconstructed decays of both B0 and B- Mesons into final states
containing either D, D*, D**, Psi, Psi', or Chi_{c1} mesons. This allows us to
obtain new results on many physics topics including branching ratios, tests of
the factorization hypothesis, color suppression, resonant substructure, and the
B- - B0 mass difference.


title: A Solution to the Polonyi Problem in the Minimum SUSY-GUT

abstract:
  We show that the Polonyi problem is solved in the minimum SUSY-GUT model in
which a self-coupling strength for a heavy Higgs $\Sigma$, $\lambda\Sigma^{3}$,
is very small $\lambda\sim 10^{-6}$. It is stressed that with this small
$\lambda$ the mass of the physical $\Sigma$ becomes $m_{\Sigma} \sim
10^{12}\GEV$ and the unification scale is raised up to the gravitational one,
$M\simeq 2\times 10^{18}\GEV$. A potential problem, however, is also pointed
out in this GUT model.


title:
QCD corrections to the t-->H+b decay within the minimal supersymmetric
  standard model

abstract:
  I present the contribution of gluinos and scalar quarks to the decay rate of
the top quark into a charged Higgs boson and a bottom quark within the minimal
supersymmetric standard model, including the mixing of the scalar partners of
the left- and right-handed top quark. I show that for certain values of the
supersymmetric parameters the standard QCD loop corrections to this decay mode
are diminished or enhanced by several 10 per cent. I show that not only a small
value of 3 GeV for the gluino mass (small mass window) but also much larger
values of several hundreds of GeV's have a non-neglible effect on this decay
rate, against general belief. Last but not least, if the ratio of the vacuum
expectation values of the Higgs bosons are taken in the limit of $v_1\ll v_2$ I
obtain a drastic enhancement due to a $\tan\beta$\ dependence in the couplings.


title: Stable, Spinning Embedded Vortices

abstract:
  The spinning vortex is a stationary generalization of the Nielsen-Olesen
vortex involving a linear time dependence of the Goldstone boson. Here we show
that this vortex can be embedded in models with $SU(2)_{global}\times
U(1)_{local}$ symmetry. We also map the stability sector in parameter space and
show that for sufficiently large spinning velocities the vortex is stable for
{\it any} value of the Higgs self coupling parameter $\beta$. This is a
significant improvement of stability compared to the semilocal vortex
introduced by Vachaspati and Achucarro which is stable only for $\beta<1$. This
result may have significant implications for electroweak vortices.


title: Triviality" and the Perturbative Expansion in $\lambda\Phi^4$ Theory

abstract:
  The "triviality" of $(\lambda\Phi^4)_4$ quantum field theory means that the
renormalized coupling $\lambda_R$ vanishes for infinite cutoff. That result
inherently conflicts with the usual perturbative approach, which begins by
postulating a non-zero, cutoff-independent $\lambda_R$. We show how a "trivial"
solution $\lambda_R=0$ can be compatible with the known structure of
perturbation theory to arbitrarily high orders, by a simple re-arrangement of
the expansion. The "trivial" solution reproduces the result obtained by
non-perturbative renormalization of the effective potential. The physical mass
is finite, while the renormalized coupling strength vanishes: the two are NOT
proportional. The classically scale-invariant $\lambda \Phi^4$ theory coupled
to the Standard Model predicts a 2.2 TeV Higgs, but does NOT imply strong
interactions in the scalar sector.


title: Signals of Disoriented Chiral Condensate

abstract:
  If a disoriented chiral condensate is created over an extended space-time
region following a rapid cooling in hadronic or nuclear collisions, the
misalignment of the condensate with the electroweak symmetry breaking can
generate observable effects in the processes which involve both strong and
electromagnetic interactions. We point out the relevance of the dilepton decay
of light vector mesons as a signal for formation of the disoriented condensate.
We predict that the decay \rho^0 to dileptons will be suppressed and/or the
\rho resonance peak widens, while the decay \omega to dileptons will not be
affected by the condensate.


title: Resummations in Hot Scalar Electrodynamics

abstract:
  The gauge-boson sector of perturbative scalar electrodynamics is investigated
in detail as a testing ground for resummation methods in hot gauge theories. It
also serves as a simple non-trivial reference system for the non-Abelian gluon
plasma. The complete next-to-leading order contributions to the polarization
tensor are obtained within the resummation scheme of Braaten and Pisarski. The
simpler scheme proposed recently by Arnold and Espinosa is shown to apply to
static quantities only, whereas Braaten-Pisarski resummation turns out to need
modification for collective phenomena close to the light-cone. Finally, a
recently proposed resummation of quasi-particle damping contributions is
assessed critically.


title: Lepton Spectra and the B Polarization at LEP

abstract:
  I review the present state of knowledge on lepton energy spectra in the
inclusive semileptonic decay of beauty hadrons, as a means to measure b
polarization effects on the Z peak. Charged-lepton as well as neutrino spectra
are considered.


title: Mass Generation in the Standard Model without Dynamical Higgs Field

abstract:
  We call attention to the fact that the gauge symmetry $SU(3)\times
SU(2)_{_L}\times U(1)$ of the Standard Model can be easily and naturally
extended by the local conformal symmetry connected with the possibility of
choosing the local length scale. Restricting the admissible interactions to the
lowest order conformal invariant interactions one gets the unique form of total
lagrangian. It contains all Standard Model fields and gravitational
interaction. Using the unitary and the conformal gauge conditions we can
eliminate all four real components of the Higgs doublet in this model. However
the masses of vector mesons, leptons and quarks are automatically generated and
are given by the same formulas as in the conventional Standard Model. In this
manner one gets the mass generation without the mechanism of spontaneous
symmetry breaking and without the remaining real dynamical Higgs field.


title: Constraints on Fermion Magnetic and Electric Moments from LEP-I

abstract:
  The effective Lagrangian approach allows us to constrain fermion magnetic and
electric moments using LEP-I data. We improve some of the previous limits on
these moments.


title: Pseudo Goldstones at Future Colliders from the Extended Bess Model

abstract:
  We consider the production of the lightest pseudo-Goldstone bosons at future
colliders through the vector resonances predicted by the extended BESS model,
which consists of an effective lagrangian parametrization with dynamical
symmetry breaking, describing scalar, vector and axial-vector bound states in a
rather general framework. We find that the detection of pseudo-Goldstone pairs
at LHC requires a careful evaluation of backgrounds. For e+e- collisions in the
TeV range the backgrounds can be easily reduced and the detection of
pseudo-Goldstone pairs is generally easier.


title:
Implications of Yukawa unification for the Higgs sector in
  supersymmetric grand-unified models

abstract:
  The SU(5) unification-scale relation h_b=h_tau between the b and tau Yukawa
couplings severely constrains tan beta and m_t (even more so if h_t=h_b= h_tau
holds) in supersymmetric models. We examine the implications of these
constraints for the Higgs sector assuming universal soft breaking terms, and
emphasize that both of these relations impose unique characteristics in terms
of symmetries and of the spectrum. We further study the tan beta near 1
scenario, which is suggested by h_b=h_tau, and, in particular, the loop-
induced mass of the light Higgs boson. We compare the effective potential and
renormalization group methods and stress the two-loop ambiguities in the
calculation of the mass. These and a large enhancement to the loop correction
due to t-scalar left-right mixing considerably weaken the upper bound.
Nevertheless, we find that for this scenario the Higgs boson is probably
lighter than 110 GeV, and typically lighter than 100 GeV. Thus, it is in the
mass range that may be relevant for LEPII. Our numerical results are presented
in a self-contained manner in section V. In separate appendices we discuss the
global symmetries of the Higgs potential, the issue of false (color-breaking)
vacua, two-loop calculations, and the effect of an additional Higgs singlet. We
show that the approximate constraints that are often used to eliminate
color-breaking vacua are not always relevant.


title: Supercollider Signatures of Supergravity Models with Yukawa Unification

abstract:
  We study the predictions of the simplest SU(5) grand unified model within the
framework of minimal supergravity, including constraints from the radiative
breaking of electroweak symmetry. As a consequence of the unification of the
$b$-quark and $\tau$-lepton Yukawa couplings, the top quark mass is predicted
to be close to its fixed point value. We delineate the regions of the
supergravity parameter space allowed by constraints from the non-observation of
proton decay and from the requirement that the LSP does not overclose the
universe. These constraints lead to a definite pattern of sparticle masses: the
feature unique to Yukawa unified models is that some of the third generation
squarks are much lighter than those of the first two generations. Despite the
fact that all sparticle masses and mixings are determined by just four SUSY
parameters at the GUT scale (in addition to $m_t$), we find that the signals
for sparticle production can vary substantially over the allowed parameter
space. We identify six representative scenarios and study the signals from
sparticle production at the LHC. We find that by studying the signal in various
channels, these scenarios may be distinguished from one another, and also from
usually studied ``minimal models'' where squarks and sleptons are taken to be
degenerate. In particular, our studies allow us to infer that some third
generation squarks are lighter than other squarks---a feature that could
provide the first direct evidence of supergravity grand unification.


title: Measuring $|V_{ub}|$ at future B-Factories

abstract:
  We calculate the so--called Fermi motion parameter $p_{_F}$ of ACCMM model
using the variational method in a potential model approach. We also propose
hadronic invariant mass distribution as an alternative experimental observable
to measure $V_{ub}$ at future asymmetric $B$ factories.


title: Chiral Morphing

abstract:
  Chiral symmetry undergoes a metamorphosis at $T_c$.
  For $T < T_c$, the usual Noether charge, $\Qa$, is dynamically broken by the
vacuum. Above $T_c$, chiral symmetry undergoes a subtle change, and the Noether
charge \underline{{\em morphs}} into $\Qbeta$, with the thermal vacuum now
becoming invariant under $\Qbeta$.
  This vacuum is however not invariant under the old $\Qa$ transformations.
  As a result, the pion remains strictly massless at high $T$.
  The pion propagates in the early universe with a halo.
  New order parameters are proposed to probe the structure of the new thermal
vacuum.


title: Dynamics of Weak First Order Phase Transitions

abstract:
  The dynamics of weak vs. strong first order phase transitions is investigated
numerically for 2+1 dimensional scalar field models. It is argued that the
change from a weak to a strong transition is itself a (second order) phase
transition, with the order parameter being the equilibrium fractional
population difference between the two phases at the critical temperature, and
the control parameter being the coefficient of the cubic coupling in the
free-energy density. The critical point is identified, and a power law
controlling the relaxation dynamics at this point is obtained. Possible
applications are briefly discussed.


title: Neutrinos with Zee-Mass Matrix in Vacuum and Matter

abstract:
  Neutrino mass matrix generated by the Zee (radiative) mechanism has zero (in
general, small) diagonal elements and a natural hierarchy of the nondiagonal
elements. It can be considered as an alternative (with strong predictive power)
to the matrices generated by the see-saw mechanism. The propagation in medium
of the neutrinos with the Zee-mass matrix is studied. The flavor neutrino
transitions are described analytically. In the physically interesting cases the
probabilities of transitions as functions of neutrino energy can be represented
as two-neutrino probabilities modulated by the effect of vacuum oscillations
related to the small mass splitting. Possible applications of the results to
the solar, supernova, atmospheric and relic neutrinos are discussed. A set of
the predictions is found which could allow to identify the Zee-mass matrix and
therefore the corresponding mechanism of mass generation.


title: Proton stability in superstring derived models

abstract:
  I discuss the problem of proton decay, from dimension four, five and six
operators, in superstring derived standard--like models. I classify the sectors
that produce color triplet superfields which may generate proton decay from
dimension five and six operators. I show that for two of these sectors there
exist a unique superstring doublet--triplet splitting mechanism that projects
out the color triplets by means of the GSO projection, while leaving the
electroweak doublets in the physical spectrum. I investigate possible proton
decay due to additional color triplets in the massless spectrum and due to
nonrenormalizable terms. I show that there exist models in which the dimension
four, five and six operators, that lead to proton decay, are forbidden by the
symmetries of the string models, to all orders of nonrenormalizable terms.


title: Hadronic Spectrum in Inclusive Semileptonic B Decays

abstract:
  We evaluate the inclusive semileptonic B decay spectrum as a function of the
final-state hadrons energy to second order in the inverse quark mass expansion
and tree level in $\alpha_{s}$. We argue that there is an energy interval below
the $c$ production threshold that could be used to determine $V_{ub}$.


title:
Axial Properties of the Nucleon with $1/N_c$-Corrections in the
  solitonic SU(3)-NJL-Model

abstract:
  Within the semibosonized SU(3)-NJL model the mass splittings of baryons and
the axial vector coupling constants of the nucleon are evaluated. The mass
splittings of the hyperons are reproduced with great accuracy if second order
corrections in $m_s$ are taken into account. New corrections to the axial
vector currents coming from the subleading terms in the $1/N_c$ expansion are
shown to be non-vanishing and substantially improving the phenomenological
predictions for axial quantities. Finally the numerical values for the $g_{\rm
A}$'s are $g_A^{(0)}=0.37$, $g_A^{(3)}=1.38$ and $g_A^{(8)}=0.31$ reproducing
reasonably well the recent data from lepton scattering.


title:
Phases in Leptonic Mass Matrices: Higher Order Invariants and
  Applications to Models

abstract:
  We discuss complex rephasing invariants of charged lepton and neutrino mass
matrices and associated theorems which determine in general (i) the number of
physically meaningful phases in these matrices and (ii) which elements of these
matrices can be rendered real by rephasings. New results are presented on
higher order complex invariants and the application of the methods to several
models.


title: Large $tan \beta$ from $SU(2)_R$ Gauge Symmetry

abstract:
  Sufficient conditions for the relation $tan \beta \simeq m_t/m_b$ to hold in
supersymmetric grand unified theories are formulated. Essential ingredients are
the $SU(2)_R$ gauge symmetry and a discrete matter parity. The applicability of
our conditions is illustrated by specific examples. Implications for neutrino
masses are discussed.


title: MSSM from SUSY Trinification

abstract:
  We construct a $SU(3)^3$ supersymmetric gauge theory with a common gauge
coupling g. Spontaneous breaking of this gauge group at a scale
$M_X=1.3\times10^{16} $GeV gives naturally rise exactly to the Minimal
Supersymmetric Standard Model $(MSSM)$ and consequently to the experimentally
favored values of $sin^2\theta_w$ and $\alpha_s$.The gauge hierarchy problem is
naturally solved by a missing-partner-type mechanism which works to all orders
in the superpotential. The baryon asymmetry can be generated in spite of the
(essential) stability of the proton. The solar neutrino puzzle is solved by the
MSW mechanism. The LSP is a natural "cold" dark matter candidate and "hot" dark
matter might consist of $\tau$-neutrinos. This model could be thought of as an
effective $4d$ theory emerging from a more fundamental theory at a scale
$M_c=M_P/\sqrt{8\pi}$ where $a_G\equiv{g^2\over{4\pi}}$ happens to be equal to
unity.


title: Strong Extended Technicolour Interactions and the $Zb\bar{b}$ Vertex

abstract:
  LEP precision measurements of the $Zb\bar{b}$ vertex coupling are
sufficiently accurate to see the non-oblique corrections from the heavy gauge
boson responsible for the large top mass in standard extended tecnicolour
models. If the ETC couplings are strong the techni-fermion condensate may be
enhanced by several orders of magnitude allowing a top mass of order 150GeV to
be obtained for large values of the ETC breaking scale sufficient to supress
the ETC contribution to the $Zb{\bar b}$ vertex. In this letter we investigate
the degree of fine tuning of the ETC coupling required in a realistic model. We
conclude that the fine tuning need only be of order $10\%$.


title: l=0 to l=1 Transition Form Factors

abstract:
  A method is proposed to extend the hard scattering picture of Brodsky and
Lepage to transitions between hadrons with orbital angular momentum l=0 and
l=1. The use of covariant spin wave functions turns out to be very helpful in
formulating that method. As a first application we construct a light-cone wave
function of the nucleon resonance $N^*(1535)$ in the quark-diquark picture.
Using this wave function and the extended hard scattering picture, the
$N$--$N^*$ transition form factors are calculated at large momentum transfer
and the results compared to experimental data. As a further application of our
method we briefly discuss the $\pi$--$a_1$ form factors in an appendix.


title:
Retarded/Advanced Correlation Functions and Soft Photon Production in
  the Hard Loop Approximation

abstract:
  We apply the retarded/advanced formalism of real time field theory to the QED
or QED like case. We obtain a general expression for the imaginary part of the
two-point correlation function in terms of discontinuities. The hard loop
expansion is derived. The formalism is used to extract the divergent part of
the soft fermion loop contribution to the real soft photon production.


title:
Measuring Hadronization Length in e^+ e^- \rightarrow K^0 {\bar{K}}^0
  \gamma

abstract:
  We propose to study the space-time picture of hadronization by looking at the
angular distribution of photons emitted in the process e^+ e^- \rightarrow K^0
{\bar{K}}^0 \gamma at DA{\Phi}NE energies. it is shown that the angular
distributions are quite sensitive to the hadronization length.


title: O(alpha_s) Longitudinal Spin Polarization in Heavy-Quark Production

abstract:
  The massive one-loop {\it QCD} corrections to the production cross sections
of We present the massive one-loop {\it QCD} corrections to the production
cross sections of polarized quarks in the annihilation process $e^+e^-\to
q\bar{q}(g)$ for bottom, top, and charm quarks. From the full analytical
expressions for the production cross sections, Schwinger-type interpolation
formulae for all parity-parity combinations $(VV, V\!A, AA)$ are derived. The
parity-odd interpolation formula contains the correct limit for vanishing quark
masses taking into account a residual coupling of left- and right-chiral states
in the massless theory. Numerical results for the total cross section and the
longitudinal spin polarization demonstrate the accuracy of the interpolation
formulae.


title: Electroweak Strings Produce Baryons

abstract:
  We propose a new mechanism to generate baryons. Electroweak strings produced
at the electroweak phase transition will introduce anomalous currents through
interactions of the strings with the background electromagnetic field and
through changes in the helicity of the string network. These anomalous currents
will produce fluctuations in the baryon and lepton number. We show that in the
two-Higgs model corrections to the action coming from the effective potential
introduce a bias in the baryon asymmetry that leads to a net baryon number
production.


title: Critical Exponents without the Epsilon Expansion

abstract:
  We argue that the sharp-cutoff Wilson renormalization group provides a
powerful tool for the analysis of second-order and weakly first-order phase
transitions. In particular, in a computation no harder than the calculation of
the 1-loop effective potential, we show that the Wilson RG yields the fixed
point couplings and critical exponents of 3-dimensional $O(N)$ scalar field
theory, with results close to those obtained in high-order $\ep$-% expansion
and large-$N$ calculations. We discuss the prospects for an even more precise
computation.


title: Observation of a New Charmed Strange Meson

abstract:
  Using the CLEO-II detector, we have obtained evidence for a new meson
decaying to $D^0 K^+$. Its mass is $2573.2^{+1.7}_{-1.6}\pm 0.8\pm 0.5$
{}~MeV/$c^2$ and its width is $16^{+5}_{-4}\pm 3$~MeV/$c^2$. Although we do not
establish its spin and parity, the new meson is consistent with predictions for
an $L=1$, $S=1$, $J_P=2^+$ charmed strange state.


title: Study of the Decay $\Lambda_c \to \Lambda l^+ \nu_{l}

abstract:
  Using the CLEO II detector at CESR, we observe 500 $\Lambda l^+$ pairs
consistent with the semileptonic decay $\Lambda_c \to \Lambda l^+ \nu_{l}$. We
measure $\sigma (e^+ e^- \to \Lambda_c X) \dot {cal B}(\Lambda_c^+ \to \Lambda
l \nu_{l}) =4.77 \pm 0.25 \pm 0.66 $pb. Combining with the charm semileptonic
width and the lifetime of the $\Lambda_c$, we also obtain ${\cal B}(\Lambda_c
\to p K^- \pi^+)$. We find no evidence for $\Lambda l^+ \nu_{l}$ final states
in which there are additional $\Lambda_c^+$ decay products. We measure the
decay asymmetry parameter of $\Lambda_c \to \Lambda l^+ \nu_{l}$ to be
$\alpha_{\Lambda_c} =-0.89\pm{^{0.17}_{0.11}}\pm{^{0.09}_{0.06}}.


title: Precision Measurement of the $D_s^{*+}- D_s^+$ Mass Difference

abstract:
  We have measured the vector-pseudoscalar mass splitting $M(D_s^{*+})-M(D_s^+)
= 144.22\pm 0.47\pm 0.37 MeV$, significantly more precise than the previous
world average. We minimize the systematic errors by also measuring the
vector-pseudoscalar mass difference $M(D^{*0})-M(D^0)$ using the radiative
decay $D^{*0}\rightarrow D^0\gamma$, obtaining
$[M(D_s^{*+})-M(D_s^+)]-[M(D^{*0})-M(D^0)] = 2.09\pm 0.47\pm 0.37 MeV$. This is
then combined with our previous high-precision measurement of
$M(D^{*0})-M(D^0)$, which used the decay $D^{*0}\rightarrow D^0\pi^0$. We also
measure the mass difference $M(D_s^+)-M(D^+)=99.5\pm 0.6\pm 0.3$ MeV, using the
$\phi\pi^+$ decay modes of the $D_s^+$ and $D^+$ mesons.


title:
A Measurement of ${\cal B}(D_s \to \phi l^+ \nu)/{cal B}(D_s\to \phi
  \pi^+)$

abstract:
  Using the CLEO~II detector at CESR, we have measured the ratio of branching
fractions ${\cal B}(D_s^+ \to \phi e^+ \nu)/{\cal B}(D_s^+ \to \phi\pi^+) =
0.54\pm 0.05\pm 0.04$. We use this measurement to obtain a model dependent
estimate of ${\cal B}(D_s^+ \to \phi \pi^+)$.


title: Measurement of Cabibbo Suppressed Decays of the $\tau$ Lepton

abstract:
  Branching ratios for the dominant Cabibbo-suppressed decays of the $\tau$
lepton have been measured by CLEO~II in $e^+ e^-$ annihilation at CESR
($\sqrt{s} \sim 10.6$~GeV) using kaons with momenta below $0.7\ \rm GeV/c$. The
inclusive branching ratio into one charged kaon is $(1.60 \pm 0.12 \pm
0.19)\%$. For the exclusive decays, $B(\tau \to K^-) = (0.66 \pm 0.07 \pm
0.09)\%$, $B(\tau \to K^- \pi^0) = (0.51 \pm 0.10 \pm 0.07)\%$, and, based on
three events, $B(\tau \to K^- \pi^0 \pi^0) < 0.3\%$ at the 90\% confidence
level. These represent significant improvements over previous results.
$B(\tau\to K^- \pi^0)$ is measured for the first time with exclusive $\pi^0$
reconstruction.


title:
Gauge Coupling Unification due to Non-universal Soft Supersymmetry
  Breaking

abstract:
  Gauge coupling unification is studied in the MSSM with non-universal soft
supersymmetry breaking terms. If gaugino masses are sufficiently smaller than
scalar soft masses and the scalar soft masses have also certain types of
non-universality, gauge coupling unification scale can be larger than $3\times
10^{16}$~GeV even within the MSSM contents. String unification may not need a
large threshold correction or a large modulus value. We also discuss the
relation to the string model building.


title:
Hadronic $ZZ$, $W^- W^+$, and $W^{\pm} Z$ Production with QCD
  Corrections and Leptonic Decays

abstract:
  The processes $p p \rightarrow V_1 V_2 + X \rightarrow \ell_1 \bar \ell_1
\ell_2 \bar \ell_2 + X$, where $V_i = W^{\pm}$ or $Z$ and $\ell_i$ denotes a
lepton, are calculated to ${\cal O}(\alpha_s)$. Total and differential cross
sections, with acceptance cuts imposed on the final state leptons, are given
for the Tevatron and LHC center of mass energies. Inclusive and exclusive
$0$-jet and $1$-jet cross sections are given. The transverse momenta spectra of
the leptons are significantly enhanced at high $p_T^{}$ by the QCD radiative
corrections, especially at the LHC energy. Invariant mass and angular
distributions are scaled up in magnitude by the QCD radiative corrections, but
are little changed in shape.


title: The Charged Neutrino: A New Approach to the Solar Neutrino Problem

abstract:
  We have considered the effect of the reduction of the solar neutrino flux on
earth due to the deflection of the charged neutrino by the magnetic field of
the solar convective zone. The antisymmetry of this magnetic field about the
plane of the solar equator induces the anisotropy of the solar neutrino flux
thus creating the deficit of the neutrino flux on the earth. The deficit has
been estimated in terms of solar and neutrino parameters and the condition of a
50 \% deficit has been obtained: $Q_{\nu} gradH \agt 10^{-18} eG/cm$ where
$Q_{\nu}$ is the neutrino electric charge, $gradH$ is the gradient of the solar
toroidal magnetic field, e is the electron charge. Some attractive experimental
consequences of this scenario are qualitatively discussed.


title: A Way to Measure Polarized Gluon Distributions

abstract:
  Effects of the spin-dependent gluon distributions on J/$\psi$ productions in
polarized ep and pp collisions are investigated. These productions serve as a
very clean probe of the spin-dependent gluon distributions in a proton.


title: How to probe the spin-dependent gluon distributions

abstract:
  Two-spin asymmetries $A_{LL}^{\pi^0}$ are calculated for various types of
spin-dependent gluon distributions. It is concluded that the E581/704 data on
$A_{LL}^{\pi^0}$ do not necessarily rule out the large gluon polarization but
restrict severely the $x$ dependence of its distribution. Moreover,
$A_{LL}^{J/\psi}$ are calculated for the forthcoming test of spin-dependent
gluon distributions.


title: On the Damping Rate of a Fast Fermion in Hot QED

abstract:
  The self-consistent determination of the damping rate of a fast moving
fermion in a hot QED plasma is reexamined. We argue how a detailed
investigation of the analytic properties of the retarded fermion Green's
function motivated by the cutting rules at finite temperature may resolve
ambiguities related to the proper definition of the mass-shell condition.


title: A Particular Class of GUTs with Vanishing One-Loop Beta Functions

abstract:
  By explicit solution of the one-loop finiteness conditions for gauge and
quartic scalar-boson self-interaction coupling constants, a particular class of
grand unified theories with vanishing Yukawa couplings as well as vanishing
one-loop renormalization-group beta functions is constructed.


title:
Phenomenology of the Two Higgs Doublet Sector of a Quark-Lepton
  Symmetric Model

abstract:
  In the simplest examples of models with a discrete quark-lepton symmetry, an
electroweak symmetry breaking sector with more than one Higgs doublet is
necessary to obtain the correct mass relations between quarks and leptons. A
two Higgs doublet model has flavour-nonconserving Yukawa couplings, which are
proportional to the masses of the quark-lepton symmetric partners of the
fermions. We describe how flavour changing leptonic decays can occur, with
branching ratios not far beyond that currently measureable, enabling
investigation of the phenomenology of such models.


title: Fermion masses and mixing angles from gauge symmetries

abstract:
  The structure of the quark and lepton masses and mixing angles provides one
of the few windows we have on the underlying physics generating the \sm. In an
attempt to identify the underlying symmetry group we look for the simplest
gauge extension of the SUSY standard model capable of generating the observed
structure. We show that the texture structure and hierarchical form found in
the (symmetric) quark and lepton mass matrices follows if one extends the gauge
group of the standard model to include an horizontal $U(1)$ gauge factor,
constrained by the need for anomaly cancellation. This $U(1)$ symmetry is
spontaneously broken slightly below the unification/string scale leaving as its
only remnant the observed structure of masses and mixings. Anomaly cancellation
is possible only in the context of superstring theories via the Green Schwarz
mechanism with $sin^2(\theta_W)=3/8$.


title: Kaon Condensation in ``Nuclear Star" Matter

abstract:
  The critical density for kaon condensation in ``nuclear star" matter is
computed up to two-loop order {\it in medium} (corresponding to
next-to-next-to-leading order in chiral perturbation theory in free space) with
a heavy-baryon effective chiral Lagrangian whose parameters are determined from
$KN$ scattering and kaonic atom data. To the order considered, the kaon
self-energy has highly non-linear density dependence in dense matter. We find
that the four-Fermi interaction terms in the chiral Lagrangian play an
important role in triggering condensation, predicting for ``natural" values of
the four-Fermi interactions a rather low critical density, $\rho_c < 4 \rho_0$.


title: Derivative Expansion of the Exact Renormalization Group

abstract:
  The functional flow equations for the Legendre effective action, with respect
to changes in a smooth cutoff, are approximated by a derivative expansion; no
other approximation is made. This results in a set of coupled non-linear
differential equations. The corresponding differential equations for a fixed
point action have at most a countable number of solutions that are well defined
for all values of the field. We apply the technique to the fixed points of
one-component real scalar field theory in three dimensions. Only two
non-singular solutions are found: the gaussian fixed point and an approximation
to the Wilson fixed point. The latter is used to compute critical exponents, by
carrying the approximation to second order. The results appear to converge
rapidly.


title: Determining the Quark Mixing Matrix From CP-Violating Asymmetries

abstract:
  If the Standard Model explanation of CP violation is correct, then
measurements of CP-violating asymmetries in $B$ meson decays can in principle
determine the entire quark mixing matrix.


title:
${\cal O}(\alpha^2 L^2)$ radiative corrections to deep inelastic $ep$
  scattering for different kinematical variables

abstract:
  The QED radiative corrections are calculated in the leading log approximation
up to ${\cal O}(\alpha^2)$ for different definitions of the kinematical
variables using jet measurement, the 'mixed' variables, the double angle
method, and a measurement based on $\theta_e$ and $y_{JB}$. Higher order
contributions due to exponentiation of soft radiation are included.


title:
Effective Lagrangian for a Technicolor Model without Exact Custodial
  Symmetry

abstract:
  Effective Lagrangian including technimesons is constructed for a realistic
one-family Technicolor model without exact custodial symmetry. Tree level
contribution to oblique correction parameters $S$ and $U$ due to spin 1
technimesons are computed with the effective Lagrangian.
  An isospin breaking term which is associated with technilepton vector mesons
gives a negative contribution to the electroweak radiative correction parameter
$S$ due to mixing between $I=0$ and $I=1$ vector mesons. $U$ receives non-zero
contribution due to exotic left-handed charged vector mesons and its sign can
be both negative and positive.


title: Chemical Equilibration in the Parton Cascade Model

abstract:
  This comment is hereby withdrawn, because the paper by D. Seibert,
KSUCNR-005-94 and nucl-th/9403005 was withdrawn and it was acknowleged that the
parton cascade model does approach chemical equilibrium correctly. Therefore
our reply to Seibert's paper is now obsolete.


title: A Model Independent Approach to Future Solar Neutrino Experiments

abstract:
  We discuss here what model independent information about properties of
neutrinos and of the sun can be obtained from future solar neutrino experiments
(SNO, Super-Kamiokande). It is shown that in the general case of transitions of
solar $\nu_e$'s into $\nu_\mu$ and/or $\nu_\tau$ the initial $^8\mathrm{B}$
neutrino flux can be measured by the observation of NC events. From the CC
measurements the $\nu_e$ survival probability can be determined as a function
of neutrino energy. The general case of transitions of solar $\nu_e$'s into
active as well as sterile neutrinos is considered. A number of relations
between measurable quantities the test of which will allow to answer the
question whether there are sterile neutrinos in the solar neutrino flux on the
earth are derived. Transitions of solar $\nu_e$'s into active and sterile
states due to neutrino mixing and Dirac magnetic moments or into active
left-handed neutrinos and active right-handed antineutrinos due to neutrino
mixing and Majorana transition magnetic moments are also considered. It is
shown that future solar neutrino experiments will allow to distinguish between
the cases of Dirac and Majorana magnetic moments.


title:
Effect of longitudinal electron polarization in the measurement of the
  $\tau$ weak dipole moment in $e^+e^-$ collisions

abstract:
  We show that certain CP-odd momentum correlations in the production and
subsequent decay of tau pairs in $e^+e^-$ collisions get enhanced when the
electron beam is longitudinally polarized. Analytic expressions for these
correlations are obtained when $\tau^+\tau^-$ have a ``weak" dipole form factor
(WDFF) coupling to $Z$ in the case of two-body decay modes of the $\tau$.
Expressions of the variance of these correlations due to the standard model
interactions are also presented. For $e^+e^-$ collisions at the $Z$ peak, a
sensitivity of about $10^{-17} e$ cm for the real part of the $\tau$ WDFF and
$3\times 10^{-17} e$ cm for the imaginary part of the $\tau$ WDFF can be
reached using $\pi$ and $\rho$ channels (which are the most sensitive channels)
in $\tau$ decay, with $10^6\, Z$'s likely to be available at the SLC at
Stanford with $e^-$ polarization of 62\%-75\%.


title:
The Two-Jet Differential Cross Section at ${\cal O}(\alpha_s^3)$ in
  Hadron Collisions

abstract:
  We study the two-jet inclusive cross section via the triply differential
distribution $d^3\sigma/dE_{T}d\eta_1 d\eta_2$ to next-to-leading order in QCD.
The predicted distributions can be compared directly with forthcoming data from
the D0 and CDF experiments at Fermilab. We discuss differences with the
leading-order predictions, and examine uncertainties due to the choice of scale
and parton density.


title: $\pi \pi$ Scattering and Pion Form Factors

abstract:
  The S and P wave $\pi \pi$ phase shifts are recalculated in terms of two
phenomenological parameters using the one loop CPTh and the elastic unitarity
condition. Using these phase shifts, the vector and scalar form factors are
calculated and shown to be in a good agreement with experimental data. It is
found that the simpler and more phenomenological approach, where the left hand
cut contributions to the partial wave amplitude are neglected, yields
approximately the same result.


title: Leptonic CP Violation in Supersymmetric Standard Model

abstract:
  We point out the possibility of spontaneous and hard CP-violation in the
scalar potential of R-parity broken supersymmetric Standard Model. The
existence of spontaneous CP-violation depends crucially on the R-parity
breaking terms in the superpotential and, in addition, on the choice of the
soft supersymmetry breaking terms. Unlike in theories with R-parity
conservation, it is natural, in the context of the present model, for the
sneutrinos to acquire (complex) vacuum expectation values. In the context of
this model we examine here the global implications, like the strength of the
CP-violating interactions and the neutrino masses.


title:
Constraints on Baryon-Nonconserving Yukawa Couplings in a Supersymmetric
  Theory

abstract:
  The 1-loop evolution of couplings in the minimal supersymmetric standard
model, extended to include baryon nonconserving $(B\!\!\!/)$ operators through
explicit $R$-parity violation, is considered keeping only $B\!\!\!/$
superpotential terms involving the maximum possible number of third generation
superfields. If all retained Yukawa couplings $Y_i$ are required to remain in
the perturbative domain $(Y_i < 1)$ upto the scale of gauge group unification,
upper bounds ensue on the magnitudes of the $B\!\!\!/$ coupling strengths at
the supersymmetry breaking scale, independent of the model of unification. They
turn out to be similar to the corresponding fixed point values reached from a
wide range of $Y_i$ (including all $Y_i$ greater than unity) at the unification
scale. The coupled evolution of the top and $B\!\!\!/$ Yukawa couplings results
in a reduction of the fixed point value of the former.


title: QCD Accurately Predicts the Induced Pseudoscalar Coupling Constant

abstract:
  Using chiral Ward identities of QCD, we derive a relation for the induced
pseudoscalar coupling constant which is accurate within a few percent, $g_P =
8.44 \pm 0.16$.


title: Possible reason why leptons are lighter than quarks

abstract:
  The minimal model of spontaneously broken leptonic colour and discrete
quark-lepton symmetry predicts that charged leptons have the same masses as
their partner charge $+2/3$ quarks up to small radiative corrections. By
invoking a different pattern of symmetry breaking, a similar model can be
constructed with the structural feature that charged leptons have to be lighter
than their partner quarks because of mixing between leptonic colours, provided
mixing between generations is not too strong. As well as furnishing a new
model-building tool, this is phenomenologically interesting because some of the
new physics responsible for the quark-lepton mass hierarchy could exist on
scales as low as several hundred GeV.


title: Quantum Scattering from Classical Field Theory

abstract:
  We show that scattering amplitudes between initial wave packet states and
certain coherent final states can be computed in a systematic weak coupling
expansion about classical solutions satisfying initial value conditions. The
initial value conditions are such as to make the solution of the classical
field equations amenable to numerical methods. We propose a practical procedure
for computing classical solutions which contribute to high energy two particle
scattering amplitudes. We consider in this regard the implications of a recent
numerical simulation in classical SU(2) Yang-Mills theory for multiparticle
scattering in quantum gauge theories and speculate on its generalization to
electroweak theory. The generalization of our results to complex trajectories
allows its application to it any wave packet to coherent state transition.
Finally, we discuss the relevance of these results to the issues of baryon
number violation and multiparticle scattering at high energies.


title:
Seesaw-Type Quark and Lepton Mass Matrices and U(3)-Family Nonet Higgs
  Bosons

abstract:
  A unified mass matrix model of quarks and leptons with a seesaw-type form
$M_f=m M_F^{-1} m$ is proposed on the basis of a non-standard Higgs scenario.
The matrix $m$ is provided by U(3)-family nonet bosons $\phi$, and the matrix
$M_F$ is a mass matrix of heavy fermions $F_i$ corresponding to the ordinary
fermions $f_i=\nu_i,e_i,u_i,d_i$ ($i=1,2,3$). It is shown that a Higgs
potential of $\phi$ with a broken U(3)-family symmetry leads to a desirable
charged lepton mass formula when $M_E\propto {\bf 1}$. Then, phenomenologically
desirable forms of heavy quark mass matrices $M_Q$ ($Q=U,D$) are investigated.


title: Covariant model of a quarkonium with the funnel potential

abstract:
  The bound--state problem for the pion as a quarkonium with the funnel
(Coulomb--plus--linear) interaction is solved in a framework that combines the
bilocal approach to mesons with the covariant generalization of the
instantaneous--potential model. The potential interaction leads to dynamical
breaking of chiral symmetry. However, the Coulomb potential leads to
ultraviolet divergences that must be subtracted. A careful choice of the
renormalization prescription is needed in order to get the correct chiral
limit. The mass, the lepton decay constant of the pion, as well as the pion
decay width in two photons are calculated.


title:
An alternative model for the electroweak symmetry breaking sector and
  its signature in future e-gamma colliders

abstract:
  We perform a preliminary study of the deviations from the Standard Model
prediction for the cross section for the process $e \gamma \rightarrow \nu_e W
\gamma$. We work in the context of a higgsless chiral lagrangian model that
includes an extra vector resonance $V$ and an anomalous $\gamma W V$ coupling.
We find that this cross section can provide interesting constraints on the free
parameters of the model once it is measured in future $e \gamma$ colliders.


title: Indirect Detection of WIMPs

abstract:
  I review several proposed techniques for indirect detection of weakly
interacting massive particles (WIMPs) in the halo. I focus on distinctive
signatures from cosmic-ray positrons, antiprotons, and gamma rays produced by
annihilation of WIMPs in the galactic halo. (To appear in Particle
Astrophysics, Atomic Physics, and Gravitation}, proceedings of the the XIVth
Moriond Workshop, Villars sur Ollon, Switzerland, Jan. 22-29, 1994.)


title: Search for Anomalous Couplings at $e\gamma$ Colliders

abstract:
  We consider the possibility of observing deviations from the Standard Model
gauge-boson self-couplings at future $e\gamma$ colliders. We concentrate on the
process $e^-\gamma \rightarrow \nu W^- Z$, which is particularly sensitive to
the parity violating coupling $g_5^Z$ at high energies. We find that a 2~TeV
$e^+ e^-$ collider operating in the $e^- \gamma$ mode could reach a sensitivity
of order $5\times 10^{-3}$ to $g_5^Z$.


title: Production and Decay of D_1(2420)^0 and D_2^*(2460)^0

abstract:
  We have investigated $D^{+}\pi^{-}$ and $D^{*+}\pi^{-}$ final states and
observed the two established $L=1$ charmed mesons, the $D_1(2420)^0$ with mass
$2421^{+1+2}_{-2-2}$ MeV/c$^{2}$ and width $20^{+6+3}_{-5-3}$ MeV/c$^{2}$ and
the $D_2^*(2460)^0$ with mass $2465 \pm 3 \pm 3$ MeV/c$^{2}$ and width
$28^{+8+6}_{-7-6}$ MeV/c$^{2}$. Properties of these final states, including
their decay angular distributions and spin-parity assignments, have been
studied. We identify these two mesons as the $j_{light}=3/2$ doublet predicted
by HQET. We also obtain constraints on {\footnotesize $\Gamma_S/(\Gamma_S +
\Gamma_D)$} as a function of the cosine of the relative phase of the two
amplitudes in the $D_1(2420)^0$ decay.


title:
Gravitational uncertainties from dimension-six operators on
  supersymmetric GUT predictions

abstract:
  We consider the gravity induced dimension six terms in addition to the
dimension five terms in the SUSY GUT Lagrangian and find that the prediction
for $\alpha_s$ may be washed out completely in supersymmetric grand unified
theories unless the triplet higgs mass is smaller than $ 7\times 10^{16} $ GeV.


title:
Angular Distributions in the Drell-Yan Process: A Closer Look at Higher
  Twist Effects

abstract:
  We calculate the angular distribution of the lepton produced in the Drell-Yan
reaction taking into account pion bound state effects. We work in the kinematic
region where one of the pion constituents goes far off-shell, which allows us
to treat the bound state problem perturbatively. We show that the angular
distribution is very sensitive to the shape of the pion distribution amplitude.
The model we discuss fits the data if we choose a two-humped pion distribution
amplitude suggested by QCD sum rules.


title:
LHC Detection of Neutral MSSM Higgs Bosons via $gg\rta b\anti b \h\rta
  b\anti b b\anti b$

abstract:
  We demonstrate that simultaneous detection of two of the neutral Higgs bosons
of the Minimal Supersymmetric Model will be possible at the LHC in the $b\anti
b b\anti b$ final state, provided $\tanb$ is large and $b$-tagging can be
performed with good efficiency and purity. This mode enhances the already
established guarantee that there is no region of supersymmetric parameter space
for which {\it none} of the Higgs bosons of the model can be seen at the LHC.