title: Semianalytic Cascade Theory

abstract:
  We give a simple, semianalytic theory of the development of the hadronic and
neutrino/muon components of a cascade induced by a primary which produces
hadrons at the initial interaction. The main purpose of the theory is to allow
the user to obtain quick, but reasonably reliable estimates of the longitudinal
properties of such cascades developing in a medium, such as a stellar interior,
the atmosphere and/or water. As an application, we discuss the possibility of
discovering physics beyond the Standard Model by means of neutrino telescopes.
Some of those events may have spectacular signatures in neutrino telescopes.
[LaTeX, no outside macros needed. 3 figures, available in hard copy or by
E-mail as Encapsulated PostScript (EPS) files.]


title:
The Quark Propagator from the Dyson-Schwinger Equations: I. the Chiral
  Solution

abstract:
  Within the framework of the Dyson-Schwinger equations in the axial gauge, we
study the effect that non-perturbative glue has on the quark propagator. We
show that Ward-Takahashi identities, combined with the requirement of matching
perturbative QCD at high momentum transfer, guarantee the multiplicative
renormalisability of the answer. Technically, the matching with perturbation
theory is accomplished by the introduction of a transverse part to the
quark-gluon vertex. We show that this transverse vertex is crucial for chiral
symmetry breaking, and that massless solutions exist below a critical value of
the strong coupling constant. Using the gluon propagator that we previously
calculated, we obtain small corrections to the quark propagator, which keeps a
pole at the origin in the chiral phase.


title: Analysis of one particle excitations in phenomenological models of QCD

abstract:
  In these notes for the quark Nambu-Jona-Lasinio model and for the
phenomenological four fermionic model of QCD we analyze vacuum energy structure
and calculate dependence of energy of one-particle excitations on momentum. We
reveal existence of two different types of excitations above the vacuum with
the respective minimization of the vacuum energy density. First type of
excitation energy spectrum is the usual spectrum of relativistic massive
particle, but the second one has a linear dependence on momentum.


title:
Solution of The Heisenberg Equation For The Four-fermion Contact
  Interaction by The Method of Dynamical Mappings

abstract:
  In the paper we consider non-relativistic analog of the Nambu-Jona-Lasinio
model and demonstrate, by this most simplified example, the method of dynamical
mappings of Heisenberg fields on "physical" fields. We obtain the expressions
for one particle eigen-excitation spectrum of full Hamiltonian (spectrum of
"clad" fermions), wave function of two excitations' bound state and its mass,
and compute the Bethe-Solpither amplitude. We derive as well the relation for
the density of vacuum energy as a function of mapping parameters. The
minimization of energy leads us to the fixation of these parameters. The method
admits the generalization on the relativistic case.


title: New probes of anomalous $WW\gamma$ couplings at future $e^+e^-$ linacs

abstract:
  We investigate the sensitivity of single photon plus missing energy
cross-sections at future $e^{+}e^{-}$ linacs to non-standard $WW\gamma$
couplings. We show that even with conservative estimates of systematic errors
there is still considerable sensitivity to anomalous couplings. Analytic
expressions for helicity amplitudes are presented.


title: Hadrons with Two Heavy Quarks

abstract:
  We review the spectroscopy and some properties of hadrons containing two
charmed quarks, or more generally, two heavy quarks. This includes heavy
baryons such as $(bcu)$, and possible exotic multiquark states.


title:
Angular Correlations and Light Gluinos in Multi-jet Photoproduction at
  HERA

abstract:
  A study of $3+1$ jet event photoproduction at HERA is presented. We define an
angular variable which is sensitive to the topology of the final state jets and
is therefore able to discriminate between the different contributing
subprocesses, and between QCD and an abelian gluon model. We also investigate
the contribution from the direct production of light gluinos to the $3+1$ cross
section.


title:
Updating the Unitarity Triangle: Top Quark Mass Versus Nonperturbative
  Uncertainties

abstract:
  We summarize the present knowledge on the non-perturbative hadronic inputs
needed in the analysis of $B^0$-$\bar B^0$ mixing and the CP-violating
parameter $\varepsilon$ of the $K^0$-$\bar K^0$ system. Using this information,
together with the recently determined value of the top-quark mass, we update
the phenomenological constraints on the unitarity triangle.


title: The Role of Screening Corrections in High Energy Photoproduction

abstract:
  The role of screening corrections, calculated using the eikonal model, is
discussed in the context of soft photoproduction. We present a comprehensive
calculation considering the total,elastic and diffractive cross sections
jointly. We examine the differences between our results and those obtained from
the supercritical Pomeron-Reggeon model with no unitarity corrections.


title:
A model calculation of the value of the electromagnetic coupling
  constant at $q^2 = m_{Z}^{2}$

abstract:
  A QCD model with an infinite number of vector mesons suggested by one of the
authors is used to derive the value of the correction $\delta\alpha_{hadr}$ for
$\alpha(m_{Z}^{2})$ due to the strong interactions. The result is
$\delta\alpha_{hadr} = 0.0275(2)$ ; thus $\alpha(m^{2}_{Z}) =
(128.96(3))^{-1}$.


title: Large Top and Bottom Yukawa Couplings in Minimal Supersymmetry

abstract:
  We present analytic expressions for the top and bottom Yukawa couplings in
the context of the minimal supersymmetric standard model when both couplings
$h_{t,0},h_{b,0}$ are large at the unification scale. For sufficiently large
$h_{t,0},h_{b,0}$, i.e. within $\sim (20-25)\% $ close to their fixed point
values, using as input the central value of the bottom mass $m_b(m_b)=4.25GeV$,
we find that the top mass lies in the range $m_t \approx (174-178)GeV$, while
$tan\beta \approx (55-58)$. Implications on the evolution of the scalar masses
and the radiative symmetry breaking scenario are discussed.
  %


title:
The magnitude of the gluon condensate and the masses of $c$ and $b$
  quarks from the families of ${\cal J}$/$\Psi$ and $\Upsilon$ mesons

abstract:
  It is shown that the model used in [1] for the description of the
experimental function $R_c (s)$ in the form of a sum of $\delta$-functions and
the plateau contradicts the Wilson operator expansion (O.E.) in the terms due
to the gluon condensate. A QCD model with an infinite number of vector mesons
[12,13] does satisfy the requirements of the O.E. for masses and electronic
widths resonances close to the experimental values. The region of allowable
values of the masses of $c$ and $b$-quarks and the gluon condensate compatible
with the O.E. is obtained (Figs. 2,3).


title: Physics at High Energy Photon Photon Colliders

abstract:
  I review the physics prospects for high energy photon photon colliders,
emphasizing results presented at the LBL Gamma Gamma Collider Workshop.
Advantages and difficulties are reported for studies of QCD, the electroweak
gauge sector, supersymmetry, and electroweak symmetry breaking.


title:
Initial State Radiation to Off-shell $\Z^0$ Pair Production in $e^+e^-$
  Annihilation

abstract:
  A study of the Standard Model reaction $\e^+e^- \rightarrow (\Z^0\Z^0)
\rightarrow f_1\bar{f_1}f_2\bar{f_2}$ including the effects of the finite
$\Z^0$~width and initial state radiative corrections is presented. All angular
phase space integrations are performed analytically. The remaining invariant
masses are integrated numerically. Semi-analytical and numerical results in the
energy range $\RS=200\;GeV$ to $1\;TeV$ are reported.


title:
Higher order corrections to bound state energy levels in QED: an
  effective field theory approach

abstract:
  In T.Zhang, L.Xiao and R.Koniuk, Can. J. Phys. {\bf 70}, 670 (1992), a new
method was developed to calculate energy levels in QED nonrelativistic bound
states, up to order m \alpha^5. Whether or not this method could be used beyond
this order was left as an open question. In this paper, we answer this question
with the help of a nonrelativistic effective field theory, NRQED. We find that,
aside from infrared terms which had to be discarded without justification in
Zhang et al, the order m \alpha^4 and m \alpha^5 calculations give the same
results in both methods. It is shown, however, that this is due to the special
physical origin of these contributions and that the method of Zhang et al would
not give the right answer at order m \alpha^6 or higher. The separation of
scale provided by NRQED is essential to the derivation of this result.


title: A Short Note on Two-Loop Box Functions

abstract:
  It is shown that the two-loop four-point functions are similar in structure
to the three-point two-loop functions for all mass cases and topologies. The
result is derived by using a rotation to a (+,-,-,+) signature without spoiling
analyticity properties.


title:
Application of conformal mapping and Pad\'{e} approximants $(\omega
  P's)$ to the calculation of various two-loop Feynman diagrams

abstract:
  Feynman diagrams are calculated by means of their Taylor series expansion in
terms of external momenta squared. It is demonstrated in various examples that
by the application of conformal mapping and Pad\'{e} approximants, it is
possible to obtain high precision results in the spacelike as well as in the
timelike region on the cut. Examples are given for two- and three-point
functions, but in principle the method is applicable also to four-point
functions.


title: New Tensor Interactions in $\mu$ Decay

abstract:
  The most general form of the hamiltonian for the muon decay is presented. We
assume that it arises as a result of the exchange of intermediate bosons with a
momentum $q$ and naturally should depend on this momentum. That allows us to
introduce two additional coupling constants for the tensor interactions which
give rise to new parameters in the energy spectrum of positrons. The
experimental consequences of such a generalization are discussed.


title: New Tensor Interactions and the $K_L$-$K_S$ Mass Difference

abstract:
  The minimal standard electroweak model yields approximately half the observed
value of the $K_L$-$K_S$ mass difference. Antisymmetric tensor fields
incorporated into the standard model can provide the rest $0.5\times(\Delta
m_{LS})_{\exp}$. The effective lepton--lepton, quark--lepton and quark--quark
tensor interactions induced by the charged tensor particles are presented.


title:
Loop corrections to the sphaleron transition rate in the minimal
  standard model

abstract:
  The baryon number dissipation rate due to sphaleron transitions at high
temperatures in the minimal standard model is evaluated. We find that this rate
can be considerably suppressed by one loop contributions of bosonic and
fermionic fluctuations which are particularly important for a small mass of the
Higgs boson and a large top quark mass. Fixing the latter to its recently
stated value of 174 GeV the complete erasure of the baryon asymmetry is
prevented within the framework of the minimal standard model if the Higgs mass
is less than about 66 GeV.


title: Fermion masses and mixings in a flavour symmetric GUT

abstract:
  We describe a supersymmetric Grand Unified Theory based on the gauge group
$\SU(5)^3$, or $\SO(10)^3$, invariant under the interchange of any~SU(5),
or~SO(10), with each family multiplet transforming non trivially under one
different individual group factor. A realistic pattern of fermion masses and
mixings is obtained as a result of an appropriate choice out of the many
possible discretely degenerate vacua of the theory. In the~SO(10) case, we
predict the three neutrino masses in terms of an overall scale and, within
factors of order unity, their mixing angles. A $\nu_e$-$\nu_\mu$ oscillation is
suggested as a solution of the solar neutrino problem, implying a visible
$\nu_\mu$-$\nu_\tau$ oscillation in the forthcoming experiments. Grand unified
theories of this type could be obtainable in a string theory framework.


title: The pion-nucleon interaction as an effective field theory

abstract:
  After a brief survey of effective field theories, the linear sigma model is
discussed as a prototype of an effective field theory of the standard model
below the chiral-symmetry-breaking scale. Although it can serve as a toy model
for the pion-nucleon interaction, the linear sigma model is not a realistic
alternative to chiral perturbation theory. The heavy-baryon approach to chiral
perturbation theory allows for a systematic low-energy expansion of Green
functions and amplitudes with baryons. The chiral-invariant renormalization of
the effective field theory for the pion-nucleon system to O(p^3) in the chiral
expansion is reviewed.


title: Chern-Simons number diffusion in (1+1)-dimensional Higgs theory

abstract:
  We study the Chern-Simons number diffusion rate in the (1+1)-dimensional
latticeAbelian Higgs model at temperatures much higher than, as well as
comparable to, the sphaleron energy. It is found that in the high-temperature
limit the rate is likely to grow as power 2/3 of the temperature. In the
intermediate-temperature regime, our numerical simulations show that very weak
temperature dependence of the rate, found in previous work, persists at smaller
lattice spacings. We discuss possibilities of relating the observed behavior of
the rate to static finite-temperature properties of the model.


title:
Beauty Physics in the Next 15 Years -- an Itinerary for a Long Journey
  towards an Essential Goal

abstract:
  After re-stating why beauty physics is so special and sketching its present
status I attempt to map out an itinerary for the next fifteen years. The basic
elements are listed for a research program that allows to define and probe the
KM unitarity triangle in a manner where the numerical uncertainties are reduced
to the few percent level. Dedicated experiments at the LHC will be essential in
exploiting the discovery guarantee in beauty physics to the fullest. This paper
is dedicated to Prof. H. Kastrup on the occasion of his 60th birthday. I have
spent five years at his institute at the RWTH Aachen and I truly enjoyed the
stimulating atmosphere he created by encouraging intellectual exchange
unimpeded by hierarchical privileges.


title:
CP Violation in Beauty Decays -- the Standard Model Paradigm of Large
  Effects

abstract:
  The Standard Model contains a natural source for CP asymmetries in weak
decays, which is described by the KM mechanism. Beyond $\epsilon _K$ it
generates only elusive manifestations of CP violation in {\em light-}quark
systems. On the other hand it naturally leads to large asymmetries in certain
non-leptonic beauty decays. In particular when $B^0-\bar B^0$ oscillations are
involved, theoretical uncertainties in the hadronic matrix elements either drop
out or can be controlled, and one predicts asymmetries well in excess of 10\%
with high parametric reliability. It is briefly described how the KM triangle
can be determined experimentally and then subjected to sensitive consistency
tests. Any failure would constitute indirect, but unequivocal evidence for the
intervention of New Physics; some examples are sketched. Any outcome of a
comprehensive program of CP studies in $B$ decays -- short of technical failure
-- will provide us with fundamental and unique insights into nature's design.


title: A Dynamical Origin for the Top Mass

abstract:
  We describe a dynamical scheme by which isospin breaking feeds strongly into
the $t$ and $b$ masses and not into the $W$ and $Z$ masses. The third family
feels a new gauge interaction broken close to a TeV.


title: Relativistic Oscillator Model and Delbr\"uck scattering

abstract:
  Elastic scattering of photons in a Lorentz-scalar potential via virtual
spin-zero particle-antiparticle pairs (`` Delbr\"uck scattering") is
considered. An analytic expression for the Delbr\"uck amplitude is found
exactly in case of an oscillator potential. General properties of the amplitude
and its asymptotics are discussed.


title: The Top Quark and the Higgs Boson Mass from LEP SLC and CDF Data

abstract:
  The impact of the new experimental data from LEP, SLC and CDF on the top
quark mass and the Higgs boson mass is investigated. The determinations of
m_{top} and of an upper bound on m_{Higgs} are given, taking into account the
experimental error on the QED coupling constant \alpha_{em} and on the b-quark
mass m_b. The relevance of higher order theoretical uncertainties is pointed
out. briefly reviewed.


title: Universe Reheating after Inflation

abstract:
  We study the problem of scalar particle production after inflation by a
rapidly oscillating inflaton field. We use the framework of the chaotic
inflation scenario with quartic and quadratic inflaton potentials. Particular
attention is paid to parametric resonance phenomena which take place in the
presence of the quickly oscillating inflaton field. We have found that in the
region of applicability of perturbation theory the effects of parametric
resonance are crucial, and estimates based on first order Born approximation
often underestimate the particle production. In the case of the quartic
inflaton potential $V(\varphi) = \lambda \varphi^4$, the particle production
process is very efficient even for small values of coupling constants. The
reheating temperature of the universe in this case is $\left[\lambda\, \log\,
(1/\lambda) \right]^{- 1}$ times larger than the corresponding estimates based
on first order Born approximation. In the case of the quadratic inflaton
potential the reheating process depends crucially on the type of coupling
between the inflaton and the other scalar field and on the magnitudes of the
coupling constants. If the inflaton coupling to fermions and its linear (in
inflaton field) coupling to scalar fields are suppressed, then, as previously
discussed by Kofman, Linde and Starobinsky (see e.g. Ref. 13), the inflaton
field will eventually decouple from the rest of the matter, and the residual
inflaton oscillations may provide the (cold) dark matter of the universe. In
the case of the quadratic inflaton potential we obtain the lowest and the
highest possible bounds on the effective energy density of the inflaton field
when it freezes out.


title: Solving the Cosmological Moduli Problem with Weak Scale Inflation

abstract:
  Many models of supersymmetry breaking involve particles with weak scale mass
and Planck mass suppressed couplings. Coherent production of such particles in
the early universe destroys the successful predictions of nucleosynthesis. We
show that this problem may be solved by a brief period of weak scale inflation.
Furthermore the inflaton potential for such an inflation naturally arises from
the same assumptions which lead to the cosmological problem. Successful
baryogenesis and preservation of density fluctuations for large scale structure
formation are also possible in this scenario.


title:
Resummation of Perturbation Series in Non-Equilibrium Scalar Field
  Theory

abstract:
  The general behaviour of perturbation series in non-equilibrium scalar field
theory is analysed in some detail, with a particular emphasis on the
``pathological terms'', generated by multiple products of $\delta$-functions.
Using an intuitive regularization method, it is shown that these terms give
large contributions at all orders, even when considering small deviations from
equilibrium. Fortunately, these terms can also be resummed and I give the
general expressions for the resummed propagators in non-equilibrium scalar
field theory, regardless of the size of deviations from equilibrium.


title: Intrinsic Transverse Size Effect

abstract:
  Two recently proposed concepts to improve the perturbative calculation of
exclusive amplitudes, gluonic radiative corrections (Sudakov factor) and
confinement size effects (intrinsic transverse momentum) are combined to study
the neutron magnetic form factor in the space-like region. We find that nucleon
distribution amplitudes modelled on the basis of current QCD sum rules indicate
overlap with the existing data at the highest measured values of momentum
transfer. However, sizeable higher-order perturbative corrections (K-factor)
and/or higher-twist contributions cannot be excluded, although they may be
weaker than in the proton case.


title:
Implications of non-universality of soft terms in supersymmetric grand
  unified theories

abstract:
  Most discussions of supersymmetric grand unified theories assume universality
of the soft supersymmetry breaking terms at the grand scale. We point out that
the behaviour of these theories might change significantly in the presence of
non--universal soft terms. Particularly in SO(10)--like models with a large
value of tan$\beta$ we observe a decisive change of predictions, allowing the
presence of relatively light gauginos as well as small supersymmetric
corrections to the b--quark mass. Some results remain rather stable, including
the $\mu$--$M_{1/2}$ correlation. Models with small tan$\beta$ seem to be less
affected by non--universality which mainly leads to the new possibility of
small $m_{0}$ (i.e. the squark and slepton soft mass parameter), excluded in
the universal case.


title: Quantum Phenomenology for the Disoriented Chiral Condensate

abstract:
  We consider the quantum state describing theDisoriented Chiral Condensate
(DCC), which may be produced in high energy collisions. We show how a mean
field treatment of the quantum equations corresponding to the classical linear
sigma model leads to a squeezed state description of the pions emerging from
the DCC. We examine various squeezed and coherent state descriptions of those
pions with particular attention to charge and number fluctuations. We also
study the phenomenology of multiple DCC domains.


title: Phenomenology of the Minimal Supergravity SU(5) Model

abstract:
  The minimal grand unified supergravity model is discussed. Requiring
radiative breaking of the electroweak gauge symmetry, the unification of b and
tau Yukawa couplings, a sufficiently stable nucleon, and not too large a relic
density of neutralinos produced in the Big Bang constrains the parameter space
significantly. In particular, the soft breaking parameter m_1/2 has to be less
than about 130 GeV, and the top quark Yukawa coupling has to be near its
(quasi) fixed point. The former condition implies m_gluino < 400 GeV and hence
very large production rates for gluino pairs at the LHC, while the latter
constraint implies that the lighter stop and sbottom eigenstates are
significantly lighter than the other squarks, leading to characteristic
signatures for gluino pair events.


title:
Maximal $CP$ violation in the Higgs Sector and its Effect on the $\rho$
  Parameter

abstract:
  We study the conditions of maximal $CP$ violation in the neutral Higgs mass
matrix of the two Higgs doublet model. We get fixed values of $\tan\b$ and
constraints on the Higgs potential parameters. Two neutral Higgs scalars are
constrained to be lighter than the charged Higgs scalar and these two Higgs
scalars are expected to be almost degenerate due to the smallness of the $h$
parameter, where $h$ is the CP violating coupling constant of the Higgs
interaction. The radiative correction of the $\rho$ parameter from the Higgs
scalar exchange is rather small and its sign negative for a wide range of Higgs
masses. It follows that maximum $CP$ violation in the two Higgs doublet model
is safely allowed for the $\rho$ parameter without the custodial symmetry.


title: What Charm Can Tell Us About Beauty

abstract:
  A number of ways are reviewed in which the study of charmed particles can
answer corresponding questions about particles containing $b$ quarks. Topics
include the properties of resonances, the magnitude of decay constants, the
size of spin-dependent effects, and the hierarchy of lifetime differences.


title: Our Present Understanding of CP Violation

abstract:
  If CP violation in the decays of neutral kaons is due to phases in the weak
couplings of quarks, as encoded in the Cabibbo-Kobayashi-Maskawa (CKM) matrix,
there are many other experimental consequences. Notable among these are
CP-violating rate asymmetries and triangle relations among decay rates in $B$
meson decays, while charmed particle decays should not be a good place to see
CP-violating effects. In the context of the CKM and other models of CP
violation, we discuss phenomena such as electric dipole moments, the baryon
asymmetry of the Universe, and the strong CP problem, and speculate on a common
origin for CP-violating phenomena.


title: The Spin Structure of the Proton in a Non-relativistic Quark Model

abstract:
  The spin structure of the proton is investigated in the framework of an
extended quark potential model which in addition to the conventional
$3q$--structure also takes into account $(3q)(q\bar q)$--admixtures in the
proton wave function. For reasons of parity such admixtures contain an odd
orbital angular momentum thus allowing the proton spin to be shared among quark
spins and orbital angular momenta. We show that only certain admixtures are
suited for a significant reduction of the quark spin content of the proton as
suggested by the EMC--result. Within a Hamiltonian model quark spin
contributions to the proton spin down to $0.5$ can be reproduced easily.


title: Phenomenology of a non-standard top quark Yukawa coupling

abstract:
  There are theoretical speculations that the top quark may have different
properties from that predicted by the standard model. We use an effective
Lagrangian technique to model such a non-standard top quark scenario and study
its effects on the electroweak baryogenesis, low and high energy physics.


title:
Strong $\Lambda \pi$ Phase Shifts for CP Violation in Weak $\Xi
  \rightarrow \Lambda \pi$ Decay

abstract:
  Strong interaction $\Lambda\pi$ phase shifts relevant for the weak
nonleptonic decay $\Xi \rightarrow \Lambda \pi$ are calculated using baryon
chiral perturbation theory. We find in leading order that the S-wave phase
shift vanishes and the $J={1 \over 2}$ P-wave phase shift is $-1.7 ^{\rm o} $.
The small phase shifts imply that CP violation in this decay will be difficult
to observe. Our results follow from chiral $SU(2)_L\times SU(2)_R$ symmetry.


title: On the scheme dependence of the Electroweak radiative corrections

abstract:
  We study the scheme dependence of the two-loop expression for the
$\rho$-parameter of the Standard Model in the heavy $t$-quark mass limit $m_{t}
\gg m_{w}$. In the $\ms$-scheme the two-loop electroweak correction to the
${\cal O}(m_{t}^{2})$ term in $\dr$ is found greater than the QCD
$\as$-correction.


title:
Strangeness Production in pp,pA,AA Interactions at SPS Energies.HIJING
  Approach

abstract:
  In this report we have made a systematic study of strangeness production in
proton-proton(pp),proton-nucleus(pA) and nucleus- nucleus(AA) collisions at
CERN Super Proton Synchroton energies, using$\,\,\, HIJING\,\,\, MONTE
\,\,\,CARLO \,\,\,MODEL $ \\ (version $HIJ.01$). Numerical results for mean
multiplicities of neutral strange particles ,as well as their ratios to
negatives hadrons($<h^{-}>$) for
p-p,nucleon-nucleon(N-N),\,\,p-S,\,\,p-Ag,\,\,p-Au('min. bias')collisions and
p-Au,\,\,S-S,\,\,S-Ag,\,\,S-Au ('central')collisions are compared to
experimental data available from CERN experiments and also with recent
theoretical estimations given by others models. Neutral strange particle
abundances are quite well described for p-p,N-N and p-A interactions ,but are
underpredicted by a factor of two in A-A interactions for
$\Lambda,\bar{\Lambda},
  K^{0}_{S}$ in symmetric collisions(S-S,\,\,Pb-Pb)and for
$\Lambda,\bar{\Lambda}\,\,$in asymmetric ones(S-Ag,\,\,S-Au,\,\,S-W). A
qualitative prediction for rapidity, transverse kinetic energy and transverse
momenta normalized distributions are performed at 200 GeV/Nucleon in
p-S,S-S,S-Ag and S-Au collisions in comparison with recent experimental data.
HIJING model predictions for coming experiments at CERN for S-Au, S-W and Pb-Pb
interactions are given. The theoretical calculations are estimated in a full
phase space.


title: Semileptonic Decays of Heavy to Light Mesons from an Mit Bag Model

abstract:
  Using the (modified) MIT bag model we calculated formfactors and decay widths
for pseudoscalar - pseudoscalar and pseudoscalar - vector semileptonic decays
of heavy to light mesons. We discuss the physical phenomena which are important
in these processes and their influence on the measurable quantities. Our
results are consistent with the available experimental data. A comparison with
the results of other models is also given.


title: New Predictive Framework for Fermion Masses in SUSY SO(10)

abstract:
  We present a new predictive approach based on SUSY $SO(10)$ theory. The
inter-family hierarchy is first generated in the sector of hypothetical
superheavy fermions and then transfered inversely to ordinary quarks and
leptons by means of the universal seesaw mechanism. The obtained mass matrices
are simply parametrized by two small complex coefficients $\eps_u$ and
$\eps_d$, which can be given by the ratio of the GUT scale $M_G\simeq 10^{16}$
GeV and some higher scale $M\simeq 10^{17}-10^{18}$ GeV (presumably superstring
scale). The model provides a possibility for doublet-triplet splitting without
fine tuning and the Higgsino mediated $d=5$ operators for the proton decay are
naturally suppressed.
  Our ansatz provides the correct {\em qualitative} picture of fermion mass
hierarchy and mixing pattern, provided that $\eps_d/\eps_u\sim 10$. The running
masses of the first family fermions: electron, u-quark and d-quark obey an
approximate $SO(10)$ symmetry limit. At GUT scale we have: $u\sim d\simeq 3e$,
$(\frac{\eps_u}{\eps_d})c\sim s\simeq \frac{1}{3}\mu$ and
$(\frac{\eps_u}{\eps_d})^2t\sim b\simeq \tau$. The Cabibbo angle is large:
$s_{12}\simeq \sqrt{m_d/m_s}$ while other mixing angles have their natural
size: $s_{23}\sim m_s/m_b$ and $s_{13}\sim m_d/m_b$. We have many strong {\em
quantitative} predictions though no special `zero' texture is utilized (in
contrast to the known predictive frameworks). Namely, taking as input the
lepton, c-quark and b-quark masses, $m_s/m_d$ mass ratio and Cabibbo angle, we
can obtain the light (u,d,s) quark masses, top mass and $\tan\beta$. The top
quark is naturally in the 100 GeV range, but not too heavy: $m_t<165$ GeV. The
lower bound $M_t>150$ GeV (160 GeV)


title: Majoron Decay in Matter

abstract:
  It is well known that the matter can significantly alter the picture of
neutrino oscillation \cite{W} or neutrino decay \cite{BV}. Here we show that
the presence of dense matter induces also the decay of {\it massless} majoron,
a Goldstone boson associated with the spontaneous lepton number violation, into
a couple of neutrinos with the same (or in some cases also opposite)
helicities. We calculate the rates of such matter induced majoron decays in
various cases, depending on the neutrino type and the chemical content of the
medium, and analyse their properties.


title: Model independent QED corrections to the process $ep \longrightarrow eX$

abstract:
  We give an exhaustive presentation of the semi-analytical approach to the
model independent leptonic QED corrections to deep inelastic neutral current
lepton-nucleon scattering. These corrections include photonic bremsstrahlung
from and vertex corrections to the lepton current of the order ${\cal
O}(\alpha)$ with soft photon exponentiation. % A common treatment of these
radiative corrections in several variables -- leptonic, hadronic, mixed,
Jaquet-Blondel variables -- has been developed and double differential
cross-sections are calculated. In all sets of variables we use some structure
functions, which depend on the hadronic variables and which do not have to be
defined in the quark parton model. The remaining numerical integrations are
twofold (for leptonic variables) or onefold (for all other variables). For the
case of hadronic variables, all phase space integrals have been performed
analytically. Numerical results are presented for a large kinematical range,
covering fixed target as well as collider experiments at HERA or
LEP$\otimes$LHC, with a special emphasis on HERA physics.


title: Non-Perturbative Analysis of the Coleman-Weinberg Phase Transition

abstract:
  We perform a non-perturbative study of the Coleman-Weinberg phase transition
in scalar QED. Our method permits a consistent treatment of the effective
potential near the origin, a region not accessible to perturbation theory. As a
result, we establish reliably the first order character of the phase transition
for arbitrary values of the scalar coupling.


title:
Renormalon Singularities of the QCD Vacuum Polarization Function to
  Leading Order in $1/N_{f}$

abstract:
  We explicitly determine the residues and orders of all the ultra-violet (UV)
and infra-red (IR) renormalon poles in the Borel plane for the QCD vacuum
polarization function (Adler D-function), to leading order in an expansion in
the number of quark flavours, $N_{f}$. The singularity structure is precisely
as anticipated on general grounds. In particular, the leading IR renormalon is
absent, in agreement with operator product expansion ideas. There is a curious
and unexplained symmetry between the third and higher UV and IR renormalon
residues. We are able to sum up separately UV and IR contributions to obtain
closed form results involving $\zeta$-functions. We argue that the leading UV
renormalon should have a more complicated structure than conventionally
assumed. The disappearance of IR renormalons in flavour-saturated SU($N$) QCD
is shown to occur for $N=3,6$ or 9.


title:
Higgs and Top Quark Masses in the Standard Model without Elementary
  Higgs Boson

abstract:
  In this short note I present a simple calculation of the top quark and Higgs
masses, based on the idea that in the standard model without elementary Higgs,
the fact that the $U(1)_Y$ coupling becomes of the order of unity at the Landau
scale $\lambda$ leads to spontaneous symmetry breaking and generation of
masses.


title: Predictions of noncommutative space-time

abstract:
  An unified structure of noncommutative space-time for both gravity and
particle physics is presented. This gives possibilities of testing the idea of
noncommutative space-time at the currently available energy scale. There are
several arguments indicating that noncommutative space-time is visible already
at the electroweak scale. This noncommutative space-time predicts the top quark
mass m_t \sim 172 GeV, the Higgs mass M_H \sim 241 GeV and the existence of a
vector meson and a scalar, which interact universally with the matter.


title:
Perturbative QCD Corrections to the $Z$ Boson Width and the Higgs Decay
  Rate

abstract:
  Radiative QCD corrections significantly influence the theoretical predictions
for the decay rates of the $Z$ and the Higgs boson. The status of the QCD
calculations to the hadronic $Z$ width is reviewed. The role of mass
corrections from bottom quark final states is emphasized. An estimate of the
theoretical uncertainties is given. New results for quartic mass terms of order
${\cal O}(\alpha_s^2)$ are presented. The impact of secondary radiation of
bottom quarks on the determination of $\Gamma(Z\rightarrow b\bar{b})$ is
discussed. Second order QCD corrections to the partial decay rate
$\Gamma(H\rightarrow b\bar{b})$ are also presented in this talk. A recent
result for the flavour singlet contribution to this quantity is presented. It
includes quark mass effects and completes the otherwise massless calculations
of order $\ordas^2)$.


title:
Consequences of Nuclear Shadowing for Heavy Quarkonium Production in
  Hadron-Nucleus Interactions

abstract:
  We study nuclear shadowing in $J/\psi$ and $\Upsilon$ production in
hadron-nucleus interactions and in nucleus-nucleus collisions at the
Relativistic Heavy Ion Collider and the Large Hadron Collider. %We define the
regions in $x_f$ where nuclear shadowing begins %to set in for \jp\ and \up. As
a consequence of the perturbative $Q^2$-dependence of gluon shadowing, we
predict that $\Upsilon$ production is less suppressed than the $J/\psi$. We
show that antishadowing leads to enhanced \jp\ production at $x_f \lesssim 0$,
an effect reduced for $\Upsilon$ production.


title: Constraints on SUSY-GUT unification from $b\to s\gamma$ decay

abstract:
  The top-quark Yukawa infrared fixed-point solution of the renormalization
group equations, with minimal supersymmetry and GUT unification, defines a
low-energy spectrum of supersymmetric particle masses in terms of a few
GUT-scale parameters assuming universal boundary conditions. We give
predictions in this model for the inclusive $b\to s\gamma$ branching fraction
and investigate the impact of non-universal scalar mass boundary conditions. We
find our results do not depend significantly on the value of the GUT-scale
trilinear coupling $A^G$. The small $\tan \beta $ region favors predictions for
the inclusive $b\to s\gamma$ branching fraction close to that of the Standard
Model value. Nevertheless forthcoming experimental results can eliminate some
regions of the GUT parameter space.


title: The Geometrical Color Optics Of Coherent High Energy Processes

abstract:
  CONTENTS. 1.Introduction, 1.1 QCD ideas to be tested; 2. Coherence phenomena
in QED, 2.1 Charge transparency, 2.2 Charge filtering, 2.3 Charge opacity; 3.
Color transparency in perturbative QCD, 3.1 Coherence length in QCD, 3.2
Bjorken scaling for deep inelastic processes, 3.3 Hard Coherent Diffraction
{}From Nucleons and Nuclei; 4. Soft Diffractive Physics and Color Fluctuations,
4.1 Scattering eigenstates formalism; 4.2 Current information on color
fluctuations in Hadrons, 4.3 Small Size Configurations in Pions, 4.4 Nuclear
inelastic diffraction as evidence for color fluctuations near the average
value, 4.5 Inelastic screening corrections to the total cross sections; 5.
Color transparency in nuclear quasielastic reactions. 5.1 Is a small system
made?, 5.2 Time development, 5.3 Relevant data; 6. Color fluctuations in
nucleons and nucleus-nucleus collisions, 6.1 Color opacity effects, 6.2 Color
fluctuations and central collisions, 6.3 Leading hadron transparency effects in
central collisions.


title: Spin Effects in pp-scattering at difraction range and RHIC energies

abstract:
  The spin effects in nucleon-nucleon scattering are calculated in the
framework of the dynamic model taking into account interactions at large
distances and the strong form factors; the model factorization of the $NN$
amplitude into the spin-dependent hadron-pomeron vertex and high-energy
spinless pomeron is obtained. Theoretical predictions for polarization and
$A_{nn}$ are made for the diffraction range at the RHIC energies.


title: Top Quark Mass and Supersymmetry

abstract:
  We summarize the expectations for the top quark mass in supersymmetric models
and discuss the potential implications of its value measured by the CDF group
in Fermilab.


title: Accuracies of K_{e4} Parameters at Daphne

abstract:
  We estimate the experimental accuracies to which the Ke4 parameters will be
measured at DAPHNE. We consider the accuracies obtainable using asymmetries,
and the maximum likelihood method. We find the current determinations of the
relevant parameters will be improved by a factor of five to ten after a year of
running at the anticipated luminosity of DAPHNE.


title:
Energy-Charge Correlation in the $\pi^+\pi^-\pi^0$ Decay of $K_L$ and of
  Tagged Neutral Kaons

abstract:
  We relate the asymmetries in the charged pions energy in the decay into
$\pi^+\pi^-\pi^0$ of $K_L$ and of the tagged neutral kaons. The former
asymmetry is a given combination of $\Re(\epsilon)$, $\Im(\epsilon)$, and
$|\epsilon'|$. Moreover, the non-violating CP asymmetry allows a test for the
$\chi$PT predictions within the Zel'dovich approach for the final state
interaction.


title: Nonperturbative effects in low energy effective theories of QCD

abstract:
  In this talk I concentrate on the role of chiral symmetry realisation by
spin-1 fields in the low energy QCD effective lagrangian. I assume that chiral
symmetry is nonlinearly realised and that spin-1 fields transform homogeneously
under chiral rotations, which is in sharp contrast to previous works where the
$\rho$ and the $a_1$ mesons were treated as approximate gauge bosons of some
chiral group. I emphasise the role played by four-meson couplings which in our
scheme are essential for the theory to make sense. By requiring the kinetic
energy density of the theory to be bounded from below we find inequalities
relating three- and four-point meson couplings. It is finally shown how the
combination of our analysis and of unitarity requirements naturally leads to a
low-energy phenomenological lagrangian for the nonanomalous sector of $\pi\rho
a_1$ strong interactions.


title: Fluctuations in the Mixed Event Technique

abstract:
  A method for an evaluation of fluctuations in the mixed event technique is
proposed. It is shown, that, generally, the magnitude of the fluctuations is
proportional to $N^{3/4}$, where $N$ is the number of produced events, which
should be compared with $N^{1/2}$ for the case of independent events. The
formula eligible for the use in an analysis of experimental data is provided.


title: Aspects of Supersymmetry at LEP II

abstract:
  We give a short introduction to the concept of low energy supersymmetric
models and their phenomenological predictions. In view of the future LEP II
results we have to parametrize these predictions in a model independent way
without too many simplifying assumptions. The study must therefore include
models with {\it non--universal} soft supersymmetry breaking terms. We show
that such non--universalities might have significant influence on the
properties of these models.


title:
Flow Study in Relativistic Nuclear Collisions by Fourier Expansion of
  Azimuthal Particle Distributions

abstract:
  We propose a new method to study transverse flow effects in relativistic
nuclear collisions by Fourier analysis of the azimuthal distribution on an
event-by-event basis in relatively narrow rapidity windows. The distributions
of Fourier coefficients provide direct information on the magnitude and type of
flow. Directivity and two dimensional sphericity tensor, widely used to analyze
flow, emerge naturally in our approach, since they correspond to the
distributions of the first and second harmonic coefficients, respectively. The
role of finite particle fluctuations and particle correlations is discussed.


title: On the Derivative Expansion at Finite Temperature

abstract:
  In this short note, we indicate the origin of nonanalyticity in the method of
derivative expansion at finite temperature and discuss some of its
consequences.


title:
Anomalous Generation Numbers in SO(10) and Supersymmetric SO(10)
  Unification Theories

abstract:
  One of the interesting features in unification models and supersymmetric
unification models is that the chiral states of quarks and leptons in a family
including a right-handed neutrino can be fitted neatly into a fundamental
spinor representation (f.s) of dimension 16 for the SO(10) gauge group.
However, it is shown in this paper that such a fundamental spinor
representation of SO(10) for Weyl fermions will generate global
(non-perturbative) gauge anomalies (of new type) when restricting to the
$SU(2)\otimes SU(2)\otimes SU(2) \otimes SU(2)$ gauge subgroup. Such an example
is the four SU(2) factors obtained through the reduction of the subgroup
$SU(2)\otimes SO(7)$ of SO(10) with the SO(7) to the three SU(2) factors. The
branching rule in this case is given by $(f.s)\rightarrow (2-1-2-2)\oplus
(2-2-1-2)$ in terms of dimensions. A consistent gauge theory implies the gauge
symmetry in a gauge subgroup, and then needs to be well-defined when
restricting to the gauge subgroup. Consequently, a consistent SO(10) quantum
theory needs to satisfy our selection rule $N_f+N_{mf}=even\geq 4$, namely the
total number of generations with $N_f$ ordinary fermion families and $N_{mf}$
mirror fermion families is even and larger than three, and the three
generations of chiral fermions in this content can not correspond to a
consistent theory. Then we expect that there exist at least one additional
fermion family including a right-handed neutrino or at least one family of
mirror fermions including a left-handed mirror neutrino if SO(10) unification
theory is relevant to our realistic world. The next possibility is to have
total six generations that may subject to stringent


title: A SUSY SO(10) Model with Large $tan \beta$

abstract:
  We construct a supersymmetric SO(10) model with the asymptotic relation
tan$\beta \simeq m_t/m_b$ automatically arising from its structure. The model
retains the significant Minimal Supersymmetric Standard Model predictions for
$sin^2 \theta_w$ and $\alpha_s$ and contains an automatic $Z_2$ matter parity.
Proton decay through $d=5$ operators is sufficiently suppressed. It is
remarkable that no global symmetries need to be imposed on the model.


title: MSSM and Large $tan\beta$ from SUSY Trinification

abstract:
  We construct a supersymmetric model based on the semi-simple gauge group
$SU(3)_c \times SU(3)_L \times SU(3)_R$ with the relation $tan\beta \simeq
m_t/m_b$ automatically arising from its structure. The model below a scale
$\sim 10^{16}$ GeV gives naturally rise just to the minimal supersymmetric
standard model and therefore to the presently favored values for $sin^2
\theta_w$ and $\alpha_s$ without fields in representations higher than the
fundamental.


title:
Determination of $\alpha_s$ and the Nucleon Spin Decomposition Using
  Recent Polarized Structure Function Data

abstract:
  New data on polarized $\mu-p$ and $e-p$ scattering permit a first
determination of $\alpha_s$ using the Bjorken sum rule, as well as higher
precision in determining the nucleon spin decomposition. Using perturbative QCD
calculations to $O(\alpha_s^4)$ for the non-singlet combination of structure
functions, we find $\alpha_s(2.5 GeV^2) = 0.375^{+0.062}_{-0.081}$,
corresponding to $\alpha_s(M_Z^2) =0.122^{+0.005}_{-0.009}$, and using
calculations to $O(\alpha_s^3)$ for the singlet combination we find $\Delta u =
0.83 \pm 0.03$, $\Delta d= -0.43 \pm 0.03$, $\Delta s =-0.10 \pm 0.03$, $\Delta
\Sigma \equiv \Delta u + \Delta d + \Ds = 0.31 \pm 0.07$, at a renormalization
scale $Q^2=10 GeV^2$. Perturbative QCD corrections play an essential role in
reconciling the interpretations of data taken using different targets. We
discuss higher-twist uncertainties in these determinations. The $\Delta q$
determinations are used to update predictions for the couplings of massive Cold
Dark Matter particles and axions to nucleons.


title:
A Further Study of $CP$ Asymmetries in Pure Penguin-induced
  $B^{\pm}_{u}$ Decays

abstract:
  We make a further study of $CP$ asymmetries in the pure penguin-induced decay
modes $B^{-}_{u}\rightarrow K^{(*)0} + K^{(*)-}$ and $B^{-}_{u} \rightarrow
\bar{K}^{(*)0} + (\pi^{-}, \rho^{-}, a^{-}_{1})$ by using the two-loop
renormalization-group-improved effective Hamiltonian and factorization
approximation. Different from the previous results obtained without QCD
corrections, the $CP$ asymmetries in each of the two groups are enhanced and
classified with their respective factorization coefficients. A sum over the
pure penguin modes of each group is proposed to obtain an effective branching
ratio and a {\it weighted-mean} signal of $CP$ violation, which should be
statistically significant for experimental observation.


title: Test of $CPT$ Symmetry in $CP$-violating $B$ Decays

abstract:
  Considering that the existing experimental limit for $CPT$ violation is still
poor, we explore various possible ways to test $CPT$ symmetry in $CP$-violating
$B$ decays at $e^{+}e^{-}$ $B$ factories. We find that it is difficult to
distinguish between the effect of direct $CP$ violation and that of $CPT$
violation in the time-integrated measurements of neutral $B$ decays to $CP$
eigenstates such as $\psi K_{S}$ and $\pi^{+}\pi^{-}$. Instead, a cleaner
signal of small $CPT$ violation may appear in the time-integrated $CP$
asymmetries for a few non-$CP$-eigenstate channels, e.g.,
$B^{0}_{d}/\bar{B}^{0}_{d}\rightarrow D^{\pm}\pi^{\mp}$ and
$\stackrel{(-)}{D}$$^{(*)0}K_{S}$. The time-dependent measurements of $CP$
asymmetries are available, in principle, to limit the size of $CPT$-violating
effects in neutral $B$-meson decays.


title: Gluino Production in Electron-Positron Annihilation

abstract:
  We discuss the pair production of gluinos in electron-positron annihilation
at LEP, in a model with soft supersymmetry breaking, allowing for mixing
between the squarks. In much of the parameter space of the Minimal
Supersymmetric Model (MSSM) the cross section corresponds to a $Z$ branching
ratio above $10^{-5}$, even up to $10^{-4}$. A non-observation of gluinos at
this level restricts the allowed MSSM parameter space. In particular, it leads
to lower bounds on the soft mass parameters in the squark sector.


title: Decoupling of the $\epsilon$-scalar mass in softly broken supersymmetry

abstract:
  It has been shown recently that the introduction of an unphysical
$\epsilon$-scalar mass $\tilde{m}$ is necessary for the proper renormalization
of softly broken supersymmetric theories by dimensional reduction ($\drbar$).
In these theories, both the two-loop $\beta$-functions of the scalar masses and
their one-loop finite corrections depend on $\tilde{m}^2$. We find, however,
that the dependence on $\tilde{m}^2$ can be completely removed by slightly
modifying the \drbar renormalization scheme. We also show that previous \drbar
calculations of one-loop corrections in supersymmetry which ignored the
$\tilde{m}^2$ contribution correspond to using this modified scheme.


title: Some Remarks on the Matching Conditions

abstract:
  We analyze the matching conditions to determine the values that the ${\cal
O}(p^4)$ coefficients of an Effective Chiral Lagrangian take in the Standard
Model in the limit of a large Higgs mass, pointing out a number of subtleties
that appear to have gone unnoticed previously. We apply the resulting Effective
Chiral Lagrangian, including the leading two loop effects, to analyze the most
recent electroweak data assuming $m_{top}=174\pm 10$ GeV.


title: Non-leading Logarithms in Principal Value Resummation

abstract:
  We apply the method of principal value resummation of large
momentum-dependent radiative corrections to the calculation of the Drell Yan
cross section. We sum all next-to-leading logarithms and provide numerical
results for the resummed exponent and the corresponding hard scattering
function.


title: CP violation in the cubic coupling of neutral gauge bosons

abstract:
  We investigate the CP violating form factor of the ZZZ$ and $ZZ\gamma$
vertices in the pair production of $Z^0$ bosons. Useful observables in
azimuthal distributions are constructed to probe $CP$ nonconservation which may
originate from these vertices. A simple Two Higgs Model of $CP$ violation is
used as an illustration.


title: Theoretical Predictions for Pion Polarizabilities

abstract:
  The polarizabilities of the pion have been predicted in several different
theoretical frameworks. The status of these is reviewed.


title: How to Measure Kinetic Energy of the Heavy Quark Inside B Mesons?

abstract:
  We discuss how one can determine the average kinetic energy of the heavy
quark inside heavy mesons from differential distributions in $B$ decays. A new,
so-called third, sum rule for the $b\rightarrow c$ transition is derived in the
small velocity (SV) limit. Using this sum rule and the existing data on the
momentum dependence in the $B\rightarrow D^*$ transition (the slope of the
Isgur-Wise function) we obtain a new lower bound on the parameter $\mu_\pi^2 =
(2M_B)^{-1}\langle B |\bar b (i\vec{D})^2 b |B\rangle $ proportional to the
average kinetic energy of $b$ quark inside $B$ meson. The existing data suggest
$\mu_\pi^2 > 0.4$~GeV$^2$ and (from the ``optical'' sum rule)
$\overline{\Lambda} > 500$ MeV, albeit with some numerical uncertainties.


title: CEBAF at Higher Energies

abstract:
  This report summarizes topics in hadron spectroscopy and production which
could be addressed at CEBAF with an energy upgrade to $E_\gamma=8$ GeV and
beyond. The topics discussed include conventional meson and baryon
spectroscopy, spectroscopy of exotica (especially molecules and hybrids), CP
and CPT tests using $\phi$ mesons, and new detector and accelerator options.


title: Diphoton Production at Hadron Colliders and New Contact Interactions

abstract:
  We explore the capability of the Tevatron and LHC to place limits on the
possible existence of flavor-independent $q \bar q \gamma\gamma$ contact
interactions which can lead to an excess of diphoton events with large
invariant masses. Assuming no departure from the Standard Model is observed, we
show that the Tevatron will eventually be able to place a lower bound of
0.5-0.6 TeV on the scale associated with this new contact interaction. At the
LHC, scales as large as 3-6 TeV may be probed with suitable detector cuts and
an integrated luminosity of $100 fb^{-1}$.


title: High energy Scattering in 2+1 QCD: A Dipole Picture

abstract:
  A dipole picture of high energy scattering is developed in the 2+1
dimensional QCD, following Mueller. A generalized integral equation for the
dipole density with a given separation and center of mass position is derived,
and meson-meson non-forward scattering amplitude is therefore calculated. We
also calculate the amplitude due to two pomeron exchange, and the triple
pomeron coupling. We compare the result obtained by this method to our previous
result based on an effective action approach, and find the two results agree at
the one pomeron exchange level.


title:
The Inclusive Semileptonic Decay Lepton Spectrum from $B \to X e
  \overline{\nu}$

abstract:
  In this talk, we review the QCD calculation of the lepton spectrum from
inclusive semileptonic $B$ decay. We compare this prediction to that of the
ACCMM model. This latter work was done in collaboration with Csaba Csaki.


title: CP Violating Effects in $e^+e^-\rightarrow ZH$ and Their Optimization

abstract:
  We consider the possibilities of testing CP conservation in the process
$e^+e^- \rightarrow ZH$. The easiest is to measure the forward-backward
asymmetry of the $Z$ boson, a nonzero value of which signals CP violation. The
effects of CP violation are predicted in the two Higgs doublet model. We show
here that a choise of optimal observables can improve the possibility of
observing CP violation. Although the number of events is not large, useful
information about CP violating parameters can be extracted.


title: Random and Correlated Phases of Primordial Gravitaional Waves

abstract:
  The phases of primordial gravity waves is analysed in detail within a quantum
mechanical context following the formalism developed by Grishchuk and Sidorov.
It is found that for physically relevant wavelengths both the phase of each
individual mode and the phase {\it difference} between modes are randomly
distributed. The phase {\it sum} between modes with oppositely directed
wave-vectors, however, is not random and takes on a definite value with no rms
fluctuation. The conventional point of view that primordial gravity waves
appear after inflation as a classical, random stochastic background is also
addressed.


title: Effective Lagrangian Approach to Weak Radiative Decays of Heavy Hadrons

abstract:
  Motivated by the observation of the decay $\bar{B}\to \bar{K}^*\gamma$ by
CLEO, we have systematically analyzed the two-body weak radiative decays of
bottom and charmed hadrons. There exist two types of weak radiative decays: One
proceeds through the short-distance $b\to s\gamma$ transition and the other
occurs through $W$-exchange accompanied by a photon emission. Effective
Lagrangians are derived for the $W$-exchange bremsstrahlung processes at the
quark level and then applied to various weak electromagnetic decays of heavy
hadrons. Predictions for the branching ratios of $\bar{B}^0\to D^{*0}
\gamma,~\Lambda_b^0\to\Sigma_c^0\gamma,~\Xi_b^0\to \Xi_c^0\gamma$ and
$\Xi_b^0\to\xip_c^0\gamma$ are given. In particular, we found ${\cal
B}(\bar{B}^0 \to D^{*0}\gamma)\approx 0.9\times 10^{-6}$. Order of magnitude
estimates for the weak radiative decays of charmed hadrons: $~D^0\to
\bar{K}^{*0}\gamma,~\Lambda_c^+\to\Sigma^+\gamma$ and $\Xi_c^0\to\Xi^0\gamma$
are also presented. Within this approach, the decay asymmetry for antitriplet
to antitriplet heavy baryon weak radiative transitions is uniquely predicted by
heavy quark symmetry. The electromagnetic penguin contribution to
$\Lambda_b^0\to\Lambda\gamma$ is estimated by two different methods and its
branching ratio is found to be of order $1\times 10^{-5}$. We conclude that
weak radiative decays of bottom hadrons are dominated by the short-distance
$b\to s\gamma$ mechanism.


title:
On the analytic properties of chiral solitons in the presence of the
  $\omega$--meson

abstract:
  A thorough study is performed of the analytical properties of the fermion
determinant for the case that the time components of (axial) vector fields do
not vanish. For this purpose the non--Hermitian Euclidean Dirac Hamiltonian is
generalized to the whole complex plane. The Laurent series are proven to reduce
to Taylor series for the corresponding eigenvalues and --functions as long as
field configurations are assumed for which level crossings do not occur. The
condition that no level crossings appears determines the radius convergence.
However, the need for regularization prohibits the derivation of an analytic
energy functional because real and imaginary parts of the eigenvalues are
treated differently. Consistency conditions for a Minkowski energy functional
are extracted from global gauge invariance and the current field identity for
the baryon current. Various treatments of the Nambu--Jona--Lasinio soliton are
examined with respect to these conditions. Motivated by the studies of the
Laurent series for the energy functional the Euclidean action is expanded in
terms of the $\omega$--field. It is argued that for this expansion the
proper--time regularization scheme has to be imposed on the operator level
rather than on an expression in terms of the one--particle eigenenergies. The
latter treatment is plagued by the inexact assumption that the Euclidean Dirac
Hamiltonian and its Hermitian conjugate can be diagonalized simultaneously. It
is then evident that approaches relying on counting powers of the
$\omega$--field in the one--particle eigenenergies are


title: The Skyrmion limit of the Nambu--Jona-Lasinio soliton

abstract:
  The special role of the isoscalar mesons ($\sigma$ and $\omega$) in the NJL
soliton is discussed. Stable soliton solutions are obtained when the most
general ansatz compatible with vanishing grand spin is assumed. These solutions
are compared to soliton solutions of a purely pseudoscalar Skyrme type model
which is related to the NJL model by a gradient expansion and the limit of
infinitely heavy (axial-) vector mesons.


title: Semiglobal Alice Strings

abstract:
  We show that in certain theories with topologically trivial quotient space of
spontaneously broken gauge symmetry there can exist topologically stable
strings that carry nonabelian gauge flux. These objects result from the
``accidental'' global degeneracy of the vacuum which makes it topologically
nontrivial.
  In particular, some models contain the semiglobal analog of the Alice
strings.


title: Valencia 93: The Summary of Particle Theory

abstract:
  The International School on Cosmological Dark Matter held in Valencia in the
fall of 1993 was devoted to the interplay of cosmology and particle physics,
with the obvious emphasis on the Dark Matter issue. Here I present the expanded
version of my summary talk regarding the particle physics theory part of the
School.


title: Non-resonant diagrams in radiative four-fermion processes

abstract:
  The complete tree level cross section for $e^+e^- \to e^- \bar\nu_e u \bar{d}
\gamma$ is computed and discussed in comparison with the cross sections for
$e^+e^- \to e^- \bar\nu_e u \bar{d} $ and $e^+e^- \to \bar{u} d u \bar{d}$.
Event generators based on the GRACE package for the non-radiative and radiative
case are presented. Special interest is brought to the effect of the
non-resonant diagrams overlooked so far in other studies. Their contribution to
the total cross section is presented for the LEP II energy range and for future
linear colliders ($\sqrt s$ =500 GeV). Effects, at the W pair threshold, of
order 3\% ($e^- \bar\nu_e u \bar{d}$) and 27\% ($\bar{u} d u \bar{d}$) are
reported. Similar behaviour for the radiative case is shown. At $\sqrt s$ = 500
GeV, the relative contribution of the non-resonant diagrams for the radiative
channel reaches 42.5\%.


title: Baryons with Two Heavy Quarks as Solitons

abstract:
  Using the chiral soliton model and heavy quark symmetry we study baryons
containing two heavy quarks. If there exists a stable (under strong
interactions) meson consisting of two heavy quarks and two light ones, then we
find that there always exists a state of this meson bound to a chiral soliton
and to a chiral anti-soliton, corresponding to a two heavy quark baryon and a
baryon containing two heavy anti-quarks and five light quarks, or a
``heptaquark".


title: Determination of QCD Condensates Without Hadronic Spectra

abstract:
  The bounds on the values of gluon, four-quark and quark-gluon condensates are
derived from the requirement of consistency of the sum rules for various
correlators of the hybrid current $a_{\mu}=g\bar d\gamma_{\rho}\tilde
G_{\rho\mu}u$. The upper bound for the gluon condensate is found to be less
then twice its standard value while for the four-quark condensates the
violation of factorization by a factor 3-4 is allowed. The value of the
quark-gluon condensate is given as a function of $\left<\frac{\alpha_s}{\pi}
G^2\right>$ and $\left<(\bar q\Gamma q)^2\right >$ which for the standard
values yields $m_0^2=0.63~\mbox{GeV}^2$ . Our procedure of simultaneous
solution of a number of sum rules allows the quantitative error analysis and is
appropriate for condensate determination also in other cases.


title: Hints of New Flavor Physics at LEP?

abstract:
  A massive gauge boson coupling to the third family but not lighter families
mixes with the $Z$. The $Z$ partial width to $b\overline{b}$ increases, the
$\tau$ asymmetry parameter increases, the invisible width of the $Z$ decreases,
and $\alpha_s(m_Z)$ decreases, all in a manner consistent with present data.


title:
Possibility of $m_t < M_W + m_b$ for SUSY-type of Two Higgs Doublet
  Model

abstract:
  Allowing for realistic uncertainties in input parameters, we demonstrate that
the present CLEO limit of $5.4\times 10^{-4}$ for inclusive $b\to s\gamma$
decay does not yet fully exclude the $t\to bH^+$ decay possibility in
supersymmetric type of two Higgs doublet models. Combined with direct search
for $t\to bH^+$ via $H^+\to \tau^+\nu$ at the Tevatron, we conclude that
$\tan\beta \sim 1$ is the ``allowed" window for $m_{H^+} < m_t < M_W$. The
possibility becomes excluded, however, {\it if} the CLEO limit is pushed below
$4\times 10^{-4}$.


title: A New Dimensionally Reduced Effective Action for QCD at High Temperature

abstract:
  New terms are derived for the three-dimensional effective action of the
static modes of pure gauge SU(N) at high temperature. In previous works,
effective vertices have been obtained by evaluating diagrams involving 2, 3 or
4 external static gluons with one internal nonstatic loop. I take a somewhat
different approach by making a covariant derivative expansion of the one loop
effective action for the static modes, keeping all terms involving up to six
covariant derivatives. The resulting effective action is manifestly invariant
under spatially dependent gauge transformations and contains new 5- and 6-point
effective vertices.


title: Shell model versus liquid drop model for strangelets

abstract:
  An ansatz for the curvature contribution to the density of states for massive
quarks in a bag is given and shown to reproduce exact mode-filling
calculations. A mass-formula for spherical lumps of 3-flavor quark matter is
derived self-consistently from an asymptotic expansion within the MIT bag
model, taking into account bulk, surface, and curvature contributions. Shell
model calculations are performed for a variety of strange quark masses and bag
constants, and the results shown to match nicely with the asymptotic expansion.


title: Convolution Model for the Structure Functions of the Nucleon

abstract:
  We start from an MIT-bag model calculation which provides information about
the constituent quark distributions in the nucleon. The constituent quarks,
however, are themselves considered as complex objects whose partonic
substructure is resolved in deep inelastic scattering. This gives rise to
structure functions of the constituent quarks which, in the unpolarized case,
are fitted to data at a fixed scale employing three model parameters. Using
$Q^{2}$--evolution equations the data are also well described at other scales.
For the spin\-dependent struc\-ture func\-tions $g_{1}^{p,n}$ we additionally
have to introduce polar\-izat\-ion functions for valence and sea quarks which
are determined by exploiting the $x$--dependence of the available proton data
only. A negatively polarized sea in the range $x\geq 0.01$ is suggested. We are
then capable of predicting the shape of the neutron structure function
$g_{1}^{n}$ which turns out to be in good agreement with experiment. Finally we
present an estimate for the trans\-versely polarized structure function
$g_{2}$, offering the possibility of extrac\-ting the twist--3 con\-tri\-bution
and rating its importance.


title:
An Overview of the $\epsilon$ Expansion and the Electroweak Phase
  Transition

abstract:
  Talk presented at the NATO Advanced Workshop on Electroweak Physics and the
Early Universe: Sintra, Portugal, 1994. I summarize work done with Larry Yaffe
on applying $\epsilon$ expansion techniques to the electroweak phase
transition.


title: Determination of Leptoquark Properties in Polarized $e\gamma$ Collisions

abstract:
  We study leptoquark production using polarized $e\gamma$ colliders for the
center of mass energies $\sqrt s=500$~GeV and 1~TeV. We show that using
polarization asymmetries the ten different types of leptoquarks listed by
Buchm\"uller, R\"uckl and Wyler can be distinquished from one another for
leptoquark masses essentially up to the kinematic limit of the respective
colliders. Thus, if a leptoquark were discovered an $e\gamma$ collider could
play a crucial role in determining its origins.


title: Testing J/psi Production and Decay Properties in Hadronic Collisions

abstract:
  The polar and azimuthal angular distributions for the lepton pair arising
from the decay of a J/psi meson produced at transverse momentum p_T balanced by
a photon [or gluon] in hadronic collisions are calculated in the color singlet
model (CSM). It is shown that the general structure of the decay lepton
distribution is controlled by four invariant structure functions, which are
functions of the transverse momentum and the rapidity of the J/psi. We found
that two of these structure functions [the longitudinal and transverse
interference structure functions] are identical in the CSM. Analytical and
numerical results are given in the Collins-Soper and in the Gottfried-Jackson
frame. We present a Monte Carlo study of the effect of acceptance cuts applied
to the leptons and the photon for J/psi+ gamma production at the Tevatron.


title: Pentaquark Search with Energetic Hadron Beams

abstract:
  The strange-anticharmed Pentaquark is a uud(cbar)s or udd(cbar)s five-quark
baryon that is expected to be either a narrow resonance, or possibly even
stable against strong decay. We describe this hyperon here; its structure,
binding energy and lifetime, resonance width, production mechanisms and decay
modes. We estimate production cross sections, techniques to reduce backgrounds
in search experiments, and how to optimize experiments to observe it.
Possibilities for enhancing the signal over background in Pentaquark searches
are investigated by examining predictions for detailed momentum and angular
distributions in multiparticle final states. General model-independent
predictions are presented as well as those from two models: a loosely bound
Ds-N "deuteron" and a strongly-bound five-quark model. Fermilab E791 data,
currently being analysed, may be marginal for showing definitive signals.
Future experiments with more than 10^5 reconstructed charmed baryon events
should have sensitivity to determine whether or not the Pentaquark exists.


title: Photon Structure: QCD Treatment and Parton Densities

abstract:
  The QCD treatment of the photon structure beyond the leading order is
discussed with emphasis on a proper choice of the factorization scheme and/or
the boundary conditions. Recent parametrizations of the photon's parton content
are examined and compared. The sensitivity of the photon structure function on
the QCD scale parameter is reconsidered.


title: Pion Mass Effects in the Large $N$ Limit of $\chiPT$

abstract:
  We compute the large $N$ effective action of the $O(N+1)/O(N)$ non-linear
sigma model including the effect of the pion mass to order
$m^2_{\pi}/f_{\pi}^2$. This action is more complex than the one corresponding
to the chiral limit not only because of the pion propagators but also because
chiral symmetry produce new interactions proportional to $m^2_{\pi}/f_{\pi}^2$.
We renormalize the action by including the appropriate counter terms and find
the renormalization group equations for the corresponding couplings. Then we
estudy the unitarity propierties of the scattering amplitudes. Finally our
results are applied to the particular case of the linear sigma model and also
are used to fit the pion scattering phase shifts.


title: Cosmological Constraints on the Scale of Supersymmetry Breaking

abstract:
  We consider the cosmological and astrophysical constraints on the decay of
massive $E_8 \times E_8^\prime$ superstring axions associated with the hidden
sector. We find that decay lifetimes greater than 1 s are ruled out by limits
from nucleosynthesis, by limits on the distortion of the cosmic microwave and
gamma ray backgrounds and by closure arguments. We conclude that
$\Lambda>1.2\times10^{13}\gev$, where $\Lambda$ is the scale of gaugino
condensation in the hidden sector. This implies that the scale of supersymmetry
breaking is greater than $10^{10}\gev$. Significantly, our result agrees with
the value of $5\times 10^{13}\gev$ for $\L$ obtained independently by setting
supersymmetric scalar masses equal to $m_W$.


title: Constraints on Baryogenesis from the Decay of Superstring Axions

abstract:
  We calculate the dilution of the baryon-to-photon ratio by the decay of
superstring axions. We find that the dilution is of the order of $10^7$. We
review several models of baryogenesis and show that most of them can not
tolerate such a large dilution. In particular, only one current model of
electroweak baryogenesis possibly survives. The Affleck-Dine mechanism in SUSY
GUTs is very robust and the dilution by axions could contribute to the dilution
required in these models. Baryogenesis scenarios involving topological defects
and black hole evaporation are also capable of producing a sufficiently large
baryon asymmetry.


title: Naturally Light Leptoquarks

abstract:
  Light first generation leptoquarks are being hunted for in HERA and at FNAL
and there are various proposals for further searches in future machines. Such
leptoquarks are however problematic from a theoretical point of view: Low
energy precision measurements imply strong constraints on the couplings of the
leptoquarks, and up till now the fulfilment of these constraints seemed
extremely unnatural. Here we show that horizontal symmetries, which are very
conventional and widely used in the literature for completely different
purposes, can suppress the unwanted couplings. Therefore light first generation
leptoquarks can be natural.


title: Clan Structure Analysis and Rapidity Gap Probability

abstract:
  Clan structure analysis in rapidity intervals is generalized from negative
binomial multiplicity distribution to the wide class of compound Poisson
distributions. The link of generalized clan structure analysis with correlation
functions is also established. These theoretical results are then applied to
minimum bias events and evidentiate new interesting features, which can be
inspiring and useful in order to discuss data on rapidity gap probability at
TEVATRON and HERA.


title: Dynamical Scenarios for $SU(2)_c$ Symmetric New Physics Interactions

abstract:
  We study a picture of effective interactions among the $W$ and Higgs bosons
which is consistent with the precision tests at present energies, and at the
same time allows for large observable New Physics (NP) effects in the bosonic
sector. Toy dynamical models containing new heavy particles are used to
indicate how such a picture could be created by integrating out the heavy
particles. In these models custodial $SU(2)_c$ symmetry is realized at a
certain large scale $\Lambda_{NP}$, either naturally or at a certain limit of a
single coupling. In the derivation of the effective lagrangian we keep
operators of dimension up to six. These operators involve only the known gauge
boson and Higgs particles. They provide a valid description of NP up to an
energy scale which is just below the mass of the new heavy degrees of freedom.


title:
Momentum Dependent Vertices $\sigma \gamma \gamma$, $\sigma \rho \gamma$
  and $\sigma \rho \rho$ : The NJL Scalar Hidden by Chiral Symmetry

abstract:
  We calculate the momentum dependence of three particle vertices $\sigma
\gamma \gamma$, $\sigma \rho \gamma$ and $\sigma \rho \rho$ in the context of a
Nambu Jona Lasinio type model. We show how they influence the processes $\gamma
\gamma \rightarrow \sigma \rightarrow \pi \pi$, $\rho \rightarrow \gamma
\sigma$ and $\gamma \gamma \rightarrow \rho \rho$ and how chiral symmetry
shadows the presence of the $\sigma$.


title:
Limits on Associated Production of Visibly and Invisibly Decaying Higgs
  Bosons from Z Decays

abstract:
  Many extensions of the standard electroweak model Higgs sector suggest that
the main Higgs decay channel is "invisible", for example, $h \to J J$ where $J$
denotes the majoron, a weakly interacting pseudoscalar Goldstone boson
associated to the spontaneous violation of lepton number. In many of these
models the Higgs boson may also be produced in association to a massive
pseudoscalar boson (HA), in addition to the standard Bjorken mechanism (HZ). We
describe a general strategy to determine limits from LEP data on the masses and
couplings of such Higgs bosons, using the existing data on acoplanar dijet
events as well as data on four and six $b$ jet event topologies. For the sake
of illustration, we present constraints that can be obtained for the ALEPH
data.


title:
Exact Multiparticle Amplitudes at Threshold in $\phi^4$ Theories with
  Softly Broken $O(\infty)$ Symmetry

abstract:
  We consider the problem of multiparticle production at threshold in a
$\phi^4$-theory with an $O(N_1$$+$$N_2)$ symmetry softly broken down to
$O(N_1)\times O(N_2)$ by nonequal masses. We derive the set of recurrence
relations between the multiparticle amplitudes which sums all relevant diagrams
with arbitrary number of loops in the large-$N$ limit with fixed number of
produced particles. We transform it into a quantum mechanical problem and show
how it can be obtained directly from the operator equations of motion by
applying the factorization at large $N$. We find the exact solutions to the
problem by using the Gelfand--Diki\u{\i} representation of the diagonal
resolvent of the Schr\"{o}dinger operator. The result coincides with the tree
amplitudes while the effect of loops is the renormalization of the coupling
constant and masses. The form of the solution is due to the fact that the exact
amplitude of the process $2$$\ra$$n$ vanishes at $n$$>$$2$ on mass shell when
averaged over the $O(N_{1,2})$-indices of incoming particles. We discuss what
dynamical symmetry is behind this property. We also give an exact solution in
the large-$N$ limit for the model of the $O(N)$$+$$singlet$ scalar particle
with the spontaneous breaking of a reflection symmetry.


title:
Heavy Quark Effective Theory, Interpolating Fields and Bethe-Salpeter
  Amplitudes

abstract:
  We use the LSZ reduction theorem and interpolating fields, alongwith the
heavy quark effective theory, to investigate the structure of the
Bethe-Salpeter amplitude for heavy hadrons. We show how a simple form of this
amplitude, used extensively in heavy hadron decay calculations, follows
naturally upto $O(1/M)$ from these field theoretic considerations.


title: Experimental signatures of a massive mirror photon

abstract:
  There has been some speculation about the possible existence of a second
photon which only couples to ordinary matter through mixing of the gauge
kinetic terms. If the exotic photon is massless, then the principle
phenomenological effect of the kinetic mixing is to give the mirror particles
small electric charges (mini-charged particles). We examine the possibility
that the exotic photon is massive. In this case the experimental signatures of
the mirror photon are quite different to the case when the exotic photon is
massless. In this scenario you do not get mini charged fermions but instead you
can get processes directly producing the mirror photon such as Compton-like
scattering: $e+\gamma \rightarrow e + \gamma^m$ (where $e, \gamma, \gamma^m$
denote the electron, photon and mirror photon respectively).


title: Multiplicity Distributions and Rapidity Gaps

abstract:
  I examine the phenomenology of particle multiplicity distributions, with
special emphasis on the low multiplicities that are a background in the study
of rapidity gaps. In particular, I analyze the multiplicity distribution in a
rapidity interval between two jets, using the HERWIG QCD simulation with some
necessary modifications. The distribution is not of the negative binomial form,
and displays an anomalous enhancement at zero multiplicity. Some useful
mathematical tools for working with multiplicity distributions are presented.
It is demonstrated that ignoring particles with pt<0.2 has theoretical
advantages, in addition to being convenient experimentally.


title: Three generation vacuum oscillations and the solar neutrino problem

abstract:
  We investigate the solar neutrino problem in the scenario of three generation
neutrino oscillation hypothesis, taking into account other phenomenological
constraints to the neutrino mixing and mass parameters.


title: "TRIVIALITY" MADE EASY: the real (lambda Phi^4)_4 story

abstract:
  The real meaning of `triviality' of (lambda Phi^4)_4 theory is outlined.
Assuming `triviality' leads to an effective potential that is just the
classical potential plus the zero-point energy of the free-field fluctuations.
This V_{eff} gives spontaneous symmetry breaking. Its proper renormalization
has the consequence that all scattering amplitudes vanish, self-consistently
validating the original assumption. Nevertheless, the theory is physically
distinguishable from a free field theory; it has a symmetry-restoring phase
transition at a finite critical temperature.


title: Radiative Corrections to P-Levels in the Two-Body QED Problem

abstract:
  The physical origin of the $m\alpha^5$ radiative corrections to $P$-levels in
the two-body QED problem is elucidated. Then we demonstrate that the next
order, $m\alpha^6$, corrections to those levels are due to the anomalous
magnetic moment only.


title: A nonlocal, covariant generalisation of the NJL model

abstract:
  We solve a nonlocal generalisation of the NJL model in the Hartree
approximation. This model has a separable interaction, as suggested by
instanton models of the QCD vacuum. The choice of form factor in this
interaction is motivated by the confining nature of the vacuum. A conserved
axial current is constructed in the chiral limit of the model and the pion
properties are shown to satisfy the Gell-Mann--Oakes--Renner relation. For
reasonable values of the parameters the model exhibits quark confinement.


title: Dijet Production at HERA as a Probe of BFKL Dynamics

abstract:
  We calculate the rate for the deep-inelastic electroproduction of dijets at
HERA. We study the weakening of the azimuthal (back-to-back) correlation
between the jets, as $x$ decreases, to see whether it can be used to identify
BFKL dynamics from conventional fixed-order QCD effects. We show how this may
give information on the transverse momentum ($k_T)$ dependence of the gluon
distribution of the proton.


title: Radiation of Heavy Quarks

abstract:
  The rate for the production of massive fermions radiated off a pair of
massless fermions is calculated analytically. Combined with the analytic
calculation of the corresponding virtual contribution one obtains the order
$\alpha^2$ correction to the cross section which is induced by the real and
virtual radiation of a pair of massive fermions by massless fermions.
Approximations valid for large and for small masses are derived and shown to
agree with earlier calculations.


title:
Rigorous QCD Analysis of Inclusive Annihilation and Production of Heavy
  Quarkonium

abstract:
  A rigorous QCD analysis of the inclusive annihilation decay rates of heavy
quarkonium states is presented. The effective-field-theory framework of
nonrelativistic QCD is used to separate the short-distance scale of
annihilation, which is set by the heavy quark mass $M$, from the
longer-distance scales associated with quarkonium structure. The annihilation
decay rates are expressed in terms of nonperturbative matrix elements of
4-fermion operators in nonrelativistic QCD, with coefficients that can be
computed using perturbation theory in the coupling constant $\alpha_s(M)$. The
matrix elements are organized into a hierarchy according to their scaling with
$v$, the typical velocity of the heavy quark. An analogous factorization
formalism is developed for the production cross sections of heavy quarkonium in
processes involving momentum transfers of order $M$ or larger. The
factorization formulas are applied to the annihilation decay rates and
production cross sections of S-wave states, up to corrections of relative order
$v^3$, and of P-wave states, up to corrections of relative order $v^2$.


title: HQET and Inclusive Decays of Heavy Hadrons

abstract:
  We discuss the recent developments in inclusive decays of hadrons containing
a heavy quark. The subject is approached in a model independent way using an
operator product expansion for the time-ordered product of weak currents. We
discuss the extraction of the weak mixing angle $|V_{cb}|$ from inclusive
semileptonic $B$ decays and the application of these techniques to the endpoint
of the $e^-$ spectrum in $B\rightarrow X_ue\nu$. We also suggest that the
comparison of inclusive semileptonic widths for $D_s$ and $D$ mesons will give
an indication of the consistency of this approach in charm decays. \bigskip
{\it Invited talk presented at the "Intersections of Particle and Nuclear
Physics" conference, St Petersburg, Florida, 31 May to 6 June, 1994.}


title: Helicity Probabilities For Heavy Quark Fragmentation Into Excited Mesons

abstract:
  In the fragmentation of a heavy quark into a heavy meson whose light degrees
of freedom have angular momentum $3/2$, all the helicity probabilities are
completely determined in the heavy quark limit up to a single probability
$w_{3/2}$. We point out that this probability depends on the longitudinal
momentum fraction $z$ of the meson and on its transverse momentum $p_\bot$
relative to the jet axis. We calculate $w_{3/2}$ as a function of scaling
variables corresponding to $z$ and $p_\bot$ for the heavy quark limit of the
perturbative QCD fragmentation functions for $b$ quark to fragment into $(b
\bar c)$ mesons. In this model, the light degrees of freedom prefer to have
their angular momentum aligned transverse to, rather than along, the jet axis.
Implications for the production of excited heavy mesons, like $D^{**}$ and
$B^{**}$, are discussed.


title:
Parity Violating Longitudinal Muon Polarization in
  $K^+\to\pi^+\mu^+\mu^-$ Beyond Leading Logarithms

abstract:
  We generalize the existing analyses of the parity violating muon polarization
asymmetry $\Delta_{LR}$ in $K^+\to\pi^+\mu^+\mu^-$ beyond the leading
logarithmic approximation. The inclusion of next--to--leading QCD corrections
reduces the residual dependence on the renormalization scales, which is quite
pronounced in the leading order. This leads to a considerably improved accuracy
in the perturbative calculation of the short distance dominated quantity
$\Delta_{LR}$. Accordingly this will also allow to obtain better constraints on
the Wolfenstein parameter $\varrho$ from future measurements of $\Delta_{LR}$.
For $-0.25\leq \varrho \leq 0.25$, $V_{cb}=0.040\pm 0.004$ and $m_t=(170\pm
20)GeV$ we find $3.0\cdot 10^{-3}\leq |\Delta_{LR}|\leq 9.6\cdot 10^{-3}$.


title:
Renormalization Scheme Dependence and the Problem of Theoretical
  Uncertainties in Next-Next-to-Leading Order QCD Predictions

abstract:
  Renormalization scheme uncertainties in the next-next-to-leading order QCD
predictions are discussed. To obtain an estimate of these uncertainties it is
proposed to compare predictions in all schemes that do not have unnaturally
large expansion coefficients. A concrete prescription for eliminating the
unnatural schemes is given, based on the requirement that large cancellations
in the expression for the characteristic renormalization scheme invariant
should be avoided. As an example the QCD corrections to the Bjorken sum rule
are considered. The importance of the next-next-to-leading order corrections
for a proper evaluation of perturbative QCD predictions is emphasized.


title: Infrared factorization in inclusive B meson decays

abstract:
  We perform infrared factorization of differential rates of radiative and
semileptonic inclusive decays of the B meson in the end-point region of photon
and charged lepton spectrum, respectively, in the leading heavy quark mass
limit. We find that the differential rates are expressed in terms of hard, jet
and soft functions, which satisfy evolution equations. Solving these equations,
we find expressions for the moments of the differential rates in their
end-point regions, which take into account all leading and nonleading
logarithmic corrections in perturbation theory, as well as large
nonperturbative power corrections. Expanded to the one-loop level, our
predictions coincide with the results of existing lowest order calculations for
B->\gamma X_s and B->l\barnu X_u. Nonperturbative corrections appear in our
formalism from the boundary value of the soft function in the evolution
equation. The soft function is a universal process-independent function, which
describes the distribution of the b quark in the B meson. Its behavior in the
end-point region is governed by the nonperturbative asymptotics of a Wilson
line expectation value. By considering the contributions of infrared
renormalons, we find an ansatz for the Wilson line, which leads to a Gaussian
model for the heavy quark distribution function.


title:
Probing the Heavy Quark Content of the Photon Using b Tagging at
  Electron Photon Colliders

abstract:
  We study the prospects for probing the quark content of the photon using b
tagging at high energy electron-photon colliders. We find that heavy quark
tagging provides a sensitive and effective probe of the quark content of the
photon. Using a 500 GeV $e^+e^-$\ NLC in electron-photon mode, the cross
section for $eb_{\gamma}\rightarrow eb$\ can be measured to 10\% with b
tagging. This is sufficient to differentiate between the various photon
structure functions.


title: Non-Zero Electric Charge of the Neutrino and the Solar Neutrino Problem

abstract:
  It has recently been shown that the neutrino can have non-zero electric
charge in a number of gauge theories, including the Minimal Standard Model.
Assuming non-zero neutrino charge, we develop a new approach to the solar
neutrino problem. The key idea is that the charged neutrinos will be deflected
by the Lorentz force while they are crossing the solar magnetic fields. Such a
deflection will result in the anisotropy of the solar neutrino flux. Because of
this anisotropy, the solar neutrino flux registered on earth can be reduced as
compared to the Standard Solar Model prediction. The mechanism is purely
classical and does not require neutrino oscillations, spin-flip or neutrino
decay. We discuss qualitatively the consequences of our scenario for present
and future solar neutrino experiments as well as differences between our
mechanism and other proposed solutions.


title: Next-to-Leading Order Fragmentation Functions for Pions and Kaons

abstract:
  We present new sets of fragmentation functions for charged pions and kaons,
both at leading and next-to-leading order. They are fitted to TPC data taken at
energy $\sqrt s=29$~GeV and describe excellently a wealth of other $e^+e^-$
data on charged-hadron production, ranging from $\sqrt s=5.2$~GeV way up to
LEP~1 energy. They also agree with data on the production of neutral pions and
kaons, if one makes the natural assumption that the respective fragmentation
functions are related to the charged counterparts by SU(2) symmetry. We also
list simple parameterizations of the $x$ and $Q^2$ dependence of our results,
which may be implemented conveniently in applications.


title:
Probing the Heavy Quark Content of the Photon Using b Tagging at High
  Energy $e\gamma$ and $e^+e^-$ Colliders

abstract:
  We suggest a method for probing the quark content of the photon using $b$
tagging at high energy $e^+e^-$ and $e\gamma$ colliders. We find that heavy
quark tagging provides a sensitive and effective probe of the quark content of
the photon especially in the low $x$-region where the various models differ the
most. This process is complementary to others that have been studied in the
literature and can contribute to more precise determinations of quark and gluon
distributions inside the photon.


title:
On the Choice of Dispersion Relation to Calculate the QCD Correction to
  $\Gamma(H\to \ell^+\ell^-)

abstract:
  We use the Operator Product Expansion (OPE) of quark vacuum polarization
functions to show that the dispersion relation of Kniehl and Sirlin will yield
the correct result to all orders in $\alpha_s$ when applied to the QCD
correction to the leptonic decay width of the Higgs boson.


title: Gauge independent Chiral Symmetry Breaking in Quenched QED

abstract:
  In quenched QED we construct a non-perturbative fermion-boson vertex that
ensures the fermion propagator satisfies the Ward-Takahashi identity, is
multiplicatively renormalizable, agrees with perturbation theory for weak
couplings and has a critical coupling for dynamical mass generation that is
strictly gauge independent. This is in marked contrast to the rainbow
approximation in which the critical coupling changes by 50% just between the
Landau and Feynman gauges. The use of such a vertex should lead to a more
believable study of mass generation.


title: Neutrinos From Particle Decay in the Sun and Earth

abstract:
  Weakly interacting massive particles (WIMPs) may be indirectly detected by
observation of upward muons induced by energetic neutrinos from annihilation of
WIMPs that have accumulated in the Sun and/or Earth. Energetic muon neutrinos
come from the decays of $\tau$ leptons, $c$, $b$, and $t$ quarks, gauge bosons,
and Higgs bosons produced by WIMP annihilation. We provide analytic
expressions, suitable for computing the flux of upward muons, for the neutrino
energy spectra from decays of all these particles in the center of the Sun and
Earth. These analytic expressions should obviate the need for Monte Carlo
calculations of the upward-muon flux. We investigate the effects of
polarization of the gauge bosons on the neutrino spectra and find that they are
small. We also present simple expressions for the second moments of the
neutrino distributions which can be used to estimate the rates for observation
of neutrino-induced muons from WIMP annihilation.


title:
Instanton--Antiinstanton pair induced Asymptotics of Perturbation Theory
  in QCD

abstract:
  The instanton--antiinstanton pair induced asymptotics of perturbation theory
expansion for QCD correlators is considered. It is argued that though the true
asymptotics is dominated by renormalon, the instanton-induced contribution may
dominate in the intermediate asymptotics $n= 5\div 15$.
  Obtained asymptotic formulae are valid for $N_f \le N_c$. For $N_f =N_c$ the
finite nonperturbative expression for instanton--antiinstanton contribution was
also found.
  At $q^2<0$ the imaginary part of correlators in the case $N_f =N_c$ is
suppressed like $1/\log (q/\Lambda)$, but the present accuracy of instanton
calculations allows to fix it unambiguously.
  The series of corrections to the instanton induced asymptotics of the order
of $\sim (\log(n)/n)^k$ is found.


title: Calculation of the D and B Meson Lifetimes

abstract:
  Using the expansions of the heavy meson decay widths in the heavy quark mass
and QCD sum rules for estimates of corresponding matrix elements,\, we
calculate the $D^{\pm,o,s}$ decay widths and the $B^{\pm,o,s}$ lifetime
differences. The results for D mesons are in agreement with the data,\, while
it is predicted that $[\Gamma (B^o)-\Gamma (B^-)]/\Gamma_B\se 4\%\,,$ and the
lifetime difference of the $B^o$ and $B_s$ mesons is even smaller. The role of
the weak annihilation and Pauli interference contributions to the lifetime
differences are described in detail. In the course of self-consistent
calculations the values of many parameters crucial for calculations with
charmed and beauty mesons are found. In particular,\, the perturbative pole
quark masses are: $M_c\se 1.65\,GeV,\,\, M_b\se 5.04\,GeV\,,$ and the decay
constants are: $f_D(M_c)\se 165\,MeV\,,\,\,f_B(M_b)\se 113\,MeV\,$. It is also
shown that the nonfactorizable corrections to the $B^o-{\bar B}^o$ mixing are
large,\, $B_B\se (1-18\%)\,.$ The values of the unitarity triangle parameters
are found which are consistent with these results and the data available
(except for the NA31 result for the $\epsilon ^{\prime}/\epsilon$ which is too
large): $\lambda\se 0.22\,,\,\, A\se 0.825\,,\,\,\rho \se -0.4\,,\,\, \eta \se
0.2\,.$


title: Vanishing condensates and anomalously light Goldstone modes in medium

abstract:
  We show that in a uniform medium, the vanishing of a particular condensate
along with spontaneously broken symmetry imply the existence of an anomalously
light pseudo-Goldstone mode. The consequences for a vanishing chiral condensate
in nuclear matter are discussed.


title: Condensation and Magnetization of the Relativistic Bose Gas

abstract:
  We present a simple proof of the absence of Bose--Einstein condensation of a
relativistic boson gas, in any finite local magnetic field in less than five
dimensions. We show that the relativistic charged boson gas exhibit a genuine
Meissner--Ochsenfeld effect of the Schafroth form at fixed supercritical
density. As in the well--known non--relativistic case, this total expulsion of
a magnetic field is caused by the condensation of the Bose gas at vanishing
magnetic field. The result is discussed in the context of kaon condensation in
neutron stars.


title: Thermal Versus Vacuum Magnetization in QED

abstract:
  The magnetized relativistic Fermi and Bose gases are studied at finite
temperature and density.In the case of the Fermi gas, the contribution to the
magnetization from the vacuum becomes dominant for high magnetic fields, when
the thermal contribution saturates.
  In the case of the charged Bose gas, the (paramagnetic) vacuum--magnetization
becomes dominant when the gas changes from a diamagnetic to a paramagnetic
behaviour. We furthermore find that the scalar--QED effective coupling constant
for a weak non--zero external magnetic field is a decreasing function of the
temperature.


title: Higgs Mass Bounds Separate Models of Electroweak Symmetry Breaking

abstract:
  Vacuum stability implies a lower limit on the mass of the higgs boson in the
Standard Model (SM). In contrast, an upper limit on the lightest higgs mass can
be calculated in supersymmetric (susy) models. The main uncertainty in each
limit is the value of the top mass, which may now be fixed by the recent CDF
result. We study the possibility that these bounds do not overlap, and find
that (i) a mass gap emerges at $m_t\sim 160$ GeV between the SM and the Minimal
Susy Standard Model (MSSM); and between the SM and the Minimal plus Singlet
Susy Model [(M+1)SSM] if the independent scalar self--coupling of the latter is
perturbatively small or if the $\tan\beta$ parameter is large; this gap widens
with increasing $m_t$; (ii) there is no overlap between the SM and the MSSM
bounds at even smaller values of $m_t$ for the $\tan\beta$ value ($\sim 1$--2)
preferred in Supersymmetric Grand Unified Theories. Thus, if the new top mass
measurement remains valid, a measurement of the first higgs mass will serve to
exclude either the SM or MSSM/(M+1)SSM higgs sectors. In addition, we discuss
the upper bound on the lightest higgs mass in susy models with an extended
higgs sector, and in models with a strongly interacting higgs sector. Finally,
we comment on the discovery potential for the lightest higgses in these models.


title: Scalar three-body decays and signals for new physics

abstract:
  If massive invisible particles are pair-produced in a three-body decay, then
the energy distribution of the other (visible) product is sensitive to the mass
of the invisible pair. We use this fact in the context of a Higgs boson
decaying into (i)a Z-boson and two massive neutrinos of a fourth generation,
and (ii)a Z and two lightest particles in the minimal supersymmetric standard
model. We discuss how the Z-energy spectrum in each case can reflect the values
of the parameters in such models. (3 figures, hard copies available from
authers on request).