title: Quark Fragmentation into ^3P_J Quarkonium

abstract:
  We calculate the functions of parton fragmentation into $^3P_J$ quarkonium at
order $\alpha_s ^2$, where the parton can be a heavy or light quark. The
obtained functions explicitly satisfy the Altarelli-Parisi equation and they
are divergent, behaving as $z^{-1}$ near $z=0$. However, if one choses the
renormalization scale as twice of the heavy quark mass, the fragmentation
functions are regular over the whole range of $z$.


title: Triality in QCD at Zero and Finite Temperature: A New Direction

abstract:
  Discrete symmetries in grand canonical ensembles and in ensembles canonical
with respect to triality are investigated. We speculate about the general phase
structure of finite temperature gauge theories with discrete $Z(N)$ symmetry.
Low and high temperature phases turn out to be different in both ensembles even
for infinite systems. It is argued that gauge theories with matter fields in
the fundamental representation should be treated in ensembles canonical with
respect to triality if one wants to avoid unphysical predictions. Further, we
discuss as a physical consequence of such a treatment the impossibility of the
existence of metastable phases in the quark-gluon plasma.


title:
Particle Currents on a CP Violating Higgs Background and the Spontaneous
  Baryogenesis Mechanism

abstract:
  We compute the particle currents induced on a bubble wall background at
finite temperature in a model with CP violation in the Higgs sector. Using a
field theory approach we show that fermionic currents arise at one loop, so
that a suppression factor ${\cal O}(h_t \phi/\pi T)^2$ with respect to previous
computations is found. The contributions to the Higgs currents are also derived
and their relevancy for the spontaneous baryogenesis mechanism is discussed.


title: Thermal Green Functions at Zero Energy

abstract:
  The thermal expectation values of all possible bosonic generalised retarded
functions evaluated at zero energy are studied. The relationship of such
functions to calculational schemes, technical problems and physical
applications is outlined. It is then shown that all generalised retarded
functions constructed from any one set of bosonic fields are equal at zero
energy. This is done completely generally and is not limited to any
approximation scheme such as perturbation theory.


title: WEAK TRANSITIONS OF HEAVY MESONS AND THE QUARK MODEL

abstract:
  We underline the general features of the constituent quark model and its
success in the description of the spectrum and transitions of hadrons made up
of light or heavy quarks, briefly compared to first principles of QCD. To show
the present usefulness of the techniques and intuitive insight of the model we
present a semirelativistic quark model of meson form factors that exhibits
Isgur-Wise scaling and corrections to it. As examples of applications, we
consider semileptonic form factors and non-leptonic decays of heavy flavor
mesons. We address the issue of the violation of factorization, and show how
the quark model can give hints on the problem.


title:
Strangeness in constituent quarks and one-spin asymmetry in inclusive
  $\varphi$-meson production

abstract:
  On the basis of the mechanism proposed earlier for one-spin asymmetries in
inclusive hadron production we consider OZI--suppressed process of
$\varphi$-meson production $pp\rightarrow \varphi X$ and asymmetry
$A_N(\varphi)$ in this process. The main role in generation of this asymmetry
belongs to the orbital angular momentum of strange quark-antiquark cloud in
internal structure of constituent quarks.


title: Theoretical Progress in K and B Decays

abstract:
  We review several aspects of the recent theoretical progress in K and B
decays including the impact of the top quark discovery on rare and CP violating
decays. In particular we summarize the present status of next-to-leading QCD
calculations in this field stressing their importance in the determination of
the parameters in the Cabibbo-Kobayashi-Maskawa matrix.


title: MIXING AND CP VIOLATION IN D MESONS

abstract:
  We review mixing and CP violation in $D$ mesons, emphasizing the differences
with the other pseudoscalar mesons in the Standard Model, and show that $D$
mesons can be useful to look for physics beyond the Standard Model.


title: An Introduction to Lattice QCD

abstract:
  Lattice QCD is the only non-perturbative method based uniquely on the first
principles of QCD. After a very simple introduction to the principles of
lattice QCD, I discuss its present limitations and the type of processes it can
deal with. Then I present some striking results in the light and heavy quarks
sectors. Finally I try to guess the prospects.


title:
Can light Goldstone boson loops counter the `S-argument' against
  Technicolor?

abstract:
  We examine the oblique correction phenomenology of one-family Technicolor
with light pseudo-Goldstone bosons. From loop calculations based on a gauged
chiral lagrangian for Technicolor, we are lead to conclude that even though
loops with light Goldstone bosons give a negative contribution to $S$ measured
at the $Z$-pole, this effect is not sufficiently large to unambiguously counter
the `S-argument' against one-family Technicolor. This result cannot be guessed
\apriori, but must be explicitly calculated. Our analysis entails an extended
version of the $STU$ oblique parametrization of Peskin and Takeuchi. In
principle, this extended formalism ($STUVWX$) must be used when there are light
new particles in loops.


title: Heavy quarkonium Systems and Nonperturbative Field Correlators

abstract:
  Bound states of heavy quarks are considered. Using the path integral
formalism we are able to rederive, in a gauge invariant way, the
Leutwyler-Voloshin short distance analysis as well as a long distance linear
potential. At all distances we describe the states in terms of nonperturbative
field correlators, and we include radiative corrections at short and
intermediate distances. For intermediate distance states (particularly $b\bar
{b}$ with $n=2$) our results improve, qualitatively and quantitatively,
standard analyses, thanks mostly to being able to take into account the
finiteness of the correlation time.


title: The 331 model with right-handed neutrinos

abstract:
  We explore some more consequences of the $SU(3)_L\otimes U(1)_N$ electroweak
model with right-handed neutrinos. By introducing the $Z - Z'$ mixing angle
$\phi$, the {\it exact} physical eigenstates for neutral gauge bosons are
obtained. Because of the mixing, there is a modification to the $Z^1$ coupling
proportional to $\sin\phi$. The data from the $Z$-decay allows us to fix the
limit for $\phi$ as $-0.0021 \leq \phi \leq 0.000132$. >From the neutrino
neutral current scatterings, we estimate a bound for the new neutral gauge
boson $Z^2$ mass in the range 300 GeV, and from symmetry-breaking hierarchy a
bound for the new charged and neutral (non-Hermitian) gauge bosons $Y^{\pm},
X^o$ are obtained.


title:
Search for the $\chi'_c$ Charmonium States as Solution to the CDF
  $\psi'$ Puzzle

abstract:
  The efforts of Roy-Sridhar-Close-Cho-Wise-Trivedi to resolve the CDF $\psi'$
anomaly with cascades from above-threshold $\chi^\prime_c$ states require well
defined signature states require well defined signatures [a small total width
and a large branching fraction for $\cp \ra \gamma + \pp]$ for the solution to
be viable. Here we estimte the production of such states from $BR (B \ra \cp +
X)BR (\cp \ra \gamma \pp)$ and $\gamma \gamma$ production of $\chi^\prime_{c2}$
at CLEO II, and comment on the feasbility of testing the hypothesis in terms of
current experimental capabilities.


title: $\Omega_c$ and other charmed baryons revisited

abstract:
  The mass of the $\Omega^0_c$ baryon with quark content (ssc) is computed in a
potential model whose parameters have been determined in 1981 by fitting the
spectrum of heavy mesons. It is found in perfect agreement with a recent
measurement at the CERN hyperon-beam experiment. The spectroscopy of other
charmed baryons in potential models is briefly reviewed.


title: Spin Contents of Nucleons with SU(3) Breaking

abstract:
  We apply a model for SU(3) breaking to the analysis of the spin contents of
the nucleon from the the latest data on first moments of the spin dependent
structure functions and include higher order QCD corrections. The results show
that the value of the total quark spin contribution to the nucleon spin $\Delta
\Sigma \equiv \Delta u + \Delta d +\Delta s$ remains about 0.3 and is very
insensitive to SU(3) breaking, while the result for the strange quark
contribution varies considerably with SU(3) breaking.


title: Abelian versus Non-Abelian Higgs Model in Three Dimensions

abstract:
  We study the phase structure of the abelian Higgs model in three dimensions
based on perturbation theory and a set of gauge independent gap equations for
Higgs boson and vector boson masses. Contrary to the non-abelian Higgs model,
the vector boson mass vanishes in the symmetric phase. In the Higgs phase the
gap equations yield masses consistent with perturbation theory. The phase
transition is first-order for small values of the scalar self-coupling
$\lambda$, where the employed loop expansion is applicable.


title:
Mass Bounds for the Neutral Higgs Bosons in the Next-To-Minimal
  Supersymmetric Standard Model

abstract:
  In the Next--To--Minimal Supersymmetric Standard Model (NMSSM), the Higgs and
neutralino/chargino sectors are strongly correlated by four common parameters
at tree level. Therefore we analyze the experimental data from both the search
for Higgs bosons as well as for neutralinos and charginos at LEP 100 in order
to constrain the parameter space and the masses of the neutral Higgs particles
in the NMSSM. We find that small singlet vacuum expectation values are ruled
out, but a massless neutral Higgs scalar and pseudoscalar is not excluded for
most of the parameter space of the NMSSM. Improved limits from the
neutralino/chargino search at LEP 200, however, may lead to nonvanishing lower
Higgs mass bounds.


title:
TOP-INDUCED ELECTROWEAK BREAKING IN THE MINIMAL SUPERSYMMETRIC STANDARD
  MODEL

abstract:
  Severe constraints on parameters of the minimal supersymmetric standard model
follow from a dynamical electroweak symmetry breaking mechanism dominated by
top and stop loops. In particular, the lightest Higgs boson mass is expected to
be smaller than 100 GeV.


title:
Hadron Helicity Violation in Exclusive Processes: Quantitative
  Calculations in Leading Order QCD

abstract:
  We study a new mechanism for hadronic helicity flip in high energy hard
exclusive reactions. The mechanism proceeds in the limit of perfect chiral
symmetry, namely without any need to flip a quark helicity. The fundamental
feature of the new mechanism is the breaking of rotational symmetry of the hard
collision by a scattering plane in processes involving independent quark
scattering. We show that in the impulse approximation there is no evidence for
of the helicity violating process as the energy or momentum transfer $Q^2$ is
increased over the region 1 GeV^2 < Q^2 < 100 GeV^2. In the asymptotic region
Q^2> 1000 GeV^2, a saddle point approximation with doubly logarithmic accuracy
yields suppression by a fraction of power of Q^2. ``Chirally--odd" exclusive
wave functions which carry non--zero orbital angular momentum and yet are
leading order in the high energy limit, play an important role.


title: Exclusive Scattering at ELFE

abstract:
  The theoretical framework of hard exclusive reactions is reviewed with
special emphasis on the Elfe project program. Perturbative QCD studies have
shown that factorization properties allow to separate well-defined non
perturbative objects which are crucial in the understanding of confinement
dynamics from perturbatively calculable hard processes. The applicability of
this factorization in a definite energy domain is controlled by some definite
statements, as the dimensional counting rules, the helicity conservation law
and the appearance of color transparency. The few data available indicate that
the Elfe parameters indeed correspond to this well defined physics.


title: WIMP Mass Determination with Neutrino Telescopes

abstract:
  Weakly-interacting massive particles (WIMPs) annihilating in the center of
the Sun or the Earth may give rise to energetic neutrinos which might be
discovered by astronomical neutrino detectors. The angular distribution of the
neutrino-induced muons is considered in detail via Monte Carlo simulations. It
is shown that large underground \v{C}erenkov neutrino telescopes might be able
to extract the WIMP mass from the width of the muon angular distribution.


title: Multiplicity distribution of colour dipoles at small~$x$

abstract:
  The colour dipole multiplicity distribution is analysed for the wave function
of a heavy onium state at small $x$. Numerical results for the average
multiplicity and the effect of cutoffs on its power growth are presented. Then,
the full multiplicity distribution is analysed: the second multiplicity moment
is derived and the tail of the distribution is shown to behave as $\exp(-\log^2
n)$. These results are confirmed by a Monte Carlo simulation which also gives
the fluctuations in the spatial density of dipoles.


title: Dynamical Parton Distributions for alpha_{S} Determinations

abstract:
  Precise determinations of the strong coupling constant in hadronic collisions
demand sets of parton densities spanning a sufficiently wide range of values
for the QCD scale parameter Lambda. For such applications, we supplement the
recent GRV parametrization by five sets of dynamically generated parton
distributions for Lambda-values corresponding to alpha_{S}(M_{Z}^{2}) between
0.104 and 0.122. Present DIS data, including recent small-x HERA results, do
not appreciably discriminate between these sets.


title: The final state hadrons in polarised deep inelastic scattering

abstract:
  General arguments suggest that the non-perturbative background field in QCD
may have a non-trivial spin structure. We discuss how this effect may be
manifest in semi-inclusive measurements of fast pions in polarised deep
inelastic scattering.


title: On the Atmospheric Neutrino Anomaly and its Statistical Significance

abstract:
  An analysis of the existing data on the atmospheric neutrino anomaly is
presented, focused on the statistical significance that can be attributed to
its experimental evidence. Our approach is alternative to the usual analyses in
terms of the $\mu/e$ ratio of event rates. In fact, we perform a comparison
between data and expectations, by {\em separating\/} the information on
$e$-like and $\mu$-like events, with a careful estimate of the different errors
and of their correlation effects. The results are shown both numerically and
graphically, and disclose interesting aspects of the atmospheric neutrino
anomaly, that the use of the $\mu/e$ ratio would partially hide, both in the
sub-GeV and in the multi-GeV energy range.


title: K_L to \pi^+ \pi^- e^+ e^-

abstract:
  We calculate all of the form factors for the one-photon, $K_L \rightarrow
\pi^+ \pi^- \gamma^* \rightarrow \pi^+ \pi^- e^+e^-$ contribution to the $K_L
\rightarrow \pi^+ \pi^- e^+e^-$ decay amplitude at leading order in chiral
perturbation theory. These form factors depend on one unknown constant that is
a linear combination of coefficients of local ${\cal O}(p^4)$ operators in the
chiral lagrangian for weak radiative kaon decay. We determine the differential
rate for $\K$ and also the magnitude of two CP violating observables.


title: CHIRAL SYMMETRY AND $U_A(1)$ ANOMALY IN AN EFFECTIVE THEORY OF QCD

abstract:
  We show on the basis of an effective theory of QCD that a wide variety of
observables in the hadron world is governed by the chiral symmetry together
with an interplay between the axial anomaly and the explicit symmetry breaking
due to the current quark mass. We also discuss the nature of the chiral
transition at finite temperature and related dynamical phenomena using the
effective Lagrangian. Some phenomenological implications of the small vector
coupling (``vector limit'') at high temperatures are suggested.


title:
Phenomenology of $x_F$ Dependence of Quarkonium Production in
  Proton-Nucleus Interactions

abstract:
  We present a phenomenological study of the $x_F$ dependence of quarkonium
production in high energy proton-nucleus collisions. The \xf~dependence of
comover contributions is introduced to account for the observed quarkonium
suppression at low $x_F$. Combining comover contributions, nuclear shadowing
effect, energy loss mechanism and nuclear absorption together we reproduce the
overall \xf~dependence of E772/E789 data.


title: Comment on a mechanism of dynamical breaking of supersymmetry

abstract:
  We re-examine the so-called Nambu-Jona-Lasinio mechanism suggested by Song,
Xu and Chin in breaking the supersymmetry in the Wess-Zumino model and show
that this mechanism cannot be justified without assuming special effects
between fermions. The fermion condensation suggested by them corresponds to an
unstable vacuum configuration. As a result, there is no fermion condensation
and no supersymmetry breaking in the model discussed by them.


title: Yukawa matrices from a spontaneously broken abelian symmetry

abstract:
  We classify all the phenomenologically viable fermion mass matrices coming
from a spontaneously broken abelian symmetry $ U(1)_X, $ with one and two
additional chiral fields of opposite charges $ X=\pm 1. $ We find that the
non-trivial K\"ahler metric can fill zeroes of the fermion mass matrices up to
phenomenologically interesting values. A general anomaly analysis shows that
for one additional chiral field the only way to achieve anomaly cancellation is
by use of the Green-Schwarz mechanism. For two additional fields with $X=\pm 1$
and negative charge differences in the lepton sector the anomalies can however
be directly put to zero. This case gives a unique prediction for the ratio of
the two Higgs scalars of MSSM, ${\rm tg} \beta \sim { m_t \over m_b} (sin
\theta_c)^ 2$, where $\theta_c$ is the Cabibbo angle.


title:
INITIAL-STATE COLOUR DIPOLE EMISSION ASSOCIATED WITH QCD POMERON
  EXCHANGE

abstract:
  The initial-state radiation of soft colour dipoles produced together with a
single QCD Pomeron exchange (BFKL) in onium-onium scattering is calculated in
the framework of Mueller's approach. The resulting dipole production grows with
increasing energy and reveals an unexpected feature of a power-law tail at
appreciably large transverse distances from the collision axis, this phenomenon
being related to the scale-invariant structure of dipole-dipole correlations.


title:
Nonlocality as an Explanation for Finetuning and Field replication in
  Nature

abstract:
  Constants of Nature that have nongeneric values pose a riddle often referred
to as the finetuning problem. The conspicuous values assumed by many physical
constants (e.g., the vanishing effective cosmological constant, the smallness
of the Higgs mass compared to the Planck scale, the finestructure constants,
$\Theta_{QCD}$) seem to coincide with values that are obtained if one assumes
that Nature in general seeks out multiple point values for intensive
parameters. Multiple point values would occur in the presence of many
coexisting phases. Such coexistence could be enforced by having fixed but not
finetuned amounts of extensive quantities. We show that universally fixed
amounts of extensive quantities is tantamount to having long range nonlocal
interactions of a special type: these interactions are identical between fields
at all pairs of spacetime points regardless of the spacetime distance between
them. Such omnipresent nonlocal interactions, which can be described by a very
general form of a reparameterization invariant action, would not be perceived
as ``action at a distance'' but rather most likely incorporated into our theory
as constants of Nature. Hence one can speculate that this mild form of
nonlocality is the underlying explanation of Nature's affinity for the multiple
point. We also speculate that nonlocal effects, described by fields depending
on two spacetime points, may be responsible for the replication of the fields
in three generations. Such a nonlocal mechanism would also triple the number of
boson fields, as in the antigrand unification model. We briefly review the
multiple point predictions for the three fine structure constants and the
resolution of the quark-lepton mass hierarchy problem in this antigrand unified
extension of the Standard Model.


title: Phenomenology of Light Gauginos

abstract:
  I advocate the virtues of a very economical version of the minimal
supersymmetric standard model which avoids cosmological problems often
encountered in dynamical SUSY-breaking and solves the SUSY-CP problem. Imposing
$m_Z=91$ GeV and $m_t \sim 175$ GeV implies that scalar masses are generally
$100-200$ GeV. The gluino and photino are massless at tree level. At 1-loop,
the gluino mass is predicted to be in the range $m_{\gluino}: 100 - 600$ MeV
and the photino mass can be estimated to be $m_{\photino}: 100 - 1400$ MeV. New
hadrons with mass $\sim 1 \frac{1}{2}$ GeV are predicted and described. The
``extra'' flavor singlet pseudoscalar observed in two experiments in the
$\iota(1440)$ region, if confirmed, is naturally interpreted as the state which
gets its mass via the QCD anomaly. Its superpartner, a gluon-gluino bound
state, generally has a lifetime longer than $5~10^{-11}$ sec and would not have
shown up in existing searches. Search strategies and other consequences of the
scenario are discussed.


title:
Disoriented and Plastic Soft Terms: A Dynamical Solution to the Problem
  of Supersymmetric Flavor Violations

abstract:
  We postulate that the orientation of the soft supersymmetry-breaking terms in
flavor space is not fixed by tree level physics at the Planck scale; it is a
dynamical variable which depends on fields that have no tree level potential.
These fields can be thought of as either moduli or as the Nambu-Goldstone
bosons of the spontaneously broken flavor symmetry which is non-linearly
realized by the soft terms. We show that the soft terms align with the quark
and lepton Yukawa couplings, just as spins align with an external magnetic
field. As a result, the soft terms conserve individual lepton numbers and do
not cause large flavor or CP violations. The vacuum adjusts so as to allow
large sparticle splittings to naturally coexist with flavor conservation.
Consequently, the resulting phenomenology is different from that of minimal
supersymmetric theories. We also propose theories in which the shape of the
soft terms in flavor space is a dynamical variable which depends on fields that
have no tree level potential. This dynamically leads to partial degeneracy
among sparticles and further supression of flavor violations. The ideas of this
paper suggest a connection between the space of moduli and the spontaneously
broken flavor group.


title: On particle--like jets

abstract:
  Under which conditions does a jet appear as a particle--like signal from the
hidden realm of quarks and gluons? Motivated by this question jet clustering
conditions are formulated, in order to characterize jet clustering algorithms,
which can be used for a determination of particle--like jets. Jets are
understood as particle--like, if they behave like free particles. The simplest
solution to the jet clustering conditions leads to a new jet algorithm: a
Lorentz invariant generalization of the JADE algorithm. It is found that this
generalization amplifies hadronization effects in certain phase space regions
in such a way, that hadronization models might become testable in jet physics
at the electron--proton collider HERA. Moreover, a method is suggested, which
can be used at HERA, in order to determine a region in the phase space, where
hadronization effects from the proton remnant are small and where parton jets
are particle--like.


title: LOW ENERGY NUCLEON-NUCLEON SCATTERING IN THE SKYRME MODEL

abstract:
  We present the study of the influence of the leading contribution from the
kinetic energy of the Skyrme Lagrangian on the scattering of low energy
nucleons. This classical kinetic energy for the 2-body system is computed using
the product ansatz and is correct for low energy, well separated Skyrmions. We
quantize the rotational degrees of freedom of the Skyrmions in order to give
them the right spin and isospin values. We are then able to compute
analytically the scattering angles for some angular momenta polarizations.


title:
Limits on Extensions of the Minimal Standard Model from Combined LEP
  Lineshape Data

abstract:
  The high statistics of the combined LEP lineshape data are used to derive
constraints on hypothetical extensions of the Minimal Standard Model. The data
comprises about eight million visible Z decays, recorded between 1989 and 1993.
This letter gives limits for simple tests on models which predict additional Z
boson decays or modified Z-couplings. As an application the two-doublet Higgs
model is considered.


title: Status of Higgs Hunting at LEP -- Five Years of Progress

abstract:
  New results from general searches for the Higgs boson of the Minimal Standard
Model (MSM), and for neutral and charged Higgs bosons of non-minimal Higgs
models are reviewed from the four LEP experiments at CERN: ALEPH, DELPHI, L3,
and OPAL. Much progress has been made due to the analysis of new data sets. A
total of about 13 million hadronic Z decays are recorded from 1989 to 1994. The
Higgs boson discovery potential for LEP2 is presented.


title:
"Fixed point" QCD Analysis of the CCFR Data on Deep Inelastic Neutrino-
  Nucleon Scattering

abstract:
  The results of LO \it {Fixed Point} QCD (FP - QCD) analysis of the CCFR data
for the nucleon structure function $~xF_3(x,Q^2)~$ are presented. The predic-
tions of FP - QCD, in which $~\alpha_s(Q^2)~$ tends to a nonzero coupling
constant $~\alpha_0~$ as $~Q^2\to \infty~$, are in good agreement with the
data. The description of the data is even better than that in the case of LO
QCD. The FP-QCD parameter $~\alpha_0~$ is determined with a good accuracy:
$~\alpha_0 = 0.198\pm 0.009~$. Having in mind the recent QCD fits to the same
data we conclude that unlike the high precision and large $~(x,Q^2)~$ kinematic
range of the CCFR data they cannot discriminate between QCD and FP - QCD
predictions for $~xF_3(x,Q^2)~$.


title:
Some Features of the Hadronic $B_c^{(*)}$-meson Production at Large
  $p_T$

abstract:
  Calculations of the hadronic $B^{(*)}_c$-mesons production performed in the
framework of the perturbative QCD taking into account $O(\alpha_s^4)$ Feynmann
diagrams are presented. A comparison of the exact calculations with those based
on the fragmentation model of $\bar b\rightarrow B^{(*)}_c+X$ shows the large
discrepancy between them. The exact calculations of the $B^{(*)}_c$-mesons
production cross-sections as the function of $p_T$ at the energy of the FNAL
Tevatron ($\sqrt{s}=1.8$ TeV) are given. The predicted ratio of the vector to
the pseudoscalar state cross-sections is about $R\sim 3$ instead of $R\sim 1.4$
for the fragmentation model.


title: Chaos Driven by Soft-Hard Mode Coupling in Thermal Yang-Mills Theory

abstract:
  We argue on a basis of a simple few mode model of SU(2) Yang-Mills theory
that the color off-diagonal coupling of the soft plasmon to hard thermal
excitations of the gauge field drives the collective plasma oscillations into
chaotic motion despite the presence of the plasmon mass.


title: U(2)_{L}\times U(2)_{R} Chiral Theory of Mesons

abstract:
  A $U(2)_{L}\times U(2)_{R}$ chiral theory of pseudoscalar, vector, and
axial-vector mesons has been proposed. VMD has been revealed from this theory.
The physical processes of normal parity and abnormal parity have been studied
by using the same lagrangian and the universality of coupling has been
revealed. Two new mass relations between vector and axial-vector mesons have
been found. Weinberg's first sum rule and new relations about the amplitude of
$a_{1}$ decay are satisfied. KSFR sum rule is satisfied pretty well. The $\rho$
pole in pion form factor has been achieved. The theoretical results of
$\rho\rightarrow\pi\pi$, $\omega\rightarrow \pi\pi$, $a_{1}\rightarrow\rho\pi$
and $\pi\gamma$, $\tau\rightarrow \rho\nu$, $\tau\rightarrow a_{1}\nu$,
$\pi^{0}\rightarrow \gamma\gamma$, $\omega \rightarrow\pi\gamma$,
$\rho\rightarrow\pi\gamma$, $f_{1} \rightarrow\rho\pi\pi$,
$f_{1}\rightarrow\eta\pi\pi$, $\rho\rightarrow\eta\gamma$, $\omega
\rightarrow\eta\gamma$ are in good agreement with data. Weinberg's $\pi\pi$
scattering lengths and slopes and $a^{0}_{2}$, $a^{2}_{2}$, and $b^{1}_{1}$
have been obtained. Especially, the $\rho$ resonance in the amplitude
$T^{1}_{1}$ of $\pi\pi$ scattering has been revealed from this theory. Two
coefficients of chiral perturbation theory have been determined and they are
close to the values used by chiral perturbation theory.


title: Revisit of Weinberg's sum rules

abstract:
  By applying the Ward identity found by Weinberg two new relations of the
amplitude of $a_{1}\rightarrow\rho\pi$ with other physical quantities have been
found.


title: The Role of CP violation in D0 anti-D0 Mixing

abstract:
  In current searches for D0 anti-D0 mixing, the time evolution of
``wrong-sign'' decays is used to distinguish between a potential mixing signal
and the dominant background from doubly-Cabibbo-suppressed decays. A term
proportional to $\Delta Mt$ in the expression for the time evolution is often
neglected in theoretical discussions and experimental analyses of these
processes. We emphasize that, in general, this term does not vanish even in the
case of CP invariance. Furthermore, CP invariance is likely to be violated if
the rate of D0 anti-D0 mixing is close to the experimental bound. The
consequence of either of these two facts is that the strongest existing
measured bound is not applicable for constraining New Physics.


title: Preserving Flat Directions During Inflation

abstract:
  Supersymmetry is generally broken by the non-vanishing vacuum energy density
present during inflation. In supergravity models, such a source of
supersymmetry breaking typically makes a contribution to scalar masses of order
${\tilde m}^2 \sim H^2$, where $H^2 \sim V/M_P^2$ is the Hubble parameter
during inflation. We show that in supergravity models which possess a
Heisenberg symmetry, supersymmetry breaking makes no contribution to scalar
masses, leaving supersymmetric flat directions flat at tree-level. One-loop
corrections in general lift the flat directions, but naturally give small
negative squared masses $\sim - g^2 H^2/(4\pi)^2$ for all flat directions that
do not involve the stop. No-scale supergravity of the SU(N,1) type and the
untwisted sectors from orbifold compactifications are special cases of this
general set of models. We point out the importance of the preservation of flat
directions for baryogenesis.


title: Unstable Particles

abstract:
  Unstable particles cannot be treated as asymptotic external states in
$S$-matrix theory and when they occur as resonant states cannot be described by
finite-order perturbation theory. The known facts concerning unstable particles
are reviewed and it is shown how to construct gauge-invariant expressions for
matrix elements containing intermediate unstable particles and physically
meaningful production cross-sections for unstable particles. The results and
methodology presented are relevant for $Z^0$ resonance physics, $W^+W^-$ and
$Z^0Z^0$ pair production and can be straightforwardly applied to other
processes.


title:
Polarization Effects in Chargino Production at High Energy
  $\gamma\gamma$ Colliders

abstract:
  We investigate the chargino production process
$\gamma\gamma\rightarrow\tilde{W}^{+}\tilde{W}^{-}$ at high energy
$\gamma\gamma$ colliders in the framework of the minimal supersymmetric
standard model (MSSM). Here the high energy $\gamma$ beams are obtained by the
backward Compton scattering of the laser flush by the electron in the basic
linear TeV $ee$ colliders. We consider the polarization of the laser photons as
well as the electron beams. Appropriate beam polarization could be effective to
enhance the cross section and for us to extract the signal from the dominant
background $\gamma\gamma\rightarrow{W}^{+}{W}^{-}$.


title:
The Chiral Phase Transition in QCD: Critical Phenomena and Long
  Wavelength Pion Oscillations

abstract:
  In QCD with two massless quarks, the chiral phase transition is plausibly in
the same universality class as the classical O(4) magnet. To test this
hypothesis, critical exponents characterizing the behaviour of universal
quantities near the 2nd order critical point can be calculated and compared to
results from lattice simulations. Present simulations already allow many
qualitative tests; quantitative tests await future simulations with longer
correlation lengths. In a heavy ion collision, a long correlation length would
lead to large fluctuations in the number ratio of neutral to charged pions.
Unfortunately, no equilibrium correlation length gets long enough for this to
occur. Modelling the dynamics of the chiral order parameter in a far from
equilibrium transition by quenching in the linear sigma model suggests that
long wavelength modes of the pion field can be amplified. This could have
dramatic phenomenological consequences. Theoretical advances include attempts
to relax the quench approximation and to include expansion and quantum effects.
Long wavelength pion oscillations arise in a number of theoretical treatments;
however, all involve idealizations and are at best qualitative guides. It is up
to experimentalists to determine whether such phenomena occur; detection in a
heavy ion collision would imply an out of equilibrium chiral transition.


title: $\mu^+e^- <---> \mu^- e^+$ Transitions via Neutral Scalar Bosons

abstract:
  With $\mu\to e\gamma$ decay forbidden by multiplicative lepton number
conservation, we study muonium--antimuonium transitions induced by neutral
scalar bosons. Pseudoscalars do not induce conversion for triplet muonium,
while for singlet muonium, pseudoscalar and scalar contributions add
constructively. This is in contrast to the usual case of doubly charged scalar
exchange, where the conversion rate is the same for both singlet and triplet
muonium. Complementary to muonium conversion studies, high energy $\mu^+e^- \to
\mu^- e^+$ and $e^-e^- \to \mu^- \mu^-$ collisions could reveal spectacular
resonance peaks for the cases of neutral and doubly charged scalars,
respectively.


title: Gauge Unification, Yukawa Hierarchy and the $\mu$ Problem

abstract:
  The hierarchy in the Yukawa couplings may be the result of a gauged
horizontal $U(1)_H$ symmetry. If the mixed anomalies of the Standard Model
gauge group with $U(1)_H$ are cancelled by a Green-Schwarz mechanism, a
relation between the gauge couplings, the Yukawa couplings and the $\mu$-term
arises. Assuming that at a high energy scale $g_3^2=g_2^2={5\over3}g_1^2$ and
$(m_e m_\mu m_\tau)/(m_d m_s m_b)\sim \lambda$ (where $\lambda$ is of the order
of the Cabibbo angle), the $U(1)_H$ symmetry solves the $\mu$-problem with
$\mu\sim\lambda m_{3/2}$.


title: Scaling Relations in Phenomenology of QCD Sum Rules for Heavy Quarkonium

abstract:
  In the framework of a specific scheme of the QCD sum rules for $S$-wave
levels of the heavy quarkonium, one derives expressions, relating the leptonic
constants, the energetic density of quarkonium states and universal
characteristics in the heavy quarkonium physics, such as the difference between
the masses of heavy quark $Q$ and meson $(Q\bar q)$ and the number of heavy
quarkonium levels below the threshold of $(Q\bar Q) \to (Q\bar q) + (\bar Q q)$
decay.


title:
New LEP bounds on $B$-violating scalar couplings: R-parity violating
  supersymmetry or diquarks

abstract:
  We use the precision electroweak data at LEP to place bounds on $B$-violating
Yukawa couplings, two theoretically appealing examples being provided by
$R$-parity--violating supersymmetry and diquarks. The couplings involving the
third generation quarks are most severely constrained. These bounds are
complementary to those obtained from low-energy processes.


title: Spurious Anomalies in Dimensional Renormalization

abstract:
  A set of procedures is given for avoiding the spurious anomalies that are
generated when the 't Hooft - Veltman definition of gamma5 is used in
conjunction with renormalization by minimal subtraction. These procedures are
derived from the standard procedure, which requires in addition various finite
renormalizations to remove spurious violations of chiral symmetry. They apply
to open fermion lines, including flavor changing currents, to closed fermion
loops, including those which contain true anomalous currents, and to anomalous
loops connected to open fermion lines, to all orders in QCD.


title:
ANALYTICAL EXPRESSIONS FOR RADIATIVELY CORRECTED HIGGS MASSES AND
  COUPLINGS IN THE MSSM

abstract:
  We propose, for the computation of the Higgs mass spectrum and couplings, a
renormalization-group improved leading-log approximation, where the
renormalization scale is fixed to the top-quark pole mass. For the case
$m_A\sim M_{\rm SUSY}$, our leading-log approximation differs by less than 2
GeV from previous results on the Higgs mass computed using a nearly scale
independent renormalization-group improved effective potential up to
next-to-leading order. Moreover, for the general case $m_A\simlt M_{\rm SUSY}$,
we provide analytical formulae (including two-loop leading-log corrections) for
all the masses and couplings in the Higgs sector. For $M_{\rm SUSY}\simlt 1.5$
TeV and arbitrary values of $m_A$, $\tan\beta$ and the stop mixing parameters,
they reproduce the numerical renormalization-group improved leading-log result
for the Higgs masses with an error of less than 3 GeV. For the Higgs couplings,
our analytical formulae reproduce the numerical results equally well.
Comparison with other methods is also performed.


title: The difficulties involved in calculating $\delta\rho$

abstract:
  We discuss the difficulties that arise when one tries to calculate
$\delta\rho$ using dispersion relations.


title:
A proposal to search for a monochromatic component of solar axions using
  $^{57}$Fe

abstract:
  A new experimental scheme is proposed to search for almost monochromatic
solar axions, whose existence has not been discussed heretofore. The axions
would be produced when thermally excited $^{57}$Fe in the sun relaxes to its
ground state and could be detected via resonant excitation of the same nuclide
in a laboratory. A detailed calculation shows that the rate of the excitation
is up to order 10 events/day/kg-$^{57}$Fe. The excitation can be detected
efficiently using bolometers or liquid scintillators.


title: Physics of B_c mesons

abstract:
  In the framework of potential models for heavy quarkonium the mass spectrum
for the system ($\bar b c$) is considered. Spin-dependent splittings, taking
into account a change of a constant for effective coulomb interaction between
the quarks, and widths of radiative transitions between the ($\bar b c$) levels
are calculated. In the framework of QCD sum rules, masses of the lightest
vector $B_c^*$ and pseudoscalar $B_c$ states are estimated, scaling relation
for leptonic constants of heavy quarkonia is derived, and the leptonic constant
$f_{B_c}$ is evaluated. The $B_c$ decays are considered in the framework of
both the potential models and the QCD sum rules, where the significance of
Coulomb-like corrections is shown. The relations, following from the
approximate spin symmetry for the heavy quarks in the heavy quarkonium, are
analysed for the form factors of the semileptonic weak exclusive decays of
$B_c$. The $B_c$ lifetime is evaluated with the account of the corrections to
the spectator mechanism of the decay, because of the quark binding into the
meson. The total and differential cross sections of the $B_c$ production in
different interactions are calculated. The analytic expressions for the
fragmentational production cross sections of $B_c$ are derived. The possibility
of the practical $B_c$ search in the current and future experiments at
electron-positron and hadron colliders is analysed.


title: SEARCHING FOR COLD DARK MATTER

abstract:
  The differential cross-section for the elastic scattering of the lightest
supersymmetric particle (LSP) with nuclear targets is calculated in the context
of currently fashionable supersymmetric theories (SUSY). An effective four
fermion interaction is constructed by considering i) $Z^0$ exchange ii)s-quark
exchange and iii) Higgs exchange. It is expressed in terms of the form factors
$f^0_V,f^0_A, f^0_S$ (isoscalar) and $f^1_V,f^1_A$ and $f^1_S$ (isovector)
which contain all the information of the underlining theory. Numerical values
were obtained using representative input parameters in the constrained
parameter space of SUSY phenomenology. Both the coherent and for odd-A nuclei
the incoherent (spin) nuclear matrix elements were evaluated for nuclei of
experimental interest. The spin matrix elements tend to dominate for
  odd nuclei but the coherent matrix elements become more important in all
other cases. For the coherent part the Higgs contribution competes with the Z-
and s-quark contributions. Cross-sections as high as $10^{-37} cm^2$ have been
obtained.


title: Higgs Physics and the Equivalence Theorem

abstract:
  The equivalence theorem is an extremely useful tool to calculate heavy Higgs
{\it and} top-quark effects for processes that have center-of-mass-energies
(much) larger than the $W$ boson mass. After an explanation of the
renormalization procedures involved, the results for one- and two-loop
radiative corrections to the fermionic Higgs decay, $H\rightarrow f\bar f$, are
given and discussed. Finally, the renormalization scheme dependence is
examined, and the reliability of the perturbative series is investigated.


title: Response of Mica to Weakly Interacting Massive Particles

abstract:
  We calculate spin-dependent cross sections for the scattering from mica of
hypothetical weakly interacting dark-matter particles such as neutralinos. The
most abundant odd-A isotopes in mica, Al27 and K39, require different
shell-model treatments. The calculated cross sections will allow the
interpretation of ongoing experiments that look for tracks due to the
interaction of dark-matter particles with nuclei in ancient mica.


title: The Fermion Mass Problem

abstract:
  Different approaches to the quark-lepton mass problem are reviewed. The
infrared quasifixed point predictions for the top quark mass are discussed for
the Standard Model and its minimal supersymmetric extension, with particular
reference to the large $\tan\beta$ scenario and Yukawa unification. Mass matrix
ans\"{a}tze with texture zeros at the unification scale are also considered. It
is argued that the hierarchy of fermion masses and mixing angles requires the
existence of an approximately conserved chiral flavour symmetry beyond the
Standard Model.


title: Implications of SUSY Model Building

abstract:
  We discuss the motivations and implications of models of low-energy
supersymmetry. We present the case for the minimal supersymmetric standard
model, which we define to include the minimal particle content and soft
supersymmetry-breaking interactions which are universal at the GUT or Planck
scale. This model is in agreement with all present experimental results, and
yet depends on only a few unknown parameters and therefore maintains
considerable predictive power. From the theoretical side, it arises naturally
in the context of supergravity models. We discuss radiative electroweak
symmetry breaking and the superpartner spectrum in this scenario, with some
added emphasis on regions of parameter space leading to unusual or interesting
experimental signals at future colliders. We then examine how these results may
be affected by various modifications and extensions of the minimal model,
including GUT effects, extended gauge, Higgs, and matter sectors, non-universal
supersymmetry breaking, non-conservation of R-parity, and dynamical
supersymmetry breaking at low energies.


title: Quark Gluon Plasma from Numerical Simulations of Lattice QCD

abstract:
  Numerical simulations of quantum chromodynamics at nonzero temperature
provide information from first principles about the physical properties of the
quark gluon plasma. Because the lattice approximation can be refined
indefinitely, results of lattice simulations now provide the most reliable
basis for our understanding of the nonperturbative characteristics of the
plasma and of the high temperature phase transition. Following a brief overview
of the methodology of lattice gauge theory at nonzero temperature, recent
results and insights from lattice simulations are discussed. These include our
understanding of the phase diagram of QCD, the nature of the phase transition,
and the structure of the plasma.


title: Broken SU(3) Symmetry in Two-Body B Decays

abstract:
  The decays of $B$ mesons to two-body hadronic final states are analyzed
within the context of broken flavor SU(3) symmetry, extending a previous
analysis involving pairs of light pseudoscalars to decays involving one or two
charmed quarks in the final state. A systematic program is described for
learning information {}from decay rates regarding (i) SU(3)-violating
contributions, (ii) the magnitude of exchange and annihilation diagrams
(effects involving the spectator quark), and (iii) strong final-state
interactions. The implication of SU(3)-breaking effects for the extraction of
weak phases is also examined. The present status of data on these questions is
reviewed and suggestions for further experimental study are made.


title: ELECTROWEAK PENGUINS AND TWO-BODY B DECAYS

abstract:
  We discuss the role of electroweak penguins in $B$ decays to two light
pseudoscalar mesons. We confirm that the extraction of the weak phase $\alpha$
through the isospin analysis involving $B\to\pi\pi$ decays is largely
unaffected by such operators. However, the methods proposed to obtain weak and
strong phases by relating $B\to\pi\pi$, $B\to\pi K$ and $B\to KK$ decays
through flavor SU(3) will be invalidated if electroweak penguins are large. We
show that, although the introduction of electroweak penguin contributions
introduces no new amplitudes of flavor SU(3), there are a number of ways to
experimentally measure the size of such effects. Finally, using SU(3) amplitude
relations we present a new way of measuring the weak angle $\gamma$ which holds
even in the presence of electroweak penguins.


title: The Large-N_c Renormalization Group

abstract:
  In this talk we review how effective theories of mesons and baryons become
exactly soluble in the large-N_c limit. We start with a generic hadron
Lagrangian constrained only by certain well-known large-N_c selection rules.
The bare vertices of the theory are dressed by an infinite class of UV
divergent Feynman diagrams at leading order in 1/N_c. We show how all these
leading-order diagrams can be summed exactly using semiclassical techniques.
The saddle-point field configuration is reminiscent of the chiral bag: hedgehog
pions outside a sphere of radius \Lambda^{-1} (\Lambda being the UV cutoff of
the effective theory) matched onto nucleon degrees of freedom for r <
\Lambda^{-1}. The effect of this pion cloud is to renormalize the bare nucleon
mass, nucleon-\Delta hyperfine mass splitting, and Yukawa couplings of the
theory. The corresponding large-N_c renormalization group equations for these
parameters are presented, and solved explicitly in a series of simple models.
We explain under what conditions the Skyrmion emerges as a UV fixed-point of
the RG flow as \Lambda --> \infty.


title: The Rotationally Improved Skyrmion, or ``RISKY''

abstract:
  The perceived inability of the Skyrme model to reproduce pseudovector
pion-baryon coupling has come to be known as the ``Yukawa problem.'' In this
talk, we review the complete solution to this problem. The solution involves a
new configuration known as the rotationally improved Skyrmion, or ``RISKY,'' in
which the hedgehog structure is modified by a small quadrupole distortion. We
illustrate our ideas both in the Skyrme model and in a simpler model with a
global U(1) symmetry.


title: $s$-Channel Higgs Boson Production at a Muon-Muon Collider

abstract:
  High luminosity muon-muon colliders would provide a powerful new probe of
Higgs boson physics through $s$-channel resonance production. We discuss the
prospects for detection of Higgs bosons and precision measurements of their
masses and widths at such a machine.


title: Pion and neutron production by cosmic-ray muons underground

abstract:
  The production of positive pions and neutrons by cosmic muons at underground
sites of various depths is investigated. We first test the equivalent photon
method in the particular case of $\Delta$ excitation by the muon. We find that
this method, when it neglects the momentum dependence of the transverse
response, reproduces remarkably well the theoretical muon cross-section. This
success has lead us to apply the method to higher energies, where it has not
been tested. We evaluate in this way the production of positive pions in liquid
scintillator from known photo-absorption cross-sections. At a shallow depth of
20 meters our estimate reproduces the measurement. As for the neutron emission,
we include the obvious sources, such as the giant-resonance excitation, the
quasi-deuteron process, the quasi- free pion production as well as neutrons
emitted following pion capture. Our evaluation underestimates the number of
neutrons produced and finds a too weak dependence on the depth. This suggests
that secondary neutron production is important at all depths.


title: Extended technicolor contribution to the Zbb vertex

abstract:
  We show that the flavor-diagonal gauge boson of the extended technicolor
theory contributes with opposite sign to the standard model correction for the
$Zbb$ vertex. This mechanism can naturally explain the deviation of the LEP
result from the standard model prediction for the partial width $\Gamma(Z
\rightarrow b{\bar b})$. A smaller value of the QCD coupling, $\alpha_s(m_Z)
\simeq 0.115$, is then preferred by the $\Gamma(Z \rightarrow \mbox{hadron})$
data, which is consistent with both the recent Lattice-QCD estimate and the
Particle Data Group average.


title:
Model-independent determination of $\overline{m}_s$ from $\tau$-like
  inclusive decays in $e^+e^-$ and implications for the $\chi SB$-parameters

abstract:
  We determine the strange quark running mass of the $\overline{MS}$-scheme by
$simulating$ $\tau$-$like$ inclusive processes for the $old$ Das-Mathur-Okubo
sum rule relating the $e^+e^-$ into $I=0$ and $I=1$ hadrons total
cross-sections data. We obtain to three-loop accuracy: $\overline{m}_s$(1
GeV)=($196.7\pm 29.1$) MeV. By combining this result with the pseudoscalar sum
rule estimate of $(\overline{m}_d +\overline{m}_u)$ and the standard current
algebra values of the light quark mass ratios, we deduce the $average$:
$\overline{m}_d$(1 GeV)=$(10.3\pm 1.5)$ MeV, $\overline{m}_u$(1 GeV)=$(5.0\pm
1.5)$ MeV and $\frac{1}{2}\la \bar uu +\bar dd \ra$ (1 GeV) $ \simeq
-[(228.6\pm 9.1) \mbox{MeV}]^3$. Using also our value of $m_s$, we update the
estimates of the $K'(1.46)$ and $K^*_0(1.43)$ decay constants and of the
(pseudo)scalar two-point correlator subtraction constants. Then, we deduce a
deviation of about 34\% from kaon PCAC and the ratio of the {\it
normal-ordered} condensates: $\la \bar ss \ra /\la \bar uu \ra =
0.68^{+0.15}_{-0.29}$, which confirm previous findings from QCD spectral sum
rules. Finally, using the recent value of the $\overline{m}_b$ from the
$\Upsilon$-sum rules, we deduce the scale independent quark-mass ratio:
$m_b/m_s=34\pm 4$.


title:
QCD tests from $e^+e^- \rar I=1~$ hadrons data and implication on the
  value of $\alpha_s$ from $\tau$-decays

abstract:
  We re-examine the estimate of $\als$ and of the QCD condensates from
$e^+e^-\rar I=1$ hadrons data. We conclude that $e^+e^-$ at low energies gives
a value of $\Lambda$ compatible with the one from LEP and from tau inclusive
decay. Using a $\tau$-like inclusive process and QCD spectral sum rules, we
estimate the size of the $D$=4 to 9 condensates by a fitting procedure {\it
without invoking stability criteria}. We find $\la \als G^2 \ra =(7.1\pm
0.7)10^{-2}$ GeV$^4$, $\rho\als\la \bar uu\ra^2= (5.8\pm 0.9)10^{-4}$ GeV$^6$,
which confirm previous sum rules estimate based on stability criteria. The
corrections due to the $D=8$ condensates and to instantons on the vector
component of $\tau$-decay are respectively $\delta^{(8)}_1= -(1.5\pm
0.6)10^{-2}(1.78/M_\tau)^8$ and $\delta^{(9)}_1=-(7.0\pm
26.5)10^{-4}(1.78/M_\tau)^9 $, which indicate that the $\delta^{(8)}_1$ is one
order magnitude higher than the vacuum saturation value, while the $D\geq 9$
instanton-like contribution to the the vector component of the $\tau$-decay
width is a negligible correction. We also show that, due to the correlation
between the $D=4$ and $1/M^2_\tau$ contributions in the ratio of the Laplace
sum rules, the present value of the gluon condensate already excludes the
recent estimate of the $1/M^2_\tau$-term from FESR in the axial-vector channel.
Combining our non-perturbative results with the resummed perturbative
corrections to the $\tau$-width $R_\tau$, we deduce from the present data
$\alpha_s(M_\tau)= 0.33\pm 0.03$.


title:
Supersymmetric Box Contributions to $ e^+ e^- \to Z^0 h^0 $ and $ e^+
  e^- \to A^0 h^0 $

abstract:
  Within the MSSM we calculate the electroweak 1-loop box contributions to the
processes $ e^+ e^- \rightarrow Z^0 h^0 $ and $ e^+ e^- \rightarrow A^0 h^0 $.
We present detailed results for c. m. energies $\sqrt{s}=200$ GeV and
$\sqrt{s}=500$ GeV as well as for $\tan\beta=2$ and $\tan\beta=50$. The box
contributions to the process $ e^+ e^- \rightarrow Z^0 h^0 $ are, depending on
$\sqrt{s}$ and $\tan\beta$, of the order -2 to -20\% and to $ e^+ e^-
\rightarrow A^0 h^0 $ of 2 to 10\%.


title: Analytic Approach to Small-X Structure Functions

abstract:
  We present a method for the analytic solution of small $x$ structure
functions. The essential small $x$ logarithms are summed to all orders in the
anomalous dimensions and coefficient functions. Although we work at leading
logarithmic accuracy, the method is general enough to allow the systematic
inclusion of sub-leading logarithms. Results and predictions are presented for
the gluon density, and the structure functions $F_2(x,Q^2)$ and $F_L(x,Q^2)$.
We find that corrections to the simple double logarithmic calculation are
important in the HERA range and obtain good fits to all available data.


title: Anomaly-Free Gauged R-Symmetry in Local Supersymmetry

abstract:
  We discuss local \R-symmetry as a potentially powerful new model building
tool. We first review and clarify that a $U(1)$ \R-symmetry can only be gauged
in local and not in global supersymmetry. We determine the anomaly-cancellation
conditions for the gauged \R-symmetry. For the standard superpotential these
equations have {\it no} solution, independently of how many Standard Model
singlets are added to the model. There is also no solution when we increase the
number of families and the number of pairs of Higgs doublets. When the
Green-Schwarz mechanism is employed to cancel the anomalies, solutions only
exist for a large number of singlets. We find many anomaly-free
family-independent models with an extra $SU(3)_c$ octet chiral superfield. We
consider in detail the conditions for an anomaly-free {\it family dependent} $
U(1)_R$ and find solutions with one, two, three and four extra singlets. Only
with three and four extra singlets do we naturally obtain sfermion masses of
order the weak-scale. For these solutions we consider the spontaneous breaking
of supersymmetry and the $R$-symmetry in the context of local supersymmetry. In
general the $U(1)_R$ gauge group is broken at or close to the Planck scale. We
consider the effects of the \R-symmetry on baryon- and lepton-number violation
in supersymmetry. There is no logical connection between a conserved
\R-symmetry and conserved \R-parity. For conserved \R-symmetry we have models
for all possibilities of conserved or broken \R-parity. Most models predict
dominant effects which could be observed at HERA.


title: Non-perturbative Quarkonium Dissociation in Hadronic Matter

abstract:
  We calculate the dissociation rates of quarkonium ground states by tunnelling
and direct thermal activation to the continuum. For hadronic matter at
temperatures $T \leq 0.2$ GeV, neither of these mechanisms leads to a
sufficiently large dissociation to explain the experimentally observed
suppression of charmonium. Dissociation by sequential excitation to excited
energy levels, although OZI-forbidden, requires further analysis.


title: QCD CORRECTIONS TO HIGGS BOSON DECAYS

abstract:
  The two--loop ${\cal O}(\alpha_s G_F m_t^2)$ corrections to the $b\bar b$
decay rate of the Standard Model Higgs boson as well as its production via
$e^+e^- \to ZH$ will be presented. These QCD corrections are obtained by using
a low-energy theorem for light Higgs bosons compared to the top quark mass. The
results yield strong screening effects of the ${\cal O}(G_F m_t^2)$
contributions. After that the two-loop QCD corrections to the $\gamma\gamma$
and gluonic decays of the Higgs bosons of the Standard Model and its minimal
supersymmetric extension are discussed. While the corrections to the
$\gamma\gamma$ decays remain small of ${\cal O}(\alpha_s)$ they are huge $\sim$
50 -- 70 \% in the case of the gluonic decays.


title: Trilinear Gauge Boson Vertices in the MSSM

abstract:
  We study the $C$ and $P$ even $WW\gamma$ and $WWZ$ trilinear gauge boson
vertices (TGV's), in the context of the MSSM as functions of the soft SUSY
breaking parameters $A_0, m_0, M_{1/2}$ and the momentum $q$ carried by
$\gamma, Z$, assuming the external $W$'s are on their mass shell. We follow a
complete renormalization group analysis taking into account all constraints
imposed by the radiative breaking of the electroweak symmetry. It is found that
for energies ${\sqrt{s}} \equiv q^2 \le 200 \; GeV$ squark and slepton
contributions to the aforementioned couplings are two orders of magnitude
smaller than those of the Standard Model (SM). In the same energy range the
bulk of the supersymmetric Higgs corrections to the TGV's is due to the
lightest neutral Higgs, $h_0$, whose contribution is like that of a Standard
Model Higgs of the same mass. The rest have negligible effect due to their
heaviness. The contributions of the Neutralinos and Charginos are sensitive to
the input value for the soft gaugino mass $M_{1/2}$ being more pronounced for
values $M_{1/2} < 100 \; GeV$. In this case and in the unphysical region, $0 <
\sqrt{s} < 2 M_W $ their contributions are substantially enhanced resulting to
large corrections to the static quantities of the $W$ boson. However such an
enhancement is not observed in the physical region and their corrections to the
TGV's are rather small. In general for $2 M_W < \sqrt{s} < 200 \; GeV $ the
MSSM predictions differ from those of the SM but they are of the same order of
magnitude. Deviations from the SM predictions to be detectable require
sensitivities reaching the per mille level and hence unlikely to be observed at
LEP200. For higher energies SM and MSSM predictions exhibit a fast fall off
behaviour, in accord with unitarity requirements, getting smaller by almost an


title:
Solution of the high twist evolution equation in the double logarithmic
  approximation in QCD

abstract:
  The evolution equation for high twist operators is solved in the Double
Logarithmic Approximation for cylinder-type diagrams which dominate in the
limit of large number of colors. The asymptotic behaviour of the parton
correlation function is shown to be determined by the spectrum of the Ising
model for a one-dimensional chain of spin-1/2 magnets.


title: Model of Four Light Neutrinos in the Light of All Present Data

abstract:
  Motivated by existing and recent data on possible neutrino oscillations, we
propose a model of four light neutrinos ($\nu_e, \nu_\mu, \nu_\tau$, and a
singlet $\nu_S$) with a pattern of masses and mixing derivable from a $Z_5$
discrete symmetry and the seesaw mechanism. Atmospheric neutrino oscillations
occur between $\nu_\mu$ and $\nu_\tau$ as pseudo-Dirac partners; whereas solar
neutrino oscillations occur between $\nu_e$ and $\nu_S$, a linear combination
of which is massless. Additional oscillations may occur between $\nu_e$ and
$\nu_\mu$ to account for the recent observation of the LSND (Liquid
Scintillator Neutrino Detector) experiment.


title: COMMENT ON THE KAMIOKANDE ATMOSPHERIC NEUTRINO DEFICIT

abstract:
  I describe an attempt to understand the significance of the atmospheric
neutrino deficit observed by the Kamiokande neutrino detector. In particular, I
am concerned with the statistical significance quoted for the zenith-angle
dependence of the deficit, which has been cited as evidence for neutrino flavor
oscillations free of systematic uncertainties.


title: A Nonperturbative Study of Quarkonium Systems

abstract:
  Using Nonrelativistic QCD on the lattice we studied the mass spectrum of
quarkonium systems nonperturbatively for a range of the bar quark mass. We
determined two products of the matrix elements involved in quarkonium decays
and studied the mass dependence of the results. We predict from our
calculations the leptonic decay width of $\Upsilon$, and use the mass
dependence to predict the leptonic decay width of $J/\psi$. These calculations
agree with the experimental results. In lattice NRQCD an additional parameter
$n$ is introduced, and we study the sensitivity of our results to the choice of
$n$.


title: Testing CP Properties of Higgs Bosons

abstract:
  Possibilites for measuring the $J^{PC}$ quantum numbers of the Higgs particle
through its interactions with gauge bosons and with fermions are discussed.
Observables which indicate CP violation in these couplings are also identified.


title:
One-loop correction to the $\gamma W W$ vertex in the $e^- \gamma$
  collider

abstract:
  We apply the pinch technique , which is a method to construct the gauge
independent off-shell Green's functions, to the process $e^-\gamma \rightarrow
W^-\nu$ to study the effects of radiative corrections to $WW\gamma$ three gauge
boson vertex. The one-loop contributions to the anomalous gauge boson couplings
are estimated in the standard model.


title:
LOOKING AT THE QCD CORRECTIONS FOR LARGE $M_t$: AN EFFECTIVE LAGRANGIAN
  POINT OF VIEW

abstract:
  We discuss the QCD corrections to the large-$m_t$ electroweak contributions
to $\Delta r$ and to the process $Z\to b \bar b$ as two of the most
representative examples. This needs the construction of an effetive field
theory below the top quark. We discuss the issue of what $\mu$ scale is the
appropriate one at every stage and argue that, while matching corrections do
verify the simple prescription of taking $\mu \simeq m_t$ in $\alpha_s(\mu)$,
logarithmic (i.e. $\sim \log m_t$) corrections do not, and require the use of
the running $\alpha_s(\mu)$ in the corresponding renormalization group
equations. In particular we obtain the $\alpha_s$ correction to the
non-universal $\log m_t$ contribution to the $Zb\bar b$ vertex.


title:
ON MEASURING THE $\gamma \gamma$ WIDTH OF THE INTERMEDIATE- MASS HIGGS
  AT A PHOTON LINEAR COLLIDER

abstract:
  The identification of the intermediate-mass Higgs process $\gamma \gamma
\rightarrow H \rightarrow b\overline{b}$ will be one of the most important
goals of a future photon linear collider. Backgrounds from the continuum
$\gamma \gamma \rightarrow c\overline{c}, b\overline{b}$ leading-order
processes can be suppressed by using polarized photon beams in the $J_z = 0$
initial-state. The radiative processes $\gamma \gamma \rightarrow c\overline{c}
g, b\overline{b} g$ can mimic the two-jet topology of the Higgs signal and
provide the dominant background in the $J_z = 0$ channel. Particularly
problematic is the $\gamma \gamma \rightarrow c\overline{c} g \rightarrow 2$
jets process. The effects of imposing additional cuts are investigated and it
is shown that the radiative background could be reduced to a manageable level.


title:
Quantum Interference and Monte-Carlo Simulations of Multiparticle
  Production

abstract:
  We show that the effects of quantum interference can be implemented in
Monte-Carlo generators by modelling the generalized Wigner functions. A
specific prescription for an appropriate modification of the weights of events
produced by standard generators is proposed.


title:
Determination of the Higgs boson mass by the cancellation of ultraviolet
  divergencies in the $SU(2)_L\times U(1)_Y$ Theory

abstract:
  We assume the vanishing of the quadratic divergences in the $SU(2)_L \otimes
U(1)$ electroweak theory. Using $\,$ the $\,$ top $\,$ mass $\,$ value reported
recently by the CDF Collaboration $m_t = 176 \pm 8 \pm 10 GeV$, we predict the
mass of the Higgs boson to be $m_H = 321 \pm 29 GeV$. If we assume the
vanishing of both quadratic and logarithmic divergencies of the top self-mass,
we predict $m_t = 170.5 \pm 0.3 GeV $ and $m_H = 308.6 \pm 0.7 GeV.$


title: Remarks on the $W$ propagator at the resonance

abstract:
  We address the problem of properly defining the $W^{\pm}, Z^0$ propagator in
the resonance region. Particular attention is paid to the longitudinal piece of
this propagator. We also discuss the related renormalization procedures and the
unitarity property.


title: Knots and Numbers in $\phi^4$ Theory to 7 Loops and Beyond

abstract:
  We evaluate all the primitive divergences contributing to the 7--loop
$\beta$\/--function of $\phi^4$ theory, i.e.\ all 59 diagrams that are free of
subdivergences and hence give scheme--independent contributions. Guided by the
association of diagrams with knots, we obtain analytical results for 56
diagrams. The remaining three diagrams, associated with the knots $10_{124}$,
$10_{139}$, and $10_{152}$, are evaluated numerically, to 10 sf. Only one
satellite knot with 11 crossings is encountered and the transcendental number
associated with it is found. Thus we achieve an analytical result for the
6--loop contributions, and a numerical result at 7 loops that is accurate to
one part in $10^{11}$. The series of `zig--zag' counterterms,
$\{6\zeta_3,\,20\zeta_5,\, \frac{441}{8}\zeta_7,\,168\zeta_9,\,\ldots\}$,
previously known for $n=3,4,5,6$ loops, is evaluated to 10 loops, corresponding
to 17 crossings, revealing that the $n$\/--loop zig--zag term is $4C_{n-1}
\sum_{p>0}\frac{(-1)^{p n - n}}{p^{2n-3}}$, where $C_n=\frac{1}{n+1}{2n \choose
n}$ are the Catalan numbers, familiar in knot theory. The investigations
reported here entailed intensive use of REDUCE, to generate ${\rm O}(10^4)$
lines of code for multiple precision FORTRAN computations, enabled by Bailey's
MPFUN routines, running for ${\rm O}(10^3)$ CPUhours on DecAlpha machines.


title: In Search for Signs of Chaos in Branching Processes

abstract:
  For systems that involve particle production through branching processes the
concept of chaos is explored. The measures that can describe their behaviors
are investigated. Monte Carlo simulation is used to generate events according
to perturbative QCD and an Abelian model. It is shown how the measures proposed
distinguish the two cases in ways that characterize the chaotic behavior.


title: The Pion-Nucleon Coupling Constant in QCD Sum Rules

abstract:
  The pion-nucleon coupling constant $g_{\pi N}$ is studied on the basis of the
QCD sum rules. Both the Borel sum rules and the finite energy sum rules for
$g_{\pi N}$ are used to examine the effects of higher dimensional operators (up
to dim. 7) and $\alpha_s$ corrections in the operator product expansion.
Agreement with the experimental number is reached only when $S_{\pi}/S_N$ is
greater than one, where $S_{\pi}$ ($S_N$) is the continuum threshold for the
$g_{\pi N}$ (nucleon) sum rule.


title: Preasymptotic nature of hadron scattering vs small-x HERA Data

abstract:
  We emphasize that recently observed regularities in hadron interactions and
deep-inelastic scattering are of preasymptotic nature and it is impossible to
make conclusions on the true asymptotic behavior of observables without
unitarization procedure. Unitarization is important and changes scattering
picture drastically.


title:
The photon-photon interaction at low $x$ in the theory of reggeized
  gluons with a running coupling and $N_{c}\to\infty$

abstract:
  The forward elastic amplitude for scattering of real and weakly virtual
photons is studied in the framework of the theory of reggeized gluons, with
large $N_{c}$ and a running coupling constant introduced in the manner which
preserves the bootstrap condition. Transition from a single to multiple pomeron
exchanges is observed as $x$ gets smaller. For very low $x$ the amplitude
aquires an eikonal form. The photon structure function reveals a strong
violation of scaling: it grows as $Q^{2}$. As a function of $x$ it behaves as
$(\ln(1/x)\ln\ln(1/x))^{2}$. Correspondingly the cross-section for physical
photons grows with energy as $(\ln s\ln\ln s)^{2}$. Hadronic structure
functions and cross-sections are also briefly discussed.


title: Small $x$ Behaviour of Parton Distributions in Proton

abstract:
  The paper presents the $QCD$ description of the hard and semihard processes
in the framework of the Wilson operator product expansion. The smooth
transition between the cases of the soft and hard Pomerons is obtained.


title: SEMIANALYTIC DISTRIBUTIONS IN FOUR FERMION NEUTRAL CURRENT PROCESSES

abstract:
  Analytical formulae for triple differential distributions ${\rm
d}^3\sigma/({\rm d}\cos\theta{\rm d}s_1{\rm d}s_2)$ in the neutral current
process $e^+e^-\rightarrow f_1\bar f_1 f_2\bar f_2$ are given. They allow to
obtain angular distributions, rapidity distributions and transversal momentum
distributions of one fermion pair by only two numerical integrations. Cuts can
be applied to the integration variables.


title: Baryon and Lepton Number Assignment in $E_6$ Models

abstract:
  In $E_6$ models there are new particles whose baryon number is not uniquely
assigned. We point out that the baryon and lepton number assignment to these
particles can change the baryogenesis scenario significantly. We consider
left-right symmetric extension of the standard model in which $(B-L)$ quantum
number is gauged. The identification of $(B-L)$ with a generator of $E_6$ is
used to define the baryon and lepton numbers for the exotic particles in a way
that the electroweak baryon and lepton number anomaly corresponding to the
$SU(2)_L$ group vanishes, {\it i.e.}, there is no non-perturbative baryon or
lepton number violation during the electroweak phase transition. We study some
consequences of the new assignment.


title: FINAL STATE INTERACTIONS OF $B\to DK$ DECAYS

abstract:
  We study the final state strong interactions of the $B\rightarrow DK$ decay
processes, using the Regge model. We conclude that the final state interaction
phases are very small, typically a few degrees. Neglecting final state
interactions in obtaining the weak decay amplitudes is a good approximation.


title:
Analysis of data on low energy piN-->pipiN reaction. I. Total cross
  sections

abstract:
  This is the first of a series of papers on a consistent model independent
analysis of the complete experimental information on the reaction $\pi N
\rightarrow \pi \pi N$ at pion momenta up to 500 MeV/c. The paper summarizes
the theoretical approach and details of the computational procedure. The
complete database on total cross sections in 5 $\pi \pi N$ channels is given
together with a critical discussion of their model independent analysis.


title:
Branching Ratios in Proton Antiproton Annihilation at Rest from Large Nc
  QCD

abstract:
  We use classical or large Nc QCD to describe the mesons (pion, rho, omega)
coming from proton-antiproton annihilation at rest as classical fields, which
we then quantize as coherent states. This treatment gives a nearly parameter
free account of the pion branching ratios in annihilation.


title:
Electromagnetic Form Factors of the SU(3) Octet Baryons in the
  semibosonized SU(3) Nambu-Jona-Lasinio Model

abstract:
  The electromagnetic form factors of the SU(3) octet baryons are investigated
in the semibosonized SU(3) Nambu--Jona-Lasinio model (chiral quark-soliton
model). The rotational $1/N_c$ and strange quark mass corrections in linear
order are taken into account. The electromagnetic charge radii of the nucleon
and magnetic moments are also evaluated. It turns out that the model is in a
remarkable good agreement with the experimental data.


title:
Finite Supersymmetric Threshold Corrections to CKM Matrix Elements in
  the Large $tan\beta$ Regime

abstract:
  We evaluate the finite 1-loop threshold corrections, proportional to
$tan\beta$, to the down quark mass matrix. These result in corrections to down
quark masses and to Cabibbo-Kobayashi-Maskawa [CKM] matrix elements. The
corrections to CKM matrix elements are the novel feature of this paper. For
grand unified theories with large $\tan\beta$ these corrections may
significantly alter the low energy predictions of four of the CKM matrix
elements and the Jarlskog parameter J, a measure of CP violation. The angles
$\alpha,\: \beta$ and $\gamma$ of the unitarity triangle and the ratio
$|{V_{ub} \over V_{cb}}|$, however, are not corrected to this order. We also
discuss these corrections in the light of recent models for fermion masses.
Here the corrections may be useful in selecting among the various models.
Moreover, if one model fits the data, it will only do so for a particular range
of SUSY parameters.


title: Comments on the Characteristic Measurables of the Quark Mixing Matrix

abstract:
  Within the standard electroweak model we point out that the $3\times 3$
matrix of quark mixing is characterized by three universal
(rephasing-invariant) quantities: one of them for $CP$ violation and the other
two for off-diagonal asymmetries. Unitarity of the quark mixing matrix can in
principle be tested through a variety of measurements which are irrelevant to
the existence of $CP$-violating effects.


title: Quark and gluon jet spectra in $\gamma\gamma$ collisions

abstract:
  We consider three jet production at high $p_T$ in the $\gamma\gamma \to q
\bar q g$ process and calculate quark and gluon jet spectra. The possibility of
quark-gluon jet separation is discussed and compared with the $e^+ e^- \to q
\bar q g$ case.


title:
Study of the properties of dense nuclear matter and application to some
  astrophysical systems

abstract:
  The highlights and main results of this work can be summarized as follows :
(1) The energy per nucleon of cold nuclear matter, derived by us using chiral
sigma model, is in good agreement with the preliminary estimates inferred from
heavy-ion collision data in the density range between one to four times the
nuclear saturation density. (2) For a system of high density nuclear matter,
based on the chiral sigma model, we find that a strict first order phase
transition to quark matter is not favoured. This does not, of course, preclude
a phase transition of second order. However, we have not investigated the
latter problem. (3) The mass formulae for finite lumps of strange quark matter
with $u,~d$ and $s$ quarks and non-strange quark matter are derived in a
non-relativistic approach, taking into account the finite size effects such as
surface and curvature. We find that there is a good possibility for the
formation of metastable strangelets of large mass detectable in experiment. (4)
The maximum mass for stable neutron stars predicted by our equation of state
for ($n,~p,~e$) matter is 2.59 times the solar mass. The corresponding radius
($R$), crustal length ($\Delta$) and surface red shift ratio ($\alpha$) are
14.03 $km$, 1.0 $km$ and 0.674 respectively. The maximum moment of inertia is
$4.79 \times 10^{45}~g~cm^{2}$. These suggest that our equation of state for
neutron star matter is comparatively ``stiff". (5) The neutrino emissivity from
two and three flavour quark matter is numerically calculated and compared with
the result given by Iwamoto. We find that the emissivity is smaller than
Iwamoto's result by about two orders of magnitude when
$p_{f}(u)+p_{f}(e)-p_{f}(d(s))$ is comparable to the temperature. We attribute
this to the severe restriction imposed by momentum conservation on the phase


title: The Weak-Scale Hierarchy and Discrete Symmetries

abstract:
  In the underlying Planck scale theory we introduce a certain type of discrete
symmetry, which potentially brings the stability of the weak-scale hierarchy
under control. Under the discrete symmetry the $\mu $-problem and the tadpole
problem can be solved simultaneously without relying on some fine-tuning of
parameters. Instead, it is required that doublet Higgs and color-triplet Higgs
fields reside in different irreducible representations of the gauge symmetry
group at the Planck scale and that they have distinct charges of the discrete
symmetry group.


title:
Implications of the Recent Top Quark Discovery on Two Higgs Doublet
  Model

abstract:
  Concentrating on the impact of the very recent top quark discovery, we
perform a combined analysis of two strongest constraints on the 2 Higgs doublet
model, one coming from the recent measurement by CLEO on the inclusive
branching ratio of b->s \gamma decay and the other from the recent LEP data on
Z->b b-bar decay. We have included the model predictions for one-loop vertex
corrections to Z->b b-bar through $\epsilon_b$. We find that the $\epsilon_b$
constraint excludes most of the less appealing window $\tan\beta\lsim 1$ at 95%
C.L. for the measured top mass from CDF, mt=176+/- 8+/-10 GeV. Moreover, it
excludes $\tan\beta\lsim 2$ at 95% C.L. for mt>176 GeV. Combining with the b->s
\gamma constraint, only very heavy charged Higgs (>670 GeV) is allowed by the
measured mt from CDF.


title: Neutrino Oscillations by Interaction with Moduli

abstract:
  We would like to point out the possibility to detect the low-energy signals
of moduli in the superstring theory in the neutrino oscillation. The idea is
based on the characteristics that the couplings of moduli are different in
matter. We estimate the oscillation probability both in the long baseline and
in the solar neutrino oscillations and examine the detectable region of the
moduli effect.


title: Selection Rules for Nonrenormalizable Couplings in Superstring Theories

abstract:
  We study nonrenormalizable coupling terms in $Z_N$ orbifold models.
Nontrivial selection rules of couplings are provided and cannot be understood
in terms of a simple symmetry of effective field theories. We also discuss
phenomenological implications of theses selection rules for the quark mass
matrices.


title: UNDERSTANDING THE SCALAR MESON $q\bar q$ NONET

abstract:
  It is shown that one can fit the available data on the a0(980), f0(980),
f0(1300) and K*0(1430) mesons as a distorted 0++ qq bar nonet using very few
(5-6) parameters and an improved version of the unitarized quark model. This
includes all light two-pseudoscalar thresholds, constraints from Adler zeroes,
flavour symmetric couplings, unitarity and physically acceptable analyticity.
The parameters include a bare uu bar or dd bar mass, an over-all coupling
constant, a cutoff and a strange quark mass of 100 MeV, which is in accord with
expectations from the quark model.
  It is found that in particular for the a0(980) and f0(980) the KK bar
component in the wave function is large, i.e., for a large fraction of the time
the qq bar state is transformed into a virtual KK bar pair. This KK bar
component, together with a similar component of eta' pi for the a0(980) , and
eta eta, eta eta' and eta' eta' components for the f0(980), causes the
substantial shift to a lower mass than what is naively expected from the qq bar
component alone.
  Mass, width and mixing parameters, including sheet and pole positions, of the
four resonances are given, with a detailed pedagogical discussion of their
meaning.


title: Hadronic Flavor and CP Violating Signals of Superunification

abstract:
  The flavor changing and CP violating phenomena predicted in supersymmetric
unified theories as a consequence of the large top quark Yukawa coupling, are
investigated in the quark sector and compared with related phenomena in the
lepton sector, considered previously. In particular we study $\varepsilon_K$,
$\varepsilon_K'/\varepsilon_K$, $\Delta m_B$, $b\to s\gamma$, the neutron
electric dipole moment, $d_n$, and CP violation in neutral $B$ meson decays,
both in minimal~SU(5) and~SO(10) theories. The leptonic signals are generically
shown to provide more significant tests of quark-lepton unification.
Nevertheless, mostly in the~SO(10) case, a variety of hadronic signals is also
possible, with interesting correlations among them.


title: A PARTON MODEL FOR DIFFRACTIVE PROCESSES IN DEEP INELASTIC SCATTERING

abstract:
  We demonstrate that the global properties of the ``rapidity gap'' events,
observed at HERA, can be understood based on electron-gluon scattering as the
underlying partonic process. Using the measured inclusive structure function
$F_2$ to determine the parameters of the parton model, the diffractive
structure function $F_2^D$ is predicted. The ratio of diffractive and inclusive
cross sections, $R_D = \sigma_D/\sigma_{incl}\simeq 1/9$, is determined by the
probability of the produced quark-antiquark pair to evolve into a colour
singlet state. This colour singlet cluster may fragment into hadrons
independently of the proton remnant, yielding the observed gap in rapidity.


title: Inclusive Semileptonic Decays and the Structure of B Mesons

abstract:
  A field theoretic description for inclusive semileptonic B meson decays is
formulated. We argue that large regions of the phase spaces for the decays are
dominated by distances near the light cone. The light-cone dominance allows to
incorporate nonperturbative QCD effects in a distribution function. A
one-to-one correspondence with the heavy quark effective theory is developed,
which can estimate the first two moments of the distribution function. These
conditions are useful but not restrictive enough to specify the distribution
function, which must still be determined from experiment. Several
model-independent predictions, such as scaling, sum rules of the hadronic
structure functions and relations among them, are made. General formulas for
the differential decay rates on several variables are presented, which are used
for calculating the electron energy spectra with an Ansatz for the light-cone
distribution function.


title:
Prediction of the anomalous magnetic moment of nucleon from the nucleon
  anomaly

abstract:
  We construct the effective anomaly lagrangian involving nucleons and photons
by using current-current coupling method. The contribution of this lagrangian
to the anomalous magnetic moment of nucleon is purely isovector. The anomalous
magnetic moment of proton, $\kappa_P$, can be calculated from the this
lagrangian and it is found to be $\kappa_P^{Theor.} = 1.77$, which is in
excellent agreement with the experimental value $\kappa_P^{Exp.} = 1.79$. While
the case of neutron, $\kappa_N^{Theor.} = -2.58$ as compared to
$\kappa_N^{Exp.} =-1.91$, is less satisfactory, but the sign is correct.


title:
SPIN-DEPENDENT NUCLEAR STRUCTURE FUNCTIONS: GENERAL APPROACH WITH
  APPLICATION TO THE DEUTERON

abstract:
  We study deep-inelastic scattering from polarized nuclei within a covariant
framework. A clear connection is established between relativistic and
non-relativistic limits, which enables a rigorous derivation of convolution
formulae for the spin-dependent nuclear structure functions g_1^A and g_2^A in
terms of off-mass-shell extrapolations of polarized nucleon structure
functions, g_1^N and g_2^N. Approximate expressions for g_{1,2}^A are obtained
by expanding the off-shell g_{1,2}^N about their on-shell limits. As an
application of the formalism we consider nuclear effects in the deuteron,
knowledge of which is necessary to obtain accurate information on the
spin-dependent structure functions of the neutron.


title: HIGGS BOSON PRODUCTION AT THE LHC

abstract:
  Gluon fusion is the main production mechanism for Higgs particles at the LHC.
We present the QCD corrections to the fusion cross sections for the Higgs boson
in the Standard Model, and for the neutral Higgs bosons in the minimal
supersymmetric extension of the Standard Model. The QCD corrections are in
general large and they increase the cross sections significantly. In two steps
preceding the calculation of the production processes, we determine the QCD
radiative corrections to Higgs decays into two photons and gluons.


title:
The Relative $J/\Psi$ to $\Psi'$ Suppression in Proton-Nucleus and
  Nucleus-Nucleus Collisions

abstract:
  We calculate the nuclear suppression for $J/\Psi$ and $\Psi'$ production
within a coupled channel approach in the subspace of the $J/\Psi$ and $\Psi'$
states. We are able to explain, why (i) the $J/\Psi$ and $\Psi'$ show the same
suppression from $200\ GeV$ to $800\ GeV$ in proton-nucleus collisions and why
(ii) the $\Psi'$ is absorbed more strongly than the $J/\Psi$ in nucleus-nucleus
collisions at $200\ GeV$. The numerical result which includes only interactions
with nucleons acconts for half of the observed suppression in sulphur-uranium
collisions.


title: Nuclear Shadowing and the Proton Structure Function at Small x

abstract:
  A new scaling variable is introduced in terms of which nuclear shadowing in
deep-inelastic scattering is universal, i.e. independent of $A$, $Q^2$ and $x$.
This variable can be interpreted as a measure of the number of gluons probed by
the hadronic fluctuations of a virtual photon during their lifetime. According
to recent data from the H1 and ZEUS experiments, the gluon density in a proton
rises steeply as $x$ tends to zero. So nuclei which in the infinite momentum
frame have a large surface density of gluons model at larger $x$ values what we
expect for the proton at much smaller $x$. Using experimental information on
nuclear shadowing we predict the unitarity corrections to the proton structure
function at small $x$ and extract the bare Pomeron intercept.


title: Mass hierarchy and the spectrum of scalars

abstract:
  We use the natural $SU(3)\times U(1)$ global symmetry of the gauge-fermion
interaction sector of the standard model to discuss the fermion mass hierarchy
problem. The $SU(3)$ sixtet and triplet Higgs are introduced.
  The Yukawa sector is partially symmetric. The smaller the symmetry of a
Yukawa term, the smaller its coupling constant. The mass hierarchy is a
combined effect of smaller coupling constants and smaller VEVs. There is a
bunch of pseudo-goldstone bosons which obtains their masses mainly from the
small explicit breaking terms in the Higgs potential.


title: Standard Model Higher Order Corrections to the WW\gamma/WWZ Vertex

abstract:
  Using the S--matrix pinch technique we obtain to one loop order gauge
independent $\gamma W^-W^+$ and $Z W^-W^+$ vertices in the context of the
standard model, with all incoming momenta off--shell. We show that the vertices
so constructed satisfy simple QED--like Ward identities. These gauge invariant
vertices give rise to expressions for the magnetic dipole and electric
quadrupole form factors of the $W$ gauge boson, which, unlike previous
treatments, satisfy the crucial properties of infrared finiteness and
perturbative unitarity.


title: The Ward Identities of the Gauge Invariant Three Boson Vertices

abstract:
  We outline the pinch technique for constructing gauge invariant Green's
functions in gauge theories and derive the Ward identities that must be
satisfied by the gauge invariant three boson vertices of the standard model.
They are generalizations of their tree level Ward identities and are shown to
be crucial for the delicate gauge cancellations of the S-matrix.


title: RECENT DEVELOPMENTS IN THE PINCH TECHNIQUE

abstract:
  Some of the most important theoretical and phenomenological aspects of the
pinch technique are presented, and several recent developments are briefly
reviewed.


title: EVIDENCE FOR ELECTROWEAK CORRECTIONS IN THE STANDARD MODEL

abstract:
  The phenomenological evidence for electroweak corrections in the Standard
Model, both at very low energies and the $Z^0$ scale, is discussed. In
particular, we review a simple but sharp argument for the presence of
Electroweak Bosonic Corrections.


title: CP violation in the Weinberg multi-Higgs model

abstract:
  We report new results in the study of CP violation in semileptonic top
decays, in the context of the Weinberg Model.


title:
B Factory Constraints on Isosinglet Down Quark Mixing, and Predictions
  For Other CP Violating Experiments

abstract:
  In the main part of the paper we project forward to having $B$ factory
determinations of $\sin(2\beta)$ and $\sin(2\alpha)$, for which we take several
values. First, we use a joint $\chi^2$ analysis of CKM experiments to constrain
CKM matrix elements in the standard model, and experiments on the angles
$\alpha$, $\beta$, and $\gamma$, and on $x_s$ and null $CP$ asymmetries. Then
we invoke mixing to a new isosinglet down quark (as in E$_6$) which induces
FCNC that allow a $Z^0$ mediated contribution to $B-\bar B$ mixing and which
brings in new phases. We then repeat the $\chi^2$ analysis, now including
experimental constraints from FCNC as well, finding much larger ranges of
prediction for the $B$ factory. We then add projected $B$ factory results on
$\sin(2\beta)$ and $\sin(2\alpha)$ and repeat both analyses. In $(\rho,\eta)$
and $(x_s,\sin{(\gamma)})$ plots for the extra isosinglet down quark model, we
find multiple regions that will require experiments on $\sin{(\gamma)}$ and/or
$x_s$ to decide between and possibly to effectively bound out the extra down
quark contribution.


title: ON THE INTRINSIC CHARM COMPONENT OF THE NUCLEON

abstract:
  Using a $\overline D$ meson cloud model we calculate the squared charm radius
of the nucleon . The ratio between this squared radius and the ordinary baryon
squared radius is identified with the probability of ``seeing'' the intrinsic
charm component of the nucleon. Our estimate is compatible with those used to
successfully describe the charm production phenomenology.


title:
Strong-coupling expansions for chiral models of electroweak symmetry
  breaking

abstract:
  We consider chiral $U(N)\times U(N)$ models with fermions in the limit of
infinitely large local bare Yukawa coupling. When the scalar field is subject
to non-linear constraint, phase transitions in these models are seen to be
identical to those in the corresponding purely bosonic ones. Relaxing the
non-linear constraint, we compute the seventh-order strong-coupling series for
the susceptibility in these models and analyze them numerically for the
$U(2)\times U(2)$ case. We find that in four dimensions the approach to the
phase transition follows to a good accuracy the mean-field critical behavior,
indicating the absence of non-trivial fixed points at strong coupling and being
consistent with the first-order nature of the transition. In three dimensions,
the strongly-coupled bosonic $U(2)\times U(2)$ model (without gauge fields) has
a first-order transition strong enough to accommodate electroweak baryogenesis
only for a narrow region of the bare parameter space.


title:
Precision Study of Minimal Supersymmetric Standard Model by production
  and decay of scalar tau lepton

abstract:
  Study of the production and decay of scalar tau lepton ($\st$) at future
$\epem$ colliders helps to determine the value of $\tan\beta$ through the
measurement of the polarization of $\tau$ lepton that arises from $\st$ decay.
Key maps of the parameter space of MSSM are presented. (talk presented at the
fifth workshop on Japan Linear Collider(JLC) at Kawatabi, Feb 16-17.)


title:
Particle Production in Very High-Energy Cosmic-Ray Emulsion Chamber
  Events: Usual and Unusual Events

abstract:
  We show that a simple scaling model of very forward particle production,
consistent with accelerator and air shower data, can describe all features of
the very high-energy interactions recorded with emulsion chambers. This is
somewhat surprising after numerous claims that the same data implied large
scaling violations or new dynamics. Interestingly, we cannot describe some of
the Centauro events, suggesting that these events are anomalous independently
of their well-advertised unusual features such as the absence of neutral
secondaries.


title: OVERVIEW OF KAON DECAY PHYSICS

abstract:
  After a brief history of the insights gained from Kaon physics, the potential
of Kaon decays for probing lepton number violation is discussed. Present tests
of CTP and of Quantum Mechanics in the neutral Kaon sector are then reviewed
and the potential of the Frascati $\Phi$ factory for doing incisive tests in
this area is emphasized. The rest of this overview focuses on CP violating
effects in the Kaon system. Although present observations of CP violation are
perfectly consistent with the CKM model, we emphasize the theoretical and
experimental difficulties which must be faced to establish this conclusively.
In so doing, theoretical predictions and experimental prospects for detecting
$\Delta S=1$ CP violation through measurements of $\epsilon^\prime/\epsilon$
and of rare K decays are reviewed. The importance of looking for evidence for
non-CKM CP-violating phases, through a search for a non-vanishing transverse
muon polarization in $K_{\mu 3}$ decays, is also stressed.


title:
Third family flavor physics in an SU(3)^3 \times SU(2)_L \times U(1)_Y
  model

abstract:
  We consider a model in which each family transforms under a different SU(3)
color group. The low-energy effective theory is an extension of the Standard
Model, with additional color octet gauge bosons $G_H$ with mass $M$ that couple
preferentially to the third family quarks. We show that there are two distinct
regions of the model's parameter space in which we can simultaneously evade all
the current experimental constraints, one with $M \approx 250$ GeV and the
other with $M \gtrsim 600$ GeV. Within each allowed region, we can obtain a
correction to the $Zb\overline{b}$ vertex that is consistent with the slightly
high value of $R_b$ observed at LEP. We show that there are $\Delta B = 1$
operators in our model that can suppress the $B$-meson semileptonic branching
ratio $B_{SL}$ and the charm multiplicity per decay $n_c$ by enough to
reconcile the spectator parton model predictions with the experimental data. In
the non-supersymmetric version of our model, we can only obtain the desired
corrections to $R_b$, $B_{SL}$ and $n_c$ in different regions of the allowed
parameter space, while in the supersymmetric version, we can obtain all three
corrections simultaneously. We also discuss a strong-coupling limit of our
model in which the third-family quarks become composite.


title:
THE LARGE MOMENTUM TRANSFER BEHAVIOUR OF MESON-PHOTON TRANSITION FORM
  FACTORS

abstract:
  It is reported on predictions for the $\pi$-$\gamma$ transition form factor
obtained within a perturbative approach which includes transverse momentum
effects and Sudakov corrections. The results clearly favor distribution
amplitudes close to the asymptotic form, $\sim x_1x_2$, and disfavor
distribution amplitudes which are strongly concentrated in the end-point
regions. Applications of that approach to the $\eta$-$\gamma$ and
$\eta^\prime$-$\gamma$ transition form factors are discussed as well.


title: Chaotic Inflation based on an Abelian D-flat Direction

abstract:
  We study the inflation due to the D-flat direction of an extra $U(1)$. This
scenario is a hybrid of a right-handed sneutrino inflaton scenario and a gauge
non-singlet inflaton scenario. The inflaton is a gauge non-singlet field which
induces a right-handed neutrino mass spontaneously through an extra $U(1)$
D-flat direction. This right-handed neutrino mass can explain the solar
neutrino problem. The reheating temperature resulting from the decay of the
coherent oscillation of the right-handed sneutrino is sufficiently high so that
the baryogenesis based on the lepton number asymmetry can be applicable. We
also discuss the realistic model building.


title: COVARIANT SINGLE-TIME BOUND-STATE EQUATION

abstract:
  We derive a system of covariant single-time equations for a two-body bound
state in a model of scalar fields $\phi_1$ and $\phi_2$ interacting via
exchange of another scalar field $\chi$. The derivation of the system of
equations follows from the Haag expansion. The equations are linear integral
equations that are explicitly symmetric in the masses, $m_1$ and $m_2$, of the
scalar fields, $\phi_1$ and $\phi_2$. We present an approximate analytic
formula for the mass eigenvalue of the ground state and give numerical results
for the amplitudes for a choice of constituent and exchanged particle masses.


title: Charmonium Interactions in Nuclear Matter

abstract:
  We analyse the kinematic regimes attainable for $J/\Psi$ and $\Psi'$
production in $p-A$ collisions. With this information, we specify the
requirements for an experiment to study the interaction of physical charmonium
states in nuclear matter, making use of a heavy ion beam incident on a hydrogen
or deuterium target.


title:
Three-loop QED Vacuum Polarization and the Four--loop Muon Anomalous
  Magnetic Moment

abstract:
  Three--loop contributions to massive QED vacuum polarization are evaluated by
a combination of analytical and numerical techniques. The first three Taylor
coefficients, at small $q^2$, are obtained analytically, using
$d$\/--dimensional recurrence relations. Combining these with analytical input
at threshold, and at large $q^2$, an accurate Pad\'e approximation is obtained,
for all $q^2$. Inserting this in the one--loop diagram for the muon anomalous
magnetic moment, we find reasonable agreement with four--loop,
single--electron--loop, muon--anomaly contributions, recently re--evaluated by
Kinoshita, using 8--dimensional Monte--Carlo integration. We believe that our
new method is at least two orders of magnitude more accurate than the
Monte--Carlo approach, whose uncertainties appear to have been underestimated,
by a factor of 6.