title: $K\to\pi\nu\bar\nu$ and High Precision Determinations of the CKM Matrix

abstract:
  We investigate the future determination of the CKM matrix using theoretically
clean quantities, like $B(K^+\to\pi^+\nu\bar\nu)$, $B(K_L\to\pi^0\nu\bar\nu)$
or $\sin 2\beta$, $\sin 2\alpha$ as extracted from CP violation studies in $B$
physics. The theoretical status of $K\to\pi\nu\bar\nu$ is briefly reviewed and
their phenomenological potential is compared with that of CP asymmetries in $B$
decays. We stress the unique opportunities provided by measuring the CP
violating rare decay $K_L\to\pi^0\nu\bar\nu$. It is pointed out that this mode
is likely to offer the most precise determination of ${\rm Im}V^*_{ts}V_{td}$
and the Jarlskog parameter $J_{CP}$, the invariant measure of CP violation in
the Standard Model.


title: Goldstino Decoupling in Spontaneously Broken Supergravity Theories

abstract:
  If the gravitino is sufficiently light and stable it will behave as an
effective massless neutrino species at the time of nucleosynthesis. Depending
on the temperature at which it decouples from the thermal bath in the early
universe, the gravitino mass will be bounded by the primordial $^4$He
abundance. Assuming a conservative estimate that the number of neutrino
families, $N_\nu < 3.6$, superlight gravitinos with a mass $m_{3/2} \lesssim
10^{-6}$eV are ruled out. This bound is weaker than previous estimates because
the Goldstino annihilation cross section was overestimated.


title: Bounding CPT Violation in the Neutral-B System

abstract:
  The feasibility of placing bounds on CPT violation from experiments with
neutral-$B$ mesons is examined. We consider situations with uncorrelated mesons
and ones with either unboosted or boosted correlated mesons. Analytical
expressions valid for small T- and CPT-violating parameters are presented for
time-dependent and time-integrated decay rates, and various relevant
asymmetries are derived. We use Monte-Carlo simulations to model experimental
conditions for a plausible range of CPT-violating parameters. The treatment
uses realistic data incorporating background effects, resolutions, and
acceptances for typical detectors at LEP, CESR, and the future $B$ factories.
Presently, there are no bounds on CPT violation in the $B$ system. We
demonstrate that limits of order 10\% on CPT violation can be obtained from
data already extant, and we determine the CPT reach attainable within the next
few years.


title: Phenomenological Implications of Low Energy Supersymmetry Breaking

abstract:
  The experimental signatures for low energy supersymmetry breaking are
presented. The lightest standard model superpartner is unstable and decays to
its partner plus a Goldstino, $G$. For a supersymmetry breaking scale below a
few 1000 TeV this decay can take place within a detector, leading to very
distinctive signatures. If a neutralino is the lightest standard model
superpartner it decays by $\chi_1^0 \to \gamma + G$, and if kinematically
accessible by $\chi_1^0 \to (Z^0, h^0, H^0, A^0) + G$. These decays can give
rise to displaced vertices. Alternately, if a slepton is the lightest standard
model superpartner it decays by $\tilde{l} \to l + G$. This can be seen as a
greater than minimum ionizing charged particle track, possibly with a kink to a
minimum ionizing track.


title:
Generalized Pinch Technique and the Background Field Method in General
  Gauges

abstract:
  It is shown that Cornwall's pinch technique can be extended in a consistent
diagrammatic way, so as to describe general background field gauges in
Yang-Mills theories. The resulting one-loop Green's functions are found to obey
Ward identities identical to those derived from the classical action at the
tree level. This generalization of the pinch technique may hence be related to
the background field method implemented with novel gauge-fixing conditions
invariant under background field gauge transformations. To one loop, the
connection between the generalized pinch technique and the background field
method in covariant and in non-covariant gauges is explicitly demonstrated.


title: Dispersion Analysis of the Strange Vector Form Factors of the Nucleon

abstract:
  We analyze the nucleon matrix element of the strange quark vector current in
a nucleon--model independent dispersive approach with input from the current
world data set for the isoscalar electromagnetic form factors. The update of
Jaffe's minimal 3-pole ansatz for the spectral functions yields a 40% larger
(Sachs) strangeness radius, $(r_s^2)_{Sachs} = 0.20 {\rm fm}^2$, and a by 20%
reduced magnitude of the strangeness magnetic moment, $\mu_s = -0.26$. In the
pole approximation these values are shown to be upper bounds. After extending
the ansatz in order to implement the asymptotic QCD momentum dependence (which
the 3-pole form factors cannot reproduce), we find the magnitude of the 3-pole
results reduced by up to a factor of 2.5. The signs of the leading moments
originate primarily from the large $\phi$-meson couplings and are generic in
the pole approximation.


title: Lepton Flavor Violation at LEP II and Beyond

abstract:
  If sleptons are produced at LEP II or the Next Linear Collider, lepton flavor
violation can be probed at a level significantly below the current bounds from
rare processes, such as $\mu \to e\gamma$. Polarizable $e^-$ beams and the
$e^-e^-$ mode at the NLC are found to be powerful options.


title: CIRCE Version 1.0: Beam Spectra for Linear Collider Physics

abstract:
  I describe parameterizations of realistic $e^\pm$- and $\gamma$-beam spectra
at future linear $e^+e^-$-colliders. Emphasis is put on simplicity and
reproducibility of the parameterizations, supporting reproducible physics
simulations. The parameterizations are implemented in a library of distribution
functions and event generators.


title: Two-loop effects of enhanced electroweak strength in the Higgs sector

abstract:
  The selfcoupling of the Higgs field grows with the mass of the Higgs particle
and induces potentially large radiative corrections in the electroweak model.
The technical aspects of performing multiloop calculations in the massive case
are discussed briefly. I review the status of two-loop calculations of
radiative corrections of enhanced electroweak strength which are relevant for
the Higgs physics. I discuss the relevance of the existing results with respect
to heavy Higgs searches at future colliders and their implications regarding
the validity range of perturbation theory.


title:
Cold Strangelets Formation with Finite Size Effects in High Energy
  Heavy-Ion Collisions

abstract:
  We have studied the phase diagram and evolution of a strangelet in
equilibrium with a finite hadronic gas. Significant finite size modifications
of the phase diagram are found and their parameter dependences are studied.
With the inclusion of finite size effects we have also been able to obtain the
detailed properties of the cold strangelet emerging in the final stage of the
isentropic expansion of a finite strange fireball in high energy heavy-ion
collisions.


title:
Low Temperature Dominance of Pion-like Excitations in the Massive
  Gross-Neveu Model at Order 1/N

abstract:
  We perform a 1/N-expansion of the partition function of the massive
Gross-Neveu model in 1+1 dimensions. The procedure allows for the inclusion of
the contribution of scalar and pseudoscalar composites (of order 1/N) to the
equation of state. The naive expectation that the bosonic fluctuations correct
significantly the mean field approximation at low temperatures is confirmed by
our calculations. Actually the relevant degrees of freedom of hadronic matter
at low temperatures are found to be pion-like excitations, rather than the
fundamental constituents.


title: Propagating Higgs Boundstates in SUSY

abstract:
  The possibilities for an underlying theory behind an effective supersymmetric
Nambu--Jona-Lasinio like model of electroweak symmetry breaking with
propagating Higgs boundstates (e.g. supersymmetric topcondensation) are
investigated. The concept of a renormalizable underlying theory turns out not
to be appropriate. We argue that the new theory should come from the Planck
scale and be connected to supergravity. Such a model can be constructed but
necessarily implies a nonlinear definition of the full Lagrangian.


title:
SU(3) Chiral Dynamics with Coupled Channels: Eta and Kaon
  Photoproduction

abstract:
  We identify the leading s-wave amplitudes of the SU(3) chiral meson-baryon
Lagrangian with an effective coupled-channel potential which is iterated in a
Lippmann-Schwinger equation. The strangeness $S=-1$ resonance $\Lambda(1405)$
and the $S_{11}(1535)$ nucleon resonance emerge as quasi-bound states of
anti-kaon/nucleon and kaon/$\Sigma$-hyperon. Our approach to meson
photoproduction introduces no new parameters. By adjusting a few finite range
parameters we are able to simultaneously describe a large amount of low energy
data. These include the cross sections of $K^-p$ elastic and inelastic
scattering, the cross sections of eta meson and kaon photoproduction from
nucleons as well as those of pion induced production of etas and kaons (16
different reaction channels altogether).


title: Neural network analysis for gamma gamma -> 3pi at Daphne

abstract:
  We consider the possibility of using neural networks in experimental data
analysis in Daphne. We analyze the process $\gamma\gamma\to \pi^+ \pi^- \pi^0$
and its backgrounds using neural networks and we compare their performances
with traditional methods of applying cuts on several kinematical variables. We
find that the neural networks are more efficient and can be of great help for
processes with small number of produced events.


title: Getting at the Quark Mass Matrices

abstract:
  We present a class of Ansatze for the up and down quark mass matrices which
leads approximately to: |V_{us}| \sim \sqrt{m_d / m_s}, |V_{cb}| \sim m_s /
m_b, and |V_{ub} / V_{cb}| \sim \sqrt{m_u / m_c}. Sizes of the
Kobayashi-Maskawa matrix elements are controlled solely by quark mass ratios.
In particular, we introduce no other small parameter and our results do not
rely on delicate cancellation.


title: Electromagnetic Contributions to Vector Meson Masses and Mixings

abstract:
  We use the 1/N_c method to estimate electromagnetic contributions to vector
meson masses and mixings. We identify several new sources of rho-omega mixing
coming from short-distance effects. We comment on the extraction of quark
masses from the vector meson masses. We also present a simple group theoretical
discussion of the electromagnetic mass differences.


title:
Non-unified gaugino masses in supersymmetric missing partner models with
  hypercolor

abstract:
  The gaugino mass relations $m_3/{g_3^2} = m_2/{g_2^2} = m_1/{g_1^2}$ are
considered to be robust signals for supersymmetric grand unification. In this
letter, we point out that these relations may be significantly modified in an
interesting class of models which solve the doublet-triplet splitting problem
using a missing partner mechanism together with a strong hypercolor gauge
group. The observation of non-unified gaugino masses, together with unified
sfermion masses, provides a distinctive signature for these models.


title: Cone Algorithm Jets in e+e- Collisions

abstract:
  The structure of hadronic jets depends not only on the dynamics of QCD but
also on the details of the jet finding algorithm and the physical process in
which the jet is produced. To study these effects in more detail we calculate
the jet cross section and the internal jet structure in e+e- annihilations and
compare them to the results found in hadronic collisions using the same jet
definition, the cone algorithm. The different structures of the overall events
in the two cases are evident in the comparison. For a given cone size and jet
energy, the distribution of energy inside the cone is more concentrated near
the center for jets from e+e- collisions than for jets from hadronic
collisions.


title: Constraints on the Minimal Supergravity Model from Non-standard Vacua

abstract:
  We evaluate regions of parameter space in the minimal supergravity model
where ``unbounded from below'' (UFB) or charge or color breaking minima (CCB)
occur. Our analysis includes the most important terms from the 1-loop effective
potential. We note a peculiar discontinuity of results depending on how
renormalization group improvement is performed: One case leads to a UFB
potential throughout the model parameter space, while the other typically
agrees quite well with similar calculations performed using only the tree level
potential. We compare our results with constraints from cosmology and
naturalness and find a preferred region of parameter space which implies
$m_{\tg}\alt 725$ GeV, $m_{\tq}\alt 650$ GeV, $m_{\tw_1}\alt 225$ GeV and
$m_{\tell_R}\alt 220$ GeV. We discuss the consequences of our results for
supersymmetry searches at various colliding beam facilities.


title:
One Loop Supersymmetric QCD Radiative Corrections to the top quark
  production in $p\bar{p}$ collisions

abstract:
  The purpose of this note is to give the one loop radiative corrections to the
top quark pair production in the $p\bar{p}$ annihilation at the Fermilab
Tevatron in the context of the Minimal Supersymmetric Model. We concentrate
here on the supersymmetric QCD corrections and give the analytic expression for
these corrections. Recently Li et. al. have reported the supersymmetric QCD
corrections to this process we indicate clearly a comparison of their and our
work. In particular, we find additional corrections [crossed box and gluon
self-energy] at the one loop level which are not given by Li et. al.. Our
numerical results disagree with the original claim of Li et. al. The numerical
values given by them in a recent erratum do agree with the general trend of our
numerical results however the actual values still disagree. We find that the
percentage corrections at the hadronic corrections changes from $22\%$ to
$-0.5\%$ as the squark mass is changed from 100 GeV to 600 GeV, for a gluino
mass of 200 GeV. For a gluino mass of 150 GeV the squark-mass dependence is
less abrupt; they change from $-5.3\%$ to $1\%$ as the squark mass is varied
between 100 GeV and 600 GeV. We also present numerical results for differential
cross section at the hadronic level, and percentage corrections at the parton
level. PACS number(s): 14.80Dq; 12.38Bx; 14.80. Gt


title: An E$_6$ interpretation of an $e^+ e^- \gamma \gamma E\!\!\!/_T$ event

abstract:
  The lowest-dimensional representation of the group E$_6$ contains both the
standard quarks and leptons and a set of exotic quarks and leptons whose decays
can involve a series of chains ending in radiative decay of one light neutrino
species to another. An example is given based on the decomposition E$_6 \to$
SU(2)$_I \times$ SU(6), where SU(2)$_I$ is an ``inert'' subgroup whose gauge
bosons $W_I^{(\pm)}$ and $Z_I$ are all electromagnetically neutral, while SU(6)
contains the conventional SU(5) grand-unified group. The possibility is
explored that such a chain is responsible for an event observed by the Collider
Detector at Fermilab (CDF) involving the production in proton-antiproton
collisions at $E_{\rm c.m.} = 1.8$ TeV of an electron-positron pair, two
photons, and missing energy ($e^+ e^- \gamma \gamma E \!\!\!/_T$).


title:
The OZI Rule Violation in $N \bar N$ Annihilation at Rest and the Skyrme
  Model

abstract:
  The question is raised if a large violation of the OZI rule, recently
observed in many channels in $N \bar N$ annihilation at rest, can be explained
in the framework of the Skyrme model.


title:
Bayesian estimate of the effect of B^0B^0bar mixing measurements on the
  CKM matrix elements

abstract:
  A method employing Bayesian statistics is used to incorporate recent
experimental results on BdBdbar and BsBsbar mixing into a measurement of the
Cabibbo-Kobayashi-Maskawa matrix elements. The neutral B meson mixing results
yield a slight improvement in the estimation of Vtd.


title: MC-Simulation of the Transverse Double Spin Asymmetry for RHIC

abstract:
  Using {\sc Sphinx tt}, a new MC simulation program for transverse polarized
nucleon--nucleon scattering based on {\sc Pythia~5.6}, we calculate the
transverse double spin asymmetry $A^{TT}$ in the Drell-Yan process. If one
assumes (quite arbitrarily) that the transversity parton distribution $\delta
q(x,Q^2)$ equals the helicity distribution $\Delta q(x,Q^2)$ at some low
$Q_0^2$ scale, the resulting asymmetry is of order 1\%. In this case is
$A^{TT}$ would hardly be be measurable with PHENIX at RHIC.


title: Non-leptonic weak decays and final state interactions in lattice QCD

abstract:
  We show that, under a reasonable "smoothness" hypothesis, it is possible to
extract informations on the amplitude and phase of two-body non-leptonic weak
decay matrix elements from the study of Euclidean correlation functions in
lattice QCD.


title: Continuous mass-dependent analysis of the non--singlet DIS data

abstract:
  We consider the issue of an accurate description of the evolution of the
non-singlet structure function moments $M_n(Q)$ near heavy quark threshold. To
this aim we propose a simple modification of the standard massless \MSbar
scheme approach to the next-to-leading QCD analysis of DIS data. We apply it to
the processing of the modern CCFR data for $xF_3$ structure function and
extract the value of $\alpha_s(M_z) \approx 0.108 \pm 0.004$ We check also the
consistency of light gluino hypothesis with CCFR data.


title:
$B \to\tau^+ \tau^- (X)$ decays: first constraints and phenomenological
  implications

abstract:
  The study of $B \to \tau^+ \tau^- (X)$ decays can provide us with a better
understanding of the third generation, and can be a useful probe of physics
beyond the standard model. We present a model independent analysis of these
decays. We classify new physics that can largely enhance the decay rates and we
discuss the constraints implied by other processes. Experimentally, flavor
changing neutral current $B$ decays into final state $\tau$'s are still
unconstrained. Searches for $B$ decays with large missing energy at LEP provide
the first limits. We estimate that existing data already imply bounds on the
$B_d \to \tau^+ \tau^-$, $B_s \to \tau^+ \tau^-$, and $B \to X \tau^+ \tau^-$
decay rates at the few percent level. Although these bounds are over four
orders of magnitude above the standard model predictions, they provide the
first constraints on some leptoquarks, and on some R-parity violating
couplings.


title: The QCD dipole picture of small-x physics

abstract:
  The QCD dipole picture of BFKL dynamics provides an attractive theoretical
approach to the study of the QCD (resummed) perturbative expansion of small-x
physics and more generally to hard high-energy processes. We discuss
applications to the phenomenology of proton structure functions in the HERA
range and to the longstanding problem of unitarity corrections, and outline
some specific predictions of the dipole picture.


title: Two Photon Couplings of Hybrid Mesons

abstract:
  A new formalism is developed for the two photon production of hybrid mesons
via intermediate hadronic decays. In an adiabatic and non-relativistic context
with spin 1 pair creation we obtain the first absolute estimates of unmixed
hybrid production strengths to be small (0.03 - 3 eV) in relation to
experimental meson widths (0.1 - 5 keV). Within this context, two photon
experiments at Babar, Cleo II, LEP2 and LHC therefore strongly discriminate
between hybrid and conventional meson wave function components, filtering out
conventional meson components. Decay widths of unmixed hybrids vanish.
Conventional meson two photon widths are roughly in agreement with experiment.


title: Have Gluonic Excitations Been Found?

abstract:
  New experimental information on the non-exotic J^PC = 0^-+ isovector seen at
1.8 GeV by VES yields convincing evidence of its excited gluonic (hybrid)
nature when a critical study of alternative quarkonium assignments is made in
the context of ^3 P_0 decay by flux-tube breaking. Production of this gluonic
excitation via meson exchange is promising, although its two photon production
vanishes.


title: Experimental results and the hypothesis of tachyonic neutrinos

abstract:
  Recent measurements of the electron and muon neutrino masses squared are
interpreted as an indication that neutrinos are faster than light particles --
tachyons. The tritium beta decay amplitude is calculated for the case of the
tachyonic electron neutrino. Agreement of the theoretical prediction with the
shape of the recently measured electron spectra is discussed. Amplitude for the
three body decay of the tachyonic neutrino, $\nu_{i} \rightarrow \nu_{i}
\nu_{j} \overline{\nu}_{j} $, is calculated. It is shown that this decay may
explain the solar neutrino problem without assuming neutrino oscillations.
Predictions for short and long baseline experiments are commented. Future
experimental activities are suggested.


title:
Renormalization conditions and non-diagrammatic approach to
  renormalizations

abstract:
  The representation of the bare parameters of Lagrangian in terms of total
vertex Green's functions is used to obtain the general form of renormalization
conditions. In the framework of this approach renormalizations can be carried
out without treatment to Feynman diagrams.


title: Diffractive DIS from the Color Dipole BFKL Pomeron

abstract:
  We review the recent progress in the theory of diffractive DIS, focusing on
predictions of strong breaking of the Ingelman-Schlein-Regge factorization and
the related breaking of the GLDAP evolution for the diffractive structure
function.


title: Fragmentation Functions approach in pQCD fragmentation phenomena

abstract:
  Next-to-leading order parton fragmentation functions into light mesons are
presented. They have been extracted from real and simulated $e^+e^-$ data and
used to predict inclusive single particle distributions at different machines.


title:
CP Conserving and CP Violating Asymmetries in $e^+e^-\to t\bar
  t\nu_e\bar\nu_e$} at the NLC: Application to Determining the Higgs Width

abstract:
  The polarization asymmetries of $t$, $\bar t$ quarks can be used in the
reaction $e^+e^-\to t\bar t\nu_e\bar\nu_e$ to measure the Higgs width, in the
Standard Model or in its extensions, and to search for non-standard CP
violating phases. As an application of the CPT theorem the Higgs width is
monitored through a CP-even, $T_N$-odd, polarization asymmetry, $B_y$. CP
violation manifests through interference at tree graph level with the resonant
Higgs amplitude. Consequently, the asymmetries are all quite sizable and can be
in the range of 10--50\% for a wide choice of the Higgs mass.


title: CPT, Strings, and Neutral Mesons

abstract:
  A sketch of our results on CPT and strings is given. A mechanism for
spontaneous CPT violation in string theory is briefly reviewed, and recent
theoretical progress is summarized. Possible CPT-violating contributions to a
four-dimensional low-energy effective theory could produce effects at levels
testable in neutral-meson systems. Likely experimental signatures and
attainable bounds are outlined in candidate experiments with correlated and
uncorrelated neutral mesons.


title: CPT, Strings, and Neutral-Meson Systems

abstract:
  This talk provides an overview of a string-based mechanism for spontaneous
CPT violation. A summary is given of theoretical developments. The mechanism
could generate CPT-violating contributions to a four-dimensional low-energy
effective theory and thereby produce detectable consequences for candidate
experiments with neutral-meson systems.


title: QCD from a Large N Perspective

abstract:
  The 1/N expansion of QCD can be used to calculate properties of nucleons and
Delta baryons, such as masses, magnetic moments, and pion couplings. The
predictions of the 1/N expansion are in excellent agreement with the
experimental data. The 1/N expansion also provides an understanding of the
relation between the quark model, the Skyrme model, and QCD. This talk reviews
some of the recent developments.


title:
Quantum effects on $t\to H^{+} b$ in the MSSM: a window to ``virtual''
  supersymmetry?

abstract:
  We analyze the one-loop effects (strong and electroweak) on the
unconventional top quark decay mode $t\rightarrow H^{+} b$ within the MSSM. The
results are presented in the on-shell renormalization scheme with a physically
well motivated definition of $\tan\beta$. The study of this process at the
quantum level is useful to unravel the potential supersymmetric nature of the
charged Higgs emerging from that decay. As compared with the standard mode
$t\rightarrow W^{+} b$, the corrections to $t\rightarrow H^{+} b$ are large,
slowly decoupling and persist at a sizeable level even for all sparticle masses
well above the LEP 200 discovery range. As a matter of fact, the potential size
of the SUSY effects, which amount to corrections of several ten percent, could
counterbalance the standard QCD corrections and even make them to appear with
the ``wrong'' sign. Therefore, if the charged Higgs decay of the top quark is
kinematically allowed -a possibility which is not excluded by the recent
measurements of the branching ratio $BR(t\rightarrow W^{+} b)$ at the Tevatron
- it could be an invaluable laboratory to search for ``virtual'' supersymmetry.
While a first significant test of these effects could possibly be performed at
the upgraded Tevatron, a more precise verification would most likely be carried
out in future experiments at the LHC.


title: Baryon Asymmetry of the Proton Sea at Low $x$

abstract:
  We predict a nonvanishing baryon asymmetry of the proton sea at low $x$. It
is expected to be about $7\%$ and nearly $x$-independent at $x < 0.5 \times
10^{-3}$. The asymmetry arises from the baryon-antibaryon component of the
Pomeron, rather than from the valence quarks of the proton, which are wide
believed carriers of baryon number. Experimental study of $x$-distribution of
the baryon asymmetry of the proton sea can be performed in $ep$ or $\gamma p$
interactions at HERA, where $x\sim 10^{-5}$ are reachable, smaller than at any
of existing or planned proton colliders.


title: Vacuum Instability in Low-Energy Supersymmetry Breaking Models

abstract:
  We show that for the simplest models of gauge mediated supersymmetry
breaking, including all existing models, the true vacuum will not preserve QCD
if it communicates supersymmetry breaking to the visible sector. We show that
the desired supersymmetry breaking color preserving vacuum can nonetheless be
stable cosmologically, but only if certain couplings are sufficiently small. We
also present simple modifications to the sector which communicates
supersymmetry breaking in which the true vacuum is acceptable, suggesting
desirable properties to be sought in dynamical models of supersymmetry
breaking.


title: Supersymmetry and the spontaneous breaking of a U(1) gauge factor

abstract:
  We investigate a supersymmetric theory with an extra U(1) gauge symmetry
surviving down to low energies. The extra U(1) is assumed to originate from an
E$_6$ grand unified theory (GUT). We show that if one assumes universal soft
supersymmetry breaking scalar masses at the GUT scale, and requires the mass of
the additional U(1) gauge boson to satisfy phenomenological bounds, then the
conditions for electroweak symmetry breaking will provide stringent
restrictions on the allowed parameter space of such a theory. We also determine
the masses of standard as well as exotic sfermions and find that it is possible
for the latter to be lighter than the former. An interesting specific
observation is that a light stop is difficult to accommodate with an extra U(1)
gauge symmetry.


title: NLO Corrections to Jet Cross Sections in DIS

abstract:
  Next-to-leading order corrections to jet cross sections in deep inelastic
scattering at HERA are studied. The predicted jet rates allow for a precise
determination of $\alpha_s(\mu_R)$ at HERA over a wide range of $\mu_R$. We
argue, that the ``natural'' renormalization and factorization scale is set by
the average $k_T^B$ of the jets in the Breit frame and suggest to divide the
data in corresponding $<k_T^B>$ intervals. Some implications for the
determination of the gluon density and the associated forward jet production in
the low $x$ regime at HERA are briefly discussed.


title: The role of resonances in rare K decays

abstract:
  The decays $K \to \pi l^{+} l^{-}$, $K \to \pi \gamma \gamma $ and $K \to \pi
\nu {\bar \nu}$ are investigated using the higher order terms of the chiral
perturbation theory. The counterterms induced by strong, weak and
electromagnetic interactions are determined assuming the resonance exchange.
(Talk presented at the Workshop on K-Physics, Orsay, France, 30 May - 4 June,
1996)


title:
Vector meson leptoproduction and nonperturbative gluon fluctuations in
  QCD

abstract:
  We present a nonperturbative QCD calculation of diffractive vector meson
production in virtual photon nucleon scattering at high energy. We use the
nonperturbative model of the stochastic QCD vacuum which yields linear
confinement and makes specific predictions for the dependence of high-energy
scattering cross sections on the hadron size. Using light cone wave functions
of the photon and vector mesons, we calculate electroproduction cross sections
for $\rho$, $\omega$, $\phi$ and $J/\psi$. We emphasize the behavior of
specific observables such as the ratio of longitudinal to transverse production
cross section and the t-dependence of the differential cross section.


title:
Next-to-leading order renormalization of the $\Delta B=2$ operators in
  the static theory

abstract:
  The renormalization, at the next-to-leading order in $\alpha_s$, of the
$\Delta B=2$ operators at the lowest order in the heavy quark expansion, namely
in the static theory, is computed taking into account previously missed
contributions. These operators are relevant for the calculation of the
$B^0$--$\bar B^0$ mixing on the lattice.


title: Analytic and Numerical Study of Preheating Dynamics

abstract:
  We analyze the phenomenon of preheating,i.e. explosive particle production
due to parametric amplification of quantum fluctuations in the unbroken case,
or spinodal instabilities in the broken phase, using the Minkowski space $O(N)$
vector model in the large $N$ limit to study the non-perturbative issues
involved. We give analytic results for weak couplings and times short compared
to the time at which the fluctuations become of the same order as the tree
level,as well as numerical results including the full backreaction.In the case
where the symmetry is unbroken, the analytic results agree spectacularly well
with the numerical ones in their common domain of validity. In the broken
symmetry case, slow roll initial conditions from the unstable minimum at the
origin, give rise to a new and unexpected phenomenon: the dynamical relaxation
of the vacuum energy.That is, particles are abundantly produced at the expense
of the quantum vacuum energy while the zero mode comes back to almost its
initial value.In both cases we obtain analytically and numerically the equation
of state which turns to be written in terms of an effective polytropic index
that interpolates between vacuum and radiation-like domination. We find that
simplified analysis based on harmonic behavior of the zero mode, giving rise to
a Mathieu equation forthe non-zero modes miss important physics. Furthermore,
analysis that do not include the full backreaction do not conserve energy,
resulting in unbound particle production. Our results do not support the recent
claim of symmetry restoration by non-equilibrium fluctuations.Finally estimates
of the reheating temperature are given,as well as a discussion of the
inconsistency of a kinetic approach to thermalization when a non-perturbatively
large number of particles is created.


title: Microphysics of SO(10) Cosmic Strings

abstract:
  We uncover a rich microphysical structure for SO(10) cosmic strings. For the
abelian string the electroweak symmetry is restored around it in a region
depending on the electroweak scale. A rich structure of nonabelian strings is
found. Some of these also restore the electroweak symmetry. We investigate the
zero mode structure of our strings. Whilst there are right handed neutrino zero
modes for the abelian string, they do not survive the electroweak phase
transition. In general the nonabelian strings do not have fermion zero modes.
We consider the generalisation of our results to other theories and consider
cosmological consequences of them.


title:
Test of the chiral structure and FCNC in the quark sector by radiative B
  meson decays

abstract:
  We study the effects of a vector-like SU(2) quark doublet as a fourth
generation. In this model we examine the chiral structure and the FCNC in the
quark sector by using radiative B meson decays in the allowed region for
parameters from $R_b = {\Gamma_{qq}}/{\Gamma_{had.}}$. We compute the ratio $R
= {Br (b \to d \gamma)}/{Br (b \to s \gamma)}$ in the model which realizes a
different chiral structure as well as FCNC. The constraints has been extracted
from the experimental results of B meson decays, the $T_{new}$ parameter of
oblique corrections and $R_b$. Under the natural assumption that the violation
of the $V-A$ structure in the light-quark sector is small, we can determine the
allowed region for most of the mixings parameters and the vector-like quark
masses. We show that there will be significant deviations in $R$ from the SM
prediction due to the FCNC's and the violation of the $V-A$ structure.


title:
Renormalization group analysis of the Higgs boson mass in a
  noncommutative differential geometry

abstract:
  Within one loop approximation, the renormalization group analysis of the
Higgs boson mass is performed with an initial condition induced by
$m_{_H}=\sqrt{2}m_{_W}$ which is presented in the new scheme of our
noncommutative differential geometry for the reconstruction of the standard
model. This initial condition holds at energy derived from $g^2=(5/3)g'^2$ with
the running SU(2)$_{_L}$ and U(1)$_{_Y}$ gauge coupling constants.
$\sin^2\theta_{_W}=3/8$ is obtained under same conditions. However, contrary to
${\rm SU(5)}$ GUT without supersymmetry, the grand unification of coupling
constant is not realized in this scheme. The physical mass of the Higgs boson
considerably depends on the top quark mass $m_{top}$ since the top quark Yukawa
coupling constants gives a large negative contribution to $\beta$ function of
the Higgs quartic coupling constant in wide range. The Higgs boson mass varies
from 153.42GeV to 191.94GeV corresponding to $168{\rm GeV}\leq m_{top}\leq
192{\rm GeV}$. We find $m_{_H}=164.01$GeV for $ m_{top}=175$GeV and
$m_{_H}=171.92$GeV for $ m_{top}=180$GeV.


title: Baryogenesis through R-parity violation

abstract:
  We consider generation of baryon asymmetry of the universe through $R-$parity
violation in a scenario in which out-of-equilibrium condition is satisfied by
making the electroweak phase transition to be first order. We study all the
$R-$parity violating interaction which can generate $(B-L)$ asymmetry which
then converts to baryon asymmetry of the universe. We demonstrate that
CP--violating sfermion deudy all the $R-$parity violating interaction which can
generate $(B-L)$ asymmetry which then converts to baryon asymmetry of the
universe. We demonstrate that CP--violating sfermion decays contribute more
than that of the neutralino decays in the generation of $(B-L)$ asymmetry.


title:
On the Influence of Momentum Conservation upon the Scaling Behaviour of
  Factorial Moments in High Energy Multiparticle Production

abstract:
  The experimental results on the falling down of scaled factorial moments in
azimuthal variable $\phi$ is studied in some detail. It is shown that this
phenomenon may be referred to the influence of transverse momentum
conservation. The existing experimental data from DELPHI, EMU08, NA22 and UA1
are successfully explained. Various methods are proposed to partly eliminate
this influence and rule out the 'falling down' of factorial moments.


title:
QCD Sum-Rule Calculation of the Kinetic Energy and Chromo-Interaction of
  Heavy Quarks Inside Mesons

abstract:
  We present a QCD sum-rule determination of the heavy-quark kinetic energy
inside a heavy meson, $-\lambda_1/2 m_Q$, which is consistent with the
field-theory analog of the virial theorem. We obtain $-\lambda_1\approx
(0.10\pm 0.05)~\mbox{GeV}^2$, significantly smaller than a previous sum-rule
result, but in good agreement with recent determinations from the analysis of
inclusive decays. We also present a new determination of the chromo-magnetic
interaction, yielding $\lambda_2(m_b)=(0.15\pm 0.03)~\mbox{GeV}^2$. This
implies $m_{B^*}^2-m_B^2=(0.60\pm 0.12)~\mbox{GeV}^2$, in good agreement with
experiment. As a by-product of our analysis, we derive the QCD sum rules for
the three form factors describing the meson matrix element of a
velocity-changing current operator containing the gluon field-strength tensor.


title:
A Possible Signal for QGP Formation from the Minimum-Bias Data of
  Relativistic Large Heavy Ion Collisions

abstract:
  It is argued that the experimentally observed strong upward-bending of the
logarithm of factorial moments versus that of phase space partition number in
the higher-dimensional phase space of nucleus-nucleus collisions is due to the
superposition of elementary collision processes in these collisions. A direct
implication of this observation is that, at high enough energy and/or density,
when the produced particles from individual elementary processes are melted
into a unique system the above-mentioned superposition effect will disappear
and the factorial moments will not be strongly upward-bending any more. So, the
disappearance of strong upward-bending of higher-dimensional factorial moments
in heavy ion collision may be taken as a signal for the formation of a unique
system, or QGP, in this collision.


title: Charmed Mesons Fragmentation Functions

abstract:
  Fragmentation functions for heavy-light mesons, like the charmed D, D^*
mesons, are proposed. They rest on next-to-leading QCD Perturbative
Fragmentation Functions for heavy quarks, with the addition of a
non-perturbative term describing phenomenologically the quark --> meson
transition. The cross section for production of large p_T D, D^* mesons at the
Tevatron is evaluated in this framework.


title: An analysis of soft terms in Calabi-Yau compactifications

abstract:
  We perform an analysis of the soft supersymmetry-breaking terms arising in
Calabi-Yau compactifications. The sigma-model contribution and the instanton
correction to the K\"ahler potential are included in the computation. The
existence of off-diagonal moduli and matter metrics gives rise to specific
features as the possibility of having scalars heavier than gauginos or the
presence of tachyons. Although non-universal soft terms is a natural situation,
we point out that there is an interesting limit where universality is achieved.
Finally, we compare these results with those of orbifold compactifications.
Although they are qualitatively similar some features indeed change. For
example, sum rules found in orbifold models which imply that on average the
scalars are lighter than gauginos can be violated in Calabi-Yau manifolds.


title: Precise Nucleosynthesis Limits on Neutrino Masses

abstract:
  A computation of nucleosynthesis bounds on the masses of long-lived Dirac and
Majorana neutrinos is reviewed. In particular an explicit treatment of the
``differential heating'' of the $\nue$ and $\bnue$ ensembles due to the
residual out-of-equilibrium annihilations of decoupled heavy neutrinos is
included. The effect is found to be considerably weaker than recently reported
by Dolgov et al. For example, the bounds for a Dirac tau neutrino are $\mnt <
0.37$ MeV or $\mnt > 25$ MeV (for $\dNu > 1$), whereas the present laboratory
bound is $\mnt < 23.1$ MeV.


title: Quark masses, chiral symmetry, and the U(1) anomaly

abstract:
  I discuss the mass parameters appearing in the gauge theory of the strong
interactions, concentrating on the two flavor case. I show how the effect of
the CP violating parameter $\theta$ is simply interpreted in terms of the state
of the {\ae}ther via an effective potential for meson fields. For degenerate
flavors I show that a first order phase transition is expected at $\theta=\pi.$
I speculate on the implications of this structure for Wilson's lattice
fermions.


title: Diffractive Deep Inelastic Scattering: the hadronic nature of Quarks

abstract:
  In the framework of Anisotropic Chromo Dynamics, a non-perturbative model of
QCD based on magnetic condensation in the vacuum, we develope a picture of the
Pomeron. Within this model we are able to calculate the diffractive
contribution to deep inelastic scattering in the small Bjorken x region,
actually probed at Hera. We calculate the diffractive structure function of the
proton and make the comparison with the experimental data of Zeus and H1
collaborations. Good agreement with the experimental data, both for the
diffractive structure function $F_2^D$ and for the ''structure function'' of
the Pomeron, is achieved.


title:
Probing Lepton-number/flavour-violation in Semileptonic Tau Decays into
  Two Mesons

abstract:
  The evaluation, systematic analysis and numerical study of the semileptonic
$\tau$-lepton decays with two mesons in the final state has been made in the
frame of the standard model extended by right handed neutrinos. In the
analysis, heavy-neutrino nondecoupling effects, finite quark masses, quark and
meson mixings, finite widths of vector mesons, chiral symmetry breakings in
vector-meson--pseudoscalar-meson vertices and effective
Higgs-boson--pseudoscalar-meson couplings have been included. Numerical
estimates reveal that the decays $\tau^-\to e^-\pi^-\pi^+$, $\tau^-\to
e^-K^-K^+$ and $\tau^-\to e^-K^0\bar{K}^0$ have branching ratios of the order
of $10^{-6}$, close to present-day experimental sensitivities.


title: Gauge Cancellation for Electroweak Processes and the Gervais-Neveu Gauge

abstract:
  A graphical method is developed to study the total or partial cancellation of
gauge-dependent (divergence) terms in electroweak theory. The method is used to
work out rules in the Gervais-Neveu gauge, whose triple-gauge vertex contains
three terms rather than the usual six. This and other features of the gauge
lead to an enormous saving of algebraic labor in the actual computations, as
will be illustrated explicitly in the tree process $W^++W^-\to \gamma+\gamma$.


title: $\alpha_s$ with Lattice QCD

abstract:
  The status of determinations of the strong coupling constant based on lattice
QCD is reviewed.


title:
Impact of Hadronic Decays of the Lightest Neutralino on the Reach of the
  CERN LHC

abstract:
  If $R$-parity is not conserved, the lightest supersymmetric particle (LSP)
could decay via lepton number violating or baryon number violating
interactions. The latter case is particularly insidious since it leads to a
reduction of the $\eslt$ as well as leptonic signals for supersymmetry. We
evaluate cross sections for jets plus $\eslt$, 1$\ell$, $2\ell$ (same-sign and
opposite sign) and $3\ell$ event topologies that result from the simultaneous
production of all sparticles at the CERN Large Hadron Collider (LHC), assuming
that the lightest supersymmetric particle $\tz_1$ decays hadronically inside
the detector via $R$-parity violating interactions. We assume that these
interactions do not affect the production rates or decays of other sparticles.
We examine the SUSY reach of the LHC for this ``pessimistic'' scenario, and
show that experiments at the LHC will still be able to search for gluinos and
squarks as heavy as 1 TeV, given just 10 fb$^{-1}$ of integrated luminosity,
even with cuts designed to explore the canonical SUSY framework with a {\it
conserved} $R$-parity.


title: Cosmological Implications of Radiatively Generated Axion Scale

abstract:
  We study cosmological implications of supersymmetric axion models in which
the axion scale is generated radiatively. Such models lead to the so-called
thermal inflation and subsequent reheating should be constrained not to yield a
too large axion energy density at the time of nucleosynthesis. We examine how
plausible it is that this nucleosynthesis constraint is satisfied for both
hadronic and Dine-Fischler-Srednicki-Zhitnitskii type axion models.
Baryogenesis and the possibility for raising up the cosmological upper bound on
the axion scale in thermal inflation scenario are also discussed.


title: Extended NJL Model for light and heavy mesons without q-qbar thresholds

abstract:
  We consider the NJL model as an effective quark theory to describe the
interaction which is responsible for the quark flavor dynamics at intermediate
energies. In addition to the usual ultraviolet cut-off which is necessary since
the model is non-renormalizable, we also introduce an infrared cut-off which
drops off the unknown confinement part of the quark interaction, which is
believed to be less important for the flavor dynamics. The infrared cut-off
eliminates all q-qbar thresholds, which plague the application of the usual NJL
model beyond low-energy pion physics. We apply this two-cut-off prescription to
the extended NJL model with chiral and heavy quark symmetries proposed recently
by us. We find a satisfactoring description even of the heavy mesons with
spin/parity J/P = (0+, 1+). Furthermore, the shape-parameters of the Isgur-Wise
function are studied as a function of the residual heavy meson mass.


title:
Generalized messengers of supersymmetry breaking and the sparticle mass
  spectrum

abstract:
  We investigate the sparticle spectrum in models of gauge-mediated
supersymmetry breaking. In these models, supersymmetry is spontaneously broken
at an energy scale only a few orders of magnitude above the electroweak scale.
The breakdown of supersymmetry is communicated to the standard model particles
and their superpartners by "messenger" fields through their ordinary gauge
interactions. We study the effects of a messenger sector in which the
supersymmetry-violating F-term contributions to messenger scalar masses are
comparable to the supersymmetry-preserving ones. We also argue that it is not
particularly natural to restrict attention to models in which the messenger
fields lie in complete SU(5) GUT multiplets, and we identify a much larger
class of viable models. Remarkably, however, we find that the superpartner mass
parameters in these models are still subject to many significant contraints.


title:
Remarks on the Hadronic Effect in Muon $g-2$: Low Energy Behavior of
  $V^0 $-$\pi^+$ Scattering

abstract:
  The behavior of the $V^0$-$\pi^+$ scattering amplitude (where $V^0 = \rho^0 ,
\omega$ , or $\phi$) in the low pion momentum limit is studied motivated by its
relevance to the theory of muon $g - 2$. Current algebra analysis shows that
its S-wave component must vanish in the chiral limit under general physical
assumptions. We confirm this result with various low energy models of vector
meson. Our result justifies the calculation of the charged pion loop part of
the hadronic light-by-light scattering contribution to muon $ g-2 $ within the
framework of hidden local symmetry model of low energy hadron dynamics.


title: Chiral perturbation theory

abstract:
  After a general introduction to the structure of effective field theories,
the main ingredients of chiral perturbation theory are reviewed. Applications
include the light quark mass ratios and pion-pion scattering to two-loop
accuracy. In the pion-nucleon system, the linear sigma model is contrasted with
chiral perturbation theory. The heavy-nucleon expansion is used to construct
the effective pion-nucleon Lagrangian to third order in the low-energy
expansion, with applications to nucleon Compton scattering.


title:
The Artificial Neural Networks as a tool for analysis of the individual
  Extensive Air Showers data

abstract:
  In that paper we discuss possibilities of using the Artificial Neural Network
technic for the individual Extensive Air Showers data evaluation. It is shown
that the recently developed new computational methods can be used in studies of
EAS registered by very large and complex detector systems. The ANN can be used
to classify showers due to e.g. primary particle mass as well as to find a
particular EAS parameter like e.g. total muon number. The examples of both
kinds of analysis are given and discussed.


title: Quark Confinement due to Random Interactions

abstract:
  On the level of an effective quark theory, we define confinement by the
absence of quark anti-quark thresholds in correlation functions. We then
propose a confining Nambu-Jona-Lasinio-type model. Its four fermion interaction
in the color channel is mediated by a random color matrix. We investigate the
model's phase structure as well as its behavior under extreme conditions, i.e.
high temperature and/or high density. In order to study the interplay of the
proposed mechanism of confinement and asymptotic freedom, we consider an
extended Gross-Neveu model. Quark anti-quark thresholds are proven to be absent
in the scalar correlation function implying that the decay of the scalar meson
into free quarks is avoided. The transition from the low energy to the high
energy perturbative regime is found to be smooth. Perturbation theory provides
a good description of Green's functions at high energies, although there is no
quark liberation.


title:
Gribov's Theorem on Soft Emission and the Reggeon-Reggeon-Gluon Vertex
  at Small Transverse Momentum

abstract:
  In spite of the fact that the Gribov's theorem about the region of
applicability of the soft emission factorization cannot be referred literally
to the case of massless charged particles, it can be used for the calculation
of soft emission amplitudes in such a case also. We demonstrate this for the
gluon production amplitude in the multi-Regge kinematics with small transverse
momentum.


title: Advantages and Disadvantages of Supersymmetry Breaking at Low Energies

abstract:
  The breaking of supersymmetry is usually assumed to occur in a hidden sector.
Two natural candidates for the supersymmetry breaking transmission from the
hidden to the observable sector are gravity and the gauge interactions. Only
the second one allows for supersymmetry breaking at low energies. I show how
the two candidates deal with the flavor and the $\mu$-problem; I also briefly
comment on the doublet-triplet and dark matter problem.


title: SUSY GUTs contributions and model independent extractions of CP phases

abstract:
  We consider the origin of new phases in supersymmetric grand unification
model, and show how significant new contributions arise from the gluino
mediated diagram. We then present a more general model independent analysis of
various modes of B-decays suggested previously for measurement of the CKM
phases and point out what they really measure. It is in principle possible to
separate out all the phases.


title:
Renormalization of $\Delta B=2$ Transitions in the Static Limit Beyond
  Leading Logarithms

abstract:
  The renormalization group evolution of $\Delta B=2$ transition operators is
studied at leading order in heavy quark effective theory and at next-to-leading
order in QCD. We calculate new contributions that were not taken into account
in previous work and obtain the complete result to next-to-leading logarithmic
accuracy. The various scheme and scale dependences and their cancellation in
physical quantities are discussed explicitly.


title: Generic Formula of Soft Scalar Masses in String Models

abstract:
  We derive formula of soft supersymmetry breaking scalar masses from
4-dimensional string models within a more generic framework. We consider
effects of extra gauge symmetry breakings including an anomalous $U(1)$
breaking through flat directions, that is, $D$-term and $F$-term contributions,
particle mixing effects and heavy-light mass mixing effects. Some
phenomenological implications are discussed based on our mass formula.


title: SUSY Contributions to $R_b$ and Top Decay

abstract:
  I report on a systematic analysis of the MSSM parameter space to obtain the
best SUSY solution to the $R_b$ anomaly within the constraint of top quark
decay. Phenomenological implications for top decay and direct stop production
at the Tevatron collider are discussed.


title: QCD Corrections to $b \to s e^+e^-$ Decay

abstract:
  We give a more complete calculation of $b \to s e^+e^- $ decay including
leading log QCD corrections from $m_{top}$ to $M_W$ in addition to corrections
from $M_{W}$ to $m_b$. The differential decay rate is found to be slightly
suppressed for a large invariant mass of the $e^+e^- $ pair; while the
integrated width is slightly enhanced comparing with the results without the
QCD running from $m_{top}$ to $M_W$.


title:
Non-Leptonic Two-Body Weak Decays of Charmed Mesons and CP-Violating
  Asymmetries

abstract:
  The non-leptonic two body decays of D mesons are studied in the framework of
an improved factorization approximation. The final state interaction effects
are taken into account assuming them dominated by nearby resonances. The
agreement with experimental data is quite good. CP-violating asymmetries are
predicted.


title: Color Singlet Strangelets

abstract:
  When considering strangelets at finite temperature it is important to obey
the constraint that any observed state must be color singlet. This constraint
results in an increase in strangelet masses as calculated at fixed entropy per
baryon. We use the color singlet partition function for an MIT bag, derived
using the group theoretical projection method, to calculate strangelet masses.
Mean shell effects are included in a liquid drop model, by using a density of
states obtained from the multiple reflection expansion. Another important
effect of the color singlet restriction, namely many orders of magnitude
suppression of thermal nucleation of quark-gluon plasma in collisions, will
also briefly be described.


title: Theoretical overview on Diboson production

abstract:
  Precise measurements of weak vector bosons self couplings give a hint on the
electroweak symmetry breaking sector. We first stress that present data from
LEP and TEVATRON clearly indicate that weak bosons are self interacting. We
then review the limits on the trilinear and quadrilinear couplings expected at
LEP2, $e^+e^-$ linear colliders and LHC.


title: HERA prospects on Compositeness and New Vector Bosons

abstract:
  The absence of deviations from the Standard Model for the differential cross
section ${d\sigma}/{dQ^2}$ at HERA is used to set limits on electron quark
compositeness scale and on new vector bosons, especially the hadrophilic one
recently introduced as a possible explanation for LEP/SLC and CDF anomalies.


title: Heavy baryon masses

abstract:
  Simple and plausible rules are used to correlate the masses of the
ground-state baryons containing single heavy ($b$ or $c$) quarks. A comparison
with the experimental data shows that the observed mass difference between the
$\Sigma_b$ and the $\Sigma^*_b$ is unexpectedly large. Predictions for the
masses of the yet undiscovered heavy baryons are given.


title: Superlight neutralino as a dark matter particle candidate

abstract:
  We address the question of how light can be the lightest supersymmetric
particle neutralino to be a reliable cold dark matter (CDM) particle candidate.
To this end we have performed a combined analysis of the parameter space of the
Minimal Supersymmetric Standard Model (MSSM) taking into account cosmological
and accelerator constraints including those from the radiative $b\rightarrow
s\gamma$ decay. Appropriate grand unification (GUT) scenarios were considered.
We have found that the relaxation of gaugino mass unification is sufficient to
obtain a phenomenologically and cosmologically viable solution of the MSSM with
the neutralino as light as 3~GeV. We have found good prospects for direct
detection of these superlight CDM neutralinos via elastic scattering off
various nuclei in the forthcoming experiments with low-threshold DM detectors.
In a certain sense, these experiments can probe the gaugino mass unification
giving constraints on the possible GUT scenarios within the MSSM.


title: Domains of Disoriented Chiral Condensate

abstract:
  The probability distribution of neutral pion fraction from independent
domains of disoriented chiral condensate is characterized. The signal for the
condensate is clear for a small number of domains but is greatly reduced for
more than three.


title: Goldstino Couplings to Matter

abstract:
  A nonlinearly realized supersymmetric action describing the invariant
couplings of the Goldstino to matter is constructed. Using the Akulov-Volkov
Lagrangian, any operator can be made part of a supersymmetric invariant action.
Of particular interest are interaction terms which include the product of the
Akulov-Volkov Lagrangian with the ordinary matter Lagrangian as well as the
coupling of the product of the covariant derivative of the Goldstino field to
the matter supersymmetry current. The later is the lowest dimensional operator
linear in the Goldstino field. A Goldstino Goldberger-Treiman relation is
established and shown to be satisfied by the effective action.


title:
Relativistic and Binding Energy Corrections to Direct Photon Production
  In Upsilon Decay

abstract:
  A systematic gauge-invariant method is used to calculate the rate for an
upsilon meson to decay inclusively into a prompt photon. An expansion is made
in the quark relative velocity v, which is a small natural parameter for heavy
quark systems. Inclusion of these O(v^2) corrections tends to increase the
photon rate in the middle z range and to lower it for larger z, a feature
supported by the data.


title: Influence of strongly coupled, hidden scalars on Higgs signals

abstract:
  To investigate the possible effects of a light hidden sector on Higgs boson
detection, we discuss a model of scalar singlets coupled to the Standard Model.
The model effectively makes the Higgs width a free parameter due to additional
invisible decay modes. This width can become arbitrarily large. Theoretical and
experimental bounds on model parameters are presented. It is shown, how
Standard Model predictions change and that in the case of large coupling, Higgs
signals will be diluted. We study, to which extent such a strongly coupled,
hidden sector can be excluded by present and future Higgs search experiments.


title:
The Three Families from $SU(4)_A\otimes SU(3)_C\otimes SU(2)_L\otimes
  U(1)_X$ SM-like Chiral Models

abstract:
  We give a detailed description of the model construction procedures about our
new approach to the family structure of the standard model. SM-like chiral
fermion spectra, largely "derivable" from the gauge anomaly constraints, are
formulated in a $SU(N)\otimes SU(3)\otimes SU(2)\otimes U(1)$ symmetry
framework as an extension of the SM symmetry. The $N=4$ case gives naturally
three families as a result, with $U(1)_Y$ nontrivially embedded into the
$SU(4)_A\otimes U(1)_X$. Such a spectrum has extra vector-like quarks and
leptons. We illustrate how an acceptable symmetry breaking pattern can be
obtained through a relatively simple scalar sector which gives naturally
hierarchical quark mass matrices. Compatibility with various FCNC constraints
and some interesting aspects of the possible phenomenological features are
discussed, from a non-model specific perspective. The question of incorporating
supersymmetry without putting in the Higgses as extra supermultiplet is also
addressed.


title:
$V_{ub}$ from the Hadron Energy Spectrum in Inclusive Semileptonic B
  Decays

abstract:
  A measurement of the hadron energy spectrum in inclusive semileptonic $B$
decays is proposed as a viable method for extracting $|V_{ub}|$. Compared to
the traditional energy spectrum of the charged lepton, the hadron energy
spectrum exhibits kinematical advantages such as a wider energy window and a
larger signal branching fraction. It is emphasized that the hadron energy
spectrum method is most suited for symmetric $B$ factories, such as CLEO. The
hadron energy distribution is calculated in the approach of the Altarelli et
al. model and of the heavy-quark effective field theory. In both methods,
perturbative QCD corrections, the Fermi motion of the $b$-quark in the
$B$-meson, and the recoil momentum of the $B$-meson (stemming from the
$\Upsilon(4S)$ resonance) are taken into account. We have found excellent
agreement between the spectra calculated in both methods, especially in the
relevant kinematical region below the charmed meson threshold. The theoretical
error to $|V_{ub}|$, which is dominated by the uncertainty of the $b$-quark
mass, is estimated to be at the $\pm 12 \%$ level.


title: Deuteron Electromagnetic Form Factors in the Intermediate Energy Region

abstract:
  Based on a Perturbative QCD analysis of the deuteron form factor, a model for
the reduced form factor is suggested. The numerical result is consistent with
the data in the intermediate energy region.


title: Non-factorizable Contribution to $B_K$ of Order $\langle G^3 \rangle$

abstract:
  Within the Chiral Quark Model we have calculated the effect of
non-factorizable $\langle G^3 \rangle$ contribution to the $B_K$ parameter.
When all diagrams are summed, a vanishing result is obtained.


title: Unitarity and Saturation in the Dipole Formulation

abstract:
  This talk reviews briefly some of the main results of the small-x dipole
formulation with regards to unitarity corrections. It illustrates the
correspondence between unitarity and saturation corrections in the dipole
approach and multiple t-channel pomeron exchange in the traditional BFKL view,
and discusses how one can estimate and understand the effects of saturation.


title: Could the MSSM have no CP violation in the CKM matrix?

abstract:
  We show that all CP violation in the MSSM could originate in the
supersymmetry breaking sector rather than the CKM matrix, and discuss the
important consequences for $B$-physics.


title:
Pion Helicity Structure And Its Consequence For The Hard Scattering Form
  Factor

abstract:
  In a study of the elastic pion form factor for large momentum transfers based
on a modified perturbative QCD (PQCD) approach we have included helicity
components that are customarily neglected. Along with the inclusion of
transverse momentum, this gives a large suppression of the form factor from the
prediction of the original hard scattering model based on PQCD in the $Q^{2}$
domain where experimental data are available. We conclude that nonperturbative
contributions will dominate in this region.


title: Comparison of Atmospheric Neutrino Flux Calculations at Low Energies

abstract:
  We compare several different calculations of the atmospheric neutrino flux in
the energy range relevant for contained neutrino interactions, and we identify
the major sources of difference among the calculations. We find nothing that
would affect the predicted ratio of $\nu_e/\nu_\mu$, which is nearly the same
in all calculations. Significant differences in normalization arise primarily
from different treatment of pion production by interactions of protons in the
atmosphere. Different assumptions about the primary spectrum and treatment of
the geomagnetic field are also of some importance.


title: Flavor, Compositeness, and Dynamical Breaking of Supersymmetry

abstract:
  We should be taking advantage of recent gains in our nonperturbative
understanding of supersymmetric gauge theories to find the ``standard'' model
of of dynamical supersymmetry breaking, and possibly of flavor as well. As an
illustration of the possibilities for understanding the flavor hierarchy, I
describe a realistic, renormalizable, supersymmetric model with a compositeness
scale of $\sim 1-3$ TeV for the top quark, the left handed bottom quark, and
the up-type Higgs. The top-Higgs Yukawa coupling is a dynamically generated
strong interaction effect, and is naturally large, while the other Yukawa
couplings are suppressed.


title:
U(1) Axial Symmetry and Correlation Functions in the High Temperature
  Phase of QCD

abstract:
  Simple group-theoretical arguments are used to demonstrated that in the high
temperature (chirally restored) phase of QCD with N massless flavours, all
n-point correlation functions of quark bilinears are invariant under U(1) axial
transformations provided n < N. In particular this implies that the two-point
correlation function in the eta' channel is identical to that in the pion
channel for N > 2. Unlike previous work, this result does not depend on the
topological properties of QCD and can be formulated without explicit reference
to functional integrals.


title: Supersymmetric Inflation With Constraints on Superheavy Neutrino Masses

abstract:
  We consider a supersymmetric model of inflation in which the primordial
density fluctuations are nearly scale invariant (the spectral index n is
approximately 0.98) with amplitude proportional to (M/M_{Planck})^2, where M ~
10^{16} GeV denotes the scale of the gauge symmetry breaking associated with
inflation. The 60 or so e-foldings take place when all relevant scales are
close to M, which helps suppress supergravity corrections. The gravitino and
baryogenesis (via leptogenesis) constraints help determine the two heaviest
right handed neutrino masses to be approximately 2 x 10^{13} GeV and 6 x 10^9
GeV.


title: Dispersive theory of charmonium on the Lattice

abstract:
  Physical contribution of the high-energy part of hadronic spectrum is
incorporated to describe the short-distance part of the correlator of
heavy-quark currents obtained by quenched Monte-Carlo on a $8^3*16$- and
$16^3*32$-lattices for $\beta= \{ 6, 6.3 \}$. The lattice artifacts in the
short-distance behavior of that correlator are isolated. The physical
short-distance part of the correlator is fitted by the relevant expressions of
perturbative QCD, which allows one to obtain the renormalized charmed quark
mass with rather high accuracy $m_c^{\bar{MS}}(m_c)\,=\,1.22(5)\,GeV$.


title: The Glueball; The Fundamental Particle of Non-Perturbative QCD

abstract:
  Theoretical ideas related to the existence of glueballs in QCD are reviewed.
These include non-perturbative phenomena such as confinement, instantons,
vacuum condensates and renormalons. We also discuss glueball dominance of the
trace of the stress-tensor, the mass content of the nucleon and a theorem on
the lightest glueball state.


title: The wedge form of relativistic dynamics

abstract:
  It is commonly accepted that in hadronic or nuclear collisions at extremely
high energies the shortest scales are explored. At the classical level, this
property of the interaction is closely related to the Lorentz contraction of
the fields of colliding particles which provides instantaneous switching the
interaction on. I argue that the underlying quantum dynamics should be confined
to within the light wedge of the two-dimensional plane where the first
interaction takes place and suggest to include this property as the boundary
condition for the quantum field theory which describes the collision process.
Connection between the type of inclusive process and the temporal order of its
dynamical evolution is discussed. The one-particle states and propagators of
the perturbation theory for the scalar and fermion fields are found.


title:
Spurious poles of the axial gauge propagators and dynamics of the
  interacting fields

abstract:
  The origin of the spurious poles of the gauge field propagators in the
temporal axial and the null-plane gauges is discussed. The conclusion is that
these poles do not require any special prescription. They are a manifestation
of the fact that that the gauge field acquires a static configuration.


title: The Wedge Form of relativistic Dynamics. II. The Gluons

abstract:
  I derive expressions for various correlators of the gauge field and find
propagators in a new gauge A^\tau=0. This gauge is a part of the wedge form of
relativistic dynamics suggested earlier as the tool for the study of quantum
dynamics in collisions of hadrons at extremely high energies and in
ultrarelativistic heavy ion collisions. The new gauge puts the quark and gluon
fields of the colliding hadrons in one Hilbert space and thus allows one to
avoid factorization.


title:
Color-Octet Contribution and Direct CP Violation in $B\to \psi (\psi')
  X$

abstract:
  We study $c \bar c$ color-octet contribution to $B\to \psi (\psi') X$. When
this contribution is included, the theoretical predictions for the branching
ratios become in much better agreement with the experiment. This mechanism also
enhances the partial rate asymmetries by about a factor of five. The inclusive
$\psi(\psi')$ resulting from $b\to d+{}$gluon can have asymmetry around a few
percent whereas those from $b\to s+{}$gluon has it around $4\times 10^{-4}$.
The asymmetry in the former modes should be observable, to a significance of
$3\sigma$, with about $(1-10)\times 10^8B$ mesons.


title: Are nontopological strings produced at the electroweak phase transition?

abstract:
  We formulate a local condition for a nontopological defect to be present. We
apply it for electroweak strings and estimate the probability of their
existence at the Ginzburg temperature. As a result we find strings long enough
to serve for baryon-number generation are unlikely to be produced.


title: An R-Parity Breaking SUSY Solution to the R_b and ALEPH Anomalies

abstract:
  We discuss an optimal $R$-parity breaking SUSY solution to the $R_b$ excess
as well as the ALEPH 4-jet anomaly. The latter arises from the pair production
of stop via chargino decay at LEP1.5, followed by its $R$--violating decay into
a light quark pair. The model satisfies top quark and $Z$--boson decay
constraints along with gaugino mass unification.


title:
Nonequilibrium process in the $\sigma$ model and chemical relaxation
  time in a homogeneous pionic gas

abstract:
  In a homogeneous pionic gas system, chemical nonequilibrium process is
considered to understand its effect in the expansion processes that are
realized immediately after heavy ion collisions. The chemical relaxation time
is calculated by incorporating the $\pi+\pi \leftrightarrow \pi+\pi+\pi+\pi$
reaction, which is given in the second order of perturbation in the $\sigma$
model. The $\pi+\pi \leftrightarrow \pi+\pi+\pi+\pi$ reaction is assumed to be
less frequent than the $\pi+\pi \leftrightarrow \pi+\pi$ scattering that is
expected to establish the local equilibrium, and hydrodynamical equation is
solved for various initial conditions. It is shown that the relaxation time is
of the order of 100fm and does not have a significant effect on the expansion
process, which implies that the pion number freezeout takes place at an early
stage of the expansion.


title: Stimulated Neutrino Conversion and Bounds on Neutrino Magnetic Moments

abstract:
  Recent experiment proposed to observe induced radiative neutrino transitions
are confronted to existing bounds on neutrino magnetic moments from earth-based
experiments. These are found to exclude any observation by several orders of
magnitude, unless the magnetic moments are assumed to be strongly momentum
dependent. This possibility is discussed in some generality, and we find that
nontrivial dependence of the neutrino form factor may indeed occur, leading to
quite unexpected effects, although this is insufficient by orders of magnitude
to justify the experiments.


title:
On the Forward Scattering Amplitude of the Virtual Longitudinal Photon
  at Zero Energy

abstract:
  The theorem is proved, determining the forward scatterring amplitude of
virtual longitudinal photon at zero energy on any hadronic target in the limit
of small photon virtualities $Q^2$. The theorem is strict, based only on Lorenz
and gauge invariance. No assumptions about the strong interaction, besides the
gap in the mass spectrum, are used. Two terms in the expansion over $Q^2$ are
calculated. The estimation is given up to what $Q^2$ the elastic term can
represent the whole amplitude of longitudinal virtual photon-proton scattering.


title: Meson photoproduction at threshold in three flavor soliton models

abstract:
  In Skyrme-type models, the leading term of the low-energy photoproduction
amplitude is identical to the standard expression and independent of the number
of flavors considered, but subleading terms are not.


title: Coloron Phenomenology

abstract:
  A flavor-universal extension of the strong interactions was recently proposed
in response to the apparent excess of high-$E_T$ jets in the inclusive jet
spectrum measured at the Tevatron. This paper studies the color octet of
massive gauge bosons (`colorons') that is present in the low-energy spectrum of
the model's Higgs phase. Constraints from searches for new particles decaying
to dijets and from measurements of the weak-interaction $\rho$ parameter imply
that the colorons must have masses greater than 870-1000 GeV. The implications
of recent Tevatron data and the prospective input from future experiments are
also discussed.


title: Nonequilibrium Neutrino Oscillations and Primordial Production of He-4

abstract:
  We studied nonequilibrium oscillations between left-handed electron neutrinos
and nonthermalized sterile neutrinos in medium for resonant and nonresonant
cases. The exact kinetic equations for neutrinos, written in terms of neutrino
density matrix in {\it momentum space} were analyzed. The evolution of neutrino
density matrix was numerically calculated. This allowed to study precisely the
evolution of the neutrino number densities, energy spectrum distortion and the
asymmetry between neutrinos and antineutrinos for each momentum mode. The
influence of nonequilibrium oscillations on the primordial production of He-4
was calculated. Cosmological constraints on the oscillation parameters were
obtained.


title: Hard thermal loops in a magnetic field and the chiral anomaly

abstract:
  The fermionic dispersion relation in the presence of a background magnetic
field and a high temperature QED plasma is calculated exactly in the external
field, using the Hard Thermal Loop effective action. As the field strength
increases there is a smooth transition from the weak-field ($qB\ll q^2T^2$)
thermal dispersion relations to the vacuum Landau levels when the background
field is much stronger than any thermal effects ($qB\gg q^2T^2$). The
self-energy at finite field strength acquires an imaginary part. The spectral
width becomes important for critical field strengths ($qB \sim q^2T^2$),
necessitating the use of the full spectral function. It is shown that the
spectral function satisfies the usual condition of normalization and causality.
Using the exact spectral function I also show that the production of chirality
in an external electromagnetic field at high temperature is unaffected by the
presence of the thermal masses of the fermions.


title: The Electroweak Phase Transition through the Renormalization Group

abstract:
  We study the high-temperature phase transitions for the Abelian and $SU(2)$
Higgs models, using the exact renormalization group. The evolution equation for
a properly-defined coarse-grained free energy is solved. The phase diagram of
the Abelian Higgs model has a region of second-order phase transitions governed
by fixed points, for which we calculate critical exponents and crossover
curves. It also has a region of first-order phase transitions, which we discuss
in terms of the coarse-grained free energy. The $SU(2)$ Higgs model for small
Higgs field masses has only first-order phase transitions. We derive their
properties and compare with lattice and perturbative results. For larger Higgs
field masses the strength of the first-order phase transitions diminishes. For
masses larger than 80-100 GeV we find evidence that they are replaced by
analytical crossovers.


title:
A Global $\chi^2$ Analysis of Electroweak Data (including Fermion Masses
  and Mixing Angles) in SO(10) SUSY GUTs

abstract:
  We present a global $\chi^2$ analysis of electroweak data, including fermion
masses and mixing angles, in SO(10) SUSY GUTs. Just as precision electroweak
data is used to test the Standard Model, the well determined Standard Model
parameters are the precision electroweak data for testing theories beyond the
Standard Model. In this talk we use the latest experimentally measured values
for these parameters. We study several models discussed in the literature. One
of these models provides an excellent fit to the low energy data with $\chi^2
\sim 1$ for 3 degrees of freedom. We present our predictions for a few selected
points in parameter space.


title: Determination of the $Z'$ Mass and Couplings Below Threshold at the NLC

abstract:
  We investigate the capability of the NLC to indirectly determine both the
mass as well as the couplings to leptons and $b$-quarks of a new neutral gauge
boson below direct production threshold. By using data collected at several
different values of the collider center of mass energy, we demonstrate how this
can be done in an anonymous and model-independent manner. The procedure can be
easily extended to the top and charm quark couplings.[To appear in the
Proceedings of the 28th International Conference on High Energy Physics,
Warsaw, Poland, 25-31 July 1996]


title:
Experimental consequences of no-scale supergravity in light of the CDF
  $ee\gamma\gamma$ event

abstract:
  We explore two possible interpretations for the CDF
$ee\gamma\gamma+E_T\hskip-13pt/\quad$ event in the context of a recently
proposed one-parameter no-scale supergravity model with a light gravitino. We
delineate the region in parameter space consistent with the kinematics of the
event interpreted either as selectron pair-production ($p\bar p\to\tilde
e^+\tilde e^-\,X$, $\tilde e=\tilde e_R,\tilde e_L$) or as chargino
pair-production ($p\bar p\to\chi^+_1\chi^-_1\,X$). In the context of this
model, the selectron interpretation requires $\tilde e=\tilde e_R$ and predicts
comparable rates for $\ell^\pm\gamma\gamma+E_T\hskip-13pt/\quad$, whereas the
chargino interpretation predicts comparable rates for
$(\ell^\pm\ell^{'+}\ell^{'-},\ell^+\ell^-,\ell^+\ell^-jj)\,\gamma\gamma
+E_T\hskip-13pt/\quad$. We also consider the constraints from LEP~1.5 and the
expectations for LEP~2. We point out that one of the acoplanar photon pairs
observed by the OPAL collaboration at LEP~1.5 may be attributable to
supersymmetry in the present model via $e^+e^-\to\chi^0_1\chi^0_1\to
\gamma\gamma+E_T\hskip-13pt/\quad$. We also show how similar future events at
LEP~2 may be used to deduce the neutralino mass.


title: Higgs Boson Mass in Models with Gauge-Mediated Supersymmetry Breaking

abstract:
  We present the predictions for the mass $M_h$ of the lightest Higgs boson in
models with gauge-mediated supersymmetry breaking as a function of the
SUSY-breaking scale. We include all radiative corrections up to two loops and
point out that if the CDF e+ e- two-photon event is interpreted in terms of
these models, then the lightest Higgs boson should be lighter than 110 GeV.


title: QCD Sum Rule Analysis for the \Lambda_b to \Lambda_c Semileptonic Decay

abstract:
  The 1/m_c and 1/m_b corrections to the \Lambda_b to \Lambda_c semi- leptonic
decay are analyzed by QCD sum rules. Within the framework of heavy quark
effective theory,the subleading baryonic Isgur-Wise func- tion of \Lambda_b to
\Lambda_c has been calculated. It is shown that the corrections due to the 1/m
Lagrangian insertion are negligibly small. The sizable 1/m_Q effect to the
decay lies only in the weak current. The decay spectrum and the branching ratio
are given.


title: Covariant Solutions of the Bethe-Salpeter Equation

abstract:
  There is a need for covariant solutions of bound state equations in order to
construct realistic QCD based models of mesons and baryons. Furthermore, we
ideally need to know the structure of these bound states in all kinematical
regimes, which makes a direct solution in Minkowski space (without any
3-dimensional reductions) desirable. The Bethe-Salpeter equation (BSE) for
bound states in scalar theories is reformulated and solved for arbitrary
scattering kernels in terms of a generalized spectral representation directly
in Minkowski space (K. Kusaka et al., PRD 51, 7026 '95). This differs from the
conventional Euclidean approach, where the BSE can only be solved in ladder
approximation after a Wick rotation.


title:
Has the Substructure of Quarks Been Found by the Collider Detector at
  Fermilab?

abstract:
  The significant excess recently found by the CDF Collaboration in the
inclusive jet cross section for jet transverse energies $E_T \ge 200$ GeV over
current QCD predictions can be explained either by possible production of
excited bosons (excited gluons, weak bosons, Higgs scalars, etc.) or by that of
excited quarks. The masses of the excited boson and the excited quark are
estimated to be around 1600 GeV and 500 GeV, respectively.


title: Ruling Out a Strongly-Interacting Standard Higgs Model

abstract:
  Previous work has suggested that perturbation theory is unreliable for Higgs-
and Goldstone-boson scattering, at energies above the Higgs mass, for
relatively small values of the Higgs quartic coupling $\lambda(\mu)$. By
performing a summation of nonlogarithmic terms, we show that perturbation
theory is in fact reliable up to relatively large coupling. This eliminates the
possibility of a strongly-interacting standard Higgs model at energies above
the Higgs mass, complementing earlier studies which excluded strong
interactions at energies near the Higgs mass. The summation can be formulated
in terms of an appropriate scale in the running coupling,
$\mu=\sqrt{s}/e\approx\sqrt{s}/2.7$, so it can easily be incorporated in
renormalization-group improved tree-level amplitudes as well as higher-order
calculations.


title: epsilon'/epsilon Computation -- Long-distance Evolution

abstract:
  We present a status report on our study of long-distance contributions to the
decay amplitudes A(K^0 --> pi pi, I) in the framework of the 1/N expansion. We
argue that a modified prescription for the identification of meson momenta in
the chiral loop corrections has to be used to gain a self-consistent picture
which allows an appropriate matching with the short-distance part. Possible
uncertainties in the analysis of the density-density operators Q_6 and Q_8
which dominate the CP violation parameter epsilon'/epsilon are discussed. As a
first result we present the long-distance 1/N correction to the gluon penguin
operator Q_6 in the chiral limit.


title:
The role of the pion cloud in the interpretation of the valence
  light-cone wavefunction of the nucleon

abstract:
  The pion cloud renormalises the light-cone wavefunction of the nucleon which
is measured in hard, exclusive photon-nucleon reactions. We discuss the leading
twist contributions to high-energy exclusive reactions taking into account both
the pion cloud and perturbative QCD physics. The nucleon's electromagnetic
form-factor at high $Q^2$ is proportional to the bare nucleon probability $Z$
and the cross-sections for hard (real at large angle or deeply virtual) Compton
scattering are proportional to $Z^2$. Our present knowledge of the pion-nucleon
system is consistent with $Z = 0.7 \pm 0.2$. If we apply just perturbative QCD
to extract a light-cone wavefunction directly from these hard exclusive
cross-sections, then the light-cone wavefunction that we extract measures the
three valence quarks partially screened by the pion cloud of the nucleon. We
discuss how this pion cloud renormalisation effect might be understood at the
quark level in terms of the (in-)stability of the perturbative Dirac vacuum in
low energy QCD.


title: Binding of Quarks and the pi-N sigma-Term

abstract:
  It is shown that the binding effect that is associated with the short range
part of the Goldstone boson exchange interaction between constituent quarks
provides a good description of the $\pi N$ $\sigma$-term.


title: A New Approach to QCD Sum Rules and Inclusive $\tau$ Decay

abstract:
  We show that renormalization group improvement, making use of analyticity and
the structure of the operator product expansion, combined with a
non-perturbative expansion method allows one to describe quarkonium states via
QCD sum rules without the need for explicit power corrections. This technique
also allows an accurate determination of parameters related to the inclusive
decay of the $\tau$ lepton.


title: Particle Physics for Cosmology

abstract:
  I discuss some central issues in particle physics which are potentially
relevant to cosmology. I first briefly review the present (glorious)
experimental status of the Standard Model, emphasizing that it provides a firm
foundation both for early Universe cosmology and for further exploration toward
the basic laws of Nature. I then provide a critique, arguing that while there
are no clear discrepancies, there are several major, specific deficiencies of
the Standard Model which clearly point up its provisional character. I
elaborate on the story theorists have made up to address one of these problems,
the problem of scattered multiplets, and show how upon following it out one
finds, within existing experiments, encouragement -- bordering on evidence --
for certain ambitious ideas regarding unification and supersymmetry. I briefly
describe and contrast two paradigms of supersymmetry breaking, which have
markedly different experimental and cosmological consequences. I call attention
to specific connections with cosmology where appropriate throughout; and near
the end I make some more global remarks. Finally I venture a speculation
suggesting, in a fairly concrete way, the possibility that the laws of physics
cannot, in principle, be disentangled from cosmology.


title: Defect-Antidefect pair production via field oscillations

abstract:
  We show that the mechanism of vortex-antivortex pair production via field
oscillations, earlier proposed by two of us for systems with first order
transitions in presence of explicit symmetry breaking, is in fact very
generally applicable. We further argue that this mechanism applies to all sorts
of topological defects (e.g. strings, monopoles, textures) and for second order
transitions as well. We also show this explicitly by numerically simulating
production of vortex-antivortex pairs by decay of bubble walls for a U(1)
global theory in the absence of any explicit symmetry breaking.


title: MSW Without Matter

abstract:
  We examine the effects of a scalar field, coupled only to neutrinos, on
oscillations among weak interaction current eigenstates. The existence of a
real scalar field is manifested as effective masses for the neutrino mass
eigenstates, the same for $\nbar$ as for $\n$. Under some conditions, this can
lead to a vanishing of $\delta m^2$, giving rise to MSW-like effects. We
present an idealized example and show that it may be possible to resolve the
apparent discrepancy in spectra required by r-process nucleosynthesis in the
mantles of supernovae and by Solar neutrino solutions.


title:
First Order Quark-Gluon/Hadron Transition May Affect Cosmological
  Nucleosynthesis

abstract:
  In the model of a first order quark-gluon/hadron phase transition in which
the hadronic phase is considered as vacuum bubbles growing in the quark-gluon
background with chiral symmetry broken inside the bubble, we find the estimate
for the length scale associated with inhomogeneities originated during the
transition, $10$ m $\;\stackrel{<}{\sim }\ell \stackrel{<}{\sim }40$ m, being
sufficient to produce significant effects on cosmological nucleosynthesis.


title: Mass Spectrum of a Baryon Octet is Linear

abstract:
  It is argued that the mass spectrum of a baryon octet is linear, consistent
with a Gell-Mann--Okubo type relation for the squared masses of the baryons
obtained previously by Bal\'{a}zs and Nicolescu. The mass spectrum of a baryon
decuplet is briefly discussed.


title: On the Thermodynamics of Chiral Symmetry Restoration

abstract:
  The formulas for the temperature dependences of the non-strange and strange
quark condensates are derived by taking into account the contribution of the
massive resonances. Critical temperature of the chiral symmetry restoration
transition is established to be 190 MeV if only meson resonances are
considered, and 175 MeV if both meson and baryon resonances are taken into
account.


title: On the Thermodynamics of Hot Hadronic Matter

abstract:
  The equation of state of hot hadronic matter is obtained, by taking into
account the contribution of the massive states with the help of the resonance
spectrum $\tau (m)\sim m^3$ justified by the authors in previous papers. This
equation of state is in agreement with that provided by the low-temperature
expansion for the pion intracting gas. It is shown that in this picture the
deconfinement phase transition is absent, in agreement with lattice gauge
calculations which show the only phase transition of chiral symmetry
restoration. The latter is modelled with the help of the restriction of the
number of the effective degrees of freedom in the hadron phase to that of the
microscopic degrees of freedom in the quark-gluon phase, through the
corresponding truncation of the hadronic resonance spectrum, and the decrease
of the effective hadron masses with temperature, predicted by Brown and Rho.
The results are in agreement with lattice gauge data and show a smooth
crossover in the thermodynamic variables in a temperature range $\sim 50$ MeV.


title: On Renormalized Strong-Coupling Quenched QED in Four Dimensions

abstract:
  We study renormalized quenched strong-coupling QED in four dimensions in
arbitrary covariant gauge. Above the critical coupling leading to dynamical
chiral symmetry breaking, we show that there is no finite chiral limit. This
behaviour is found to be independent of the detailed choice of photon-fermion
proper vertex in the Dyson-Schwinger equation formalism, provided that the
vertex is consistent with the Ward-Takahashi identity and multiplicative
renormalizability. We show that the finite solutions previously reported lie in
an unphysical regime of the theory with multiple solutions and ultraviolet
oscillations in the mass functions. This study supports the assertion that in
four dimensions strong coupling QED does not have a continuum limit in the
conventional sense.


title:
Global QCD Analysis, the Gluon Distribution, and High $E_t$ Inclusive
  Jet Data

abstract:
  We report on an extensive global QCD analysis of new DIS and hadronic
inclusive jet production data emphasizing the impact of these recent data on
the determination of the gluon distribution, and on the interpretation of the
high $E_t$ jets highlighted by the CDF collaboration. This analysis results in
(i) a better handle on the range of uncertainty of the gluon distribution, (ii)
a new generation of CTEQ parton distributions which incorporates this
uncertainty, (iii) a viable scenario for accommodating the high $E_t$ jets in
the conventional pQCD framework, and (iv) a systematic study of the sensitivity
of the various hard processes to $\alpha_s$ and the consistency of $\alpha_s$
determination in global analysis.


title:
t anti-t Production Rates at the Tevatron and the LHC in Topcolor-
  Assisted Multiscale Technicolor Models

abstract:
  We study the contributions of the neutral pseudo Goldstone bosons
(technipions and top-pions) to the t anti-t production cross sections at the
Tevatron and the LHC in topcolor-assisted multiscale technicolor (TOPCMTC)
models via the gluon-gluon fusion process from the loop-level couplings between
the pseudo Goldstone bosons and the gluons. The MRS set A' parton distributions
are used in the calculation. It is shown that the new CDF datum on the t anti-t
production cross section gives constraints on the parameters in the TOPCMTC
models. With reasonable values of the parameters in TOPCMTC models, the cross
section at the Tevatron is larger than that predicted by the standard model,
and is consistent with the new CDF data. The enhancement of the cross section
and the resonance peaks at the LHC are more significant, so that it is testable
in future experiments.


title:
Higgs Production and other Two-Photon Processes in eA Collisions at HERA
  Energies

abstract:
  The planed HERA upgrade will increase the integrated luminosity by two orders
of magnitude.A new program of electron-nucleus collisions at HERA is under
discussion now.In this connection we present prospects for the study of a light
neutral Higgs boson, SUSY-particle, hadrons and leptons productionin the
two-photon coherent eA collisions at HERA energies.


title:
Color-Octet Contribution to $J/\psi$ Hadroproduction with Nonzero $p_T$
  at Fixed Target Energies

abstract:
  We calculated the color-octet contribution to the $\ps$ hadroproduction at
fixed target energies $\sqrt(s)\simeq40$ GeV. We consider the $\ps$ production
with transverse momenta which can not be explained by primordial motion of
partons, $p_T>1.5$ GeV. It is shown that color octet contribution is dominant
at these energies and reduces large dicrepancies between experimental data and
color singlet model predictions. Having taken into account both contribution
one needs a K-factor about 2-3 to explain the experimental data.


title: A Form Factor Model for Exclusive B- and D-Decays

abstract:
  An explicit model is presented which gives the momentum transfer-dependent
ratios of form factors of hadronic currents. For the unknown Isgur-Wise
function and its generalization for transitions to light particles a simple
phenomenological Ansatz is added. The model allows a calculation of all form
factors in terms of mass parameters only. It is tested by comparison with
experimental data, QCD sum rules and lattice calculations.


title: Heavy quarkonia

abstract:
  Two complementary approaches to the theory of heavy quarkonia are discussed.
The nonrelativistic potential models give amazingly accurate predictions, but
lack a theoretical justification. The expansion in powers of $v/c$ is
theoretically very acceptable, but is not as good in giving numerical
predictions. The importance of combining these two approaches is stressed.


title:
Dilepton/Photon Production in Heavy Ion Collisions and the QCD Phase
  Transition

abstract:
  We calculate electromagnetic production from highly excited hadronic matter
created in heavy ion collisions. The rates include the usual lowest order
processes in quark-gluon plasma plus the usual reactions in the hadronic phase,
related with rho,a_1 mesons. The space-time integration is done using a
hydrodynamical model. We have found that dilepton mass spectrum agrees with
results of other previous works, but *disagrees* with the CERES dilepton data.
In order to explain these data, some "unconventional" production mechanism need
to be incorporated: we discuss especially the notion of modified rho,a_1
masses, which indeed may explain the data. Other suggestions (e.g. the
longer-lived fireball) to increase the production of low mass dileptons seem to
be insufficient for the task. The results for direct photon production are
below the current WA80 experimental bounds, for all variants considered.


title: Gell-Mann--Okubo Mass Formula for an SU(4) Meson Hexadecuplet

abstract:
  Using a linear mass spectrum of an $SU(4)$ meson hexadecuplet, we derive the
Gell-Mann--Okubo mass formula for the charmed mesons, in good agreement with
experiment. Possible generalization of this method to a higher symmetry group
is briefly discussed.


title: Mass Spectrum of a Meson Nonet is Linear

abstract:
  It is argued that the mass spectrum of a meson nonet is linear, consistent
with the standard Gell-Mann--Okubo mass formula and leading to an extra
Gell-Mann--Okubo mass relation for the masses of the isoscalar states. This
relation is shown to hold with an accuracy of up to $\sim $3\% for all
well-established nonets. It also suggests a new $q\bar{q}$ assignment for the
scalar meson nonet.


title: CP violation through effective lagrangians

abstract:
  A model independent study of non-Standard Model CP-violating processes is
presented with emphasis on the observability of the effects.


title: A Note on the External-Field Method in QCD Sum Rules

abstract:
  The external-field method has been used extensively in the QCD sum-rule
approach to explore various hadron static properties. In the traditional
formalism of this method, the transitions from the ground state hadron to
excited states are not exponentially suppressed relative to the ground state
term and thus contaminate the ground state hadron property to be extracted. In
this paper, we suggest a modified formalism, in which the transition terms are
exponentially suppressed relative to the ground state term. As such, the pole
plus continuum spectral model, traditionally invoked in QCD sum-rule approach,
can be adopted. Thus, this modified formalism has potential to improve the
predictability and reliability of external-field sum-rule calculations, which
is illustrated in an explicit example.


title: Gluon density in nuclei

abstract:
  In this talk we present our detail study ( theory and numbers) [1] on the
shadowing corrections to the gluon structure functions for nuclei. Starting
from rather contraversial information on the nucleon structure function which
is originated by the recent HERA data, we develop the Glauber approach for the
gluon density in a nucleus based on Mueller formula [2] and estimate the value
of the shadowing corrections in this case. Than we calculate the first
corrections to the Glauber approach and show that these corrections are big.
Based on this practical observation we suggest the new evolution equation which
takes into account the shadowing corrections and solve it. We hope to convince
you that the new evolution equation gives a good theoretical tool to treat the
shadowing corrections for the gluons density in a nucleus and, therefore, it is
able to provide the theoretically reliable initial conditions for the time
evolution of the nucleus - nucleus cascade.


title: Virtual Compton Scattering on the Proton at High s and Low t

abstract:
  Virtual Compton Scattering (VCS) at low transferred momenta to the proton
($t$) and sufficiently high c.m. energies ($s$) may be used to a) study
$Q^2$--dependence of leading $t$--channel exchanges and b) look for onset of
scaling behavior with increasing $Q^2$. I discuss the implications for
perturbative and nonperturbative QCD and suggest possible experiments.