title:
Cosmological Relics of the High Energy Cold Dark Matter Particle in the
  Universe

abstract:
  We demonstrate that if the universe is dominated by the massive cold dark
matter, then besides the generally believed thermal distribution of the dark
matter relics, there may exist some very energetic non-thermal relics of the
dark matter particles in the universe from some unknown sources, such as from
decay of supermassive X particle released from topological defect collapse or
annihilation. Very interesting, we point out that these high energy dark matter
particles may be observable in the current and future cosmic ray experiments.


title: Sudakov Form Factors in Leptoproduction of Vector Mesons

abstract:
  It is shown that Sudakov form factors for a colour dipole in a QCD-inspired
model of leptoproduction of vector mesons reduce the value of the cross section
of the process by an order of magnitude. They suppress the large size quark-
antiquark pairs and unequal sharing of energy among the components of the
dipole. Some freedom in the choice of the model parameters is also discussed.


title: The eta(c)-gamma Transition Form Factor

abstract:
  The eta(c)-gamma transition form factor is calculated within a perturbative
approach. It is shown that the Q^2 dependence of the form factor is well
determined in the region where experimental data is expected in the near
future.


title:
Parton Distribution within Virtual Photon and Diffractive
  Photoproduction in DIS

abstract:
  A simple relativistic model is suggested that elucidates qualitatively the
quark-antiquark distribution within virtual photon. The diffractive
hadroproduction in DIS initiated by highly virtual photon $\gamma ^{*}(Q^2)$ is
discussed in more detail. The main result is that the contribution of large
transverse scale $q\bar q$-fluctuations of the photon is just sufficient to
produce the cross section of its hadron-like strong interaction (in particular,
its diffraction into hadrons) of the same $Q^2$-dependence as the total cross
section of $\gamma ^{*}p$-interaction. It is why observed in DIS fraction of
photon diffractive hadroproduction in $\gamma^{*}p$\enspace interaction is
quite large and does not vary with $Q^2$.


title: Local Properties of Local Multiplicity Distributions

abstract:
  Some aspects of applications of bunching parameters are discussed. It is
investigated to what extent Monte-Carlo models, which have been tuned to
reproduce global event-shape variables and single-particle inclusive
distributions, agree with each other.


title: "Soft" Phenomenology

abstract:
  A review of the soft supersymmetry-breaking parameters and the $\mu$ term
arising in superstring models is performed paying special attention to their
phenomenological implications. In particular, the violation of the scalar mass
universality which may lead to dangerous flavor changing neutral current
phenomena and the existence of charge and color breaking minima are discussed.
Finally, quadratically-divergent loop effects by pure supergravity interactions
on soft parameters and the $\mu$ term are also reviewed and applied to
superstring models. They provide several new sources of the $\mu$ term,
naturally of order the weak scale, but also may lead to non--universal soft
terms.


title:
\mu-e conversion in nuclei versus \mu-->e \gamma : an effective field
  theory point of view

abstract:
  Using an effective lagrangian description we analyze possible new physics
contributions to the most relevant muon number violating processes: $\mu \to e
\gamma$ and $\mu$--$e$ conversion in nuclei. We identify a general class of
models in which those processes are generated at one loop level and in which
$\mu$--$e$ conversion is enhanced with respect to $\mu \to e \gamma$ by a large
$\ln(m^2_\mu/\Lambda^2),$ where $\Lambda$ is the scale responsible for the new
physics. For this wide class of models bounds on $\mu$--$e$ conversion
constrain the scale of new physics more stringently than $\mu \to e \gamma$
already at present and, with the expected improvements in $\mu$--$e$ conversion
experiments, will push it upwards by about one order of magnitude more. To
illustrate this general result we give an explicit model containing a doubly
charged scalar and derive new bounds on its couplings to the leptons.


title:
Effective Chiral Meson-Baryon Lagrangian from Path Integral
  Hadronization of a Quark-Diquark Model

abstract:
  The approach of path integral hadronization, applied to a quark-diquark toy
model, is used to derive an effective chiral meson-baryon Lagrangian. In this
approach the Goldberger-Treiman relation, found at the quark-meson level, is
re-established at the composite hadron level. For illu- strations,
electromagnetic low energy characteristics of composite nucleons are estimated.


title: Fermion and Higgs Masses and the AGUT Model

abstract:
  We present two rather differently based predictions for the quark and lepton
spectrum: One provides a rather successful fit to the mass suppressions---the
well known fermion mass hierarchy---interpreted as due to most mass terms
needing to violate approximately conserved quantum numbers corresponding to the
AGUT group $ SMG^3\times U(1)_f$. This is actually, under certain conditions,
the maximal group transforming the known 45 Weyl components of the quark and
leptons into each other. From the fit to the fermion spectrum, we get a picture
of the series of Higgs fields causing the breakdown (presumably at the Planck
scale) of this AGUT to the Standard Model and, thus, providing the small masses
of all quarks and leptons except for the top quark. We separately predict the
top quark mass to be $173 \pm 5$ GeV and the Higgs mass to be $135 \pm 9$ GeV,
from the assumption that there be two degenerate minima in the effective
potential for the Weinberg Salam Higgs field with the second one at the Planck
field strength.


title: Renormalons and Higher-Twist Contributions to Structure Functions

abstract:
  We review the possibility to use the renormalons emerging in the perturbation
series of the twist-2 part of the nonsinglet structure functions FL, F2, F3,
and g1 to make approximate predictions for the magnitude of the appertaining
twist-4 corrections.


title:
Constraints on Heavy Meson Form Factors Derived from QCD Analyticity,
  Unitarity and Heavy Quark Spin Symmetry

abstract:
  Using the analytic properties of two-point functions in QCD, as well as
unitarity, bounds on the B meson form factor F(q^2) can be derived. Heavy quark
spin symmetry, correctly taken into account, is shown to improve these bounds
significantly.


title: The Heavy Hadron Spectrum

abstract:
  I discuss the spectrum of hadrons containing heavy quarks ($b$ or $c$), and
how well the experimental results are matched by theoretical ideas. Useful
insights come from potential models and applications of Heavy Quark Symmetry
and these can be compared with new numerical results from the ab initio methods
of Lattice QCD.


title: Experimental and Cosmological Implications of Light Gauginos

abstract:
  Gauginos may be nearly massless at tree level, with loop corrections giving a
gluino mass of order 100 MeV and a photino mass of order 1 GeV. Relic photinos
can naturally account for the observed dark matter, but their detection is more
difficult than for conventional WIMPs. The lightest gluino-containing baryon
could account for the recently observed ultra-high energy cosmic rays, which
violate the GZK bound. The predicted mass and properties of the gluino-gluino
boundstate agree with those of the eta(1410), a flavor singlet pseudoscalar
meson which has proved difficult to reconcile with QCD predictions. Laboratory
experiments presently exclude only a small portion of the interesting parameter
space, although improvements expected in the next year may lead to complete
exclusion or discovery.


title: On Charge Quantization and Abelian Gauge Horizontal Symmetries

abstract:
  Under the assumption that there exists a local gauge horizontal symmetry
$G_H$ wich allows only for a top quark mass at tree level, we look for the
constraints that charge quatization and the family structure of the standard
model imposes on that symmetry.


title:
Nonperturbative Flow Equations, Low-Energy QCD and the Chiral Phase
  Transition

abstract:
  We review the formalism of the effective average action in quantum field
theory which corresponds to a coarse grained free energy in statistical
mechanics. The associated exact renormalization group equation and possible
nonperturbative approximations for its solution are discussed. This is applied
to QCD where one observes the consecutive emergence of mesonic bound states and
spontaneous chiral symmetry breaking as the coarse graining scale is lowered.
We finally present a study of the chiral phase transition in two flavor QCD. A
precision estimate of the universal critical equation of state for the
three-dimensional O(4) Heisenberg model is presented. We explicitly connect the
O(4) universal behavior near the critical temperature and zero quark mass with
the physics at zero temperature and a realistic pion mass. For realistic quark
masses the pion correlation length near $T_c$ turns out to be smaller than its
zero temperature value.


title:
Methods of Minimization of Calculations in High Energy Physics: 1. A
  Covariant Method of the Calculation of Amplitudes of Processes Involving
  Polarized Dirac Particles

abstract:
  The article deals with a number of the existings variants of direct
calculation of amplitudes of processes with polarized Dirac particles. It is
shown, that all of them are special cases of one and the same mathematical
scheme. The advantages and disadvantages of this scheme are considered. A new
variant of the method of calculation of amplitudes, keeping all the advantages
of this scheme, but free from disadvantages, is proposed. In particular, this
variant is suitable for the evaluation of amplitudes of processes with
interfering diagrams and does not need any additional calculations, that are
necessary in the general case. Expressions for the amplitudes of processes
involving both massive and massless particles are presented. These expressions
make it possible to create in an easy way the computer programs for automatic
calculation of amplitudes. The existing computer programs for calculation of
amplitudes, their limitations and disadvantages are briefly considered.


title:
Methods of Minimization of Calculations in High Energy Physics: 2.
  Minimization of number of vectors in problem

abstract:
  The various ways to reduce number of vectors describing condition of
particles for high energy physics problems are presented. In particular
decomposition of any vector with respect to the basis, consisting of any four
linearly independent vectors, including the orthonormal basis; construction of
orthonormal bases from vectors of a problem; expression of one vector of
problem through other is considered.


title: Semi-inclusive asymmetries with polarized proton beams at HERA

abstract:
  The prospects of semi-inclusive measurements with polarized proton beams at
HERA are discussed. Detailed simulations show that one can disentangle the
valence-quark and sea-quark contribution to the polarized structure function
g_1(x) in the small x-domain, if the equivalent of 1000 pb-1 of data are
collected. It is also shown how semi-inclusive charged- current events can
provide information on the relative importance of the spin contribution of the
anti-s and anti-d sea quarks. Moreover, various methods to determine the
fragmentation functions in this kinematical domain are presented.


title:
Electroweak Baryogenesis and Higgs and Stop Searches at LEP and the
  Tevatron

abstract:
  It has been recently shown that the observed baryon number may originate at
the electroweak phase transition, provided that the Higgs boson and the
lightest stop are sufficiently light. In this work, we perform a detailed
analysis, including all dominant two-loop finite temperature corrections to the
Higgs effective potential, as well as the non-trivial effects proceeding from
the mixing in the stop sector, to define the region of parameter space for
which electroweak baryogenesis can happen. The limits on the stop and Higgs
masses are obtained by taking into account the experimental bounds on these
quantities, as well as those coming from the requirement of avoiding dangerous
color breaking minima. We find for the Higgs mass $m_h \simlt 105$ GeV, while
the stop mass may be close to the present experimental bound and must be
smaller than, or of order of, the top quark mass. These results provide a very
strong motivation for further non-perturbative analysis of the electroweak
phase transition, as well as for the search for Higgs and stop particles at the
LEP and Tevatron colliders.


title: Modeling The Glueball Spectrum By A Closed Bosonic Membrane

abstract:
  We use an analogy between the Yang-Mills theory Hamiltonian and the matrix
model description of the closed bosonic membrane theory to calculate the
spectrum of glueballs in the large $N_c$ limit. Some features of the Yang-Mills
theory vacuum, such as the screening of the topological charge and vacuum
topological susceptibility are discussed. We show that the topological
susceptibility has different properties depending on whether it is calculated
in the weak coupling or strong coupling regimes of the theory. A mechanism of
the formation of the pseudoscalar glueball state within pure Yang-Mills theory
is proposed and studied.


title:
Up-down atmospheric neutrino flux asymmetry predictions for various
  neutrino oscillation scenarios

abstract:
  We compute up-down asymmetries for atmospheric neutrino induced electron and
muon events in the SuperKamiokande detector for the following neutrino
oscillation models: (A) maximally mixed $\nu_{\mu} - \nu_{\tau}$ or $\nu_{\mu}
- \nu_s$, (B) maximally mixed $\nu_{\mu} - \nu_e$, (C) threefold maximal mixing
between $\nu_e, \nu_{\mu}$ and $\nu_{\tau}$, and (D) neutrino oscillations via
Equivalence Principle or Lorentz invariance violation. We emphasise the role of
different momentum cuts.


title:
Neutrino helicity flip by Cerenkov emission and absorption of plasmons
  in supernova

abstract:
  We show that in a supernova core the longitudinal photon (plasmon) has a
space-like dispersion and Cerenkov absorption and emission of such photons is
kinematically allowed. If the neutrino has a non-zero magnetic moment, then
helicity flipping Cerenkov absorption of a plasmon $\nu_L+\gamma\to\nu_R$ is
the most efficient cooling mechanism of the supernova core, and this allows us
to put a restrictive bound on the neutrino magnetic moment
$\mu_{\nu}~<~0.7\times 10^{-13}\mu_B$.


title: Weak radiative hyperon decays, Hara's theorem and the diquark

abstract:
  Weak radiative hyperon decays are discussed in the diquark-level approach. It
is pointed out that in the general diquark formalism one may reproduce the
experimentally suggested pattern of asymmetries, while maintaining Hara's
theorem in the SU(3) limit. At present, however, no detailed quark-based model
of parity-violating diquark-photon coupling exists that would have the
necessary properties.


title: Pre-equilibrium evolution of quark-gluon plasma

abstract:
  We study the production and the evolution of quark-gluon plasma expected to
be formed in ultra relativistic heavy-ion collisions, within the color
flux-tube model. We introduce the gluonic component in the Boltzmann equation,
which we solve in the phase space which is extended to include the SU(3) color
degree of freedom. The color degree of freedom is shown to play a decisive role
in equilibration, and in fixing the temperature of the plasma. We further find
that the soft partons that we study here contribute substantially to the bulk
properties. Finally, the model is shown to provide a detailed picture of how
the quark-gluon plasma evolves and is driven towards a hydrodynamic flow, which
starts occuring around 1 $fm$.


title: Standard Model Parameters from the Multiple Point Principle and Anti-GUT

abstract:
  We put forward a model, or rather a relatively broad class of models, beyond
the Standard Model based on the two main assumptions: MPP) The coupling
constants should be fixed such as to ensure that there be many ``vacuum
states'', i.e. Lorentz invariant states of the fields, with the same energy
density. Anti-GUT) At high energy, above an essential desert of only Standard
Model interactions, there is the bigger gauge group $SMG^3\times U(1)_f$ which
means that each family of quarks and leptons has its own set of gauge bosons
analogous to those in the Standard Model itself, and then there is one extra
abelian gauge boson called $U(1)_f$. In addition we make some further more
phenomenological assumptions. We succeed in fitting order of magnitudewise most
of the (effective) Yukawa couplings observed in the Standard Model as quark and
lepton masses and mixing angles. We have more accurate numbers for the three
fine-structure constants and the top and Higgs masses, as well as some
suggestive understanding of the fine-tuning wonders for the cosmological
constant and the $\Theta$-angles. CP-violation is predicted a bit low, but
order of magnitudewise in agreement with experiment. In summary, we obtain at
least an order of magnitudewise understanding of the Standard Model parameters
within our scheme, except for the mysteriously low weak scale compared to the
Planck scale, with only 4 continuous parameters being fitted, in addition to
our somewhat more discrete choices.


title: Heavy Quark Effective Fields as Operator-valued Distributions

abstract:
  We look at effective fields defined in the heavy-quark effective theory as
operator-valued generalized functions on Minkowski space-time to be averaged
with physically suitable smoothing functions (Gaussians of typical width the
hadronic size) leading to operator-valued distributions in Hilbert space.
One-heavy-quark states are thus represented by normalizable wave packets
displaying a particle-like behaviour at the characteristic hadronic time
${\Lambda}_{QCD}^{-1}$. We examine some consequences relative to the average
kinetic energy of heavy quarks in hadrons to avoid inconsistences within this
formalism.


title: The Kinematics and Dynamics of Flavor Mixing

abstract:
  In view of the observed strong hierarchy of the quark and lepton masses and
of the flavor mixing angles, it is argued that the description of flavor mixing
must take this into account. One particularly interesting way to describe the
flavor mixing, which, however, is not the one used today, emerges, which is
particularly suited for models of quark mass matrices based on flavor
symmetries. We conclude that the unitarity triangle important for B physics
should be close to or identical to a rectangular triangle. CP violation is
maximal in this sense.


title: Polarized Lambda Production at HERA

abstract:
  We study the prospects for HERA with polarized electron and/or proton beams
to determine the functions describing the fragmentation of a longitudinally
polarized parton into a polarized Lambda baryon. We examine both semi-inclusive
deep-inelastic scattering (SIDIS) and photoproduction of Lambda.


title: Nuclear Structure Functions and Cumulative Processes

abstract:
  The authors's point of view, based on QCD, on the nuclear quark structure is
presented. Different models for explaining the EMC--effect are considered. It
is also shown that cumulative production data are very useful for a better
understanding of the EMC--effect and give some evidence in favor of its
multiquark nature.


title:
Collinear Asymptotic Dynamics for Massive Particles. Multi-Channel Regge
  Behaviour

abstract:
  The high-energy behaviour in a multi-channel system is investigated in the
framework of collinear asymptotic dynamics for massive particles. We consider
the most general trilinear coupling of N different scalar fields. We find Regge
behaviour and obtain closed expressions for the Regge trajectories and
couplings. The results are corraborated in the multi-channel Bethe-Salpeter
approach. The scattering processes dominated by single Regge trajectories are
explicitly given.


title: O(\alpha_s^2) Corrections to Top Quark Production at $e^+e^-$ Colliders

abstract:
  In this article we evaluate mass corrections up to $O((m^2/q^2)^6)$ to the
three-loop polarization function induced by an axial-vector current. Special
emphasis is put on the evaluation of the singlet diagram which is absent in the
vector case. As a physical application $O(\alpha_s^2)$ corrections to the
production of top quarks at future $e^+e^-$ colliders is considered. It is
demonstrated that for center of mass energies $\sqrt{s} >~ 500$ GeV the
inclusion of the first seven terms into the cross section leads to a reliable
description.


title: A positivity bound for the longitudinal gluon distribution in a nucleon

abstract:
  The distribution of longitudinal gluons in a nucleon, introduced earlier by
Gorsky and Ioffe, is estimated from below by making use of the positivity of
density matrix and the analogue of the Wandzura-Wilczek relation for the
light-cone distributions of polarized gluons in a transversely polarized
nucleon.


title: Large Lepton Number of the Universe and The Fate of Topological Defects

abstract:
  We show that the monopole problem in Grand Unified Theories as well as the
domain wall problem may be easily solved if the lepton number asymmetry in the
Universe is large enough.


title:
QCD Corrections and Anomalous Couplings in $Z\gamma$ Production at
  Hadron Colliders

abstract:
  The processes $pp/ pbar p \to Z \gamma + X \to \ell^+ \ell^- \gamma + X$
($\ell=e, \mu$) and $pp/ pbarp \to Z \gamma + X \to \bar\nu\nu\gamma + X$ are
calculated to ${\cal O}(\alpha_s)$ for general $ZZ\gamma$ and $Z\gamma\gamma$
couplings. The impact of ${\cal O}(\alpha_s)$ QCD corrections on the
observability of $ZZ\gamma$ and $Z\gamma\gamma$ couplings in $Z\gamma$
production at the Tevatron and the Large Hadron Collider (LHC) is discussed.


title: Neutrino Mass Texture with Large Mixing

abstract:
  We propose a simple texture for the right-handed Majorana mass matrix to give
a large $\nu_\mu-\nu_\tau$ mixing angle and hierarchical left-handed neutrino
mass pattern. Consistently with the Dirac mass texture of the quark sector
realizing the CKM mixing, this naturally explains the recent experimental
results on both the atmospheric neutrino anomaly observed by the
Superkamiokande collaboration and the solar neutrino problem. In this texture
the right-handed Majorana mass of the third generation is of the order of GUT
scale, which is favorable for reproducing the observed bottom-tau mass ratio.


title: Large Lepton Flavor Mixing and E_6-type Unification Models

abstract:
  There are experimental indications of large flavor mixing between $\nu_{\mu
}$ and $\nu_{\tau}$. In the unification models, in which the massless sector
includes extra particles beyond the standard model, there possibly appear the
mixings between quarks (leptons) and the extra particles. When large mixings
occur, lepton flavor mixings can be quite different from quark flavor mixings.
By taking the string inspired $SU(6) \times SU(2)_R$ model with global flavor
symmetries, we obtain the neutrino flavor mixing $\sin \theta_{23} \simeq
\lambda = \sin \theta_C$ around the unification scale. It can be expected that
due to large Yukawa couplings of neutrinos, the renormalization effect
increases $\sin 2 \theta_{23}$ naturally up to $\sim 1$ at the electroweak
scale. Fermion mass spectra and the CKM matrix of quarks obtained in this paper
are also phenomenologically viable.


title:
The Octet of Goldstone-Bosons in the SU(3) Linear sigma Model in the
  QRPA

abstract:
  A symmetry conserving, non-perturbative treatment based on a variational
squeezed vacuum state in conjunction with a well-defined class of RPA
fluctuations is applied to the SU(3) linear-sigma-model. It is shown that the
Goldstone theorem holds exactly both at zero and finite temperature. The
approach represents a systematic procedure which avoids problems of the
Gaussian Functional with the symmetries.


title:
Helicity amplitudes for the small angle lepton pair production in e^+e^-
  or \mu^+ \mu^- collisions

abstract:
  The lepton pair production $e^- e^+ \to e^- e^+ l^- l^+ $ or $\mu^- \mu^+ \to
\mu^- \mu^+ l^- l^+ $ is studied in the dominant cross section region of
scattering angles ${m_j}/{E_j} \stackrel{<}{\sim} \theta_j \ll 1 $. An
analytical expression is found for all 64 helicity amplitudes of these
processes. The accuracy of the obtained formulae is given omitting only terms
of the order of ${m_j^2}/{E_j^2}$, $\theta_j^2$ and $ \theta_j {m_j}/{E_j}$.
The result has a compact form convenient both for analytical and numerical
calculations of various cross sections in this dominating scattering regime.


title:
NLO $Q^2$-evolution of the nucleon's transversity distribution $h_1(x,
  Q^2)$

abstract:
  We present a calculation of the two-loop anomalous dimension for the
transversity distribution $h_1(x,Q^2)$, $\gamma^{h(1)}_n$, in the MS scheme of
the dimensional regularization. Because of the chiral-odd nature, $h_1$ does
not mix with the gluon distributions, and thus our result is the same for the
flavor-singlet and nonsinglet distributions. At small $n$ (moment of $h_1$),
$\gamma^{h(1)}_n$ is significantly larger than $\gamma^{f,g(1)}_n$ (the
anomalous dimension for the nonsinglet $f_1$ and $g_1$), but approaches
$\gamma^{f,g(1)}_n$ very quickly at large $n$, keeping the relation
$\gamma^{h(1)}_n > \gamma^{f,g(1)}_n$. This feature is in parallel to the
relation between the one-loop anomalous dimension for $f_1$ $(g_1)$ and $h_1$.
We also show that this difference in the anomalous dimension between $h_1$ and
$g_1$ leads to a drastic difference in the $Q^2$-evolution of those
distributions in the small $x$ region.


title: Resonant and nonresonant D+ -> K- pi+ l+ nu(l) semileptonic decays

abstract:
  We analyse the semileptonic decay D+ -> K- pi+ l+ nu(l) using an effective
Lagrangian developed previously to describe the decays D -> P l nu(l) and D ->
V l nu(l). Light vector mesons are included in the model which combines the
heavy quark effective Lagrangian and chiral perturbation theory approach. The
nonresonant and resonant contributions are compared. With no new parameters the
model correctly reproduces the measured ratio Gamma(nres)/Gamma(nres + res). We
also present useful nonresonant decay distributions. Finally, a similar model,
but with a modified current which satisfies the soft pion theorems at the
expense of introducing another parameter, is analyzed and the results of the
models are compared.


title:
Polarized beams at HERA : analyzing the chiral structure of contact
  interactions

abstract:
  In the context of HERA with polarized lepton and proton beams, we explore the
sensitivity of the collider to contact interactions. We emphasize that the
measurement of longitudinal spin asymmetries in such a polarized context could
give some crucial informations on the chiral structure of these hypothetical
new interactions.


title:
Lightest Neutral Higgs Pair Production in Photon-photon Collisions in
  the Minimal Supersymmetric Standard Model

abstract:
  The cross sections for the lightest neutral Higgs pair production at the
one-loop level in photon-photon collisions are calculated in the Minimal
Supersymmetric Standard Model(MSSM). We find that the contributions to the
lightest Higgs boson pair production cross sections arising from the genuine
supersymmetric virtual particles dominate over that arising from the virtual
particles in the two-Higgs-doublet model (2HDM) if there are mixing between the
right- and left-handed stops, otherwise, the contributions from ones in the
2HDM are dominant. We present the detailed numerical results of the cross
sections of the process $e^+e^-\to \gamma\gamma \to h_0h_0$ in both
beamstrahlung and laser back scattering photon modes at the Next Linear
Collider (NLC). The cross sections are typically in the range of $10^{-3}fb $
to $10^5 fb$ depending on the choice of the mass of the lightest neutral Higgs
boson, $\tan\beta$ and photon collision modes, especially whether there are
mixing between the stops.


title: Using muons to probe for new physics

abstract:
  Searches for new physics using muons are reviewed. Particular attention is
paid to muon number non-conserving processes, like the decay muon-->e+gamma and
muon-electron conversion in muonic atoms. Also, experimental determinations and
theoretical predictions for the muon anomalous magnetic moment are reviewed.


title:
Gauge- and Renormalization-Group- Invariant Formulation of the
  Higgs-Boson Resonance

abstract:
  A gauge- and renormalization-group- invariant approach implemented by the
pinch technique is formulated for resonant transitions involving the Higgs
boson. The lineshape of the Higgs boson is shown to consist of two distinct and
physically meaningful contributions: a process-independent resonant part and a
process-dependent non-resonant background, which are separately gauge
independent, invariant under the renormalization group, satisfy naive,
tree-level Ward identities, and respect the optical and equivalence theorem
individually. The former process-independent quantity serves as the natural
extension of the concept of the effective charge to the case of the Higgs
scalar, and constitutes a common ingredient of every Born-improved amplitude.
The difference in the phenomenological predictions obtained within our approach
and those found with other methods is briefly discussed.


title: On the leading logarithmic evolution of the off-forward distributions

abstract:
  We have found the analytical solution of the LO-evolution equation for
off-forward distributions which arise in the processes of deeply virtual
Compton scattering or exclusive production of mesons. We present the
predictions for their evolution with an input distribution taken from recent
bag model calculations.


title:
Measuring |V_{td} / V_{ub}| through B -> M \nu \bar\nu
  (M=\pi,K,\rho,K^*) decays

abstract:
  We propose a new method for precise determination of |V_{td} / V_{ub}| from
the ratios of branching ratios BR(B -> \rho \nu \bar \nu ) / BR(B ->\rho l \nu
) and BR(B -> \pi \nu \bar \nu ) / BR(B -> \pi l \nu ). These ratios depend
only on the ratio of the Cabibbo-Kobayashi-Maskawa (CKM) elements |V_{td} /
V_{ub}|$ with little theoretical uncertainty, when very small isospin breaking
effects are neglected. As is well known, |V_{td} / V_{ub}| equals to (\sin
\gamma) / (\sin \beta) for the CKM version of CP-violation within the Standard
Model. We also give in detail analytical and numerical results on the
differential decay width d\Gamma(B -> K^* \nu \bar \nu ) / dq^2 and the ratio
of the differential rates dBR(B -> \rho \nu \bar \nu )/dq^2 / dBR(B -> K^* \nu
\bar \nu )/dq^2 as well as BR(B -> \rho \nu \bar \nu ) / BR(B -> K^* \nu \bar
\nu) and BR(B -> \pi \nu \bar \nu ) / BR(B -> K \nu \bar \nu).


title:
Nonabelian Nature of Asymmetry for the $B_c$ Meson Production in
  Gluon-Photon Interaction

abstract:
  Calculations of cross-sections for the gluon-photon production of $B_c$ and
$B_c^*$ mesons as well as for the production in $ep$-interactions at HERA are
performed in the leading order of perturbative QCD. We show that the nonabelian
structure of QCD leads to an essential forward-backward asymmetry in these
processes.


title: New developments in threshold pion photo- and electroproduction

abstract:
  Photoproduction of neutral and charged pions off nucleons and deuterium has
been precisely calculated in baryon chiral perturbation theory. I review the
predictions with the accurate data that have become available over the last few
years. Some progress in the description of neutral pion electroproduction off
protons is also discussed.


title:
Cosmic Ray Neutrino Annihilation on Relic Neutrinos Revisited: A
  Mechanism for Generating Air Showers above the Greisen-Zatsepin-Kuzmin
  Cut-off

abstract:
  If neutrinos are a significant contributor to the matter density of the
universe, then they should have $\sim$ eV mass and cluster in galactic (super)
cluster halos, and possibly in galactic halos as well. It was noted in the
early 1980's that cosmic ray neutrinos with energy within $\delta
E/E_R=\Gamma_Z/M_Z \sim 3%$ of the peak energy $E_R=4 (eV/m_{\nu})\times
10^{21}$ eV will annihilate on the nonrelativistic relic antineutrinos (and
vice versa) to produce the Z-boson with an enhanced, resonant cross section of
${\cal O}(G_F)\sim 10^{-32}{cm}^2$. The result of the resonant neutrino
annihilation is a hadronic Z-burst 70% of the time, which contains, on average,
thirty photons and 2.7 nucleons with energies near or above the GZK cutoff
energy of $5\times 10^{19}$ eV. These photons and nucleons produced within our
Supergalactic halo may easily propagate to earth and initiate super-GZK air
showers. Here we show that the probability for each neutrino flavor at its
resonant energy to annihilate within the halo of our Supergalactic cluster is
likely within an order of magnitude of 1%, with the exact value depending on
unknown aspects of neutrino mixing and relic neutrino clustering. The absolute
lower bound in a hot Big Bang universe for the probability to annihilate within
a 50 Mpc radius (roughly a nucleon propagation distance) of earth is 0.036%.
  From fragmentation data for Z-decay, we estimate that the nucleons are more
energetic than the photons by a factor $\sim 10$. Several tests of the
hypothesis are indicated.


title: Perturbative Fragmentation of Leptoquark into Heavy Lepto-Quarkonium

abstract:
  The fragmentation function of a scalar leptoquark into possible S-wave bound
states with a heavy anti-quark is calculated to the leading order in
perturbative QCD for the high energy processes at large transverse momenta. The
one-loop equations for the $q^2$-evolution of moments of the fragmentation
function due to the hard gluon emission by the leptoquark are derived. The
integral probabilities of fragmentation are evaluated.


title: The Aharonov-Casher Effect for Particles of Arbitrary Spin

abstract:
  The Aharonov-Casher (AC) effect for quantum motion of a neutral magnetized
particle in the electric field is believed to be a topological effect closely
related to the known Aharonov-Bohm (AB) effect. We study how it depends on the
spin of the particle involved. Duality of the AB and AC effects is demonstrated
to exist only for two extreme spin (and magnetic moment) projections.
  Classical consideration confirms the conclusion. Motion of a classical
magnetized particle with generally oriented magnetic moment in the AC field
appears to be subjected to both forces and torques. Only for two special
orientations of the magnetic moment (same as in the quantum case) the motion is
effectively free and similar to the AB motion of a charged particle. Thus, the
AC effect is not really topological.
  Presence of higher multipoles totally destroys the possible AB-AC duality.


title: The Status of The Standard Model

abstract:
  Talk given at the XVIII International Symposium on Lepton-Photon
Interactions, Hamburg, 1997.
  1. Introduction
  2. Status of the Data
  3. Precision Electroweak Data and the Standard Model
  4. A More General Analysis of Electroweak Data
  5. The Case for Physics beyond the Standard Model
  6. The Search for the Higgs
  7. New Physics at HERA?
  8. Conclusion


title: Electric Polarizabilities of Neutral Baryons in the QCD Sum Rule

abstract:
  We investigate the electric polarizabilities of neutral baryons using the
method of QCD sum rules. The diagrams in the operator product expansion are
taken into account up to dimension 6. We obtain different values of the
polarizabilities among hyperons, the ordering of which is given
$\bar\alpha_n>\bar\alpha_{\Xi^0}>\bar\alpha_{\Lambda}$. The polarizability of
${\Sigma^0}$, $\bar\alpha_{\Sigma^0}$, has possibly a very small value.


title: Chern-Simons number diffusion with hard thermal loops

abstract:
  We construct an extension of the standard Kogut-Susskind lattice model for
classical 3+1 dimensional Yang-Mills theory, in which ``classical particle''
degrees of freedom are added. We argue that this will correctly reproduce the
``hard thermal loop'' effects of hard degrees of freedom, while giving a local
implementation which is numerically tractable. We prove that the extended
system is Hamiltonian and has the same thermodynamics as dimensionally reduced
hot Yang-Mills theory put on a lattice. We present a numerical update algorithm
and study the abelian theory to verify that the classical gauge theory
self-energy is correctly modified. Then we use the extended system to study the
diffusion constant for Chern-Simons number. We verify the Arnold-Son-Yaffe
picture that the diffusion constant is inversely proportional to hard thermal
loop strength. Our numbers correspond to a diffusion constant of Gamma = 29 +-
6 alpha_w^5 T^4 for m_D^2 = 11 g^2 T^2/6.


title: Fermion Vacuum Effects on Soliton Stability

abstract:
  Just as fermion zero modes can alter the degeneracy and quantum numbers of a
soliton, fermion energies can affect the form and stability of a nontopological
soliton. We discuss the kink in a two-dimensional linear sigma model, and show
that, when coupled to fermions, the kink is no longer an extremum of the energy
functional. The kink in this model possesses many similarities to the
electroweak string in the Weinberg-Salam model.


title:
Leading QCD Corrections to Scalar Quark Contributions to Electroweak
  Precision Observables

abstract:
  In the supersymmetric extension of the Standard Model we derive the two-loop
QCD corrections to the scalar quark contributions to the electroweak precision
observables entering via the rho parameter. A very compact expression is
derived for the gluon-exchange contribution. The complete analytic result for
the gluino-exchange contribution is very lengthy; we give expressions for
several limiting cases that were derived from the general result. The two-loop
corrections, generally of the order of 10 to 30% of the one-loop contributions,
canbe very significant. Contrary to the Standard Model case, where the QCD
corrections are negative and screen the one-loop value, the corresponding
corrections in the supersymmetric case are in general positive, therefore
increasing the sensitivity in the search for scalar quarks through their
virtual effects in high-precision electroweak observables.


title:
The search for the Standard Model Higgs boson at present and future
  colliders

abstract:
  I briefly review the Higgs sector in the Standard Model. After summarizing
the properties of the Higgs boson, I will discuss the prospects for discovering
this particle at the present colliders LEP2 and Tevatron and at the next
generation colliders LHC and a high-energy $e^+e^-$ linear collider. The
possibilities of studying the properties of the Higgs particle will be then
summarized. [Contribution to the European Network Workshop "Tests of the
Electroweak Symmetry Breaking}, Ouranoupolis, Greece, May 1997.]


title: QCD Corrections in Supersymmetric Theories

abstract:
  I discuss the effects of QCD radiative corrections in Supersymmetric
theories. After summarizing the SUSY--QCD lagrangian in the Minimal
Supersymmetric extension of the Standard Model, I will discuss the new features
introduced by SUSY, and the main complications compared to standard QCD
corrections. I will then discuss a few examples of QCD calculations in SUSY
theories, for standard processes and for processes involving SUSY particles
including the extended Higgs sector. [Talk given at "QCD 97", Montpellier 3-9
July 1997.]


title: Implications of Generalized Z-Z' Mixing

abstract:
  We discuss experimental implications of extending the gauge structure of the
Standard Model to include an additional U(1) interaction broken at or near the
weak scale. We work with the most general, renormalizable Lagrangian for the
SU(2)\times U(1)\times U(1) sector, with emphasis on the phenomenon of gauge
kinetic mixing between the two U(1) gauge fields, and do not restrict ourselves
to any of the "canonical" Z' models often discussed in the literature.
Low-energy processes and Z-pole precision measurements are specifically
addressed.


title: Constrained Differential Renormalization

abstract:
  We review the method of differential renormalization, paying special
attention to a new constrained version for symmetric theories.


title:
The Associated Production of Weak Bosons and Jets by Multiple Parton
  Interactions

abstract:
  The sources of $W + n$-jet events in hadron collisions are higher-order QCD
processes, but also multiple-parton interactions. A subprocess producing a $W +
k$-jet final state, followed by one producing $l$ jets in the same
nucleon-nucleon interaction, will result in a $W + n$-jet event if $k + l = n$.
In the simplest case a $W + 2$-jet event can be produced by a quark-antiquark
annihilation into $W$ and a 2-jet event occurring in the same proton-antiproton
interaction. We compute that this happens at the 10% level of the higher-order
QCD processes for the type of cuts made by the Tevatron experiments. For jet
$p_T$ values of order $5{\sim}10$ GeV, multiple-parton interactions dominate
higher-order QCD-processes. The emergence of this new source of $W + n$-jet
events towards lower $p_T $ simulates the running of $\alpha_s$; it is
imperative to remove these processes from the event sample in order to extract
information on the strong coupling constant. Also, BFKL studies of low-$p_T$
jet cross sections are held hostage to a detailed understanding of the
multiple-parton interactions. We perform the calculations required to achieve
these goals. A detailed experimental analysis of the data may, for the first
time, determine the effective areas occupied by quarks and gluons in the
nucleon. These are not necessarily identical. We also compute the
multiple-parton contribution to $Z + n$-jet events.


title: The Quantum Gravitationally Induced Stress Tensor

abstract:
  We derive non-perturbative relations between the expectation value of the
invariant element in a homogeneous and isotropic state and the quantum
gravitationally induced pressure and energy density. By exploiting previously
obtained bounds for the maximum possible growth of perturbative corrections to
a locally de Sitter background we show that the two loop result dominates all
higher orders. We also show that the quantum gravitational slowing of inflation
becomes non-perturbatively strong earlier than previously expected.


title: Decays of 1/2^- Baryons in Chiral Effective Theory

abstract:
  We construct an $SU(3)_L \times SU(3)_R$ symmetric chiral effective model
which includes parity pair baryon fields. It is assumed that the positive and
negative parity baryons in the parity pair have opposite chiral transformation
properties each other. Using this model, strong decays of the negative parity
baryons are studied up to the order of one-loop corrections. The results agree
qualitatively with experiment in the $\pi$ and $K$ channels. We examine how the
model parameters are determined from the decay widths and study their physical
meanings. Possibilities to build other models and relations to the correlation
function analysis are discussed.


title: Dispersion Quark Model of Heavy Meson Decays

abstract:
  We discuss applications of the dispersion quark model to exclusive
semileptonic decays of heavy mesons. The transition form factors in this
relativistic formulation of the quark model are given by double spectral
representations through the wave functions of the initial and final mesons both
in the scattering and the decay regions. An important feature of the model is
that the form factors have the correct behavior in accordance with QCD in the
case of meson decays induced by heavy parent quark transition both to heavy and
light daughter quarks. We demonstrate that the dispersion quark model gives
results compatible with the lattice calculations at large $q^2$ and thus
provides reliable form factors in the whole decay region.


title: Enhanced Three-Body Decay of the Charged Higgs Boson

abstract:
  If the charged Higgs boson H+ exists with mh < mt + mb, the conventional
expectation is that it will decay dominantly into c s-bar and tau+ nu-tau.
However, the three-body decay mode H+ --> W+ b b-bar is also present and we
show that it becomes very important in the low tan(beta) region for mh >~ 140
GeV. We explore its phenomenological implications for the charged-Higgs-boson
search in top-quark decay.


title:
How to account for the interference contributions in monte carlo
  simulations

abstract:
  The diagram technique allows one to calculate the correction factors which
can be used in Monte Carlo simulation of some processes. This is equivalent to
the calculation with accounting for all or some part of the interference
contributions. The example is presented for the simplest case of inelastic
deuteron-deuteron interactions.


title:
Spin-dependent Polarizability of Nucleon with Dispersion Relation in the
  Skyrme Model

abstract:
  We calculate the spin-dependent polarizability of the nucleon in the Skyrme
model. The result is compared with that of a heavy baryon chiral perturbation
theory(HBChPT), and is shown to be the same as that of HBChPT up to the
$\Delta$-pole terms in the narrow width limit of the $\Delta$ state and with
the experimental physical constants. The effect of the $\Delta+\pi$ channel is
rather small and is numerically quite similar to that of the $\Delta$ loop in
the HBChPT. The electric and magnetic polarizabilities are recalculated using
the transverse photon and a consistent inclusion of the $\Delta$ width.


title:
Filtering glueball from $q\bar{q}$ production in proton proton or double
  tagged $e^+e^- \to e^+e^-R$ and implications for the spin structure of the
  Pomeron

abstract:
  The production of $J^{PC} = 1^{++},0^{-+}$ and $2^{-+}$ mesons in double
tagged $e^+e^- \to e^+e^-R$ is calculated and found to have the same
polarisation and dynamical characteristics as observed in $pp \to ppR$.
Implications for the spin structure of the Pomeron are considered. Production
of $0^{++},2^{++}$ mesons in these two processes may enable the dynamical
nature of these mesons to be determined.


title: Stop Production at Hadron Colliders

abstract:
  Stop particles are expected to be the lightest squarks in supersymmetric
theories and the search for these particles is an important experimental task.
We therefore present the cross sections for the production processes
$p\bar{p}/pp \to \ste\steb$ and $\stz\stzb$ at Tevatron and LHC energies in
next-to-leading order supersymmetric QCD. The corrections stabilize the
theoretical predictions for the cross sections, and they are positive, thus
raising the cross sections to values above the leading-order predictions. Mixed
$\ste\stzb/\steb\stz$ pairs can only be generated in higher orders at strongly
suppressed rates.


title: Neutrino Oscillations: a source of Goldstone fields

abstract:
  It is proved that true Goldstone bosons develop coherent fields whenever the
associated charges of the matter particles are not conserved in a macroscopic
scale. The sources of the Goldstone fields are the time rates of quantum number
violation. The case of neutrino flavour oscillations is studied with
application to Supernovae. It is shown that if the Lepton numbers break at the
Fermi scale, the neutrino potentials and oscillation patterns change in the
periods of largest neutrino fluxes. In this way, electron anti-neutrino to muon
anti-neutrino oscillations may occur in the first instants of neutrino
emission.


title:
Sum rules in the superpartner spectrum of the minimal supersymmetric
  standard model

abstract:
  Assuming that the string inspired, universal sum rules for soft
supersymmetry-breaking terms, which have been recently found both in a wide
class of four-dimensional superstrings and in supersymmertic gauge-Yukawa
unified gauge models, are satisfied above and at the grand unification scale,
we investigate theirlow energy consequences and derive sum rules in the
superpartner spectrum of the minimal supersymmetric standard model.


title:
Renormalization of the Twist-3 Flavor Singlet Operators in a Covariant
  Gauge

abstract:
  We investigate the nucleon's transverse spin-dependent structure function
g_2(x, Q^2) in the framework of the operator product expansion and the
renormalization group. We construct the complete set of the twist-3 operators
for the flavor singlet channel, and give the relations among them. We develop
an efficient, covariant approach to derive the anomalous dimension matrix of
the twist-3 singlet operators by computing the off-shell Green's functions. As
an application, we investigate the Q^2-evolution of g_2(x, Q^{2}) for the
lowest moment case, and discuss its experimental implication.


title: CP Violation and Strategies for Extracting CKM Phases

abstract:
  The phenomenon of CP violation and strategies for extracting the angles of
the unitarity triangle are reviewed. Special emphasis is given to the B-meson
system, as it plays an outstanding role to test the Standard Model description
of CP violation at future experimental B-physics facilities. Both general
aspects and recent developments are discussed. It is pointed out that combined
branching ratios for $B_{u,d}\to\pi K$ modes, which have been observed recently
by the CLEO collaboration, and untagged $B_s\to K\bar{K}$ decays may allow us
to derive interesting constraints on the CKM angle $\gamma$ and may eventually
lead to a solid determination of this angle.


title: The production model of Ishida et al. and unitarity

abstract:
  The relation between scattering and production amplitudes imposed by
unitarity and analyticity, recently criticised by Ishida et al., is explained.


title: Dressing the Scalar Glueball

abstract:
  The hadronic dressing of the ten lightest scalar mesons, the $q{\bar q}$
nonet and a glueball, is discussed.


title: A New Quark Model Approach to Hyperon Semi-Leptonic Decays

abstract:
  A new analysis of hyperon semi-leptonic decay data is presented, based on
simple and general arguments for an SU(3)-breaking structure of the couplings
involved. The results obtained are compatible with those of earlier
investigations and highlight the uncertainties inherent in extraction of the
V_us Cabibbo-Kobayashi-Maskawa matrix element from such data, and the need for
complete analyses. For F and D, the results can be summarised by the ratio:
F/D=0.57+/-0.01; while as far as the value of V_us is concerned, the only
conclusion to be drawn is that, insofar as SU(3) breaking is still not totally
under control, the value obtained is compatible but not competitive with that
obtained from kaon semi-leptonic decays.


title: Electroweak gauge boson production at gamma-gamma collider

abstract:
  The processes of electroweak gauge boson production in high energy
photon-photon collisions are surveyed.


title: CP Asymmetry in Majorana Neutrino Decays

abstract:
  We study CP asymmetries in lepton-number violating two-body scattering
processes and show how they are related to CP asymmetries in the decays of
intermediate massive Majorana neutrinos. Self-energy corrections, which do not
contribute to CP asymmetries in two-body processes, induce CP violating
couplings of the intermediate Majorana neutrinos to lepton-Higgs states. We
briefly comment on the implications of these results for applications at finite
temperature.


title:
New Observables for Parity Violation in Atoms: Energy Shifts in External
  Electric Fields

abstract:
  We consider hydrogen-like atoms in unstable levels of principal quantum
number n=2, confined to a finite size region in a non-homogeneous electric
field carrying handedness. The interplay between the internal degrees of
freedom of the atoms and the external ones of their c.m. motion can produce
P-odd contributions to the eigenenergies. The nominal order of such shifts is
10^-8 Hz. Typically such energy shifts depend linearly on the small P-violation
parameters delta_i similarequal 10^-12 (i=1,2), essentially the ratios of the
P-violating mixing matrix elements of the 2S and 2P states over the Lamb shift,
with i=1 (i=2) corresponding to the nuclear spin independent (dependent) term.
We show how such energy shifts can be enhanced by a factor of similarequal 10^6
in a resonance like way for special field configurations where a crossing of
unstable levels occurs, leading to P-violating effects proportional to
squareroot{delta_i}. Measurements of such effects can give information
concerning the ``spin crisis'' of the nucleons.


title:
Meson--photon transition form factors and resonance cross-sections in
  e^+ e^- collisions

abstract:
  Meson--photon--photon transition form factors for S-, P-, and D-wave states
are calculated, the meson being treated as a non-relativistic
heavy-quark--antiquark pair. The full dependence on both photon virtualities is
included. Cross-section formulas for charge-conjugation even mesons with J^P =
0^-, 0^+, 1^+, 2^+, and 2^- in electron--positron collisions are presented and
numerical results for LEP energies are given. In particular, we find two-photon
event rates for \chi_{\rc 1}, \eta_{\rc}(2S), and \eta_{\rb}(1S) within reach
of LEP.
  With minor modifications to incorporate SU(3)-flavour breaking we estimate
rates for 18 light mesons as well, based on the observation that their
two-photon decay widths agree remarkably well with measured data. Finally we
point out that e^+ e^- cross sections for 1^+ states do not vanish at low Q^2,
the Landau--Yang suppression factors of the two-photon cross sections being
compensated by the photon propagators.


title:
Massive gluons and quarks and the equation of state obtained from SU(3)
  lattice QCD

abstract:
  We analyze recent results of SU(3) lattice QCD calculations with a
phenomenological parametrization for the quark-gluon plasma equation of state
based on a quasi-particle picture with massive quarks and gluons. At high
temperature we obtain a good fit to the lattice data using perturbative thermal
quark and gluon masses from an improved HTL scheme. At temperatures close to
the confinement phase transition the fitted masses increase above the
perturbative value, and a non-zero (but small) bag constant is required to fit
the lattice data.


title:
Colour Octet Contribution in Exclusive Charmonium Decay into
  Baryon-Antibaryon

abstract:
  It is argued that colour octet contribution in exclusive charmonium decays is
very important even though the same infrared divergence found in P-wave colour
singlet inclusive decay is absent. This comes about because of the suppression
at the level of the wavefunction of P-wave quarkonia. Using the modified hard
scattering approach of Brodsky, Lepage, Botts, Li and Sterman, we use
charmonium decay into baryon-antibaryon pair as an example and show that the
colour singlet contribution alone is clearly insufficient to explain the
experimental decay widths.


title: Can Transversity Be Measured?

abstract:
  I review the ways that have been proposed to measure the quark transversity
distribution in the nucleon. I then explain a proposal, developed by Xuemin
Jin, Jian Tang and myself, to measure transversity through the final state
interaction between two mesons ($\pi\pi$, $K \bar K$, or $\pi K$) produced in
the current fragmentation region in deep inelastic scattering on a transversely
polarized nucleon.


title: Matter Contributions to the Expansion Rate of the Universe

abstract:
  We consider the effect of various particles on the cosmic expansion rate
relative to that of the graviton. Effectively massless fermions, gauge bosons
and conformally coupled scalars make only minuscule contributions due to local
conformal invariance. Minimally coupled scalars can give much stronger
contributions, but they are still sub-dominant to those of gravitons on account
of global conformal invariance. Unless effectively massless scalar particles
with very particular couplings exist, the leading effect on the expansion rate
is furnished solely by the graviton. An upper bound on the mass of such scalar
particles is obtained.


title: WIMP and Axion Dark Matter

abstract:
  There is almost universal agreement among cosmologists that most of the
matter in the Universe is dark, and there are very good reasons to believe that
most of this dark matter must be nonbaryonic. The two leading candidates for
this dark matter are axions and weakly-interacting massive particles (WIMPs),
such as the neutralino in supersymmetric extensions of the standard model. I
discuss the arguments for these two dark-matter candidates and review
techniques for discovery of these dark-matter particles.


title: Connections Between Lattice Gauge Theory and Chiral Perturbation Theory

abstract:
  In this talk, I address the comparison between results from lattice QCD
computations and Chiral Perturbation Theory (ChPT). I briefly discuss how ChPT
can be adapted to the much-used quenched approximation and what it tells us
about the special role of the $\eta'$ in the quenched theory. I then review
lattice results for some quantities (the pion mass, pion scattering lengths and
the $K^+\to\pi^+\pi^0$ matrix element) and what quenched ChPT has to say about
them.


title: Attractive Central Potential in the SU(3) Skyrme Model

abstract:
  The interaction between the hyperon and the nucleon is investigated in the
SU(3) Skyrme model. The static potential, which is expanded in terms of the
modified SU(3) rotation matrices, is obtained for several orientations with the
Atiyah-Manton ansatz. The interaction is calculated for the NN, \LambdaN, and
\SigmaN systems. The medium-range attraction of the central potential between
\Lambda and N is obtained by considering the \Lambda-\Sigma mixing through the
intermediate state.


title:
Recent Developments in String Theory: A Brief Review for Particle
  Physicists

abstract:
  At the present time, string theory (and its generalizations) remain
relatively abstruse subjects to the particle phenomenologist and
experimentalist. Yet, striking developments of the last two years offer hope
that a fundamental non-perturbative formulation of this theory will be found,
and that this formulation will permit us to make contact with supersymmetric
standard-model physics. This article is based on a talk which attempted to
convey the essence of these recent developments in string theory, in a
non-technical manner, to an audience of particle theorists, phenomenologists
and experimentalists.


title:
On the D*D$\pi$ and B*B$\pi$ coupling constants in the effective quark
  model with chiral symmetry

abstract:
  The coupling constants of D*D$\pi$ and B*B$\pi$ strong interactions are
computed in the effective quark model with chiral symmetry incorporating Heavy
quark effective theory (HQET) and Chiral perturbation theory at the quark level
with linear realization of chiral U(3)XU(3) symmetry. We predict g(D*D$\pi$) =
5.2 and g(B*B$\pi$) = 14.3. The corrections of large heavy quark mass expansion
to the constants g(D*D$\pi$) and g(B*B$\pi$) are calculated and make up less
than 1 per cent.


title:
On the $D^+_s \to \pi^+ \pi^+ \pi^-$ - nonresonant decay in the
  effective quark model with chiral symmetry

abstract:
  The partial widths of the decays $D^+_s \to \phi \pi^+$ and $D^+_s \to \pi^+
\pi^+ \pi^-$ - nonresonant are computed within the effective quark model with
chiral symmetry involving Heavy quark effective theory (HQET) and Chiral
perturbation theory at the quark level (CHPT)$_q$ with linear realization of
chiral U(3) x U(3) symmetry. It is shown that for the explanation of the
experimental probability of the $D^+_s \to \pi^+ \pi^+ \pi^-$ - nonresonant
decay one does not need to use unnaturally heavy light current quarks as has
been suggested in Ref.[1]. The life time of the $D^+_s$ - meson $\tau_{D^+_s} =
(0.59\pm 0.19) x 10^(-12) s$ is computed in good agreement with the
experimental one.


title:
Naturalness, Weak Scale Supersymmetry and the Prospect for the
  Observation of Supersymmetry at the Tevatron and at the LHC

abstract:
  Naturalness bounds on weak scale supersymmetry in the context of radiative
breaking of the electro-weak symmetry are analyzed. In the case of minimal
supergravity it is found that for low tan\beta and for low values of fine
tuning Phi, where Phi is defined essentially by the ratio \mu^2/M_Z^2 where \mu
is the Higgs mixing parameter and M_Z is the Z boson mass, the allowed values
of the universal scalar parameter m_0, and the universal gaugino mass m_{1/2}
lie on the surface of an ellipsoid with radii fixed by \Phi leading to tightly
constrained upper bounds \sim \sqrt\Phi.Thus for tan\beta\leq 2(\leq 5) it is
found that the upper limits for the entire set of sparticle masses lie in the
range < 700 GeV (<1.5TeV) for any reasonable range of fine tuning (\Phi\leq
20). However, it is found that there exist regions of the parameter space where
the fine tuning does not tightly constrain m_0 and m_{1/2}. Effects of non-
universalities in the Higgs sector and in the third generation sector on
naturalness bounds are also analyzed and it is found that non-universalities
can significantly affect the upper bounds. It is also found that achieving the
maximum Higgs mass allowed in supergravity unified models requires a high
degree of fine tuning. Thus a heavy sparticle spectrum is indicated if the
Higgs mass exceeds 120 GeV. The prospect for the discovery of supersymmetry at
the Tevatron and at the LHC in view of these results is discussed.


title:
SUSY QCD corrections to W $\gamma$ production in polarized hadronic
  collisions

abstract:
  We present the calculation of the supersymmetric QCD correction to $W \gamma$
production process in polarized proton-antiproton collisions at the TeV energy
region. We find that the correction can reach 1.2% at parton level with
favorable mass values of squarks and gluino, which is comparable with the
virtual correction part of the conventional QCD. The production rates for
different polarized $p \bar{p}$ collisions are also compared.


title: Hard and Soft Colour Singlet Exchange in the Semiclassical Approach

abstract:
  In the present talk diffraction in deep inelastic scattering is discussed in
the framework of the semiclassical approach. The main emphasis is on the
possibility of a consistent semiclassical description of both hard and soft
colour singlet exchange processes. This approach allows the comparison of hard
and soft colour neutralization in diffractive electroproduction of
high-$p_\perp$ jets or heavy quarks.


title: On Mechanism of Charmed c-Quarks Fragmentation in Hadronic Collisions

abstract:
  We propose a modification of the mechanism of charmed quarks fragmentation
into $D$ mesons in hadronic collisions. It is shown that the distinction in
valence quark distributions in the initial $\pi^{\pm}$ and $K^{\pm}$ mesons
leads to different inclusive spectra of $D$ and $D_s$ mesons produced in
$\pi^{\pm}$ and $K^{\pm}$ beams.


title:
Non-universal Soft SUSY Breaking Effects on Dark Matter and on Physics
  at Colliders

abstract:
  Implications of the effects of non-universalities of the soft SUSY breaking
parameters on dark matter and on physics at colliders is discussed.


title:
Implications of the recent CERN LEP data on nonuniversal interactions
  with the precision electroweak tests

abstract:
  We explore the nonuniversal interaction effects in terms of the precision
variables epsilons with the recent LEP data reported by the Electroweak Working
Group. The epsilon variables with the nonuniversal interactions are calculated
and constrained by the experimental ellipses in the $\epsilon_1$--$\epsilon_b$,
$\epsilon_2$--$\epsilon_b$, and $\epsilon_3$--$\epsilon_b$ planes. We find that
the new data enables us to make a stringent test on the correction to $Z \to b
\bar{b}$ vertex. The $\epsilon_b$ variable is sensitive to the $Z b \bar b$
couplings and thus plays a major role to give constraints on the nonuniversal
interaction effects. Upon imposing the new data on $\epsilon_b$, we have the
allowed range of the model parameter $\kappa_L = 0.0063 \pm 0.0030$ at
1-$\sigma$ level with $m_t = 175$ GeV. Along with the minimal contact term, we
predict the new physics scale $\Lambda \sim$ 1.6 TeV. By combining the
experimental results from all planes we obtain the allowed range of $\kappa_L$
: $0.003 < \kappa_L < 0.010$ at 95 % C.L..


title: Primary Inflation

abstract:
  We consider an inflationary universe scenario with multiple stages of
inflation. The primary inflation, which may start at the Planck epoch, is
followed by secondary inflations, which include the cosmological inflation that
causes the primordial density fluctuations of our universe. We point out that
an initial condition for a secondary inflation is naturally realized if the
e-fold number of the primary inflation is sufficiently large.


title: Perturbative QCD at finite temperature and density

abstract:
  This is a comprehensive review on the perturbative hot QCD including the
recent developments. The main body of the review is concentrated upon dealing
with physical quantities like reaction rates.
  Contents: \S1. Introduction, \S2. Perturbative thermal field theory: Feynman
rules, \S3. Reaction-rate formula, \S4. Hard-thermal-loop resummation scheme in
hot QCD, \S5. Effective action, \S6. Hard modes with $|P^2| \leq O (g^2 T^2)$,
\S7. Application to the computation of physical quantities, \S8. Beyond the
hard-thermal-loop resummation scheme, \S9. Conclusions.


title: Form factors and radiative Corrections in Z' Physics

abstract:
  This lecture contains a pedagogical approach to the description of Z' physics
in the formalism of form factors. Usually, only electroweak corrections are
described by form factors, which modify the Weinberg angle and the overall
normalization. It is demonstrated how this formalism can be extended to include
different Born contributions. In the second part of the lecture, QCD and QED
corrections are considered. The development and consequences of the radiative
tail for a Z' search are discussed in detail.


title: Baryons Electromagnetic Mass Splittings in Potential Models

abstract:
  We study electromagnetic mass splittings of charmed baryons. We point out
discrepancies among theoretical predictions in non-relativistic potential
models. None of them seems supported by experimental data. A new calculation is
presented.


title: Is QCD at small x a string theory?

abstract:
  Using the dipole picture describing the $1/N_C$ limit of QCD at small $x$ and
the conformal invariance properties of the BFKL kernel in transverse coordinate
space, we show that the 1->p dipole densities can be expressed in terms of dual
Shapiro-Virasoro amplitudes B_{2p+2} and their generalization including
non-zero conformal spins. We discuss the possibility of an effective closed
string theory of interacting QCD dipoles.


title:
XLOOPS -- A Program Package calculating One- and Two-Loop Feynman
  Diagrams

abstract:
  The aim of XLOOPS is to calculate one-particle irreducible Feynman diagrams
with one or two closed loops for arbitrary processes in the Standard model of
particles and related theories. Up to now this aim is realized for all one-loop
diagrams with at most three external lines and for two-loop diagrams with two
external lines.


title: Exploring inconsistencies with the Cabibbo-Kobayashi-Maskawa model

abstract:
  A small upper-bound is obtained for the CP phase $\delta$ in a CKM matrix,
$|\sin\delta| \le 0.44$ based on CP independent data on $|V_{ub}/V_{cb}|$
alone. Potential inconsistencies with the CKM model in existing data which need
a theory beyond the standard model to overcome emerge in the analysis using
this CKM matrix. In addition, all CP asymmetry measurables for the $B_d- \bar
B_d$ system are expressed solely by the CP phases in the decay amplitudes.
Remarkably the CP asymmetry of the bench mark process $B_d\to \psi K_S$ equals
sin$2\delta$. This will soon be measured by BaBar and Belle to confront the
above upper-bound.


title:
Electroweak Radiative Effects in Deep Inelastic Interaction of Polarized
  Leptons and Nucleons

abstract:
  The results for one-loop correction to deep inelastic scattering of
longitudinal polarized leptons on longitudinal polarized hadrons are obtained
withing the framework of the standard theory of electroweak interactions and
ordinary quark-parton model. The on-shell renormalization scheme in
t'Hooft-Feynman gauge is applied.
  The numerical analysis is carried out under conditions of modern particle
physics experiments.Particular emphasis is laid on contributions usually
ignored at RC procedure --- electroweak corrections to electromagnetic
asymmetry and RC to hadronic current. The structure of RC contribution to
polarized asymmetries within the framework of QED and electroweak theory is
also discused


title: On Non Perturbative Corrections to the Potential for Heavy Quarks

abstract:
  We discuss non perturbative corrections to the Coulomb-like potential of
heavy quarks at short distances. We consider both the standard framework
provided by infrared renormalons and the assumption that confinement does not
allow weak fields to penetrate the vacuum. In the former case the leading
correction at short distances turns out to be quadratic in r for static quarks.
In the latter case we find a potential which is proportional to r as r
rightarrow 0. We point out that similar effects arise due to a new kind of non
perturbative correction proportional to 1/Q^2, which is unaccounted for by the
operator product expansion and which was recently discussed within a different
framework.
  Phenomenological implications of the linear correction to the potential are
briefly reviewed.


title: Inclusive J/psi production in Upsilon decay via color-octet mechanisms

abstract:
  Calculations for inclusive J/psi production in Upsilon decay through the
color-octet mechanisms b\bar b[^3S_1, 1] -> c \bar c[^{2s+1}L_J, 8] + g are
presented. It is shown that these O(alpha^5_sv^4_c) contributions compete with
other color-octet mechanisms considered in the literature. A critical numerical
analysis of the color-octet contributions to Upsilon -> J/psi + X shows that
further work in this channel, both theoretical and experimental, is necessary
in order to clearly understand the significance of the color-octet component of
the c \bar c component inside the J/psi system.


title:
Consistency constraints on m_s from QCD dispersion relations and chiral
  perturbation theory in K_{l3} decays

abstract:
  We use both old and new theoretical developments in QCD dispersion relation
constraints on the scalar form factor in the decay K --> \pi l \nu_l to obtain
constraints on the strange quark mass. The perturbative QCD side of the
calculation incorporates up to four-loop corrections, while the hadronic side
uses a recently developed parameterization constructed explicitly to satisfy
the dispersive constraints. Using chiral perturbation theory (\chiPT) as a
model for soon-to-be measured data, we find a series of lower bounds on m_s
increasing with the accuracy to which one believes \chiPT to represent the full
QCD result.


title:
Probing small-x parton densities in proton- proton (-nucleus) collisions
  in the very forward direction

abstract:
  We present calculations of several pp scattering cross sections with
potential applications at the LHC. Significantly large rates for momentum
fraction, x, as low as 10^-7 are obtained, allowing for possible extraction of
quark and gluon densities in the proton and nuclei down to these small x values
provided a detector with good acceptance at maximal rapidities is used.


title:
Gallium Solar Neutrino Experiments: Absorption Cross sections, Neutrino
  spectra, and Predicted Event Rates

abstract:
  Neutrino absorption cross sections for 71Ga are calculated for all solar
neutrino sources with standard energy spectra, and for laboratory sources of
51Cr and 37Ar; the calculations include, where appropriate, the thermal energy
of fusing solar ions and use improved nuclear and atomic data. The ratio, R, of
measured (in GALLEX and SAGE) to calculated 51Cr capture rate is R = 0.95 +/-
0.07 (exp)} + ^{+0.04}_{-0.03} (theory). Cross sections are also calculated for
specific neutrino energies chosen so that a spline fit determines accurately
the event rates in a gallium detector even if new physics changes the energy
spectrum of solar neutrinos. Theoretical uncertainties are estimated for cross
sections at specific energies and for standard neutrino energy spectra.
Standard energy spectra are presented for pp and CNO neutrino sources in the
appendices. Neutrino fluxes predicted by standard solar models, corrected for
diffusion, have been in the range 120 SNU to 141 SNU since 1968.


title: Group-Theoretic Evidence for SO(10) Grand Unification

abstract:
  The hypercharges of the fermions are not uniquely determined in SO(10) grand
unification, but rather depend upon which linear combination of the two U(1)
subgroups of SO(10) > SU(3) X SU(2) X U(1) X U(1) remains unbroken. We show
that, in general, a given hypercharge assignment can be obtained only with very
high-dimensional Higgs representations. The observation that the standard model
is obtained with low-dimensional Higgs representations can therefore be
regarded as further evidence for SO(10) grand unification. This evidence is
independent of the fact that SO(10) > SU(5).


title: Large Coulomb corrections in high-energy photon splitting

abstract:
  The Coulomb corrections to the helicity amplitudes of high-energy photon
splitting are examined. The consideration is based on the amplitudes obtained
exactly in the parameter Z\alpha within the quasiclassical approach valid for
small angles between all photon momenta. We consider the case when the
transverse momenta of both final photons are much larger than the electron
mass. It is shown that at Z\alpha \sim 1 the Coulomb corrections essentially
change the result for the cross section as compared to the Born approximation.
The effect of screening is also taken into account.


title: Fast simulation of a HERA--like detector

abstract:
  A set of FORTRAN routines to perform a fast simulation of a HERA--like
detector including the smearing of the $z$ coordinate of the interaction
vertex, the simulation of a tracker system, of an electromagnetic and of a
hadronic calorimeter is presented.


title:
Higher Dimensional Operators in Top Condensation from a Renormalization
  Group Point of View

abstract:
  The predictive power of top-condensation models strongly depends on the
behaviour of higher dimensional operators. These are analyzed in this paper by
an extension of the standard renormalization group (RG) arguments which turns
out to be a surprisingly powerful tool. Top-condensation models intermediated
by underlying scalar exchange can be shown to be mere reparametrizations of the
standard model. Further on, RG-arguments show that dynamical vector states
cannot be lowered in top-condensation models. Finally we give a general
argument concerning the size of higher dimensional operators of heavy vector
exchange.


title: Estimates for non-leading distribution functions

abstract:
  Estimates for leading and non-leading `twist' distribution functions are
obtained within the framework of a diquark spectator model using a non-local
operator representation.


title: One-loop weak dipole moments of heavy fermions in the MSSM

abstract:
  The MSSM predictions at the one-loop level for the weak dipole moments of the
\tau lepton and the b quark are presented. The imaginary part of the AWMDM is
of the order of the SM contribution whereas the real part may be a factor 5
(20) larger for the \tau (b) in the high \tan\beta scenario, still a factor
five below the QCD contribution in the b case. More interestingly, a
contribution up to twelve orders of magnitude larger than in the SM may be
obtained, already at the one-loop level, for the WEDM in a MSSM with complex
parameters.


title: Intrinsic transverse momentum in hard processes

abstract:
  In this contribution I discuss transverse momentum dependent quark
distributions and their operator structure. Some of the experimental
signatures, in particular in Drell-Yan scattering, are given.


title: Vector Meson Production at a Polarized HERA Collider

abstract:
  A successful interpretation of the cross sections for elastic and inelastic
vector meson production can be made if one assumes the underlying dynamics to
be governed by hard partonic subprocesses. Extending these partonic approaches
to longitudinally polarized electron-proton collisions, we estimate the
expected production asymmetries at the HERA collider. The anticipated
statistical errors on these asymmetries mostly turn out to be larger than the
asymmetries themselves, such that an experimental observation of these
asymmetries at HERA looks not feasible.


title:
The gamma* gamma* Total Cross Section and the BFKL Pomeron at the 500
  GeV e+e- Collider

abstract:
  We present a numerical estimate of the $\gamma^* \gamma^*$ total cross
section at the designed 500 GeV $e^+e^-$ Linear Collider, based upon the BFKL
Pomeron. We find that the event rate is substantial provided electrons
scattered under small angles can be detected, and a measurement of this cross
section provides an excellent test of the BFKL Pomeron.


title: QCD Corrections to the Polarized Drell-Yan Process

abstract:
  The results of a recent calculation of the QCD corrections to the
longitudinally polarized Drell-Yan process are summarized. In addition to the
parity conserving double spin asymmetry which is already accessible in the
Drell-Yan production of lepton pairs at fixed target energies, we consider
parity violating single spin asymmetries appearing only in the production of
massive vector bosons at polarized hadron colliders. The prospects for
extracting polarized quark distributions from asymmetries in vector boson
production at RHIC are briefly discussed.


title: Hadron Spectroscopy from the Lattice

abstract:
  Lattice QCD determinations appropriate to hadron spectroscopy are reviewed
with emphasis on the glueball and hybrid meson states in the quenched
approximation. Hybrids are discussed for heavy and for light quarks. The
effects of sea quarks (unquenching) are explored. Heavy-light systems are
presented - particularly excited B mesons.


title: Anomalous dimensions of four-quark operators in the large N_f limit

abstract:
  The anomalous dimensions of four-quark operators $(\bar q_i q_j)_{V-A} (\bar
q_k q_l)_{V-A}$ are calculated in the large $N_f$ limit. As expected, the
result is a convergent series without renormalon ambiguities. Using the
approximation of "Naive Nonabelianization", an additional all-order
contribution to the anomalous dimension matrix is obtained which is somewhat
larger than the exact NLO correction itself. Possible phenomenological
applications in nonleptonic B decays and $B^0 - \bar B^0$ mixing are briefly
considered.


title: Relativistic quark model approach to weak hadronic decays of B mesons

abstract:
  The energetic exclusive two-body nonleptonic decays of B mesons are
investigated in the framework of the relativistic quark model within the
factorization approximation.


title: Quark fragmentation into vector and pseudoscalar mesons at LEP

abstract:
  Some data on the ratio of vector to vector + pseudoscalar mesons, V/(V+P),
and the probability of helicity zero vector states, rho_00, are now available
from LEP. A possible relation between these two quantities and their
interpretation in terms of polarized fragmentation functions are discussed;
numerical estimates are given for the relative occupancies of K and K*, D and
D*, B and B* states.


title: Two-photon physics with GALUGA 2.0

abstract:
  An extended version of the Monte Carlo program GALUGA is presented for the
computation of two-photon production in $\e^+\e^-$ collisions. Functions
implemented for the five $\gamma^\star\gamma^\star$ structure functions now
include several ans\"atze of the total hadronic cross section based on the
BFKL--Pomeron and various Regge-like models. In addition, structure functions
for resonance formation are included with full dependence on the two photon
virtualities $Q_1^2$ and $Q_2^2$ as given in the constituent-quark model. The
six lowest-lying resonances of each of the C-even mesons with $J^{P}= 0^-$,
$0^+$, $1^+$, $2^+$ and $2^-$ are provided. The program can also be used to
calculate with exact kinematics the effective two-photon luminosity function.
Special emphasis is put on a numerically stable evaluation of all variables
over the full $Q_i^2$ range while keeping all dependences on the electron mass
and $Q_i^2$.


title: Hadronization in Particle Physics

abstract:
  The method of path integral hadronization is applied to a local quark-diquark
toy model in order to derive an effective chiral meson-baryon Lagrangian.
Further generalizations to models including both scalar and axial-vector
diquarks as well as nonlocal interactions are discussed.


title:
QCD Corrections to Double and Single Spin Asymmetries in Vector Boson
  Production at Polarized Hadron Colliders

abstract:
  The production of $W^{\pm}$ and $Z^0$ bosons in collisions of longitudinally
polarized protons allows to access various combinations of the polarized quark
distributions from the study of double and single spin asymmetries. We compute
the ${\cal O}(\alpha_s)$ corrections to these asymmetries as function of the
vector boson rapidity $y$ in the hadron-hadron centre-of-mass frame. Detailed
studies of the numerical impact of the next-to-leading order corrections are
presented. The theoretical uncertainties of an extraction of polarized quark
distributions from future vector boson production data are investigated in
detail.


title:
Non-spectator contribution: A mechanism for inclusive B-> X_s eta' and
  exclusive B-> K(*) eta' decays

abstract:
  We propose a mechanism which can explain the large BR(B-> X_s eta')~ 10^(-3)
observed by CLEO. In this mechanism, eta' is produced by the fusion of two
gluons, one from QCD penguin b->sg and the other one emitted by the light quark
inside the B meson. The inclusive decay rate which is calculated via using the
factorization assumption, can easily account for the observed branching ratio.
We also estimate the exclusive branching ratio BR(B->K eta')=7.0X10^(-5) which
is in good agreement with the experimental data and present our prediction for
K* mode BR(B->K* eta')=3.4X10^(-5).


title:
Coupled Channel Analysis of S-Wave Pion-Pion and Kaon-Kaon
  Photoproduction

abstract:
  We present a coupled channel partial wave analysis of nondiffractive S-wave
pi+ pi- and K+ K- photoproduction focusing on the KK threshold. Final state
interactions are included. We calculate total cross sections, angular and
effective mass distributions in both pion-pion and kaon-antikaon channels. Our
results indicate that these processes are experimentally measurable and
valuable information on the f0(980) resonance structure can be obtained.


title: Bosonization in Particle Physics

abstract:
  Path integral techniques in collective fields are shown to be a useful
analytical tool to reformulate a field theory defined in terms of microscopic
quark (gluon) degrees of freedom as an effective theory of collective boson
(meson) fields. For illustrations, the path integral bosonization approach is
applied to derive a (non)linear sigma model from a Nambu-Jona-Lasinio (NJL)
quark model. The method can be extended to include higher order derivative
terms in meson fields or heavy-quark symmetries. It is also approximately
applicable to QCD.


title: Probing penguin coefficients with the lifetime ratio tau(B_s)/tau(B_d)

abstract:
  We calculate penguin contributions to the lifetime splitting between the B_s
and the B_d meson. In the Standard Model the penguin effects are found to be
opposite in sign, but of similar magnitude as the contributions of the
current-current operators, despite of the smallness of the penguin
coefficients. We predict
  tau(B_s)/tau(B_d) -1 = ( -1.2 +/- 10.0 ) * 10^(-3) * (f_{B_s}/190 MeV)^2
where the error stems from hadronic uncertainties. Since penguin coefficients
are sensitive to new physics and poorly tested experimentally, we analyze the
possibility to extract them from a future precision measurement of
tau(B_s)/tau(B_d). Anticipating progress in the determination of the hadronic
parameters epsilon_1, epsilon_2 and f_{B_s}/f_{B_d} we find that the
coefficient C_4 can be extracted with an uncertainty of order |Delta C_4|= 0.1
from the double ratio (tau(B_s)-tau(B_d))/(tau(B^+)-tau(B_d)), if
|epsilon_1-epsilon_2| is not too small.


title:
Corrections to Moments of the Photon Spectrum in the Inclusive Decay B
  \to X_s \gamma

abstract:
  We investigate the two main uncertainties on the extraction of the
nonperturbative matrix elements $\bar{\Lambda}$ and $\lambda_1$ from moments of
the inclusive rare FCNC decay $B \to X_s \gamma$. The first one is due to
unknown matrix elements of higher dimensional operators which are estimated by
varying the matrix elements in a range as suggested by dimensional analysis.
The effect of these terms is found to be small. A second uncertainty arises
from a cut on the photon energy and we give model independent bounds on these
uncertainties as well as their estimates from a simplified version of the ACCMM
model.


title: The box anomaly and radiative decays of \eta(\eta')-mesons

abstract:
  We report on a confined quark model calculation of the transition form
factors for the radiative decays of \eta(\eta')->\gamma l^+l^- and
\eta(\eta')->\gamma\pi^+\pi^-. The \eta-\eta' mixing angle \theta_P is
determined from the set of data on the electromagnetic \eta(\eta') decays. It
is found that \theta_P\sim -16.5. The analysis of the dipionic mass
distribution in the decay \eta'->\gamma\pi^+\pi^- confirms the existence of a
non-resonant contribution which is the box anomaly.


title:
Non-factorizable long distance contributions in color suppressed decays
  of B mesons

abstract:
  $\bar B \to D\pi$, $D^*\pi$, $J/\psi\bar K$ and $J/\psi\pi$ decays are
studied. Their amplitude is given by a sum of factorized and non-factorizable
ones. The latter which is estimated by using a hard pion approximation is
rather small in color favored $\bar B \to D\pi$ and $D^*\pi$ decays but still
can efficiently interfere with the main amplitude given by the factorization.
In the color suppressed $\bar B \to J/\psi\bar K$ and $J/\psi\pi$ decays, the
non-factorizable contribution is very important. The sum of the factorized and
non-factorizable amplitudes can reproduce well the existing experimental data
on the branching ratios for the color favored $\bar B \to D\pi$ and $D^*\pi$
and the color suppressed $\bar B \to J/\psi \bar K$ and $J/\psi\pi$ decays by
taking reasonable values of unknown parameters involved.


title:
Large Lepton Mixing in a Coset-space Family Unification on $E_7/SU(5)
  \times U(1)^3$

abstract:
  We study a coset-space unification model for families based on $E_7/SU(5)
\times U(1)^3$. We find that qualitative structure of quark and lepton mass
matrices in this model describes very well the observation. We stress, in
particular, that the large mixing angle, $\sin^22\theta_{\nu_\mu\nu_\tau}
\simeq 1$, required for the atmospheric neutrino oscillation reported by the
SuperKamiokande collaboration, is naturally obtained, which is a consequence of
unparallel family structure in the present coset-space unification.


title:
Analytical investigation for multiplicity difference correlators under
  QGP phase transition

abstract:
  It is suggested that the study of multiplicity difference correlators between
two well-separated bins in high-energy heavy-ion collisions can be used as a
means to detect evidence of a quark-hadron phase transition. Analytical
expressions for the scaled factorial moments of multiplicity difference
distribution are obtained in a kinetical region ${\bar s}\le 0.3$ within
Ginzburg-Landau description. It is shown that the scaling behaviors between the
moments are still valid, though the behaviors of the moments with respect to
the bin size are completely different from the so-called intermittency
patterns. A universal exponent $\gamma$ is given to describe the dynamical
fluctuations in the phase transition.


title: The Drell-Hearn-Gerasimov Sum-Rule at Polarized HERA

abstract:
  We discuss the potential of polarized HERA to measure the spin dependent part
of the total photoproduction cross-section at large $\sqrt{s_{\gamma p}}$.


title: Production of neutralinos in superstring-inspired E_6 models

abstract:
  We study the neutralino mass spectra and production cross sections at an
e^+e^- linear collider in superstring-inspired E_6 models. These models are
characterized by the existence of new neutral gauge bosons and singlet Higgs
fields which also lead to an extended neutralino sector compared to the Minimal
Supersymmetric Standard Model (MSSM) or the Next-To-Minimal Supersymmetric
Standard Model (NMSSM). For different E_6 models we develop scenarios with new
light exotic neutralinos which may offer important possibilities to distinguish
between the models.


title: Supersymmetric SU(5) model with large supersymmetry breaking scale

abstract:
  Taking into account uncertainties related with the initial coupling constants
and threshold corrections at low and high scales we find that in standard
supersymmetric SU(5) model the supersymmetry breaking scale could be up to
$10^8$ GeV. In the extensions of the standard supersymmetric SU(5) model the
supersymmetry breaking scale could be up to $O(10^{12})$ GeV.
  In standard SU(5) supersymmetric model it is possible to increase the GUT
scale up to $5 \cdot 10^{17}$ GeV provided that the masses of chiral
superoctets and supertriplets are $m_{3,8} \sim O(10^{13})$ GeV. For SU(5)
supersymmetric model with $10^6$ GeV $\leq M_{SUSY} \leq 10^8$ GeV the Higgs
boson mass is predicted to be 120 GeV $\leq m_h \leq $ 150 GeV.


title: Non-factorizable photonic corrections to ee->WW->4fermions

abstract:
  We study the non-factorizable corrections to W-pair-mediated four-fermion
production in ee annihilation in double-pole approximation. We show how these
corrections can be combined with the known corrections to the production and
the decay of on-shell W-boson pairs, and how the full off-shell Coulomb
singularity is included. Moreover, we find that the actual form of the real
non-factorizable corrections depends on the parametrization of phase space,
more precisely, on the definition of the invariant masses of the resonant W
bosons. For the usual parametrization the full analytical results for the
non-factorizable corrections are presented. Our analytical and numerical
results for the non-factorizable corrections agree with a recent calculation,
which was found to differ from a previous one. The detailed numerical
discussion covers the invariant-mass distribution, various angular
distributions, and the lepton-energy distribution for leptonic final states.


title:
Dynamical Cosmological Constant and Relations Among Pseudo Goldstone
  Bosons

abstract:
  The present apparent cosmological constant is interpreted as the potential of
the lightest pseudo Goldstone boson. Some numerical relations among
cosmological parameters and particle masses are shown to arise from the mixture
of this very light particle, whose interaction is of the gravitational order,
with other pseudo Goldstone bosons like the pion and the axion which feel the
strong interaction.


title:
Exclusive Nonleptonic Decays of Heavy Baryons in a Relativistic Quark
  Model

abstract:
  Exclusive nonleptonic decays of bottom and charm baryons are studied within a
relativistic quark model. We include factorizing as well as nonfactorizing
contributions to the decay amplitudes.


title: Weak Decays of Heavy Baryons in the Covariant Quasipotential Approach

abstract:
  Bethe-Salpeter approach has been applied to the study of b --> c transitions
both for heavy mesons and heavy baryons. Meson and baryon IW functions are
calculated on the equal footing. A reasonable agreement with the experimental
data for heavy to heavy semileptonic transitions has been obtained.


title: Single spin asymmetries in the Drell-Yan process

abstract:
  We discuss single transverse spin asymmetries in the Drell-Yan process
originating from so-called gluonic poles in twist-three hadronic matrix
elements, as first considered by Qiu and Sterman. Even though time-reversal
invariance is not broken, the effects of such poles cannot be distinguished
from those of time-reversal odd distribution functions. We show the connection
between gluonic poles and large distance gluon fields, in particular we focus
on boundary conditions. We identify the possible single spin asymmetries in the
Drell-Yan process.


title:
Two-Stage Inflation as a Solution of the Initial Condition Problem of
  Hybrid Inflation

abstract:
  We address the issue of fine-tuning of the initial field configuration that
can lead to hybrid inflation in the context of global supersymmetry. This
problem is generated by the difference between the energy scale at which the
Universe emerges from the Planck era and the inflationary scale implied by the
COBE observations: V^{1/4} \sim 10^{-3} m_{Pl}. We propose a scenario with two
stages of inflation. The first stage, with a typical scale not far from m_{Pl},
occurs ``naturally'' and provides the necessary homogeneity for the second
stage. The latter generates the density perturbations that result in the cosmic
microwave background anisotropy observed by COBE.


title: Hadronic Production of Heavy Quarks

abstract:
  We review the status of theoretical evaluations of heavy quark and heavy
quarkonium hadroproduction cross sections and their comparisons with
experimental data.


title: Heavy hexaquarks in a chiral constituent quark model

abstract:
  We discuss the stability of hexaquark systems of type uuddsQ (Q=c or b)
within a chiral constituent quark model which successfully describes the baryon
spectra including the charmed ones. We find these systems highly unstable
against strong decays and give a comparison with some of the previous
literature.


title: On Chemical Equilibrium in Nuclear Collisions

abstract:
  The data on average hadron multiplicities in central A+A collisions measured
at CERN SPS are analysed with the ideal hadron gas model. It is shown that the
full chemical equilibrium version of the model fails to describe the
experimental results. The agreement of the data with the off-equilibrium
version allowing for partial strangeness saturation is significantly better.
The freeze-out temperature of about 180 MeV seems to be independent of the
system size (from S+S to Pb+Pb) and in agreement with that extracted in e+e-,
pp and p{\bar p} collisions. The strangeness suppression is discussed at both
hadron and valence quark level. It is found that the hadronic strangeness
saturation factor gamma_S increases from about 0.45 for pp interactions to
about 0.7 for central A+A collisions with no significant change from S+S to
Pb+Pb collisions. The quark strangeness suppression factor lambda_S is found to
be about 0.2 for elementary collisions and about 0.4 for heavy ion collisions
independently of collision energy and type of colliding system


title:
Recent progress on the $h^{q,\bar q}_1(x,Q^2)$ Distributions and the
  Nucleon Tensor Charges

abstract:
  We recall the definitions and the basic properties of the transversity
distributions $h^{q,\bar q}_1(x,Q^2)$ and the corresponding nucleon tensor
charges $\delta q(Q^2)$. We briefly comment on different estimates from several
phenomenological models and on the future possible measurements with the
polarized $pp$ collider at RHIC-BNL. Recent works on the $Q^2$-evolution of
$h^{q,\bar q}_1(x,Q^2)$ are also discussed and their implications on a very
useful positivity bound.


title: General Issues in Small-x and Diffractive Physics

abstract:
  A selected review of topics at the border of hard and soft physics is given.
Particular emphasis is a placed on diffraction dissociation at Fermilab and
HERA. Recently, significant differences between diffraction dissociation at
HERA and at Fermilab have become apparent. This may suggest that one already is
reaching nonlinear (unitarity) effects which are extending from the soft
physics region into the semihard regime of QCD.


title: J/Psi Suppression Revisited

abstract:
  The production of J/Psi's in nuclei is re-examined and the critical role of
Feynman x distributions in the study of photoproduction and hadronic production
of both J/Psi's and Drell-Yan dimuons is expatiated. The need to consider both
initial and final state interactions and the key effect of initial state
interactions on the total J/Psi cross section are demonstrated.
  We use a Woods-Saxon Monte Carlo simulation to obtain distributions of the
numbers of collisions prior and subsequent to the charmonium production. With
those results we relate the mean number of nucleon-nucleon collisions, $<n>$ to
$A^{1/3} + B^{1/3}$, and give a new analytic functional form for the A
dependence of the suppression.
  Finally we carry out a full Monte Carlo calculation of S, including an
initial state prior energy loss in keeping with the measured Feynman x
distributions in $\pi$-A and p-A interactions. We use an energy loss
parameterization which is consistent with the energy loss from minimum bias
data fitted in ISAJET. We also use an open charm absorption cross section,
$\sigma_{oc}$, constrained from photoproduction of J/Psi's, to analyze the
latest data on the J/Psi suppression. The role of color screening, the time
evolution of off-shell charmonium to the on-shell J/Psi, and the energy
dependence of the charmonium-nucleon inelastic and absorption cross sections
are discussed. We find no anomalous suppression when comparing our results to
published data.


title:
TeV and Superheavy Mass-Scale Particles from Supersymmetric Topological
  Defects, the Extragalactic Gamma-ray Background, and the Highest Energy
  Cosmic Rays

abstract:
  Cosmic topological defects in a wide class of supersymmetric theories can
simultaneously be sources of higgs particles of mass comparable to the
supersymmetry breaking scale $\sim$ TeV, as well as superheavy gauge bosons of
mass $\sim\eta$, where $\eta$ (>> 1 TeV) denotes the associated gauge symmetry
breaking scale. For cosmic strings with $\eta\sim 10^{14}$ GeV, the higgs decay
can account for the extragalactic diffuse gamma ray background above $\sim$ 10
GeV, while the gauge boson decay may explain the highest energy cosmic ray flux
above $\sim 10^{11}$ GeV, provided that particle production is the dominant
energy loss mechanism for cosmic strings, as recent simulations suggest. By the
same token, cosmic strings with $\eta$ much above $\sim 10^{14}$ GeV will be
ruled out.