title: Status of low energy supersymmetry

abstract:
  We review: 1) constraints on low energy supersymmetry from the search for
Higgs boson and from precision data, 2) dependence of coupling unification on
the superpartner spectrum, 3) naturalness and fine tuning in the minimal and
non-minimal scenarios.


title: Ultra High Energy Cosmic Rays and Inflation

abstract:
  Two processes of matter creation after inflation: 1) gravitational creation
of superheavy (quasi)stable particles, and 2) non-thermal phase transitions
leading to formation of topological defects, may be relevant to the resolution
of the puzzle of cosmic rays observed with energies beyond GZK cut-off. Both
possibilities are reviewed in this talk.


title:
Hard exclusive pseudoscalar meson electroproduction and spin structure
  of a nucleon

abstract:
  The amplitude for hard exclusive pseudoscalar meson electroproduction off
nucleon (nuclear) targets is computed in QCD within the leading $\alpha_s \ln
{Q^2/\lambda_{QCD}^{2}}$ approximation. We show that the distribution of recoil
nucleons depends strongly on the angle between the momentum of the recoil
nucleon and the polarization vector of the target (or outgoing nucleon). This
dependence is especially sensitive to the spin flip skewed parton distribution
(SPD) $\widetilde E$. We argue also that the scaling for this spin asymmetry
sets in at lower Q^2 than that for the absolute cross section. Basing on the
chiral quark-soliton model of the nucleon we estimate quantitatively the spin
asymmetry. In the case of pi+ production this asymmetry is dominated at small t
by the contribution of the pion pole in the isovector SPD $\widetilde E$ as
required by PCAC. In the case of K0 production off a proton we find a large
enhancement of the cross section as compared to the case of pi0 production. For
the forward production of neutral pseudoscalar mesons off a deuteron target we
find the cross section should be zero for the zero deuteron helicity (along the
$\gamma^*D$ direction). We consider also cross sections of quasielastic
processes off nuclei including the feasibility to implant K+,rho-mesons into
nuclear volume.


title: Determination of Alpha_s(1 GeV) from the charmonium fine structure

abstract:
  The strong coupling constant $\alpha_s(\mu)$ is extracted from the fits to
charmonium spectrum and fine structure splittings. The relativistic kinematics
is taken into account and relativistic corrections are shown to increase the
matrix elements defining spin effects up to 40%. The value of $\alpha_s(\mu)$
at low-energy scale $\mu=1.0 \pm 0.2 GeV$ was found to be $\alpha_s(\mu) = 0.38
\pm 0.03 (exp.) + 0.04 (theor.)$ which is about 50% lower than standard
perturbative two-loop approximation and is in good agreement with the freezing
$\alpha_s$ behaviour.


title: g-coupling (g_B*Bpi,g_D*Dpi); A quark model with Dirac equation

abstract:
  We discuss the strong coupling of heavy mesons to a pion g, in the heavy
quark limit. This quantity is quite remarkable since its values as estimated by
different methods (various quark models and the QCD sum rules), are
surprisingly different. The present quark models are mostly based on free
spinors and their predictions depend crucially on the choice of the light quark
mass. We propose a quark model based on the Dirac equation in a central
potential, which gives a more refined description of Dirac spinors. We show
that within such a Dirac model, the value of g is stable and large: g = 0.6(1),
where we assume no quark current renormalization ((g_A)q = 1). Such a large
result is strongly constrained by requiring that the model parameters fit the
spectrum; we show that this implies a large ``effective'' light mass. It is
also supported phenomenologically by a similar situation with heavy baryons, as
well as by experience with nucleon (if one invokes additivity). We also
calculate the couplings to heavy meson excitations, and show that the
Adler-Weisberger sum rule is well saturated by a few levels (in contrast to the
case of small g). We discuss uncertainties of our approach, and rise several
questions which remain to be answered. The main mystery is the large, unusual
discrepancy with QCD sum rules for g, whereas a good agreement is found for
orbital excitations.


title:
Searching for heavy charged Higgs bosons in the neutrino-tau decay mode
  at LHC

abstract:
  We discuss the search for the heavy charged Higgs bosons H^\pm, implicitly of
the Minimal Supersymmetric Standard Model, in the tau-nu decay mode at the LHC.
Compared to the dominant decay mode H^\pm\to bt, the channel suffers from
suppression due to the branching ratio and the lack of direct mass
reconstruction, but the reduced QCD background makes it a feasible channel
especially in the large tan(beta) region. We study the production in `bt
fusion' via bg\to tH^-, and the leading irreducible background bg\to tW^-. Our
results indicate that for the H^\pm mass of greater than 200 GeV and up to 1
TeV and higher, they can be discovered in this channel for a vast range of the
parameter space, down to at least tan(beta)\sim3 and potentially the whole
range of tan(beta) down to 1.5 if the signal selection efficiency can be
improved fourfold. Our analysis is sensitive to top quark identification at
large rapidity, and should be supplemented with a full study including jet
showering and detector effects.


title:
Pseudo-Dirac neutrinos as a potential complete solution to the neutrino
  oscillation puzzle

abstract:
  A solution for the neutrino mass and mixing pattern is proposed which is
compatible with all available experimental data on neutrino oscillations. This
solution involves Majorana neutrinos of the pseudo-Dirac type, i.e. m_Majorana
<< m_Dirac. The solar and atmospheric neutrino observations are mainly
explained as nu_e - nu_e^S and nu_mu - nu_mu^S oscillations, where S indicates
the sterile (``righthanded'') partner of each neutrino generation, while the
LSND result is interpreted in terms of standard nu_mu - nu_e oscillations. The
resulting constraints on nu_mu - nu_tau and nu_tau - nu_tau^S oscillations are
also discussed. This solution leaves room for a hierarchical mass and mixing
scheme with a nu_tau mass in the few eV range, as favoured by some dark matter
scenarios. The apparent conflict with standard Big Bang nucleosynthesis is
addressed and the implications for current and future experiments are
discussed. It is argued that both short and long baseline accelerator neutrino
experiments are needed in order to decide between this solution and other
oscillation scenarios.


title: Inhomogeneity and the Post-Inflationary Universe

abstract:
  We discuss the interaction between perturbations in the inflaton and the
background during the preheating phase in simple inflationary models. By
numerically solving the Einstein field equations we are able to assess the
impact of non-linear gravitational effects on preheating, and to assess the
accuracy of perturbative discussions of the preheating epoch.


title: Indirect Detection of Neutralino Annihilation from Three-body Channels

abstract:
  Three-body final states are included in the calculation of cross section and
neutrino production in neutralino annihilations. In some regions of the
parameter space, three-body channels maybe important and can enhance the
neutrino flux by a few times.


title: Gauged Monopole-Bubble

abstract:
  The decay of a metastable false vacuum by bubble nucleation is studied in the
high temperature limit of the gauge theory in which an SO(3) gauge symmetry is
spontaneously broken to an SO(2). The effects of internal symmetry are so
drastic that, in addition to the known Euclidean bounce solution, there exists
a new bubble solution involving a 't Hooft-Polyakov monopole at its center the
moment it is nucleated. The decay rate and evolution are analyzed.


title: Unitarity, (anti)shadowing and the black disc limit

abstract:
  By using realistic models for elastic hadron scattering we demonstrate that
at present accelerator energies the $s$-channel unitarity bound is safe, not to
be reached until $10^5$ GeV, while the black disc limit is saturated around 1
TeV. It will be followed by a larger transparency of the scattered particles
near the center.


title:
Irreducible QCD backgrounds to top searches in semi-leptonic final
  states at the Next Linear Collider

abstract:
  At future electron-positron colliders, one of the largest irreducible
backgrounds to top searches in the channel `4 jets + lepton + missing energy'
comes from QCD events of order $\alpha_s^2$. We compute here such processes
exactly at the parton level by resorting to 2 -> 6 matrix elements exploiting
helicity amplitude techniques. We adopt a typical selection procedure based on
the tagging of a high momentum and separated lepton. We finally outline
kinematic differences between signal and background events that can be
exploited to further reduce such a QCD noise.


title: Is there diquark clustering in the nucleon?

abstract:
  It is shown that the instanton-induced interaction in qq pairs, iterated in
t-channel, leads to a meson-exchange interactions between quarks. In this way
one can achieve a simultaneous understanding of low-lying mesons, baryons and
the nuclear force. The discussion is general and does not necessarily rely on
the instanton-induced interaction. Any nonperturbative gluonic interaction
between quarks, which is a source of the dynamical chiral symmetry breaking and
explains the $\pi$ - $\rho$ mass splitting, will imply an effective meson
exchange picture in baryons. Due to the (anti)screening there is a big
difference between the initial 't Hooft interaction and the effective
meson-exchange interaction. It is demonstrated that the effective
meson-exchange interaction, adjusted to the baryon spectrum, does not bind the
scalar diquark and does not induce any significant quark-diquark clustering in
the nucleon because of the nontrivial role played by the Pauli principle.


title: A Dynamical Mechanism for Quark Mixing and Neutrino Oscillations

abstract:
  We show that assuming fermion generations to be given by a gauge symmetry
plus a certain Higgs mechanism for its breaking, the known empirical features
of quark and lepton mixing can be largely explained, including in particular
the fact that the mixing (CKM) matrix element $U_{\mu3}$ responsible for the
muon anomaly in atmospheric neutrinos is near maximal and much larger than
their quark counterparts $V_{cb}$ and $ V_{ts}$, while the corner elements for
both quarks ($V_{ub}, V_{td}$) and leptons ($U_{e3}$) are all very small. The
mechanism also gives automatically a hierarchical fermion mass spectrum which
is intimately related to the mixing pattern.


title: (Super)rare decays of an extra Z' boson via Higgs boson emission

abstract:
  The phenomenological model of an extra U(1) neutral gauge Z' boson coupled to
heavy quarks is presented. In particular, we discuss the probability for a
light $Z_{2}$ mass eigenstate decay into a bound state composed of heavy quarks
via Higgs boson emission.


title:
Phenomenology of single spin asymmetries in p(transv. polarized)-p ->
  pion + X

abstract:
  A phenomenological description of single transverse spin effects in
hadron-hadron inclusive processes is proposed, assuming a generalized
factorization scheme and pQCD hard interactions. The transverse momentum, k_T,
of the quarks inside the hadrons and of the hadrons relatively to the
fragmenting quark, is taken into account in distribution and fragmentation
functions, and leads to possible non zero single spin asymmetries. The role of
k_T and spin dependent quark fragmentations -- the so-called Collins effect --
is investigated in details in p(transv. polarized)-p -> pion + X processes: it
is shown how the experimental data could be described, obtaining an explicit
expression for the spin asymmetry of a polarized fragmenting quark, on which
some comments are made. Predictions for other processes, possible further
applications and experimental tests are discussed.


title:
Anisotropic Type I String Compactification, Winding Modes and Large
  Extra Dimensions

abstract:
  We discuss the structure of general Anisotropic Compactification in Type I
D=4, N=1 string theory. It is emphasized that, in this context, a possible
interpretation of M_{Planck} as ``dual'' to (at least) one of the Kaluza-Klein
or Windings Modes could provide interesting interpretations of the ``physical
scales'' and the GUT coupling. Some of the scenarios presented here are
strictly connected with the phenomenological proposal of TeV-scale gravity
(i.e. millimiter compactification). We show that in this scenario new and
probably dominant effects should arise from the presence of ``low-energy''
Winding Modes of usual SM particles. Stringent bounds on the Planck mass in 4+n
dimensions are derived from the existing experimental limits on massive
replicas of SM gauge bosons. Non-observation of Winding Modes at the planned
accelerators could provide stronger bounds on the 4+n dimensional Planck mass
than those from graviton emission into the bulk. Some comments on other
possible phenomenological interesting scenarios are addressed.


title: A theory of jet definition

abstract:
  A systematic framework for jet definition is developed from first principles
of physical measurement, quantum field theory, and QCD. A jet definition is
found which: is theoretically optimal in regard of both minimization of
detector errors and inversion of hadronization; is similar to a cone algorithm
with dynamically negotiated jet shapes and positions found via shape
observables that generalize the thrust to any number of axes; involves no ad
hoc conventions; allows a fast computer implementation [hep-ph/9912415]. The
framework offers an array of options for systematic construction of
quasi-optimal observables for specific applications.


title: Relations between inclusive decay rates of heavy baryons

abstract:
  The dependence of inclusive weak decay rates of heavy hadrons on the flavors
of spectator light quarks is revisited with application to decays of charmed
and b hyperons. It is pointed out that the differences in the semileptonic
decay rates, the differences in the Cabibbo suppressed decay rates of the
charmed hyperons, and the splitting of the total decay rates of the b hyperons
are all related to the differences in the lifetimes of the charmed hyperons
independently of poor knowledge of hadronic matrix elements. The approximations
used in these relations are the applicability of the expansion in the inverse
of the charmed quark mass and the flavor SU(3) symmetry.


title: Boundary Effects in the Magnetic Catalysis of Chiral Symmetry Breaking

abstract:
  The catalysis of chiral symmetry breaking by an applied constant magnetic
field and in the presence of boundaries along third axis is investigated in the
four-dimensional Nambu-Jona-Lasinio model. It is shown that in case of periodic
boundary conditions for fermions the magnetic field breaks the chiral symmetry,
generating a dynamical mass even at the weakest attractive interaction between
fermions. For antiperiodic boundary conditions the effect of the finite third
dimension is to counteract the chiral symmetry breaking.


title: Comments on the 2nd order bootstrap relation

abstract:
  The 2nd order bootstrap relation is discussed in view of the recent critics
by F.Fadin, R.Fiore y A.Papa. It is shown that the strong bootstrap condition
and the anzatz to solve it used in our earlier paper are valid at least for the
quark part of the next-to-leading contribution.


title: Higher-Order Corrections to Radiative Upsilon Decays

abstract:
  Recent advances in the theoretical description of radiative Upsilon decays
are reviewed, including the calculation of next-to-leading order QCD
corrections to the photon spectrum.


title:
Higgs Mass Bounds in the Three- and Six-Higgs Doublet Models for Family
  Structure

abstract:
  We reanalyze our recently proposed mass matrix model based on spontaneously
broken discrete chiral family symmetry, taking into account the additional
flavor changing neutral current constraint implied by the bound on the
$D_1-D_2$ mass difference, and including several corrections to our earlier
analysis. When combined, the $K_1-K_2$ and $D_1-D_2$ constraints force the
masses of the Higgs particles that contribute most strongly to flavor changing
neutral currents (the $\phi$ Higgs states) to lie above 17 TeV, well beyond the
limit of validity of conventional perturbative Higgs physics. The analogous
constraints on the masses of the $\eta$ Higgs states and the neutral pseudo
Goldstone Higgs state depend on the mechanism for realizing small first family
masses. If the $\eta$ Higgs is the primary contributor to second family masses,
the pseudo Goldstone and $\eta$ Higgs states must have masses above 220 GeV,
with numerical fits suggesting masses above 1 TeV, while if the $\eta$ Higgs is
responsible solely for first family masses, the corresponding mass bounds drop
to the range detectable at the LHC. We show that naturalness of small first
family masses favors the latter alternative, and give an illustrative mass
matrix texture model.


title:
Effects of conversions for high energy neutrinos originating from
  cosmological gamma-ray burst fireballs

abstract:
  We study neutrino conversions in the recently envisaged source of high energy
($E \geq 10^{6}$ GeV) neutrinos, that is, in the vicinity of cosmological
gamma-ray burst fireballs (GRB). We consider mainly the possibility of neutrino
conversions due to an interplay of neutrino transition magnetic moment, $\mu$,
and the violation of equivalence principle (VEP), parameterized by $\Delta f$,
in a reasonable strength of magnetic field in the vicinity of the GRB. We point
out that for $\Delta f \sim 10^{-25}(\delta m^2/1 {eV}^2)$, a resonant
spin-flavour precession between $\bar{\nu}_{\mu}$ and $\nu_{\tau}$ may occur in
the vicinity of GRB for $\mu \sim 10^{-12} \mu_{B}$ ($\mu_{B}$ is Bohr
magneton), thus enhancing the expected high energy $\nu_{\tau}$ flux from GRBs.


title:
Restoring good high energy behaviour in Higgs production via W fusion at
  the LHC

abstract:
  The W-fusion scattering process W+W- --> ZZ for off-shell W bosons is
studied, focusing on the issue of its high-energy behaviour which is known to
be anomalous. It is shown that the unitarity violating terms can be isolated
and extracted in a well-defined and efficient way using the pinch-technique.
This restores the good high energy behaviour of the cross section and, in
particular, makes possible the identification of the Higgs resonance in the
invariant mass distribution M(ZZ) of the Z pair. The discarded terms, which are
proportional to the off-shellness of the W bosons, cancel against similar terms
originating from the remaining diagrams for the full physical process f1 f2 -->
f1' f2' Z Z. This cancellation ensures the gauge invariance of our result,
which therefore constitutes a meaningful separation between signal and
background when they both contribute coherently. Equipped with this result, we
are able to define a resonant approximation for the process p p --> Z Z + 2
jets + X, which circumvents the problem of good high energy behaviour without
having to resort to the lengthy calculation of the complete set of diagrams. In
this approximation only the W and Z fusion signal graphs are included, i.e. the
ones which contain the Higgs resonance. We have verified that the approximate
resonant cross section describes very well the full result not only close to
the resonance but also beyond it.


title: Primordial Black Hole Formation from Inflaton

abstract:
  Measurements of the distances to SNe Ia have produced strong evidence that
the Universe is really accelarating, implying the existence of a nearly uniform
component of dark energy with the simplest explanation as a cosmological
constant. In this paper a small changing cosmological term is proposed, which
is a function of a slow-rolling scalar field, by which the de Sitter primordial
black holes' properties, for both charged and uncharged cases, are carefully
examined and the relationship between the black hole formation and the energy
transfer of the inflaton within this cosmological term is eluciated


title: B-ball Baryogenesis and D-term Inflation

abstract:
  The MSSM has flat directions in its scalar potential, along which it is
natural for Bose condensates of squarks to form in the early Universe. A baryon
asymmetry can be induced in these condensates via Affleck-Dine baryogenesis.
The condensates are unstable with respect to fragmentation to "B-balls",
solitons made of squarks and carrying baryon number, which, if they survive
thermalization, fill the Universe down to low temperatures, much lower than
that of the electroweak phase transition, with interesting cosmological
consequences. In particular, their decay implies a similar number density of
baryons and dark matter neutralinos, in accordance with observations. Evasion
of thermalization and the ability to account for the observed baryon asymmetry
requires a very low reheating temperature, which, it is argued, is a natural
feature of presently favoured D-term inflation models.


title:
Perturbative Constraints on the Slavnov-Taylor Identity for the
  Ghost-Gluon Vertex in QCD

abstract:
  A recent form of the Slavnov-Taylor identity for the ghost-gluon vertex of
QCD is compared with perturbative results. It is found that this identity,
derived assuming ghost-ghost scattering can be neglected, is not consistent
with perturbation theory. A new identity is derived at the one-loop
perturbative level.


title: Meson Properties in a renormalizable version of the NJL model

abstract:
  In the present paper we implement a non-trivial and renormalizable extension
of the NJL model. We discuss the advantages and shortcomings of this extended
model compared to a usual effective Pauli-Villars regularized version. We show
that both versions become equivalent in the case of a large cutoff. Various
relevant mesonic observables are calculated and compared.


title: Neutralino Decays at the CERN LHC

abstract:
  We study the distribution of lepton pairs from the second lightest neutralino
decay \tchi^0_2\to\tchi^0_1 l^+l^-. This decay mode is important to measure the
mass difference between \tchi^0_2 and the lightest neutralino \tchi^0_1, which
helps to determine the parameters of the minimal supersymmetric standard model
at the CERN LHC. We found that the decay distribution strongly depends on the
values of underlying MSSM parameters. For some extreme cases, the amplitude
near the end point of the lepton invariant mass distribution can be suppressed
so strongly that one needs the information of the whole m_{ll} distribution to
extract m_{\tchi^0_2}-m_{\tchi^0_1}. On the other hand, if systematic errors on
the acceptance can be controlled, this distribution can be used to constrain
slepton masses and the Z\tchi^0_2\tchi^0_1 coupling. Measurements of the
velocity distribution of \tchi^0_2 from samples near the end point of the
m_{ll} distribution, and of the asymmetry of the p_T of leptons, would be
useful to reduce the systematic errors.


title: Parity Violating Asymmetries in Top Pair Production at Hadron Colliders

abstract:
  We study loop-induced parity violating asymmetries in the strong production
of polarized top quark pairs at $pp$ and $p \bar p$ colliders. The electroweak
${\cal O}(\alpha)$ corrections to the helicity amplitudes of $q \bar q \to t
\bar t$ and $gg \to t \bar t$ are evaluated in a two Higgs doublet model (2HDM)
and the minimal supersymmetric standard model (MSSM). While observables in top
quark pair production receive little contribution from standard electroweak
interactions, it is possible that they can be significantly enhanced in a 2HDM
and the MSSM. We find that the one-loop MSSM electroweak corrections can
generate parity violating asymmetries in the total production rate of left- and
right-handed top quark pairs up to about 1.7% at the upgraded Tevatron
($\sqrt{S}=2$ TeV) and 3% at the LHC ($\sqrt{S}=14$ TeV).


title: Unusual Properties of the Central Production of Glueballs and Instantons

abstract:
  It is shown that instantons provide a natural mechanism to explain an unusual
azimuthal dependence of the production of the even-parity glueball candidates
in central pp collision. A different azimuthal dependence for instanton-induced
production of the odd-parity glueballs is predicted.


title: Neutrino Masses in E_6 Unification

abstract:
  We show that the neutrino masses with large mixing between \nu_\mu and
\nu_\tau are naturally reproduced in a supersymmetric E_6 grand unification
model with an anomalous U(1)_X symmetry. We propose a simple scenario which
incorporates a novel mechanism called `E-twisting' by which all the
characteristic features of the fermion mass matrices, not only the
quark/lepton's Dirac masses but also the neutrino's Majorana masses, can be
well reproduced despite all the members in 27 of each generation are assigned a
common U(1)_X charge.


title: Determination of heavy-meson wave functions from B decays

abstract:
  We extract the B, D, and D* meson wave functions from the CLEO data of the
decays B -> K*\gamma and B -> D^(*)\pi in the perturbative QCD framework. In
this formalism, various logarithmic corrections are organized to give the
Wilson evolution from the W boson mass down to the characteristic scale of a
decay process, which is of order of the b quark mass, and the Sudakov evolution
from the characteristic scale to a lower factorization scale of order
Lambda_{QCD}. With large logarithms organized, the b quark decay amplitudes are
evaluated reliably in perturbation theory. Below the factorization scale, QCD
dynamics is regarded as being nonperturbative, and absorbed into meson wave
functions. Because of their universality, the heavy-meson wave functions
determined in this work, can be employed to make predictions of other decay
modes. We also observe that the dependence of heavy meson wave functions on
intrinsic parton transverse momenta plays an important role in the explanation
of data.


title:
Neutrino Absorption Tomography of the Earth's Interior using Isotropic
  Ultra-high Energy Flux

abstract:
  We study the feasibility of using an isotropic flux of cosmic neutrinos in
the energy range of 10 to 10000 TeV to study the interior structure of Earth.
The angular distribution of events in a $\sim {\rm km}^3$-scale neutrino
telescope can be inverted to yield information on the Earth's mass distribution
that is independent of other methods. The energy spectrum of the neutrino
primaries is also determined from consistency with the angular distribution. It
is possible to make a model independent determination of the density profile of
Earth's interior, separate from the absolute normalization of the incident
cosmic neutrinos.


title: Phase-shift analysis of low-energy pi+ p data

abstract:
  This work presents the results of a revised analysis of the low-energy (pion
laboratory kinetic energy T(sub pi) < 100 MeV) pi+ p data using recently
obtained electromagnetic corrections. The measurements are analyzed assuming
extended threshold expansions for the hadronic K-matrix elements. With a few
exceptions, the description of the experimental data is satisfactory. Several
minimization functions have been used, yielding consistent results. The
phase-shift values, obtained in the s and p(3/2) partial waves, disagree with
those of the most recent VPI global-fit solution (SP98); the largest part of
this disagreement is removed if we compare our numbers to their single-energy
solutions. The s-wave scattering length a(sub 0+), the p-wave scattering
volumes a(sub 1+) and a(sub 1-), as well as the hadronic phase shifts
themselves, obtained herein, are in agreement with recent work using older
electromagnetic corrections; the output of the present work (including
meaningful uncertainties) is tabulated in order to enable straightforward use
in other applications.


title: The B -> X_d l^+ l^- decay in general two Higgs doublet model

abstract:
  The branching ratio, forward-backward asymmetry and CP violating asymmetry
for (B -> X_d l^+ l^-) decay, in framework of the general two Higgs doublet
model, with extra phase angle in the charged-Higgs-fermion coupling, are
calculated. It is shown that studying the CP violating asymmetry is an
efficient tool for establishing new physics.


title: Bose condensation at high temperatures

abstract:
  Bose condensation is usually a low temperature phenomenon due to a low
particle number density. When the number density is kept large compared to the
inverse Compton volume, Bose condensation can occur at a temperature much
higher than the mass of the particle. We can then use a three dimensional
effective theory to study the thermal properties. We compute the transition
temperature for a complex scalar field theory with a small interaction
parameter.


title: Effects of the Nuclear Correlations on the Neutrino-Oxygen Interactions

abstract:
  We perform a calculation of the absolute charged current neutrino- oxygen
events rates relevant in the atmospheric neutrino experiments. The inclusive
reaction cross-section is split into exclusive channels, which are classified
according to the number of \v{C}erenkov rings they produce. The model includes
the effects of residual interaction in a RPA scheme with both nucleon-hole and
Delta-hole excited states and the effects of (np-nh) excitations (n=2,3). Our
result is that although the flavor ratio $\mu/e$ remains almost unaffected by
the nuclear effects considered here and often neglected in the Monte-Carlo
simulations, the absolute events rates are subject to important modifications.


title: QCD Amplitudes in the High-Energy Limit

abstract:
  Dijet production with a rapidity gap between the jets is considered as a test
ground for the production of a heavy Higgs boson via weak-boson fusion at
hadron supercolliders. It is argued that in order to perform a detailed
analysis of dijet production with a rapidity gap we need an ${\cal O}(\al_s^4)$
calculation including the relevant collinear enhancements which give structure
to the jets. Such a calculation needs not be exact, but must include the full
leading power in $\hat{s}/\hat{t}$ of the rate of dijet production in the
high-energy limit. The QCD amplitudes must be determined to the corresponding
accuracy. Accordingly, the scattering amplitudes necessary to compute the full
leading power in $\hat{s}/\hat{t}$ of dijet production to ${\cal O}(\al_s^3)$
are analysed.


title: Theoretical aspects of high--Q^2 deep inelastic scattering

abstract:
  We present an overview of the theory of high--Q^2 deep inelastic scattering.
We focus in particular on the theoretical uncertainties in the predictions for
neutral and charged current cross sections obtained by extrapolating from lower
Q^2.


title: QCD

abstract:
  This is the written version of the lecture on deep inelastic scattering and
related topics in QCD, delivered in the course of the XXVI International
Meeting on Fundamental Physics to an audience of young experimentalists. The
aim is fundamentally pedagogical. I review the theoretical setting of the
Altarelli-Parisi equations, discuss recent determinations of $\alpha_s$ from
deep-inelastic scattering and then move to the kinematical region explored by
HERA. In the way I mention some unsolved theoretical problems. I discuss low-x
physics and to what extent $\log{1/x}$ resummations are called for.


title:
The process `e+ e- --> H t t-bar' and its backgrounds at future
  electron-positron colliders

abstract:
  The process $e^+e^-\to H t\bar t$ can be used at the Next Linear Collider to
measure the Higgs-top Yukawa coupling. In this paper, we compute $2\to 8$
processes of the form $e^+e^-\to b\bar b b\bar b W^+W^-\to b\bar b b\bar b
\ell^\pm\nu_\ell q\bar q'$, accounting for the Higgs-top-antitop signal as well
as several irreducible backgrounds in the semi-leptonic top-antitop decay
channel. We restrict ourselves to the case of a light Higgs boson in the range
100 GeV $\le M_H \le$ 140 GeV. We use helicity amplitude techniques to compute
exactly such processes at tree level in the framework of the Standard Model.
Total rates and differential spectra of phenomenological interest are given and
discussed


title: May We Expect CP- and T-Violating Effects in Neutrino Oscillations?

abstract:
  Neutrino oscillations with three lepton families are described with a unitary
mixing matrix U in analogy to the quark mixing matrix V(CKM). If U contains a
nontrivial phase, there will be CP- and T-violating asymmetries at distances
large compared to E/D**2, where D**2 is the largest difference of neutrino mass
squares. The paper presents explicit expressions for these distance-dependent
asymmetries.


title: Elementary Excitations of a Relativistic Scalar Plasma System

abstract:
  We investigate the physics of elementary excitations for the so called
relativistic scalar plasma system. Following the standard many-body procedure
we have obtained the RPA equations for this model by linearizing the TDHFB
equations of motion around equilibrium and shown that these oscillation modes
give one-meson and two-fermion state of the theory. The resulting equations
have a closed solution, from which one can examinate the spectrum of excitation
modes. In partticular, our results indicate existence of bound state for
certain region of phase diagram.


title: Pade-Improved Extraction of $\alpha_s(M_\tau)$ from $R_\tau$

abstract:
  The perturbative series used to extract $\alpha_s(M_\tau)$ from the $\tau$
hadronic width exhibits slow convergence. Asymptotic Pade-approximant and Pade
summation techniques provide an estimate of these unknown higher-order effects,
leading to values for $\alpha_s(M_\tau)$ that are about 10% smaller than
current estimates. Such a reduction improves the agreement of
$\alpha_s(M_\tau)$ with the QCD evolution of the strong coupling constant from
$\alpha_s(M_z)$.


title:
Damping Rates and Mean Free Paths of Soft Fermion Collective Excitations
  in a Hot Fermion-Gauge-Scalar Theory

abstract:
  We study the transport coefficients, damping rates and mean free paths of
soft fermion collective excitations in a hot fermion-gauge-scalar plasma with
the goal of understanding the main physical mechanisms that determine transport
of chirality in scenarios of non-local electroweak baryogenesis. The focus is
on identifying the different transport coefficients for the different branches
of soft collective excitations of the fermion spectrum. These branches
correspond to collective excitations with opposite ratios of chirality to
helicity and different dispersion relations. By combining results from the hard
thermal loop (HTL) resummation program with a novel mechanism of fermion
damping through heavy scalar decay, we obtain a robust description of the
different damping rates and mean free paths for the soft collective excitations
to leading order in HTL and lowest order in the Yukawa coupling. The space-time
evolution of wave packets of collective excitations unambiguously reveals the
respective mean free paths. We find that whereas both the gauge and scalar
contribution to the damping rates are different for the different branches, the
difference of mean free paths for both branches is mainly determined by the
decay of the heavy scalar into a hard fermion and a soft collective excitation.
We argue that these mechanisms are robust and are therefore relevant for
non-local scenarios of baryogenesis either in the Standard Model or extensions
thereof.


title: Neutrino Dark Matter

abstract:
  There is a puzzling contradiction: direct observations favor a low-mass
density universe, but the only model which fits universe structure over more
than three orders of magnitude in distance scale has a mix of hot (neutrino)
and cold dark matter consistuting a critical density universe. If all present
indications for neutrino mass are valid, that hot dark matter is shared by two
neutrino species (nu_mu and nu_tau). These results also require at least one
light sterile neutrino to exist to explain the solar nu_e deficit (nu_e ->
nu_s), so that nu_mu -> nu_tau accounts for the atmospheric neutrino anomaly,
with anti-nu_mu -> anti-nu_e being observed in the LSND experiment. This
experiment, when analyzed appropriately, does not conflict with any others and
is compatible with the mass difference needed for dark matter. Support for this
mass pattern is provided by the need for a sterile neutrino to make possible
heavy-element nucleosynthesis in supernovae.


title: Was the Electroweak Phase Transition Preceded by a Color-Broken Phase?

abstract:
  It has been suggested, in connection with electroweak baryogenesis in the
Minimal Supersymmetric Standard Model (MSSM), that the right-handed top squark
has a negative mass squared parameter, such that its field could condense prior
to the electroweak phase transition (EWPT). Thus color and electric charge
could have been broken just before the EWPT. Here we investigate whether the
tunneling rate from the color-broken vacuum can ever be large enough for the
EWPT to occur in this case. We find that, even when all parameters are adjusted
to their most favorable values, the nucleation rate is many orders of magnitude
too small. We conclude that, without additional physics beyond the MSSM, the
answer to our title question is ``no.'' This gives constraints in the plane of
the light stop mass versus parameters related to stop mixing. However it may be
possible to get color breaking in extended models, such as those with R-parity
violation.


title:
Simple analytical representation for the high-energy Delbruck scattering
  amplitudes

abstract:
  Using a new representation for the quasiclassical Green function of the Dirac
equation in a Coulomb field, analytical expressions for the high-energy
small-angle Delbr\"uck scattering amplitudes are obtained exactly in the
parameter Z\alpha. Magnitudes of the amplitudes coincide with the previous
results. However, the structure of the expressions obtained is much more
simple, which considerably facilitates numerical calculations.


title: Spin-flavour conversions of neutrinos in collapsing stars

abstract:
  I discuss in some detail the spin-flavour conversions of neutrinos in the
almost isotopically neutral region of collapsing stars along with the resulting
experimental signatures. In particular, I show that for realistic magnetic
field strength, the observable effects may exist for neutrino magnetic moment,
$\mu \sim (2-3)\times 10^{-14}\mu_B$ ($\mu_B$ is the Bohr magneton) with
relevant neutrino mass squared difference, $\Delta m^2 \sim (10^{-9}-10^{-8})
eV^2$.


title:
The CP asymmetry for B--> K^* l^+ l^- decay in the general two Higgs
  doublet model

abstract:
  We study CP asymmetry for the exclusive decay B --> K^* l^+ l^- in the two
Higgs doublet model with three level flavor changing neutral currents (model
III). We analyse the dependency of this quantity to the new phase coming from
the complex Yukawa couplings in the theory and we find that there exist a
considerable CP violation for the relevant process. Further, we see that the
sign of the Wilson coefficient C_7^{eff} can be determined by fixing dilepton
mass. Therefore, the future measurements of CP asymmetry for B --> K^* l^+ l^-
decay will give a powerful information about the sign of Wilson coefficient
C_{7}^{eff} and the new physics beyond the SM.


title:
Electromagnetic corrections to the hadronic phase shifts in low energy
  pi+ p elastic scattering

abstract:
  We calculate for the s-, p(1/2)- and p(3/2)-waves the electromagnetic
corrections which must be subtracted from the nuclear phase shifts obtained
from the analysis of low energy pi+ p elastic scattering data, in order to
obtain hadronic phase shifts. The calculation uses relativised Schroedinger
equations containing the sum of an electromagnetic potential and an effective
hadronic potential. We compare our results with those of previous calculations
and qualitatively estimate the uncertainties in the corrections.


title: Spin physics in deep inelastic scattering: Summary

abstract:
  The problem of our understanding of the spin structure of the nucleon has
been with us since the publication of the EMC measurements of the polarised
structure function of the proton in 1987. In this talk a review of the results
presented in Working Group 6 at this workshop is given.


title:
Constraints on the Higgs Boson Mass from Direct Searches and Precision
  Measurements

abstract:
  We combine, within the framework of the Standard Model, the results of Higgs
search experiments with the information coming from accurate theoretical
calculation and precision measurements to provide a probability density
function for the Higgs mass, from which all numbers of interest can be derived.
The expected value is 170 GeV, with an expectation uncertainty, quantified by
the standard deviation of the distribution, of about 80 GeV. The median of the
distribution is 150 GeV, while 75 % of the probability is concentrated in the
region $M_H \leq 200$ GeV. The 95 % probability upper limit comes out to be
around 300 GeV.


title: Recent Progress in Baryogenesis

abstract:
  I give a synopsis, specifically aimed at nonexperts, of some of the recent
developments in electroweak baryogenesis. The focus of the talk is on the
present status of electroweak baryogenesis in supersymmetric models, since this
is a plausible and realistic possibility that is currently being probed by
experimental searches for the Higgs boson and the top squark. The question of
whether it is viable to have a period of color-breaking during the electroweak
phase transition is also discussed.


title: Deviations from Lorentz Invariance for Ultrahigh-Energy Fermions

abstract:
  In a new theory, local Lorentz invariance is a low-energy symmetry which no
longer holds when a fermion energy E is well above 1 TeV. Here we find that the
modified E(p) relation is consistent with observation, and is in fact nearly
the same as in Einstein relativity. On the other hand, there is a strong
modification of the fermion equation of motion and propagator at ultrahigh
energy, which should lead to observable effects.


title:
New Results on Perturbative Color Transparency in Quasi-Exclusive
  Electroproduction

abstract:
  We review the perturbative QCD formalism of hadronic electromagnetic form
factors and the color transparency ratio for quasi-exclusive electroproduction
of the proton and pion from nuclear targets. We have completed the first full
calculations including all leading order quark subprocesses and integrations
over distribution amplitudes, including Sudakov effects. For the case of the
proton, the calculated result shows scaling beyond $Q^2=10$ GeV$^2$. The
calculation incorporating filtering due to the nuclear medium is cleaner than
the corresponding calculation in free space because of attenuation of large
distance amplitudes. We find that the color transparency ratio is rather
insensitive to theoretical uncertainties inherent in the perturbative
formalism, such as the choice of the hadron distribution amplitude.


title:
The gamma gamma to gamma gamma process in the Standard and SUSY models
  at high energies

abstract:
  We study the helicity amplitudes of the process \gamma \gamma \to \gamma
\gamma at high energy, which in the standard and SUSY models first arise at the
one-loop order. In the standard model (SM), the diagrams involve W and charged
quark and lepton loops, while in SUSY we also have contributions from chargino,
charged sfermion and Higgs loop diagrams. The SUSY contributions are most
important in the region above the threshold for producing the supersymmetric
partners; since there, they interfere most effectively with the primarily
imaginary SM amplitudes. Simple expressions for the relevant 1-loop functions
are given, which provide a direct overview of the behaviour of the helicity
amplitudes in the whole parameter space at high energies. The various
characteristics of a large set of observables are studied in detail.


title:
Dynamics of Fermions and Inhomogeneous Bose Fields on a Real-Time
  Lattice

abstract:
  The dynamics of the 1+1 abelian Higgs model with fermions is studied in the
large N_f approximation, on a real-time lattice. The Bose fields obey effective
classical equations of motion which include the fermion back reaction. The
dynamics of the quantized fermion field is treated with a mode function
expansion. Numerical results are shown for renormalizability, nonequilibrium
dynamics and the anomalous charge, and Pauli blocking.


title: Baryon and Antibaryon Production in Hadronic and Nuclear Interactions

abstract:
  We introduce a new formulation of the diquark breaking mechanism which
describes with no free parameters the huge nuclear stopping observed in central
nucleus-nucleus collisions. Supplemented, in the dual parton model, with
strings originating from diquark--antidiquark pairs from the nucleon sea, it
gives a substantial increase of hyperon and antihyperon yields from $pPb$ to
central $PbPb$ collisions. Compared to data, this increase is slightly
underestimated for $\Lambda$'s and $\Xi$'s but is five times too small for
$\Omega$'s. Introducing final state interactions, a reasonable description of
all baryon and antibaryon yields is achieved.


title:
Perturbative-nonperturbative interference in the static QCD interaction
  at small distances

abstract:
  Short distance static quark--antiquark interaction is studied systematically
using the background perturbation theory with nonperturbative background
described by field correlators. A universal linear term
$\frac{6N_c\alpha_s\sigma r}{2\pi}$ is observed at small distance $r$ due to
the interference between perturbative and nonperturbative contributions.
Possible modifications of this term due to additional subleading terms are
discussed and implications for systematic corrections to OPE are formulated.


title:
Sudakov Logarithm Resummation in Transverse Momentum Space for
  Electroweak Boson Production at Hadron Colliders

abstract:
  A complete description of W and Z boson production at high-energy hadron
colliders requires the resummation of large Sudakov double logarithms which
dominate the transverse momentum (q_T) distribution at small q_T. We compare
different prescriptions for performing this resummation, in particular implicit
impact parameter space resummation versus explicit transverse momentum space
resummation. We argue that the latter method can be formulated so as to retain
the advantages of the former, while at the same time allowing a smooth
transition to finite order dominance at high q_T.


title: Precision tests and searches for New Physics with K decays

abstract:
  A short overview of FCNC and CP-violating observables in K decays is
presented. Particular attention is paid to the possibility of performing
precision tests of flavour dynamics and to the search for New Physics.


title: The small $x$ nuclear shadowing at DIS

abstract:
  We estimate the perturbative nuclear shadowing in the nuclear structure
function $F_2^A(x,Q^2)$, mainly at the kinematic region of HERA using the
Glauber-Mueller approach. The contributions of the quark and gluon sectors to
the nuclear shadowing are estimated. We predict that the nuclear shadowing
corrections are important and that saturation of the ratio $R_1 =
F_2^{A}(x,Q^2)/A F^p_2(x,Q^2)$ occurs once the shadowing in the gluon sector is
considered.


title:
Annual Modulation Signature for the Direct Detection of Milky Way Wimps
  and Supergravity Models

abstract:
  An analysis is given of the annual modulation signal for the direct detection
of relic neutralinos within the framework of supergravity unified models. It is
shown that both the minimal and the non-minimal SUGRA models can generate
neutralino-proton cross-sections at the level compatible with the signals
reported in the DAMA experiment at the Gran Sasso National Laboratory. Effects
of proton stability on the analysis of the DAMA data in the minimal and the
non-minimal SUGRA models are also discussed.


title:
eta' to eta pi pi Decay as a Probe of a Possible Lowest-Lying Scalar
  Nonet

abstract:
  We study the eta' to eta pi pi decay within an effective chiral Lagrangian
approach in which the lowest lying scalar meson candidates sigma(560) and
kappa(900) together with the f0(980) and a0(980) are combined into a possible
nonet. We show that there exists a unique choice of the free parameters of this
model which, in addition to fitting the pi pi and pi K scattering amplitudes,
well describes the experimental measurements for the partial decay width of
eta' to eta pi pi and the energy dependence of this decay. As a by-product, we
estimate the a0(980) width to be 70 MeV, in agreement with a new experimental
analysis.


title:
Gauge Invariant and Infrared Finite Theory of Nonleptonic Heavy Meson
  Decays

abstract:
  We show that the controversies on the gauge dependence and the infrared
singularity emerged in the generalized factorization approach for nonleptonic
heavy meson decays within the framework of the operator product expansion can
be resolved by perturbative QCD factorization theorem. Gauge invariance of the
decay amplitude is maintained under radiative corrections by assuming on-shell
external quarks. For on-shell external quarks, infrared poles in radiative
corrections have to be extracted using the dimensional regularization. These
poles, signifying nonperturbative dynamics of a decay process, are absorbed
into bound-state wave functions. Various large logarithms produced in radiative
corrections are summed to all orders into the Wilson and Sudakov evolution
factors. The remaining finite part gives a hard subamplitude. A decay rate is
then factorized into a convolution of the hard subamplitude, the Wilson
coefficient, and the Sudakov factor with the bound-state wave functions, all of
which are well-defined and gauge invariant.


title:
The breaking of the flavour permutational symmetry: Mass textures and
  the CKM matrix

abstract:
  This paper has been withdrawn by the authors, and instead we have replaced
hep-ph/9807214 by this new version.


title:
High twist contribution to the longitudinal structure function $F_L$ at
  high $x$

abstract:
  We performed NLO QCD fit of combined SLAC/BCDMS/NMC DIS data at high $x$.
Model independent x-shape of high twist contribution to structure function
$F_L$ is extracted. Twist-4 contribution is found to be in fair agreement with
the predictions of infrared renormalon model. Twist-6 contribution exhibits
weak tendency to negative values, although in the whole is compatible with zero
within errors.


title: Superheavy Supersymmetry

abstract:
  One way to suppress flavor changing neutral currents or CP violating
processes in supersymmetry is to make at least some of the first two
generations' scalars superheavy (above ~20 TeV). We summarize the motivations
and challenges, theoretically and phenomenologically, for superheavy
supersymmetry. We then argue for more viable alternatives on the superheavy
theme and are led to models where the heavy spectrum follows a pattern of
masses similar to what arises from gauge-mediation or with a "hybrid" spectrum
of light and heavy masses based on each particle's transformation under a
global SU(5). In the end, despite the differences between the competing ideas,
a self-consistent natural theory with superheavy masses seems to prefer
low-energy supersymmetry breaking with possible correlations among the light
sparticle masses. The resulting light gravitino and its couplings to matter
could also impact the discovery capabilities and analyses of these models at
colliders. In addition, we comment on how the presence of superheavy states may
influence the light spectrum, and how this may help efforts to distinguish
between theories post-discovery.


title: Central production of mesons: Exotic states versus Pomeron structure

abstract:
  We demonstrate that the azimuthal dependence of central meson production in
hadronic collisions, when suitably binned, provides unambiguous tests of
whether the Pomeron couples like a conserved vector-current to protons. We
discuss the possibility of discriminating between q-qbar and glueball
production in such processes. Our predictions apply also to meson production in
tagged two-photon events at electron--positron colliders and to vector-meson
production in ep collisions at HERA.


title: Borel summation and momentum-plane analyticity in perturbative QCD

abstract:
  We derive a compact expression for the Borel sum of a QCD amplitude in terms
of the inverse Mellin transform of the corresponding Borel function. The result
allows us to investigate the momentum-plane analyticity properties of the
Borel-summed Green functions in perturbative QCD. An interesting connection
between the asymptotic behaviour of the Borel transform and the Landau
singularities in the momentum plane is established. We consider for
illustration the polarization function of massless quarks and the resummation
of one-loop renormalon chains in the large-$\beta_0$ limit, but our conclusions
have a more general validity.


title:
Bethe-Heitler cross-section for very high photon energies and large muon
  scattering angles

abstract:
  The cross-section for the process $\gamma + A \to \mu^+ + \mu^- + X$ is
studied where the photon energy is of the order of several hundreds of GeV and
where one of the leptons is scattered to large angles. This is of practical
importance for muon shielding calculations at future linear electron colliders.
In addition to the photon pole contribution which was previously considered
especially by Y.S.Tsai, we identify another component due to the muon pole
(equivalent photon and equivalent muon approximation). This is discussed
following the usual Bethe-Heitler formula. Then we give practically useful
formulae for inclusive lepton (muon) production along with some numerical
examples.


title: Is topological Skyrme Model consistent with the Satandard Model?

abstract:
  The topological Skyrme model is known to give a successful description of
baryons. As a consistency check, here it is shown that in view of the recent
discovery of charge quantization as an intrinsic and basic property of the
Standard Model and the color dependence arising therein, the Skyrme Model is
indeed completely consistent with the Standard Model.


title: Physics Implications of a Perturbative Superstring Construction

abstract:
  We investigate the low energy physics implications of a prototype
quasi-realistic superstring model with an anomalous U(1). First, we present the
techniques utilized to compute the mass spectrum and superpotential couplings
at the string scale, and demonstrate the results for the effective theory along
a particular flat direction/"restabilized vacuum" of the model. We then analyze
the gauge symmetry breaking patterns and renormalization group equations to
determine the mass spectrum at the electroweak scale for a particular numerical
example with a realistic Z-Z' hierarchy. Although the model considered is not
fully realistic, the results demonstrate general features of quasi-realistic
string models, such as extra matter (e.g. Z' gauge bosons and an extended Higgs
sector) at the electroweak/TeV scale, and noncanonical couplings (such as
R-parity violating terms).


title:
The gluon field of a fast moving nucleus and the effective langrangian
  for QCD at high energy

abstract:
  Starting from the effective lagrangian for QCD at high energy we calculate
the lowest perturbative contributions to the potential of a relativistic
nucleus and compare our results to those derived by Kovchegov (see Y.V.
Kovchegov, Phys. Rev. {\bf D55}, 5445 (1997)). The results differ already at
order g^3 which can be traced to the fact that the meaning of the underlying
gluon fields is different. (The effective gluon field we use is a gauge
invariant object.) Both approaches should therefore be seen as alternatives,
the relative merits of which have to be judged by their phenomenological
success.


title: A variational fit to the lattice energy of two heavy-light mesons

abstract:
  Recent lattice calculations on the interaction energy of two heavy-light
mesons (Q^2\bar{q}^2) are interpreted in terms of the potential of the
corresponding single heavy-light meson (Q\bar{q}). This model leads to a large
overestimate of the binding compared with the lattice data -- unless the basic
Q\bar{q} potential is modified to become a four-quark potential.


title:
Transverse Double-Spin Asymmetries for Muon Pair Production in
  pp-Collisions

abstract:
  We calculate the rapidity dependence of the transverse double-spin asymmetry
for the Drell-Yan process to next-to-leading order in the strong coupling.
Input transversity distributions are obtained by saturating the Soffer
inequality at a low hadronic mass scale. Results for the polarized BNL-RHIC
proton-proton collider and the proposed HERA-N fixed-target experiment are
presented, and the influence of the limited muon acceptance of the detectors on
measurements of the asymmetry is studied in detail.


title:
2-Loop Supersymmetric Renormalisation Group Equations Including R-Parity
  Violation and Aspects of Unification

abstract:
  We present the complete 2-loop renormalisation group equations of the
superpotential parameters for the supersymmetric standard model including the
full set of R-parity violating couplings. We use these equations to do a study
of (a) gauge coupling unification, (b) bottom-tau unification, (c) the
fixed-point structure of the top quark Yukawa coupling, and (d) two-loop bounds
from perturbative unification. For large values of the R-parity violating
coupling, the value of \alpha_S(M_Z) predicted from unification can be reduced
by 5% with respect to the R-parity conserving case, bringing it to within
2\sigma of the observed value. Bottom-tau Yukawa unification becomes
potentially valid for any value of \tan\beta\sim 2-50. The prediction of the
top Yukawa coupling from the low \tan\beta, infra-red quasi fixed point can be
lowered by up to 10%, raising \tan\beta up to a maximum of 5 and relaxing
experimental constraints upon the quasi-fixed point scenario. For heavy scalar
fermion masses of order 1 Tev the limits on the higher family \Delta L\not=0
operators from perturbative unification are competitive with the indirect
laboratory bounds. We calculate the dependence of these bounds upon \tan \beta.


title:
Depth of maximum of extensive air showers and cosmic ray composition
  above 10**17 eV in the geometrical multichain model of nuclei interactions

abstract:
  The depth of maximum for extensive air showers measured by Fly's Eye and
Yakutsk experiments is analysed. The analysis depends on the hadronic
interaction model that determine cascade development. The novel feature found
in the cascading process for nucleus-nucleus collisions at high energies leads
to a fast increase of the inelasticity in heavy nuclei interactions without
changing the hadron-hadron interaction properties. This effects the development
of the extensive air showers initiated by heavy primaries. The detailed
calculations were performed using the recently developed geometrical multichain
model and the CORSIKA simulation code. The agreement with data on average depth
of shower maxima, the falling slope of the maxima distribution, and these
distribution widths are found for the very heavy cosmic ray mass spectrum
(slightly heavier than expected in the diffusion model at about 3*10**17 eV and
similar to the Fly's Eye composition at this energy).


title: Measurements of electroweak couplings of the tau lepton at L3

abstract:
  We review the current knowledge of the couplings of the tau lepton to the
electroweak gauge bosons, the W, Z and photon, obtained from the full L3 data
sample at center-of-mass energies near the Z mass. Measurements of the the
effective vector and axial-vector weak neutral couplings of the $\tau$, the
Lorentz structure of the weak charged current, and anomalous couplings of the
electroweak gauge bosons to the tau are presented.


title: Relaxing Axions

abstract:
  A mechanism for lifting the cosmological upper bound on the axion decay
constant, $f_a$, is proposed. It entails the near masslessness of the radial
mode whose vacuum expectation value is $f_a$. Energy in the coherent
oscillations of the axion field in the early universe gets fed into the motion
of the radial mode, from which it is then redshifted away.


title: Investigating the origins of transverse spin asymmetries at RHIC

abstract:
  We discuss possible origins of transverse spin asymmetries in hadron-hadron
collisions and propose an explanation in terms of a chiral-odd T-odd
distribution function with intrinsic transverse momentum dependence, which
would signal a correlation between the transverse spin and the transverse
momentum of quarks inside an unpolarized hadron. We will argue that despite its
conceptual problems, it can account for single spin asymmetries, for example in
p + p(transversely polarized) -> pion + X, and at the same time for the large
cos(2 phi) asymmetry in the unpolarized Drell-Yan cross section, which still
lacks understanding. We use the latter asymmetry to arrive at a crude model for
this function and show explicitly how it relates unpolarized and polarized
observables in the Drell-Yan process, as could be measured with the
proton-proton collisions at RHIC. Moreover, it would provide an alternative
method of accessing the transversity distribution function h_1. For future
reference we also list the complete set of azimuthal asymmetries in the
unpolarized and polarized Drell-Yan process at leading order involving T-odd
distribution functions with intrinsic transverse momentum dependence.


title: Indications for Factorization and $Re V_{ub} < 0$ from Rare B Decay Data

abstract:
  Surveying known hadronic rare B decays, we find that the factorization
approximation can give a coherent account of $K\pi$, $\pi\pi$ and $\rho^0\pi^+$
data and give predictions for $\omega^0\pi^+$, $\rho\pi$ and $K^*\pi$ modes,
{\it if ${Re}V_{ub}$ is taken as negative} (in standard phase convention)
rather than positive. As further confirmation, we expect a lower $\sin2\beta$
value at B Factories as compared to current fits, and $B_s$ mixing close to LEP
bounds at SLD and CDF.


title: An Improved Determination of the Fermi Coupling Constant, G_F

abstract:
  Over 40 years after the calculation of the 1-loop QED corrections to the muon
lifetime, new theoretical developments have made it possible to obtain an
analytic expression for the complete 2-loop QED contributions in the Fermi
theory. The exact result for the effects of virtual and real photons, virtual
electrons, muons and hadrons as well as e+e- pair creation is
  Delta Gamma^(2)=Gamma_0(alpha/pi)^2[(156815/5184)-(1036/27)zeta(2)
  -(895/36)zeta(3)+(67/8)zeta(4)
  +53zeta(2)ln(2)-(0.042+/-0.002)]
  where Gamma_0 is the tree-level width. This eliminates the theoretical error
in the extracted value of the Fermi coupling constant, G_F, which was
previously the source of the dominant uncertainty. The new value is
  G_F=(1.16637 +/- 0.00001) x 10^-5 GeV^-2
  The overall error has been roughly halved and is now entirely experimental.
Several experiments are planned for the next generation of muon lifetime
measurements and these can proceed unhindered by theoretical uncertainties.


title:
Structure functions in the polarized Drell-Yan processes with spin-1/2
  and spin-1 hadrons: II. parton model

abstract:
  We analyze the polarized Drell-Yan processes with spin-1/2 and spin-1 hadrons
in a parton model. Quark and antiquark correlation functions are expressed in
terms of possible combinations of Lorentz vectors and pseudovectors with the
constrains of Hermiticity, parity conservation, and time-reversal invariance.
Then, we find tensor polarized distributions for a spin-1 hadron. The naive
parton model predicts that there exist 19 structure functions. However, there
are only four or five non-vanishing structure functions, depending on whether
the cross section is integrated over the virtual-photon transverse momentum
\vec Q_T or the limit Q_T->0 is taken. One of the finite structure functions is
related to the tensor polarized distribution b_1, and it does not exist in the
proton-proton reactions. The vanishing structure functions should be associated
with higher-twist physics. The tensor distributions can be measured by the
quadrupole polarization measurements. The Drell-Yan process has an advantage
over the lepton reaction in the sense that the antiquark tensor polarization
could be extracted rather easily.


title: Exclusive Vector Meson Production in Relativistic Heavy Ion Collisions

abstract:
  Exclusive vector meson production reactions such as $Au + Au \to Au + Au +
V$, where $V=\rho, \omega, \phi$ or $J/\psi$ can proceed through photon-Pomeron
and photon-meson interactions. Photons from the electromagnetic field of one
nucleus interact coherently with the other nucleus. Photonuclear cross sections
are scaled from $\gamma p$ data, and convoluted with the photon spectrum to
find the exclusive rates.
  The cross sections at the RHIC and LHC heavy ion colliders are huge, 10% of
the total hadronic cross section at RHIC, and 50% at LHC. These accelerators
may be useful as vector meson factories. With iodine beams at RHIC, 640 $\rho$
are produced each second (10^{10}/year); with calcium at the LHC the rate is
240 kHz. The $\phi$ rates are 39 Hz at RHIC and 15 kHz at LHC, while the
$J/\psi$ rate is 0.3 Hz at RHIC and 780 Hz at the LHC.
  Because of the coherent couplings, the reactions kinematics are similar to
coherent two-photon interactions; we discuss the interplay between the two
reactions.


title: Possible Classification of the Chiral Scalar sigma-Nonet

abstract:
  We recently observed the iso-singlet scalar sigma(600)-particle and the
iso-doublet scalar kappa(900)-particle, through the re-analyses of pi pi- and K
pi-scattering phase shifts, respectively. First, assuming the two iso-singlet
states, the sigma(600) and the established f0(980), being the ideal mixing
states n n and s s, respectively, of a single scalar nonet, it is pointed out
that the mass value of the iso-singlet flavor-octet state, obtained from the
orthogonal transformation, satisfies, together with the kappa(900) and the
iso-triplet scalar a0(980)-particle, the Gell-Mann Okubo mass-formula.
Furthermore, it is argued that, by investigating their properties of masses and
widths, this scalar sigma-nonet, together with the pseudo-scalar pi-nonet,
realizes the linear representation of SU(3) chiral symmetry.


title:
Implications of Super-Kamiokande atmospheric low-energy data for solar
  neutrino oscillations

abstract:
  It is shown that the high-Delta m^2 part of the large mixing angle MSW
solution of the solar neutrino problem is disfavored by the Super-Kamiokande
data for low-energy upward-going events. A quantitative bound is obtained in
the three-neutrino scheme with a negligibly small element U_{e3} of the
neutrino mixing matrix, as indicated by the result of the CHOOZ long-baseline
antinu_e->antinu_e oscillation experiment.


title:
Asymptotic properties of Born-improved amplitudes with gauge bosons in
  the final state

abstract:
  For processes with gauge bosons in the final state we show how to
continuously connect with a single Born-improved amplitude the resonant region,
where resummation effects are important, with the asymptotic region far away
from the resonance, where the amplitude must reduce to its tree-level form.
While doing so all known field-theoretical constraints are respected, most
notably gauge-invariance, unitarity and the equivalence theorem. The
calculations presented are based on the process $f\bar{f}\to ZZ$, mediated by a
possibly resonant Higgs boson; this process captures all the essential
features, and can serve as a prototype for a variety of similar calculations.
By virtue of massive cancellations the resulting closed expressions for the
differential and total cross-sections are particularly compact.


title:
Limits on Low Scale Gravity from $e^+ e^- \to W^+ W^-, ZZ$ and $\gamma
  \gamma$

abstract:
  It has been proposed recently that the scale of quantum gravity (``the string
scale'') can be $M_S \sim$ few TeV with $n \geq 2$ extra dimensions of size $R
\stackrel{<}{\sim}$ mm so that, at distances greater than $R$, Newtonian
gravity with $M_{Pl} \sim 10^{18}$ GeV is reproduced if $M_{Pl}^2 \sim R^n
M_S^{n+2}$. Exchange of virtual gravitons in this theory generates
higher-dimensional operators involving SM fields, suppressed by powers of
$M_S$. We discuss constraints on this scenario from the contribution of these
operators to the processes $e^+ e^- \to W^+ W^-, ZZ, \gamma \gamma$. We find
that LEP2 can place a limit $M_S \approx 1$ TeV from $e^+ e^- \to W^+ W^-, ZZ,
\gamma \gamma$.


title:
On the utility and implication of convex effective potential for the
  Higgs particles

abstract:
  It is suggested that within the effective potential approach, convexity and
spontaneous symmetry breaking(SSB) make the Higgs modes (elementary or
effective) complicated in that the normal final states (experimentally
identifiable) for Higgs modes could not be analytically defined. This
observation might have some nontrivial consequences for the Standard Model (SM)
and particle physics.


title: Dileptons and Charm & Bottom in Relativistic Heavy-Ion Collisions

abstract:
  We study the prospects to get information about the early and hot stages of
deconfined matter produced in relativistic heavy-ion collisions by analyzing
dilepton and single-lepton spectra. Energy losses of heavy quarks in deconfined
matter and thermalization effects in hadron matter and their influence on
lepton spectra are considered.


title:
Parameterisation of \sigma_{1/2}-\sigma_{3/2} for Q^2 \geq 0 and
  non-resonance contribution to the GDH sum rule

abstract:
  A description of the virtual photon absorption cross section difference
\sigma_{1/2}-\sigma_{3/2} for the proton and the neutron is obtained with a
parameterisation based on a Regge type approach. The parameterisation is
obtained from global fits to the cross section data derived from the spin
asymmetries measured in DIS of longitudinally polarised leptons from polarised
^1H, ^3He and ^2H targets in the range 0.3 GeV^2 < Q^2 < 70 GeV^2 and 4 GeV^2 <
W^2 < 300 GeV^2. The fits give a reliable description of the data and provide
predictions for the photo-production through a smooth Q^2-transition. The
contribution above the resonance region to the Gerasimov-Drell-Hearn sum rule
for real and virtual photons has been evaluated. For the real photons this
contribution accounts for a large fraction of the discrepancy between the sum
rule expectations and the single pion photo-production analysis estimates


title: Super-Kamiokande data and atmospheric neutrino decay

abstract:
  Neutrino decay has been proposed as a possible solution to the atmospheric
neutrino anomaly, in the light of the recent data from the Super-Kamiokande
experiment. We investigate this hypothesis by means of a quantitative analysis
of the zenith angle distributions of neutrino events in Super-Kamiokande,
including the latest (45 kTy) data. We find that the neutrino decay hypothesis
fails to reproduce the observed distributions of muons.


title: Rho properties in a hot meson gas

abstract:
  Using effective meson Lagrangians we study the interaction of rho mesons in a
hot baryon-free system. Various mesonic resonances in direct $s$-channel
reactions are investigated employing standard self-energy techniques, including
new reactions that have up to now not been considered in a self-consistent
approach at finite temperature. The importance of subthreshold resonances,
which are readily accounted for through off-shell effects within our framework,
is emphasized. Special care is taken in reproducing radiative decay widths, as
they provide valuable constraints on the evaluation of dilepton spectra. In
particular, we compare our results for dilepton production rates to earlier
calculations based on an incoherent summation of individual processes.


title: Effective Magnetic Moment of Neutrinos in Strong Magnetic Fields

abstract:
  We compute the effective magnetic moment of neutrino in the highly dense and
strongly magnetized media. It is shown that this magnetic moment is generated
due to the effective mass of neutrino and gives sufficiently high value of the
magnetic moment in the core of neutron stars.


title: Measuring Trilinear Higgs Couplings in the MSSM

abstract:
  Trilinear couplings of the neutral CP-even Higgs bosons in the Minimal
Supersymmetric Standard Model (MSSM) can be measured through the multiple
production of the lightest CP-even Higgs boson (h) at high-energy e^+e^-
colliders. This includes the production of the heavier CP-even Higgs boson (H)
via e^+e^- \to ZH, in association with the CP-odd Higgs boson (A) in e^+e^- \to
AH, or via e^+e^- \to \nu_e \bar\nu_e H, with H subsequently decaying through H
\to hh. These processes can enable one to measure the trilinear Higgs couplings
\lambda_{Hhh} and \lambda_{hhh}, which can be used to theoretically reconstruct
the Higgs potential. We delineate the regions of the MSSM parameter space in
which these trilinear Higgs couplings could be measured.


title: Neutrino Astrophysics at the Cross Roads

abstract:
  Nonstandard neutrino properties (masses, mixing, sterile states,
electromagnetic interactions, and so forth) can have far-reaching ramifications
in astrophysics and cosmology. We look at the most interesting cases in the
light of the powerful current indications for neutrino oscillations.


title: Quantum Dew

abstract:
  We consider phase separation in nonequilibrium Bose gas with an attractive
interaction between the particles. Using numerical integrations on a lattice,
we show that the system evolves into a state that contains drops of
Bose-Einstein condensate suspended in uncondensed gas. When the initial gas is
sufficiently rarefied, the rate of formation of this quantum dew scales with
the initial density as expected for a process governed by two-particle
collisions.


title:
Top Quark Production at the Tevatron: Probing Anomalous Chromomagnetic
  Moments and Theories of Low Scale Gravity

abstract:
  We review the effects of an anomalous chromomagnetic moment on top quark pair
production at the Tevatron for Run II. Apart from an overall rescaling by the
total cross section these couplings have little influence on top production
characteristics. We then examine how the exchange of a Kaluza-Klein tower of
gravitons arising from the low scale quantum gravity scenario of Arkani-Hamed,
Dimopoulos and Dvali influences top pair cross sections and several associated
kinematical distributions. The data that will be available with Run II
luminosities is shown to be sensitive to values of the effective Planck scale
of order 1 TeV or more.


title: Preheating in Generalized Einstein Theories

abstract:
  We study the preheating scenario in Generalized Einstein Theories,
considering a class of such theories which are conformally equivalent to those
of an extra field with a modified potential in the Einstein frame. Resonant
creation of bosons from oscillating inflaton has been studied before in the
context of general relativity taking also into account the effect of metric
perturbations in linearized gravity. As a natural generalization we include the
dilatonic/Brans-Dicke field without any potential of its own and in particular
we study the linear theory of perturbations including the metric perturbations
in the longitudinal gauge. We show that there is an amplification of the
perturbations in the dilaton/Brans-Dicke field on super-horizon scales (k -> 0)
due to the fluctuations in metric, thus leading to an oscillating Newton's
constant with very high frequency within the horizon and with growing amplitude
outside the horizon. We briefly mention the entropy perturbations generated by
such fluctuations and also mention that there is a possibility to excite the
Kaluza-Klein modes in the theories where the dilatonic/Brans-Dicke field is
interpreted as a homogeneous field appearing due to the dimensional reduction
from the higher dimensional theories.


title:
QCD Anomaly Coupling for the $\eta'-g-g$ Vertex in Inclusive Decay
  $B\to\eta' X_s$

abstract:
  The QCD anomaly coupling of $\eta'-g-g$ is treated as the axial vector
current triangle anomaly. By assuming the divergent axial vector coupling of
the $\eta'$ meson with the quark line in the triangle diagram, we calculate the
QCD anomaly of $\eta'-g-g$ as well as the QED anomaly of $\eta'-\gamma-\gamma$
with only one common parameter $\kappa_{\eta'}$. We obtain consistent results
of the branching ratios for $B\to\eta' X_s, J/\psi\to\eta'\gamma$ and $\eta'\to
\gamma\gamma$ when comparing with experimental data.


abstract:
  We present a calculation of the O(m alpha^7 ln(alpha)^2) corrections to
positronium energy levels. The result is used to estimate the current
uncertainty in theoretical predictions of the positronium spectrum.


title: High Q^2 Deep Inelastic Scattering at HERA

abstract:
  High Q^2 NC and CC cross-sections as measured at HERA can give information on
two distinct areas of current interest. Firstly, supposing that all the
electroweak parameters are well known, these cross-sections may be used to give
information on parton distributions at high x and high Q^2. Secondly, supposing
that parton distributions are well known, after evolution in Q^2 from the
kinematic regime where they are already measured, these cross-sections can be
used to give information on electroweak parameters in a process where the
exchanged boson is `spacelike' rather than `timelike'. WG1 addressed itself to
clarifying the limits of our present and possible future knowledge on both
these areas.


title: Comment on "Chiral Corrections in Hadron Spectroscopy"

abstract:
  It is shown that the principal pattern in baryon spectroscopy, which is
associated with the flavor-spin dependent hyperfine interaction, is due to the
spontaneous breaking of chiral symmetry in QCD and thus cannot be addressed by
chiral perturbation theory, which is based on the explicit chiral symmetry
breaking.


title: The theory of quark confinement

abstract:
  This is the second of the two last papers by V. N. Gribov concluding his 20
year long study of the problem of quark confinement in QCD. In this paper the
analytic structure of quark and gluon Green's functions is investigated in the
framework of the theory of confinement based on the phenomenon of supercritical
binding of light quarks. The problem of unitarity in a confining theory is
discussed. The write-up remained unfinished and so it is presented here. The
author was planning to considerably extend the paper. The text was prepared for
publication by Yu. Dokshitzer, C. Ewerz, and J. Nyiri.


title: Constituent Quarks and g_1

abstract:
  We review the theory and present status of the proton spin problem with
emphasis on the transition between current quarks and constituent quarks in
QCD.


title:
Experimental and Theoretical Results for Weak Charge Current Backward
  Proton Production

abstract:
  In this paper, we do three things in the study of deuteron break-up by high
energy neutrino beams. (1) We present previously unpublished data on neutrino
induced backward protons from deuteron targets; (2) we calculate the
contributions from both the two-nucleon (2N) and six-quark (6q) deuteron
components, which depend upon the overall normalization of the part that is 6q;
and (3) we suggest other signatures for distinguishing the 2N and 6q clusters.
We conclude that the 6q cluster easily explains the shape of the high momentum
backward proton spectrum, and its size is nicely explained if the amount of 6q
is one or a few percent by normalization of the deuteron. There is a crossover,
above which the 6q contribution is important or dominant, at 300--400 MeV/c
backward proton momentum.


title: Magnetic fields and the EW phase transition

abstract:
  We review the motivation for, lattice results on, and some implications of,
external magnetic fields present at the time of the cosmological electroweak
phase transition.


title: Neutrino masses from U(1) symmetries and the Super-Kamiokande data

abstract:
  Motivated by the Super-Kamiokande data, we revisit models with U(1)
symmetries and discuss the origin of neutrino masses and mixings in such
theories. We show that, in models with just three light neutrinos and a
hierarchy of neutrino masses, large (2-3) mixing fixes the lepton doublet U(1)
charges and is thus related to the structure of the charged lepton mass matrix.
We discuss the fermion mass structure that follows from the Abelian family
symmetry with an extended gauge group. Requiring that the quark and lepton
masses be ordered by the family symmetry, we identify the most promising
scheme. This requires large, but not necessarily maximal, mixing in the mu-tau
sector and gives small e-mu mixing in the range that is required for the small
angle solution of the solar neutrino deficit.


title: Rare Pionium Decays and Pion Polarizability

abstract:
  We calculate the decay of pionium atoms into two photons. The pion
polarizability gives rise to a 10% correction to the corresponding decay width
for pointlike pions. This opens the possibility to obtain the difference
between the electric and magnetic polarizability of the charged pion from a
future measurement of the branching fraction of pionium into two photons. For
such an experiment the \pi\pi-scattering lengths would have to be known to
better than 5% precision. We also comment on the contribution of the axial
anomaly to the decay of pionium into \gamma\pi^0.


title: Dynamics of Topological Defects in Electroweak Theory

abstract:
  Embedded defects proposed long ago (Z-vortices and Nambu monopoles) have been
successfully searched for in 3D equilibrium lattice studies within the standard
model near the electroweak phase transition and the crossover (which follows it
for realistic Higgs mass). Gauge independent lattice-vortex operators are
proposed. Vortex condensation (percolation) is found to characterize the
high-temperature phase. Small vortex clusters are thermally activated with
non-negligible density on the low-temperature side only at higher Higgs mass,
where preliminary evidence supports their semiclassical nature.


title:
Electroproduction of Transversely Polarized Vector Mesons Via A Quantum
  Mechanical Anomaly

abstract:
  By explicit calculation we demonstrate that, in variance with the classical
prediction, the leading twist contribution to the exclusive electroproduction
of transversely polarized vector mesons from the nucleon does not vanish beyond
the leading order in perturbation theory. This appears to be due to a
quantum-mechanical anomaly, in the sense that a classical symmetry of the field
theory is broken by quantum corrections.


title: Higgs Bounds in Three and Four Generation Scenarios

abstract:
  In light of recent experimental results, we present updated bounds on the
lightest Higgs boson mass in the Standard Model (SM) and in the Minimal
Supersymmetric extension of the Standard Model (MSSM). The vacuum stability
lower bound on the SM Higgs boson mass lies above the MSSM lightest Higgs boson
mass upper bound for a large amount of SUSY parameter space. We postulate a
fourth generation of fermions to see how the area of inconsistency changes, and
discover that the MSSM is salvagable if a fourth generation is added to the
MSSM (MSSM4).


title: A Quantum Field Theory Warm Inflation Model

abstract:
  A quantum field theory warm inflation model is presented that solves the
cosmological horizon/flatness problems. An interpretation of the model is given
from supersymmetry and superstring theory.


title:
Propagation of Gluons From a Non-Perturbative Evolution Equation in
  Axial Gauges

abstract:
  We derive a non-perturbative evolution equation for the gluon propagator in
axial gauges based on the framework of Wetterich's formulation of the exact
renormalization group. We obtain asymptotic solutions to this equation in the
ultraviolet and infrared limits.


title:
Infrared Quasi Fixed Points and Mass Predictions in the MSSM II: Large
  tan(beta) Scenario

abstract:
  We consider the infrared quasi fixed point solutions of the renormalization
group equations for the Yukawa couplings and soft supersymmetry breaking
parameters in the MSSM in the \underline{large $\tan\beta$} regime. The
existence of IR quasi fixed points together with the values of gauge couplings,
third generation quarks, lepton and Z-boson masses allows one to predict masses
of the Higgs bosons and SUSY particles as functions of the only free parameter,
$m_{1/2}$, or the gluino mass. The lightest Higgs boson mass for $M_{SUSY}
\approx 1$ TeV is found to be $m_h=128.2-0.4-7.1 \pm 5$ GeV for $\mu>0$ and
$m_h=120.6-0.1-3.8 \pm 5$ GeV for $\mu<0$.


title:
Cosmological Gravitino Production in Gauge Mediated Supersymmetry
  Breaking Models

abstract:
  We study the cosmological gravitino production in gauge mediated
supersymmetry breaking models, while properly taking into account the existence
of the messenger mass scale. It is found that for sizable parameter range of
the model the messenger sector contribution leads to more stringent upper bound
on the reheat temperature obtained from the condition that the universe should
not be overclosed by relic gravitinos. However it turns out that in the limit
of relatively low messenger scale and large gravitino mass, the relic gravitino
mass density can be smaller than the critical density independently of the
reheat temperature, suggesting the possibility in this limit to have a high
reheat temperature without the dilution of gravitinos at late time.


title: String or M theory axion as a quintessence

abstract:
  A slow-rolling scalar field ($Q\equiv$ Quintessence) with potential energy
$V_Q\sim (3\times 10^{-3} {\rm eV})^4$ has been proposed as the origin of
accelerating universe at present. We investigate the effective potential of $Q$
in the framework of supergravity model including the quantum corrections
induced by generic (nonrenormalizable) couplings of $Q$ to the gauge and
charged matter multiplets. It is argued that the K\"ahler potential,
superpotential and gauge kinetic functions of the underlying supergravity model
are required to be invariant under the variation of $Q$ with an extremely fine
accuracy in order to provide a working quintessence potential. Applying these
results for string or $M$-theory, we point out that the heterotic $M$-theory or
Type I string axion can be a plausible candidate for quintessence if (i) it
does not couple to the instanton number of gauge interactions not weaker than
those of the standard model and (ii) the modulus partner ${\rm Re}(Z)$ of the
periodic quintessence axion ${\rm Im}(Z)\equiv {\rm Im}(Z)+1$ has a large VEV:
${\rm Re}(Z)\sim \frac{1}{2\pi}\ln(m_{3/2}^2 M_{Planck}^2/V_Q)$. It is stressed
that such a large ${\rm Re}(Z)$ gives the gauge unification scale at around the
phenomenologically favored value $3\times 10^{16}$ GeV. To provide an
accelerating universe, the quintessence axion should be at near the top of its
effective potential at present, which requires a severe fine tuning of the
initial condition of $Q$ and $\dot{Q}$ in the early universe. We discuss a late
time inflation scenario based on the modular and CP invariance of the moduli
effective potential, yielding the required initial condition in a natural
manner if the K\"ahler metric of the quintessence axion superfield receives a
sizable nonperturbative contribution.


title: Neutrino Masses and Mixing with Non-Anomalous Abelian Flavor Symmetries

abstract:
  The experimental data on atmospheric and solar neutrinos are used to test the
framework of non-anomalous Abelian horizontal gauge symmetries with only three
light active neutrinos. We assume that the hierarchy in mass-squared splittings
is not accidental and that the small breaking parameters are not considerably
larger than 0.2. We find that the small angle MSW solution of the solar
neutrino problem can only be accommodated if the $\nu_\mu-\nu_\tau$ mass
hierarchy depends on the charges of at least three sterile neutrinos. The large
angle MSW solution can be accommodated in simpler models if $\nu_e$ and
$\nu_\mu$ form a pseudo-Dirac neutrino, but it is difficult to induce large
enough deviation from maximal mixing. The vacuum oscillation solution can be
accommodated rather simply. We conclude that it is possible to accommodate the
neutrino parameters in the framework of Abelian horizontal symmetries, but it
seems that these parameters by themselves will not provide convincing evidence
for this framework.


title: The survival probability of large rapidity gaps in a three channel model

abstract:
  The values and energy dependence for the survival probability $< \mid S\mid^2
>$ of large rapidity gaps (LRG) are calculated in a three channel model. This
model includes single and double diffractive production, as well as elastic
rescattering. It is shown that $< \mid S \mid^2 >$ decreases with increasing
energy, in line with recent results for LRG dijet production at the Tevatron.
This is in spite of the weak dependence on energy of the ratio $ (\sigma_{el}+
\sigma_{SD})/\sigma_{tot}$.


title: Heavy-Flavour Production at HERA

abstract:
  We review the theoretical and experimental status of heavy-flavour production
at HERA. The results presented include some outstanding issues in charm and
beauty photoproduction, charm production in DIS and quarkonium production.


title: A Note on W Production at HERA

abstract: We discuss W boson production at HERA including NLO QCD corrections.


title: Testing B-ball cosmology with the CMB

abstract:
  In D-term inflation models, the fluctuations of squark fields in the flat
directions give rise to isocurvature density fluctuations stored in the
Affleck-Dine condensate. After the condensate breaks up in B-balls, these can
be perturbations in the baryon number, or, in the case where the present
neutralino density comes directly from B-ball decay, perturbations in the
number of dark matter neutralinos. The latter case results in a large
enhancement of the isocurvature perturbation. In this case, the requirement
that the deviation of the adiabatic perturbations from scale invariance due to
the Affleck-Dine field is not too large imposes a lower bound on the magnitude
of the isocurvature fluctuation of about $10^{-2}$ times the adiabatic
perturbation. This should be observable by MAP and PLANCK.


title: SUSY and SUGRA Signatures at Hadron Colliders

abstract:
  After a brief introduction to SUSY I discuss the missing-p_T signature for
superparticles from R-parity conservation and the multilepton signature, which
follows from their cascade decay. The GUT and SUGRA constraints on the SUSY
mass parameters are discussed along with the resulting SUSY signals at LHC.
Finally I consider the effect of relaxing the SUGRA constraint on these
signals.


title: Heavy Quarks in DIS (Theory)

abstract:
  I review the various methods for taking account of finite quark masses in DIS
and related processes. I pay particular attention to the so-called variable
flavour number schemes (VFNS) which are designed to extrapolate smoothly from
the region near threshold of production of heavy quark pairs to the region
where the quarks become effectively massless.


title: Tests of flavor symmetry in J/psi decays

abstract:
  We use SU(3) flavor symmetry to analyze the $PP', VP$ and baryon-antibaryon
decays of $J/\psi$. Both, the SU(3)-invariant and -violating contributions are
considered. Particular attention is paid to the interference of the
electromagnetic and strong amplitudes.


title:
Flavour-symmetry correction to the ``naive'' Zweig rule for the
  scalar-meson flavour-singlet

abstract:
  We present flavour-symmetric couplings for the OZI-allowed three-meson
vertices of effective meson theories, which for the case of the two-meson
channels to which the flavour-singlet scalar meson couples, are endowed with a
correction factor with respect to the standard formula.


title: QCD and Nuclear Physics

abstract:
  The main part of this talk is a review and summary of how QCD is used in two
main areas of nuclear physics, namely in determining the quark flavor and spin
content of the proton and in ultrarelativistic heavy ion collisions. Brief
comments are made concerning effective theories in hadron physics and on the
separation of various twists in using the operator product expansion to analyze
hard processes.


title:
The phenomenology of top quark polarisation in the decay of heavy
  charged Higgs bosons at LHC and beyond

abstract:
  It has recently been shown that through the $\tau\nu$ decay mode the heavy
charged Higgs bosons $H^\pm$ can be discovered at LHC over a vast region of the
parameter space previously thought unaccessible. If the charged Higgs bosons
are discovered in this decay mode and the measurements of its mass and
$\tan\beta$ are made, it allows us to make greater use of the dominant but QCD
background contaminated $bt$ decay mode by cuts suppressing phase space for the
background. In this paper we study the top quark polarisation in the $bt$ decay
mode. When $\tan\beta$ is either moderately large ($\tan\beta\gtrsim9$) or
small ($\tan\beta\lesssim4), the correlation effects can be used as a signal of
$H^\pm$ production. We outline the analysis procedure for various decay
signatures. As an example, we demonstrate the application of our procedure to
the dominant production process $gb\to tH^-$ at LHC. The effect is clearly
observable for $H^\pm$ mass between 200 GeV and 500 GeV in both leptonic and
hadronic channels, but at 500 GeV the boost on the top quark starts to prevent
the reconstruction of invariant masses, and hence the observation of the
correlation effect, in the hadronic decay channel.


title: One-loop QCD interconnection effects in pair production of top quarks

abstract:
  We calculate the one-loop non-factorizable QCD corrections to the production
and decay of pairs of top quarks at various collider experiments. These
non-factorizable corrections interconnect the different production and decay
stages of the off-shell top-pair production processes. This in particular
affects the invariant-mass distributions of the off-shell top quarks, resulting
in a shift of the maximum of the distorted Breit-Wigner distributions. Although
the non-factorizable corrections can be large, the actual shift in the mass as
determined from the peak position of the corrected Breit-Wigner line-shape is
below $100\MeV$.


title: The Four-Jet Rate in e+e- Annihilation

abstract:
  We present an analytic expression for the four-jet rate in e+e- annihilation,
calculated using the coherent branching formalism in the Durham scheme. Our
result resums all the leading and next-to-leading kinematic logarithms to all
orders in the QCD strong coupling constant.


title: Nonperturbative Contributions to the Hot Electroweak Potential

abstract:
  The hot electroweak potential for small Higgs field values is argued to
obtain contributions from a fluctuating gauge field background leading to
confinement. The destabilization of F^2=0 and the crossover are discussed in
our phenomenological approach, also based on lattice data.


title: Collider Physics

abstract:
  These lectures are intended as a pedagogical introduction to physics at
$e^+e^-$ and hadron colliders. A selection of processes is used to illustrate
the strengths and capabilities of the different machines. The discussion
includes $W$ pair production and chargino searches at $e^+e^-$ colliders,
Drell-Yan events and the top quark search at the Tevatron, and Higgs searches
at the LHC.


title: Finding the CP-Violating Higgs Bosons at e^+e^- Colliders

abstract:
  We discuss a general two-Higgs-doublet model with CP violation in the Higgs
sector. In general, the three neutral Higgs fields of the model all mix and the
resulting physical Higgs bosons have no definite CP properties. We derive a new
sum rule relating Yukawa and Higgs-Z couplings which implies that a neutral
Higgs boson cannot escape detection at an e^+e^- collider if it is
kinematically accessible in Z+Higgs, $b\anti b+$Higgs and $t\anti t+$Higgs
production, irrespective of the mixing angles and the masses of the other
neutral Higgs bosons. We also discuss modifications of the sum rules and their
phenomenological consequences in the case when the two-doublet Higgs sector is
extended by adding one or more singlets.


title:
Addendum/Erratum for `Searching for Invisible and Almost Invisible
  Particles at $\bf e^+e^-$ Colliders' [hep-ph/9512230] and `A Non-Standard
  String/SUSY Scenario and its Phenomenological Implications' [hep-ph/9607421]

abstract:
  We correct our treatment of decays of the lightest chargino to final states
containing the lightest neutralino in the case where the chargino and
neutralino masses differ by less than 1 GeV. A brief summary of the
phenomenological implications is given.


title: Extra Dimensions and the Muon Anomalous Magnetic Moment

abstract:
  It has been proposed recently that the scale of strong gravity can be very
close to the weak scale. Dimensions of sizes anywhere from $\sim $mm to $\sim
$TeV$^{-1}$ can be populated by bulk gravitons, vector bosons and fermions. In
this paper the one-loop correction of these bulk particles to the muon magnetic
moment (MMM) are investigated. In all the scenarios considered here it is found
that the natural value for the MMM is $O(10^{-8}-10^{-9})$. One main result is
that the contribution of each Kaluza$-$Klein graviton to the MMM is remarkably
finite. The bulk graviton loop implies a limit of $\sim 400$ GeV on the scale
of strong gravity. This could be pushed up to $\sim 1-2$ TeV, even in the case
of six extra dimensions, if the BNL E821 experiment reaches an expected
sensitivity of $\sim 10^{-9}$. Limits on a bulk $B-L$ gauge boson are
interesting, but still allow for forces $10^6-10^7$ times stronger than gravity
at mm$^{-1}$ distances. The correction of a bulk right-handed neutrino to the
MMM in one recent proposal for generating small Dirac neutrino masses is
considered in the context of a two Higgs doublet model, and is found to be
close to $10^{-9}$. The contributions of all these bulk particles to the MMM
are (roughly) independent of both the total number of extra dimensions and the
dimension of the subspace occupied by the bulk states. Finally, limits on the
size of ``small'' compact dimensions gotten from the MMM and atomic parity
violation are determined and compared.