title:
Pseudoscalar Masses in the Effective Theory for Color-Flavor Locking in
  high density QCD

abstract:
  The constants of the effective action describing the massless modes in the
color-flavor-locking phase of QCD have been recently evaluated at high density.
Values of the pseudoscalar masses for nonvanishing quark masses have also been
given. The calculated values show however a puzzling feature: when $m_u=m_d=0$
and $m_s\not=0$ all the goldstones remain massless. We show that an additional
invariant is present which avoids this feature. We costruct this invariant and
discuss the emerging mass pattern for the pseudogoldstones. This provides for a
complete scheme for the pseudogoldstone masses in the color-flavor-locking
phase of QCD.


title: Neutrino Physics at the Turn of the Millenium

abstract:
  Recent solar & atmospheric nu-data strongly indicate need for physics beyond
the Standard Model. I review the ways of reconciling them in terms of 3-nu
oscillations. Though not implied by data, bi-maximal nu-mixing models emerge as
a possibility. SUSY with broken R-parity provides an attractive way to
incorporate it, opening the possibility of testing nu-anomalies at high- energy
colliders such as the LHC or at the upcoming long-baseline or nu- factory
experiments. Reconciling, in addition, the LSND hint requires a fourth, light
sterile neutrino, nus. The simplest are the most symmetric scenarios, in which
2 of the 4 neutrinos are maximally-mixed and lie at the LSND scale, while the
others are at the solar scale. The lightness of nus, the nearly maximal
atmospheric mixing, and the solar/atmospheric splittings all follow naturally
from the assumed lepton-number symmetry and its breaking. These basic schemes
can be distinguished at neutral-current-sensitive solar & atmospheric neutrino
experiments such as SNO. However underground experiments have not yet proven
neutrino masses, as there are many alternatives. For example flavour changing
interactions can play an important role in the explanation of solar and
contained atmospheric data and could be tested e.g through \mu \to e + \gamma,
\mu-e conversion in nuclei, unaccompanied by neutrino-less double beta decay.
Conversely, a short-lived numu might play a role in the explanation of the
atmospheric data. Finally, in the presence of a nus, a long-lived heavy nutau
could delay the time at which the matter and radiation contributions to the
energy density of the Universe become equal, reducing density fluctuations on
smaller scales, thus saving the standard CDM scenario, while the light nue,
numu and nus would explain the solar & atmospheric data.


title: New Representation for the 2-to-4 Gluon Vertex in High Energy QCD

abstract:
  A new representation for the two-to-four gluon vertex arising in the context
of unitarity corrections is derived which involves only BFKL kernels. We
discuss possible implications of this representation, including the possibility
of finding the NLO corrections to the vertex.


title: Photon photon scattering in a 3-3-1 model

abstract:
  We analyze the effects of a doubly charged vector bilepton as well as exotic
quarks with charge 5/3 e and -4/3 e on light by light scattering. We consider
mass values in the range 0.3--1 TeV, which would be reached at the planned
future linear colliders. It is found that such exotic particles, especially the
doubly charged vector bilepton, give raise to remarkable deviations from the
standard model cross section. The virtual effects arising from these particles
would provide an indirect test to a particular model which is based on the
SU_c(3) X SU_L(3) X U_x(1) gauge symmetry, known as the 331 model, where such
particles are a natural prediction.


title: Superconducting String Texture

abstract:
  We present a detailed analytical and numerical study of a novel type of
static, superconducting, classically stable string texture in a renormalizable
topologically trivial massive U(1) gauge model with one charged and one neutral
scalar. An upper bound on the mass of the charged scalar as well as on the
current that the string can carry are established. A preliminary unsuccesful
search for stable solutions corresponding to large superconducting loops is
also reported.


title: The Next-to-Leading BFKL Pomeron with Optimal Renormalization

abstract:
  The next-to-leading order (NLO) corrections to the BFKL equation in the BLM
optimal scale setting are briefly discussed. A striking feature of the BLM
approach is rather weak Q^2-dependence of the Pomeron intercept, which might
indicate an approximate conformal symmetry of the equation. An application of
the NLO BFKL resummation for the virtual gamma-gamma total cross section shows
a good agreement with recent L3 data at the CERN LEP2.


title: Kaluza-Klein Physics at Muon Colliders

abstract:
  We discuss the physics of Kaluza-Klein excitations of the Standard Model
gauge bosons that can be explored by a high energy muon collider in the era
after the LHC and TeV Linear Collider. We demonstrate that the muon collider is
a necessary ingredient in the unraveling the properties of such states and,
perhaps, proving their existence. The possibility of observing the resonances
associated with the excited KK graviton states of the Randall-Sundrum model is
also discussed.


title: Two-pearl Strings: Feynman's Oscillators

abstract:
  String models are designed to provide a covariant description of internal
space-time structure of relativistic particles. The string is a limiting case
of a series of massive beads like a pearl necklace. In the limit of
infinite-number of zero-mass beads, it becomes a field-theoretic string.
Another interesting limit is to keep only two pearls by eliminating all others,
resulting in a harmonic oscillator. The basic strength of the oscillator model
is its mathematical simplicity. This encourages us to construct two-pearl
strings for a covariant picture of relativistic extended particles. We achieve
this goal by transforming the oscillator model of Feynman {\it et al.} into a
representation of the Poincar\'e group. We then construct representations of
the O(3)-like little group for those oscillator states, which dictates their
internal space-time symmetry of massive particles. This simple mathematical
procedure allows us to explain what we observe in the world in terms of the
fundamental space-time symmetries, and the built-in covariance of the model
allows us to use the physics in the rest frame in order to explain what happens
in the infinite-momentum frame. It is thus possible to calculate the parton
distribution within the proton moving light-like speed in terms of the quark
wave function in its rest frame.


title:
Dijet Production at Hadron Colliders in Theories with Large Extra
  Dimensions

abstract:
  We consider the production of high invariant mass jet pairs at hadron
colliders as a test for TeV scale gravitational effects. We find that this
signal can probe effective Planck masses of about 10 TeV at the LHC with center
of mass energy of 14 TeV and 1.5 TeV at the Tevatron with center of mass energy
of 2 TeV. These results are compared to analogous scattering processes at
leptonic colliders.


title: DPMJET version II.5, code manual

abstract:
  DPMJET samples hadron-hadron, hadron-nucleus, nucleus-nucleus and
neutrino-nucleus interactions at high energies.
  The two-component Dual Parton Model is used with multiple soft chains and
multiple minijets at each elementary interaction.
  Particle production is realized by the fragmentation of colorless
parton-parton chains constructed from the quark content of the interacting
hadrons. DPMJET-II.5 includes the cascading of secondaries within the target as
well as projectile nuclei which is suppressed by the formation time concept.
  The excitation energy of the remaining target and projectile nuclei is
calculated and using this nuclear evaporation is included into the model. It is
possible to use the model up to primary energies of 10${}^{21}$ eV (per
nucleon) in the lab. frame.
  DPMJET can also be applied to neutrino nucleus collisions. It extends the
neutrino-nucleon models qel (quasi elastic neutrino interactions) and lepto
(deep inelastic neutrino nucleon collisions) to neutrino collisions on nuclear
targets.


title:
Strong Enhancement of $\epsilon'/\epsilon$ Through Final State
  Interactions

abstract:
  We quantify the important effect of strong final state interactions in the
weak $K\to2\pi$ amplitudes, using the measured $\pi$--$\pi$ phase shifts with
J=0 and $I=0,2$. The final rescattering of the two pions provides a strong
enhancement of the $\Delta I =1/2$ amplitude, which so far has been neglected
in the theoretical predictions of $\epsilon'/\epsilon$. This correction
increases the Standard Model prediction of $\epsilon'/\epsilon$ to values in
good agreement with the experimental measurements.


title:
Geometrization of vacuum condensate effects in quarkonium potential
  model

abstract:
  It is suggested the modification of traditional potential model, in which
nontrivial structure of inside-hadron vacuum condensate is simulated by
geometric properties of inside-hadron space. Confinement of quarks is ensured
by closed effective (Riemannian) space. Interquark potential represents itself
Coulomb's low in the effective space (Poisson equation). In the framework of
such approach the quarks dynamics completely is defined only by metric of the
effective space, which in turn in conformally-Euclidean case (we consider) is
defined by sole phenomenological function. Also it is supposed, that
inside-hadron vacuum is essential nonperturbative one both on large and on
small distances and this is taken into account by special parameter in the
metric of effective space. For final Schr\"odinger equation the exact
analytical solutions for nonrelativistic energy spectrum and wave functions of
quarkonium are obtained. From the basic principles of geometrized potential
model and under the perturbation theory the spin-dependent relativistic
corrections are calculated. Charmonium and bottomonium spectra are simulated.
Suggested model gives a very good fit to experimental data: accuracy of spectra
fitting makes $4.06\cdot 10^{-2}$ for charmonium and $3.28\cdot 10^{-2}$ for
bottomonium and many predictions are made. On the basis of charmonium and
bottomonium analysis conclusions about role of vacuum condensate in hadron
structure are done.


title: LEP2 4f review

abstract:
  We review some recent results and open problems on four fermion physics at
LEP2 and beyond


title: Astroparticle Physics

abstract:
  This article reviews some recent developments in Astroparticle Physics. Due
to the extension of the field only part of the results and developments can be
covered. The status of the search for Dark Matter, some recent results on
Cosmic Rays and Gamma Ray Astronomy and the status of Neutrino Astronomy are
presented.


title: QCD and Theory of Hadrons

abstract:
  Nonperturbative QCD approach is systematically derived starting from the QCD
Lagrangian. Treating spin effects as a perturbation, one obtains the universal
effective Hamiltonian describing mesons, hybrids and glueballs.
  Constituent mass of quark and gluon is calculated via string tension. The
resulting spectrum of mesons, hybrids and glueballs obtained is in good overall
agreement with lattice data and experiment.


title: Neutrino masses and mixings in SO(10)

abstract:
  Assuming a Zee-like matrix for the right-handed neutrino Majorana masses in
the see-saw mechanism, one gets maximal mixing for vacuum solar oscillations, a
very small value for $U_{e3}$ and an approximate degeneracy for the two lower
neutrino masses. The scale of right-handed neutrino Majorana masses is in good
agreement with the value expected in a SO(10) model with Pati-Salam $SU(4)\ts
SU(2)\ts SU(2)$ intermediate symmetry.


title: Hamiltonian approach to QCD_2 in the axial gauge

abstract:
  The Hamiltonian approach is developed for QCD_2 in the limit of infinite
number of colours N_C ('t Hooft model). Bosonization of the theory is performed
explicitly and the generalized Bogoliubov transformation for the composite
boson operators is introduced and used to bring the Hamiltonian into diagonal
form in the two-body sector. The resulting theory is re-formulated in terms of
effective degrees of freedom and describes the free mesons with creation and
annihilation operators commuting in the canonical way. Corrections in N_C to
the leading term in the Hamiltonian describe the interaction between mesons and
can be used to consider their decays. Chiral properties of the theory are
discussed and it is shown that the backward motion of the chiral pion
(Goldstone mode) is not suppressed and should contribute to the decays
amplitudes.


title: Rapidity Gaps in Quark and Gluon Jets - a Perturbative Approach

abstract:
  We derive the probability for rapidity gaps in a parton cascade and
investigate the dual connection with hadronic final states. A good description
of observations in e+e- annihilations is obtained by perturbative QCD
calculations in MLLA using previously determined parameters (QCD scale \Lambda
and k_T-cut-off Q_0) and applying the parton hadron duality picture. Further
predictions are derived; especially, for gaps between jets at variable
resolution we predict a strong variation of gap probabilities for small
parameters y_{cut} -> 0 in the transition from jets to hadrons. Large gaps
between partons correspond to large spatial separations of colour charges: a
colour blanching mechanism by soft processes is suggested.


title: Inclusive decays and lifetimes of doubly charmed baryons

abstract:
  We extend the analysis of weak decays of heavy hadrons to the case of doubly
charmed baryons, \Xi_{cc}^{++}, \Xi_{cc}^{+} and \Omega_{cc}^{+}. Doubly
charmed baryons are modeled as a heavy-light system containing a heavy
cc-diquark and a light quark. Such a model leads to preasymptotic effects in
semileptonic and nonleptonic decays which are essentially proportional to the
meson wave function. Very clear predictions for semileptonic branching ratios
and lifetimes of doubly charmed baryons are obtained.


title: The Next-to-Leading Dynamics of the BFKL Pomeron

abstract:
  The next-to-leading order (NLO) corrections to the BFKL equation in the BLM
optimal scale setting are briefly discussed. A striking feature of the BLM
approach is rather weak Q^2-dependence of the Pomeron intercept, which might
indicate an approximate conformal symmetry of the equation. An application of
the NLO BFKL resummation for the virtual gamma-gamma total cross section shows
a good agreement with recent L3 data at CERN LEP2 energies.


title:
Effects of Large CP-violating Soft Phases on Supersymmetric Electroweak
  Baryogenesis

abstract:
  We revisit the results of recent electroweak baryogenesis calculations and
include all allowed large CP-violating supersymmetric phases. If the phases are
large, the resulting baryon asymmetry can be considerably larger than the
observed value $n_B/s \sim 4 \times 10^{-11}$. Much of the asymmetry must
therefore be washed out, and we argue that the upper bound on the light Higgs
mass is larger than the value reported in previous work.


title: Scales and Phases of Non-Perturbative QCD

abstract:
  This is a short write-up of lectures at UK Theory Institute, Swansea UK,
Sept.99; and XVII School ``QCD: Perturbative or Non-perturbative?''
Lisbon,Portugal, Oct.99. The covered topic include (i) discussion of the scales
at which perturbative description should be changed by the non-perturbative
one. A number of various examples are considered, leading to different scales,
related to instantons or confinement effects; (ii) Instanton vacuum as an
Instanton Liquid; (iii) The phase diagram of QCD at finite temperature and
density, and especially description of a recent progress in Color
Superconductivity.


title:
Gluino Contribution to Radiative B Decays: Organization of QCD
  Corrections and Leading Order Results

abstract:
  The gluino-induced contributions to the decay b-> s gamma are investigated in
supersymmetric frameworks with generic sources of flavour violation. It is
shown that, when QCD corrections are taken into account, the relevant operator
basis of the Standard Model effective Hamiltonian gets enlarged to contain: i)
magnetic and chromomagnetic operators with a factor of alpha_s and weighted by
a quark mass m_b or m_c; ii) magnetic and chromomagnetic operators of lower
dimensionality, also containing alpha_s; iii) four-quark operators weighted by
a factor alpha_s^2. Numerical results are given, showing the effects of the
leading order QCD corrections on the inclusive branching ratio for b-> s gamma.
Constraints on supersymmetric sources of flavour violation are derived.


title: Theoretical Summary of the HADRON99 conference

abstract:
  The Constituent Quark Model has provided a remarkable description of the
experimentally observed hadron spectrum but still has no firm theoretical
basis. Attempts to provide a QCD justification discussed at Hadron99 include
QCD Sum Rules, instantons, relativistic potential models and the lattice.
Phenomenological analyses to clarify outstanding problems like the nature of
the scalar and pseudoscalar mesons and the low branching ratio for $\psi' \to
\rho-\pi$ were presented. New experimental puzzles include the observation of
$\bar p p \to \phi \pi$.


title:
Unraveling critical dynamics: The formation and evolution of topological
  textures

abstract:
  We study the formation of topological textures in a nonequilibrium phase
transition of an overdamped classical O(3) model in 2+1 dimensions. The phase
transition is triggered through an external, time-dependent effective mass,
parameterized by quench timescale \tau. When measured near the end of the
transition the texture separation and the texture width scale respectively as
\tau^(0.39 \pm 0.02) and \tau^(0.46 \pm 0.04), significantly larger than
\tau^(0.25) predicted from the Kibble-Zurek mechanism. We show that
Kibble-Zurek scaling is recovered at very early times but that by the end of
the transition the power-laws result instead from a competition between the
length scale determined at freeze-out and the ordering dynamics of a textured
system. In the context of phase ordering these results suggest that the
multiple length scales characteristic of the late-time ordering of a textured
system derive from the critical dynamics of a single nonequilibrium correlation
length. In the context of defect formation these results imply that significant
evolution of the defect network can occur before the end of the phase
transition. Therefore a quantitative understanding of the defect network at the
end of the phase transition generally requires an understanding of both
critical dynamics and the interactions among topological defects.


title: What will the first year of SNO show?

abstract:
  The ratio of the measured to the predicted standard model CC event rates in
SNO will be 0.47 if no oscillations occur. The best-fit active oscillation
predictions for the CC ratio are: 0.35-39 (MSW) and 0.38-42 (vacuum) (all for a
5 MeV energy threshold), typically about 20% less than the no-oscillation
expectation. We calculate the predicted ratios for six active and sterile
neutrino oscillation solutions allowed at 99% CL and determine the dependence
of the ratios on energy threshold. If the high-energy anomaly observed by
SuperKamiokande is due to an enhanced hep flux, MSW active solutions predict
that out of a total of 5000 CC events above 5 MeV in SNO between 49 and 54
events will be observed above 13 MeV whereas only 19 events are expected for
no-oscillations and a nominal standard hep flux.


title:
Polarization and spin correlations of top quarks at a future e+ e-
  linear collider

abstract:
  We discuss the polarization and spin correlations of top quarks produced
above threshold at a future linear collider, including QCD radiative
corrections.


title:
Electroweak Penguin Contributions to Non-Leptonic Delta F = 1 Decays at
  NNLO

abstract:
  We calculate the O(alpha_s) corrections to the Z^0-penguin and electroweak
box diagrams relevant for non-leptonic Delta F = 1 decays with F = S, B. This
calculation provides the complete O(alpha_w alpha_s) and O(alpha_w alpha_s
sin^2 theta_w m_t^2) corrections (alpha_w = alpha/sin^2 theta_w) to the Wilson
coefficients of the electroweak penguin four quark operators relevant for
non-leptonic K- and B-decays. We argue that this is the dominant part of the
next-next-to-leading (NNLO) contributions to these coefficients. Our results
allow to reduce considerably the uncertainty due to the definition of the top
quark mass present in the existing NLO calculations of non-leptonic decays. The
NNLO corrections to the coefficient of the color singlet (V-A)x(V-A)
electroweak penguin operator Q_9 relevant for B-decays are generally moderate,
amount to a few percent for the choice m_t(mu_t = m_t) and depend only weakly
on the renormalization scheme. Larger NNLO corrections with substantial scheme
dependence are found for the coefficients of the remaining electroweak penguin
operators Q_7, Q_8 and Q_10. In particular, the strong scheme dependence of the
NNLO corrections to C_8 allows to reduce considerably the scheme dependence of
C_8 (Q_8)_2 relevant for the ratio epsilon'/epsilon.


title: Dynamical Supersymmetry Breaking with Gauged U(1)_R Symmetry

abstract:
  We propose a simple model of dynamical supersymmetry breaking in the context
of minimal supergravity with gauged $U(1)_R$ symmetry. The model is based on
the gauge group $SU(2) \times U(1)_R$ with three matters. Since the $U(1)_R$
symmetry is gauged, the Fayet-Iliopoulos D-term appears due to the symmetry of
supergravity. On the other hand, the superpotential generated dynamically by
the SU(2) gauge dynamics leads to run away potential. Since the supersymmetric
vacuum condition required by the D-term potential contradicts the one required
by the superpotential, supersymmetry is broken. The supersymmetry breaking
scale is controlled by the dynamical scale of the SU(2) gauge interaction. We
can choose the parameters in our model for vanishing cosmological constant. Our
model is phenomenologically viable with the gravitino mass of order 1 TeV or 10
TeV.


title:
Electroweak and Flavor Physics in Extensions of the Standard Model with
  Large Extra Dimensions

abstract:
  We study the implications of extra dimensions of size $R\sim 1/TeV$ on
electroweak and flavor physics due to the presence of Kaluza-Klein excitations
of the SM gauge-bosons. We consider several scenarios with the SM fermions
either living in the bulk or being localized at different points of an extra
dimension. Global fits to electroweak observables provide lower bounds on 1/R,
which are generically in the 2-5 TeV range. We find, however, certain models
where the fit to electroweak observables is better than in the SM, because of
an improvement in the prediction to the weak charge Q_W. We also consider the
case of softly-broken supersymmetric theories and we find new non-decoupling
effects that put new constraints on 1/R. If quarks of different families live
in different points of the extra dimension, we find that the Kaluza-Klein modes
of the SM gluons generate (at tree level) dangerous flavor and CP-violating
interactions. The lower bounds on 1/R can increase in this case up to 5000 TeV,
disfavoring these scenarios in the context of TeV-strings.


title: $\gamma\gamma\to\pi^+\pi^-$ in the Modified Perturbative Approach

abstract:
  We investigate the transverse momentum effects in $\gamma\gamma\to\pi^+\pi^-$
at moderately large total center of mass energy $\sqrt{s}$ in the modified
perturbative approach. The calculation of the differential cross section using
different approximations shows that the inclusion of $k_\perp$ in the quark and
gluon propagators cannot lead to a considerable improvement of the theoretical
prediction.


title:
The Quark and Gluon Condensates and Low-Energy QCD Theorems in a
  Magnetic Field

abstract:
  The low-energy QCD theorems are generalized in the presence of a constant
magnetic field H. Two-loop approximation for the vacuum energy density in the
framework of the chiral perturbation theory was obtained and the quark and
gluon condensates were found as the functions of H.


title: Superheavy Supersymmetry from Scalar Mass--A Parameter Fixed Points

abstract:
  In supersymmetric models, the well-known tension between naturalness and
experimental constraints is relieved if the squarks and sleptons of the first
two generations are superheavy, with masses of order 10 TeV, and all other
superpartners are light, with masses of order 1 TeV. We show that even if all
scalar masses and trilinear A parameters are of order 10 TeV at some high
scale, a mass-squared hierarchy of order 400 may be generated dynamically
through renormalization group evolution. The required high energy relations are
consistent with grand unification, or, alternatively, may be realized in
moduli-dominated supersymmetry-breaking scenarios.


title: Hard scattering in high-energy QCD

abstract:
  I review the recent results in the field of QCD at high energy presented to
this Conference. In particular, I will concentrate on measurements of $\as$
from studies of event structures and jet rates, jet production in hadronic
collisions, and heavy quark production.


title: The gravitino abundance in supersymmetric `new' inflation models

abstract:
  We consider the abundance of gravitinos created from the vacuum fluctuation,
in a class of `new' inflation models for which global supersymmetry is a good
approximation. Immediately after inflation, gravitinos are produced, with
number density determined by equations recently presented by Kallosh et. al.
(hep-th/9907124) and Giudice et. al. (hep-ph/9907510). Unless reheating
intervenes, creation may continue, maintaining about the same number density,
until the Hubble parameter falls below the gravitino mass. In any case, the
abundance of gravitinos created from the vacuum fluctuation exceeds the
abundance from thermal collisions in a significant regime of parameter space,
leading to tighter cosmological constraints.


title:
T-violation search with very long baseline neutrino oscillation
  experiments

abstract:
  We consider possibilities of observing T-violation effects in neutrino
oscillation experiments with very long baseline (~ 10000 km) using low energy
neutrino (~ several hundreds MeV). We show that the matter effect effectively
changes only the first-second generation mixing angle, respecting solar
neutrino deficits and atmospheric neutrino anomalies. The effective mixing of
the first-second generation in the Earth grows up to maximum by resonance. This
effect enables one to search T violation in case the first-second mixing angle
is small. We discuss its implications to the observations of T-violation
effects in long baseline experiments.


title:
The New $\sigma_{tot}(\Sigma p)$ Data, the new PDG fit to hadron total
  cross sections and the TCP alternative

abstract:
  The new SELEX measurement $\sigma_{tot}(\Sigma p) = 36.96 \pm 0.65$ at P =
609 GeV/c and the new 1998 Particle-Data-Group Regge (PDG) analysis of hadron
total cross sections with an additional even-signature-exchange contribution
recall the 1975 two-component-Pomeron model (TCP), which introduced such an
additional term and predicted $\sigma_{tot}(\Sigma p) = 37.07$ mb. in 1975 as
well as fitting all the same data now fit by PDG with fewer free parameters.and
predicting $\sigma_{tot}(\Sigma p)$, (not predicted by PDG) at lower energies.
The additional contribution confuses the extraction of the Pomeron intercept
from data in the 600 GeV range and its dynamical origin is still unclear. But
its surprising systematics suggests an interesting origin.


title: Spectrum and Decays of Hadronic Atoms

abstract:
  Using non relativistic effective Lagrangian techniques, we analyze the
hadronic decay of the pi+pi- atom and the strong energy-level shift of pionic
hydrogen in the ground state. We derive general formulae for the width and
level shift, valid at next-to-leading order in isospin breaking. The result is
expressed in terms of hadronic threshold amplitudes that include
isospin-breaking effects. In order to extract isospin symmetric scattering
lengths from the data, we invoke chiral perturbation theory, that allows one to
relate the scattering lengths to the threshold amplitudes.


title: Theoretical Analysis of Static Hyperon Data for HYPERON99

abstract:
  We consider all hyperon data relevant to spin and flavor structure of
hyperons. In addition to masses and magnetic moments considered as static
properties in Hyperon99 we include also relevant data from hyperon decays and
spin structure determined from deep inelastic scattering. Any theoretical model
for the hyperons with parameters to be determined from experiment should use
input from all these data. Of particular interest are new data from $\Xi^o$
decay and the polarixation of $\Lambda's$ produced in Z^o decays and deep
inelastic scattering.


title: Bulk Gauge Fields in the Randall-Sundrum Model

abstract:
  We explore the consequences of placing the Standard Model gauge fields in the
bulk of the recently proposed localized gravity model of Randall and Sundrum.
We find that the Kaluza Klein excitations of these fields are necessarily
strongly coupled and we demonstrate that current precision electroweak data
constrain the lowest states to lie above $\simeq 23$ TeV. Taking the weak scale
to be $\sim 1$ TeV, the resulting implications on the model parameters force
the bulk curvature, $R_5$, to be larger than the higher dimensional Planck
scale, $M$, violating the consistency of the theory. In turn, to preserve
$|R_5|\lsim M^2$, the weak scale must be pushed to $\gsim 100$ TeV. Hence we
conclude that it is disfavored to place the Standard Model gauge fields in the
bulk of this model as it is presently formulated.


title: Charmless hadronic B decays and the recent CLEO data

abstract:
  In the light of recent experimental data from the CLEO Collaboration we
study, the decays of B mesons to a pair of pseudoscalar (P) mesons, and a
vector (V) meson and a pseudoscalar meson, in the framework of factorization.
In order to obtain the best fit for the recent CLEO data, we critically examine
the values of several input parameters to which the predictions are sensitive.
These input parameters are the form factors, the strange quark mass, $\xi
\equiv 1/ N_c$ (N_c is the effective number of color), the CKM matrix elements
and in particular, the weak phase $\gamma$. It is possible to give a
satisfactory account of the recent experimental results in $B \to PP$ and VP
decays, with constrained values of a \emph{single} $\xi$. We identify the decay
modes in which CP asymmetries are expected to be large.


title:
Flavor Problem, Proton Decay And Neutrino Oscillations In SUSY Models
  With Anomalous ${\cal U}(1)$

abstract:
  We discuss how realistic supersymmetric models can be constructed by
employing an anomalous ${\cal U}(1)$ flavor symmetry which also mediates
supersymmetry breaking. A judicious choice of ${\cal U}(1)$ charges enables the
first two squark families to be sufficiently heavy ($\stackrel{>}{_\sim}10$
TeV), so that flavor changing neutral currents as well as dimension five
nucleon decay are adequately suppressed. Using the SU(5) example, the charged
fermion mass hierarchies, magnitudes of the CKM matrix elements, as well as the
observed neutrino oscillations are simultaneously accommodated. We estimate the
proton lifetime to be $\tau_p\sim 10^3\cdot \tau_p[{\rm minimal} SU(5)]$, with
the decay mode $p\to K\mu $ being comparable to $p\to K\nu_{\mu, \tau}$.


title:
Resummation of QED Perturbation Series by Sequence Transformations and
  the Prediction of Perturbative Coefficients

abstract:
  We propose a method for the resummation of divergent perturbative expansions
in quantum electrodynamics and related field theories. The method is based on a
nonlinear sequence transformation and uses as input data only the numerical
values of a finite number of perturbative coefficients. The results obtained in
this way are for alternating series superior to those obtained using Pad\'{e}
approximants. The nonlinear sequence transformation fulfills an
accuracy-through-order relation and can be used to predict perturbative
coefficients. In many cases, these predictions are closer to available analytic
results than predictions obtained using the Pad\'{e} method.


title: New Topflavor Models with Seesaw Mechanism

abstract:
  New class of models are constructed in which the third family quarks, but not
leptons, experience a new SU(2) or U(1) gauge force. Anomaly cancellation
enforces the introduction of spectator quarks so that the top and bottom masses
are naturally generated via a seesaw mechanism. We find the new contributions
to the (S,T,U) parameters and Zbb vertex to be generically small. We further
analyze how the reasonable flavor mixing pattern can be generated to ensure the
top-seesaw mechanism and sufficiently suppress the flavor-changing effects for
light quarks. Collider signatures for the light Higgs boson and top quark are
also discussed.


title:
Chiral Approach to Weak Radiative Hyperon Decays and the $\Xi^0 -->
  \Lambda \gamma $ Asymmetry

abstract:
  We reanalyse the recent version of the chiral model of weak radiative hyperon
decays, proposed by Borasoy and Holstein. It is shown that predictions of the
analysed model are significantly changed when one accepts the usual
classification of $\Lambda (1405)$ as an SU(3)-singlet. In particular, for the
$\Xi ^0 \to \Lambda \gamma $ decay large negative asymmetry is obtained. This
is contrasted with the Hara's-theorem-violating approaches where this asymmetry
is large and positive.


title:
First principle quadratic and linear mass operators, quarkonium spectrum
  and Regge trajectories

abstract:
  In previous works, a squared mass operator M^2 and a more common centre of
frame Hamiltonian H_CM for the quark-antiquark system were obtained by using
the only assumption that ln W (W being the Wilson loop correlator) can be
written in QCD as the sum of its perturbative expression and an area term. We
evaluated the spectrum of these operators by neglecting all the spin-dependent
terms but for a spin-spin term. We succeeded in reproducing rather well the
entire meson spectrum and for the light-light systems we found straight Regge
trajectories with the right slope and intercepts. A first attempt to study the
contribution of the spin dependent terms has been made.


title: Theory of Nonleptonic B Decays

abstract:
  I briefly review some recent progress in the theory of nonleptonic B decays.
After introducing the operator product expansion and the relevant effective
Hamiltonian, I discuss the domain of validity and the theoretical justification
of the factorization approximation and of its generalizations. Furthermore, I
review some general parameterizations of B decay amplitudes: the "diagrammatic"
approach and the formalism based on Wick contractions in the matrix elements of
four-fermion operators.


title: Shadowing Corrections and Diffractive Production in DIS on Nuclei

abstract:
  We calculate, in the Glauber-Mueller approach, the ratio of the diffractive
dissociation cross section to the total cross section on nuclei. We observe
that shadowing corrections (SC) are significant, in the calculated $\ddt$ ratio
but they do not lead to a smooth energy dependence of the ratio for a proton
target as was observed at HERA.


title:
Light-Front Quark Model Analysis of Electroweak Decays of Pseudoscalar
  and Vector Mesons

abstract:
  We investigate the electroweak form factors and semileptonic decay rates of
pseudoscalar and vector mesons using the light-front constituent quark model.
Our method of analytic continuation in the Drell-Yan-West (q^+=q^0+q^3=0) frame
to obtain the weak form factors avoids the difficulty associated with the
contributions from the nonvalence quark-antiquark pair creation. This method
seems to provide a promising step forward to handle the exclusive processes in
the timelike region. Our calculation reveals that the zero mode contribution is
crucial to obtaining the correct values of the light-front current J^{-} in the
q^+=0 frame. Our numerical results are overall in a very good agreement with
the available exprimental data.


title: Supersymmetric Grandunification: An Update

abstract:
  Recent developments in supersymmetric unified theories are reviewed, with
particular emphasis on supersymmetric grand unification and a brief discussion
of recent ideas about extra dimensions.


title: Resummation of Singlet Parton Evolution at Small x

abstract:
  We propose an improvement of the splitting functions at small x which
overcomes the apparent problems encountered by the BFKL approach. We obtain a
stable expansion for the x-evolution function chi(M) near M=0 by including in
it a sequence of terms derived from the one- and two-loop anomalous dimension
gamma. The requirement of momentum conservation is always satisfied. The
residual ambiguity on the splitting functions is effectively parameterized in
terms of the value of lambda, which fixes the small x asymptotic behaviour
x^-lambda of the singlet parton distributions. We derive from this improved
evolution function an expansion of the splitting function which leads to good
apparent convergence, and to a description of scaling violations valid both at
large and small x.


title: Stop Decays with R-Parity Violation and the Neutrino Mass

abstract:
  The atmospheric and solar neutrino problems can be explained in a
supersymmetric scenario where R-parity is broken bilinearly. Within this
context we explore the decays of the top squark. We find that the Rp violating
decay $\tilde t_1 -> b \tau$ can easily dominate over the Rp conserving decay
$\tilde t_1 -> c \tilde\chi^0_1$ and sometimes also over the decay $\tilde t_1
-> b \tilde\chi^+_1$. We study the implications of non-universal boundary
conditions at the GUT scale.


title:
Fermion Masses and Neutrino Oscillations in SO(10) SUSY GUT with D_3 x
  U(1) Family Symmetry

abstract:
  Discrete nonabelian gauge symmetries appear to be the most advantageous
candidates for a family symmetry. We present a predictive SO(10) SUSY GUT model
with $D_3 \times U(1)$ family symmetry (D_3 is the dihedral group of order 6).
The hierarchy in fermion masses is generated by the family symmetry breaking
$D_3 \times U(1) \to Z_N \to $ nothing. This model fits the low energy data in
the charged fermion sector quite well and naturally provides large angle
$\nu_{\mu}$-$\nu_{\tau}$ mixing describing atmospheric neutrino oscillation
data and small angle $\nu_e$-$\nu_s$ mixing consistent with the small mixing
angle MSW solution to the solar neutrino data. In addition, the non-abelian
family symmetry D_3 is sufficient to suppress large flavor violations.


title: NRQCD: A Critical Review

abstract:
  In this talk I review some recent applications of NRQCD. I first discuss the
unquenched NRQCD lattice extractions of the strong coupling constant, paying
particular attention to the recent advances in reducing systematic errors. I
then discuss the progress made in testing the NRQCD/factorization formalism for
onium production. In particular, I gather the evidence, or lack thereof, for
the universality of the production matrix elements. I also discuss the
interesting question of polarized production, which is a crucial test of the
formalism. I address the viability of this theory for the J/psi system as well
as what needs to be done before we can reach any definitive conclusions.


title:
The three loop slope of the Dirac form factor and the 1S Lamb shift in
  hydrogen

abstract:
  The last unknown contribution to hydrogen energy levels at order m alpha ^7,
due to the slope of the Dirac form factor at three loops, is evaluated in a
closed analytical form. The resulting shift of the hydrogen nS energy level is
found to be 3.016/n^3 kHz. Using the QED calculations of the 1S Lamb shift, we
extract a precise value of the proton charge radius r_p=0.883 \pm 0.014 fm.


title: Diffractive parton distributions in light-cone QCD

abstract:
  We discuss recent theoretical results on diffractive deeply inelastic
scattering, focusing on the partonic picture of diffraction in configuration
space and the predictions for the beta behavior and the scaling violation.


title: Chiral dynamics of many-pion systems

abstract:
  Based on the Weinberg lagrangian or, in a new language, the lagrangian of
hidden local symmetry added with the term induced by the anomalous lagrangian
of Wess and Zumino, the dynamics of the decays rho to 4 pi and omega to 5 pi is
considered. The excitation curves of rho resonance in its decay to 4 pi are
obtained for the first time. The comparison with recent CMD-2 data is given.
The partial widths of the decays omega to 2 pi^+ 2 pi^- pi^0 and omega to pi^+
pi^- 3 pi^0 which can be measured on colliders with luminosity 10^{33}{cm
}^{-2}{s}^{-1} are evaluated for the first time.


title: Overall determination of the CKM matrix

abstract:
  We discuss the problem of theoretical uncertainties in the combination of
observables related to the CKM matrix elements and propose a statistically
sensible method for combining them. The overall fit is performed on present
data, and constraints on the matrix elements are presented as well as on
fB*sqrt(Bb). We then explore the implications of recent measurements and
developments: jpsi-KS CP asymmetry, epsilon_prime/epsilon and B -> K pi
branching fractions. Finally, we extract from the overall fit the Standard
Model expectations for the rare kaon decays K -> pi nu anti-nu.


title: Search for New Physics in the Semileptonic D_{l4} Decays, D->K \pi l \nu

abstract:
  New physics effects through the direct CP violation and the decay rate change
are investigated in the semileptonic $D_{l4}$ decays, $D^\pm\to K\pi l^\pm
\nu$, by including a scalar-exchange interaction with a complex coupling. In
the decay process, we included various excited states as intermediate states
decaying to the final hadrons, $K+\pi$, and found that among the intermediate
states only the lowest state ($K^*$) is dominant and the other higher excited
states are negligible, contrary to the $B_{l4}$ decays. We also obtained
constraints on the new complex coupling within the multi-Higgs doublet model
and the scalar leptoquark models.


title: Soft Color Fields in DIS at low x and low Q^2

abstract:
  Two complementary approaches to DIS at low $x$ and low $Q^2$ are presented.
In the first case we apply a model containig two Pomeron trajectories. In the
second case we determine the gluon density in the semiclassical treatment at
next-to-leading order. Both approaches rely on the concept of soft color
fields.


title:
Quark-antiquark potential with retardation and radiative contributions
  and the heavy quarkonium mass spectra

abstract:
  The charmonium and bottomonium mass spectra are calculated with the
systematic account of all relativistic corrections of order v^2/c^2 and the
one-loop radiative corrections. Special attention is paid to the contribution
of the retardation effects to the spin-independent part of the quark-antiquark
potential, and a general approach to accounting for retardation effects in the
long-range (confining) part of the potential is presented. A good fit to
available experimental data on the mass spectra is obtained.


title: Chiral Shielding

abstract:
  We demonstrate how a chiral soft pion theorem (SPT) shields the scalar meson
ground state isoscalar $\sigma(600-700)$ and isospinor $\kappa(800-900)$ from
detection in $a_{1}\to\pi(\pi\pi)_{\mathrm{swave}}$,
$\gamma\gamma\to2\pi^{\circ}$, $\pi^{-}p\to\pi^{-}\pi^{+}n$ and $K^{-}p\to
K^{-}\pi^{+}n$ processes. While pseudoscalar meson PVV transitions are known to
be determined by (only) quark loop diagrams, the above SPT also constrains
scalar meson SVV transitions to be governed (only) by meson loop diagrams. We
apply this latter SVV theorem to $a_{0}\to\gamma\gamma$ and
$f_{0}\to\gamma\gamma$ decays.


title: Chiral symmetry and spectrum of Euclidean Dirac operator

abstract:
  After recalling some connections between the Spontaneous Breakdown of Chiral
Symmetry (SBChS) and the spectrum of the Dirac operator for Euclidean QCD on a
torus, we use this tool to reconsider two related issues : the Zweig rule
violation in the scalar channel and the dependence of SBChS order parameters on
the number N_f of massless flavours. The latter would result into a great
variety of SBChS patterns in the (N_f,N_c) plane, which could be studied
through so-called Leutwyler-Smilga sum rules in association with lattice
computations of the Dirac spectrum.


title:
Model for Polarized and Unpolarized Parton Density Functions in the
  Nucleon

abstract:
  We present a physical model for polarized and unpolarized structure functions
and parton density functions (PDFs) of the proton and the neutron. It
reproduces the data on F_2^p(x,Q^2) for 0.00001<x<1 and 2.5<Q^2<5000 GeV^2,
F_2^p(x)-F_2^n(x), F_2^n(x)/F_2^p(x), xg(x), dbar(x)-ubar(x), d(x)/u(x), the
Gottfried sum, the fractional momentum of charged partons and the polarized
structure functions g_1^{p,n}(x), at various Q^2. We present for the first
time, proton and neutron PDFs which do not assume charge symmetry. Contrary to
the common practice, we explain polarized and unpolarized data with a single
model.


title: QCD spectral sum rules and spontaneously broken chiral symmetry

abstract:
  The gap Delta = 4 pi f_pi ~ 1.2 GeV of spontaneous chiral symmetry breaking
is introduced as a scale delineating resonance and continuum regions in the QCD
spectral sum rules for vector mesons. Basic current algebra results are easily
recovered, and accurate sum rules for the lower moments of the spectral
distributions are derived. The in-medium scaling of vector meson masses finds a
straightforward interpretation, at least in the narrow width limit.


title: Cross Section for Topcolor Z' decaying to top-antitop

abstract:
  We present a calculation of the cross section for the process p pbar -> Zt'
-> t tbar, the production of a Topcolor Z' with subsequent decay to top quark
pairs in proton anti-proton collisions at 1.8 TeV. Variations of the cross
section with varying assumptions about the model, the resonance width, the
parton distributions and the renormalization scale are presented.


title: Small-x Physics, High Parton Densities and Parton Saturation in QCD

abstract:
  Partons are defined as the quanta in a Fock space description of a hadron.
Gluon saturation is described in the Weizs\"{a}cker-Williams approximation for
a large nucleus. The elements of DGLAP and BFKL evolution are given with the
BFKL equation derived in a large-$N_c$ dipole formalism. A more general
discussion of saturation is given in terms of a dipole scattering on a nucleon
or nucleus. Possible evidence for saturation at HERA is discussed.


title:
KNO Scaling in the Neutral Pion Multiplicity Distributions for
  pi^{-}-proton interactions at 40 and 250 GeV/c

abstract:
  We analysed the binomial multiplicity moments of the neutral pions, using an
extension of the generating functional technique for detection losses. We
applied this model-independent method to the individual gamma-weights of 10000
events of pi^{-}-proton interactions at 40 GeV/c. We compared the obtained
results to those of 250 GeV/c. We used the FRITIOF and a shifted KW
distribution to describe the data.


title: Glueball spectrum and the Pomeron in the Wilson loop approach

abstract:
  Using a nonperturbative method based on asymptotic behaviour of Wilson loops
we calculate masses of glueballs and corresponding Regge-trajectories. The only
input is string tension fixed by meson Regge slope, while perturbative
contributions to spin splittings are defined by standard alpha_s values. The
masses of lowest glueball states are in a perfect agreement with lattice
results. The leading glueball trajectory which is associated with Pomeron is
discussed in details and its mixing with f and f' trajectories is taken into
account.


title: Single Production of Leptoquarks at the Tevatron

abstract:
  We study the single production of first generation leptoquarks in association
with a e+/- at the Fermilab Tevatron. We focus our attention on final states
exhibiting a e+e- pair and jets, and perform a detailed analyses of signal and
backgrounds. The single leptoquark production cross section depends on the
leptoquark Yukawa coupling to lepton-quark pairs and we show that the study of
this mode can extend considerably the leptoquark search for a large range of
these couplings. In fact, for Yukawa couplings of the electromagnetic strength,
the combined results of the Tevatron experiments can exclude the existence of
leptoquarks with masses up to 260--285 (370--425)
  GeV at the RUN I (RUN II), depending on their type.


title: Supersymmetry Breaking through Transparent Extra Dimensions

abstract:
  We propose a new framework for mediating supersymmetry breaking through an
extra dimension. It predicts positive scalar masses and solves the
supersymmetric flavor problem. Supersymmetry breaks on a ``source'' brane that
is spatially separated from a parallel brane on which the standard model matter
fields and their superpartners live. The gauge and gaugino fields propagate in
the bulk, the latter receiving a supersymmetry breaking mass from direct
couplings to the source brane. Scalar masses are suppressed at the high scale
but are generated via the renormalization group. We briefly discuss the
spectrum and collider signals for a range of compactification scales.


title: Gauge bosons in a five-dimensional theory with localized gravity

abstract:
  We consider the possibility of gauge bosons living in the recently proposed
five-dimensional theory with localized gravity. We study the mass spectrum of
the Kaluza-Klein (KK) excitations of the gauge fields and calculate their
couplings to the boundaries of the fifth dimension. We find a different
behaviour from the case of the graviton. In particular, we find that the
massless mode is not localized in the extra dimension and that the KK
excitations have sizeable couplings to the two boundaries. We also discuss
possible phenomenological implications for the case of the standard model gauge
bosons.


title:
Multiple Higgs Production and Measurement of Higgs Trilinear Couplings
  in the MSSM

abstract:
  An elementary Higgs boson, which is the remnant of the spontaneous symmetry
breaking mechanism in the Standard Model, remains one of the most elusive
particles. If a Higgs boson candidate is found at future accelerators, it
becomes necessary to determine its properties, beyond the mass, production
cross section and decay rates. The other crucial properties relate to the
self-couplings of the Higgs boson, which are necessary to reconstruct the Higgs
potential, and thereby confirm the mechanism of spontaneous symmetry breaking.
In this paper we review the question of the measurability of some of the
trilinear couplings of the neutral Higgs bosons of the Minimal Supersymmetric
Standard Model at a high-energy e+e- collider.


title:
QED radiative corrections to e+e- --> f+f- with realistic cuts at LEP
  energies and beyond

abstract:
  After 10 years of steadily increasing the experimental precision at LEP/SLC,
there is a strong demand on an update of existing programs for fermion pair
production. We present a rederivation of the O(alpha) Bremsstrahlung
corrections to e+e- --> f+f- for the semi-analytic program ZFITTER. We focus on
observables like total cross section and forward-backward asymmetry in the
leptonic case with combined cuts on acollinearity angle, acceptance angle, and
minimal energy of the fermions. The outcome of our analysis is a shift of the
predictions by ZFITTER at LEP 1 energies off-resonance of a few per mil while
at the Z resonance numerical changes can be neglected. Thus we obtain for cross
sections and asymmetries at LEP 1 a level of agreement with other programs of
better than per mil, like for the kinematically simpler s' cut option. A
preliminary analysis of ZFITTER, TOPAZ0, and other codes at LEP 2 energies
showing deviations of several per cent with acollinearity cuts enforce a future
examination of higher order effects with different cuts. The predictions by
LEP/SLC data, however, are not affected within the experimental errors.


title: The phi to pi+ pi- decay within a chiral unitary approach

abstract:
  Starting from the Chiral Perturbation Theory Lagrangian, but keeping
different masses for the charged and neutral mesons, and using a previously
developed non-perturbative unitary scheme that generates the lightest
meson-meson resonances, we construct K Kbar to K Kbar and K Kbar to pi+ pi- in
the vector channel. This allows us to obtain the kaon-loop contribution to the
phi-rho mixing and study the phi to pi+pi- decay. The dominant contribution to
this decay comes from the phi to gamma to pi+pi- process. However, there can be
large interferences with the subdominant contributions coming from phi-rho and
phi-omega mixing, or of these two contributions among themselves. As a
consequence, a reliable measurement of phi to pi+pi- decay could be used to
differentiate between some phi-omega mixing scenarios proposed in the
literature.


title: Bounds on effective Majorana neutrino masses at HERA

abstract:
  The lepton-number violating process e p \to nu_e l l' X mediated by Majorana
neutrinos is studied for the HERA collider for (l l') = (e tau), (mu tau), (mu
mu) and (tau tau). Only the muonic decay of the tau is considered. The direct
limit on the effective muon Majorana mass, <m_{mu mu}> is improved
significantly to 4.0 times 10^3 GeV and for the first time direct limits on the
analogous effective masses connected with the tau sector are given, namely 4.2
times 10^3 GeV for <m_{e tau}>, 4.4 times 10^3 GeV for <m_{mu tau}> and 2.0
times 10^4 GeV for <m_{tau tau}>. We find that a more general analysis for an
upgraded HERA could improve this values by a factor of up to 40, yet still
being orders of magnitude worse than indirect limits.


title: Perturbative QCD and Power Corrections

abstract:
  A short review is given of the present status of the studies of genuine
confinement effects in multiple hadron production in hard processes


title: Dirac operator spectral density and low energy sum rules

abstract:
  The spectral density of euclidean Dirac operator is investigated in partially
quenched QCD with arbitrary quark masses. A representation of scalar and
pseudoscalar correlators in terms of the spectral density is discussed. The
spectral density, obtained from the partially quenched chiral perturbation
theory is shown to be compatible with low energy sum rules, obtained earlier.


title: (Field) Symmetrization Selection Rules

abstract:
  QCD and QED exhibit an infinite set of three-point Green's functions that
contain only OZI rule violating contributions, and (for QCD) are subleading in
the large N_c expansion. The Green's functions describe the ``decay'' of a
J^{PC}={1,3,5 ...}^{-+} exotic hybrid meson current to two J=0 (hybrid) meson
currents with identical P and C. We prove that the QCD amplitude for a neutral
hybrid {1,3,5 ...}^{-+} exotic current to create eta pi0 only comes from OZI
rule violating contributions under certain conditions, and is subleading in
N_c.


title: Thermal and Non-Thermal Production of Gravitinos in the Early Universe

abstract:
  The excessive production of gravitinos in the early universe destroys the
successful predictions of nucleosynthesis. The thermal generation of gravitinos
after inflation leads to the bound on the reheating temperature, T_{RH}< 10^9
GeV. However, it has been recently realized that the non-thermal generation of
gravitinos in the early universe can be extremely efficient and overcome the
thermal production by several orders of magnitude, leading to much tighter
constraints on the reheating temperature. In this paper, we first investigate
some aspects of the thermal production of gravitinos, taking into account that
in fact reheating is not instantaneous and inflation is likely to be followed
by a prolonged stage of coherent oscillations of the inflaton field. We then
proceed by further investigating the non-thermal generation of gravitinos,
providing the necessary tools to study this process in a generic time-dependent
background with any number of superfields. We also present the first numerical
results regarding the non-thermal generation of gravitinos in particular
supersymmetric models.


title:
The non-equilibrium distribution function of particles and
  anti-particles created in strong fields

abstract:
  We investigate the quantum Vlasov equation with a source term describing the
spontaneous particle creation in strong fields. The back-reaction problem is
treated by solving this kinetic equation together with the Maxwell equation
which determines the induced time-dependent electric field in the system. The
evolution of distribution functions for bosons and fermions is studied
numerically. We found that the system shows a regular dynamic behavior if the
back-reaction is neglected. But if the back-reaction is included, it is not the
case and some stochastic features are clearly revealed in the non-equilibrium
distribution function..


title: Gluino-Mediated Rare B Decays

abstract:
  We discuss the gluino-induced contribution to rare B decays in supersymmetric
frameworks with generic sources of flavour change.


title: Relaxation of the cosmological constant at inflation?

abstract:
  We suggest that the cosmological constant has been relaxed to its present,
very small value during the inflationary stage of the evolution of the
Universe. This requires relatively low scale, very long duration and
unconventional source of inflation. We present a concrete mechanism of the
cosmological constant relaxation at the inflationary epoch.


title:
Statistical Bootstrap analysis of S+Ag interaction at 200AGeV: Evidence
  of a phase beyond the hadronic one?

abstract:
  A generalized Strangeness-incorporating Statistical Bootstrap Model (SSBM) is
constructed so as to include indepedent fugacities for up and down quarks. Such
an extension is crucial for the confrontation of multiparticle data emerging
from heavy ion collisions, wherein isospin symmetry is not satisfied. Two
constraints, in addition to the presence of a critical surface which sets the
boundaries of the hadronic world, enter the extended model. An analysis
pertaining to produced particle multiplicities and ratios is performed for the
S+Ag interaction at 200 GeV/nucleon. The resulting evaluation, concerning the
location of the source of the produced system, is slightly in favor the source
being outside the hadronic domain.


title:
Introduction to Supersymmetry: Astrophysical and Phenomenological
  Constraints

abstract:
  These lectures contain an introduction to supersymmetric theories and the
minimal supersymmetric standard model. Phenomenological and cosmological
consequences of supersymmetry are also discussed.


title:
A New Estimate of $B \to (\rho, \omega)+ \gamma$ In The Light-Cone QCD
  Sum Rule

abstract:
  We propose a new estimate of the process $B \to (\rho, \omega)+ \gamma$ by
using the light-cone QCD sum rule. The aim is to choose the chiral quark
current operators in order to eliminate the uncertainty arising from the
chiral-even operators in the correlator. In the case of neglecting the
corrections from $\rho$-meson mass, the sum rules for form factors are
obtained, which are valid to the twist-three accuracy. The resulting branching
ratios are consistent with the experimental data.


title: Dispersive calculation of B_7^{3/2} and B_8^{3/2} in the chiral limit

abstract:
  We show how the isospin vector and axialvector current spectral functions
rho_V and rho_A can be used to determine in leading chiral order the low energy
constants B_7^{3/2} and B_8^{3/2}. This is accomplished by matching the
Operator Product Expansion to the dispersive analysis of vacuum polarization
functions. The data for the evaluation of these dispersive integrals has been
recently enhanced by the ALEPH measurement of spectral functions in tau decay,
and we update our previous phenomenological determination. Our calculation
yields in the NDR renormalization scheme and at renormalization scale mu = 2
GeV the values B_7^{3/2} = 0.55 +- 0.07 +- 0.10 and B_8^{3/2} = 1.11 +- 0.16 +-
0.23 for the quark mass values m_s + m = 0.1 GeV.


title: The Twofold Way, a Short Disquisition of LEP Physics

abstract:
  A condensed survey of various aspects of LEP 1 physics is presented with a
critical examination of the ingredients that are available for theoretical
predictions. A prototype of comparisons for 2f calculations can be found in
hep-ph/9902452.


title:
Asymptotic structure of perturbative series for $\tau$ lepton decay
  observables: $m_s^2$ corrections

abstract:
  In a previous paper we performed an analysis of asymptotic structure of
perturbation theory series for semileptonic $\tau$-lepton decays in massless
limit. We extend our analysis to the Cabibbo suppressed $\Delta S=1$ decay
modes of the $\tau$ lepton. In particular we address the problem of $m_s^2$
corrections to theoretical formulas. The properties of the asymptotic behavior
of the finite order perturbation theory series for the coefficient functions of
the $m_s^2$ corrections are studied.


title:
Upper and lower bounds of the lightest CP-even Higgs boson in the
  two-Higgs-doublet model

abstract:
  By imposing validity of the perturbation and stability of vacuum up to an
energy scale $\Lambda$ ($\leq 10^{19}$ GeV), we evaluate mass bounds of the
lightest CP-even Higgs-boson mass ($m_h$) in the two-Higgs-doublet model (2HDM)
with a softly-broken discrete symmetry. The most general bounds are obtained as
a function of $\Lambda$ vering all the free parameters under the experimental
constraint from the $rho$ parameter and the b \to s \gamma$ results. We find
that, while the upper bound is almost the same as in the SM, the lower bound is
significantly reduced. In the decoupling regime where the model behaves like
the SM at low energy, the lower bound is given, for example, by about 100 GeV
for $\Lambda = 10^{19}$ GeV and $m_t = 175$ GeV, which is smaller by about 40
GeV than the corresponding lower bound in the SM. In general case, the $m_h$ is
no longer bounded from below by these conditions. If we consider the
experimental $b \to s \gamma$ constraint, small $m_h$ are excluded in Model II
of the 2HDM.


title: Spin effects in two-particle hadronic decays of B_c mesons

abstract:
  We consider spin effects in two-particle hadronic decays of B_c and B_c^*
mesons into J/psi plus \rho(\pi) in the frame work of hard gluon exchange
model. It is shown that polarization of the J/psi meson is very different in
decays of B_c and B_c^* mesons as well as their decay widths into J/psi plus
\rho(\pi).


title: Large Right Handed Rotations, Neutrino Oscillations and Proton Decay

abstract:
  Right Handed (RH) rotations are not observable in the standard model (SM).
The freedom is used to give the phenomenologically correct mass matrices all
kind of different forms and this is one of the reasons for the proliferation of
models for the fermionic masses. The SM must be however extended and in most
extensions, RH currents appear at higher energy scales. At those energies the
RH rotations are not irrelevant any more, they can affect neutrino
oscillations, proton decay, baryon assymetry, R-parity violating interactions
etc. We study possible implications of large RH mixing in GUTs. Those are
interesting not only because large mixing induce large effects. They are
intimately related to large lepton mixing in GUTs, via a relation between LH
mixing of the leptons and the RH ones of the d-quarks ,(``$d - \ell$ duality'')
and can change considerably the branching ratios of proton decay.
  Observation of proton decay channels as well as neutrino oscillations will
teach us about RH rotations and will reduce, therefore, considerably the
freedom in the fermionic mass matrices. Some interesting examples are studied
in detail. In particular a new $E_6$ model which realizes naturally a $d$ -
$\ell$ duality by mixing with exotic $E_6$ fermions.


title: Baryogenesis through leptogenesis

abstract:
  Baryogenesis by heavy-neutrino decay and sphaleron reprocessing of both
baryon and lepton number is reconsidered, paying special attention to the
flavour structure of the general evolution equations and developing an
approximate but sufficiently accurate analytic solution to the prototype
evolution equation. Two different models of neutrino masses are examined, based
on an Abelian U(1) or a non-Abelian U(2) family symmetry. We show that a
consistent picture of baryogenesis can emerge in both cases, although with
significant differences.


title: Universality of 1/Q corrections revisited

abstract:
  We provide an exact analytical calculation at the two-loop level in the
abelian limit of the leading power correction for the C parameter in e+e-
annihilation. We compare our results to the numerical value obtained employing
the soft approximation, the abelian part of the Milan factor. We demonstrate
that a simple proportionality holds between the leading power corrections to
the C parameter and to the longitudinal cross section in the soft region, and
we verify that this proportionality holds for the full two-loop abelian
contribution computed here. We comment on the possibility of extending this
technique to other event shape variables and distributions, as well as to the
non-abelian contributions.


title: Neutral Higgs Sector of the MSSM without $R_p$

abstract:
  We analyse the neutral scalar sector of the MSSM without R-parity. Our
analysis is performed for a one-generation model in terms of
``basis-independent'' parameters, and includes one-loop corrections due to
large yukawa couplings. We concentrate on the consequences of large $R_p$
violating masses in the soft sector, which mix the Higgses with the sleptons,
because these are only constrained by their one-loop contributions to neutrino
masses. We focus on the effect of $R_p$-violation on the Higgs mass and
branching ratios. We find that the experimental lower bound on the lightest
CP-even Higgs in this model can be lower than in the MSSM.


title: PHACT : Helicity amplitudes for present and future colliders

abstract:
  Helicity amplitudes calculations with the program PHACT are explained. Some
examples of their application in WPHACT and SIXPHACT MC's are given.


title: Quark-Antiquark Bound States in the Relativistic Spectator Formalism

abstract:
  The quark-antiquark bound states are discussed using the relativistic
spectator (Gross) equations. A relativistic covariant framework for analyzing
confined bound states is developed. The relativistic linear potential developed
in an earlier work is proven to give vanishing meson$\to$ $q+\bar{q}$ decay
amplitudes, as required by confinement. The regularization of the singularities
in the linear potential that are associated with nonzero energy transfers (i.e.
$q^2=0,q^{\mu}\neq0$) is improved. Quark mass functions that build chiral
symmetry into the theory and explain the connection between the current quark
and constituent quark masses are introduced. The formalism is applied to the
description of pions and kaons with reasonable results.


title:
Pion-nucleon scattering and the nucleon sigma term in an extended sigma
  model

abstract:
  A modified linear sigma model that allows for $g_A = 1.26$ by addition of
vector and pseudovector $\pi N$ coupling terms was discussed by Bjorken and
Nauenberg and by Lee. In this extended linear sigma model the elastic $\pi $N
scattering amplitudes satisfy the relevant chiral low-energy theorems, such as
the Weinberg-Tomozawa relation for the isovector scattering length and in some
cases Adler's "consistency condition". The agreement of the isospin symmetric
$\pi N$ scattering length with experiment is substantially improved in this
extended sigma model as compared with the original one. We show that the
nucleon sigma term ($\Sigma_N$) in the linear- and the extended sigma models
with three different kinds of chiral symmetry breaking terms are identical.
Within the tree approximation the formal operator expression for the $\Sigma_N$
term and the value extracted from the $\pi N$ scattering matrix coincide. Large
values of $\Sigma_N$ are easily obtained without any $s\bar s$ content of the
nucleon. Using chiral rotations the Lagrangian of this extended sigma model
reproduces the lowest-order $\pi N$ chiral perturbation theory Lagrangian.


title: CP Violation In and Beyond the Standard Model

abstract:
  The special features of CP violation in the Standard Model are presented. The
significance of measuring CP violation in B, K and D decays is explained. The
predictions of the Standard Model for CP asymmetries in B decays are analyzed
in detail. Then, four frameworks of new physics are reviewed: (i) Supersymmetry
provides an excellent demonstration of the power of CP violation as a probe of
new physics. (ii) Left-right symmetric models are discussed as an example of an
extension of the gauge sector. CP violation suggests that the scale of LRS
breaking is low. (iii) The variety of extensions of the scalar sector are
presented and their unique CP violating signatures are emphasized. (iv)
Vector-like down quarks are presented as an example of an extension of the
fermion sector. Their implications for CP asymmetries in B decays are highly
interesting.


title: $x_F$ Dependence of Drell-Yan Transverse Moemtum Broadening

abstract:
  We analyze $x_F$ dependence of Drell-Yan transverse momentum broadening in
hadron-nucleus collisions. In terms of generalized factorization theorem, we
show that the $x_F$ dependence of transverse momentum broadening, $ \Delta <
q_T^2 > (x_F) $, can be calculated in perturbative QCD. We demonstrate that
$\Delta < q_T^2 > (x_F)$ is a good observable for studying the effects of
initial-state multiple scattering and extracting quark-gluon correlation
functions.


title: Gaugino Mediated Supersymmetry Breaking

abstract:
  We consider supersymmetric theories where the standard-model quark and lepton
fields are localized on a "3-brane" in extra dimensions, while the gauge and
Higgs fields propagate in the bulk. If supersymmetry is broken on another
3-brane, supersymmetry breaking is communicated to gauge and Higgs fields by
direct higher-dimension interactions, and to quark and lepton fields via
standard-model loops. We show that this gives rise to a realistic and
predictive model for supersymmetry breaking. The size of the extra dimensions
is required to be of order 10-100 times larger than fundamental scale (e.g. the
string scale). The spectrum is similar to (but distinguishable from) the
predictions of "no-scale" models. Flavor-changing neutral currents are
naturally suppressed. The \mu term can be generated by the Giudice-Masiero
mechanism. The supersymmetric CP problem is naturally solved if CP violation
occurs only on the observable sector 3-brane. These are the simplest models in
the literature that solve all supersymmetric naturalness problems.


title: Mass Generation for an Ultralight Axion

abstract:
  If a global chiral symmetry is explicitly broken by anomalies in nonabelian
gauge theories, a pseudo Nambu-Goldstone boson (axion) associated with a
spontaneous breakdown of such a global symmetry acquires a mass through
nonperturbative instanton effects. We calculate the axion mass assuming a
supersymmetric SU(2) gauge theory and show that the axion obtains an extremely
small mass when the SU(2) gauge symmetry is broken down at very high energy,
say at the Planck scale. We identify the axion with a hypothetical ultralight
boson field proposed to account for a small but nonzero cosmological constant
suggested from recent cosmological observations.


title: Covariant Perturbation Theory of Non-Abelian Kinetic Theory

abstract:
  A double perturbation idea is presented in framework of the quark-gluon
plasma kinetic theory. A solvable set of equations from the 'double
perturbation' is derived and the equations are showed to be gauge-independent.
The formalism of Landau damping rate for the plasmon at zero momentum is given
and discussed.


title:
Relaxation from color Compton Scattering of Plasmons in A Collisionless
  Quark-Gluon Plasma

abstract:
  Non-Abelian kinetic effects are taken into account for the study of the
relaxation of collective motion in a quark-gluon plasma(QGP). An explicit
Compton scattering is considered to calculate the relaxation time.
  It is shown that the new non-Abelian relaxation has a physical mechanism from
the non-linear dynamics and the meaning of the relaxation is discussed.


title:
Neutrino Masses in the Supersymmetric Standard Model with Right-Handed
  Neutrinos and Spontaneous R-Parity Violation

abstract:
  We propose an extension of the supersymmetric standard model with
right-handed neutrinos and a singlet Higgs field, and study the neutrino masses
in this model. The Majorana masses for the right-handed neutrinos are generated
around the supersymmetry breaking scale through the vacuum expectation value of
the singlet Higgs field. This model may induce spontaneous R-parity violation
via the vacuum expectation value of the right-handed sneutrino. In the case,
the effective theory is similar to a bilinear R-parity violating model. There
are two sources for the neutrino masses: one is this bilinear R-parity breaking
effect, and the other is the ordinary seesaw effect between left- and
right-handed neutrinos. Combining these two effects, the hierarchical neutrino
mass pattern arises even when the neutrino Yukawa matrices are not
hierarchical. We acquire appropriate masses and mixings to explain both the
solar and atmospheric neutrino oscillations.


title: One kind of spinor techniques for massive fermions

abstract:
  In the work we have considered the reduction techniques matrix element of the
reaction interaction of elementary particles for massive fermions to spinor
products . The our procedure is not more complex than CALCUL spinor techniques
for massless fermions. It is relatively simple and leads to basic spinor
products with any polarizationod fermions. Also obtained spinor Chisholm
identities for massive fermions.


title: The $\mu$-Parameter of Supersymmetry

abstract:
  The Higgsino mass, or equivalently the $\mu$-parameter, plays an essential
role in determining the phenomenology of any supersymmetric model.
Particularly, the size of the supersymmetry conserving mu-parameter must be
correlated with the size of the soft supersymmetry breaking parameters. The
source of this correlation in the underlying ultra-violet theory is one of the
mysteries of supersymmetry model building. The puzzle and the various
possibilities for its resolution are reviewed, stressing both phenomenological
and theoretical aspects. New proposals in the context of supergravity and
gauge-mediation frameworks for the soft supersymmetry breaking parameters are
examined in some detail.


title:
Muon's Behaviors under Bremsstrahlung with both the LPM effect and the
  Ter-Mikaelian effect and Direct Pair Production with the LPM effect

abstract:
  Differential and integral cross sections of the muon are calculated in the
materials: water, standard rock, iron and lead with and without the LPM effect.
The corresponding cross sections are also calculated with dielectric supression
effect (Ter-Mikaelian effect), in addition to the LPM effect. To demonstrate
the importance of the LPM effect in the bremsstrahlung process, depth intensity
relation of muon, energy spectrum, range distribution and survival probability
are calculated taking into account bremsstrahlung spectrum.


title: THE CKMT Model and the Theoretical Description of the Caldwell-plot

abstract:
  The CKMT model for the nucleon structure function F_2 is in good agreement
with the HERA data at low and moderate Q^2. The fit to the same data obtained
with a modified version of the model in which a logarithmic dependence on Q^2
has been included is also discussed. Finally, we show how the parametrization
of the CKMT model for the nucleon structure function F_2 describes the HERA
data when presented in the Caldwell-plot as the behavior of the logarithmic
slopes of F_2 vs x and Q^2.


title: Bottomonium Production at the Tevatron and the LHC

abstract:
  Inclusive bottomonium hadroproduction at the Tevatron is firstly examined in
a Monte Carlo framework with the colour-octet mechanism implemented in the
event generation. We extract some NRQCD colour-octet matrix elements relevant
for $\Upsilon(1S)$ hadroproduction. Remarkably we find a quite small
contribution (compatible with zero) from feeddown of $\chi_{bJ}$ states
produced through the colour-octet mechanism: $\Upsilon(1S)$ indirect production
via $\chi_{bJ}$ decays should be mainly ascribed to the colour-singlet model.
Finally we extrapolate to LHC energies to predict prompt $\Upsilon(1S)$
production rates.


title: Gamma Ray Bursts via emission of axion-like particles

abstract:
  The Pseudo-Goldstone Boson (PGB) emission could provide a very efficient
mechanism for explaining the cosmic Gamma Ray Bursts (GRBs). The PGBs could be
produced during the merging of two compact objects like two neutron stars or
neutron star - black hole, and then decay into electron-positron pairs and
photons at distances ~ 100-1000 km. In this way, a huge energy (up to more than
10^{54} erg) can be deposited into the outer space with low baryon density in
the form of ultrarelativistic e^+e^- plasma, the so called fireball, which
originates the observed gamma-ray bursts. The needed ranges for the PGB
parameters are: mass of order MeV, coupling to nucleons g_{aN} ~ few x 10^{-6}
and to electrons g_{ae} ~ few x 10^{-9}. Interestingly enough, the range for
coupling constants correspond to that of the invisible axion with the
Peccei-Quinn symmetry breaking scale V ~ few x 10^5 GeV, but the mass of the
PGB is many orders of magnitude larger than what such a scale would demand to
an axion. Neither present experimental data nor astrophysical and cosmological
arguments can exclude such an ultramassive axion, however the relevant
parameters' window is within the reach of future experiments. Another exciting
point is that our mechanism could explain the association of some GRBs with
supernovae type Ib/c, as far as their progenitor stars have a radius ~ 10^4 km.
And finally, it also could help the supernova type II explosion: PGBs emitted
from the core of the collapsing star and decaying in the outer shells would
deposit a kinetic energy of the order of 10^{51} erg. In this way, emission of
such an axion-like particle could provide an unique theoretical base for
understanding the gamma ray bursts and supernova explosions.


title: Recent Advances in Odderon Physics

abstract:
  We present in this talk the phenomenological and theoretical advances in
Odderon physics which occured since the last EDS Blois Workshop (Seoul, 1997).


title: Simulations of Top Production and Decay at the Linear Collider

abstract:
  We review the present status of simulations of top production and decay in
the HERWIG event generator. We show the phenomenological impact of the
recently-implemented matrix-element corrections to top decays for e+e-
collisions at 360 GeV and discuss possible further improvements for studies of
future experiments at the Linear Collider.


title: B Decays in the Upsilon Expansion

abstract:
  Theoretical predictions for B decay rates are rewritten in terms of the
Upsilon meson mass instead of the b quark mass, using a modified perturbation
expansion. The theoretical consistency is shown both at low and high orders.
This method improves the behavior of the perturbation series for inclusive and
exclusive decay rates, and the largest theoretical error in the predictions
coming from the uncertainty in the quark mass is eliminated. Applications to
the determination of CKM matrix elements, moments of inclusive decay
distributions, and the B -> X_s \gamma photon spectrum are discussed.


title: CP violation as a probe of flavor origin in Supersymmetry

abstract:
  We address the question of the relation between supersymmetry breaking and
the origin of flavor in the context of CP violating phenomena. We prove that,
in the absence of the Cabibbo-Kobayashi-Maskawa phase, a general Minimal
Supersymmetric Standard Model with all possible phases in the soft-breaking
terms, but no new flavor structure beyond the usual Yukawa matrices, can never
give a sizeable contribution to $\epsilon_K$, $\epsilon^\prime/\epsilon$ or
hadronic $B^0$ CP asymmetries. Observation of supersymmetric contributions to
CP asymmetries in B decays would hint at a non-flavor blind mechanism of
supersymmetry breaking.


title: Observables in the Decays of B to Two Vector Mesons

abstract:
  In general there are nine observables in the decay of a B meson to two vector
mesons defined in terms of polarization correlations of these mesons. Only six
of these can be detected via the subsequent decay angular distributions because
of parity conservation in those decays. The remaining three require the
measurement of the spin polarization of one of the decay products.


title: HadAtom99

abstract:
  These are the proceedings of the workshop "HadAtom99", held at the Institut
fuer Theoretische Physik, Universitaet Bern, October 14-15, 1999. The main
topics discussed at the workshop were the physics of hadronic atoms and in this
context recent results from Chiral Perturbation Theory. Included here are the
program, the list of participants and a short summary provided by the speakers.


title:
A full Next to Leading Order study of direct photon pair production in
  hadronic collisions

abstract:
  We discuss the production of photon pairs in hadronic collisions, from fixed
target to LHC energies. The study which follows is based on a QCD calculation
at full next-to-leading order accuracy, including single and double
fragmentation contributions, and implemented in the form of a general purpose
computer program of "partonic event generator" type. To illustrate the
possibilities of this code, we present the comparison with observables measured
by the WA70 and D0 collaborations, and some predictions for the irreducible
background to the search of Higgs bosons at LHC in the channel $h \to \gamma
\gamma$. We also discuss theoretical scale uncertainties for these predictions,
and examine several infrared sensitive situations which deserve further study.


title: Neutrino Mass Anarchy

abstract:
  What is the form of the neutrino mass matrix which governs the oscillations
of the atmospheric and solar neutrinos? Features of the data have led to a
dominant viewpoint where the mass matrix has an ordered, regulated pattern,
perhaps dictated by a flavor symmetry. We challenge this viewpoint, and
demonstrate that the data are well accounted for by a neutrino mass matrix
which appears to have random entries.


title:
Reduction formalism for dimensionally regulated one-loop N-point
  integrals

abstract:
  We consider one-loop scalar and tensor integrals with an arbitrary number of
external legs relevant for multi-parton processes in massless theories. We
present a procedure to reduce N-point scalar functions with generic
4-dimensional external momenta to box integrals in (4-2\epsilon) dimensions. We
derive a formula valid for arbitrary N and give an explicit expression for N=6.
  Further a tensor reduction method for N-point tensor integrals is presented.
We prove that generically higher dimensional integrals contribute only to order
\epsilon for N>=5. The tensor reduction can be solved iteratively such that any
tensor integral is expressible in terms of scalar integrals. Explicit formulas
are given up to N=6.


title:
Optimal polarized observables for model-independent new physics searches
  at the linear collider

abstract:
  We discuss the sensitivity to four-fermion contact interactions of the
process of fermion-pair production at the e^+ - e^- Linear Collider (LC), with
E_{CM}=0.5 TeV and longitudinally polarized electron beam. The analysis is
based on polarized integrated cross sections with optimal cuts. Beam
polarization and optimization are shown to have a crucial role in the
derivation of model-independent constraints on the new interactions from the
data.


title:
A Direct Measurement of tan(beta): e+e- -> bb -> bbA at a Future e+e-
  Linear Collider

abstract:
  The experimental sensitivity of the reaction e+e- -> bb -> bbA has been
studied with a full-statistics background simulation for sqrt(s) = 500 GeV and
L = 500 fb-1. The simulation is based on a fast and realistic simulation of a
TESLA detector. For the first time this reaction has been analysed for a future
linear collider and we show that a signal could be observed. A significant
signal over background is achieved by the application of an Iterative
Discriminant Analysis (IDA). For a signal production cross section of only 2
fb, which is expected for a Higgs boson mass of 100 GeV and tan(beta) = 50, we
achieve 100 signal over 100 background events, and obtain for a tan(beta)
measurement: Delta(tan(beta)) / tan(beta) = 0.07. This measurement requires a
high-luminosity future collider as proposed in the TESLA project.


title: Study of Scalar Top Quarks at a Future e+e- Linear Collider

abstract:
  The scalar top discovery potential has been studied with a full-statistics
background simulation for sqrt(s) = 500 GeV and L = 500 fb-1. The simulation is
based on a fast and realistic simulation of a TESLA detector. The large
simulated data sample allowed the application of an Iterative Discriminant
Analysis (IDA) which led to a significantly higher sensitivity than in previous
studies. The effects of beam polarization on signal efficiency and individual
background channels are studied using separate optimization with the IDA for
both polarization states. The beam polarization is very important to measure
the scalar top mixing angle and to determine its mass. Simulating a 180 GeV
scalar top at minimum production cross section, we obtain Delta(m) = 1 GeV and
Delta(cos(theta)) = 0.009.


title:
QED radiative correction to spin-density matrix elements in exclusive
  vector meson production

abstract:
  QED radiative effects are considered in the case of measurement of
spin-density matrix elements of diffractive $\rho$-meson electroproduction.
Large radiative correction for $r^5_{00}$ is found in the kinematics of
collider experiments at HERA.


title: Flavour Physics: the questions, the clues and the challenges

abstract:
  Flavour physics addresses some of the questions for which the Standard Model
does not provide a satisfactory and complete answer: the origin of the
replication of the fundamental constituents and of their mass hierarchy. This
paper reviews some of the theoretical approaches and the experimental
strategies that can lead us to a more complete picture. Results included in
this review are |V_{cb}|= 0.0382 +/- 0.0032, |V_{ub}/V_{cb}|=0.085 +/- 0.023
and a preliminary measurement of the branching fraction of B -> pi^+ pi ^- =
(0.47 ({+0.18}-{-0.15}) +/- 0.06) x 10^{-5}.}


title: Theory of rare B meson decays

abstract:
  I review the NLO QCD calculations of the branching ratio for B--> X_s gamma
in the SM. Including the leading electromagnetic corrections, one obtaines
BR(B-> X_s gamma)=(3.32 +- 0.30)*10^{-4}. Confronting theory with the newest
data, an updated value for |V_{ts}| is obtained: |V_{ts}|=0.037 +- 0.007.
Theoretical progress on the photon energy spectrum is also discussed. The
inclusive FCNC semileptonic decays in the SM are briefly summarized.
Furthermore, B--> X_s gamma is considered in 2HDMs and in different SUSY
scenarios. QCD corrections are shown to be crucial.


title:
Light Sterile Neutrino from extra dimensions and Four-Neutrino Solutions
  to Neutrino Anomalies

abstract:
  We propose a four-neutrino model which can reconcile the existing data coming
from underground experiments in terms of neutrino oscillations, together with
the hint from the LSND experiment and a possible neutrino contribution to the
hot dark matter of the Universe. It applies the idea that extra compact
dimensions, probed only by gravity and possibly gauge-singlet fields, can lower
the fundamental scales such as the Planck, string or unification scales. Our
fourth light neutrino $\nu_s$ ($s$ for sterile) is identified with the zero
mode of the Kaluza-Klein states. To first approximation \nu_sterile combines
with the nu_mu in order to form a Dirac neutrino with mass in the eV range
leaving the other two neutrinos massless. The smallness of this mass scale
(suitable for LSND and Hot Dark Matter) arises without appealing neither to a
see-saw mechanism nor to a radiative mechanism, but from the volume factor
associated with the canonical normalization of the wave-function of the bulk
field in the compactified dimensions. % On the other hand the splitting between
\nm and \nu_sterile (atmospheric scale) as well as the mass of the two other
neutrinos (solar mass scale) arise from the violation of the fermion number on
distant branes. We also discuss alternative scenarios involving
flavour-changing interactions. In one of them \ne can be in the electron-volt
range and therefore be probed in beta decay studies.


title: High Energy Nuclear Collisions

abstract:
  Highlights of the results from ultrarelativistic heavy ion collisions at
CERN-SPS are reviewed. In particular, I discuss how the experimental results
indicate that a collective strongly interacting system has been produced, and
what are the implications towards the Quark Gluon Plasma. The physical ideas
behind measuring certain observables are introduced. The future program of high
energy nuclear collisions at BNL-RHIC and CERN-LHC/ALICE is also briefly
discussed.


title: Comparing Quark Jets in e+e- and DIS

abstract:
  I discuss event cuts in DIS which improve the similarity between the current
Breit hemisphere and hemispheres in $e^+e^-$ annihilation. I also present a
method to study the scale evolution in quark hemispheres using data from fixed
energy $e^+e^-$ experiments. This method can benefit from the high statistics
and flavour tagging at LEP1, also at scales relevant for a comparison with HERA
results.


title: Event Selection Effects on Multiplicities in Quark and Gluon Jets

abstract:
  The properties of quark and gluon jets depend on jet definitions and event
selection. I discuss how these can be included in calculations and present jet
definitions designed to give unbiased jets.


title:
Calculation of Power Corrections to Hadronic Event Shapes of Tagged b
  Events

abstract:
  We compute power corrections to mean values of hadronic event shapes - the
thrust and the C parameter - of tagged b quark events in electron positron
annihilation, using the dispersive approach. We find that the leading power
corrections are of the same type of 1/Q corrections as for event shapes in the
massless case, with the same non-perturbative coefficient times a
perturbatively calculable mass-dependent coefficient. The effect of the mass
correction in the power correction is to reduce the latter by 10-30% for tagged
b events, for centre-of-mass energies ranging from the Z peak down to 20 GeV.


title:
Observables Probing the Perturbative-Nonperturbative Transition Region
  in QCD

abstract:
  Benefiting from the high statistics from $e^+e^-$ experiments at the $Z^0$
resonance, it is possible to impose strong two-jet cuts on the data without
losing the statistical significance. In these events perturbative activity is
suppressed and hadronization effects can be more prominent. I give two examples
of observables that can be important tools for a more detailed study of the
hadronization mechanism.


title:
A model independent analysis of $ B -> X_s \ell^+ \ell^- $ decays in
  supersymmetry

abstract:
  Recently the semileptonic decays $B\to X_s e^+ e^-$, $B\to X_s \mu^+ \mu^-$
in generic supersymmetric extensions of the Standard Model have been studied in
ref.~\cite{noi}. In this talk I review the main points of this analysis. SUSY
effects are parameterized using the mass insertion approximation formalism and
differences with MSSM results are pointed out. Constraints on SUSY
contributions coming from other processes ({\it e.g.} $b\to s \g$) are taken
into account. Chargino and gluino contributions to photon and Z-mediated decays
are computed and non-perturbative corrections are considered. We find that the
integrated branching ratios and the asymmetries can be strongly modified.
Moreover, the behavior of the differential Forward-Backward asymmetry
remarkably changes with respect to the Standard Model expectation.


title: A test of HHCPT using magnetic moments of heavy baryons

abstract:
  First non-trivial chiral corrections to the magnetic moments of triplet (T)
and sextet ($S^{(*)}$) heavy baryons are presented using Heavy Hadron Chiral
Perturbation Theory. The contributions are calculated up to order ${\cal
O}(1/(m_Q \Lambda_\chi^2))$ for T-baryons and up to order ${\cal
O}(1/\Lambda_\chi^2)$ for $S^{(*)}$-baryons. The renormalization of the chiral
loops is discussed and relations among the magnetic moments of different
hadrons are provided.


title: Self-Similar Perturbation Theory

abstract:
  A method is suggested for treating those complicated physical problems for
which exact solutions are not known but a few approximation terms of a
calculational algorithm can be derived. The method permits one to answer the
following rather delicate questions: What can be said about the convergence of
the calculational procedure when only a few its terms are available and how to
decide which of the initial approximations of the perturbative algorithm is
better, when several such initial approximations are possible? Definite answers
to these important questions become possible by employing the self-similar
perturbation theory. The novelty of this paper is in developing the stability
analysis based on the method of multipliers and in illustrating the efficiency
of this analysis by different quantum-mechanical problems.


title:
A double parton scattering background to Higgs boson production at the
  LHC

abstract:
  The experimental capability of recognizing the presence of b quarks in
complex hadronic final states has addressed the attention towards final states
with b\bar{b} pairs for observing the production of the Higgs boson at the LHC,
in the intermediate Higgs mass range.We point out that double parton scattering
processes are going to represent a sizeable background to the process.


title:
New Physics Effects from $e^+e^-\to f\bar f$ at a Linear Collider: the
  Role of $A_{LR, \mu}$

abstract:
  We discuss New Physics effects in fermion pair production at LC in the
framework of the ``Z-peak subtracted approach'', a theoretical scheme that
exploits the experimental measurements at LEP1 and SLC as input parameters. In
particular, we discuss the role of the longitudinal polarization asymmetry
$A_{LR,\mu}$ which turns out to be a very sensitive probe to New Physics of
universal type. The extension of the method to non universal effects is
discussed and an application is given in two examples: general contact
interactions and low energy gravity models with graviton exchange.


title: Extracting GMSB Parameters at a Linear Collider

abstract:
  Assuming gauge-mediated supersymmetry breaking, we simulate precision
measurements of fundamental parameters at a 500 GeV e+e- linear collider in the
scenario where a neutralino is the next-to-lightest supersymmetric particle.
Information on the supersymmetry breaking and the messenger sectors of the
theory is extracted from realistic fits to the measured mass spectrum of the
Minimal Supersymmetric Model particles and the next-to-lightest supersymmetric
particle lifetime.


title: Detection of Charged MSSM Higgs Bosons at CERN LEP-II and NLC

abstract:
  We study the possibility of detecting the charged Higgs bosons predicted in
the Minimal Supersymmetric Standard Model $(H^\pm)$, with the reactions
$e^{+}e^{-}\to \tau^-\bar \nu_{\tau}H^+, \tau^+\nu_\tau H^-$, using the
helicity formalism. We analyze the region of parameter space
$(m_{A^0}-\tan\beta)$ where $H^\pm$ could be detected in the limit when
$\tan\beta$ is large. The numerical computation is done for the energie which
is expected to be available at LEP-II ($\sqrt{s}=200$ GeV) and for a possible
Next Linear $e^{+}e^{-}$ Collider ($\sqrt{s}=500$ GeV).


title: Terrestrial neutrino mass searches

abstract:
  The current status of direct terrestrial neutrino mass searches is presented.
This includes direct kinematical searches, double beta decay and the search for
a magnetic moment.


title: Energy Loss of Ultrahigh Energy Protons in Strong Magnetic Fields

abstract:
  Ultrahigh energy protons in magnetic fields produce pions and thus lose
energy. The mean free path of such a process is worked out for Gaussian random
fields. Two cases are considered: an isotropic and a cylindrically symmetric
distribution. The energy loss is proportional to E^3 <B^2>; it becomes
significant for protons of energies larger than about 10^19 eV and magnetic
fields of about 10^9 Gauss. For energies and magnetic fields of this magnitude,
a proton injected into the magnetic field loses a substantial fraction of its
initial energy due to pion production.


title: Seesaw mechanism and structure of neutrino mass matrix

abstract:
  We consider the seesaw mechanism of neutrino mass generation in the light of
our present knowledge of the neutrino masses and mixing. We analyse the seesaw
mechanism constrained by the following assumptions: (1) minimal seesaw with no
Higgs triplets, (2) hierarchical Dirac masses of neutrinos, (3) large lepton
mixing primarily or solely due to the mixing in the right-handed neutrino
sector, and (4) unrelated Dirac and Majorana sectors of neutrino masses. We
show that large mixing governing the dominant channel of the atmospheric
neutrino oscillations can be naturally obtained and point out that this
constrained seesaw mechanism favours the normal mass hierarchy for the light
neutrinos leading to a small $V_{e3}$ entry of the lepton mixing matrix and a
mass scale of the lightest right handed neutrino $M\simeq 10^{10} - 10^{11}$
GeV. Any of the three main neutrino oscillation solutions to the solar neutrino
problem can be accommodated. The inverted mass hierarchy and quasi-degeneracy
of neutrinos are disfavoured in our scheme.


title: A supersymmetric solution to the KARMEN time anomaly

abstract:
  We interpret the KARMEN time anomaly as being due to the production of a
(dominantly bino) neutralino with mass 33.9 MeV, which is the lightest
supersymmetric particle but decays into 3 leptons through the violation of
R-parity. For independent gaugino masses M_1 and M_2 we find regions in the
(M_1, M_2, mu, tan beta) parameter space where such a light neutralino is
consistent with all experiments. Future tests of this hypothesis are outlined.