title:
$\bar{\rm MS}$ parton densities with NNLO heavy flavor matching
  conditions

abstract:
  A study is made of charm and bottom flavor matching conditions on parton
densities. Starting from an $\bar{\rm MS}$ three-flavor density set, where the
scale $\mu < m_c$, and using the recently derived two-loop matching conditions,
we provide a new set of four-flavor parton densities where $ m_c \le \mu < m_b$
and five-flavor densities where $\mu \ge m_b$. The effect of the
next-to-next-to-leading order matching conditions on the evolution equations is
important for scales just above the transition regions. This includes the small
$x$ and small $Q^2$ domain studied by the H1 and ZEUS experiments at HERA. At
small $x$ the effects of the matching conditions never die away even for large
$\mu^2$.


title:
New Hints for Testing Anomalous Top-Quark Interactions at Future Linear
  Colliders

abstract:
  Angular and energy distributions for leptons and bottom quarks in the process
e^+e^- --> t t-bar --> l^{+-}/b(b-bar) ... have been calculated assuming the
most general top-quark couplings. The double distributions depend both on
modification of the t t-bar production and t(t-bar) --> b(b-bar) W decay
vertices. However, the leptonic angular distribution turned out to be totally
insensitive to non-standard parts of Wtb vertex. Distributions of decay
products for polarized top quark in its rest frame have been also calculated.
It has been found that the factorization of energy and angular dependence for
the double leptonic distribution noticed earlier for the Standard Model
survives even if one allows for deviations from the V-A interactions, and the
SM angular leptonic distribution turned out to be preserved by anomalous decay
vertex.


title: Polarized Heavy Quark Photoproduction in Next to Leading Order

abstract:
  Results of our next-to-leading order analytic calculation for longitudinally
polarized photoproduction of heavy quarks are presented. Certain differential
cross sections and the corresponding asymmetries are computed for energy ranges
accessible to CERN and HERA. We argue that determination of the polarized gluon
distribution is possible at both places: at HERA certain acceptance cuts are
necessary.


title:
On the nonrelativistic dynamics of heavy particles near the production
  threshold

abstract:
  A solution to the Schrodinger equation for the nonrelativistic Green function
which is used for describing the heavy quark-antiquark pair production near the
threshold in $e^+e^-$ annihilation is presented. A quick comparison with
existing results is given. A choice of the effective mass scale for the
nonrelativistic system with Coulomb interaction is discussed.


title: Leading electroweak corrections at the TeV scale

abstract:
  The planned next generation of linear colliders (NLCs) will be able to probe
the infrared structure of Standard Model electroweak interactions, that
determines the behavior of electroweak radiative corrections at TeV scale
energies. I present results of a recent calculation at the leading log level,
and discuss my view on open issues and possible future developments of this new
and interesting subject.


title: Recent Theoretical Progress in ttbar Threshold Analyses

abstract:
  I review the theoretical progress made in these 4 years concerning the
process e+e- -> ttbar in the threshold region. I summarize the progress towards
each of the three major physics goals that should be achieved at ttbar
threshold region.


title:
Phenomenology of a String-Inspired Supersymmetric Model with Inverted
  Scalar Mass Hierarchy

abstract:
  Supersymmetric (SUSY) models with heavy sfermions ($m_{\tilde{f}} \sim 10$
TeV) in the first two generations and the third generation sfermion masses
below 1 TeV can solve the SUSY flavor and the CP problems as well as satisfy
naturalness constraints. We study the phenomenology of a string-inspired
scenario and compare it with the minimal supergravity unified model (mSUGRA).
The SUSY trilepton signature at the upgraded Tevatron, the $b\to s\gamma$
branching fraction and the neutralino dark matter relic density in this model
can differ significantly from the mSUGRA model.


title:
Zee Neutrino Mass Matrix in the Gauge Mediated Supersymmetry Breaking
  Scenario

abstract:
  It is well known that Zee type neutrino mass matrix can provide bi-maximal
neutrino mixing for three neutrinos. We study the reconciliation of this model
with the gauge mediated supersymmetry breaking scenario, which naturally
suppresses the large flavor changing neutral current and CP violation in the
supersymmetric standard model. When the messenger fields have suitable B-L
charges, the radiative correction naturally induces the Zee neutrino mass
matrix, which provides tiny neutrino masses and large lepton flavor mixings.
Our numerical results are consistent with the neutrino oscillation experiments
in both three and four neutrino models.


title: The low-mass sigma-meson: Is it an eyewitness of confinement?

abstract:
  In the framework of the dispersion relation N/D-method we restore the
low-energy pi-pi (IJ^{PC}=00^{++})-wave amplitude sewing it with the previously
obtained K-matrix solution for the region 450--1900 MeV [V.V. Anisovich, Yu.D.
Prokoshkin and A.V. Sarantsev, Phys. Lett. B389, 388 (1996)]. The restored
N/D-amplitude has a pole on the second sheet of the complex-s plane, near the
pi-pi threshold. We discuss the hypothesis that this low-mass pole, or the
low-mass sigma-meson, corresponds to the dynamical state related to the
confinement forces, that is the eyewitness of confinement.


title:
Types of Particle Oscillations and Their Realizations in Neutral K Meson
  and Neutrino Oscillations

abstract:
  Two particle vacuum transitions (oscillations) are studied in the general
case. We found that: 1) a nondiagonal mass term characterising oscillations is
the width of two particle transitions into each other (this width can be
computed by the standard method); 2) two types of oscillations take place: real
and virtual. Solution of the problem of origin of mixing angle in the theory of
vacuum oscillations is given. It is shown that neutral K meson and neutrino
oscillations must proceed via two stages. First, neutral K^{o}, antineutral
K-eigenstates of strong interaction (or nu(e), nu(mu), nu(tau) eigenstates of
weak interactions) are created. Then, owing to the presence of the strangeness
violating weak interaction (or the lepton number violating interactions), these
meson states (or neutrino states) are converted into superpositions of neutral
K(1) and neutral K(2)-eigenstates of the weak interaction violating strangeness
(or nu(1), nu(2), nu(3)-eigenstates of the interaction-violating lepton
numbers). Further, neutral K-meson or neutrino oscillations will occur in
accordance with the standard scheme.


title: Chiral restoration in effective quark models with non-local interactions

abstract:
  Chiral restoration at finite temperatures is studied in chiral quark models
with non-local regulators. At the leading-N_c level we find transition
temperatures of the order of 100MeV. Meson-loop contributions are also analyzed
and found to have a very small effect.


title:
Variational calculations with improved energy functionals in gauge
  theories

abstract:
  For a SU(N) Yang-Mills theory, we present variational calculations using
gaussian wave functionals combined with an approximate projection on gauge
invariant states. The projection amounts to correcting the energy of the
gaussian states by substracting the spurious energy associated with gauge
rotations. Based on this improved energy functional, we perform variational
calculations of the interaction energy in the presence of external electric and
magnetic fields. We verify that the ultraviolet behaviour of our approximation
scheme is consistent, as it should, with that expected from perturbation
theory. In particular, we recover in this variational framework the standard
one-loop beta function, with a transparent interpretation of the screening and
anti-screening contributions.


title:
QCDINS 2.0 - A Monte Carlo generator for instanton-induced processes in
  deep-inelastic scattering

abstract:
  We describe a Monte Carlo event generator for the simulation of QCD-instanton
induced processes in deep-inelastic scattering (HERA). The QCDINS package is
designed as an ``add-on'' hard process generator interfaced to the general
hadronic event simulation package HERWIG. It incorporates the theoretically
predicted production rate for instanton-induced events as well as the essential
characteristics that have been derived theoretically for the partonic final
state of instanton-induced processes: notably, the flavour democratic and
isotropic production of the partonic final state, energy weight factors
different for gluons and quarks, and a high average multiplicity O(10) of
produced partons with a Poisson distribution of the gluon multiplicity. While
the subsequent perturbative evolution of the generated partons is always
handled by the HERWIG package, the final hadronization step may optionally be
performed also by means of the general hadronic event simulation package
JETSET.


title: A Note on New Sources of Gaugino Masses

abstract:
  In IIB orientifold models, the singlet twisted moduli appear in the
tree-level gauge kinetic function. They might be responsible for generating
gaugino masses if they acquire non-vanishing F-terms. We discuss some aspects
of this new possibility, such as the size of gaugino masses and their
non-universalities. A possible brane setting is presented to illustrate the
usefulness of these new sources.


title: Quark-binding effects in inclusive decays of heavy mesons

abstract:
  We present a new approach to the analysis of quark-binding effects in
inclusive decays of heavy mesons within the relativistic dispersion quark
model. Various differential distributions, such as electron energy spectrum,
$q^2$- and $M_X$-distributions, are calculated in terms of the $B$ meson soft
wave function which also determines long-distance effects in exclusive
transition form factors. Using the quark-model parameters and the $B$ meson
wave function previously determined from the description of the exclusive $b
\to u$ transitions within the same dispersion approach, we provide numerical
results on various distributions in the inclusive $B \to X_c l\nu$ decays.


title: Soft High Energy Scattering in Nonperturbative QCD

abstract:
  In this report diffractive high energy reactions are discussed in a
functional integral approach where hadronic amplitudes are calculated from
vacuum expectation values of lightlike Wegner-Wilson loops. In the first part
we calculate elastic differential cross sections for high energy and small
momentum transfer elastic proton-proton (pp) scattering which are in reasonable
agreement with the experimental data. In the second part we consider exclusive
$\pi^0$ production in ep-scattering. At high energies photon and odderon
exchange contribute to this reaction. We show that odderon exchange leads to a
much larger inelastic than elastic $\pi^0$ production cross section, dominating
the $\gamma$ contribution by orders of magnitude. Observing our process at HERA
would establish the soft odderon.


title:
Pionium lifetime and \pi\pi scattering lengths in generalized chiral
  perurbation theory

abstract:
  The relationship between the pionium lifetime and the $\pi\pi$ scattering
lengths is established, including the sizable electromagnetic corrections. The
bound state formalism that is used is that of constraint theory which provides
a covariant three-dimensional reduction of the Bethe--Salpeter equation. The
framework of generalized chiral perturbation theory allows then an analysis of
the lifetime value as a function of the $\pi\pi$ scattering lengths, the latter
being dependent on the quark condensate value.


title: Dynamics of Symmetry Breaking in FRW Cosmologies: Emergence of Scaling

abstract:
  The dynamics of a symmetry breaking phase transition is studied in a
radiation and matter dominated spatially flat FRW cosmology in the large N
limit of a scalar field theory.The quantum density matrix is evolved from an
initial state of quasiparticles in thermal equilibrium at a temperature higher
than the critical. The cosmological expansion decreases the temperature and
triggers the phase transition. We identify three different time scales: an
early regime dominated by linear instabilities and the exponential growth of
long-wavelength fluctuations,an intermediate scale when the field fluctuations
probe the broken symmetry states and an asymptotic scale wherein a scaling
regime emerges for modes of wavelength comparable to or larger than the
horizon.The scaling regime is characterized by a dynamical physical correlation
length xi_{phys} = d_H(t) with d_H(t) the size of the causal horizon, thus
there is one correlated region per causal horizon. Inside these correlated
regions the field fluctuations sample the broken symmetry states. The amplitude
of the long-wavelength fluctuations becomes non-perturbatively large due to the
early times instabilities and a semiclassical but stochastic description
emerges in the asymptotic regime. In the scaling regime, the power spectrum is
peaked at zero momentum revealing the onset of a Bose-Einstein condensate.The
scaling solution results in that the equation of state of the scalar fields is
the same as that of the background fluid. This implies a Harrison-Zeldovich
spectrum of scalar density perturbations for long-wavelengths. We discuss the
corrections to scaling as well as the universality of the scaling solution and
the differences and similarities with the classical non-linear sigma model.


title:
Direct CP violation in K->3pi decays induced by SUSY chromomagnetic
  penguins

abstract:
  An analysis of the CP violating asymmetry in $K^\pm \to (3\pi)^\pm$ decays in
the Standard Model and, by means of the mass insertion approximation, in a wide
class of possible supersymmetric extensions, is presented. We find that the
natural order of magnitude for this asymmetry is $\cO(10^{-5})$ in both cases.
Within supersymmetric models effects as large as $\cO(10^{-4})$ are possible,
but only in a restricted range of the relevant parameters.


title:
Diffractive Dissociation Including Multiple Pomeron Exchanges in High
  Parton Density QCD

abstract:
  We derive an evolution equation describing the high energy behavior of the
cross section for the single diffractive dissociation in deep inelastic
scattering on a hadron or a nucleus. The evolution equation resums multiple
BFKL pomeron exchanges contributing to the cross section of the events with
large rapidity gaps. Analyzing the properties of an approximate solution of the
proposed equation we point out that at very high energies there is a
possibility that for a fixed center of mass energy the cross section will reach
a local maximum at a certain intermediate size of the rapidity gap, or,
equivalently, at some non-zero value of the invariant mass of the produced
particles.


title:
Long-Baseline Study of the Leading Neutrino Oscillation at a Neutrino
  Factory

abstract:
  Within the framework of three-flavor neutrino oscillations, we consider the
physics potential of \nu_e --> \nu_\mu appearance and \nu_\mu --> \nu_\mu
survival measurements at a neutrino factory for a leading oscillation scale
\delta m^2 ~ 3.5 \times 10^{-3} eV^2. Event rates are evaluated versus baseline
and stored muon energy, and optimal values discussed. Over a sizeable region of
oscillation parameter space, matter effects would enable the sign of \delta m^2
to be determined from a comparison of \nu_e --> \nu_\mu with \bar\nu_e -->
\bar\nu_\mu event rates and energy distributions. It is important, therefore,
that both positive and negative muons can be stored in the ring. Measurements
of the \nu_\mu --> \nu_\mu survival spectrum could determine the magnitude of
\delta m^2 and the leading oscillation amplitude with a precision of O(1%--2%).


title: Supersymmetry and Duality in Field Theory and String Theory

abstract:
  This is a set of lectures given at the 99' Cargese Summer School: Particle
Physics : Ideas and Recent Developments. They contain a pedestrian exposition
of recent theoretical progress in non-perturbative field theory and string
theory based on ideas of duality.


title: CP violation in the semileptonic top decay in two-Higgs doublet model

abstract:
  CP violation in semileptonic top-quark decay is investigated by exactly using
one charged- and three neutral-Higgs bosons obtained by solving the Higgs mass
matrix in two-Higgs doublet model. The CP-violating up-down asymmetry of
leptons from $W$ boson decays is shown to be $1 \times 10^{-4} - 4 \times
10^{-3}$ for the region of ${\rm tan} \beta \ll 1$, where ${\rm tan} \beta $ is
the ratio of vacuum expectation values for the two neutral Higgs bosons.


title:
1/m_Q Corrections to the Bethe-Salpeter Equation for \Lambda_{Q} in the
  Diquark Picture

abstract:
  Corrections of order 1/m_Q (Q=b or c) to the Bethe-Salpeter (B-S) equation
for \Lambda_Q are analyzed on the assumption that the heavy baryon \Lambda_Q is
composed of a heavy quark and a scalar, light diquark. It is found that in
addition to the one B-S scalar function in the limit m_Q -> \infty, two more
scalar functions are needed at the order 1/m_Q. These can be related to the B-S
scalar function in the leading order. The six form factors for the weak
transition \Lambda_b -> \Lambda_c are expressed in terms of these wave
functions and the results are consistent with heavy quark effective theory to
order 1/m_Q. Assuming the kernel for the B-S equation in the limit m_Q ->
\infty to consist of a scalar confinement term and a one-gluon-exchange term we
obtain numerical solutions for the B-S wave functions, and hence for the
$\Lambda_b \to \Lambda_c$ form factors to order 1/m_Q. Predictions are given
for the differential and total decay widths for \Lambda_b -> \Lambda_c l
\bar{\nu}, and also for the nonleptonic decay widths for \Lambda_b -> \Lambda_c
plus a pseudoscalar or vector meson, with QCD corrections being also included.


title:
Possibility of Large Final State Interaction Phases in Light of B \to
  K\pi and \pi\pi Data

abstract:
  The newly observed $\bar B^0 \to \bar K^0\pi^0$ mode is quite sizable while
$\pi^-\pi^+$ is rather small. Data also hint at $\pi^-\pi^0 \gtrsim
\pi^-\pi^+$. Though consistent with zero, central values of CP violating
asymmetries in $K^-\pi^{+,0}$ and $\bar K^0\pi^-$ show an interesting pattern.
Taking cue from these, we suggest that, besides $\gamma\equiv {\rm arg}
(V_{ub}^*)$ being large, the rescattering phase $\delta$ in $K\pi$ and $\pi\pi$
modes may be greater than $90^\circ$. If this is true, not only the above
trends can be accounted for, one would also find $\pi^0\pi^0 \sim
\pi^-\pi^{+,0}$, and the CP asymmetry in $\bar B^0$ vs. $B^0 \to \pi^-\pi^+$
could be as large as -60%. These results can be tested in a couple of years.


title: QCD corrections to e+ e- --> 4 jets

abstract:
  We report on the next-to-leading order QCD calculation for e+ e- --> 4 jets.
We explain some modern techniques which have been used to calculate the
one-loop amplitudes efficiently. We further report on the general purpose
numerical program ``Mercutio'', which can be used to calculate any infrared
safe four-jet quantity in electron-positron annihilation at next-to-leading
order.


title: QCD sum rules on the light cone and B -> pi form factors

abstract:
  The semileptonic decay B -> pi l nu is one of the most important reactions
for the determination of the CKM matrix element |V_{ub}|. However, in order to
extract |V_{ub}| from data one needs an accurate theoretical calculation of the
hadronic matrix element describing the B to pi transition. QCD sum rules, based
on operator-product expansion on the light-cone, provide a reliable approach to
this aim. QCD corrections and higher twist contributions can be taken
systematically into account.


title:
Chiral dynamics of many pion systems: the rho to 4 pi and omega to 5 pi
  decays

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: QCD Inequalities

abstract:
  We review the subject of QCD inequalities, using both a Hamiltonian
variational approach, and a rigorous Euclidean path integral approach.


title: On Global Structure of Hadronic Total Cross-Sections

abstract:
  Simple theoretical formula describing the global structure of pp and p\bar p
total cross-secrions in the whole range of energies available up today has been
derived. The fit to the experimental data with the formula has been made. It is
shown that there is a very good correspondence of the theoretical formula to
the existing experimental data.


title: Test of factorisation in $B \to K\pi$ decays

abstract:
  We analyse the $B \to K\pi$ decays using the factorisation model with final
state interaction phase shift included. We find that factorisation seems to
describe qualitatively the latest CLEO data. For a test of the factorisation
model, we derive a relation for the branching ratios independent of the
strength of the strong penguin interactions. This relation gives a central
value of $(0.60 \times 10^{-5})$ for ${\mathcal B}(\bar{B}^{0} \to
\bar{K}^{0}\pi^{0})$, somewhat smaller than the latest CLEO measurement, but
the experimental errors are yet too big to take it as a real prediction of the
factorisation model. We also find that a ratio obtained from the CP-averaged $B
\to K\pi$ decay rates could be used to test the factorisation model and to
determine the weak angle $\gamma$ with more precise data, though the l atest
CLEO data seem to favor $\gamma$ in the range of $(90^{\circ}-120^{\circ})$.


title: Extra quark-lepton generations and precision measurements

abstract:
  The existence of extra chiral generations with all fermions heavier than M_Z
is strongly disfavoured by the precision electroweak data. However the data are
fitted nicely even by a few extra generations, if one allows neutral leptons to
have masses close to 50 GeV. The data allow inclusion of one additional
generation of heavy fermions in SUSY extension of Standard Model if chargino
and neutralino have masses close to 60 GeV with \Delta m =~ 1 GeV.


title: Vector Boson Transverse Momentum Distributions at the Tevatron

abstract:
  We show vector boson transverse momentum distributions at the Tevatron,
obtained by running the HERWIG Monte Carlo event generator with matrix-element
corrections. We compare our results with some recent D0 and CDF data.


title:
Non-equilibrium dynamics in quantum field theory at high density: the
  tsunami

abstract:
  The dynamics of a dense relativistic quantum fluid out of thermodynamic
equilibrium is studied in the framework of the Phi^4 scalar field theory in the
large N limit. The time evolution of a particle distribution in momentum space
(the tsunami) is computed. The effective mass felt by the particles in such a
high density medium equals the tree level mass plus the expectation value of
the squared field. The case of negative tree level squared mass is particularly
interesting. In such case dynamical symmetry restoration as well as dynamical
symmetry breaking can happen. Furthermore, the symmetry may stay broken with
vanishing asymptotic squared mass showing the presence of out of equilibrium
Goldstone bosons. We study these phenomena and identify the set of initial
conditions that lead to each case. We compute the equation of state which turns
to depend on the initial state. Although the system does not thermalize, the
equation of state for asymptotically broken symmetry is of radiation type. We
compute the correlation functions at equal times. The two point correlator for
late times is the sum of different terms. One stems from the initial particle
distribution. Another term accounts for the out of equilibrium Goldstone bosons
created by spinodal unstabilities when the symmetry is asymptotically
broken.Both terms are of the order of the inverse of the coupling for distances
where causal signals can connect the two points. The contribution of the out of
equilibrium Goldstones exhibits scaling behaviour in a generalized sense.


title: A Model of Interacting Partons for Hadronic Structure Functions

abstract:
  We present a model for the structure of baryons in which the valence partons
interact through a linear potential. This model can be derived from QCD in the
approximation where transverse momenta are ignored. We compare the valence
quark distribution function predicted by our model with that extracted from
global fits to Deep Inelastic Scattering data. The only parameter we can adjust
is the fraction of baryon momentum carried by valence partons. Our predictions
agree well with data except for small values of the Bjorken scaling variable.


title:
Model independent constraints on leptoquarks from MU and TAU lepton rare
  processes

abstract:
  We perform a model independent analysis so as to constrain the leptoquark
(LQ) models from negative searches for $\mu \to e \gamma$, $\mu \to 3e$ decays
(and analogous processes in the $\tau$ sector), and coherent $\mu-e$ conversion
in nuclei. We considerably improve some constraints obtained by analyses known
in the literature, analyses which we show have by far underestimated the LQ
contributions to the $\mu\to 3e$. In particular we find that the coherent
$\mu-e$ conversion in nuclei mediated by the photon--conversion mechanism and
the $\mu \to 3e$ decay are golden plates where the flavor changing leptoquark
couplings, involving the second and third quark generations, can be strongly
constrained. This is due to the fact that these processes get the enhancements
by large $\log(m_q^2/m^2_{LQ})$ terms which are induced by the so-called
``photon-penguin'' diagrams. These enhancements, which produce a mild GIM
suppression in the amplitudes, have not been taken into account in the previous
analyses. We show that the $\mu \to e \gamma$ decay can set weaker constraints
on the LQ models and this is because its amplitude is strongly GIM suppressed
by the terms of order $O(m_q^2/m^2_{LQ})$. We also present the results for the
corresponding constraints in the $\tau$ sector. Finally the prospects of the
future muon experiments for the improvement of the present bounds are analyzed
and discussed.


title: GUTs and String-GUTs

abstract:
  We look for a connection between string theories and Grand Unified Theories
(GUTs), with the aim to look for new insights in the existing four dimensional
string-GUT problems. We argue that the construction of consistent string-GUT
models could require the use of non canonical affine levels. We list the most
common level values related to realistic GUTs.


title:
Possible enhancement of the $e^+ e^- \to H^\pm W^\mp$ cross section in
  the two-Higgs-doublet model

abstract:
  The production process of the charged Higgs-boson associated with a $W$ boson
at electron-positron colliders is discussed in the two-Higgs-Doublet Model
(2HDM) and in the Minimal Supersymmetric Standard Model (MSSM). The process is
induced at one-loop level in these models. We examine how much the cross
section can be enhanced by quark- and Higgs-loop effects. In the non-SUSY 2HDM,
in addition to large top-bottom ($t$-$b$) loop effects for small $\tan \beta$
($\ll \sqrt{m_t/m_b}$), the Higgs-loop diagrams can contribute to the cross
section to some extent for moderate $\tan \beta$ values. For larger $\tan
\beta$ ($\gg \sqrt{m_t/m_b}$), such enhancement by the Higgs non-decoupling
effects is bounded by the requirement for validity of perturbation theory. In
the MSSM with heavy super-partner particles, only the $t$-$b$ loops enhance the
cross section while Higgs-loop effects are very small.


title:
Baryon Octet magnetic moments in $\chi$PT: More on the importance of the
  Decuplet

abstract:
  We address the impact of treating the decuplet of spin-3/2 baryons as an
explicit degree of freedom in the chiral expansion of the magnetic moments of
the octet of spin-1/2 baryons. We carry out a complete calculation of the octet
moments to O(1/\lamchic), including decuplet contributions to the chiral loops.
In contrast to results of previous analyses, we find that inclusion of the
decuplet preserves the convergence behavior of the chiral expansion implied by
power counting arguments.


title:
Further Analysis of Di-gluon Fusion Mechanism for the decays of $B \to K
  \eta^{\prime}$

abstract:
  Di-gluon fusion mechanism might account for the large branching ratios of
$B\to K \eta^{\prime}$. But because we know little about the effective
$\eta^{\prime}gg$ vertex, there are large uncertainties in perturbative QCD
estimations. In this paper, we try several kinds of $\eta^{\prime}gg$ form
factors and compare the numerical results with the experiment. We find that,
though we know little about $\eta^{\prime}gg$ form factor, if di-gluon fusion
mechanism is important in $B\to K \eta^{\prime}$, the branching ratios of the
decays $B\to K^{\ast} \eta^{\prime}$ would be around $10^{-5}$ which can be
tested by future experiments.


title:
On the Relation between the Slopes of Diffraction Cone in Single
  Diffraction Dissociation and Elastic Scattering

abstract:
  The fundamental relation between the slopes of diffraction cone in single
diffraction dissociation and elastic scattering has been derived.


title:
Classification of higher order diagrams in non-equilibrium theory, and
  the removal of pinch singularities

abstract:
  The non-equilibrium two loop self-energy is reexamined in the framework of a
scalar quark and gluon model, with specific attention to terms which do not
give rise to the standard two -> two particle collisional terms in the
semi-classical Boltzmann equation. It is shown that most of these terms
contribute to renormalization of component lines at a lower level, rendering
the theory correct to (gm)^4. This result can be generalized to a higher number
of loops. The remaining terms, which do not fall into any physical category,
are shown explicitly to vanish. We then examine the possibility that pinch
singularities could arise in this theory, and demonstrate that this is not so
for the case of equilibrium and small deviations from equilibrium, at the two
loop level.


title: Neutrino masses from nonstandard supersymmetry breaking terms

abstract:
  Naturally small Majorana neutrino masses arise from nonstandard supersymmetry
breaking terms. This mechanism works in the minimal supersymmetric framework
and does not require extra particles or new mass scales. It could also be
responsible for proton decay even in the absence of Grand Unification.


title: Linking solar and long baseline terrestrial neutrino experiments

abstract:
  We show that in the framework of three light neutrino species with
hierarchical masses and assuming no fine tuning between the entries of the
neutrino mass matrix, one can use the solar neutrino data to obtain information
on the element $U_{e3}$ of the lepton mixing matrix. Conversely, a measurement
of $U_{e3}$ in atmospheric or long baseline accelerator or reactor neutrino
experiments would help discriminate between possible oscillation solutions of
the solar neutrino problem.


title: Results in next-to-leading-log prompt-photon hadroproduction

abstract:
  We present some results on renormalization and factorization scale dependence
of soft-gluon resummation, at the next-to-leading-logarithmic level, in the
fixed-target hadro-production cross-section for prompt photons.


title: Seeds of Large Scale Anisotropy in Pre-Big-Bang Cosmology

abstract:
  Within a string cosmology context, the large scale temperature anisotropies
may arise from the contribution of seeds to the metric fluctuations. We study
the cases of electromagnetic and axion seeds. We find that massless or very
light axions can lead to a flat or slightly tilted blue spectrum, that fits
current data.


title:
Langevin equations with multiplicative noise: resolution of time
  discretization ambiguities for equilibrium systems

abstract:
  A Langevin equation with multiplicative noise is an equation schematically of
the form dq/dt = -F(q) + e(q) xi, where e(q) xi is Gaussian white noise whose
amplitude e(q) depends on q itself. Such equations are ambiguous, and depend on
the details of one's convention for discretizing time when solving them. I show
that these ambiguities are uniquely resolved if the system has a known
equilibrium distribution exp[-V(q)/T] and if, at some more fundamental level,
the physics of the system is reversible. I also discuss a simple example where
this happens, which is the small frequency limit of Newton's equation d^2q/dt^2
+ e^2(q) dq/dt = - grad V(q) + e^{-1}(q) xi with noise and a q-dependent
damping term. The resolution does not correspond to simply interpreting naive
continuum equations in a standard convention, such as Stratanovich or Ito. [One
application of Langevin equations with multiplicative noise is to certain
effective theories for hot, non-Abelian plasmas.]


title:
Symmetric path integrals for stochastic equations with multiplicative
  noise

abstract:
  A Langevin equation with multiplicative noise is an equation schematically of
the form dq/dt = - F(q) + e(q) xi, where e(q) xi is Gaussian white noise whose
amplitude e(q) depends on q itself. I show how to convert such equations into
path integrals. The definition of the path integral depends crucially on the
convention used for discretizing time, and I specifically derive the correct
path integral when the convention used is the natural, time-symmetric one that
time derivatives are (q_t - q_{t-\Delta t}) / \Delta t and coordinates are (q_t
+ q_{t-\Delta t}) / 2. [This is the convention that permits standard
manipulations of calculus on the action, like naive integration by parts.] It
has sometimes been assumed in the literature that a Stratanovich Langevin
equation can be quickly converted to a path integral by treating time as
continuous but using the rule \theta(t=0) = 1/2. I show that this prescription
fails when the amplitude e(q) is q-dependent.


title: Slepton Flavour Mixing and Neutrino Masses

abstract:
  It is pointed out that important contribution to neutrino masses and mixing
can come from flavour violating slepton exchange. For low and intermediate
$\tan\beta$ such effects can dominate over the usual tau Yukawa coupling
effects included in the renormalization group evolution. The mixing angles
satisfy then the relation different from the fixed point solution of the
renormalization group equation, and the desired neutrino mass splitting can be
generated.


title: Four-Neutrino Mixing and Long-Baseline Experiments

abstract:
  We consider the two four-neutrino schemes that are compatible with all
neutrino oscillation data. We present the range of the corresponding mixing
parameters allowed by the results of neutrino oscillation experiments. We
discuss the implications for long-baseline experiments and we suggest the
possibility to reveal the presence of CP-violating phases through a comparison
of the oscillation probability measured in long-baseline experiments with the
corresponding average oscillation probability measured in short-baseline
experiments.


title: The equivalence theorem and the production of gravitinos after inflation

abstract:
  We study the high-energy equivalence between helicity 1/2 gravitinos and
goldstinos in order to calculate the production of gravitinos in time-dependent
scalar and gravitational backgrounds. We derive this equivalence for equations
of motion, paying attention to some subtleties, mainly due to external sources,
that are not present in the standard proofs. We also propose the Landau gauge
as a simplifying alternative to the usual gauge choices, both for practical
calculations and in the equivalence theorem proof.


title:
Coherence Time Effects on J/psi Production and Suppression in
  Relativistic Heavy Ion Collisions

abstract:
  Using a coherence time extracted from high precision proton-nucleus Drell-Yan
measurements and a nuclear absorption cross section extracted from pA
charmonium production experiments, we study J/psi production and absorption in
nucleus-nucleus collisions. We find that coherence time effects are large
enough to affect the measured J/psi-to-Drell-Yan ratio. The S+U data at 200A
GeV/c measured by NA38 are reproduced quantitatively without the introduction
of any new parameters. However, when compared with recent NA50 measurements for
Pb+Pb at 158A GeV/c, the data is not reproduced in trend or in magnitude.


title:
The Precision Monte Carlo Event Generator KK For Two-Fermion Final
  States In e+e- Collisions

abstract:
  We present the Monte Carlo event generator KK version 4.13 for precision
predictions of the Electroweak Standard Model for the process $e^+e^-\to
f\bar{f} +n\gamma$, $f=\mu,\tau,d,u,s,c,b$ at centre of mass energies from
$\tau$ lepton threshold to 1TeV, that is for LEP, SLC, future Linear Colliders,
$b,c,\tau$-factories etc. Effects due to photon emission from initial beams and
outgoing fermions are calculated in QED up to second order, including all
interference effects, within Coherent Exclusive Exponentiation (CEEX), which is
based on Yennie-Frautschi-Suura exponentiation. Electroweak corrections are
included in first order, with higher order extensions, using the DIZET 6.x
library. Final state quarks hadronize according to the parton shower model
using JETSET. Beams can be polarized longitudinally and transversely. Decay of
the tau leptons is simulated using the TAUOLA library, taking into account spin
polarization effects as well. In particular the complete spin correlations
density matrix of the initial state beams and final state tau's is incorporated
in an exact manner. Effects due to beamstrahlung are simulated in a realistic
way. The main improvements with respect to KORALZ are: (a) inclusion of the
initial-final state QED interference, (b) inclusion of the exact matrix element
for two photons, and (c) inclusion of the transverse spin correlations in
$\tau$ decays (as in KORALB).


title:
On the sign of the neutrino asymmetry induced by active-sterile neutrino
  oscillations in the early Universe

abstract:
  We deal with the problem of the final sign of the neutrino asymmetry
generated by active-sterile neutrino oscillations in the Early Universe solving
the full momentum dependent quantum kinetic equations. We study the parameter
region $10^{-2} \stackrel{<}{\sim} |\delta m^2|/eV^2\le 10^3$. For a large
range of $\sin^2 2\theta_0$ values the sign of the neutrino asymmetry is fixed
and does not oscillate. For values of mixing parameters in the region
$10^{-6}\stackrel{<}{\sim}\sin^{2}2\theta_{0}\stackrel{<}{\sim} 3\times 10^{-4}
({\rm eV}^{2}/|\delta m^{2}|)$, the neutrino asymmetry appears to undergo rapid
oscillations during the period where the exponential growth occurs. Our
numerical results indicate that the oscillations are able to change the
neutrino asymmetry sign. The sensitivity of the solutions and in particular of
the final sign of lepton number to small changes in the initial conditions
depends whether the number of oscillations is high enough. It is however not
possible to conclude whether this effect is induced by the presence of a
numerical error or is an intrinsic feature. As the amplitude of the statistical
fluctuations is much lower than the numerical error, our numerical analysis
cannot demonstrate the possibility of a chaotical generation of lepton domains.
In any case this possibility is confined to a special region in the space of
mixing parameters and it cannot spoil the compatibility of the
$\nu_{\mu}\leftrightarrow\nu_{s}$ solution to the neutrino atmospheric data
obtained assuming a small mixing of the $\nu_{s}$ with an ${\rm eV}-\tau$
neutrino.


title: Scale Anomaly and "Soft" Pomeron in QCD

abstract:
  We propose a new non-perturbative approach to hadronic interactions at high
energies and small momentum transfer, which is based on the scale anomaly of
QCD and emphasizes the role of semi-classical vacuum fields. We find that the
hadron scattering amplitudes exhibit Regge behavior and evaluate the intercept
alpha(0) of the corresponding trajectory. Both the intercept and the scale for
the slope of the trajectory appear to be determined by the energy density of
non-perturbative QCD vacuum (the gluon condensate). Numerically, we find Delta
= alpha(0) - 1 = 0.08 -0.1, consistent with the values ascribed
phenomenologically to the ``soft'' Pomeron. For arbitrary numbers of colors N_c
and flavors N_f, Delta is found to be proportional to (N_f/N_c)^2; however, in
the large N_c (N_f fixed) limit, Delta \sim N_c^0.


title:
Resonant single chargino and neutralino versus fermion-antifermion
  production at the Linear Collider

abstract:
  We study single superparticle productions at the linear collider, putting
particular emphasis on resonant processes. We find that there exists a wide
region of model parameters where single chargino and neutralino productions
dominate over R-violating fermion-antifermion final states. For certain values
of mu and M_2 it is possible to produce even the heavier charginos and
neutralinos at significant rates, amplifying the total cross section and
obtaining interesting chains of cascade decays. Effects from initial-state
radiation are also included.


title: Quintessence, Flat Potential and String/M Theory Axion

abstract:
  A slow-rolling scalar field (Quintessence) has been proposed as the origin of
accelerating universe at present. We discuss some features of quintessence,
particularly those related with the {\it flatness} of its potential. We
distinguish two types of quintessences, a metrical quintessence which couples
to the particle physics sector {\it only} through the mixing with the spacetime
metric and a non-metrical one without such property. It is stressed that these
two types of quintessences have quite different features in regard to the fine
tuning of parameters required for the flat potential, as well as different
implications for the quintessence-mediated long range force. The fine tuning
argument strongly suggests that non-metrical quintessence should correspond to
the Goldstone boson of an almost exact nonlinear global symmetry whose explicit
breaking by quantum gravity effects is highly suppressed. It is briefly
discussed whether the radion field in higher dimensional theories can be a
candidate for metrical quintessence. We finally discuss the possibility that
string/$M$ theory axion corresponds to a Goldstone-type quintessence, and argue
that a certain combination of the heterotic $M$ theory or Type I string theory
axions can be a good candidate for quintessence if some conditions on the
moduli dynamics are satisfied.


title: Flow equations in light-front QCD

abstract:
  Light-front QCD is studied by the method of flow equations. Dynamical gluon
mass is generated, which evolves with the cut-off according to renormalization
group equation. Eliminating by flow equations the quark gluon coupling with the
dynamical gluon mode, one obtains an effective interaction between quark and
antiquark which exibits the Coulomb and confining singularities. The scale,
which regulates the light-front IR singularities in the gluon sector, defines
the string tension of confining interaction. The mechanism of confinement in
the light-front formalism is suggested, based on the singular nature of the
light-front gauge.


title: Model independent shape analysis of correlations in 1, 2 or 3 dimensions

abstract:
  A generic, model-independent method for the analysis of the two-particle
short-range correlations is presented, that can be utilized to describe e.g.
Bose-Einstein (HBT or GGLP), statistical, dynamical or other short-range
correlation functions. The method is based on a data-motivated choice for the
zero-th order approximation for the shape of the correlation function, and on a
systematic determination of the correction terms with the help of complete
orthonormal set of functions. The Edgeworth expansion is obtained for
approximately Gaussian, the Laguerre expansion for approximately exponential
correlation functions. Multi-dimensional expansions are also introduced and
discussed.


title:
Computation of quark mass anomalous dimension at O(1/N_f^2) in quantum
  chromodynamics

abstract:
  We present the formalism to calculate d-dimensional critical exponents in QCD
in the large N_f expansion where N_f is the number of quark flavours. It relies
in part on demonstrating that at the d-dimensional fixed point of QCD the
critical theory is equivalent to a non-abelian version of the Thirring model.
We describe the techniques used to compute critical two and three loop Feynman
diagrams and as an application determine the quark wave function, eta, and mass
renormalization critical exponents at O(1/N_f^2) in d-dimensions. Their values
when expressed in relation to four dimensional perturbation theory are in exact
agreement with the known four loop MSbar results. Moreover, new coefficients in
these renormalization group functions are determined to six loops and
O(1/N_f^2). The computation of the exponents in the Schwinger Dyson approach is
also provided and an expression for eta in arbitrary covariant gauge is given.


title:
Masses of Decuplet Baryons Treated within Anyonic Realization of the
  q-Algebras U_q(su_N)

abstract:
  In the approach to hadronic flavour symmetries based on the q-algebras
U_q(su_N) and proved to be realistic, the known construction of U_q(su_N) in
terms of anyonic oscillators residing on 2d lattice is utilized. Anyonic
Fock-like realization of basis state vectors is given for baryons (3/2)^+ from
the 10-plet of U_q(su_3) embedded, via 20-plet of U_q(su_4), into the
"dynamical" representation [4000] of U_q(su_5). Within the anyonic picture, we
reobtain the universal q-deformed decuplet mass relation
M_\Omega-M_{\Xi^*}+M_{\Sigma^*}-M_{\Delta}=[2]_q (M_{\Xi^*}-M_{\Sigma^*}),
where [2]_q=q+q^{-1}=2 cos{\theta}. Consistency with data for baryon masses
requires \theta\simeq\frac{\pi}{14}. As a result, anyons with anyonic
statistics parameter \nu = 1/14 can be put into correspondence, at least
formally, with the constituent quarks of decuplet baryons.


title:
Suggestions for Improved Benchmark Scenarios for Higgs-Boson Searches at
  LEP2

abstract:
  We suggest new benchmark scenarios for the Higgs-boson search at LEP2.
Keeping m_t and M_SUSY fixed, we improve on the definition of the maximal
mixing benchmark scenario defining precisely the values of all MSSM parameters
such that the new m_h^max benchmark scenario yields the parameters which
maximize the value of m_h for a given tan(beta). The corresponding scenario
with vanishing mixing in the scalar top sector is also considered. We propose a
further benchmark scenario with a relatively large value of |mu|, a moderate
value of M_SUSY, and moderate mixing parameters in the scalar top sector. While
the latter scenario yields m_h values that in principle allow to access the
complete M_A-tan(beta)-plane at LEP2, on the other hand it contains parameter
regions where the Higgs-boson detection can be difficult, because of a
suppression of the branching ratio of its decay into bottom quarks.


title:
LHC sensitivity to the resonance spectrum of a minimal strongly
  interacting electroweak symmetry breaking sector

abstract:
  We present a unified analysis of the two main production processes of vector
boson pairs at the LHC, VV-fusion and qqbar annihilation, in a minimal strongly
interacting electroweak symmetry breaking sector. Using a unitarized
electroweak chiral Lagrangian formalism and modeling the final V_L V_L strong
rescattering effects by a form factor, we describe qqbar annihilation processes
in terms of the two chiral parameters that govern elastic V_L V_L scattering.
Depending on the values of these two chiral parameters, the unitarized
amplitudes may present resonant enhancements in different angular
momentum-isospin channels. Scanning this two parameter space, we generate the
general resonance spectrum of a minimal strongly interacting electroweak
symmetry breaking sector and determine the regions that can be probed at the
LHC.


title: Influence of solar chaotic magnetic fields on neutrino oscillations

abstract:
  We consider the effect of a random magnetic field in the convective zone of
the Sun on resonant neutrino spin-flavour oscillations. The expected signals in
the different experiments (SK, GALLEX-SAGE,Homestake) are obtained as a
function of the level of noise, regular magnetic field and neutrino mixing
parameters. Previous results obtained for small mixing and ad-hoc regular
magnetic profiles are reobtained. We find that
  MSW regions are stable up to very large levels of noise
  (P=0.7-0.8) and they are acceptable from the point of view of antineutrino
production. For strong noise any parameter region $(\Delta m^2, \sin^2
2\theta)$ is excluded: this model of noisy magnetic field is not compatible
with particle physics solutions to the SNP. scenario.


title: Renormalization group analysis of the QCD quark potential to order v^2

abstract:
  A one-loop renormalization group analysis of the order v^2 relativistic
corrections to the static QCD potential is presented. The velocity
renormalization group is used to simultaneously sum ln(m/mv) and ln(m/mv^2)
terms. The results are compared to previous calculations in the literature.


title: Ten Years of Precision Electroweak Physics

abstract:
  We review a number of theoretical developments in Precision Electroweak
Physics that are closely connected with the interpretation of experiments. The
emphasis is on the test of the Standard Model at the level of its quantum
corrections, the search for the Higgs boson, and constraints on new physics.


title:
The QED lowest-order radiative corrections to the two polarized
  identical fermion scattering

abstract:
  The explicit exact expressions of QED lowest-order radiative corrections to
the two polarized identical fermion scattering are presented in covariant form.
Polarization effects are treated in detail.
  The infrared divergence from the real photon emission is extracted by
covariant approach.
  Some numerical results for M{\o}ller scattering are given.


title: Langevin Interpretation of Kadanoff-Baym Equations

abstract:
  We show that the nonperturbative quantum transport equations, the
`Kadanoff-Baym equations', can be understood as the ensemble average over
stochastic equations of Langevin type. For this we couple a free scalar boson
quantum field to an environmental heat bath with some given temperature T. The
inherent presence of noise and dissipation related by the
fluctuation-dissipation-theorem guarantees that the modes or particles become
thermally populated on average in the long-time limit. This interpretation
leads to a more intuitive physical picture of the process of thermalization and
of the interpretation of the Kadanoff-Baym equations.


title: Rescattering Effects for (\epsilon'/\epsilon)

abstract:
  A calculation of the hadronic matrix elements for K\to\pi\pi including
\pi-\pi rescattering effects in a dispersion integral is presented. I study the
dependence of the results on the matching scale \mu and use them to calculate
the CP-parameter (\epsilon\prime/\epsilon). I find improved stability on the
matching scale and good agreement with the experimental results.


title: Three-flavor MSW solutions of the solar neutrino problem

abstract:
  We perform an updated phenomenological analysis of the
Mikheyev-Smirnov-Wolfenstein (MSW) solutions of the solar neutrino problem,
assuming oscillations between two and three neutrino families. The analysis
includes the total rates of the Homestake, SAGE, GALLEX, Kamiokande and
Super-Kamiokande experiments, as well as the day-night asymmetry and the 18-bin
energy spectrum of Super-Kamiokande. Solutions are found at several values of
the theta_{13} mixing angle. Among the most interesting features, we find that
solar neutrino data alone put the constraint theta_{13} < 55--59 deg at 95%
C.L., and that a fraction of the MSW solutions extends at and beyond maximal
(nu_1,nu_2) mixing (theta_{12} > pi/4), especially if the neutrino square mass
splitting is in its lower range (m^2_2-m^2_1 ~ 10^{-7} eV^2) and if theta_{13}
is nonzero. In particular, bimaximal (or nearly bimaximal) mixing is possible
for atmospheric and MSW solar neutrino oscillations within the stringent
reactor bounds on theta_{13}.


title:
Like-Sign W Boson Production at the LHC as a Probe of Double Parton
  Scattering

abstract:
  Double parton scattering, i.e. two parton hard scattering processes in the
same hadron-hadron collision, may constitute an important background for Higgs
and other new particle searches at the LHC. We point out that like-sign W pair
production provides a relatively clean way of searching for, and calibrating,
double parton scattering at the LHC.


title: Deep inelastic scattering, diffraction, and all that

abstract:
  These lectures include an introduction to the partonic description of the
proton, the photon and the `colour singlet', as seen in inclusive and
semi-inclusive DIS, in $e^+e^-$ collisions, and in diffractive processes,
respectively. Their formal treatment using structure, fragmentation, and
fracture functions is outlined giving an insight into the perturbative QCD
framework for these functions. Examples and comparisons with experimental data
from LEP, HERA, and Tevatron are also covered.


title: Finite-volume analysis of N_f-induced chiral phase transitions

abstract:
  In the framework of Euclidean QCD on a torus, we study the spectrum of the
Dirac operator through inverse moments of its eigenvalues, averaged over
topological sets of gluonic configurations. The large-volume dependence of
these sums is related to chiral order parameters. We sketch how these results
may be applied to lattice simulations in order to investigate the chiral phase
transitions occurring when N_f increases. In particular, we demonstrate how
Dirac inverse moments at different volumes could be compared to detect in a
clean way the phase transition triggered by the suppression of the quark
condensate and by the enhancement of the Zweig-rule violation in the vacuum
channel.


title: The t->cH decay width in the standard model

abstract:
  The t->cH decay width has been computed in the standard model with a light
Higgs boson. The corresponding branching fraction has been found to be in the
range B(t->cH) ~ 10^{-13} - 10^{-14} for M_Z < m_H < 2 M_W. Our results correct
the numerical evaluation usually quoted in the literature.


title:
MSSM Lightest CP-Even MSSM Higgs Boson Mass to O(alpha_s alpha_t): the
  Effective Potential Approach

abstract:
  Starting with the two-loop effective potential of the MSSM, and assuming a
supersymmetric scale well above $M_Z$, we derive a simple analytical
approximation for the lightest CP-even Higgs boson mass including resummation
of higher order logarithmic terms via RG-improvement and finite non-logarithmic
terms up to ${\cal O}(\alpha_s\alpha_t)$. This formula describes the most
relevant radiative corrections to the MSSM Higgs boson mass, in particular,
those associated with non-zero top-squark mixing.


title:
Multiplicity distributions in e+e- annihilation into hadrons and pure
  birth branching processes

abstract:
  Recursive solution for a general homogeneous in time pure birth branching
process with simultaneous production of any number of particles and with
continuous evolution parameter is given. Calculational algorithm based on the
use of Koenigs function and functional Schroder equation is described. It is
shown that multiplicity distributions in e+e- annihilation into hadrons for
c.m. energies up to 189 GeV are well described by the modified negative
binomial distribution, explained by simple pure birth branching process without
multiple simultaneous particle production. The energy dependence of the
evolution parameter is also discussed.


title: Zee Neutrino Mass Model in SUSY Framework

abstract:
  We study the Zee model of neutrino mass in the framework of R-parity
violating supersymmetry. Within the matter contents of the minimal
supersymmetric standard model, any one of the three right-handed sleptons could
be a suitable candidate for the charged-singlet scalar of the Zee model, and
one of the Higgs doublets provides the extra necessary vacuum expectation
value. A combination of one bilinear and two trilinear R-parity-violating
couplings then completes the model. In this framework, we also discuss other
various contributions to neutrino masses and derive the conditions for the
dominance of the contribution from the Zee model, and hence maintain the
successfully Zee mass texture. However, this model within the minimal
supersymmetric standard model is shown to be only marginally feasible. More
general versions of supersymmetrization of the Zee model are also discussed. A
particularly interesting example that has extra Higgs doublets while the
slepton, especially the selectron, keeps the role of the Zee scalar is
illustrated.


title:
3D-4D Interlinkage Of B-S Amplitudes : Unified View Of QQbar And QQQ
  Dynamics

abstract:
  This article has a 3-fold objective: i) to provide a panoramic view of
several types of 3D vs 4D approaches in Field Theory (Tamm-Dancoff, Bethe
Salpeter Equation (BSE), Quasi-potentials, Light-Front Dynamics, etc) for
strong interaction dunamics; ii) to focus on the role of the Markov-Yukawa
Transversality Principle (MYTP) as a novel paradigm for an exact 3D-4D
interlinkage between the corresponding BSE amplitudes; iii) Stress on a closely
parallel treatment of $q{\bar q}$ and qqq BSE's stemming from a common
4-fermion Lagrangian mediated by gluon (vector)-like exchange. The two-way
interlinkage offered by MYTP between the 3D and 4D BSE forms via a
Lorentz-covariant 3D support to the BS kernel, gives it a unique status which
distinguishes it from most other 3D approaches to strong interaction dynamics,
which give at most a one-way connection. Two specific types of MYTP which
provide 3D support to the BSE kernel, are considered: a) Covariant
Instantaneity Ansatz (CIA); b) Covariant LF/NP ansatz (Cov.LF). Both lead to
formaly identical 3D BSE reductions (thus ensuring common spectral
predictions), but their 4D manifestations differ sharply: Under CIA, the 4D
loop integrals suffer from Lorentz mismatch of the vertex functions, leading to
ill-defined time-like momentum integrals, but Cov LF is free from this disease.
Some practical uses of MYTP as a basis for evaluating various types of 4D loop
integrals are outlined. PACS: 11.10 st ; 12.38 Lg ; 13.40.Fn Keywords:
Tamm-Dancoff, Bethe-Salpeter, Quasi-potentials, Light-front (LF),
Markov-Yukawa, 3D-4D Interlinkage, CIA, Cov-LF, Spectroscopy.


title: Neutrino mixing scenarios and AGN

abstract:
  Active galactic nuclei (AGN) have been suggested to be sources of very high
energy neutrinos. We consider the possibility of using AGN neutrinos to test
neutrino mixings. From the atmospheric, solar and laboratory data on neutrino
oscillations we derive the flavour composition of the AGN neutrino flux in
different neutrino mixing schemes. We show that most of the schemes considered
can be distinguished from each other and the existence of a sterile neutrino
can be specially tested. AGN neutrinos can also be used to test those
four-neutrino scenarios where solar neutrinos oscillate into an arbitrary
mixture of $\nu_s$ and $\nu_\tau$.


title:
Renormalization-Scale-Invariant PQCD Predictions for R_e+e- and the
  Bjorken Sum Rule at Next-to-Leading Order

abstract:
  We discuss application of the physical QCD effective charge $\alpha_V$,
defined via the heavy-quark potential, in perturbative calculations at
next-to-leading order. When coupled with the Brodsky-Lepage-Mackenzie
prescription for fixing the renormalization scales, the resulting series are
automatically and naturally scale and scheme independent, and represent
unambiguous predictions of perturbative QCD. We consider in detail such
commensurate scale relations for the $e^+e^-$ annihilation ratio $R_{e^+e^-}$
and the Bjorken sum rule. In both cases the improved predictions are in
excellent agreement with experiment.


title: Impact of D0-D0bar mixing on the experimental determination of gamma

abstract:
  Several methods have been devised to measure the weak phase gamma using
decays of the type B+- --> D K+-, where it is assumed that there is no mixing
in the D0-D0bar system. However, when using these methods to uncover new
physics, one must entertain the real possibility that the measurements are
affected by new physics effects in the D0-D0bar system. We show that even
values of x_D and/or y_D around 10^{-2} can have a significant impact in the
measurement of sin^2{gamma}. We discuss the errors incurred in neglecting this
effect, how the effect can be checked, and how to include it in the analysis.


title: What is the Standard Model Higgs ?

abstract:
  It is shown that in the Standard Model, the property of charge quantization
holds for a Higgs with arbitrary isospin and hypercharge. These defining
quantum numbers of the Higgs remain unconstrained while the whole basic and
fundamental structure of the Standard Model remains intact. Hence it is shown
that the Higgs cannot be a physical particle. Higgs is the underlying `vacuum'
over which the whole edifice of the Standard Model stands.


title: Electric charge, early universe and the Superstring Theories

abstract:
  Very recently, it has been shown by the author that the Standard Model Higgs
cannot be a physical particle. Here, on most general grounds it is established
that as per the Standard Model there is no electric charge above the
electro-weak phase transition temperature. Hence there was no electric charge
present in the early universe. The Superstring Theories are flawed in as much
as they are incompatible with this requirement. Hence the Superstring Theories
are inconsistent with this basic structure and requirement of the Standard
Model.


title:
Regge-Eikonal Approach and its off-Shell Extention Versus Experimental
  Data

abstract:
  We develop an off-shell extention of the Regge-eikonal approach which
automatically takes into account off-shell unitarity. We argue that exclusive
vector-meson production cross-sections measured at HERA can be fairly described
with classical universal Regge trajectories. No extra ``hard'' trajectories of
high intercept are needed for that.


title:
On the K^+_- meson production from the quark-gluon plasma phase in
  ultra-relativistic heavy-ion collisions

abstract:
  An abundance of the strangeness that can be induced in a thermalized
quark-gluon plasma (QGP) is considered as a signal of the QGP phase appearing
in the intermediate state of ultra-relativistic heavy-ion collisions. As a
quantitative characteristic of this signal we take the ratio R_{K^+ K^-} =
N_{K^+}/N_{K^-} of the multiplicities of the production of K^+_- mesons. This
ratio is evaluated for a thermalized QGP phase of QCD and for the quark-gluon
system escaped from the QGP phase. For a thermalized QGP phase the ratio R_{K^+
K^-} has been found as a smooth function of a 3-momentum of the K^+_- mesons
and a temperature ranging the values from the region 160 MeV < T <200 MeV. We
show that at the temperature T= 175 MeV our prediction for the ratio
R_{K^+K^-}(q,T = 175) = 1.80^{+ 0.04}_{-0.18} agrees good with the experimental
data of NA49 and NA44 Collaborations on central ultra-relativistic Pb-Pb
collisions at 158 GeV per nucleon: R^{\exp}_{K^+K^-} = 1.80\pm 0.10. For the
ratio of the K^+ and \pi^+ multiplicities we have obtained the value
R_{K^+\pi^+}(q,T = 175) = 0.134\pm 0.014 agreeing good with the experimental
data of NA35 Collaboration on the nucleus-nucleus collisions at 200 GeV per
nucleon R^{\exp}_{K^+\pi^+} = 0.137\pm 0.008.


title: Imaginative Cosmology

abstract:
  We review a few off-the-beaten-track ideas in cosmology. They solve a variety
of fundamental problems; also they are fun. We start with a description of
non-singular dilaton cosmology. In these scenarios gravity is modified so that
the Universe does not have a singular birth. We then present a variety of ideas
mixing string theory and cosmology. These solve the cosmological problems
usually solved by inflation, and furthermore shed light upon the issue of the
number of dimensions of our Universe. We finally review several aspects of the
varying speed of light theory. We show how the horizon, flatness, and
cosmological constant problems may be solved in this scenario. We finally
present a possible experimental test for a realization of this theory: a test
in which the Supernovae results are to be combined with recent evidence for
redshift dependence in the fine structure constant.


title:
Description of the Proton Structure Function $F_2^p(x,Q^2)$ in the
  Framework of Extended Regge - Eikonal Approach

abstract:
  The proton structure function $F_2^p(x,Q^2)$ is described in the framework of
the off-shell extention of the Regge-eikonal approach which automatically takes
into account off-shell unitarity. We achieved a good quality of description for
$x<10^{-2}$ and we argue that the data on $F_2^p(x,Q^2)$ measured at HERA can
be fairly described with classical universal Regge trajectories. No extra,
``hard'' trajectories of high intercept are needed for that. The $x-, Q^2-$
slopes and the effective intercept are discussed as functions of $Q^2$ and $x$.


title: Upper limit on mh in the MSSM and M-SUGRA vs. prospective reach of LEP

abstract:
  The upper limit on the lightest CP-even Higgs boson mass, mh, is analyzed
within the MSSM as a function of tan(beta) for fixed mtop and Msusy. The impact
of recent diagrammatic two-loop results on this limit is investigated. We
compare the MSSM theoretical upper bound on mh with the lower bound obtained
from experimental searches at LEP. We estimate that with the LEP data taken
until the end of 1999, the region mh < 108.2 GeV can be excluded at the 95%
confidence level. This corresponds to an excluded region 0.6 <= tan(beta) <=
1.9 within the MSSM for mtop = 174.3 GeV and Msusy <= 1 TeV. The final
exclusion sensitivity after the end of LEP, in the year 2000, is also briefly
discussed. Finally, we determine the upper limit on mh within the Minimal
Supergravity (M-SUGRA) scenario up to the two-loop level, consistent with
radiative electroweak symmetry breaking. We find an upper bound of mh \approx
127 GeV for mtop = 174.3 GeV in this scenario, which is slightly below the
bound in the unconstrained MSSM.


title: Mass Effects in Bose Einstein Correlations

abstract:
  Bose-Einstein symmetrization can lead to correlations between out going
identical particles which reflect the space-time extent of the collision
process. At LEP and LEPII these correlations have been studied as a function of
a single variable Q, the invariant momentum separation. Assuming a simple form
for the correlation function the experiments find source radii dependent on the
hadron mass. In this note, I point out that such effects can arise from purely
kinematic considerations, although these are unlikely to explain the observed
effects completely.


title: The two-loop scalar and tensor pentabox graph with light-like legs

abstract:
  We study the scalar and tensor integrals associated with the pentabox
topology: the class of two-loop box integrals with seven propagators - five in
one loop and three in the other. We focus on the case where the external legs
are light-like and use integration-by-parts identities to express the scalar
integral in terms of two master-topology integrals and present an explicit
analytic expression for the pentabox scalar integral as a series expansion in
ep = (4-D)/2. We also give an algorithm based on integration by parts for
relating the generic tensor integrals to the same two master integrals and
provide general formulae describing the master integrals in arbitrary dimension
and with general powers of propagators.


title:
The R ratio in e+ e-, the determination of alpha(Mz^2) and a possible
  non-perturbative gluonic contribution

abstract:
  We review the determination of the QED coupling at the Z pole, which is a
crucial parameter for electroweak theory. We include recent e+e- -> hadron data
from Novosibirsk and Beijing to re-evaluate alpha (M_Z^2). We find 1/alpha
(M_Z^2) = 128.973 +/- 0.035 or 128.934 +/- 0.040 according, respectively, to
whether inclusive or exclusive e+e- -> hadron data are used in the interval 1.4
< \sqrt{s} < 2.1 GeV. The error is mainly due to uncertainties in the data in
the low energy region, \sqrt{s} < 2.5 GeV. We find that no advantage is
obtained by analytic continuation of the dispersion relation into the complex s
plane. We show that the hints of structure for \sqrt{s} ~ 2.5 GeV may be
evidence of a non-perturbative gluonic contribution to R(s).


title:
Loop-Induced CP Violation in the Gaugino and Higgsino Sectors of
  Supersymmetric Theories

abstract:
  We show that the gaugino and higgsino sectors of supersymmetric theories can
naturally acquire observable CP violation through radiative effects which
originate from large CP-violating trilinear couplings of the Higgs bosons to
the third-generation scalar quarks. These CP-violating loop effects are not
attainable by evolving the supersymmetric renormalization-group equations from
a higher unification scale down to the electroweak one. We briefly discuss the
phenomenological consequences of such a scenario, and as an example, calculate
the two-loop contribution to the neutron electric dipole moment generated by
the one-loop chromo-electric dipole moment of the gluino.


title:
Strong Isospin-Breaking Effects in K-->pi pi at Next-to-Leading Order in
  the Chiral Expansion

abstract:
  Strong isospin-breaking (IB) contributions to both the octet and 27-plet weak
K-->2 pi transitions are evaluated at next-to-leading order (NLO) in the chiral
expansion. NLO contributions are shown to significantly reduce the leading
order result for the potentially large contribution to the $\Delta I=3/2$
amplitude resulting from strong isospin-breaking modifications to the weak
Delta I=1/2 amplitude. The ratio of strong IB 27-plet to strong IB octet
contributions is found to be small for all decay amplitudes. Combined with
recent results on the corresponding electromagnetic contributions, we find that
the ratio of the intrinsic strengths of octet and 27-plet effective weak
operators can be taken to be that obtained from experimental data, analyzed
ignoring isospin breaking, to an accuracy better than of order 10 percent.


title: The Sinc Function Representation and Three-Loop Master Diagrams

abstract:
  We test the Sinc function representation, a novel method for numerically
evaluating Feynman diagrams, by using it to evaluate the three-loop master
diagrams. Analytical results have been obtained for all these diagrams, and we
find excellent agreement between our calculations and the exact values. The
Sinc function representation converges rapidly, and it is straightforward to
obtain accuracies of 1 part in 10^6 for these diagrams and with longer runs we
found results better than 1 part in 10^{12}. Finally, this paper extends the
Sinc function representation to diagrams containing massless propagators.


title: Multiquark picture for Lambda(1405) and Sigma(1620)

abstract:
  We propose a new QCD sum rule analysis for the Lambda(1405) and the
Sigma(1620). Using the I=0 and I=1 multiquark sum rules we predict their
masses.


title: Mass hierarchies and mixing angles

abstract: The paper has been withdrawn


title: NLO correction to one-particle inclusive production at high energies

abstract:
  Next-to-leading order correction to the one-particle inclusive cross section
in the framework of high energy factorization is calculated. Numerical results
for midrapidity region are compared with predictions of conventional
calculations based on collinear factorization.


title: Strangeness and Charm Signatures of the Quark-Gluon Plasma

abstract:
  Strangeness, charmonium and open charm yields in relativistic nucleus-nucleus
collisions are considered within statistical model approach as potential
signals of the quark-gluon plasma.


title: Supersymmetry versus precision experiments revisited

abstract:
  We study constraints on the supersymmetric standard model from the updated
electroweak precision measurements --- the Z-pole experiments and the $W$-boson
mass measurements. The supersymmetric-particle contributions to the universal
gauge-boson-propagator corrections are parametrized by the three oblique
parameters Sz, Tz and mw. The oblique corrections, the Zqq and Zll vertex
corrections, and the vertex and box corrections to the \mu-decay width are
separately studied in detail. We first study individual contribution from the
four sectors of the model, the squarks, the sleptons, the supersymmetric
fermions (charginos and neutralinos), and the supersymmetric Higgs bosons, to
the universal oblique parameters, where the sum of individual contributions
gives the total correction. We find that the light squarks or sleptons, whose
masses just above the present direct search limits, always make the fit worse
than that of the Standard Model (SM), whereas the light charginos and
neutralinos generally make the fit slightly better. The contribution from the
supersymmetric Higgs sector is found small. We then study the vertex/box
corrections carefully when both the supersymmetric fermions (-inos) and the
supersymmetric scalars (squarks and sleptons) are light, and find that no
significant improvement over the SM fit is achieved. The best overall fit to
the precision measurements are found when charginos of mass $\sim 100\gev$ with
a dominant wino-component are present and the doublet squarks and sleptons are
all much heavier. The improvement over the SM is marginal, however, where the
total \chi^2 of the fit to the 22 data points decreases by about one unit, due
mainly to a slightly better fit to the $Z$-boson total width.


title:
O(alpha) corrections to e+e- --> WW --> 4fermions(+gamma): first
  numerical results from RACOONWW

abstract:
  First numerical results of the Monte Carlo generator RACOONWW for e+e- --> WW
--> 4fermions(+gamma) in the electroweak Standard Model are presented. This
event generator is the first one that includes O(alpha) electroweak radiative
corrections in the double-pole approximation completely. We briefly describe
the strategy of the calculation and give numerical results for total cross
sections, including CC03, and various distributions.


title: Top production above threshold: Electroweak and QCD corrections combined

abstract:
  Top quark production in electron-positron annihilation is one of the
benchmark reactions at a future linear collider. Both electroweak and QCD
corrections are large, amounting to 10% or even more in specific kinematic
regions. In this note we present a method which allows to combine the dominant
terms from both sources, thus improving considerably the result based on a
simple addition of both corrections.


title: Higher-order results in the Higgs sector of the MSSM

abstract:
  We analyze the impact of the recent Feynman-diagrammatic (FD) two-loop
results for the mass of the lightest CP-even Higgs boson in the MSSM on the
theoretical upper bound for mh as a function of tan(beta). The results are
compared with previous results obtained by renormalization group (RG) methods.
The incorporation of dominant FD two-loop corrections into the decay width
\Gamma(h -> f \bar f) is also discussed.


title: pi^0-eta Mixing and CP Violation

abstract:
  We discuss $\pi^0$ -$\eta$ mixing and its implication for $\epsilon'/
\epsilon$ to next-to-leading order in the low-energy expansion. The big effect
due to $\eta$-$\eta'$ mixing is shown to be largely cancelled by other
contributions occurring at the same order in the chiral expansion.


title: Yukawa Hierarchies from Split Fermions in Extra Dimensions

abstract:
  We explore a mechanism for generating the Yukawa hierarchies by displacing
the left- and right-handed components of the Standard Model fermions in a
higher-dimensional space. We find a unique configuration of displacements which
fits all quark and lepton masses and mixing angles, with a prediction for the
strange quark mass m_s = 120 MeV.


title:
Single-Brane Cosmological Solutions with a Stable Compact Extra
  Dimension

abstract:
  We consider 5-dimensional cosmological solutions of a single brane. The
correct cosmology on the brane, i.e., governed by the standard 4-dimensional
Friedmann equation, and stable compactification of the extra dimension is
guaranteed by the existence of a non-vanishing \hat{T}^5_5 which is
proportional to the 4-dimensional trace of the energy-momentum tensor. We show
that this component of the energy-momentum tensor arises from the backreaction
of the dilaton coupling to the brane. The same positive features are exhibited
in solutions found in the presence of non-vanishing cosmological constants both
on the brane (\Lambda_{br}) and in the bulk (\Lambda_B). Moreover, the
restoration of the Friedmann equation, with the correct sign, takes place for
both signs of $\Lambda_B$ so long as the sign of $\Lambda_{br}$ is opposite
$\Lambda_B$ in order to cancel the energy densities of the two cosmological
constants. We further extend our single-brane thin-wall solution to allow a
brane with finite thickness.


title: Hydrodynamics of nuclear matter in the chiral limit

abstract:
  Using the Poisson bracket method, we construct the hydrodynamics of nuclear
matter in the chiral limit, which describes the dynamics of all low-energy
degrees of freedom, including the fluid-dynamical and pionic ones. The
hydrodynamic equations contain, beside five Euler equations of relativistic
fluid dynamics, Nf^2-1 second order equations describing propagating pions and
Nf^2-1 first order equations describing the advection of the baryonic vector
isospin charges. We present hydrodynamic arguments showing that the pion
velocity vanishes at the second order phase transition at Nf=2.

categories: hep-ph cond-mat.soft nlin.CD nucl-th physics.flu-dyn


title: Pseudo-Dirac Neutrinos

abstract:
  We propose a scheme in which a pseudo-Dirac structure for three family of
light neutrinos is generated naturally. An extended Higgs sector with a majoron
is used for the generation of the leptonic number violating neutrino Majorana
mass. The resultant neutrino mass matrix could easily fit all available
experimental data. We discuss relevant constraints on the scales involved for
the model to be phenomenologically viable.


title: Low energy effects of Higgs induced leptoquark-diquark mixing

abstract:
  In low energy phenomenology to avoid the strong constraints of proton decay
it is usually assumed that light ($\approx $ 250 Gev) leptoquarks couple only
to quark-lepton pairs and light diquarks couple only to quark pairs. In this
work we show that the SM Higgs boson could induce a mixing between leptoquarks
and diquarks through trilinear interaction terms which reintroduces the
troublesome couplings and lead to proton decay. The bound on the unknown
parameters of this scenario that arise from proton life time has also been
derived.


title:
Phenomenon of the time-reversal violating magnetic field generation by a
  static electric field in a medium and vacuum

abstract:
  It is shown that the T- and P-odd weak interactions yield to the existence of
both electric field and magnetic (directed along the electric field) field
around an electric charge. Similarly the assotiated magnetic field is directed
along the vector of strength of stationary gravitational field.


title: Analytical Study of Non-Universality of the Soft Terms in the MSSM

abstract:
  We obtain general analytical forms for the solutions of the one-loop
renormalization group equations in the top/bottom/$\tau$ sector of the MSSM.
These solutions are valid for any value of $\tan \beta$ as well as any
non-universal initial conditions for the soft SUSY breaking parameters and
non-unification of the Yukawa couplings. We establish analytically a generic
screening effect of non-universality, in the vicinity of the infrared quasi
fixed point, which allows to determine sector-wise a hierarchy of sensitivity
to initial conditions. We give also various numerical illustrations of this
effect away from the quasi fixed point and assess the sensitivity of the Higgs
and sfermion spectra to the non-universality of the various soft breaking
sectors. As a by-product, a typical anomaly-mediated non-universality of the
gaugino sector would have marginal influence on the scalar spectrum.


title:
Search and identification of Scalar and Vector Leptoquarks at HERA with
  polarization

abstract:
  We analyze the effects of Scalar and Vector Leptoquarks on various
observables in electron (positron) - proton deep inelastic scattering. In view
of the future program of the HERA collider, with a high luminosity and also
with polarization, we present the constraints that can be reached using this
facility for several Leptoquark scenarios. We address the question of the
identification of the nature of a discovered Leptoquark. We emphasize the
relevance of having polarized lepton and proton beams in order to disentangle
completely the various Leptoquark models. This study is also relevant in the
context of the TESLA$\times$HERA project.


title:
A Nonperturbative Study of Inverse Symmetry Breaking at High
  Temperatures

abstract:
  The optimized linear $\delta$-expansion is applied to multi-field $O(N_1)
\times O(N_2)$ scalar theories at high temperatures. Using the imaginary time
formalism the thermal masses are evaluated perturbatively up to order
$\delta^2$ which considers consistently all two-loop contributions. A
variational procedure associated with the method generates nonperturbative
results which are used to search for parameters values for inverse symmetry
breaking (or symmetry nonrestoration) at high temperatures. Our results are
compared with the ones obtained by the one-loop perturbative approximation, the
gap equation solutions and the renormalization group approach, showing good
agreement with the latter method. Apart from strongly supporting inverse
symmetry breaking (or symmetry nonrestoration), our results reveal the
possibility of other high temperature symmetry breaking patterns for which the
last term in the breaking sequence is $O(N_1-1) \times O(N_2-1)$.


title: Slowing Out of Equilibrium Near the QCD Critical Point

abstract:
  The QCD phase diagram may feature a critical end point at a temperature T and
baryon chemical potential $\mu$ which is accessible in heavy ion collisions.
The universal long wavelength fluctuations which develop near this Ising
critical point result in experimental signatures which can be used to find the
critical point. The magnitude of the observed effects depends on how large the
correlation length $\xi$ becomes. Because the matter created in a heavy ion
collision cools through the critical region of the phase diagram in a finite
time, critical slowing down limits the growth of $\xi$, preventing it from
staying in equilibrium. This is the fundamental nonequilibrium effect which
must be calculated in order to make quantitative predictions for experiment. We
use universal nonequilibrium dynamics and phenomenologically motivated values
for the necessary nonuniversal quantities to estimate how much the growth of
$\xi$ is slowed.


title: Erraticity of Rapidity Gaps

abstract:
  The use of rapidity gaps is proposed as a measure of the spatial pattern of
an event. When the event multiplicity is low, the gaps between neighboring
particles carry far more information about an event than multiplicity spikes,
which may occur very rarely. Two moments of the gap distrubiton are suggested
for characterizing an event. The fluctuations of those moments from event to
event are then quantified by an entropy-like measure, which serves to describe
erraticity. We use ECOMB to simulate the exclusive rapidity distribution of
each event, from which the erraticity measures are calculated. The dependences
of those measures on the order of $q$ of the moments provide single-parameter
characterizations of erraticity.


title:
Searching for Extra Dimensions and New String-Inspired Forces in the
  Casimir Regime

abstract:
  The appearance of new fundamental forces and extra-dimensional modifications
to gravity in extensions of the Standard Model has motivated considerable
interest in testing Newtonian gravity at short distances (<10^-3 m). Presently
a number of new gravity experiments are searching for non-Newtonian effects in
the ranges 10^-4 m -- 10^-3 m. However, as challenging as these experiments
are, formidable new obstacles await the next generation of experiments which
will probe gravity at distances <10^-4 m where Casimir/van der Waals forces
become dominant. Here we will review the motivation for conducting such very
short distance gravity experiments, and discuss some of the new problems that
may arise in future experiments. Finally, we suggest schematic designs for null
experiments which would address some of these problems using the
``iso-electronic'' and ``finite-size'' effects.


title:
Associated production of Higgs bosons and heavy quarks at photon
  colliders

abstract:
  The idea of fermion mass generation through Yukawa couplings between Higgs
bosons and fermions may be tested by their associated production at future
linear colliders (LC). We study the production mechanism in the minimal
supersymmeric standard model at photon colliders that can be realized by the
laser back-scattering technique at the LC. We find that the cross sections for
the production of the light Higgs-top pair, heavy Higgs-bottom pair and
pseudoscalr Higgs-bottom pair can reach the level of \sim 1.0 fb or higher for
phenomenologically favoured values of the parameters in the Higgs sector. Since
this mechanism is not affected by the appearance of Higgs resonances as in
electron collisions, it may provide a more sensitive way to determine the
Yukawa couplings between Higgs bosons and heavy quarks.


title: CP Violating Bubble Wall Profiles

abstract:
  We solve the equations of motion for a CP violating phase between the two
Higgs doublets at the bubble wall of the MSSM electroweak phase transition.
Contrary to earlier suggestions, we do not find indications of spontaneous
``transitional'' CP violation in the MSSM. On the other hand, in case there is
explicit CP violation in the stop and chargino/neutralino sectors, the relative
phase between the Higgses does become space dependent, but only mildly even in
the maximal case. We also demonstrate that spontaneous CP violation within the
bubble wall could occur, e.g., if the Higgs sector of the MSSM were
supplemented by a singlet. Finally we point out some implications for
baryogenesis computations.


title: Recent Developments in Physics Beyond the Standard Model

abstract:
  In this talk I discuss some recent developments in physics beyond the
Standard Model. After some initial comments on neutrino masses, I discuss the
status of low-energy supersymmetry and finally turn to describing some recent
work in theories with extra spatial dimensions. Plenary talk at the XIX
International Symposium on Lepton and Photon Interactions at High Energies,
Stanford University, 9-14 August 1999.


title: Whither Hadron Supersymmetry?

abstract:
  A dynamically broken hadron supersymmetry appears to exist as a consequence
of QCD. The reasons for the supersymmetry appear most transparently in the
framework of the constituent quark model with a diquark approximation to two
quarks. Applications of the supersymmetry have led to relations between meson
and baryon masses and to predictions that certain kinds of exotic hadrons
should not be observed. I summarize the successful applications and discuss
possible future directions for this research.


title:
A systematic analysis of new physics effects in spin correlations in q
  qbar to t tbar

abstract:
  I show that there are eight new physics operators that contribute to top pair
production and subsequent decay in interference with the leading SM process at
the Tevatron and estimate their expected statistical inaccuracies. All fully
differential cross sections are calculated in the {6-particle} phase space. The
observation of angular correlations dramatically improves the accuracy of the
extraction.


title: Impact of radiative corrections on sterile neutrino scenarios

abstract:
  In sterile neutrino scenarios, radiative corrections induce mass splittings
proportional to the top Yukawa coupling, in contrast to the three active
neutrino case where the induced splittings are proportional to the tau Yukawa
coupling. In view of this, we have analyzed the stability of the four-neutrino
schemes favored by oscillation experiments, consisting in two pairs of nearly
degenerate neutrinos separated by the LSND gap. Requiring compatibility with
the measurements of the abundances of primordial elements produced in Big Bang
Nucleosynthesis, we find that when the heaviest pair corresponds to the solar
neutrinos (mainly an admixture of nu_e - nu_s) the natural mass splitting is
3-5 orders of magnitude larger than the observed one, discrediting the scenario
from a theoretical point of view. On the contrary, the scheme where the
heaviest pair corresponds to the atmospheric neutrinos (mainly an admixture of
nu_mu - nu_tau) is safe from radiative corrections due to the small sterile
component of these mass eigenstates.


title: Large-x Parton Distributions

abstract:
  Reliable knowledge of parton distributions at large x is crucial for many
searches for new physics signals in the next generation of collider
experiments. Although these are generally well determined in the small and
medium x range, it has been shown that their uncertainty grows rapidly for x >
0.1. We examine the status of the gluon and quark distributions in light of new
questions that have been raised in the past two years about large-x parton
distributions, as well as recent measurements which have improved the parton
uncertainties. We perform several specific global fits to answer the
outstanding questions, and to investigate the potential of future experiments,
particularly at HERA, which may provide critical constraints on parton
distributions at large x.


title: Explicit Calculation Of the Running Coupling BFKL Anomalous Dimension

abstract:
  I calculate the anomalous dimension governing the Q^2 evolution of the gluon
(and structure functions) coming from the running coupling BFKL equation. This
may be expressed in an exact analytic form, up to a small ultraviolet
renormalon contribution, and hence the corresponding splitting function may be
determined precisely. Rather surprisingly it is most efficient to expand the
gluon distribution in powers of alpha_s(Q^2) rather than use the traditional
expansion where all orders of alpha_s\ln(1/x) are kept on an equal footing. The
anomalous dimension is very different from that obtained from the fixed
coupling equation, and leads to a powerlike behaviour for the splitting
function as x ->0 which is far weaker, i.e. about x^(-0.2). The NLO corrections
to the anomalous dimension are rather small, unlike the fixed coupling case,
and a stable perturbative expansion is obtained.


title: Decay Constant of Pseudoscalar Meson in the Heavy Mass Limit

abstract:
  The leptonic decay constant of the pseudoscalar mesons a calculated by use of
the relativistic constituent quark model constructed on the point form of
Poincare-covariant quantum mechanics. We discuss the role relativistic
corrections for decay constants of pseudoscalar mesons with heavy quarks. We
consider the heavy mass limit of decay constant for two-particle system with
equal masses.


title: Leptonic Decays of Mesons in a Poincare- Covariant of a Quark Model

abstract:
  Using a relativistic constituent quark model based on point form of
relativistic quantum mechanics with given set of degrees of freedom we
investigate electroweak decays of the pion and rho mesons. All free parameters
of quark model (the mass u(d) -quark and parameters which determines the
confinement scale) are fixed by using relevant experimental data


title: Looking For TeV-Scale Strings and Extra-Dimensions

abstract:
  In contrast to the old heterotic string case, the (weakly coupled) type I
brane framework allows to have all, part or none of the standard model gauge
group factors propagating in large extra--dimensions of TeV$^{-1}$ size. We
investigate the main experimental signatures of these possibilities, related to
the production of Kaluza-Klein excitations of gluons and electroweak gauge
bosons. A discovery through direct observation of resonances is possible only
for compactification scales below 6 TeV. However effects due to exchange of
virtual Kaluza-Klein excitations could be observed for higher scales. We find
that LHC can probe compactification scales as high as 20 TeV for excitations of
gluons and 8-15 TeV for excitations of electroweak gauge bosons. Finally, in
the case where no gauge boson feels the extra-dimension, we find that effective
contact interactions due to massive string mode oscillations dominate those due
to the exchange of Kaluza-Klein excitations of gravitons and could be used to
obtain bounds on the string scale.


title: Lattice Calculations and Hadron Physics

abstract:
  We review progress in lattice QCD, focusing on efforts to calculate weak
matrix elements relevant for the determination of the Cabibbo-Kobayashi-Maskawa
matrix. Topics we discuss include light hadron spectrum and quark masses,
CP-violation in K meson decays and weak matrix elements of heavy-light mesons.


title: Quark Orbital Angular Momentum from Lattice QCD

abstract:
  We calculate the quark orbital angular momentum of the nucleon from the quark
energy-momentum tensor form factors on the lattice. The disconnected insertion
is estimated stochastically which employs the $Z_2$ noise with an unbiased
subtraction. This reduced the error by a factor of 4 with negligible overhead.
The total quark contribution to the proton spin is found to be $0.30 \pm 0.07$.
  From this and the quark spin content we deduce the quark orbital angular
momentum to be $0.17 \pm 0.06$ which is $\sim 34$% of the proton spin. We
further predict that the gluon angular momentum to be $0.20 \pm 0.07$, i. e.
$\sim$ 40% of the proton spin is due to the glue.


title: Four-fermion production with RACOONWW

abstract:
  RACOONWW is an event generator for e+e- --> WW --> 4fermions(+gamma) that
includes full tree-level predictions for e+e- --> 4f and e+e- --> 4f+gamma as
well as O(alpha) corrections to e+e- --> 4f in the so-called double-pole
approximation. We briefly sketch the concept of the calculation on which this
generator is based and present some numerical results.


title: The crucial problem: the electroweak symmetry breaking

abstract:
  1. Why we do Believe in the Standard Model
  2. Why we do not Believe in the Standard Model
  2.1 Conceptual Problems
  2.2 Hints from Experiment
  2.2.1 Unification of Couplings
  2.2.2 Dark Matter
  2.2.3 Neutrino Masses
  2.2.4 Baryogenesis
  3. Status of the Search for the Higgs and for New Physics
  4. Conclusion


title: Fragmentation and Hadronization

abstract:
  Experimental data, theoretical ideas and models concerning jet fragmentation
and the hadronization process are reviewed, concentrating on the following
topics: factorization and small-x resummation of fragmentation functions,
hadronization models, single-particle yields and spectra in Z decay,
comparisons between quark and gluon jets, current and target fragmentation in
deep inelastic scattering, heavy quark fragmentation, Bose-Einstein
correlations and WW fragmentation.


title: Theta angle versus CP violation in the leptonic sector

abstract:
  Assuming that the axion mechanism of solving the strong CP problem does not
exist and the vanishing of theta at tree level is achieved by some
model-building means, we study the naturalness of having large CP-violating
sources in the leptonic sector. We consider the radiative mechanisms which
transfer a possibly large CP-violating phase in the leptonic sector to the
theta parameter. It is found that large theta cannot be induced in the models
with one Higgs doublet as at least three loops are required in this case. In
the models with two or more Higgs doublets the dominant source of theta is the
phases in the scalar potential, induced by CP violation in leptonic sector.
Thus, in the MSSM framework the imaginary part of the trilinear soft-breaking
parameter A_l generates the corrections to the theta angle already at one loop.
These corrections are large, excluding the possibility of large phases, unless
the universality in the slepton sector is strongly violated.


title: Tau Physics

abstract:
  The pure leptonic or semileptonic character of tau decays makes them a good
laboratory to test the structure of the weak currents and the universality of
their couplings to the gauge bosons. The hadronic $\tau$ decay modes constitute
an ideal tool for studying low--energy effects of the strong interactions in
very clean conditions. New physics phenomena, such as a non-zero $m_{\nu_\tau}$
or violations of conservation laws can also be searched for with tau decays.
The present experimental and theoretical status of tau physics is summarized.


title:
Neutrino oscillations with three flavors in matter: Applications to
  neutrinos traversing the Earth

abstract:
  Analytic formulas are presented for three flavor neutrino oscillations in
matter in the plane wave approximation. We calculate in particular the time
evolution operator in both mass and flavor bases. We also find the transition
probabilities expressed as functions of the vacuum mass squared differences,
the vacuum mixing angles, and the matter density parameter. The application of
this to neutrino oscillations for both atmospheric and long baseline neutrinos
in a mantle-core-mantle step function model of the Earth's matter density
profile is discussed.


title: Electroweak characteristics of mesons in the relativistic quark model

abstract:
  In this work the electromagnetic radius and the polarizability of the mesons
are obtained by use of the effective Lagrangians constructed on the one hand
with taking into account of general principles of the relativistic quantum
field theory and on the other hand with taking into account of the compound
relativistic model meson representation. Also using a relativistic constituent
quark model based on point form of Poincare-covariant quantum mechanics we
calculated electromagnetic radius and the decay constants of the mesons with
spinor quarks.