title:
Probing the CP of the Higgs at a $\gamma \gamma$ collider using $\gamma
  \gamma \to t \bar t \to lX$

abstract:
  We present results of an investigation to study CP violation in the Higgs
sector in $t\bar t$ production at a $\gamma\gamma$-collider. This is done in a
model independent way in terms of six form-factors $\{\Re(S_{\gamma}),
\Im(S_{\gamma}), \Re(P_{\gamma}), \Im(P_{\gamma}), S_t, P_t\}$ which
parameterize the CP mixing in Higgs sector. The angular distribution of the
decay lepton from $t/\bar t$ is shown to be independent of any CP violation in
the $tbW$ vertex. Hence it can be used as a diagnostic of the CP mixing. We
study how well one can probe different combinations of the form factors by
measurements of the combined asymmetries that we construct, in the initial
state lepton (photon) polarization and the final state lepton charge, using
only circularly polarized photons. We show that the method can be sensitive to
loop-induced CP violation in the Higgs sector in the MSSM.


title: The strong coupling constant at small momentum as an instanton detector

abstract:
  We present a study of $\alpha_{MOM}(p)$ at small p computed from the lattice.
It shows a dramatic $\propto p^4$ law which can be understood within an
instanton liquid model. In this framework the prefactor gives a direct measure
of the instanton density in thermalised configurations. A preliminary result
for this density is 5.27(4) fm^{-4}.


title:
Gap equations and effective potentials at finite temperature and
  chemical potential in D dimensional four-fermion models

abstract:
  We have proven the general relations between the gap equations obeyed by
dynamical fermion mass and corresponding effective potentials at finite
temperature and chemical potential in D dimensional four-fermion interaction
models. This gives an easy approach to get effective potentials directly from
the gap equations. We find out explicit expressions for the effective
potentials at zero temperature in the cases of $D=2,3$ and 4 for practical use.


title: Absolute neutrino mass update

abstract:
  The determination of absolute neutrino masses is crucial for the
understanding of theories underlying the standard model, such as SUSY. We
review the experimental prospects to determine absolute neutrino masses and the
correlations among approaches, using the Delta m^2's inferred from neutrino
oscillation experiments and assuming a three neutrino Universe.


title:
Four-Zero Texture of Hermitian Quark Mass Matrices and Current
  Experimental Tests

abstract:
  We show that the four-zero texture of Hermitian quark mass matrices can
survive current experimental tests: it is able to yield sufficiently large
predictions for the flavor mixing parameter $|V_{ub}/V_{cb}|$ and the
CP-violating parameter $\sin 2\beta$, without fine-tuning of the input values
of quark masses, provided the (2,2), (2,3) and (3,3) elements of up and down
mass matrices roughly satisfy a geometrical hierarchy. The successful relations
$|V_{us}| \approx \sqrt{m_u/m_c + m_d/m_s}$ and $|V_{td}/V_{ts}| \approx
\sqrt{m_d/m_s}$ obtained previously from the six-zero texture of Hermitian
quark mass matrices remain unchanged in the new ansatz.


title:
Renormalization of Hamiltonian Field Theory; a non-perturbative and
  non-unitarity approach

abstract:
  Renormalization of Hamiltonian field theory is usually a rather painful
algebraic or numerical exercise. By combining a method based on the coupled
cluster method, analysed in detail by Suzuki and Okamoto, with a Wilsonian
approach to renormalization, we show that a powerful and elegant method exist
to solve such problems. The method is in principle non-perturbative, and is not
necessarily unitary.


title: String corrections to gauge couplings from a field theory approach

abstract:
  An effective field theory approach is introduced to compute one-loop
radiative corrections to the gauge couplings due to Kaluza-Klein states
associated with a two-torus compactification. The results are compared with
those of the string in the field theory ``limit'' alpha'-> 0. The whole U and
the leading T moduli dependence of the gauge dependent part of the string
corrections to gauge couplings can be recovered using the effective field
theory approach.


title:
On the equivalence between the Boltzmann equation and classical field
  theory at large occupation numbers

abstract:
  We consider a system made up of exictations of a neutral scalar field, \phi,
having a \lambda\phi^4 interaction term. Starting from an ensemble where the
occupation number f is large, but \lambda f is small, we develop a classical
field theory description of the evolution of the system toward equilibrium. A
Boltzmann equation naturally emerges in this description and we show by
explicit calculation that the collision term is the same as that coming from
elastic scattering. This shows the equivalence of a Boltzmann equation
description and a classical field theory description of the same system.


title:
Calculable Corrections to Brane Black Hole Decay II: Greybody Factors
  for Spin 1/2 and 1

abstract:
  The production of black holes in extra-dimensional brane-world theories can
lead to detectable signals via the Hawking evaporation of the black hole to
brane-localised Standard Model modes. We calculate, as a function of partial
wave number and number of toroidally compactified extra dimensions, the leading
correction to the energy spectrum of such Hawking radiation (the greybody
factors) for decay into spin 1/2 fermions and spin 1 gauge fields localised on
the Standard Model brane. We derive the associated improved differential
emission rates for both types of fields. We provide both simple expressions for
the leading behavior of the greybody factors in the low-energy limit $\om r_H
\ll 1$, and numerical evaluation of our full analytic expressions for the
emission rates, valid for $\om r_H \sim 1$. The full analytic expressions
demonstrate that both the greybody factors and emission rates are enhanced as
the number of extra dimensions increases.


title: Kinetics of Vacuum Pair Creation in Strong Electromagnetic Fields

abstract:
  We study particle - antiparticle pair production under action of a strong
time dependent space homogeneous electric field at the presence of a collinear
constant magnetic field. We derive the kinetic equation for a such field
configuration for fermions and bosons in the framework of the Schwinger
mechanism of vacuum tunneling. We show the enhancement of pair production for
fermions with the increasing of the magnetic field as in the case of the
constant electromagnetic field. We have constructed closed set of equations,
which can be applied to some actual problems with manifestation of strong
electromagnetic fields, e.g., it is essential in the framework of the Flux Tube
Model of Quark - Gluon Plasma generation; for describing some cosmological
objects and especially because of the planned experiments on creation of
subcritical fields in the X-Free Electron Laser pulses.


title:
In-medium spectral change of omega mesons as a probe of QCD four-quark
  condensate

abstract:
  Within QCD sum rules at finite baryon density we show the crucial role of
four-quark condensates for the in-medium modification of the omega meson
spectral function. In particular, such a global property as the sign of the
in-medium omega meson mass shift is found to be governed by a parameter which
describes the strength of the density dependence of the four-quark condensate
beyond mean-field approximation. To study self-consistently the broadening of
the omega meson resonance we employ a hadron spectral function based on the
omega meson propagator delivered by an effective chiral Lagrangian.
Measurements of the omega meson spectral change in heavy-ion collisions with
the HADES detector can reveal the yet unknown density dependence of the
four-quark condensate.


title: Determining the oscillation parameters by Solar neutrinos and KamLAND

abstract:
  The neutrino oscillation experiment KamLAND has given the first evidence for
disappearance of $\bar \nu_e$ coming from nuclear reactors. We have combined
their data with all the solar neutrino data assuming two flavor neutrino mixing
and obtained allowed parameter regions which are compatible with the so-called
large mixing angle MSW solution to the solar neutrino problem. The allowed
regions in the plane of mixing angle and mass squared difference are now split
into two islands at 99% C.L. We have speculated how these two islands can be
separated in the near future. We have shown that a 50% reduction of the error
on SNO neutral-current measurement can be important in establishing in each of
these islands the true values of these parameters lie. We also have simulated
KamLAND positron energy spectrum after 1 year of data taking, assuming the
current best fitted values of the oscillation parameters, combined it the with
current solar neutrino data and showed how these two split islands can be
modified.


title: Recent Results on Quarkonium Production and Decay

abstract:
  I summarize the current status of the comparison between experiment and the
predictions of the NRQCD factorization approach to quarkonium decay and
production. I also present the results of some recent calculations and
theoretical developments in the NRQCD factorization approach.


title: Supersymmetry: the Next Spectroscopy

abstract:
  I describe the picture by which supersymmetry--the possible symmetry of
Nature that converts fermions to bosons and vice versa--accounts for the next
stage of physics beyond the Standard Model. I then survey the future
experimental program implied by this theory, in which the spectrum of particles
associated with supersymmetry will be determined with precision. [Invited
lecture at the Werner Heisenberg Centennial Symposium, December, 2001.]


title: Low energy constraints on orbifold models

abstract:
  We review the low energy limits on Kaluza-Klein excitations in orbifold
models. New vector-like quarks, as well as new Z' gauge bosons, can be
accommodated with masses observable at large colliders.


title: Magnetic Wall From Chiral Phase Transition and CMBR Correlations

abstract:
  Possible CMBR correlations are estimated with a model in which a Hubble-size
magnetic wall is formed during the QCD chiral phase transition. Measurable
polarization correlations are found for l greater than 1000. Metric
perturbations from the wall were found to give rise to observable correlations.


title: The onset of e^+e^- -> tau^+ tau^- at threshold revisited

abstract:
  The precise knowledge of the onset of the cross section $\sigma(e^+e^- \to
\tau^+\tau^-)$ at the threshold is necessary for improving the accuracy of
determination of the $\tau$ mass from the threshold measurements. The QED
radiative corrections of relative order $\alpha$ and $\alpha^2$, additional to
the well known Coulomb factor, are considered in the threshold region. The
correction terms of order $\alpha^2$ are calculated, which contain coefficients
enhanced by large parameters. As a result it is argued that the known
$O(\alpha)$ corrections provide the accuracy of the description of the cross
section close to $10^{-4}$, rather than $10^{-3}$ as claimed in a recent
literature. Also analytical expressions are provided for some limiting cases of
the corrections, previously calculated numerically.


title: Coarse graining and a new strategy for renormalization

abstract:
  We present the natural arguments for the rationality of a recently proposed
simple approach for renormalization which is based solving differential
equations. The renormalization group equation is also derived in a natural way
and recognized as a decoupling theorem of the UV modes that underlie a QFT.
This new strategy has direct implications to the scheme dependence problem.


title: Comparison of SANC with KORALZ and PHOTOS

abstract:
  Using the SANC system we study the one-loop electroweak standard model
prediction, including virtual and real photon emissions, for the decays of
on-shell vector and scalar bosons B --> f anti-f (gamma), where B is a vector
boson, Z or W, or a Standard Model Higgs. The complete one-loop corrections and
exact photon emission matrix element are taken into account. For the
phase-space integration, the Monte Carlo technique is used. For Z decay the QED
part of the calculation is first cross-checked with the exact one-loop QED
prediction of KORALZ. For Higgs boson and W decays, a comparison is made with
the approximate QED calculation of PHOTOS Monte Carlo. This provides a useful
element for the evaluation of the theoretical uncertainty of PHOTOS, very
interesting for its application in ongoing LEP2 and future LC and LHC
phenomenology.


title: Some Unsettled Questions in the Problem of Neutrino Oscillations

abstract:
  It is noted that the theory of neutrino oscillations can be constructed only
in the framework of the particle physics theory, where is a mass shell
conception and then transitions (oscillations) between neutrinos with equal
masses are real and between neutrinos with different masses are virtual. It is
necessary to solve the question: which type of neutrino transitions
(oscillations) is realized in nature? There can be three types of neutrino
transitions (oscillations). At present it is considered that Dirac and Majorana
neutrino oscillations can be realized. It is shown that we cannot put Majorana
neutrinos in the standard weak interactions theory without violation of the
gauge invariance. Then it is obvious that there can be only realized
transitions (oscillations) between Dirac neutrinos with different flowers. Also
it is shown that the mechanism of resonance enhancement of neutrino
oscillations in matter cannot be realized without violation of the law of
energy-momentum conservation. Though it is supposed that we see neutrino
oscillations in experiments, indeed there only transitions between neutrinos
are registered. In order to register neutrino oscillations it is necessary to
see second or even higher neutrino oscillation modes in experiments. For this
purpose we can use the elliptic character of the Earth orbit. The analysis
shows that the SNO experimental results do not confirm smallest of nu_e to
nu_\tau transition angle mixings, which was obtained in CHOOZ experiment. It is
also noted that there is contradiction between SNO, Super-Kamiokande, Homestake
and the SAGE and GNO (GALLEX) data.


title: Lepton flavor violation two-body decays of quarkoniums

abstract:
  In this paper we firstly study various model-independent bounds on lepton
flavor violation (LFV) in processes of $J/\Psi$, $\Psi'$ and $\Upsilon$
two-body decays, then calculate their branch ratios % By using the constraints
from other ways, we obtain %the indirect bounds of ${\rm Br}
(J/\Psi,\Psi',\Upsilon \to ll')$ in models of the leptoquark, $R$ violating
MSSM and topcolor assisted technicolor(TC2) models.


title: Neutrino mass parameters from Kamland, SNO and other solar evidence

abstract:
  An updated analysis of all available neutrino oscillation evidence in Reactor
(Kamland, first 145 days of data) and Solar experiments (SK day and night
spectra, global rates from
  Homestake, SAGE and GALLEX) including the $SNO CC$ and $NC$ data is
presented. In the framework of two active neutrino oscillations we determine
the allowed regions in neutrino parameter space, we obtain, from the Kamland
spectral shape and global signal, the following antineutrino best solution
parameters, $ \Delta m^2_{kl}= 7.7\times 10^{-5} \eV^2, \tan^2\theta_{kl}=
0.98.$ The overall effect of the measured observed ratio $R\sim 0.6$ is that
the LMA region remains the only one which is still favored.
  Combining Kamland and Solar data and assuming CPT invariance, i.e. the same
mass matrix for neutrino and antineutrinos, we obtain the following
antineutrino best solution parameters (LMAI solution), $ \Delta m^2= 7.1\times
10^{-5} \eV^2,\tan^2\theta= 0.47.$ A second solution (LMAII) appears for values
$ \Delta m^2= 1.5\times 10^{-4} \eV^2, \tan^2\theta= 0.48.$ We determine
additionally individual neutrino mixing parameters and their errors from fits
to marginal likelihood distributions, the values are compatible with previous
results. In both methods, $\chi^2$ minimization and marginal likelihood, the
combined analysis of solar and Kamland data concludes that maximal mixing is
not favored at the $\sim 3\sigma $ level at least.


title: Curvaton Reheating in Non-oscillatory Inflationary Models

abstract:
  In non-oscillatory (NO) inflationary models, the reheating mechanism was
usually based on gravitational particle production or the mechanism of instant
preheating. In this paper we introduce the curvaton mechanism into NO models to
reheat the universe and generate the curvature perturbation. Specifically we
consider the Peebles-Vilenkin quintessential inflation model, where the
reheating temperature can be extended from 1MeV to $10^{13}$GeV.


title:
A Supersymmetric Model with the Gauge Symmetry SU(3)_1 X SU(2)_1 X
  U(1)_1 X SU(3)_2 X SU(2)_2 X U(1)_2

abstract:
  A supersymmetric model with two copies of the Standard Model gauge groups is
constructed in the gauge mediated supersymmetry breaking scenario. The
supersymmetry breaking messengers are in a simple form. The Standard Model is
obtained after first step gauge symmetry breaking. In the case of one copy of
the gauge interactions being strong, a scenario of electroweak symmetry
breaking is discussed, and the gauginos are generally predicted to be heavier
than the sfermions.


title: On azimuthal spin correlations in Higgs plus jet events at LHC

abstract:
  We consider the recent proposal that the distribution of the difference
between azimuthal angles of the two accompanying jets in gluon-fusion induced
Higgs-plus-two-jet events at LHC reflects the CP of the Higgs boson produced.
We point out that the hierarchy between the Higgs boson mass and the jet
transverse energy makes this observable vulnerable to logarithmically enhanced
higher-order perturbative corrections. We present an evolution equation that
describes the scale variation of the azimuthal angular correlation for the two
jets. The emission of extra partons leads to a significant suppression of the
correlation. Using the HERWIG Monte Carlo event generator, we carry out a
parton-shower analysis to confirm the findings.


title:
QCD event generators with next-to-leading order matrix-elements and
  parton showers

abstract:
  A new method to construct event-generators based on next-to-leading order QCD
matrix-elements and leading-logarithmic parton showers is proposed. Matrix
elements of loop diagram as well as those of a tree level can be generated
using an automatic system. A soft/collinear singularity is treated using a
leading-log subtraction method. Higher order re-summation of the soft/collinear
correction by the parton shower method is combined with the NLO matrix-element
without any double-counting in this method.
  An example of the event generator for Drell-Yan process is given for
demonstrating a validity of this method.


title: Domains in the Nonperturbative QCD Vacuum

abstract:
  QCD vacuum gluon fields are modelled by hyperspherical domains of constant
field strength. The pure glue theory confines static quarks. Solutions of the
Dirac operator have chirality properties in agreement with lattice results.


title: Baryon Structure

abstract:
  A review of the theoretical activity in Italy in the research field of
Hadronic Physics is given. Specific focus is put on phenomenological models
based on the effective degrees of freedom of constituent quarks, on parton
distributions in hard processes in the Bjorken limit and on the possibility of
linking the two concepts via evolution equations. A brief introduction is given
also about the socalled generalized parton distributions.


title: Non-minimally Coupled Tachyon and Inflation

abstract:
  In this paper, we consider a model of tachyon with a non-minimal coupling to
gravity and study its cosmological effects. Regarding inflation we will show
that for a specific coupling of tachyon to gravity this model satisfies
observations and solves various problems which exist in the single and multi
tachyon inflation models.


title: B_s -> mu^+ mu^- and B -> X_s mu^+ mu^- in MSSM

abstract:
  Pure leptonic and semileptonic rare B decays, $B_s \to \mu^+ \mu^-$ and $B
\to X_s \mu^+ \mu^-$ in the minimal supersymmetric Standard Model (MSSM), in
particular, gluino and neutralino contributions to the decays, are discussed
under Br($B \to X_s \gamma$) and other experimental constraints . The general
scalar quark mass matrices as the new sources of flavor violation are
considered. We present Wilson coefficients of $bs$ transitions from $\gamma$,
$Z$, and neutral Higgs boson penguin diagrams by using vertex mixing method to
deal with scalar down-type quark flavor changing and also give their
expressions in MIA to show different sources of enhancements. We find that
under the experimental constraints, with large mixing of left-handed and
right-handed sbottom, $C^{(\prime)}_{10}$ can be enhanced by 10% compared with
SM, in two cases, heavy gluino and fine-tuning between
$\delta^{dLL}_{23}$($\delta^{dRR}_{23}$) and
$\delta^{dLR}_{23}$($\delta^{dRL}_{23}$) terms in $C^{(\prime)}_7$.
Particularly, $C_{10}$ and $C_{10}^{\prime}$ can reach a 20% enhancement in
some regions of parameters under experimental constraints. When CP-odd Higgs
$A^0$ is not too heavy ($\sim 250$GeV), and $\tan\beta$ is large ($\sim 40$),
neutral Higgs boson penguins with gluino and down-type squark in the loop can
significantly contribute to the $bs$ transition and the contributions can
compete with those due to the chargino and up-type squark loop.


title:
Proceedings to the Workshops ''What comes beyond the Standard model''
  2000,2001, VOLUME 1: Festschrift dedicated to the 60th birthday of Holger
  Bech Nielsen

abstract:
  The present volume is the collection of contributions by friends of Holger
Bech Nielsen for his 60th birthday.
  Contents:
  1.Unified internal space of spins and charges (N. Mankoc Borstnik)
2.Semitopological Q-Rings (M. Axenides) 3.Non-local axial anomalies in the
Standard model (D. Melikhov, B. Stech) 4.Could there be a fourth generation?
(C.D. Froggatt) 5.Another complex Bateman equation (D.B. Fairlie)
6.Non-associative loops for Holger Bech Nielsen (P.H. Frampton) 7.Particles,
fluids and vortices (J.W. van Holten) 8.Results on 2D current algebras (J.L.
Petersen) 9.Phase transition in gauge theories and the Planck scale physics
(L.V. Laperashvili and D.A. Ryzhikh) 10.Some remarks on the 'classical' large N
limit (P. Olesen) 11.String theory and the size of hadrons (L. Susskind)
12.Relativity and $c/sqrt3$ (S.I. Blinnikov, L.B. Okun and M.I. Vysotsky)
13.Vortices (Jeff Greensite)


title:
Evidence for Majorana Neutrinos: Dawn of a new era in spacetime
  structure

abstract:
  We show that Majorana particles belong to the Wigner class of fermions in
which the charge conjugation and the parity operators commute, rather than
anticommute. Rigorously speaking, Majorana spinors do not satisfy the Dirac
equation [a result originally due to M. Kirchbach, which we re-render here].
Instead, they satisfy a different wave equation, which we derive. This allows
us to reconcile St\"uckelberg-Feynman interpretation with the Majorana
construct. We present several new properties of neutral particle spinors and
argue that discovery of Majorana particles constitutes dawn of a new era in
spacetime structure.


title: Sources of sub-GZK cosmic rays

abstract:
  We analyze the existing evidence that BL Lacertae objects (BL Lacs) are
sources of the highest-energy cosmic rays. We argue that three independent
signatures observed in the real data -- (1) improvement of correlations with
corrections of trajectories for the Galactic magnetic field; (2) connection
between gamma-ray and UHECR emissions; (3) non-uniform distribution of
correlating rays over the sky -- are consistent with the hypothesis that a
substantial fraction of cosmic rays in the energy range 40-60 EeV are protons
accelerated in BL Lacs.


title: Double Charm Physics

abstract:
  We review the weak-decay and spectroscopy properties of baryons with two
charmed quarks. We also present the convergent speculations on exotic mesons
$(QQ\bar{q}\bar{q})$ with two heavy quarks and two light antiquarks.


title:
The radiative return at phi- and B-factories: small-angle photon
  emission at next to leading order

abstract:
  The radiative return offers the unique possibility for a measurement of the
cross section of electron--positron annihilation into hadrons over a wide range
of energies. The large luminosity of present phi- and B-factories easily
compensates for the additional factor of alpha due to the emission of a hard
photon. Final states with photons at large angles can be easily identified. The
rate for events with collinear photons, however, is enhanced by a large
logarithm and allows, in particular at lower energies, for a complementary
measurement.
  The Monte Carlo generator PHOKHARA, which includes next to leading order
corrections from virtual and real photon emission, has been extended from large
photon angles into the collinear region, using recent results for the virtual
corrections. In addition, the present version includes final state radiation
for muon and pion pair production and final states with four pions.
Implications for the experimental analysis at three typical energies, 1.02, 4
and 10.6 GeV, are presented: the magnitude of these new corrections is studied,
possibilities for the separation of initial and final state radiation are
proposed, and the differences with respect to the previous treatment based on
structure functions are investigated.


title: Supersymmetric Dark Matter - How Light Can the LSP Be?

abstract:
  Using a very minimal set of theoretical assumptions we derive a lower limit
on the LSP mass in the MSSM. We only require that the LSP be the lightest
neutralino, that it be responsible for the observed relic density and that the
MSSM spectrum respect the LEP2 limits. We explicitly do not require any further
knowledge about the MSSM spectrum or the mechanism of supersymmetry breaking.
Under these assumptions we determine a firm lower limit on the neutralino LSP
mass of $18\gev$. We estimate the effect of improved limits on the cold dark
matter relic density as well as the effects of improved LEP2-type limits from a
first stage of TESLA on the allowed range of neutralino LSP masses.


title:
A lower limit on the neutralino mass in the MSSM with non-universal
  gaugino masses

abstract:
  We discuss constraints on SUSY models with non-unified gaugino masses. We
concentrate on the slepton/gaugino sector and obtain a lower limit on the
neutralino mass combining direct limits, indirect limits as well as relic
density measurements.


title: Collider Tests of the Little Higgs Model

abstract:
  The little Higgs model provides an alternative to traditional candidates for
new physics at the TeV scale. The new heavy gauge bosons predicted by this
model should be observable at the Large Hadron Collider (LHC). We discuss how
the LHC experiments could test the little Higgs model by studying the
production and decay of these particles.


title:
Refinements in electroweak contributions to the muon anomalous magnetic
  moment

abstract:
  Effects of strong interactions on the two loop electroweak radiative
corrections to the muon anomalous magnetic moment, $a_\mu=(g_\mu-2)/2$, are
examined. Short-distance logs are shown to be unaffected. Computation of
long-distance contributions is improved by use of an effective field theory
approach that preserves the chiral properties of QCD and accounts for
constraints from the operator product expansion. Small, previously neglected,
two loop contributions, suppressed by a $1-4\sin^2\theta_W$ factor, are
computed and the complete three loop leading short-distance logs are
reevaluated. These refinements lead to a reduction in uncertainties and a
slight shift in the total electroweak contribution to $a_\mu^{\rm EW} =
154(1)(2)\times 10^{-11}$ where the first error corresponds to hadronic
uncertainties and the second is primarily due to the allowed Higgs mass range.


title: Determination of m_s and |V_us| from hadronic tau decays

abstract:
  The mass of the strange quark is determined from SU(3)-breaking effects in
the tau hadronic width. Compared to previous analyses, the contributions from
scalar and pseudoscalar spectral functions, which suffer from large
perturbative corrections, are replaced by phenomenological parametrisations.
This leads to a sizeable reduction of the uncertainties in the strange mass
from tau decays. Nevertheless, the resulting m_s value is still rather
sensitive to the moment of the invariant mass distribution which is used for
the determination, as well as the size of the quark-mixing matrix element
|V_us|. Imposing the unitarity fit for the CKM matrix, we obtain m_s(2
GeV)=117+-17 MeV, whereas for the present Particle Data Group average for
|V_us|, we find m_s(2 GeV)=103+-17 MeV. On the other hand, using an average of
m_s from other sources as an input, we are able to calculate the quark-mixing
matrix element |V_us|, and we demonstrate that if the present measurement of
the hadronic decay of the tau into strange particles is improved by a factor of
two, the determination of |V_us| is more precise than the current world
average.


title:
Perturbative and nonperturbative renormalization of anomalous quark
  triangles

abstract:
  Anomalous quark triangles with one axial and two vector currents are studied
in special kinematics when one of the vector currents carries a soft momentum.
According to the Adler-Bardeen theorem the anomalous longitudinal part of the
triangle is not renormalized in the chiral limit. We derive a new
nonrenormalization theorem for the transversal part of the triangle. This
nonrenormalization, in difference with the longitudinal part, holds on only
perturbatively. At the nonperturbative level we use the operator product
expansion and the pion dominance in the longitudinal part to determine the
magnetic susceptibility of the quark condensate, $\chi=-N_c/(4\pi^2 F_\pi^2)$.


title: Interactions of ultrahigh-energy neutrinos

abstract:
  Future detection of ultrahigh-energy neutrinos will open a new window on
physics at center-of-mass energy 10^5 GeV and higher. In particular,
observations of neutrino-initiated showers will help test the Standard Model
predictions for the neutrino-nucleon cross section.


title: The SU(2) Hidden Substructure of Quarks and the Kobaiashi-Maskawa Matrix

abstract:
  It is proposed that each quark is composed of two prequarks, called primons.
This composition generates a new hypercharge and a new kind of color called
supercolor. Such quark composition explains the Kobaiashi-Maskawa matrix
elements in terms of selection rules based on the new hypercharge. Also it is
shown that the doublet of quarks top/bottom is quite similar to the doublet
charm/strange. Besides, it is also shown that there should exist three Higgs
bosons involved in the generation of quark masses.


title:
Analytic models and forward scattering from accelerator to cosmic-ray
  energies

abstract:
  Analytic models for hadron-hadron scattering are characterized by analytical
parametrizations for the forward amplitudes and the use of dispersion relation
techniques to study the total cross section $\sigma_{tot}$ and the $\rho$
parameter. In this paper we investigate four aspects related to the application
of the model to $pp$ and $\bar{p}p$ scattering, from accelerator to cosmic-ray
energies: 1) the effect of different estimations for $\sigma_{tot}$ from
cosmic-ray experiments; 2) the differences between individual and global
(simultaneous) fits to $\sigma_{tot}$ and $\rho$; 3) the role of the
subtraction constant in the dispersion relations; 4) the effect of distinct
asymptotic inputs from different analytic models. This is done by using as a
framework the single Pomeron and the maximal Odderon parametrizations for the
total cross section. Our main conclusions are the following: 1) Despite the
small influence from different cosmic-ray estimations, the results allow us to
extract an upper bound for the soft pomeron intercept: $1 + \epsilon = 1.094$;
2) although global fits present good statistical results, in general, this
procedure constrains the rise of $\sigma_{tot}$; 3) the subtraction constant as
a free parameter affects the fit results at both low and high energies; 4)
independently of the cosmic-ray information used and the subtraction constant,
global fits with the odderon parametrization predict that, above $\sqrt s
\approx 70$ GeV, $\rho_{pp}(s)$ becomes greater than $\rho_{\bar{p}p}(s)$, and
this result is in complete agreement with all the data presently available. In
particular, we infer $\rho_{pp} = 0.134 \pm 0.005$ at $\sqrt s = 200$ GeV and
$0.151 \pm 0.007$ at 500 GeV (BNL RHIC energies).


title: Extracting vector mesons magnetic dipole moment from radiative decays

abstract:
  The possibility that the magnetic dipole moment (MDM) of light charged vector
mesons could be measured from radiative processes involving the production
(\tau \to \rho \nu \gamma) and decay(\rho \to \pi \pi \gamma) of vector mesons
is studied in a model independent way, via the soft-photon approximation. The
angular and energy distribution of photons emitted at small angles respect to
the final charged particle is found be sensitive to the effects of the MDM. We
also show that model dependent contributions have a general structure, by gauge
invariance requirements, that allows suppress them in the same kinematical
region where the MDM effect is more important in the model independent
approach.


title: Bounds on charged higgs boson in the 2HDM type III from Tevatron

abstract:
  We consider the Two Higgs Doublet Model (2HDM) of type III which leads to
Flavour Changing Neutral Currents (FCNC) at tree level. In the framework of
this model we can use an appropriate form of the Yukawa Lagrangian that makes
the type II model limit of the general type III couplings apparent. This way is
useful in order to compare with the experimental data which is model dependent.
The analytical expressions of the partial width $\Gamma (t \to H^+ b) $ are
derived and we compare with the data available at this energy range. We examine
the limits on the new parameters $\lambda_{ij}$ from the validness of
perturbation theory.


title: Phenomenological analysis of the Two Higgs Doublet Model

abstract:
  The Two Higgs Doublet model and its phenomenological implications are
discussed. A brief survey on the present status of this model is given. In
particular, we concentrate on the Two Higgs Doublet Model with Flavor Changing
Neutral Currents. First, we develop some new parametrizations of the 2HDM type
III, in such a way that the relation of it with models type I and type II
become apparent. Based on this parametrization we get some bounds on the mixing
vertex involving the second and third lepton generations, and lower bounds on
the mass of the pseudoscalar Higgs boson. Further, by using a parametrization
in which one of the vacuum expectation values vanishes, we constrain some
lepton flavor violating vertices, based on the $g-2 $muon factor and some
lepton flavor violating decays. Moreover, upper limits on the decay widths of
$\tau \to e\gamma, $and $\tau \to eee $are calculated, finding them to stay far
from the reach of near future experiments. On the other hand, as an addendum to
this work, we study the production and decays of top squarks at the Tevatron
collider in models of low-energy supersymmetry breaking. We consider that the
lightest Standard Model superpartner is a light neutralino that predominantly
decays into a photon and a light gravitino, and that the lighter stop is the
next-to-lightest Standard Model superpartner. For a modest projection of the
final Tevatron luminosity, $L\simeq 4$ fb$^{-1}$, stop masses of order 300 GeV
are accessible. We also consider the production and decay of ten degenerate
squarks, and we find that common squark masses up to 360 GeV are easily
accessible, and that the reach increases further if the gluino is light.


title:
Generalized parton distributions and double distributions for q q-bar
  pions

abstract:
  We consider two simple covariant models for pions (one with scalar and the
other with spin-1/2 constituents). Pion generalized parton distributions are
derived by integration over the light-cone energy. The model distributions are
consistent with all known properties of generalized parton distributions,
including positivity. We also construct the corresponding double distributions
by appealing to Lorentz invariance. These ostensibly constructed double
distributions lead to different generalized parton distributions that need not
respect the positivity constraints. This inconsistency arises from the
ambiguity inherent in defining double distributions in a one-component
formalism (even in the absence of the Polyakov-Weiss term). We demonstrate that
the correct model double distributions can be calculated from non-diagonal
matrix elements of twist-two operators.


title: Prediction of |V_{13}| and the Dirac phase in the Neutrino Mixing Matrix

abstract:
  We considered a model where |V_{13}|=0 so that delta=0 at M_R and analyzed
mixing angles and CP violation angles at the low energy scale by using the
renormalization group in the MSSM model. In this model, parameters at M_R scale
are two mixing angles (theta_{12} and theta_{23}), three neutrino masses, and
two Majorana phases. We found that (1) sin^2 2 theta_{12} at the low energy
scale must be less than that at $M_R$ scale, (2) the induced |V_{13}| can be as
large as 0.05 if masses of neutrinos are around 0.05 eV.


title:
Double Beta Decay Constraints on Neutrino Masses and Mixing; Reanalysis
  with KamLAND Data

abstract:
  In the light of KamLAND data just released, we reanalyze and update the
constraints on neutrino masses and mixing parameters, the most general ones
that can be derived in three-flavor mixing scheme of neutrinos with use of the
bounds imposed by neutrinoless double beta decay search and reactor
experiments. We point out that with KamLAND data and assuming Majorana
neutrinos one can derive, for the first time, an upper bound on neutrino
contribution to the cosmological \Omega parameter, \Omega_{\nu} \leq 0.070
h^{-2}, by using the current upper bound on mass parameters obtained by
Heidelberg-Moscow group, < m >_{\beta \beta} < 0.35 eV (90 % CL). If the bound
is tighten to < m >_{\beta \beta} < 0.1 eV by future experiments, it would lead
to a far severer bound \Omega_{\nu} \lsim 0.01 h^{-2}.


title:
Do parity doublets in the baryon spectrum reflect restoration of chiral
  symmetry?

abstract:
  We discuss the mass spectrum of highly-excited nucleon and $\Delta^*$
resonances. The spectrum exhibits parity doublets, pairs of resonances of
identical total angular momentum J but of opposite parity. It has been proposed
that the parity doublets evidence restoration of chiral symmetry at large
baryon excitation energies. We compare this conjecture with the possibility
that high-mass states are organized into $(L,S)$-multiplets with defined
intrinsic quark spins and orbital angular momenta. Indeed, the latter
interpretation results in a better description of the data. There is however a
small and statisticially not very significant trend of the data which might
indicate that chiral symmetry is not yet restored but does influence the masses
of highly excited states.


title: Neutrino Mass Matrix Out of Up-Quark Masses Only

abstract:
  Under the assumption of symmetric four zero texture for fermion mass matrices
in SO(10) model, the neutrino Dirc mass matrix is derived from the up-quark
mass matrix. By adjusting two scales of the Majorana mass sector, we can derive
observed neutrino two large mixing angles very naturally. It is indeed
remarkable that all the masses and mixings of neutrinos are expressed in terms
of only three known parameters, $m_t,m_c,m_u$. A typical example of our model
is \tan^2 2\theta_{\tau \mu}=\frac{4}{(1-2\frac{m_c}{\sqrt{m_u m_t}})^2}.


title: Some aspects of Dalitz decay pi0 -> e+ e- gamma

abstract:
  A calculation of the Dalitz decay in next-to-leading order in chiral
perturbation theory of two flavour case extended by virtual photons is
presented. The whole kinematic sector is covered and realistic experimental
situation is discussed.


title:
Soft SUSY breaking masses in a unified model with doublet-triplet
  splitting

abstract:
  We study soft supersymmetry breaking parameters in a supersymmetric unified
model which potentially solves the doublet-triplet splitting problem. In the
model the doublet-triplet splitting is solved by the discrete symmetry which is
allowed to be introduced due to the direct product structure of the gauge
group. The messenger fields for the gauge mediated supersymmetry breaking are
naturally embedded in the model. The discrete symmetry required by the
doublet-triplet splitting makes the gaugino masses non-universal and also
induces a different mass spectrum for the scalar masses from the ordinary
minimal gauge mediation model. Independent physical CP phases can remain in the
gaugino sector even after the R-transformation.


title:
Natural R-Parity, \mu-term, and Fermion Mass Hierarchy From Discrete
  Gauge Symmetries

abstract:
  In the minimal supersymmetric Standard Model with seesaw neutrino masses we
show how R-parity can emerge naturally as a discrete gauge symmetry. The same
discrete symmetry explains the smallness of the \mu-term (the Higgsino mass
parameter) via the Giudice--Masiero mechanism. The discrete gauge anomalies are
cancelled by a discrete version of the Green--Schwarz mechanism. The simplest
symmetry group is found to be Z_4 with a charge assignment that is compatible
with grand unification. Several other Z_N gauge symmetries are found for
N=10,12,18,36 etc, with some models employing discrete anomaly cancellation at
higher Kac-Moody levels. Allowing for a flavor structure in Z_N, we show that
the same gauge symmetry can also explain the observed hierarchy in the fermion
masses and mixings.


title:
D Meson Production in Neutrino DIS and Polarized Strange Quark
  Distribution

abstract:
  Semi-inclusive $D / \Dbar$ meson productions in neutrino deep inelastic
scattering are studied including ${\cal O}(\alpha_s)$ corrections. Supposing a
future neutrino factory, cross sections and spin asymmetries in polarized
processes are calculated by using various parametrization models of polarized
parton distribution functions. We suggest that $\Dbar$ production is promising
to directly extract the strange quark distribution.


title: A high energy determination of Yukawa couplings in SUSY models

abstract:
  We consider the production, at future lepton colliders, of final fermion,
sfermion, scalar pairs in SUSY models. For third family fermions and sfermions
and for charged Higgses, the leading Yukawa effect at one loop for large c.m.
energies comes from a linear logarithm of Sudakov type, that only depends, in
the MSSM, on one SUSY mass scale and on tan(beta). Assuming a relatively light
SUSY scenario, we illustrate a possible determination of tan(beta) at c.m.
energies of about 1 TeV, working systematically at subleading logarithmic
accuracy, at the one-loop level.


title: Parton interactions in the Bjorken aymptotics

abstract:
  We demonstrate the effective action scheme for the leading parton
interactions and discuss the symmetry properties. The interaction kernels are
particular cases of conformal symmetric two-particle kernels. There is a direct
relation to the conformal symmetric rational solution of the Yang-Baxter
equation.


title:
Intrinsic parton transverse momentum in next-to-leading-order pion
  production

abstract:
  We study pion production in proton-proton collisions within a pQCD-improved
parton model in next-to-leading order augmented by intrinsic transverse
momentum ($k_\perp$) of the partons. We find the introduction of $k_\perp$
necessary to reproduce the experimental data in the CERN SPS to RHIC energy
range. We study the influence of intrinsic $k_\perp$ on the so-called $K$
factor, the ratio of the NLO cross section to the Born term. A strong $p_T$
dependence is seen, especially in the 3-6 GeV transverse momentum region of the
outgoing pion, where nuclear effects (e.g. the Cronin effect) play an important
role.


title: Unbiased analysis of CLEO data at NLO and pion distribution amplitude

abstract:
  We discuss different QCD approaches to calculate the form factor
F^{\gamma^*\gamma\pi}(Q^2) of the \gamma^*\gamma\to\pi^{0} transition giving
preference to the light-cone QCD sum rules (LCSR) approach as being the most
adequate. In this context we revise the previous analysis of the CLEO
experimental data on F^{\gamma^*\gamma\pi}(Q^{2}) by Schmedding and Yakovlev.
Special attention is paid to the sensitivity of the results to the (strong
radiative) \alpha_s-corrections and to the value of the twist-four coupling
\delta^2. We present a full analysis of the CLEO data at the NLO level of
LCSRs, focusing particular attention to the extraction of the relevant
parameters to determine the pion distribution amplitude, i.e., the Gegenbauer
coefficients a_2 and a_4. Our analysis confirms our previous results and also
the main findings of Schmedding and Yakovlev: both the asymptotic, as well as
the Chernyak--Zhitnitsky pion distribution amplitudes are completely excluded
by the CLEO data. A novelty of our approach is to use the CLEO data as a means
of determining the value of the QCD vacuum non-locality parameter \lambda^2_q =
<\bar{q}D^2q>/<\bar{q}q> =0.4 GeV^2, which specifies the average virtuality of
the vacuum quarks.


title: QCD Effective Actions at High Temperature and the Quasiparticle Picture

abstract:
  Transport theory is an efficient approach to derive an effective theory for
the soft modes of QCD at high temperature. It is known that the leading order
operators of this theory can be obtained from (semi-classical) kinetic
equations of quasiparticles carrying classical or quantum color charges. Higher
order operators can also be obtained. Discrepancy between these quasiparticle
models starts for dimension 4 operators, which converge in the limit of high
dimensional color representations. These quasiparticle models are reviewed and
compared.


title: Instanton model of light hadrons: from low to high energies

abstract:
  Instanton liquid model being effective model of the QCD vacuum describes well
the hadrons at low as well at intermediate energies. Thus, contact with
perturbative QCD results is possible providing the unique information about the
quark-gluon distribution functions in the QCD vacuum and hadrons at low energy
normalization point. As an illustrative example we consider the pion transition
form factor for the process $\gamma ^*\gamma^*\to \pi^0$ at space-like values
of photon momenta. The leading and next-to-leading order power asymptotics of
the form factor and the relation between the light-cone pion distribution
amplitudes of twists 2 and 4 and the dynamically generated quark mass are
found.


title: From 3 nucleons to 3 quarks

abstract:
  Some short history of few-body methods originated from the famous
Skornyakov-Ter-Martirosyan equation is given, including latest development of
Faddeev formalism and Efimov states. The 3q system is shown to require an
alternative, which is provided by the hyperspherical method (K-harmonics) which
is highly successful for baryons.


title:
Neutrino mass, proton decay and dark matter in TeV scale universal extra
  dimension models

abstract:
  We show how the problem of small neutrino masses and suppressed proton decay
can be simultaneously resolved in 6-D universal extra dimension models (UED)
with a low fundamental scale using extended gauge groups that contain the local
$B-L$ symmetry. The extra space dimensions are compactified either on a
$T^2/Z_2$ or $T^2/Z_2\times Z'_2$ orbifold depending on whether the full gauge
group is $SU(2)_L\times U(1)_{I_{3R}}\times U(1)_{B-L}$ or $SU(2)_L\times
SU(2)_{R}\times U(1)_{B-L}$. In both cases, neutrino masses are suppressed by
an appropriate orbifold parity assignment for the standard model singlet
neutrinos and the proton decay rate is suppressed due to a residual discrete
symmetry left over from compactification. For lower values of the fundamental
scale, a dominant decay mode of the neutron is $n\to 3 \nu$. An interesting
consequence of the model is a possible two component picture for dark matter of
the universe.


title: Enhanced nonperturbative effects in jet distributions

abstract:
  We consider the triple differential distribution
d\Gamma/(dE_J)(dm_J^2)(d\Omega_J) for two-jet events at center of mass energy
M, smeared over the endpoint region m_J^2 << M^2, |2 E_J -M| ~ \Delta, \lqcd <<
\Delta << M. The leading nonperturbative correction, suppressed by
\lqcd/\Delta, is given by the matrix element of a single operator. A similar
analysis is performed for three jet events, and the generalization to any
number of jets is discussed. At order \lqcd/\Delta, non-perturbative effects in
four or more jet events are completely determined in terms of two matrix
elements which can be measured in two and three jet events.


title: Eta, eta-prime photoproduction and electroproduction off nucleons

abstract:
  The photo- and electroproduction of eta, eta-prime mesons on nucleons are
investigated within a relativistic chiral unitary approach based on coupled
channels. The s-wave potentials for electroproduction and meson-baryon
scattering are derived from a chiral effective Lagrangian which includes the
eta-prime as an explicit degree of freedom and incorporates important features
of the underlying QCD Lagrangian such as the axial U(1) anomaly. The effective
potentials are iterated in a Bethe-Salpeter equation and cross sections for
eta, eta-prime photo- and electroproduction from nucleons are obtained. The
results for the eta-prime photoproduction cross section on protons reproduce
the appearance of an S_{11} resonance around 1.9 GeV observed at ELSA. The
inclusion of electromagnetic form factors increases the predicted eta
electroproduction cross sections on the proton, providing a qualitative
explanation for the hard form factor of the photocoupling amplitude observed at
CLAS.


title: Nonperturbative QCD treatment of $J/\psi$ photoproduction

abstract:
  We present a nonperturbative QCD calculation of elastic $J/\psi$ meson
production in photon-proton scattering at high energies. Using light cone wave
functions of the photon and vector mesons, and the framework of the model of
the stochastic QCD vacuum, we calculate the differential and integrated elastic
cross sections for $\gamma p \goto J/\psi p $ . With an energy dependence
following the two-pomeron model we are able to give a consistent description of
the integrated cross sections and the differential cross sections at low $|t|$
in the range from 20 GeV up to the highest HERA energies. We discuss different
approaches to introduce saturation and find no specific effects up to energies
presently available. We also calculate and compare to experiments the cross
section for $\upsilon$ photoproduction.


title: Quark and Lepton Masses and Mixing Angles from Superstring Constructions

abstract:
  We show that the observed structure of quark and lepton masses and mixing
angles can arise entirely geometrically from superstring constructions, at the
renormalizable level. The model we consider is a $Z_3$ orbifold
compactification of heterotic string with two Wilson lines, where three
families of particles of $SU(3)_c\times SU(2)_L\times U(1)_Y$, including
Higgses, are automatically present. In orbifold models, Yukawa couplings can be
calculated explicitly, and it is known that they get exponential supression
factors depending on the distance between the fixed points to which the fields
are attached. We find that in the $Z_3$ case, the quark and charged-lepton mass
hierarchies can easily be obtained for reasonable values of the three moduli
determining the radii of the compactified space, $T_i\sim 1$. For the
neutrinos, due to the smallness of their Dirac masses, the required scale for
the see-saw mechanism to give the correct masses is found to be within reach of
the electroweak scale. Finally, we find that one of the small number of
possibilities for quark and lepton mass matrices yields consistent results for
the mixing angles and the weak CP violation phase. Although our scheme relies
on the mixing between fields due to Fayet-Iliopoulos breaking, it is
considerably more predictive than alternative models of flavour.


title: Reduction of one-loop tensor 5-point integrals

abstract:
  A new method for the reduction of one-loop tensor 5-point integrals to
related 4-point integrals is proposed. In contrast to the usual
Passarino-Veltman reduction and other methods used in the literature, this
reduction avoids the occurrence of inverse Gram determinants, which potentially
cause severe numerical instabilities in practical calculations. Explicit
results for the 5-point tensor coefficients are presented up to rank 4. The
expressions for the reduction of the relevant 1-, 2-, 3-, and 4-point tensor
coefficients to scalar integrals are also included; apart from these standard
integrals no other integrals are needed.


title: Polarized Hyperons from pA Scattering in the Gluon Saturation Regime

abstract:
  We study the production of transversely polarized Lambda hyperons in
high-energy collisions of protons with large nuclei. The large gluon density of
the target at saturation provides an intrinsic semi-hard scale which should
naturally allow for a weak-coupling QCD description of the process in terms of
a convolution of the quark distribution of the proton with the elementary
quark-nucleus scattering cross section (resummed to all twists) and a
fragmentation function. In this case of transversely polarized Lambda
production we employ a so-called polarizing fragmentation function, which is an
odd function of the transverse momentum of the Lambda relative to the
fragmenting quark. Due to this k_t-odd nature, the resulting Lambda
polarization is essentially proportional to the derivative of the quark-nucleus
cross section with respect to transverse momentum, which peaks near the
saturation momentum scale. Such processes might therefore provide generic
signatures for high parton density effects and for the approach to the
``black-body'' (unitarity) limit of hadronic scattering.


title:
Full one-loop electroweak radiative corrections to single Higgs
  production in e+ e-

abstract:
  We present the full ${{\cal O}}(\alpha)$ electroweak radiative corrections to
single Higgs production in \epemt. This takes into account the full one-loop
corrections as well as the effects of hard photon radiation. We include both
the fusion and Higgs-strahlung processes. The computation is performed with the
help of {\tt GRACE-loop} where we have implemented a generalised non-linear
gauge fixing condition. The latter includes 5 gauge parameters that can be used
for checks on our results. Besides the UV, IR finiteness and gauge parameter
independence checks it proves also powerful to test our implementation of the
5-point function. We find that for a 500GeV machine and a light Higgs of mass
150GeV, the total ${{\cal O}}(\alpha)$ correction is small when the results are
expressed in terms of $\alpha_{{\rm QED}}$. The total correction decreases
slightly for higher energies. For moderate centre of mass energies the total
${{\cal O}}(\alpha)$ decreases as the Higgs mass increases, reaching -10% for
$M_H=350$GeV and $\sqrt{s}=500$GeV. In order to quantify the genuine weak
corrections we have subtracted the universal virtual and bremsstrahlung
correction from the full ${{\cal O}}(\alpha)$. We find, for $M_H=150$GeV, a
weak correction slowly decreasing from -2% to -4% as the energy increases from
$\sqrt{s}=300$GeV to $\sqrt{s}=1$TeV after expressing the tree-level results in
terms of $G_\mu$


title:
Interference of Conversion and Bremsstrahlung Amplitudes in the Decay
  K_L -> mu^+ mu^- gamma

abstract:
  In the region of large mu^+ mu^- invariant mass, the decay spectrum of K_L ->
mu^+ mu^- gamma deviates from the Dalitz pair spectrum, as a result of
interference between conversion (K_L -> gamma^* gamma -> mu^+ mu^- gamma) and
bremsstrahlung amplitudes. The latter is proportional to the K_L -> mu^+ mu^-
matrix element, whose 2 gamma-absorptive part appears to dominate the observed
K_L -> mu^+ mu^- decay rate. We examine the extent to which a scrutiny of the
K_L -> mu^+ mu^- gamma spectrum in the end-point region could provide evidence
on the real part of the K_L -> mu^+ mu^- amplitude. As a by-product, we obtain
the absorptive part of the K_L -> gamma^* gamma form factor, using data on the
K_L -> pi^+ pi^- gamma spectrum.


title:
Radiative corrections to neutrino mass matrix in the Standard Model and
  beyond

abstract:
  We study the effect of radiative corrections on the structure of neutrino
mass matrix. We analyze the renormalization of the matrix from the electroweak
scale $m_Z$ to the scale $m_0$ at which the effective operator that gives
masses to neutrinos is generated. Apart from Standard Model and MSSM,
non-standard extensions of SM are considered at a scale $m_X$ intermediate
between $m_Z$ and $m_0$. We find that the dominant structure of the neutrino
mass matrix does not change. SM and MSSM corrections produce small (few
percents) independent renormalization of each matrix element. Non-standard
(flavor changing) corrections can modify strongly small (sub-dominant) matrix
elements, which are important for the low energy phenomenology. In particular,
we show that all sub-dominant elements can have purely radiative origin, being
zero at $m_0$. The set of non-zero elements at $m_0$ can be formed by (i)
diagonal elements (unit matrix); (ii) $M_{ee}$ and $M_{\mu\tau}$; (iii)$M_{ee}$
and $\mu\tau$-block elements; (iv) $\mu\tau$-block elements. In the case of
unit matrix, both atmospheric and solar mixing angles and mass squared
differences are generated radiatively.


title: Baryon Number Violation and String Topologies

abstract:
  In supersymmetric scenarios with broken R-parity, baryon number violating
sparticle decays become possible. In order to search for such decays, a good
understanding of expected event properties is essential. We here develop a
complete framework that allows detailed studies. Special attention is given to
the hadronization phase, wherein the baryon number violating vertex is
associated with the appearance of a junction in the colour confinement field.
This allows us to tell where to look for the extra (anti)baryon directly
associated with the baryon number violating decay.


title: Post-inflationary thermalization with hadronization scenario

abstract:
  We study thermalization of the early Universe when the inflaton can decay
into the Standard Model (SM) quarks and gluons, using QCD arguments. We
describe the possible formation of the thermal plasma of soft gluons and quarks
well before the completion of reheating. Relevant interaction rates of leading
order processes and the corresponding thermalization time scale is presented.
We discuss hadronization while thermalizing the decay products of the inflaton,
when the reheat temperature of the Universe is below the QCD phase transition
but above the temperature of the Big Bang nucleosynthesis.


title: On the neutrino vector and axial vector charge radius

abstract:
  A Majorana neutrino is characterized by just one flavor diagonal
electromagnetic form factor: the anapole moment, that in the static limit
corresponds to the axial vector charge radius <r^2_A>. As is the case for the
vector charge radius of a Dirac neutrino, proving that this is a well defined
physical quantity is non trivial. I will first describe briefly the origin of
the long standing controversy about the physical or non physical nature of the
neutrino charge radius. Then I will argue that, in contrast to Dirac neutrino
electromagnetic form factors, for Majorana neutrinos cosmological and
astrophysical arguments do not provide useful informations on <r^2_A>, and
therefore this quantity has to be studied by means of terrestrial experiment.
Finally, I will discuss the constraints that can be derived on <r^2_A> for the
tau neutrino from a comprehensive analysis of the data on single photon
production off Z-resonance, and I will conclude with a few comments on
$\nu_\mu$ scattering data from the NuTeV, E734, CCFR and CHARM-II
collaborations and on the limits implied for <r^2_A> for the muon neutrino.


title:
Frame Dependence of the Pair Contribution to the Pion Electromagnetic
  Form Factor in a Light-Front Approach

abstract:
  The frame dependence of the pair-term contribution to the electromagnetic
form factor of the pion is studied within the Light Front approach. A symmetric
ansatz for the pion Bethe-Salpeter amplitude with a pseudo scalar coupling of
the constituent to the pion field is used.
  In this model, the pair term vanishes for the Drell-Yan condition, while it
is dominant for momentum transfer along the light-front direction.


title: Transport coefficients and quantum fields

abstract:
  Various aspects of transport coefficients in quantum field theory are
reviewed. We describe recent progress in the calculation of transport
coefficients in hot gauge theories using Kubo formulas, paying attention to the
fulfillment of Ward identities. We comment on why the color conductivity in hot
QCD is much simpler to compute than the electrical conductivity. The
nonperturbative extraction of transport coefficients from lattice QCD
calculations is briefly discussed.


title:
Limits on the brane fluctuations mass and on the brane tension scale
  from electron-positron colliders

abstract:
  In the context of the brane-world scenarios with compactified large extra
dimensions, we study the production of the possible massive brane oscillations
(branons) in electron-positron colliders. We compute their contribution to the
electroweak gauge bosons decay width and to the single-photon and single-Z
processes. With LEP-I results and assuming non observation at LEP-II, we
present exclusion plots for the brane tension $\tau = f^4$ and the branon mass
$M$. Prospects for the next generation of electron-positron colliders are also
considered.


title: LMA MSW solution of the solar neutrino problem and first KamLAND results

abstract:
  The first KamLAND results are in a very good agreement with the predictions
made on the basis of the solar neutrino data and the LMA realization of the MSW
mechanism. We perform a combined analysis of the KamLAND (rate, spectrum) and
the solar neutrino data with a free boron neutrino flux f_B. The best fit
values of neutrino parameters are Delta m^2 = 7.3e-5 eV^2, tg^2 theta = 0.41
and f_B = 1.05 with the 1 sigma intervals: Delta m^2 = (6.2 - 8.4)e-5 eV^2,
tg^2 theta = 0.33 - 0.54. We find the 3 sigma upper bounds: Delta m^2 < 2.8e-4
eV^2 and tg^2 theta < 0.84, and the lower bound Delta m^2 > 4e-5 eV^2. At 99%
C.L. the KamLAND spectral result splits the LMA region into two parts with the
preferred one at Delta m^2 < 1e-4 eV^2. The higher Delta m^2 region is accepted
at about 2 sigma level. We show that effects of non-zero 13-mixing, sin^2
theta_{13} < 0.04, are small leading to a slight improvement of the fit in
higher Delta m^2 region. In the best fit point we predict for SNO: CC/NC = 0.33
+0.05-0.03 and A_{DN}(SNO) = 2.8+-0.8 % (68% C.L.), and A_{DN}(SNO) < 9 % at
the 3 sigma level. Further improvements in the determination of the parameters
are discussed and implications of the solar neutrino and KamLAND results are
considered.


title: Heavy Quarkonium Inclusive Decays: Theoretical Status and Perspectives

abstract:
  I review some recent progress and open problems in the calculation of
heavy-quarkonium inclusive decay widths into light particles in the framework
of QCD non-relativistic effective field theories.


title: Electroweak Standard Model and Precision Tests

abstract:
  I give an introduction and overview of recent developments in high precision
tests of the Standard Model. This includes a summary of Z-pole measurements, a
brief account of the NuTeV result on neutrino-nucleon scattering, the anomalous
magnetic moment of the muon, and implications for the Higgs boson mass.


title:
Supersymmetric QCD corrections to lightest Higgs boson associated
  production with top quark pair at Linear Colliders

abstract:
  Supersymmetric (SUSY) QCD corrections to the lightest neutral Higgs boson
associated production with top quark pair are studied in the minimal
supersymmetric standard model (MSSM) at Linear colliders. Our calculations show
that the SUSY QCD effects generally are very moderate (say 10%) and under
control, except for some rescattering effects which lead to a breakdown of
perturbation theory and require a more detailed study. In the vicinity of the
production threshold for the favorable model parameters under the framework of
the on-shell renormalization scheme, SUSY QCD can be as large as about -50%.
Such effects might be acted as the probe to determine the sign of $M_{LR}\equiv
A_t-\mu/\tan\beta$.


title: Final-State Phases in $B \to D \pi, D^* \pi$, and $D \rho$ Decays

abstract:
  The final-state phases in $\bar{B} \to D \pi, D^* \pi$, and $D \rho$ decays
appear to follow a pattern similar to those in $D \to \bar{K} \pi$, $\bar{K}^*
\pi$, and $\bar{K} \rho$ decays. Each set of processes is characterized by
three charge states but only two independent amplitudes, so the amplitudes form
triangles in the complex plane. For the first two sets the triangles appear to
have non-zero area, while for the $D \rho$ or $\bar{K} \rho$ decays the areas
of the triangles are consistent with zero. Following an earlier discussion of
this behavior for $D$ decays, a similar analysis is performed for B decays, and
the relative phases and magnitudes of contributing amplitudes are determined.
The significance of recent results on $\ob \to D^{(*)0} \bar{K}^{(*)0}$ is
noted. Open theoretical and experimental questions are indicated.


title: Thermal Pions at Finite Isospin Chemical Potential

abstract:
  The density corrections, in terms of the isospin chemical potential $\mu_I$,
to the mass of the pions are studied in the framework of the SU(2) low energy
effective chiral lagrangian. The pion decay constant $f_{\pi}(T, \mu_{I})$ is
also analized. As a function of temperature for $\mu_I =0$, the mass remains
quite stable, starting to grow for very high values of $T$, confirming previous
results. However, there are interesting corrections to the mass when both
effects (temperature and chemical potential) are simultaneously present. At
zero temperature the $\pi ^{\pm}$ should condensate when $\mu_{I} = \mp
m_{\pi}$. This is not longer valid anymore at finite $T$. The mass of the
$\pi_0$ acquires also a non trivial dependence on $\mu_I$ due to the finite
temperature.


title: Confinement Phenomenology in the Bethe-Salpeter Equation

abstract:
  We consider the solution of the Bethe-Salpeter equation in Euclidean metric
for a qbar-q vector meson in the circumstance where the dressed quark
propagators have time-like complex conjugate mass poles. This approximates
features encountered in recent QCD modeling via the Dyson-Schwinger equations;
the absence of real mass poles simulates quark confinement. The analytic
continuation in the total momentum necessary to reach the mass shell for a
meson sufficiently heavier than 1 GeV leads to the quark poles being within the
integration domain for two variables in the standard approach. Through Feynman
integral techniques, we show how the analytic continuation can be implemented
in a way suitable for a practical numerical solution. We show that the would-be
qbar-q width to the meson generated from one quark pole is exactly cancelled by
the effect of the conjugate partner pole; the meson mass remains real and there
is no spurious qbar-q production threshold. The ladder kernel we employ is
consistent with one-loop perturbative QCD and has a two-parameter infrared
structure found to be successful in recent studies of the light SU(3) meson
sector.


title: B-->KK decays with the soft-gluon corrections

abstract:
  We analyze the B->KK decays with the soft-gluon corrections by using the QCD
light-cone sum rules (LCSR). Although QCD factorization approach calculates the
leading order factorization parts and the radiative corrections from hard-
gluon exchanges at $\alpha_{s}$ order, it is worthwhile to estimate the
nonfactorizable soft-gluon contributions from all the tree and penguin diagrams
systematically. Our results show that the soft-gluon effects always decrease
the branching ratios and give a few percentage corrections at most in the B->KK
decays.


title:
Multiplicity Fluctuation at Second-order Phase Transition in QGP on the
  Base of Squeezed States

abstract:
  We use the generalized squeezed state description in the framework of the
Ginzburg-Landau theory. Multiplicity distributions of the squeezed states are
studied at second-order phase transition at different squeeze factors. It is
shown that the normalized factorial moments exhibit a specific behaviour as
functions of the resolution scale. We obtain the values of the scaling exponent
which coincides with experimental data at small squeeze factor.


title: Brane-localized Kinetic Terms in the Randall-Sundrum Model

abstract:
  We examine the effects of boundary kinetic terms in the Randall-Sundrum model
with gauge fields in the bulk. We derive the resulting gauge Kaluza-Klein (KK)
state wavefunctions and their corresponding masses, as well as the KK gauge
field couplings to boundary fermions, and find that they are modified in the
presence of the boundary terms. In particular, for natural choices of the
parameters, these fermionic couplings can be substantially suppressed compared
to those in the conventional Randall-Sundrum scenario. This results in a
significant relaxation of the bound on the lightest gauge KK mass obtained from
precision electroweak data; we demonstrate that this bound can be as low as a
few hundred GeV. Due to the relationship between the lightest gauge KK state
and the electroweak scale in this model, this weakened constraint allows for
the electroweak scale to be near a TeV in this minimal extension of the
Randall-Sundrum model with bulk gauge fields, as opposed to the conventional
scenario.


title:
Charge asymmetry in K+- --> \pi+-\gamma\gamma induced by the
  electromagnetic penguin operators

abstract:
  The CP-violating charge asymmetry in decays K+- --> \pi+- \gamma\gamma, which
is induced by the electromagnetic penguin operators, has been studied both in
thestandard model and in its extensions. Because of a large enhancement of the
Wilson coefficients of the electromagnetic penguin operators in the
supersymmetric extensions of the standard model, a significant upper bound on
this charge asymmetry could be expected, and thus high precision measurements
of this interesting CP-violating quantity might explore new physics effects
beyond the standard model.


title:
Quark-Hadron Duality in Photoabsorption Sum Rules and Two Photon Decays
  of Meson Resonances

abstract:
  The idea of quark-hadron duality is developed and applied to integral sum
rules for the photoexcitation of meson resonances. Some applications of the
presented approach in the light and heavy quark sectors are made, and the role
of the scalar diquark cluster degrees of freedom in the radiative formation of
light scalar mesons is discussed.


title: Low Energy Pion Physics

abstract:
  In these notes we present an introductory review on various topics about low
energy pion physics (some kaon physics is discussed as well). Among these, we
include the uses of analyticity and unitarity to describe partial wave
amplitudes (for which we give accurate and economical parametrizations) and
form factors; (forward) dispersion relations; and the use of the
Froissart--Gribov representation to evaluate accurately the low energy
parameters (scattering lengths and effective ranges) for higher ($l\geq1$)
waves. Finally, we describe some pion physics in QCD and then pass on to study
the nonlinear sigma model, and the chiral perturbation theory approach to low
energy pion interactions.\hb \indent Most of the results presented here are
well known, but we also give a set of state of the art, precise determinations
of some scattering lengths as well as an independent calculation of three of
the parameters $\bar{l}_2$, $\bar{l}_4$, $\bar{l}_6$
  (to one loop), and one $\bar{f}_2$, to two loops, that appear in chiral
perturbation theory. The S waves are discussed and compared with chiral
perturbation theory expectations, and the same is done for larger $l$
scattering lengths and effective range parameters. Also new is the evaluation
of some electromagnetic corrections.


title: Quark number susceptibilities of hot QCD up to g^6ln(g)

abstract:
  The pressure of hot QCD has recently been determined to the last
perturbatively computable order g^6 ln(g) by Kajantie et al. using
three-dimensional effective theories. A similar method is applied here to the
pressure in the presence of small but non-vanishing quark chemical potentials,
and the result is used to derive the quark number susceptibilities in the limit
mu = 0. The diagonal quark number susceptibility of QCD with n_f flavours of
massless quarks is evaluated to order g^6ln(g) and compared with recent lattice
simulations. It is observed that the results qualitatively resemble the lattice
ones, and that when combined with the fully perturbative but yet undetermined
g^6 term they may well explain the behaviour of the lattice data for a wide
range of temperatures.


title: The Dipole Picture and Saturation in Soft Processes

abstract:
  We attempt to describe soft hadron interactions in the framework of
saturation models, one based upon the Balitsky-Kovchegov non-linear equation
and another one due to Golec-Biernat and W\"{u}sthoff. For $pp$, $Kp$, and $\pi
p$ scattering the relevant hadronic wave functions are formulated, and total,
elastic cross-sections, and the forward elastic slope are calculated and
compared to experimental data. The saturation mechanism leads to reasonable
reproduction of the data for the quantities analyzed, except for the forward
elastic slope, where the predicted increase with energy is too moderate.


title:
Influence of the beam-size or MD-effect on particle losses at
  B-factories PEP-II and KEKB

abstract:
  For the $e^+ e^- \to e^+ e^- \gamma$ process at colliding beams,
macroscopically large impact parameters give an essential contribution to the
standard cross section. These impact parameters may be much larger than the
transverse sizes of the colliding bunches. It means that the standard
calculations have to be essentially modify. In the present paper such a
beam-size or MD-effect is calculated for bremsstrahlung at B-factories PEP-II
and KEKB using the list of nominal parameters from Review of Particle Physics
(2002). We find out that this effect reduces beam losses due to bremsstrahlung
by about 20%.


title: Phenomenological Schwinger-Dyson approach to eta-eta' mass matrix

abstract:
  It is reviewed pedagogically how a very successful description of the
eta-eta' mass matrix can be achieved in the consistently coupled
Schwinger-Dyson and Bethe-Salpeter approach in spite of the limitations of the
ladder approximation. This description is in agreement with both phenomenology
and lattice results.


title: Hadron Production in Relativistic Nuclear Collisions

abstract:
  Relativistic nucleus-nucleus collisions create a "fireball" of strongly
interacting matter at high energy density. At very high energy this is
suggested to be partonic matter, but at lower energy it should consist of yet
unknown hadronic, perhaps coherent degrees of freedom. The freeze-out of this
high density state to a hadron gas can tell us about properties of fireball
matter.


title: Comment on "Vector and axial-vector mesons at finite temperature"

abstract:
  It is shown, that the correlators of vector and axial-vector currents at
finite temperature T in order T^2 reduce to mixing of vacuum VV and AA
correlators with universal mixing coefficient given by the parameter \epsilon =
T^2/6 F^2_{\pi}, unlike the claim in the recent paper by Mallik and Sarkar [1].


title: Electromagnetic cavities and Lorentz invariance violation

abstract:
  Within the model of a Lorentz violating extension of the Maxwell sector of
the standard model, modified light propagation leads to a change of the
resonance frequency of an electromagnetic cavity, allowing cavity tests of
Lorentz violation. However, the frequency is also affected by a
material-dependent length change of the cavity due to a modified Coulomb
potential arising from the same Lorentz violation as well. We derive the
frequency change of the cavity taking both into account. The new effects
derived are negligible for present experiments, but will be more pronounced in
future tests using novel resonator materials.


title: Schwinger-Dyson approach to light pseudoscalars

abstract:
  We review briefly some of the successes of Schwinger-Dyson (SD) approach to
the physics of quarks and hadrons, primarily light pseudoscalar mesons
including eta and eta'. The main purpose of this paper is to point out that SD
results on eta and eta' mesons can be formulated and given also in the
two-mixing-angle scheme.


title:
The nonleptonic decays Bc->Ds antiD0 and Bc->Ds D0 in a relativistic
  quark model

abstract:
  In the wake of exploring CP-violation in the decays of B and Bc mesons, we
perform the straightforward calculation of their nonleptonic decay rates within
a relativistic quark model. We confirm that the decays Bc->Ds antiD0 and Bc->Ds
D0 are well suited to extract the Cabibbo-Kobayashi-Maskawa angle \gamma
through the amplitude relations because their decay widths are the same order
of magnitude. In the b-c sector the decays B->D K and Bc->DD lead to squashed
triangles which are therefore not so useful to determine the angle
experimentally. We also determine the rates for other nonleptonic Bc-decays and
compare our results with the results of other studies.


title:
The photon-neutrino interaction in non-commutative gauge field theory
  and astrophysical bounds

abstract:
  In this letter we propose a possible mechanism of left- and right-handed
neutrino couplings to photons, which arises quite naturally in non-commutative
gauge field theory. We estimate the predicted additional energy-loss in stars
induced by space-time non-commutativity. The usual requirement that any new
energy-loss mechanism in globular stellar clusters should not excessively
exceed the standard neutrino losses implies a scale of non-commutative gauge
theory above the scale of weak interactions.


title: Neutron-antineutron Oscillations in the Trapping Box

abstract:
  We have reexamined the problem of $n-\bar n$ oscillations for ultra-cold
neutrons (UCN) confined within a trap. We have shown that the growth of the
$\bar n$ component with time is to a decent accuracy given by $P(\bar n)=
\epsilon^2_{n\bar n} t_Lt,$ where $\epsilon_{n\bar n}$ is the mixing parameter,
$t_L\sim 1 $ sec in the neutron propagation time between subsequent collisions
with the trap walls. Possible corrections to this law and open questions are
discussed.


title:
Rhad: A program for the evaluation of the hadronic R-ratio in the
  perturbative regime of QCD

abstract:
  This paper describes the fortran program rhad which performs a numerical
evaluation of the photon-induced hadronic R-ratio, R(s), related to the cross
section for electron-positron annihilation, for a given center-of-mass energy
\sqrt{s}. In rhad the state-of-the-art perturbative corrections to R(s) are
implemented and the running and decoupling of the strong coupling constant and
the quark masses is automatically treated consistently. Several options allow
for a flexible use of the program.


title:
Quenching of High pT Hadron Spectra by Hadronic Interactions in Heavy
  Ion Collisions at RHIC

abstract:
  Typically the materialization of high energetic transverse partons to
hadronic jets is assumed to occur outside the reaction zone in a relativistic
heavy ion collision. In contrast, a quantum mechanical estimate yields a time
on the order of only a few fm/c for building up the hadronic wavefunction for
jets with typical transverse momenta of pT < 10 GeV as accessible at RHIC
facilities. The role of possible elastic or inelastic collisions of these high
pT particles with the bulk of hadrons inside the fireball is addressed by means
of an opacity expansion in the number of collisions. This analysis shows that
the hadronic final state interactions can in principle account for the
modification of the (moderate) high pT spectrum observed for central collisions
at RHIC.


title: Impact Representation of Generalized Distribution Amplitudes

abstract:
  We develop an impact representation for the generalized distribution
amplitude which describes the exclusive hadronization of a quark-antiquark pair
to a pair of mesons. Experiments such as gamma^* gamma -> pi pi and gamma^* N
-> pi pi N' are shown to probe the transverse size of the hadronization region
of the quark antiquark pair that one can interpret as the transverse overlap of
the two emerging mesons. An astonishing feature of this description is that low
energy pi pi phase shift analysis can be used for understanding some properties
of quark hadronization process.


title: Uncertainties in the MSbar bottom quark mass from relativistic sum rules

abstract:
  A detailed compilation of uncertainties in the MSbar bottom quark mass
m_b(m_b) obtained from low-n spectral sum rules at order alpha_s^2 is given
including charm mass effects and secondary b production. The experimental
continuum region above 11.1 GeV is treated conservatively. An inconsistency of
the PDG averages for the electronic partial widths of Upsilon(4S) and
Upsilon(5S) is pointed out. From our analysis we obtain m_b(m_b)=4.20\pm 0.09
GeV. The impact of future CLEO data is discussed.


title: Spatial 't Hooft loop to cubic order in hot QCD

abstract:
  Spatial 't Hooft loops of strength k measure the qualitative change in the
behaviour of electric colour flux in confined and deconfined phase of SU (N)
gauge theory. They show an area law in the deconfined phase, known analytica
lly to two loop order with a ``k-scaling'' law k(N-k). In this paper we comput
e the O(g^3) correction to the tension. It is due to neutral gluon fields that
get their mass through interaction with the wall. The simple k-scaling is lost
in cubic order. The generic problem of non-convexity shows up in this order an
d the cure is provided. The result for large N is explicitely given. We show
tha t nonperturbative effects appear at O(g^5).


title: Towards Order alpha_s^4 Accuracy in tau-decays

abstract:
  Recently computed terms of orders O(\alpha_s^4 n_f^2) in the perturbative
series for the tau decay rate, and similar (new) strange quark mass
corrections, are used to discuss the validity of various optimization schemes.
The results are then employed to arrive at improved predictions for the
complete terms order O(\alpha_s^4) and O(\alpha_s^5) in the massless limit as
well as for terms due to the strange quark mass. Phenomenological implications
are presented.


title: Partial-wave analysis of two-hadron fragmentation functions

abstract:
  We reconsider the option of extracting the transversity distribution by using
interference fragmentation functions into two leading hadrons inside the same
current jet. To this end, we perform a new study of two-hadron fragmentation
functions. We derive new positivity bounds on them. We expand the hadron pair
system in relative partial waves, so that we can naturally incorporate in a
unified formalism specific cases already studied in the literature, such as the
fragmentation functions arising from the interference between the s- and p-wave
production of two mesons, as well as the production of a spin-one hadron. In
particular, our analysis clearly distinguishes two different ways to access the
transversity distribution in two-hadron semi-inclusive leptoproduction.


title: Singular Cross Sections in Muon Colliders

abstract:
  We address the problem that the cross section for the collisions of unstable
particles diverges, if calculated by standard methods. This problem is
considered for beams much smaller than the decay length of the unstable
particle, much larger than the decay length and finally also for pancake-
shaped beams. We find that in all cases this problem can be solved by taking
into account the production/propagation of the unstable particle and/or the
width of the incoming wave packets in momentum space.


title: Hadronic Entropy Enhancement and Low Density QGP

abstract:
  Recent studies show that for central collisions the rising of the incident
energy from AGS to RHIC decreases the value of the chemical potential in the
Hadron-QGP phase diagram. Thus, the formation of QGP at RHIC energies in
central collisions may be expected to occur at very small values of the
chemical potential. Using many different relativistic mean-field hadronic
models (RMF) at this regime we show that the critical temperature for the
Hadron-QGP transition is hadronic model independent. We have traced back the
reason for this and conclude that it comes from the fact that the QGP entropy
is much larger than the hadronic entropy obtained in all the RMF models. We
also find that almost all of these models present a strong entropy enhancement
in the hadronic sector coming from the baryonic phase transition to a
nucleon-antinucleon plasma. This result is in agreement with the recent data
obtained in the STAR collaboration at RHIC where it was found a rich
proton-antiproton matter.


title:
Five-loop vacuum polarization in pQCD: O(m_q^2\alpha_s^4 n_f^2)
  contribution

abstract:
  We present the analytical calculation of the contribution of order m_q^2
\alpha_s^4 n_f^2 to the absorptive part of the vacuum polarization function of
vector currents. This term constitutes an important gauge-invariant part of the
full O(m_q^2 alpha_s^4) correction to the total cross-section of e^+ e^-
annihilation into hadrons. The results are compared to predictions following
from various optimization schemes.


title: Present Status of Inclusive Rare B Decays

abstract:
  We give a status report on inclusive rare B decays, highlighting recent
developments and open problems. We focus on the decay modes $B \to X_{s,d}
\gamma$, $ B \to X_s \ell^+\ell^-$ and $B \to X_s \nu \bar \nu$ and on their
role in the search for new physics. Most of the inclusive rare B decays are
important modes of flavour physics due to the small hadronic uncertainties.
They can be regarded as laboratories to search for new physics. We collect the
experimental data already available from CLEO and the $B$ factories BABAR and
BELLE. We review the NLL and NNLL QCD calculations of the inclusive decay rates
that were recently completed, and discuss future prospects, especially the
issue of the charm mass scheme ambiguity. Finally, we analyse the
phenomenological impact of these decay modes, in particular on the CKM
phenomenology and on the indirect search for supersymmetry. We also briefly
discuss direct CP violation in inclusive rare B decays, as well as the rare
kaon decays $K^+\to \pi^+\nu\bar{\nu}$ and $K_L \to \pi^0 \nu \bar{\nu}$, which
offer complementary theoretically clean information.


title:
Cosmological Baryon Asymmetry and Neutrinos: Baryogenesis via
  Leptogenesis in Supersymmetric Theories

abstract:
  Leptogenesis in supersymmetric model is discussed comprehensively and in
detail. In the first half, we discuss several leptogenesis mechanisms by the
decay of heavy right-handed neutrino, which include the standard thermal
leptogenesis, leptogenesis via inflaton decay, and leptogenesis from the
coherent oscillation of the right-handed sneutrino. In the second half, we
perform a detailed analysis on the leptogenesis via the LHu flat direction
(Affleck-Dine leptogenesis).


title:
Erratum: Next-to-leading order supersymmetric QCD predictions for
  associated production of gauginos and gluinos [Phys. Rev. D 62, 095014
  (2000)]

abstract:
  Errors in the published version of the paper are corrected, and new figures
are provided.


title: Opaque Branes in Warped Backgrounds

abstract:
  We examine localized kinetic terms for gauge fields which can propagate into
compact, warped extra dimensions. We show that these terms can have a relevant
impact on the values of the Kaluza-Klein (KK) gauge field masses, wave
functions, and couplings to brane and bulk matter. The resulting
phenomenological implications are discussed. In particular, we show that the
presence of opaque branes, with non-vanishing brane-localized gauge kinetic
terms, allow much lower values of the lightest KK mode than in the case of
transparent branes. Moreover, we show that if the large discrepancies among the
different determinations of the weak mixing angle would be solved in favor of
the value obtained from the lepton asymmetries, bulk electroweak gauge fields
in warped-extra dimensions may lead to an improvement of the agreement of the
fit to the electroweak precision data for a Higgs mass of the order of the weak
scale and a mass of the first gauge boson KK excitation most likely within
reach of the LHC.


title: Dispersion Relations and Inconsistency of $\rho$ data

abstract:
  The high energy elastic nucleon cross section is treated from the viewpoint
of the basic principles of local field theory.
  The connection between the energy dependence of $\sigma_{tot}$ and the $\rho$
- ratio of the real to imaginary parts of the forward elastic scattering
amplitude is examined in the framework of dispersion relations, derivative
dispersion relations and crossing symmetry.


title: Rare and forbidden decays

abstract:
  In these lectures I first cover radiative and semileptonic B decays,
including the QCD corrections for the quark subprocesses. The exclusive modes
and the evaluation of the hadronic matrix elements, i.e. the relevant hadronic
form factors, are the second step. Small effects due to the long-distance,
spectator contributions, etc. are discussed next. The second section we started
with non-leptonic decays, typically $B \to \pi\pi, K\pi, \rho\pi,...$ We
describe in more detail our prediction for decays dominated by the $b\to s
\eta_c$ transition. Reports on the most recent experimental results are given
at the end of each subsection.
  In the second part of the lectures I discuss decays forbidden by the Lorentz
and gauge invariance, and due to the violation of the angular moment
conservation, generally called the Standard Model-forbiden decays. However, the
non-commutative QED and/or non-commutative Standard Model (NCSM), developed in
a series of works in the last few years allow some of those decay modes. These
are, in the gauge sector, $Z\to \gamma\gamma, gg$, and in the hadronic sector,
flavour changing decays of the type $K\to \pi \gamma$, $B\to K\gamma$, etc. We
shall see, for example, that the flavour changing decay $D^+_s\to \pi^+ \gamma$
dominates over other modes, because the processes occur via charged currents,
i.e. on the quark level it arises from the point-like photon $\times$ current
$\times$ current interactions. In the last section we present the transition
rate of ``transverse plasmon'' decay into a neutrino--antineutrino pair via
noncommutative QED, i.e. $\gamma_{\rm pl}\to \nu\bar\nu$. Such decays gives
extra contribution to the mechanism for the energy loss in stars.


title:
The scalar-isoscalar spectral function of strong matter in a large N
  approximation

abstract:
  The enhancement of the scalar-isoscalar spectral function near the two-pion
threshold is studied in the framework of an effective linear $\sigma$ model,
using a large N approximation in the number of the Goldstone bosons. The effect
is rather insensitive to the detailed T=0 characteristics of the $\sigma$ pole,
it is accounted by a pole moving with increasing $T$ along the real axis of the
second Riemann sheet towards the threshold location from below.


abstract:
  We calculate the amplitude of pi-eta scattering in generalized chiral
perturbation theory at the order O(p^4) and present preliminary results of the
numerical analysis of the S-wave scattering length, which seems to be
particularly sensitive to the deviations from the standard case.


title:
Nonequilibrium evolution of Phi**4 theory in 1+1 dimensions in the 2PPI
  formalism

abstract:
  We consider the out-of-equilibrium evolution of a classical condensate field
and its quantum fluctuations for a Phi**4 model in 1+1 dimensions with a
symmetric and a double well potential. We use the 2PPI formalism and go beyond
the Hartree approximation by including the sunset term. In addition to the mean
field phi=<Phi> the 2PPI formalism uses as variational parameter a time
dependent mass M**2(t) which contains all local insertions into the Green
function. We compare our results to those obtained in the Hartree
approximation. In the symmetric Phi**4 theory we observe that the mean field
shows a stronger dissipation than the one found in the Hartree approximation.
The dissipation is roughly exponential in an intermediate time region. In the
theory with spontaneous symmetry breaking, i.e., with a double well potential,
the field amplitude tends to zero, i.e., to the symmetric configuration. This
is expected on general grounds: in 1+1 dimensional quantum field theory there
is no spontaneous symmetry breaking for T >0, and so there should be none at
finite energy density (microcanonical ensemble), either. Within the time range
of our simulations the momentum spectra do not thermalize and display
parametric resonance bands.


title: High-energy spin effects and structure of elastic scattering amplitude

abstract:
  A behavior of imaginary and real parts of the high-energy elastic hadron
scattering amplitude is examined in the diffraction region. It is shown that
the interference between Coulomb and hadronic scattering at small momentum
transfers and especially in the region of diffractive minimum can bring some
information about the structure of the hadron spin-non-flip amplitude.


title:
Important configurations for NN processes in a Goldstone boson exchange
  model

abstract:
  We study the short-range nucleon-nucleon interaction in a nonrelativistic
chiral constituent quark model by diagonalizing a Hamiltonian containing a
linear confinement and a Goldstone boson exchange interaction between quarks. A
finite six-quark basis obtained from single particle cluster model states was
previously used. Here we show that the configurations which appear naturally
through the use of molecular orbitals, instead of cluster model states, are
much more efficient in lowering the six-quark energy.


title: Two-loop QCD corrections for 2 to 2 parton scattering processes

abstract:
  A summary is presented of the most recent matrix elements for massless 2 to 2
scattering processes calculated at two loops in QCD perturbation theory
together with a brief review on the calculational methods and techniques used.


title: QCD Saturation and Deuteron-Nucleus Collisions

abstract:
  We make quantitative predictions for the rapidity and centrality dependencies
of hadron multiplicities in dA collisions at RHIC basing on the ideas of parton
saturation in the Color Glass Condensate.


title: Breaking rotational symmetry in two-flavor color superconductors

abstract:
  The color superconductivity under flavor asymmetric conditions relevant to
the compact star phenomenology is studied within the Nambu-Jona-Lasinio model.
We focus on the effect of the deformation of the Fermi surfaces on the pairing
properties and the energy budget of the superconducting state. We find that at
finite flavor asymmetries the color superconducting BCS state is unstable
towards spontaneous quadrupole deformation of the Fermi surfaces of the $d$ and
$u$ quarks into ellipsoidal form. The ground state of the phase with deformed
Fermi surfaces corresponds to a superposition of prolate and oblate deformed
Fermi ellipsoids of $d$ and $u$ quarks.


title:
Power corrections to the space-like transition form factor
  F_{\eta^{\prime}g^{*}g^{*}}(Q^2,\omega)

abstract:
  Employing the standard hard-scattering approach (HSA) in conjunction with the
running-coupling (RC) method, the latter joined with the infrared-renormalon
calculus, we compute power-suppressed corrections $\sim 1/Q^{2n}, n=1, 2,...$
to the massless $\eta^{\prime}$ meson - virtual gluon transition form factor
(FF) $Q^2F_{\eta ^{\prime}g^{*}g^{*}}(Q^2,\omega)$. Contributions to the form
factor from the quark and gluon components of the $\eta^{\prime}$ meson are
taken into account. Analytic expressions for the FF's
$F_{\eta^{\prime}gg^{*}}(Q^2,\omega=\pm 1)$ and
$F_{\eta^{\prime}g^{*}g^{*}}(Q^2,\omega=0)$ are also presented, as well as
Borel transforms $B[Q^{2}F_{\eta^{\prime}g^{*}g^{*}}](u)$ and resummed
expressions. It is shown that except for $\omega=\pm 1, 0$, the Borel transform
contains an infinite number of infrared renormalon poles. It is demonstrated
that in the explored range of the total gluon virtuality $1 \rm {GeV}^{2} \leq
Q^2 \leq 25 \rm {GeV}^{2}$, power corrections found with the RC method
considerably enhance the FF $F_{\eta^{\prime}g^{*}g^{*}}(Q^{2}, \omega)$
relative to results obtained only in the context of the standard HSA with a
``frozen'' coupling.


title:
MS Versus Pole Masses of Gauge Bosons II: Two-Loop Electroweak Fermion
  Corrections

abstract:
  We have calculated the fermion contributions to the shift of the position of
the poles of the massive gauge boson propagators at two-loop order in the
Standard Model. Together with the bosonic contributions calculated previously
the full two-loop corrections are available. This allows us to investigate the
full correction in the relationship between MS and pole masses of the vector
bosons Z and W. Two-loop renormalization and the corresponding renormalization
group equations are discussed. Analytical results for the master-integrals
appearing in the massless fermion contributions are given. A new approach of
summing multiple binomial sums has been developed.