title: On the thermal footsteps of Neutralino relic gases

abstract:
  Current literature suggests that neutralinos are the dominant cold dark
matter particle species. Assuming the microcanonical definition of entropy, we
examine the local entropy per particle produced between the ``freeze out'' era
to the present. An ``entropy consistency'' criterion emerges by comparing this
entropy with the entropy per particle of actual galactic structures given in
terms of dynamical halo variables. We apply this criterion to the cases when
neutralinos are mosly b-inos and mostly higgsinos, in conjunction with the
usual ``abundance'' criterion requiring that present neutralino relic density
complies with $0.1 < \Omega_{\chic{\tilde\chi^0_1}} < 0.3$ for $h\simeq 0.65$.
The joint application of both criteria reveals that a better fitting occurs for
the b-ino channels, hence the latter seem to be favoured over the higgsino
channels. The suggested methodology can be applied to test other annihilation
channels of the neutralino, as well as other particle candidates of thermal
gases relics.


title: Magnus Expansion and Three-Neutrino Oscillations in Matter

abstract:
  We present a semi-analytical derivation of the survival probability of solar
neutrinos in the three generation scheme, based on the Magnus approximation of
the evolution operator of a three level system, and assuming a mass hierarchy
among neutrino mass eigenstates. We have used an exponential profile for the
solar electron density in our approximation. The different interesting density
regions that appear throughout the propagation are analyzed. Finally, some
comments on the allowed regions in the solar neutrino parameter space are
addressed.


title: Saturation of optimality limits in hadron-hadron scatterings

abstract:
  In this paper the optimal unitarity lower bound on logarithmic slope of the
diffraction peak is investigated. It is shown that the unitarity lower bound is
just the optimal logarithmic slopes predicted by the principle of least
distance in space of states. A systematic tendency towards the saturation of
the most forward-peaked limit is observed from all the available experimental
data of all principal hadron-hadron (e.g., antiproton-proton, proton-proton,
kaon-proton, pion-proton) scatterings practically at all laboratory momenta.


title: A Unified Approach to High Density: Pion Fluctuations in Skyrmion Matter

abstract:
  As the first in a series of systematic work on dense hadronic matter, we
study the properties of the pion in dense medium using Skyrme's effective
Lagrangian as a unified theory of the hadronic interactions applicable in the
large $N_c$ limit. Dense baryonic matter is described as the ground state of a
skyrmion matter which appears in two differentiated phases as a function of
matter density: i) at high densities as a stable cubic-centered (CC)
half-skyrmion crystal; ii) at low densities as an unstable face-centered cubic
(FCC) skyrmion crystal. We substitute the latter by a stable inhomogeneous
phase of lumps of dense matter, which represents a naive Maxwell construction
of the phase transition. This baryonic dense medium serves as a background for
the pions whose effective {\em in-medium} Lagrangian we construct by allowing
time-dependent quantum fluctuations on the classical dense matter field. We
find that the same parameter which describes the phase transition for baryonic
matter, the expectation value of the $\sigma$ field, also describes the phase
transition for the dynamics of the {\em in-medium} pion. Thus, the structure of
the baryonic ground state $crucially$ determines the behavior of the pion in
the medium. As matter density increases, $<\sigma>$ decreases, a phenomenon
which we interpret to signal, in terms of the parameters of the effective pion
Lagrangian $f_\pi^*$ and $m_\pi^*$, the restoration of chiral symmetry at high
density. Our calculation shows also the important role played by the higher
powers in the density as it increases and chiral symmetry is being restored.
This feature is likely to be generic at high density although our ground state
may not be the true ground state.


title: Particle Aspects of Cosmology and Baryogenesis

abstract:
  An introduction to particle aspects of cosmology with particular refrence to
primordial nucleosynthesis, dark matter and baryogenesis is provided. In
particular, various scenarios-GUT baryogenesis, electroweak baryogenesis and
baryogenesis through leptogenesis are reviewed.


title:
Solar Neutrino Masses and Mixing from Bilinear R-Parity Broken
  Supersymmetry: Analytical versus Numerical Results

abstract:
  We give an analytical calculation of solar neutrino masses and mixing at
one-loop order within bilinear R-parity breaking supersymmetry, and compare our
results to the exact numerical calculation. Our method is based on a systematic
perturbative expansion of R-parity violating vertices to leading order. We find
in general quite good agreement between approximate and full numerical
calculation, but the approximate expressions are much simpler to implement. Our
formalism works especially well for the case of the large mixing angle MSW
solution (LMA-MSW), now strongly favoured by the recent KamLAND reactor
neutrino data.


title:
Deep inelastic $J/\psi$ production at HERA in the $k_T$-factorization
  approach and its consequences for the nonrelativistic QCD

abstract:
  In the framework of the $k_T$-factorization approach, we analyse the
inclusive and inelastic production of $J/\psi$ particles in deep inelastic $ep$
scattering. We take into account both colour-singlet and colour-octet
production channels. We inspect the sensitivity of theoretical predictions to
the choice of model parameters. Our theoretical results agree reasonably well
with recent experimental data collected by the collaboration H1 at HERA.


title: Gauge and Lorentz Covariant Quark Propagator in an Arbitrary Gluon Field

abstract:
  The quark propagator in presence of an arbitrary gluon field is calculated
gauge and Lorentz covariantly order by order in terms of powers of gluon field
and its derivatives. The result is independent of path connecting ends of
propagator and leading order result coincides with the exact propagator in the
trivial case of vanishing gluon field.


title: Supersymmetry Physics at Linear Colliders

abstract:
  The experimental potential of e+e- Linear Colliders to explore the properties
of supersymmetric particles is reviewed. High precision measurements of masses,
spin-parity, gauge quantum numbers, couplings and mixings, production and decay
properties will be possible in a clean environment. These achievements will
allow the underlying supersymmetry breaking scheme to be revealed, the
parameters of the fundamental theory to be determined and to test their
unification through extrapolation to very high energie scales.


title:
Permutation Symmetry, Tri-Bimaximal Neutrino Mixing and the S3 Group
  Characters

abstract:
  We postulate that the neutrino mass matrix in the lepton flavour basis is an
S3 group matrix in the natural representation of S3. This immediately requires
one neutrino to be trimaximally mixed, as suggested by the solar neutrino data.
We go on to postulate that the charged-lepton mass matrix in the neutrino
mass-basis is an S3 class matrix in the natural representation of the S3
class-algebra, leading to exact tri-bimaximal mixing, which is compatible with
data overall. The tri-bimaximal mixing matrix is seen to be closely related to
the S3 character table, and is properly the S2 C S3 table of induction
coefficients, where the S2 corresponds to symmetry under mu-tau interchange in
the lepton flavour basis.


title: Coherence and Wave Packets in Neutrino Oscillations

abstract:
  General arguments in favor of the necessity of a wave packet description of
neutrino oscillations are presented, drawing from analogies with other wave
phenomena. We present a wave packet description of neutrino oscillations in
stationary beams using the density matrix formalism. Recent claims of the
necessity of an equal energy of different massive neutrinos are refuted.


title: A Natural Framework for Bi-large Neutrino Mixing

abstract:
  In this letter we present a "natural" framework for obtaining bi-large
neutrino mixing incorporating the FGY neutrino mass matrix ansatz. We show that
an $SU(2) \times U(1)$ family symmetry can provide the desired FGY neutrino
mass ansatz in the MSSM. We also show how to obtain an approximate FGY ansatz
in an SO(10) SUSY GUT. In this context, the same $SU(2) \times U(1)$ family
symmetry also generates the hierarchy of fermion masses as well as ameliorating
SUSY flavor problems.


title: Lorentz invariance relations among parton distributions revisited

abstract:
  We revisit the derivation of the so-called Lorentz invariance relations
between parton distributions. In the most important cases these relations
involve twist-3 and transverse momentum dependent parton distributions. It is
shown that these relations are violated if the path-ordered exponential is
taken into account in the quark correlator.


title:
Combined effect of coherent Z exchange and the hyperfine interaction in
  atomic PNC

abstract:
  The nuclear spin-dependent parity nonconserving (PNC) interaction arising
from a combination of the hyperfine interaction and the coherent,
spin-independent, PNC interaction from Z exchange is evaluated using many-body
perturbation theory. For the 6s-7s transition in 133Cs, we obtain a result that
is about 40% smaller than that found previously by Bouchiat and Piketty [Phys.
Lett. B 269, 195 (1991)]. Applying this result to 133Cs, leads to an increase
in the experimental value of nuclear anapole moment and exacerbates differences
between constraints on PNC meson coupling constants obtained from the Cs
anapole moment and those obtained from other nuclear parity violating
experiments. Nuclear spin-dependent PNC dipole matrix elements, including
contributions from the combined weak-hyperfine interaction, are also given for
the 7s-8s transition in 211Fr and for transitions between ground-state
hyperfine levels in K, Rb, Cs, Ba+, Au, Tl, Fr, and Ra+.


title: Super-GZK Photons from Photon-Axion Mixing

abstract:
  We show that photons with energies above the GZK cutoff can reach us from
very distant sources if they mix with light axions in extragalactic magnetic
fields. The effect which enables this is the conversion of photons into axions,
which are sufficiently weakly coupled to travel large distances unimpeded.
These axions then convert back into high energy photons close to the Earth. We
show that photon-axion mixing facilitates the survival of super-GZK photons
most efficiently with a photon-axion coupling scale of order 10^11 GeV, which
is in the same range as the scale for the photon-axion mixing explanation for
the dimming of supernovae without cosmic acceleration. We discuss possible
observational consequences of this effect.


title: Introduction to Heavy Meson Decays and CP Asymmetries

abstract:
  These lectures are intended to provide an introduction to heavy meson decays
and CP violation. The first lecture contains a brief review of the standard
model and how the CKM matrix and CP violation arise, mixing and CP violation in
neutral meson systems, and explanation of the cleanliness of the sin(2beta)
measurement. The second lecture deals with the heavy quark limit, some
applications of heavy quark symmetry and the operator product expansion for
exclusive and inclusive semileptonic B decays. The third lecture concerns with
theoretically clean CP violation measurements that may become possible in the
future, and some developments toward a better understanding of nonleptonic B
decays. The conclusions include a subjective best buy list for the near future.


title:
Direct Detection of Dark Matter in the MSSM with Non-Universal Higgs
  Masses

abstract:
  We calculate dark matter scattering rates in the minimal supersymmetric
extension of the Standard Model (MSSM), allowing the soft
supersymmetry-breaking masses of the Higgs multiplets, m_{1,2}, to be
non-universal (NUHM). Compared with the constrained MSSM (CMSSM) in which
m_{1,2} are required to be equal to the soft supersymmetry-breaking masses m_0
of the squark and slepton masses, we find that the elastic scattering cross
sections may be up to two orders of magnitude larger than values in the CMSSM
for similar LSP masses. We find the following preferred ranges for the
spin-independent cross section: 10^{-6} pb \ga \sigma_{SI} \ga 10^{-10} pb, and
for the spin-dependent cross section: 10^{-3} pb \ga \sigma_{SD}, with the
lower bound on \sigma_{SI} dependent on using the putative constraint from the
muon anomalous magnetic moment. We stress the importance of incorporating
accelerator and dark matter constraints in restricting the NUHM parameter
space, and also of requiring that no undesirable vacuum appear below the GUT
scale. In particular, values of the spin-independent cross section another
order of magnitude larger would appear to be allowed, for small \tan \beta, if
the GUT vacuum stability requirement were relaxed, and much lower cross-section
values would be permitted if the muon anomalous magnetic moment constraint were
dropped.


title: Probing the neutrino mass hierarchy and the 13-mixing with supernovae

abstract:
  We consider in details the effects of the 13-mixing (sin^2 theta_{13}) and of
the type of mass hierarchy/ordering (sign[ Delta m^2_{13}]) on neutrino signals
from the gravitational collapses of stars. The observables (characteristics of
the energy spectra of nu_e and antinu_e events) sensitive to sin^2 theta_{13}
and sign[Delta m^2_{13}] have been calculated. They include the ratio of
average energies of the spectra, r_E = <E>/<\bar E >, the ratio of widths of
the energy distributions, r_Gamma, the ratios of total numbers of nu_e and
antinu_e events at low energies, S, and in the high energy tails, R_{tail}. We
construct and analyze scatter plots which show the predictions for the
observables for different intervals of sin^2 theta_{13} and signs of Delta
m^2_{13}, taking into account uncertainties in the original neutrino spectra,
the star density profile, etc.. Regions in the space of observables r_E,
r_Gamma, S, R_{tail} exist in which certain mass hierarchy and intervals of
sin^2 theta_{13} can be identified or discriminated. We elaborate on the method
of the high energy tails in the spectra of events. The conditions are
formulated for which sin^2 theta_{13} can be (i) measured, (ii) restricted from
below, (iii) restricted from above. We comment on the possibility to determine
sin^2 theta_{13} using the time dependence of the signals due to the
propagation of the shock wave through the resonance layers of the star. We show
that the appearance of the delayed Earth matter effect in one of the channels
(nu_e or antinu_e) in combination with the undelayed effect in the other
channel will allow to identify the shock wave appeareance and determine the
mass hierarchy.


title: Neutrino Mass Matrix Predicted From Symmetric Texture

abstract:
  Within the framework of grand unified theories, we make full analysis of
symmetric texture to see if such texture can reproduce large neutrino mixings,
which have recently been confirmed by the observed solar and atmospheric
neutrino oscillation experiments. It is found that so-called symmetric texture
with anomalous U(1) family symmetry with Froggatt-Nielsen mechanism does not
provide a natural explanation of two large mixing angles. On the contrary we
should adopt "zero texture" which have been extensively studied by many authors
and only this scenario can reproduce two large mixing angles naturally. Under
such "zero texture" with minimal symmetric Majorana matrix, all the neutrino
masses and mixing angles, 6 quantities, are expressed in terms of up-quark
masses, $m_t,m_c,m_u$ with two adjustable parameters. This provides interesting
relations among neutrio mixing angles, $\tan^2 2\theta_{12} \simeq
\frac{144m_c}{m_t} \tan^2 2\theta_{23} \cos^2 \theta_{23}, \quad \sin^2
\theta_{13} \simeq \frac{4m_c}{m_t}\sin^2 \theta_{23} \cos^2 \theta_{12}$. Thus
$|U_{e3}|$ is predicted to lie within the range $0.01-0.06$. Also absolute
masses of three neutrinos are predicted almost uniquely. This is quite in
contrast to the case where bi-large mixings come from the charged lepton sector
with non-symmetric mass matrix, which does not provide the information of
neutrino masses.


title: Non-tachyonic brane inflation

abstract:
  We consider non-tachyonic hybrid inflation in the context of the braneworld
cosmology. When one considers models for brane inflation, hybrid inflation is a
natural consequence of the tachyon condensation if it appears at the end of
inflation. In this case, however, reheating is a difficult problem due to the
peculiar properties of the tachyon. In this paper we show some models for brane
inflation where a new type of hybrid inflation is realized due to the localized
matter fields. The obvious advantage of our scenario is successful reheating,
which is due to the potential that is localized on the brane. The serious
problem of the loop correction is also avoided.


title:
Clustering, GUT scale and neutrino masses from ultrahigh energy cosmic
  rays

abstract:
  The origin of highest energy cosmic rays (UHECR) is yet unknown. In order to
understand their propagation we determine the probability that an ultrahigh
energy (above 5\cdot 10^{19} eV) proton created at a distance r with energy E
arrives at earth above a threshold E_c. The clustering of ultrahigh energy
cosmic rays suggests that they might be emitted by compact sources. A
statistical analysis on the source density based on the multiplicities is
presented. The ultrahigh energy cosmic ray spectrum is consistent with the
decay of GUT scale particles. Alternatively, we consider the possibility that a
large fraction of the ultrahigh energy cosmic rays are decay products of Z
bosons which were produced in the scattering of ultrahigh energy cosmic
neutrinos on cosmological relic neutrinos. Based on this scenario we determine
the required mass of the heaviest relic neutrino. The required ultrahigh energy
neutrino flux should be detected in the near future by experiments such as
AMANDA, RICE or the Pierre Auger Observatory.


title:
$B^0(\pm)$ decays into two vector mesons. Physical motivations and a
  general method for simulations

abstract:
  In this paper, a complete description of the channels $B \to V_1 V_2$ is
given. Emphasis is put on the determination of the dynamical density matrix
which elements are computed according to the Wilson operator product expansions
entering into the formulation of the weak effective hamiltonian. \vskip 0.3cm
Kinematical consequences related to the particular channel $B \to K^* {\rho}^0
(\omega)$ are described in details.


title: Precursors From $S^{(1)}/Z_2\tm Z_2'$ Orbifold GUTs

abstract:
  The possibility of appearance of GUT precursors near the TeV scale (suggested
by Dienes-Dudas-Gherghetta) is addressed within 5D GUTs compactified on an
$S^{(1)}/Z_2\tm Z_2'$ orbifold. For a low compactification scale (large
radius), there is a significant non universal logarithmic contribution in the
relative running of gauge couplings. This within 5D SU(5), with the minimal
field content, gives wrong prediction for $\al_3(M_Z)$ unless one goes beyond
the minimal setting. The realization of the light precursors' idea thus
requires some specific extensions. As a scenario alternative to SU(5) we also
consider an SU(6) orbifold GUT, whose minimal non SUSY version gives natural
unification. In all the presented unification scenarios with light precursors,
various GUT scales are realized. This allows the model to be naturally embedded
in either heterotic or Type ${\rm I}$ string theories.


title:
Probing the LSND scale and four neutrino scenarios with a neutrino
  telescope

abstract:
  We show in this paper that the observation of the angular distribution of
upward-going muons and cascade events induced by atmospheric neutrinos at the
TeV energy scale, which can be performed by a kilometer-scale neutrino
telescope, such as the IceCube detector, can be used to probe a large neutrino
mass splitting, $| \Delta m^2 | \sim (0.5-2.0)$ eV$^2$, implied by the LSND
experiment and discriminate among four neutrino mass schemes. This is due to
the fact that such a large mass scale can promote non negligible muon neutrino
to electron/tau neutrino (and/or anti-muon neutrino to anti-electron/anti-tau
neutrino) conversions at these energies by the MSW effect as well as vacuum
oscillation, unlike what is expected if all the neutrino mass splittings are
small.


title: Threshold effects in excited charmed baryon decays

abstract:
  Motivated by recent results on charmed baryons from CLEO and FOCUS, we
reexamine the couplings of the orbitally excited charmed baryons. Due to its
proximity to the [Sigma_c pi] threshold, the strong decays of the
Lambda_c(2593) are sensitive to finite width effects. This distorts the shape
of the invariant mass spectrum in Lambda_{c1}-> Lambda_c pi^+pi^- from a simple
Breit-Wigner resonance, which has implications for the experimental extraction
of the Lambda_c(2593) mass and couplings. We perform a fit to unpublished CLEO
data which gives M(Lambda_c(2593)) - M(Lambda_c) = 305.6 +- 0.3 MeV and h2^2 =
0.24^{+0.23}_{-0.11}, with h2 the Lambda_{c1}-> Sigma_c pi strong coupling in
the chiral Lagrangian. We also comment on the new orbitally excited states
recently observed by CLEO.


title: Brane-world dark matter

abstract:
  We show that, in the context of brane-world scenarios with low tension
$\tau=f^4$, massive brane fluctuations are natural dark matter candidates. We
calculate the present abundances for both hot(warm) and cold branons in terms
of the branon mass $M$ and the tension scale $f$. The results are compared with
the current experimental bounds on these parameters. We also study the
prospects for their detection in direct search experiments and comment on their
characteristic signals in the indirect ones.


title: SU(4) Chiral Quark Model with Configuration Mixing

abstract:
  Chiral quark model with configuration mixing and broken SU(3)\times U(1)
symmetry has been extended to include the contribution from c\bar c
fluctuations by considering broken SU(4) instead of SU(3). The implications of
such a model have been studied for quark flavor and spin distribution functions
corresponding to E866 and the NMC data. The predicted parameters regarding the
charm spin distribution functions, for example, \Delta c, \frac{\Delta
c}{{\Delta \Sigma}}, \frac{\Delta c}{c} as well as the charm quark distribution
functions, for example, \bar c, \frac{2\bar c}{(\bar u+\bar d)}, \frac{2 \bar
c}{(u+d)} and \frac{(c+ \bar c)}{\sum (q+\bar q)} are in agreement with other
similar calculations. Specifically, we find \Delta c=-0.009, \frac{\Delta
c}{{\Delta \Sigma}}=-0.02, \bar c=0.03 and \frac{(c+ \bar c)}{\sum (q+\bar
q)}=0.02 for the \chiQM parameters a=0.1, \alpha=0.4, \beta=0.7,
\zeta_{E866}=-1-2 \beta, \zeta_{NMC}=-2-2 \beta and \gamma=0.3, the latter
appears due to the extension of SU(3) to SU(4).


title: QCD Form Factors and Hadron Helicity Non-Conservation

abstract:
  Recent data for the ratio $R(Q)= QF_{2}(Q^{2})/F_{1}(Q^{2})$ shocked the
community by disobeying expectations held for 50 years. We examine the status
of perturbative QCD predictions for helicity-flip form factors. Contrary to
common belief, we find there is no rule of hadron helicity conservation for
form factors. Instead the analysis yields an inequality that the leading power
of helicity-flip processes may equal or exceed the power of helicity conserving
processes. Numerical calculations support the rule, and extend the result to
the regime of laboratory momentum transfer $Q^{2}$. Quark orbital angular
momentum, an important feature of the helicity flip processes, may play a role
in all form factors at large $Q^{2}$, depending on the quark wave functions.


title:
Two-photon decay rates of heavy quarkonia in the relativistic quark
  model

abstract:
  Two-photon decay rates of pseudoscalar, scalar and tensor states of
charmonium and bottomonium are calculated in the framework of the relativistic
quark model. Both relativistic effects and one-loop radiative corrections are
taken into account. The obtained results are compared with other theoretical
predictions and available experimental data.


title: Coherence in Neutrino Interactions

abstract:
  The claim in hep-ph/0301231 is refuted in a pedagogical way. It is explicitly
shown that extremely relativistic neutrinos produced in pion decay are
correctly described by the standard flavor neutrino states which are a coherent
superposition of massive neutrino states.


title:
Measuring the Higgs boson parity at a Linear Collider using the tau
  impact parameter and tau --> rho nu decay

abstract:
  We demonstrate that a measurement of the impact parameter in one-prong tau
decay can be useful for the determination of the Higgs boson parity in the H/A
--> tau tau; tau --> rho nu decay chain. We have estimated that for a detection
set-up such as TESLA, use of the information from the tau impact parameter can
improve the significance of the measurement of the parity of the Standard Model
120 GeV Higgs boson to 4.5 sigma, and in general by factor of about 1.5 with
respect to the method where this information is not used.
  We also show that the variation in the assumption on the precision of the
measurement of the impact parameter and/or pi's momenta does not affect the
sensitivity of the method. This is because the method remains limited by the
type of twofold ambiguity in reconstructing the tau momentum.


title:
Infrared behavior of the running coupling constant and quarkonium
  spectrum

abstract:
  We study the effect of the infrared behavior of the running coupling constant
on the quark-antiquark spectrum.


title: Odderon induced Pion-Photoproduction at e+e- Colliders

abstract:
  In diffractive hadronic scattering processes, the Pomeron trajectory,
originating from Regge theory, significantly contributes to the behavior of the
total and differential cross sections; the same holds for the description of
the proton structure function in deep inelastic scattering. So far, the Odderon
as the odd-parity partner of the Pomeron has only been observed in differences
between differential cross sections for p p and p pbar scattering at low t. We
investigate exclusive photoproduction of two neutral pion final states at e+e-
colliders; in this reaction, Pomeron exchange is forbidden by C-parity
conservation. The Odderon is described by an effective propagator. The Odderon
contribution produces significant modifications of the differential cross
sections. We investigate the effects of variation of trajectory and coupling
parameters. We provide numerical results for total and differential cross
sections for OPAL, BaBar, TESLA and the TESLA photon collider including
detector cuts.


title: The Little Higgs from a Simple Group

abstract:
  We present a model of electroweak symmetry breaking in which the Higgs boson
is a pseudo-Nambu-Goldstone boson. By embedding the standard model SU(2) x U(1)
into an SU(4) x U(1) gauge group, one-loop quadratic divergences to the Higgs
mass from gauge and top loops are canceled automatically with the minimal
particle content. The potential contains a Higgs quartic coupling which does
not introduce one-loop quadratic divergences. Our theory is weakly coupled at
the electroweak scale, it has new weakly coupled particles at the TeV scale and
a cutoff above 10 TeV, all without fine tuning. We discuss the spectrum of the
model and estimate the constraints from electroweak precision measurements.


title: Quarkonium Formation from Uncorrelated Quark-Antiquark Pairs

abstract:
  The goal of this section is to assess the possibility that quarkonium
production rates may be enhanced in nucleus-nucleus interactions at the LHC
relative to that predicted by extrapolation of processes thought to be dominant
at lower energy. This enhancement could follow from the effects of incoherent
recombination mechanisms involving uncorrelated pairs of heavy quarks and
antiquarks which result from multiple pair production. Two different approaches
have been considered: statistical hadronization and kinetic formation. Updated
predictions relevant to Pb+Pb collisions at the LHC are given.


title: Fermionic NNLL corrections to b -> s \gamma

abstract:
  In this paper we take the first step towards a complete
next-to-next-to-leading logarithmic (NNLL) calculation of the inclusive decay
rate for $B \to X_s\gamma$. We consider the virtual corrections of order
$\alphas^2 n_f$ to the matrix elements of the operators ${O}_1$, ${O}_2$ and
${O}_8$ and evaluate the real and virtual contributions to ${O}_7$. These
corrections are expected to be numerically important. We observe a strong
cancelation between the contributions from the current-current operators and
$O_7$ and obtain, after applying naive non-abelianization, a reduction of the
branching ratio of 3.9% (for $\mu=3.0$ GeV) and an increase of 3.4% (for
$\mu=9.6$ GeV).


title: Formation of antideuterons in heavy ion collisions

abstract:
  The antideuteron production rate at high-energy heavy ions collisions is
calculated basing on the concept of anti-d formation by antinucleons which move
in the mean field of the fireball constituents (mainly pions). The explicit
formula is presented for the coalescence parameter B_2 in terms of deuteron
binding energy and fireball volume.


title:
Consistency in NLO analyses of inclusive and semi-inclusive polarized
  DIS data

abstract:
  We perform a detailed study of the consistency between different sets of
polarized deep inelastic scattering data and theory, from the standpoint of a
next to leading order QCD global analysis, and following the criteria proposed
by Collins and Pumplin. In face of recent suggestions that challenge the usual
assumption about parent parton spin independence of unpolarized fragmentation
functions, we specially focus on polarized semi-inclusive data.


title:
On the Connection of Leptogenesis with Low Energy CP Violation and LFV
  Charged Lepton Decays

abstract:
  Assuming only a hierarchical structure of the heavy Majorana neutrino masses
and of the neutrino Dirac mass matrix m_D of the see-saw mechanism, we find
that in order to produce the observed baryon asymmetry of the Universe via
leptogenesis, the scale of m_D should be given by the up-quark masses. Lepton
flavor violating decays \mu \to e + \gamma, \tau \to \mu + \gamma and \tau \to
e + \gamma are considered and a characteristic relation between their decay
rates is predicted. The effective Majorana mass in neutrinoless double beta
decay depends on the CP violating phase controlling the leptogenesis if one of
the heavy Majorana neutrinos is much heavier than the other two. Successful
leptogenesis requires a rather mild mass hierarchy between the latter. The
compatibility of this hierarchical see-saw model with the low energy neutrino
mixing phenomenology requires that the mixing angle limited by the CHOOZ and
Palo Verde experiments should be relatively large, \sin^2\theta_3 \gtap 0.01.
The CP violation effects in neutrino oscillations can be observable. In
general, there is no direct connection between the latter and the CP violation
in leptogenesis. If the CP violating phases of the see-saw model satisfy
certain relations, the baryon asymmetry of the Universe and the rephasing
invariant J_{CP} which determines the magnitude of the CP violation effects in
neutrino oscillations, depend on the same CP violating phase and their signs
are correlated.


title:
Dynamical renormalization group approach to relaxation in quantum field
  theory

abstract:
  The real time evolution and relaxation of expectation values of quantum
fields and of quantum states are computed as initial value problems by
implementing the dynamical renormalization group (DRG).Linear response is
invoked to set up the renormalized initial value problem to study the dynamics
of the expectation value of quantum fields. The perturbative solution of the
equations of motion for the field expectation values of quantum fields as well
as the evolution of quantum states features secular terms, namely terms that
grow in time and invalidate the perturbative expansion for late times. The DRG
provides a consistent framework to resum these secular terms and yields a
uniform asymptotic expansion at long times. Several relevant cases are studied
in detail, including those of threshold infrared divergences which appear in
gauge theories at finite temperature and lead to anomalous relaxation. In these
cases the DRG is shown to provide a resummation akin to Bloch-Nordsieck but
directly in real time and that goes beyond the scope of Bloch-Nordsieck and
Dyson resummations. The nature of the resummation program is discussed in
several examples. The DRG provides a framework that is consistent, systematic
and easy to implement to study the non-equilibrium relaxational dynamics
directly in real time that does not rely on the concept of quasiparticle
widths.


title: Softening the Naturalness Problem

abstract:
  It was observed by Veltman a long time ago that a special value for the Higgs
boson mass could lead to a cancellation of the quadratically divergent
corrections to the Higgs boson's squared mass which appear at one loop. We
present a class of low energy models that allow to soften the naturalness
problem in the sense that there can be a cancellation of radiative corrections
appearing at one loop. The naturalness problem is shifted from the one TeV
region to the 10 TeV region. Depending on the specific model under
consideration, this scale can even be shifted to a higher energy scale.
Signatures of these models are discussed.


title:
Excited tau lepton contribution to $W->tau nu(tau)$ decay at the
  one-loop level

abstract:
  We evaluate the compositeness effects of tau lepton on the vertex
W-tau-nu(tau) in the context of an effective Lagrangian approach. We consider
that only the third family is composed and we get the corrections to the non
universal lepton coupling g_(tau)/g_(e). As the experimental bounds on non
universal lepton couplings in W decays are weak, we find that the excited
particles contributions do not give realistic limits on the excited mass, since
they lead to Lambda<m*.


title: The custodial symmetry

abstract:
  In the present work, we elucidate the meaning of the custodial symmetry and
its importance at the phenomenological level in the framework of the standard
model of the electroweak interactions and its possible extensions.


title:
Evidence for two-quark content of $f_{0}(980)$ in exclusive $b\to c$
  decays

abstract:
  Inspired by a large decay branching ratio (BR) of $B^{+}\to f_{0}(980)K^{+}$
measured by Belle recently, we propose that a significant evidence of the
component of $n\bar{n}=(u\bar{u}+d\bar{d})/\sqrt{2}$ in $f_{0}(980)$ could be
demonstrated in exclusive $b\to c$ decays by the observation of $f_{0}(980)$ in
the final states $\bar{B}\to D^{0(*)} \pi^{+} \pi^{-}(KK)$ and $\bar{B}\to
J/\Psi \pi^{+} \pi^{-}(KK)$. We predict the BRs of $\bar{B}\to D^{0(*)}
(J/\Psi) f_{0}(980)$ to be ${\cal {O}}(10^{-4})$ (${\cal {O}}(10^{-5})$) while
the unknown wave functions of $D^{(*)0}$ ($J/\Psi$) are chosen to fit the
observed decays of $\bar{B}\to D^{(*)0} \pi^{0} (J/\Psi K^{0(*)})$.


title:
Determination of the age of the earth from Kamland measurement of
  geo-neutrinos

abstract:
  The low energy component of the antineutrino spectrum observed in the recent
Kamland experiment has significant contribution from the radioactive decay of
$^{238}U$ and $^{232}Th$ in the crust and mantle of the earth. By taking the
ratio of the antineutrino events obeserved in two different energy ranges we
can determine the present value $[Th/U]$ independent of the U,Th distribution
in the earth. Comparing with the r-process initial value of $[Th/U]_0$ we
determine the age of the earth as a function of $\Delta m^2$ and $Sin^2 2
\theta$. We find that the age of the earth determined from KamLAND data matches
the age of solar system ($4.5 Gyrs$ from meteorites) for the LMA-I solution.
For the LMA-II solution the age of the earth does not match the solar system
age at 90 % C.L.


title:
Double Spin Asymmetries for Large-$p_T$ Hadron Production in
  Semi-Inclusive DIS

abstract:
  We study the twist-2 double-spin asymmetries for the 2-jets and large-$p_T$
hadron ($\pi$, $\Lambda$ etc) production in semi-inclusive deep inelastic
scattering to $O(\alpha_s)$ in perturbative QCD. After deriving the complete
set of the polarized cross section which is differential with respect to the
transverse momentum, we discuss characteristic features of the azymuthal spin
asymmetries, using existing parton densities and fragmentation functions at
COMPASS and EIC energies.


title: S-wave Meson-Meson Scattering from Unitarized U(3) Chiral Lagrangians

abstract:
  An investigation of the s-wave channels in meson-meson scattering is
performed within a U(3) chiral unitary approach. Our calculations are based on
a chiral effective Lagrangian which includes the eta' as an explicit degree of
freedom and incorporates important features of the underlying QCD Lagrangian
such as the axial U(1) anomaly. We employ a coupled channel Bethe-Salpeter
equation to generate poles from composed states of two pseudoscalar mesons. Our
results are compared with experimental phase shifts up to 1.5 GeV and effects
of the eta' within this scheme are discussed.


title: New Physics in CP-Violating Observables for Beauty

abstract:
  After the present establishment of CP-Violation in $B_{d}$-physics,
consistency tests of unitarity in the Standard Model and the search of new
phenomena are compulsory. I illustrate the way to look for T-violation, without
contamination of absorptive parts, in correlated decays in B-factories.
$B_{s}$-mixing and penguin-mediated $B_{s}$-decays are of prime importance in
hadronic machines to look for new physics.


title: Determination of the Anomalous Chiral Coefficients of order $p^{6}$

abstract:
  Symmetries affected by the anomaly do not survive quantization and cannot be
understood classically. They are of fundamental importance and offer an
opportunity of expanding the theoretical framework. We examine the theory of
the anomalous sector, starting from lowest order Chiral Perturbation Theory
(ChPT), leading up to the construction of the recently developed Lagrangian of
$\mathcal{O}(p^{6}) $ describing anomalous processes. This Lagrangian contains
a set of chiral coefficients that must be determined phenomenologically. Using
currently available experimental data, we fit as many of these coefficients as
possible. The results of the ChPT treatment are then used to test the validity
of the two main alternative models employed in the anomalous sector - Vector
Meson Dominance (VMD) and the constituent Chiral Quark Model (CQM).


title: Multiphoton Radiation in Leptonic W-Boson Decays

abstract:
  We present the calculation of multiphoton radiation effects in leptonic
W-boson decays in the framework of the Yennie-Frautschi-Suura exclusive
exponentiation. This calculation is implemented in the Monte Carlo event
generator WINHAC for single W-boson production in hadronic collisions at the
parton level. Some numerical results obtained with the help of this program are
also presented.


title: Primordial Nucleosynthesis Constraints on Z' Properties

abstract:
  In models involving new TeV-scale Z' gauge bosons, the new U(1)' symmetry
often prevents the generation of Majorana masses needed for a conventional
neutrino seesaw, leading to three superweakly interacting ``right-handed''
neutrinos nu_R, the Dirac partners of the ordinary neutrinos. These can be
produced prior to big bang nucleosynthesis by the Z' interactions, leading to a
faster expansion rate and too much ^4He. We quantify the constraints on the Z'
properties from nucleosynthesis for Z' couplings motivated by a class of E_6
models parametrized by an angle theta_E6. The rate for the annihilation of
three approximately massless right-handed neutrinos into other particle pairs
through the Z' channel is calculated. The decoupling temperature, which is
higher than that of ordinary left-handed neutrinos due to the large Z' mass, is
evaluated, and the equivalent number of new doublet neutrinos Delta N_nu is
obtained numerically as a function of the Z' mass and couplings for a variety
of assumptions concerning the Z-Z' mixing angle and the quark-hadron transition
temperature T_c. Except near the values of theta_E6 for which the Z' decouples
from the right-handed neutrinos, the Z' mass and mixing constraints from
nucleosynthesis are much more stringent than the existing laboratory limits
from searches for direct production or from precision electroweak data, and are
comparable to the ranges that may ultimately be probed at proposed colliders.
For the case T_c = 150 MeV with the theoretically favored range of Z-Z'
mixings, Delta N_nu < 0.3 for M_Z' > 4.3 TeV for any value of theta_E6. Larger
mixing or larger T_c often lead to unacceptably large Delta N_nu except near
the nu_R decoupling limit.


title: Static potential in baryon

abstract:
  The baryon static potential is calculated in the framework of field
correlator method and is shown to match the recent lattice results. The effects
of the nonzero value of the gluon correlation length are emphasized.


title: Higgs production and decay in the little Higgs model

abstract:
  We analyse the consequences of the little Higgs model for double Higgs boson
production at the LHC and for the partial decay width of the Higgs into two
photons. In particular, we study the sensitivity of these processes in terms of
the parameters of the model. We find that the little Higgs model contributions
are proportional to (v/f)^4 and hence do not change significantly either single
or double Higgs production at hadron colliders or the partial decay width of
the Higgs into two photons as compared to the standard model predictions.
However, when interference and mixing effects are properly taken into account
these contributions increase to be of the order of (v/f)^2.


title: Two-loop HTL Thermodynamics with Quarks

abstract:
  We calculate the quark contribution to the free energy of a hot quark-gluon
plasma to two-loop order using hard-thermal-loop (HTL) perturbation theory. All
ultraviolet divergences can be absorbed into renormalizations of the vacuum
energy and the HTL quark and gluon mass parameters. The quark and gluon HTL
mass parameters are determined self-consistently by a variational prescription.
Combining the quark contribution with the two-loop HTL perturbation theory free
energy for pure-glue we obtain the total two-loop QCD free energy. Comparisons
are made with lattice estimates of the free energy for N_f=2 and with exact
numerical results obtained in the large-N_f limit.


title: Adiabatic potentials and spectra of heavy hybrid mesons

abstract:
  Using the QCD string approach the adiabatic potentials and spectra of b\bar
b-hybrid mesons are calculated. The results are compared to lattice studies.


title: Triangular and Y-shaped hadrons with static sources

abstract:
  The structure of hadrons consisting of three static color sources in
fundamental (baryons) or adjoint (three-gluon glueballs) representations is
studied. The static potentials of glueballs as well as gluon field
distributions in glueballs and baryons are calculated in the framework of field
correlator method.


title: A short distance quark-antiquark potential

abstract:
  Leading terms of the static quark-antiquark potential in the background
perturbation theory are reviewed, including perturbative, nonperturbative and
interference ones. The potential is shown to describe lattice data at short
quark-antiquark separations with a good accuracy.


title:
Flavor hierarchy in SO(10) grand unified theories via 5-dimensional
  wave-function localization

abstract:
  A mechanism to generate fermion-mass hierarchy in SO(10) Grand Unified
Theories is considered. We find that the lopsided family structure, which is
suitable to the Large angle MSW solution to the solar neutrino oscillation, is
realized without introducing extra matter fields if the hierarchy originates
from the wave-function profile in an extra dimension. Unlike the
Froggatt-Nielsen mechanism, the SO(10) breaking effect may directly contribute
to the source of the hierarchy, i.e., the bulk mass terms. It naturally
explains the difference of the hierarchical patterns between the quark and the
lepton sectors. We also find the possibility of the horizontal unification, in
which three generations of the matter fields are unified to a 3 dimensional
representation of an SU(2) gauge group.


title: Robustness and Predictivity of 4 TeV Unification

abstract:
  The stability of the predictions of two of the standard model parameters,
$\alpha_3(M_Z)$ and $\sin^2 \theta(M_Z)$, in a $M_U \sim 4$ TeV unification
model is examined. It is concluded that varying the unification scale between
$M_U \simeq 2.5$ TeV and $M_U \simeq 5$ TeV leaves robust all predictions
within reasonable bounds. Choosing $M_U = 3.8 \pm 0.4$ TeV gives, at lowest
order, accurate predictions at $M_Z$. The impact of threshold effects on
unification depends on the spectrum of states beyond the standard model.


title: From weak-scale observables to leptogenesis

abstract:
  Thermal leptogenesis is an attractive mechanism for generating the baryon
asymmetry of the Universe. However, in supersymmetric models, the parameter
space is severely restricted by the gravitino bound on the reheat temperature
$T_{RH}$. For hierarchical light neutrino masses, it is shown that thermal
leptogenesis {\it can} work when $T_{RH} \sim 10^{9} $ GeV. The low-energy
observable consequences of this scenario are $ BR(\tau \to \ell \gamma) \sim
10^{-8} - 10^{-9} $. For higher $T_{RH}$, thermal leptogenesis works in a
larger area of parameter space, whose observable consequences are more
ambiguous. A parametrisation of the seesaw in terms of weak-scale inputs is
used, so the results are independent of the texture chosen for the GUT-scale
Yukawa matrices.


title: The Light Gluino Mass Window Revisited

abstract:
  The precise measurements of the ``electroweak observables'' performed at LEP
and SLC are well consistent with the standard model predictions. Deviations
from the standard model arising from vacuum polarization diagrams (also called
``weak loop corrections'') have been constrained in a model-independent manner
with the epsilon formalism. Within the same formalism, additional deviations
from new physics production processes can also be constrained, still in a
model-independent way. For instance, a 95% C.L. limit of Delta Gamma_had} < 3.9
MeV is set on the partial width of any purely hadronic exotic contribution to Z
decays. When applied to the e+e- -> q qbar gluino gluino process, it allows an
absolute lower limit to be set on the gluino mass, m_gluino > 6.3 GeV/c2 at 95%
C.L., which definitely closes the so-called light gluino mass window.


title:
Aspects of the Color Flavor Locking phase of QCD in the Nambu-Jona
  Lasinio approximation

abstract:
  We study two aspects of the CFL phase of QCD in the NJL approximation. The
first one is the issue of the dependence on \mu of the ultraviolet cutoff in
the gap equation, which is solved allowing a running coupling constant. The
second one is the dependence of the gap on the strange quark mass; using the
high density effective theory we perform an expansion in the parameter
(m_s/\mu)^2 after checking that its numerical validity is very good already at
first order.


title: F-term, D-term and hybrid brane inflation

abstract:
  We study inflation and reheating in models for the brane universe,
considering hybrid brane inflation without tachyon condensation. We expect that
some fields that are localized on different branes interact with O(1) coupling
when branes are on top of each other, while the interaction vanishes when
branes are separated at a distance. If the interaction is needed to avoid
spontaneous breaking of supersymmetry on the brane, our idea for hybrid brane
inflation works. In our model, when branes are far apart, supersymmetry is
spontaneously broken by the fields on a brane, which induces inflation. The
inflaton field is the moduli for the brane distance. At the end of inflation,
when branes come close, supersymmetry is restored by the interaction between
fields on the branes, then the oscillation starts to reheat the Universe. In
this paper we construct explicit models for F-term and D-term inflation. There
are at least two major advantages. The most attractive point is that reheating
is natural in our model, because the trigger field is not the tachyon but a
conventional field on the brane. The serious constraint from the loop
correction, which always appears in conventional models for hybrid inflation,
is avoided.


title: Deeply Virtual Compton Scattering and Saturation Approach

abstract:
  We investigate the deeply virtual Compton scattering (DVCS) in the color
dipole approach, implementing the dipole cross section through the saturation
model, which interpolates successfully between soft and hard regimes. The
imaginary and real part of the DVCS amplitude are obtained and the results are
compared to the available data.


title: Dark Energy and Dark Matter

abstract:
  It is a puzzle why the densities of dark matter and dark energy are nearly
equal today when they scale so differently during the expansion of the
universe. This conundrum may be solved if there is a coupling between the two
dark sectors. In this paper we assume that dark matter is made of cold relics
with masses depending exponentially on the scalar field associated to dark
energy. Since the dynamics of the system is dominated by an attractor solution,
the dark matter particle mass is forced to change with time as to ensure that
the ratio between the energy densities of dark matter and dark energy become a
constant at late times and one readily realizes that the present-day dark
matter abundance is not very sensitive to its value when dark matter particles
decouple from the thermal bath. We show that the dependence of the present
abundance of cold dark matter on the parameters of the model differs
drastically from the familiar results where no connection between dark energy
and dark matter is present. In particular, we analyze the case in which the
cold dark matter particle is the lightest supersymmetric particle.


title:
Inclusive D* production in gamma-gamma collisions: including the
  single-resolved contribution with massive quarks

abstract:
  We have calculated the next-to-leading order cross section for the inclusive
production of charm quarks as a function of the transverse momentum p_T and the
rapidity in two approaches using massive or massless charm quarks. For the
single-resolved cross section we have derived the massless limit from the
massive theory. We find that this limit differs from the genuine massless
version with MS-bar factorization by finite corrections. By adjusting
subtraction terms we establish a massive theory with MS-bar subtraction which
approaches the massless theory very fast with increasing transverse momentum.
With these results and including the equivalent results for the direct cross
section obtained previously as well as double-resolved contributions, we
calculate the inclusive D*+- cross section in gamma-gamma collisions using
realistic evolved non-perturbative fragmentation functions and compare with
recent data from the LEP collaborations ALEPH, L3 and OPAL. We find good
agreement.


title:
KamLAND Bounds on Solar Antineutrinos and neutrino transition magnetic
  moments

abstract:
  We investigate the possibility of detecting solar electron antineutrinos with
the KamLAND experiment. These electron antineutrinos are predicted by
spin-flavor oscillations at a significant rate even if this mechanism is not
the leading solution to the SNP. KamLAND is sensitive to antineutrinos
originated from solar ${}^8$B neutrinos. From KamLAND negative results after
145 days of data taking, we obtain model independent limits on the total flux
of solar electron antineutrinos $\Phi({}^8 B)< 1.1-3.5\times 10^4 cm^{-2}\
s^{-1}$, more than one order of magnitude smaller than existing limits, and on
their appearance probability $P<0.15%$ (95% CL). Assuming a concrete model for
antineutrino production by spin-flavor precession, this upper bound implies an
upper limit on the product of the intrinsic neutrino magnetic moment and the
value of the solar magnetic field $\mu B< 2.3\times 10^{-21}$ MeV 95% CL (for
LMA $(\Delta m^2, \tan^2\theta)$ values). Limits on neutrino transition moments
are also obtained. For realistic values of other astrophysical solar parameters
these upper limits would imply that the neutrino magnetic moment is constrained
to be, in the most conservative case, $\mu\lsim 3.9\times 10^{-12} \mu_B$ (95%
CL) for a relatively small field $B= 50$ kG. For higher values of the magnetic
field we obtain: $\mu\lsim 9.0\times 10^{-13} \mu_B$ for field $B= 200$ kG and
$\mu\lsim 2.0\times 10^{-13} \mu_B$ for field $B= 1000$ kG at the same
statistical significance.


title:
Can power corrections be reliably computed in models with extra
  dimensions?

abstract:
  We critically revisit the issue of power-law running in models with extra
dimensions. The analysis is carried out in the context of a higher-dimensional
extension of QED, with the extra dimensions compactified on a torus. It is
shown that a naive $\beta$ function, which simply counts the number of modes,
depends crucially on the way the thresholds of the Kaluza-Klein modes are
crossed. To solve these ambiguities we turn to the vacuum polarization, which,
due to its special unitarity properties, guarantees the physical decoupling of
the heavy modes. This latter quantity, calculated in the context of dimensional
regularization, is used for connecting the low energy gauge coupling with the
coupling of the $D$-dimensional effective field theory. We find that the
resulting relation contains only logarithms of the relevant scales, and no
power corrections. If, instead, hard cutoffs are used to regularize the theory,
one finds power corrections, which could be interpreted as an additional
matching between the effective higher-dimensional model and some unknown, more
complete theory. The possibility of estimating this matching is examined in the
context of a toy model. The general conclusion is that, in the absence of any
additional physical principle, the power corrections depend strongly on the
details of the underlying theory. Possible consequences of this analysis for
gauge coupling unification in theories with extra dimensions are briefly
discussed.


title: The wavelength of neutrino and neutral kaon oscillations

abstract:
  Neutral kaons, and probably also neutrinos, exhibit oscillations between
flavor eigenstates, as a result of being produced in a superposition of mass
eigenstates. Several recent papers have addressed the question of the energies
and momenta of the components of these states, and their effect on the
coherence of the states and on the wavelength of the oscillations. We point out
that the mass eigenstates need have neither equal momentum nor equal energy,
but can nevertheless be coherent, and that a correct treatment of the
kinematics recovers the usual result for the wavelength of the flavor
oscillations.


title: The universal $\ln^{2}s$ increase in total cross sections

abstract:
  While it has long been known that many models of high energy scattering give
cross sections which rise as $\ln^{2}s$, the determination of the coefficient
of this term is rarely given. We show that in gaussian and exponential eikonal
models an exact expression for the cross section can be obtained, which
demonstrates the $\ln^{2}s$ asyptoptic behaviour and determines its
coefficient. The coefficient is universal, as found empirically, and the value
of the constant obtained from the gaussian model is in good agreement with the
empirical value.


title: Top quark and QCD physics at e+e- linear colliders: recent progress

abstract:
  I review the studies, which were reported after the last Linear Collider
Workshop, on top quark physics and QCD physics at a future e+e- linear
collider.


title: Gauge Quintessence

abstract:
  We discuss a new model of quintessence in which the quintessence field is
identified with the extra-component of a gauge field in a compactified
five-dimensional theory. We show that the extremely tiny energy scale $\sim
(3\times 10^{-3} eV)^4$ needed to account for the present acceleration of the
Universe can be naturally explained in terms of high energy scales such as the
scale of Grand Unification.


title:
Optimized Neural Networks to Search for Higgs Boson Production at the
  Tevatron

abstract:
  An optimal choice of proper kinematical variables is one of the main steps in
using neural networks (NN) in high energy physics. Our method of the variable
selection is based on the analysis of a structure of Feynman diagrams
(singularities and spin correlations) contributing to the signal and background
processes. An application of this method to the Higgs boson search at the
Tevatron leads to an improvement in the NN efficiency by a factor of 1.5-2 in
comparison to previous NN studies.


title: Is the a_0(1450) a candidate for the lowest q\bar{q} ^3P_0 state?

abstract:
  For the $a_0(1450)$, considered as the $q\bar{q} 1^3P_0$ state,
"experimental" tensor splitting, $c_{exp}=(-150\pm 40$) MeV, appears to be in
contradiction with conventional theory of fine structure. There is no such
discrepancy if the $a_0(980)$ belongs to the $1^3P_J q\bar{q}$ multiplet. The
hadronic shift of the $a_0(980)$ is shown to be strongly dependent on the value
of the strong coupling in spin-dependent interaction.


title: Resolution of the pion puzzle: the QCD string in Nambu-Goldstone mesons

abstract:
  Pions and kaons have double nature: the chiral dynamics of Nambu-Goldstone
bosons together with the usual string dynamics common to all mesons. To uncover
the interplay of both dynamics the effective chiral Lagrangian is derived from
the QCD Lagrangian using the Field Correlator Method and the pion self-energy
(mass) operator is written explicitly. The latter contains an infinite number
of poles, but normalized to zero at zero momentum because of spontaneous chiral
symmetry breaking. As a result one obtains the Gell-Mann-Oakes-Renner relation
for the ground state pion and (slightly shifted by chiral dynamics) the usual
spectrum of radially excited pions starting with $\pi(1300)$.


title: Factorization breaking in diffractive dijet production

abstract:
  We study diffractive hard dijet production, with one or two rapidity gaps, at
high energies. We emphasize that both hard and Regge factorization are broken
in these processes. We show that a multi-Pomeron-exchange model for screening
effects gives a specific pattern for the breakdown of factorization, which is
in good agreement with diffractive dijet data collected at the Tevatron.


title: The Neutrino Mass Window for Baryogenesis

abstract:
  Interactions of heavy Majorana neutrinos in the thermal phase of the early
universe may be the origin of the cosmological matter-antimatter asymmetry.
This mechanism of baryogenesis implies stringent constraints on light and heavy
Majorana neutrino masses. We derive an improved upper bound on the CP asymmetry
in heavy neutrino decays which, together with the kinetic equations, yields an
upper bound on all light neutrino masses of 0.1 eV. Lepton number changing
processes at temperatures above the temperature T_B of baryogenesis can erase
other, pre-existing contributions to the baryon asymmetry. We find that these
washout processes become very efficient if the effective neutrino mass
\tilde{m}_1 is larger than m_* \simeq 10^{-3} eV. All memory of the initial
conditions is then erased. Hence, for neutrino masses in the range from (\Delta
m^2_sol)^{1/2} \simeq 8*10^{-3} eV to (\Delta m^2_atm)^{1/2} \simeq 5*10^{-2}
eV, which is suggested by neutrino oscillations, leptogenesis emerges as the
unique source of the cosmological matter-antimatter asymmetry.


title: Present and Future Bounds on Non-Standard Neutrino Interactions

abstract:
  We consider Non-Standard neutrino Interactions (NSI), described by
four-fermion operators of the form $(\bar{\nu}_{\alpha} \gamma {\nu}_{\beta})
(\bar{f} \gamma f)$, where $f$ is an electron or first generation quark. We
assume these operators are generated at dimension $\geq 8$, so the related
vertices involving charged leptons, obtained by an SU(2) transformation
$\nu_{\delta} \to e_{\delta}$, do not appear at tree level. These related
vertices necessarily arise at one loop, via $W$ exchange. We catalogue current
constraints from $\sin^2 \theta_W$ measurements in neutrino scattering, from
atmospheric neutrino observations, from LEP, and from bounds on the related
charged lepton operators. We estimate future bounds from comparing KamLAND and
solar neutrino data, and from measuring $\sin^2 \theta_W$ at the near detector
of a neutrino factory. Operators constructed with $\nu_\mu$ and $\nu_e$ should
not confuse the determination of oscillation parameters at a $\nu$factory,
because the processes we consider are more sensitive than oscillations at the
far detector. For operators involving $\nu_\tau$, we estimate similar
sensitivities at the near and far detector.


title: New Physics Contributions to The B -> phi K_S Decay

abstract:
  Recent measurements of the time-dependent CP asymmetry of the B -> phi K_S
decay give results whose central values differ from standard model
expectations. It is shown how such data can be used to identify new physics
contributions in a model-independent manner. In general, a sizeable new
amplitude with nontrivial weak and strong phases would be required to explain
current data. Improvement in the quality of data will allow one to form a more
definite conclusion.


title:
Color Octet Contribution to High p_T J/\Psi Production in pp Collisions
  at \sqrt s = 500 and 200 GeV at RHIC

abstract:
  We compute \frac{d\sigma}{dp_T} of the J/\psi production in pp collisions at
RHIC at \sqrt s = 500 and 200 GeV by using both the color octet and singlet
models in the framework of non-relativistic QCD. The J/\psi we compute here
includes the direct J/\psi from the partonic fusion processes and the J/\psi
coming from the radiative decays of \chi_J's both in the color octet and
singlet channel. The high p_T J/\psi production cross section is computed
within the PHENIX detector acceptance ranges: -0.35 < \eta < 0.35 and 1.2 <
\|\eta| < 2.4, the central electron and forward muon arms. It is found that the
color octet contribution to J/\psi production is dominant at RHIC energy in
comparison to the color singlet contributions. We compare our results with the
recent preliminary data obtained by PHENIX detector for the high p_T J/\psi
measurements. While the color singlet model fails to explain the data
completely the color octet model is in agreement with the single data point
above 2 GeV transverse momentum. A measurement of J/\psi production at RHIC in
the next run with better statistics will allow us to determine the validity of
the color octet model of J/\psi production at RHIC energies. This is very
important because it is necessary to know the exact mechanism for J/\psi
production in pp collisions at RHIC if one is to make predictions of J/\psi
suppression as a signature of quark-gluon plasma. These mechanisms also play an
important role in determining the polarized spin structure function of the
proton at RHIC.


title: The pair production of charmed mesons in the photon-photon interaction

abstract:
  In the framework of the constituent quark model the exclusive pair production
of the charmed mesons in the photon-photon interaction is calculated. The
comparison of these predictions with the ones of the heavy quark effective
theory is performed. It is shown, that the light valence quark of D-meson plays
the essential role not only in the hadronization process, but also in the
production of the heavy c-quark. Moreover, it is shown, that because of the
strong interaction between the initial photon field and the light quark charge
the similar situation is kept even in the limit (m_{Q}\to \infty), whence it is
concluded, that the application of the heavy quark effective theory in the case
of the photon-photon interaction is not valid because it does not take into
account one of the dominant mechanisms of the heavy meson production.


title: Hierarchy and Up-Down Parallelism of Quark Mass Matrices

abstract:
  In view of the quark mass hierarchy and in the assumption of the up-down
parallelism, we derive two phenomenologically-favored patterns of Hermitian
quark mass matrices from the quark flavor mixing matrix. We compare one of them
with two existing {\it Ans$\it\ddot{a}$tze} proposed by Rosner and Worah and by
Roberts {\it et al}, and find that only the latter is consistent with the
present experimental data.


title: On the thermal sunset diagram for scalar field theories

abstract:
  We study the so-called `` sunset diagram'', which is one of two-loop
self-energy diagrams, for scalar field theories at finite temperature.
  For this purpose, we first find the complete expression of the bubble
diagram, the one-loop subdiagram of the sunset diagram, for arbitrary momentum.
  We calculate the temperature independent part and dependent part of the
sunset diagram separately. For the former, we obtain the discontinuous part
first and the finite continuous part next using a twice-subtracted dispersion
relation. For the latter, we express it as a one-dimensional integral in terms
of the bubble diagram.
  We also study the structure of the discontinuous part of the sunset diagram.
Physical processes, which are responsible for it, are identified. Processes due
to the scattering with particles in the heat bath exist only at finite
temperature and generate discontinuity for arbitrary momentum, which is a
remarkable feature of the two-loop diagrams at finite temperature.
  As an application of our result, we study the effect of the diagram on the
spectral function of the sigma meson at finite temperature in the linear sigma
model, which was obtained at one-loop order previously. At high temperature
where the decay $\sigma\to\pi\pi$ is forbidden, sigma acquires a finite width
of the order of $10 {\rm MeV}$ while within the one-loop calculation its width
vanishes. At low temperature, the spectrum does not deviate much from that at
one-loop order. Possible consequences with including other two-loop diagrams
are discussed.


title: Jet Vertex in the Next-to-Leading log(s) Approximation

abstract:
  The next-to-leading corrections to the jet vertex which is relevant for the
Mueller-Navelet jets production in hadronic collisions and for the forward jet
cross section in lepton-hadron collisions are presented in the context of a k_t
factorizazion formula which resums the leading and next-to-leading logarithms
of the energy.


title:
Reply to comment on ``A simple explanation of the non-appearance of
  physical gluons and quarks"

abstract:
  This is the reply to a comment by Andreas Aste [hep-th/0302103] on a previous
article of mine in Can.J.Phys. The counter-arguments used by Aste utilize a
mathematical limit without physical meaning. We still contend that in QCD, the
particles ``gluons'' and ``quarks'' are merely artifacts of an approximation
method (the perturbative expansion) and are simply absent in the exact theory.


title:
The constraints on the non-singlet polarised parton densities from the
  infrared-renormalon model

abstract:
  Using the infrared-renormalon approach, we obtain the constraints on the
next-to-leading order non-singlet polarised parton densities. The advocated
feature follows from the consideration of the effect revealed in the process of
the next-to-leading order fits to the data for the assymetry of polarised
lepton-nucleon scattering which result in the approximate nullification of the
$1/Q^2$-correction to A_1^N(x,Q^2).


title:
Theoretical uncertainties in sparticle mass predictions from
  computational tools

abstract:
  We estimate the current theoretical uncertainty in sparticle mass predictions
by comparing several state-of-the-art computations within the minimal
supersymmetric standard model (MSSM). We find that the theoretical uncertainty
is comparable to the expected statistical errors from the Large Hadron Collider
(LHC), and significantly larger than those expected from a future e+e- Linear
Collider (LC). We quantify the theoretical uncertainty on relevant sparticle
observables for both LHC and LC, and show that the value of the error is
significantly dependent upon the supersymmetry (SUSY) breaking parameters. We
also present the theoretical uncertainty induced in fundamental-scale SUSY
breaking parameters when they are fitted from LHC measurements. Two regions of
the SUSY parameter space where accurate predictions are particularly difficult
are examined in detail: the large tan(beta) and focus point regimes.


title:
Hidden Local Symmetry at Loop -- A New Perspective of Composite Gauge
  Boson and Chiral Phase Transition --

abstract:
  We develop an effective field theory of QCD and QCD-like theories, based on
the hidden local symmetry (HLS) model. We formulate the chiral perturbation
theory with loops of rho as well as pi and further include quadratic
divergences which are crucial to the chiral phase transition. Detailed
calculations of the one-loop renormalization-group equation of the parameters
of the HLS model are given, with the bare parameters (defined at cutoff Lambda)
determined by the matching (``Wilsonian matching'') with the underlying QCD at
Lambda through the operator-product expansion of current correlators. The
Wilsonian matching predicts low energy phenomenology for the three-flavored QCD
in remarkable agreement with the experiments. When the chiral symmetry
restoration takes place in the underlying QCD, the HLS model uniquely leads to
the Vector Manifestation (VM) as a new pattern of Wigner realization of chiral
symmetry, with the rho becoming degenerate with the massless pi as the chiral
partner. The VM is in fact realized in the large Nf QCD when Nf to Nf^{crit}-0,
with Nf^{crit} = 5 Nc/3 being in rough agreement with the lattice simulation
for Nc=3. The VM can be realized also in hot and/or dense QCD.


title:
The q_T spectrum of the Higgs boson at the LHC in QCD perturbation
  theory

abstract:
  We consider the transverse-momentum (q_T) distribution of Higgs bosons
produced at hadron colliders. We use a formalism that uniformly treats both the
small-q_T and large-q_T regions in QCD perturbation theory. At small q_T (q_T
<< M_H, M_H being the mass of the Higgs boson), we implement an all-order
resummation of logarithmically-enhanced contributions up to
next-to-next-to-leading logarithmic accuracy. At large q_T (q_T \gtap M_H), we
use fixed-order perturbation theory up to next-to-leading order. The resummed
and fixed-order approaches are consistently matched by avoiding double-counting
in the intermediate-q_T region. In this region, the introduction of unjustified
higher-order terms is avoided by imposing unitarity constraints, so that the
integral of the q_T spectrum exactly reproduces the perturbative result for the
total cross section up to next-to-next-to-leading order. Numerical results at
the LHC are presented. These show that the main features of the q_T
distribution are quite stable with respect to perturbative QCD uncertainties.


title:
Comparison of Temperature-Dependent Hadronic Current Correlation
  Functions Calculated in Lattice Simulations of QCD and with a Chiral
  Lagrangian Model

abstract:
  The Euclidean-time hadronic current correlation functions, $G_P(\tau, T)$ and
$G_V(\tau, T)$, of pseudoscalar and vector currents have recently been
calculated in lattice simulations of QCD and have been used to obtain the
corresponding spectral functions. We have used the Nambu-Jona-Lasinio (NJL)
model to calculate such spectral functions, as well as the Euclidean-time
correlators, and have made a comparison to the lattice results for the
correlators. We find evidence for the type of temperature dependence of the NJL
coupling parameters that we have used in previous studies of the mesonic
confinement-deconfinement transition. We also see that the spectral functions
obtained when using the maximum-entropy-method (MEM) and the lattice data
differ from the spectral functions that we calculate in our chiral model.
However, our results for the Euclidean-time correlators are in general
agreement with the lattice results, with better agreement when our
temperature-dependent coupling parameters are used than when
temperature-independent parameters are used for the NJL model. We also discuss
some additional evidence for the utility of temperature-dependent coupling
parameters for the NJL model. For example, if the constituent quark mass at T=0
is $352 {MeV}$ in the chiral limit, the transition temperature is $T_c=208
{MeV}$ for the NJL model with a standard momentum cutoff parameter. (If a
Gaussian momentum cutoff is used, we find $T_c=225 {MeV}$ in the chiral limit,
with $m=368 {MeV}$ at T=0.) The introduction of a weak temperature dependence
for the coupling constant will move the value of $T_c$ into the range 150-170
MeV, which is more in accord with what is found in lattice simulations of QCD
with dynamical quarks.


title: Pinning down the kaon form factors in K^+ -> mu^+ nu_mu gamma decay

abstract:
  We find that the normal muon polarization in the decay K->mu nu_mu gamma is
very sensitive to the values of the kaon vector F_V and axial-vector F_A form
factors. It is shown that the ongoing KEK-E246 experiment can definitely
determine the signs of the sum of the form factors if their difference is fixed
from other considerations. This method can also verify the form factor values
and signs obtained from the K^+ -> l^+ nu_l e^+ e^- decays. A new experiment
with sensitivity to the normal and transverse muon polarizations of about 10^-4
will provide a unique possibility to determine the F_V and F_A values with a
few percent accuracy.


title:
Non-decoupling effects of SUSY in the physics of Higgs bosons and their
  phenomenological implications

abstract:
  We consider a plausible scenario in the Minimal Supersymmetric Standard Model
(MSSM) where all the genuine supersymmetric (SUSY) particles are heavier than
the electroweak scale. In this situation, indirect searches via their radiative
corrections to low energy observables are complementary to direct searches, and
they can be crucial if the SUSY masses are at the TeV energy range. We
summarize the most relevant heavy SUSY radiative effects in Higgs boson physics
and emphasize those that manifest a non-decoupling behaviour. We focus, in
particular, on the SUSY-QCD non-decoupling effects in fermionic Higgs decays,
flavour changing Higgs decays and Yukawa couplings. Some of their
phenomenological implications at future colliders are also studied.


title: Minimal Length Uncertainty Relation and the Hydrogen Spectrum

abstract:
  Modifications of Heisenberg's uncertainty relations have been proposed in the
literature which imply a minimum position uncertainty. We study the low energy
effects of the new physics responsible for this by examining the consequent
change in the quantum mechanical commutation relations involving position and
momenta. In particular, the modifications to the spectrum of the hydrogen atom
can be naturally interpreted as a varying (with energy) fine structure
constant. From the data on the energy levels we attempt to constrain the scale
of the new physics and find that it must be close to or larger than the weak
scale. Experiments in the near future are expected to change this bound by at
least an additional order of magnitude.


title: $\Xi^-$ and $\Omega$ Distributions in Hadron-Nucleus Interactions

abstract:
  Strange baryons have long been known to exhibit a leading particle effect. A
recent comparison of $\Xi^-$ production in $\pi^-$, $n$, and $\Sigma^-$
interactions with nuclei show this effect clearly. These data are supplemented
by earlier measurements of $\Xi^-$ and $\Omega$ production by a $\Xi^-$ beam.
We calculate the $\Xi^-$ and $\Omega$ $x_F$ distributions and nuclear
dependence in $hA$ interactions using the intrinsic model.


title: Final-State Phases in $B \to$ Baryon-Antibaryon Decays

abstract:
  The recent observation of the decay $\ob \to \Lambda_c^+ \bar p$ suggests
that related decays may soon be visible at $e^+ e^-$ colliders. It is shown how
these decays can shed light on strong final-state phases and amplitudes
involving the spectator quark, both of which are normally expected to be small
in B decays.


title:
Can the Two-Higgs-Doublet Model Survive the Constraint from the Muon
  Anomalous Magnetic Moment as Suggested?

abstract:
  Requiring the two-Higgs-doublet model II to accommodate the 3$\sigma$
deviation in the muon anomalous magnetic moment imposes specific constraints on
the Higgs spectrum. We analyze the combination of all the relevant, available,
constraints on the model parameter space. The use of constraints from $b\to s
\gamma$, the precision electroweak measurements of $R_b$, and the $\rho$
parameter, together with exclusions from direct searches at LEP, give extremely
severe restrictions on the model parameters. That is "almost enough" to kill
the model altogether. The exclusion would be even stronger if the direct
searches can be optimized to complement the other constraints, as will be
discussed in details in this work.


title: From QCD Instantons at HERA to Electroweak B+L Violation at VLHC

abstract:
  This review emphasizes the close analogy between hard QCD instanton-induced
chirality violating processes in deep-inelastic scattering and electroweak
instanton-induced baryon plus lepton number (B+L) violating processes in
Quantum Flavor Dynamics (QFD). Recent information about QCD instantons, both
from lattice simulations and from the H1 experiment at HERA, can be used to
learn about the fate of electroweak B+L violation at future high energy
colliders in the hundreds of TeV regime, such as the projected Very Large
Hadron Collider (VLHC). The cross-sections turn out to be unobservably small in
a conservative fiducial kinematical region inferred from the above mentioned
QCD-QFD analogy. An extrapolation - still compatible with lattice results and
HERA - beyond this conservative limit indicates possible observability at VLHC.


title: Determination of the Higgs boson spin with a linear e+e- collider

abstract:
  The energy dependence of the production cross section of a light Higgs boson
is studied at threshold and compared to the expectations of several spin
assumptions. Cross section measurements at three centre-of-mass energies with
an integrated luminosity of 20 fb-1 allow the confirmation of the scalar nature
of the Higgs Boson.


title:
Dual coherent particle emission as generalized two-component
  Cherenkov-like effect

abstract:
  In this Letter we introduce a new kind of coherent particle production
mechanism called dual coherent particle emission (DCPE) as generalized
two-component Cherenkov-like effect, which takes place when the phase velocity
of emitted particle v_{Mph} and the particle source phase velocity v_{B_1ph}
satisfy a specific DCPE condition: v_{Mph} <= v_{B_1ph}^{-1}. The general
signatures of the DCPE in dielectric, nuclear and hadronic media are
established and some experimental evidences are presented.


title: Resummation in hot field theories

abstract:
  We consider a scalar theory at finite temperature in the 2PI resummation
scheme, including phi^3 and phi^4 interactions. Already at the one loop level
in this scheme, we have to deal with a non local approximation. We carry out
the renormalization and obtain finite equations for the propagator. Within this
model we can explore the effect of non local contributions to the self-energy
in the evaluation of thermodynamic quantities.


title: Cosmology with varying scales and couplings

abstract:
  The time variation of fundamental mass scales can have profound cosmological
implications. We investigate a particular model of crossover quintessence which
is compatible with all present cosmological observations. This model can also
reconcile the reported time variation of the fine structure constant from
quasar absorption lines with the bounds from archeo-nuclear physics and tests
of the equivalence principle.


title:
Renormalization of relativistic baryon chiral perturbation theory and
  power counting

abstract:
  We discuss a renormalization scheme for relativistic baryon chiral
perturbation theory which provides a simple and consistent power counting for
renormalized diagrams. The method involves finite subtractions of dimensionally
regularized diagrams beyond the standard $\bar{\rm MS}$ scheme of chiral
perturbation theory to remove contributions violating the power counting. This
is achieved by a suitable renormalization of the parameters of the most general
effective Lagrangian. In addition to simplicity our method has the benefit that
it can be easily applied to multiloop diagrams. As an application we discuss
the mass and the scalar form factor of the nucleon and compare the results with
the expressions of the infrared regularization of Becher and Leutwyler.


title: Natural relations among physical observables in the neutrino mass matrix

abstract:
  We find all possible relations among physical observables arising from
neutrino mass matrices that describe in a natural way the currently observed
pattern (tan_23 and tan_12 large, dm^2_Sun/dm^2_Atm and tan_13 small) in terms
of a minimum number of parameters. Natural here means due only to the relative
smallness (vanishing) of some parameters in the relevant lagrangian, without
special relations or accidental cancellations among them.


title:
Anomalously light mesons in a (1+1)-dimensional supersymmetric theory
  with fundamental matter

abstract:
  We consider N=1 supersymmetric Yang-Mills theory with fundamental matter in
the large-N_c approximation in 1+1 dimensions. We add a Chern-Simons term to
give the adjoint partons a mass and solve for the meson bound states. Here
mesons are color-singlet states with two partons in the fundamental
representation but are not necessarily bosons. We find that this theory has
anomalously light meson bound states at intermediate and strong coupling. We
also examine the structure functions for these states and find that they prefer
to have as many partons as possible at low longitudinal momentum fraction.


title:
Higgs Pair-Production in the Standard Model at Next Generation Linear
  $e^+e^-$ Colliders

abstract:
  We study the Higgs pair-production in the Standard Model of the strong and
electroweak interactions at future $e^{+}e^{-}$ collider energies, with the
reaction $e^{+}e^{-}\to t \bar t HH$. We evaluated the total cross section of
$t\bar tHH$ and calculate the number total of events considering the complete
set of Feynman diagrams at tree-level. The numerical computation is done for
the energy which is expected to be available at a possible Next Linear
$e^{+}e^{-}$ Collider: with center-of-mass energy $800, 1600$ $GeV$ and
luminosity 1000 $fb^{-1}$.


title: Phenomenological studies in QCD resummation

abstract:
  We study applications of QCD soft-gluon resummations to electroweak
annihilation cross sections. We focus on a formalism that allows to resum
logarithmic corrections arising near partonic threshold and at small transverse
momentum simultaneously.


title:
Prospects for detection of $\Upsilon(1D) \to \Upsilon(1S) \pi \pi$ via
  $\Upsilon(3S) \to \Upsilon(1D) + X$

abstract:
  At least one state in the first family of D-wave $b \bar b$ quarkonium levels
has been discovered near the predicted mass of 10.16 GeV/$c^2$. This state is
probably the one with J=2. This state and the ones with J=1 and J=3 may
contribute a detectable amount to the decay $\Upsilon(1D) \to \Upsilon(1S) \pi
\pi$, depending on the partial widths for these decays for which predictions
vary considerably. The prospects for detection of the chain $\Upsilon(3S) \to
\Upsilon(1D) + X \to \Upsilon \pi \pi + X$ are discussed.


title:
Simultaneous solution to B --> phi K CP Asymmetry and B --> eta(prime)
  K, eta K^* branching ratio anomalies from R-parity violation

abstract:
  The branching ratios for the neutral and charged B decay channels to $\eta'
K$ and $\eta K^*$ are well above the Standard Model expectations. Moreover, the
mixing-induced CP asymmetry in $B \to \phi K_S$ is incompatible to that found
in $B\to J/\psi K_S$. We investigate whether a flavour-specific tree-level
$b\to s \bar{s} s$ operator coming from R-parity violating supersymmetry can
resolve both these discrepancies, without jeopardizing those results which are
in agreement with the Standard Model. We found that it is possible to have a
parameter space satisfying all these requirements, including that of a low
strong phase difference compatible with the color transparency argument.
Furthermore, we put a robust bound on the relevant coupling, which is two
orders of magnitude better than the existing one.


title: Strong Two--Body Decays of Light Mesons

abstract:
  In this paper, we present results on strong two-body decay widths of light
$q\bar q$ mesons calculated in a covariant quark model. The model is based on
the Bethe-Salpeter equation in its instantaneous approximation and has already
been used for computing the complete meson mass spectrum and many electroweak
decay observables. Our approach relies on the use of a phenomenological
confinement potential with an appropriate spinorial Dirac structure and 't
Hooft's instanton--induced interaction as a residual force for pseudoscalar and
scalar mesons. The transition matrix element for the decay of one initial meson
into two final mesons is evaluated in lowest order by considering conventional
decays via quark loops as well as Zweig rule violating instanton--induced
decays generated by the six--quark vertex of 't Hooft's interaction; the latter
mechanism only contributes if all mesons in the decay have zero total angular
momentum. We show that the interference of both decay mechanisms plays an
important role in the description of the partial widths of scalar and
pseudoscalar mesons.


title: About self energy in 3-dimensional electrodynamics

abstract:
  The fermion electromagnetic mass has been evaluated in 3-dimensional
electrodynamics in the first nonvanishing order of N^-1 approximation (N is the
number of the fermions in the model). It is established, that, if one proceeds
from the self energy integral in QED3, in the approximation under consideration
for the mentioned above mass one can obtain the quantum result for the fermion
electromagnetic mass as well the classical one. The electromagnetic mass of the
particle has the quantum origin, if its Compton wavelength satisfies the
condition lambda_c >> alfa (alfa is the scale parameters of the model which are
the "elementary length" r_0 and 8/alfa, alfa_0^2*N, alfa_0^2 is the dimensional
coupling constant in QED3); the particle electromagnetic mass has the classical
origin, if lambda_c<<alfa. The obtained results are discussed.


title: Optical activity of neutrinos and antineutrinos

abstract:
  Using the one-loop helicity amplitudes for low-energy $\nu\gamma\to\nu\gamma$
and $\bar\nu\gamma\to\bar\nu\gamma$ scattering in the standard model with
massless neutrinos, we study the optical activity of a sea of neutrinos and
antineutrinos. In particular, we estimate the values of the index of refraction
and rotary power of this medium in the absence of dispersion.


title:
Three-Loop Radiative-Recoil Corrections to Hyperfine Splitting in
  Muonium

abstract:
  We calculate three-loop radiative-recoil corrections to hyperfine splitting
in muonium generated by the diagrams with the first order electron and muon
polarization loop insertions in graphs with two exchanged photons. These
corrections are enhanced by the large logarithm of the electron-muon mass
ratio. The leading logarithm squared contribution was obtained a long time ago.
Here we calculate the single-logarithmic and nonlogarithmic contributions. We
previously calculated the three-loop radiative-recoil corrections generated by
two-loop polarization insertions in the exchanged photons. The current paper
therefore concludes calculation of all three-loop radiative-recoil corrections
to hyperfine splitting in muonium generated by diagrams with closed fermion
loop insertions in the exchanged photons. The new results obtained here improve
the theory of hyperfine splitting, and affect the value of the electron-muon
mass ratio extracted from experimental data on the muonium hyperfine splitting.


title: A New Approach for Analytic Amplitude Calculations

abstract:
  We present a method for symbolic calculation of Feynman amplitudes for
processes involving both massless and massive fermions. With this approach
fermion strings in a specific amplitude can be easily evaluated and expressed
as basic Lorentz scalars. The new approach renders the symbolic calculation of
some complicated physical processes more feasible and easier, especially with
the assistance of algebra manipulating codes for computer.


title: Scalar sigma meson effects in radiative rho^0-meson decays

abstract:
  We study the radiative $\rho^0\to \pi^+\pi^-\gamma$ and $\rho^0\to
\pi^0\pi^0\gamma$ decays and we calculate their branching ratios using a
phenomenological approach by adding to the amplitude calculated within the
framework of chiral perturbation theory and vector meson dominance the
amplitude of $\sigma$-meson intermediate state. Our results for the branching
ratios are in good agreement with the experimental values.


title: Bose-Einstein and Fermi-Dirac Interferometry in Particle Physics

abstract:
  The application of the Bose-Einstein and Fermi-Dirac interferometry to
multi-hadron final states of particle reactions is reviewed. The underlying
theoretical concepts of particle interferometry is presented where a special
emphasis is given to the recently proposed Fermi-Dirac correlation analysis.
The experimental tools used for the interferometry analyses and the
interpretation of their results are discussed in some details. In particular
the interpretation of the dimension $r$, as measured from the interferometry
analysis, is investigated and compared to that measured in heavy-ion
collisions. Finally the similarity between the dependence of $r$ on the hadron
mass and the interatomic separation on the atomic mass in Bose condensates is
outlined.


title: WMAPping out Neutrino Masses

abstract:
  Recent data from from the Wilkinson Microwave Anisotropy Probe (WMAP) place
important bounds on the neutrino sector. The precise determination of the
baryon number in the universe puts a strong constraint on the number of
relativistic species during Big-Bang Nucleosynthesis. WMAP data, when combined
with the 2dF Galaxy Redshift Survey (2dFGRS), also directly constrain the
absolute mass scale of neutrinos. These results impinge upon a neutrino
oscillation interpretation of the result from the Liquid Scintillator Neutrino
Detector (LSND). We also note that the Heidelberg--Moscow evidence for
neutrinoless double beta decay is only consistent with the WMAP+2dFGRS data for
the largest values of the nuclear matrix element.


title: 2-loop QCD corrections to Bc-meson leptonic constant

abstract:
  We present results for two-loop QCD corrections to the short distance
coefficient that governs leptonic decay of Bc-meson. After brief discussion of
the technics of asymptotic threshold expansion used to perform this
calculation, we give comments on the numerical value of two-loop corrections
and its impact on NRQCD description of Bc-meson bound state dynamics.


title: Isosinglet Scalar Mesons Below 2 GeV and the Scalar Glueball Mass

abstract:
  A collective treatment of the I=0 scalar mesons below 2 GeV [sigma (550),
f0(980), f0(1370), f0(1500) and f0(1710)] in a non-linear chiral Lagrangian
framework that is constrained by the mass and the partial decay widths of the
I=1/2,1 scalars [kappa(900), K0*(1430), a0(980) and a0(1450)] is presented. The
sub-structure of these states in terms of two and four quark components, as
well as a glueball component is explored, and its correlation with the mass of
f0(1370) is studied. Consistency with the available experimental data suggests
that the sigma(550) is dominantly a non-strange four-quark state, whereas the
sub-structure of other I=0 states are sensitive to the input mass of f0(1370).
This investigation estimates the scalar glueball mass in the range 1.47--1.64
GeV.


title:
About Classical Aspect of the Chiral Symmetry Dynamical Breaking in
  Three-Dimensional Electrodynamics

abstract:
  Attention is paid to the fact that the stress tensor diagonal components of
the point charged particle field in three-dimensional electrodynamics are equal
to zero. It allows to suppose the particle mass origin is field in the model,
if one loop correction to the classical potential of this field is taken into
account. In the noticed approach static potential and field strength are
evaluated and the electrical radius of the particle is found. It turns out that
this radius is connected with the vacuum polarization and with the particle
electrical field screening at the large distances.


title:
NNLO corrections to the total cross section for Higgs boson production
  in hadron-hadron collisions

abstract:
  We present the next-to-next-to-leading order (NNLO) corrections to the total
cross section for (pseudo-) scalar Higgs boson production using an alternative
method than those used in previous calculations. All QCD partonic subprocesses
have been included and the computation is carried out in the effective
Lagrangian approach which emerges from the standard model by taking the limit
$m_t \to \infty$ where $m_t$ denotes the mass of the top quark. Our results
agree with those published earlier in the literature. We estimate the
theoretical uncertainties by comparing the $K$-factors and the variation with
respect to the mass factorization/renormalization scales with the results
obtained by lower order calculations. We also investigate the dependence of the
cross section on several parton density sets provided by different groups.
Further we study which part of the coefficient functions dominates the cross
section. This is of interest for the resummation of large corrections which
occur near the boundary of phase space. It turns out that depending on the
definition of the total cross section the latter is dominated by the the
soft-plus-virtual gluon corrections represented by $\delta(1-x)$ and
$(\ln^i(1-x)/(1-x))_+$ terms. PACS numbers: 12.38.-t, 12.38.Bx, 13.85.-t,
14.80.Gt.


title:
Effect of the relativistic spin rotation on two--particle spin
  composition

abstract:
  The effect of the relativistic spin rotation on two--particle spin states,
conditioned by the setting of the spins of the particles in their rest frames
and by the noncommutativity of the Lorentz transformations along noncolinear
directions, is discussed. Particularly, the transition from the c.m.s. of two
spin-1/2 particles to the laboratory is considered. When the vectors of the
c.m.s. particle velocities are not colinear with the velocity vector of the
c.m.s., the angles of the relativistic spin rotation for the two particles are
different. As a result, the relative fractions of the singlet and triplet
states in the relativistic system of two spin-1/2 particles depend on the
concrete frame in which the two-particle system is analyzed.


title:
D^+_s -> pi^+ pi^+ pi^- decay: the 1^3P_0 s anti-s component in
  scalar-isoscalar mesons

abstract:
  On the basis of data on the decay D^+_s -> pi^+ pi^+ pi^-, which goes
dominantly via the transition D_s -> pi^+ s anti-s, we evaluate the 1^3P_0 s
anti-s components in the scalar-isoscalar resonances f0(980), f0(1300),
f0(1500) and broad state f0(1200-1600)$. The data point to a large s anti-s
component in the f0(980): 40% < s anti-s < 70%. Nearly 30% of the 1^3P_0 s
anti-s component flows to the mass region 1300-1500 MeV being shared by
f0(1300), f0(1500) and broad state f0(1200-1600): the interference of these
states results in a peak near 1400 MeV with the width around 200 MeV.


title: An Estimate of the Percolation Parameter in Heavy Ion Collisions

abstract:
  From existing hadron and heavy ion collisions data on \bar{p}/p central
production we estimate the value of the percolation parameter at RHIC energies.


title: Multiparticle correlations from momentum conservation

abstract:
  Using a generating-function formalism, we compute the contribution of
momentum conservation to multiparticle correlations between the emitted
particles in high-energy collisions. In particular, we derive a compact
expression of the genuine M-particle correlation, for arbitrary M.


title:
Prompt neutrinos from atmospheric c-cbar and b-bbar production and the
  gluon at very small x

abstract:
  We improve the accuracy of the extrapolation of the gluon distribution of the
proton to very small x, and show that the charm production cross section,
needed to calculate the cosmic ray-induced `atmospheric' flux of ultrahigh
energy prompt muon and tau neutrinos, may be predicted within perturbative QCD
to within about a factor of three. We follow the sequence of interactions and
decays in order to calculate the neutrino fluxes as a function of energy up to
10^9 GeV. We also compute the prompt neutrino tau flux from b-bbar production,
hadronization and decay. New cosmic sources of neutrinos will be indicated if
more prompt neutrinos are observed than predicted. If fewer neutrinos are
observed than predicted, then constraints will be imposed on the nuclear
composition of cosmic rays. The advantages of studying tau neutrinos are
emphasized. We provide a simple parameterization of the prediction for the
inclusive cross section for c quark production in high energy proton--air
collisions.


title: ZZH coupling : A probe to the origin of EWSB ?

abstract:
  We argue that the $ZZH$ coupling constitutes a simple probe of the nature of
the scalar sector responsible for electroweak symmetry breaking. We demonstrate
the efficacy of this measure through an analysis of four-dimensional models
containing scalars in arbitrary representation of $SU(2) \times U(1)$, as well
as extra-dimensional models with a non-factorizable geometry. A possible role
for the $t \bar t H$ couplings is also discussed.