title: A Schematic Model of Leptons and Quarks Based on Majorana Partners

abstract:
  The possible extension of generation structure is investigated on the basis
of a composite model, in which leptons and quarks are composed of rishons $T$
with charge 1/3 and purely neutral $V$. In this sub-system, we regard $V$ as
the origin of Majorana particles. The seesaw mechanism implies the possible
existence of heavy $V$, denoted as $V_B$ in addition to ordinary $V$, denoted
as $V_s$. If we regard $V_B$ as a constitute block of leptons and quarks, a new
generation scheme arises. This new scheme satisfies the anomaly-free condition.


title: Top Decay and Bottom Fragmentation in NLO QCD

abstract:
  We apply the method of perturbative fragmentation to study bottom
fragmentation in top decay. We present the energy spectrum of b-quarks and
b-flavoured hadrons in top decay


title: Ubiquitous CP violation in a top-inspired left-right model

abstract:
  We explore CP violation in a Left-Right Model that reproduces the quark mass
and CKM rotation angle hierarchies in a relatively natural way by fixing the
bidoublet Higgs VEVs to be in the ratio m_b:m_t. Our model is quite general and
allows for CP to be broken by both the Higgs VEVs and the Yukawa couplings.
Despite this generality, CP violation may be parameterized in terms of two
basic phases. A very interesting feature of the model is that the mixing angles
in the right-handed sector are found to be equal to their left-handed
counterparts to a very good approximation. Furthermore, the right-handed
analogue of the usual CKM phase delta_L is found to satisfy the relation
delta_R \approx delta_L. The parameter space of the model is explored by using
an adaptive Monte Carlo algorithm and the allowed regions in parameter space
are determined by enforcing experimental constraints from the K and B systems.
This method of solution allows us to evaluate the left- and right-handed CKM
matrices numerically for various combinations of the two fundamental CP-odd
phases in the model. We find that all experimental constraints may be satisfied
with right-handed W and Flavour Changing Neutral Higgs masses as low as about 2
TeV and 7 TeV, respectively.


title: TeV-Scale Z' Bosons from D-branes

abstract:
  Generic D-brane string models of particle physics predict the existence of
extra U(1) gauge symmetries beyond hypercharge. These symmetries are not of the
E_6 class but rather include the gauging of Baryon and Lepton numbers as well
as certain Peccei-Quinn-like symmetries. Some of the U(1)'s have triangle
anomalies, but they are cancelled by a Green-Schwarz mechanism. The
corresponding gauge bosons typically acquire a mass of order the string scale
M_S by combining with two-index antisymmetric fields coming from the closed
string sector of the theory. We argue that in string models with a low string
scale M_S proportional to 1-10 TeV, the presence of these generic U(1)'s may be
amenable to experimental test. Present constraints from electroweak precision
data already set important bounds on the mass of these extra gauge bosons. In
particular, for large classes of models, rho-parameter constraints imply M_S >=
1.5 TeV. In the present scheme some fraction of the experimentally measured Z^0
mass would be due not to the Higgs mechanism, but rather to the mixing with
these closed string fields. We give explicit formulae for recently constructed
classes of intersecting D6- and D5-brane models yielding the Standard Model
(SM) fermion spectrum.


title:
New constraint from Electric Dipole Moments on chargino baryogenesis in
  MSSM

abstract:
  A commonly accepted mechanism of generating baryon asymmetry in the minimal
supersymmetric standard model (MSSM) depends on the CP violating relative phase
between the gaugino mass and the Higgsino mu term. The direct constraint on
this phase comes from the limit of electric dipole moments (EDM) of various
light fermions. To avoid such a constraint, a scheme which assumes the first
two generation sfermions are very heavy is usually evoked to suppress the
one-loop EDM contributions. We point out that under such a scheme the most
severe constraint may come from a new contribution to the electric dipole
moments of the electron, the neutron or atoms via the chargino sector at the
two-loop level. As a result, the allowed parameter space for baryogenesis in
MSSM is severely constrained, independent of masses of the first two generation
sfermions.


title: HTL Perturbation Theory to Two Loops

abstract:
  We calculate the pressure for pure-glue QCD at high temperature to two-loop
order using hard-thermal-loop (HTL) perturbation theory. At this order, all the
ultraviolet divergences can be absorbed into renormalizations of the vacuum
energy density and the HTL mass parameter. We determine the HTL mass parameter
by a variational prescription. The resulting predictions for the pressure fail
to agree with results from lattice gauge theory at temperatures for which they
are available.


title: Twist-3 Effects in Polarized Photon Structure

abstract:
  The polarized photon structure is described by two spin structure functions
$g_1^\gamma$ and $g_2^\gamma$ which can be studied in the future polarized ep
or e$^+$e$^-$ colliders. Here we investigate the QCD twist-3 effects in
$g_2^\gamma$ to the leading order in QCD.


title: Bose-Einstein correlations as reflection of correlations of fluctuations

abstract:
  Bose-Einstein correlations (BEC) observed between identical bosons produced
in high energy multiparticle collisions are regarded as very important tool in
investigations of multiparticle production processes. We present here their
stochastic feature stressing the fact that they can be regarded as a reflection
of correlations of fluctuations present in hadronizing system. We show in
particular that such approach allows for simple modelling of BEC in numerical
event generators used to describe the multiparticle production processes at
high energy collisions.


title: Unifying flipped SU(5) in five dimensions

abstract:
  It is shown that embedding a four-dimensional flipped SU(5) model in a
five-dimensional SO(10) model, preserves the best features of both flipped
SU(5) and SO(10). The missing partner mechanism, which naturally achieves both
doublet-triplet splitting and suppression of d=5 proton decay operators, is
realized as in flipped SU(5), while the gauge couplings are unified as in
SO(10). The masses of down quarks and charged leptons, which are independent in
flipped SU(5), are related by the SO(10). Distinctive patterns of quark and
lepton masses can result. The gaugino mass M_1 is independent of M_3 and M_2,
which are predicted to be equal.


title: A new determination of polarized parton densities in the nucleon

abstract:
  In order to determine polarized parton distributions we have made a new NLO
QCD fit using all experimental data on spin asymmetries measured in the deep
inelastic scattering on different nucleon targets. The functional form of such
densities is based on MRST 2001 results for unpolarized ones . We get for
polarization of quarks (at Q^2 = 1 GeV^2): Delta u = 0.87, Delta d = -0.38,
Delta s = -0.04. The total quark polarization is rather big and we obtain:
Delta Sigma = 0.44. As a result of our fit we get a_3 = g_A = 1.24 the value
which is close to experimental number. With negligible Delta s and rather big
Delta Sigma (comparable to a_8) the results of our new fit are quite different
in character from other fits.


title:
Geometric Origin of Large Lepton Mixing in a Higher Dimensional
  Spacetime

abstract:
  The large mixing in the lepton sector observed in the recent
neutrino-oscillation experiments strongly suggest that nature of left-handed
lepton doublets is very different from that of left-handed quark doublets. This
means that there is a big disparity between the matter multiplets 5^*'s and
10's in the SU(5) unified theory. We show that this big difference can be
explained in a six-dimensional spacetime compactified on the T^2/Z_3 orbifold.
That is, we propose to put three families of 5^*'s on three equivalent fixed
points of the orbifold and the three 10's in the two-dimensional bulk. We
construct an explicit model realizing this situation and show that the
democratic mass structure in the lepton sector is naturally obtained and hence
the model explains the observed bi-large lepton mixing and simultaneously the
required small mixing U_e3. The mass matrices and mixing in the quark sector
are also briefly discussed.


title: Large photon productions in a gravitational collapsing

abstract:
  We study a possible gravitational vacuum-effect, in which vacuum-energy
variation is due to variation of gravitational field, vacuum state gains
gravitational energy and releases it by spontaneous photon emissions. Based on
the path-integral representation, we present a general formulation of vacuum
transition matrix and energy-momentum tensor of a quantum scalar field theory
in curved spacetime. Using analytical continuation of dimensionality of the
phase space, we calculate the difference of vacuum-energy densities in the
presence and absence of gravitational field. Using the dynamical equation of
gravitational collapse, we compute the rate of vacuum state gaining
gravitational energy. Computing the transition amplitude from initial vacuum
state to final vacuum state in gravitational collapsing process, we show the
rate and spectrum of spontaneous photon emissions for releasing gravitational
energy. The possible connection of our study to the genuine origin of gamma ray
bursts is discussed. We compare our idea with the Schwinger idea for
Sonoluminiescence and contrast our scenario with the Hawking effect.


title: B^0_{d,s} - \bar{B}^0_{d,s} mass-differences from QCD spectral sum rules

abstract:
  We present the first QCD spectral sum rules analysis of the SU(3) breaking
parameter \xi and an improved estimate of the renormalization group invariant
(RGI) bag constant \hat{B}_{B_q} both entering into the B^0_{d,s} -
\bar{B}^0_{d,s} mass-differences. The averages of the results from the Laplace
and moment sum rules to order \alpha_s are f_B\sqrt{\hat B_B} \simeq (247 \pm
59) MeV and \xi \equiv f_{B_s} \sqrt{\hat B_{B_s}} / f_{B} \sqrt{\hat B_{B}}
\simeq (1.18\pm 0.03), in units where f_\pi=130.7 MeV. Combined with the
experimental data on the mass-differences \Delta M_{d,s}, one obtains the
constraint on the CKM weak mixing angle |V_{ts}/V_{td}|^2 > 20.0 (1.1).
Alternatively, using the weak mixing angle from the analysis of the unitarity
triangle and the data on \Delta M_d, one predicts \Delta M_s=18.6 (2.2) ps^{-1}
in agreement with the present experimental lower bound and within the reach of
Tevatron 2.


title: Orbifolded SU(7) and unification of families

abstract:
  A 5D SU(7) family unification model with two spinor representations of SO(14)
is presented. The fifth dimension is compactified on $S^1/Z_2\times Z_2'$. The
orbifolding is used to obtain 4D SO(10) chiral fermions. The 4D grand
unification group is the flipped $SU(5)\times U(1)$. The doublet-triplet
splitting through the missing partner mechanism is achieved. Also, fermion mass
matrices are considered.


title: On the possibility of a very light A^0 at low \tan\beta

abstract:
  The searches at LEP II for the processes e^+e^-\to h^0Z and e^+e^-\to h^0A^0
in the Minimal Supersymmetric Standard Model (MSSM) fail to exclude regions of
the m_h,m_A plane where \tan\beta <1, thus allowing a very light A^0 (m_A< 20
GeV). Such a parameter choice would predict a light H^\pm with m_{H^\pm}< m_W.
Although the potentially large branching ratio for H^\pm \to A^0 W^* would
ensure that H^\pm also escaped detection in direct searches at LEP II and the
Tevatron Run I, we show that this elusive parameter space is overwhelmingly
disfavoured by electroweak precision measurements.


title:
Color-SU(3)-Ginzburg-Landau Effective Potential for Order Parameter with
  ${\bf 3} \times {\bf 3}$ Symmetry

abstract:
  Ginzburg-Landau effective potential is studied for the order parameter that
transforms in the $(3,3)$ representation under the color SU(3) group. All the
SU(3) terms to the fourth-order of the order parameter are classified and the
effective potential is constructed in its most general form. The conditions
which stabilize the condensed phases are also obtained. As simple applications,
the classification of the condensed phase is discussed in some special cases
and the Higgs phenomenon associated with symmetry breaking is studied by
introducing a coupling to the gauge boson.


title: NLO Partonic Event Generators

abstract:
  Merging the benefits of an NLO calculation with event generators is a topic
of current interest. Among other things, it is advantageous to be able to
generate unweighted events according to NLO matrix elements. I report on an
algorithm which generates a sequence of unweighted momentum configurations,
each configuration containing either n or n+1 four-vectors, such that for any
infrared safe observable the average over these configurations coincides with
the NLO calculation up to errors of a resolution variable.


title: Radiative Return at NLO: the PHOKHARA Monte Carlo generator

abstract:
  Electron--positron annihilation into hadrons plus an energetic photon from
initial state radiation allows the hadronic cross-section to be measured over a
wide range of energies at high luminosity meson factories. A Monte Carlo
generator called PHOKHARA has been constructed, which simulates this process at
the next-to-leading order accuracy.


title: Effective description of the LOFF phase of QCD

abstract:
  We present an effective field theory for the crystalline color
superconductivity phase of QCD. It is kown that at high density and at low
temperature QCD exhibits a transition to a color superconducting phase
characterized by energy gaps in the fermion spectra. Under specific
circumstances the gap parameter has a crystalline pattern, breaking
translational and rotational invariance. The corresponding phase is the
crystalline color superconductive phase (or {\it LOFF} phase). We compute the
parameters of the low energy effective lagrangian describing the motion of the
free phonon in the high density medium and derive the phonon dispersion law.


title: Gravitational decays of heavy particles in large extra dimensions

abstract:
  In the framework of quantum gravity propagating in large extra dimensions, we
analyze the inclusive radiative emission of Kaluza-Klein spin-2 gravitons in
the two-fermions decays of massive gauge bosons, heavy quarks, Higgs bosons,
and in the two-massive gauge bosons decay of Higgs bosons. We provide
analytical expressions for the square modulus of amplitudes summed over
polarizations, and numerical results for the widths and branching ratios. The
corresponding decays in the Z, top quark, and Higgs boson sectors of the
standard model are analyzed in the light of present and future experiments.


title: B decays and Supersymmetry

abstract:
  I discuss how supersymmetry affects various observables in B decays, and
point out the interesting channels in the context of B factories.


title: Large lepton asymmetry from Q-balls

abstract:
  We propose a scenario which can explain large lepton asymmetry and small
baryon asymmetry simultaneously. Large lepton asymmetry is generated through
Affleck-Dine (AD) mechanism and almost all the produced lepton numbers are
absorbed into Q-balls (L-balls). If the lifetime of the L-balls is longer than
the onset of electroweak phase transition but shorter than the epoch of big
bang nucleosynthesis (BBN), the large lepton asymmetry in the L-balls is
protected from sphaleron effects. On the other hand, small (negative) lepton
numbers are evaporated from the L-balls due to thermal effects, which are
converted into the observed small baryon asymmetry by virtue of sphaleron
effects. Large and positive lepton asymmetry of electron type is often
requested from BBN. In our scenario, choosing an appropriate flat direction in
the minimal supersymmetric standard model (MSSM), we can produce positive
lepton asymmetry of electron type but totally negative lepton asymmetry.


title: Electroweak Hadronic Contributions to the muon g-2

abstract:
  We reanalyze the two-loop electroweak hadronic contributions to the muon g-2
that may be enhanced by large logarithms. The present evaluation is improved
over those already existing in the literature by the implementation of the
current algebra Ward identities and the inclusion of the correct short-distance
QCD behaviour of the relevant hadronic Green's function.


title: Radiative production of invisible charginos in photon photon collision

abstract:
  If in a supersymmetric model, the lightest chargino is nearly degenerate with
the lightest neutralino, the former can decay into the latter alongwith a soft
pion (or a lepton-neutrino pair). Near degeneracy of the chargino and
neutralino masses can cause the other decay products (the pion or the lepton)
to be almost invisible. Photon-photon colliders offer a possibility of clean
detection of such an event through a hard photon tag.


title:
Improving the discovery potential of charged Higgs bosons at the
  Tevatron and Large Hadron Collider

abstract:
  We outline several improvements to the experimental analyses carried out at
Tevatron (Run 2) or simulated in view of the Large Hadron Collider (LHC) that
could increase the scope of CDF/D0 and ATLAS/CMS in detecting charged Higgs
bosons


title: HERWIG: an event generator for MSSM processes

abstract:
  The HERWIG event generator was widely used throughout the workshop,
particularly in the emulation of Supersymmetric and Higgs processes in the
context of the Minimal Supersymmetric Standard Model. We briefly review here
its main features in this respect


title: Particle Physics Probes Of Extra Spacetime Dimensions

abstract:
  The possibility that spacetime is extended beyond the familiar 3+1-dimensions
has intrigued physicists for a century. Indeed, the consequences of a
dimensionally richer spacetime would be profound. Recently, new theories with
higher dimensional spacetimes have been developed to resolve the hierarchy
problem in particle physics. These scenarios make distinct predictions which
allow for experiment to probe the existence of extra dimensions in new ways. We
review the conceptual framework of these scenarios, their implications in
collider and short-range gravity experiments, their astrophysical and
cosmological effects, as well as the constraints placed on these models from
present data.


title:
Magnetic field of a neutron star with color superconducting quark matter
  core

abstract:
  The behaviour of the magnetic field of a neutron star with a superconducting
quark matter core is investigated in the framework of the Ginzburg-Landau
theory. We take into account the simultaneous coupling of the diquark
condensate field to the usual magnetic and to the gluomagnetic gauge fields. We
solve the Ginzburg-Landau equations by properly taking into account the
boundary conditions, in particular, the gluon confinment condition. We found
the distribution of the magnetic field in both the quark and hadronic phases of
the neutron star and show that the magnetic field penetrates into the quark
core in the form of quark vortices due to the presence of Meissner currents.


title: Quadrupole Moments of N and Delta in the 1/N_c Expansion

abstract:
  We calculate expressions for the quadrupole moments of nonstrange baryons in
which the number of QCD color charges is N_c. Using only the assumption of
single-photon exchange, we obtain 4 relations among the 6 moments, and show how
all of them may be obtained from Q_{\Delta^+ p} up to O(1/N_c^2) corrections.
We compare to the N_c=3 case, and obtain relations between the neutron charge
radius and quadrupole moments. We also discuss prospects for the measurement of
these moments.


title:
Light front Bethe-Salpeter equation applied to form factors, generalized
  parton distributions and generalized distribution amplitudes

abstract:
  We present an intuitive, light front reduction scheme for the Bethe-Salpeter
equation that consists of iterations of the (light front) energy dependent
covariant equation followed by an instantaneous approximation. This scheme is
equivalent to and motivates the form of a standard reduction that reproduces
light front, time ordered perturbation theory for bound states. We use this
three-dimensional light front formalism to compute electromagnetic form factors
between bound states to show how higher, light front Fock components arise from
the covariant Bethe-Salpeter wave function. Moreover, we show that non-wave
function vertices, which arise after integration over the minus momenta, are
completely removed in favor of higher Fock states when one correctly takes into
account all contributions at a given order in perturbation theory. Such
non-wave function vertices are shown only to occur in models in which the
interactions are instantaneous. These models lack true higher Fock states. The
normalization of the reduced wave function is derived from the covariant
framework and related to nonvalence probabilities using familiar Fock space
projection operators. Using a simple model, we obtain expressions for
generalized parton distributions that are continuous. The nonvanishing of these
distributions at the crossover between kinematic regimes (where the plus
component of the struck quark's momentum is equal to the plus component of the
momentum transfer) is tied to higher Fock components. Lastly we apply the light
front reduction to timelike form factors and derive expressions for the
generalized distribution amplitudes in this model.


title: Some aspects of particle physics in thermal background

abstract:
  The work in this thesis uses the formalism of thermal field theory. The major
problem considered by us is the gravitational interaction of charged leptons in
a medium. Working in the context of the linearized theory of gravity, we have
deduced general expressions for the matter-induced $O(\alpha)$ corrections to
the gravitational mass in normal matter background which contains electrons but
not the other charged leptons. Explicit formulas are then given for the
corrections in terms of the macroscopic parameters of the medium for a few
special cases of the background gases. In the last part of the thesis, we have
considered high-temperature, massless QED at zero chemical potential. We have
investigated the gauge independence of the one-loop electron dispersion
relation, taking subleading temperature dependence into account.


title: Neutrino mixing and large CP violation in B physics

abstract:
  We show that in see-saw models of neutrino mass a la SUSY SO(10), the
observed large mixing in atmospheric neutrinos naturally leads to large b-s
transitions. If the associated new CP phase turns out to be large, this SUSY
contributions can drastically affect the CP violation in some of the B decay
channels yielding the beta and gamma angles of the unitarity triangle. They can
even produce sizeable CP asymmetries in some decay modes which are not CP
violating in the standard model context. Hence the observed large neutrino
mixing makes observations of low energy SUSY effect in some CP violating decay
channels potentially promising in spite of the agreement between the Standard
Model and data in K and B physics so far.


title:
The decays of $B_c$ meson to P-wave charmonium $\chi_c(h_c)$ and to
  leptons with gluon bremsstrahlung

abstract:
  Theoretical computations on the decays of $B_c$ meson to $P$-wave charmonium
$\chi_c$ or $h_c$ with some particle(s) else and on the decays of $B_c$ meson
to leptons with gluon bremsstrahlung, and the results as well are outlined.


title:
Interpreting experimental bounds on D^0 - \bar{D^0} mixing in the
  presence of CP violation

abstract:
  We analyse the most recent experimental data regarding D^0 - \bar{D^0}
mixing, allowing for CP violation. We focus on the dispersive part of the
mixing amplitude, M^D_{12}, which is sensitive to new physics contributions. We
obtain a constraint on the mixing amplitude: |M^D_{12}| < 6.2\times 10^{-11}
MeV at 95% C.L. . This constraint is weaker by a factor of about three than the
one which is obtained when no CP violation is assumed.


title: Physics Potential of the Next Generation Colliders

abstract:
  In this article I summarize some aspects of the current status of the field
of high energy physics and discuss how the next generation of high energy
colliders will aid in furthering our basic understanding of elementary
particles and interactions among them, by shedding light on the mechanism for
the spontaneous breakdown of the Electroweak Symmetry.


title:
Role of nonperturbative input in QCD resummed heavy boson $Q_T$
  distribution

abstract:
  We show that role of nonperturbative input in the $b$-space QCD resummation
formalism for heavy boson transverse momentum ($Q_T$) distribution strongly
depends on collision energy $\sqrt{S}$. At collider energies, the larger
$\sqrt{S}$ is, the weaker role nonperturbative input plays, and better
predictive power the $b$-space resummation formalism has.


title: High-energy neutrino fluxes from supermassive dark matter

abstract:
  We calculate the fluxes and energy spectra of high-energy (E > 50 GeV)
neutrinos from the annihilations of supermassive (10^8 GeV < M < 10^16 GeV),
strongly interacting dark matter particles in the core of the Sun. We take all
significant aspects of neutrino propagation through matter into account, as
well as oscillations in matter and vacuum. We also calculate the resulting
event rates in an idealized 1 km^3 ice detector. We find that the signal should
be well above background and easily observed by next-generation neutrino
detectors such as IceCube.


title: Symmetries in collinear effective theory

abstract:
  We consider various symmetries present in the collinear effective theory and
their implications. There are collinear, soft and ultrasoft gauge symmetries
and we discuss transformation properties of a collinear quark and gauge fields
under these gauge transformations. If we require the gauge invariance order by
order, the gauge fields have definite transformation properties. We also probe
reparameterization invariance and residual energy invariance in the collinear
effective theory and discuss their physical consequences.


title:
Leading and higher twists in the proton polarised structure function g1p
  at large Bjorken-x

abstract:
  Power corrections to the Q**2 behavior of the Nachtmann moments of the proton
polarized structure function g1p are investigated at large Bjorken-x by
developing a phenomenological fit of both the resonance (including the photon
point) and deep inelastic data up to Q**2 ~ 50 (GeV/c)**2. The leading twist is
treated at NLO in the strong coupling constant and the effects of higher orders
of the perturbative series are estimated using soft-gluon resummation
techniques. In case of the first moment higher-twist effects are found to be
quite small for
  Q**2 > 1 (GeV/c)**2, and the singlet axial charge is determined to be a0[10
(GeV/c)**2] = 0.16 +/- 0.09. In case of higher order moments, which are
sensitive to the large-x region, higher-twist effects are significantly reduced
by the introduction of soft gluon contributions, but they are still relevant at
Q**2 ~ few (GeV/c)**2 at variance with the case of the unpolarized transverse
structure function of the proton. This finding suggests that spin-dependent
correlations among partons may have more impact than spin-independent ones. It
is also shown that the parton-hadron local duality is violated in the region of
polarized electroproduction of the Delta(1232) resonance.


title:
About one method of analytical calculations of reaction amplitudes with
  fermions

abstract:
  The paper presents the new method of calculations of reaction amplitudes of
processes with spin 1/2 fermions. The method is based on the application of
isotropic tetrad in Minkowski space and basis spinors connected with it. We
obtained as test and illustration of the method the amplitudes of interaction
processes $e^-e^+\to f \bar{f} $, $e^- e^+\to W^-W^+ $ and one of the possible
diagrams of the process $e^+e^-\to e^+e^-e^+e^-e^+e^-$.


title: Seminumerical resummation of event shapes and jet rates

abstract:
  For many observables, the most difficult part of a single logarithmic
resummation is the analytical treatment of the observable's dependence on
multiple emissions. We present a general numerical method, which allows the
resummation specifically of these single logarithms. Some first applications
and new results for the thrust major, the oblateness and the two-jet rate in
the Durham algorithm are also presented.


title: Finite width effects in \phi radiative decays

abstract:
  The decay widths \phi \to \gamma f_0(980) and \phi \to \gamma a_0(980) are
calculated taking into account the finite widths of the scalar resonances
f_0(980) and a_0(980). The latter are shown to be essential in order to obtain
meaningful results. Simultaneously we also study the decays \phi\to \gamma
\pi^0\pi^0 and \gamma \pi^0\eta where a good reproduction of the recent
experimental data is obtained, pointing out the necessity of a \phi\gamma
K^0\bar{K}^0 contact vertex. The calculated decay rates to \gamma f_0(980) and
\gamma a_0(980) are in good agreement with the experimental ones without
invoking isospin breaking in the couplings of the f_0(980) and a_0(980)
resonances to the K^+ K^- and K^0 \bar{K}^0 channels, at odds with recent
proposals. The derived formula for calculating these \phi radiative decay
widths can be also applied in their own experimental analyses in order to
obtain more precise results.


title: Black Holes at the LHC can Determine the Spin of Higgs Bosons

abstract:
  We propose a new method to determine the spin of Higgs bosons at the LHC by
using the decay products of black holes. Black holes may be produced if
TeV-scale gravity theories are correct, and black holes decay into several
particles. This decay results in the emission of high energy particles,
including Higgs bosons. The difference of the degree of freedom between spin 0
and spin 1 Higgs bosons leads to a difference of the number of reconstructed
Higgs bosons. From this fact, we can determine the spin of Higgs bosons with $5
\sigma$ significance by using the integrated luminosity L = 2.4 fb^-1, which
can be accumulated in only one month operation.


title: Nuclear Attenuation of Charged Mesons in Deep Inelastic Scattering

abstract:
  We propose extended version of stationary string model to describe the
nuclear attenuation. This model takes into account flavour content of particles
and allows to include into consideration all hadrons created from string.
  The predictions of the model are compared with experimental results obtained
by HERMES collaboration (DESY) on different nuclei (N and Kr).


title:
On the role of the strange quark and its mass in the chiral phase
  transition

abstract:
  The evolution of the chiral condensate with the temperature is studied using
SU(3) Chiral Perturbation Theory and the virial expansion. We observe a large
decrease of the melting temperature of the non-strange condensate compared with
the SU(2) case. Due to the larger mass of the strange quark we also find an
slower temperature evolution of the strange condensate compared with the
non-strange condensate.


title: The Infrared Behaviour of the Running Coupling in Landau Gauge QCD

abstract:
  Approximate solutions for the gluon and ghost propagators as well as the
running coupling in Landau gauge Yang-Mills theories are presented. These
propagators obtained from the corresponding Dyson-Schwinger equations are in
remarkable agreement with those of recent lattice calculations. The resulting
running coupling possesses an infrared fixed point, $\alpha_S(0) = 8.92/N_c$
for all gauge groups SU($N_c$). Above one GeV the running coupling rapidly
approaches its perturbative form.


title: (final) Higgs results from LEP

abstract:
  Contribution to "Rencontres de Moriond, QCD and hadronic interactions", Les
Arcs, France, March 2002


title: Multiparticle Production in QCD Jets

abstract:
  We briefly summarise the main results presented at the IPPP Workshop on
Multiparticle Production in QCD Jets, held in Durham in December 2001.


title: New results on inclusive quarkonium decays

abstract:
  I review some recent progress, leading to a substantial reduction in the
number of non-perturbative parameters, in the calculation of inclusive
quarkonium decay widths in the framework of non-relativistic effective field
theories.


title: Higgs boson decay rate into gluons in a 5 dimensional calculable model

abstract:
  In an extension of the Standard Model with one compact extra dimension and
N=1 supersymmetry, we compute the Higgs boson decay rate into two gluons,
relevant to the Higgs production in hadronic collisions. We find that at one
loop the decay width is significantly suppressed with respect to the SM. In
particular, for a compactification radius 1/R=370 /pm 70 GeV and a Higgs mass
m_H = 127 /pm 8 GeV we find it to be less than 15% of the SM result.


title:
The Behavior of Form Factors of Nucleon Resonances and Quark-Hadron
  Duality

abstract:
  A behavior of the nucleon structure functions in the resonance region is
investigated. Expressions for resonance production form factors, dependent on
photon virtuality $Q^2$, which have correct threshold behavior and take into
account available data on resonance decays, are obtained. Contributions of
resonances to nucleon structure functions are calculated. Obtained expressions
are used to investigate the quark-hadron duality in the electron-nucleon
scattering processes with the structure function $F_2$ as an example.


title: Testing neutrino mass matrices with approximate L_e-L_mu-L_tau symmetry

abstract:
  As neutrino experiments are starting to probe the detailed structure of the
neutrino mass matrix, we present sumrules relating its matrix elements for a
class of models with approximate $L_e-L_{\mu}-L_{\tau}$ symmetry and the
observables in neutrino oscillation experiments. We show that regardless of how
the above symmetry is broken (whether in the neutrino sector or the charged
lepton sector), as long as the breaking terms are small, there is a lower bound
on the solar neutrino mixing angle, $sin^22\theta_{\odot}$, correlated with the
solar mass difference square, $\Delta m^2_{\odot}$, or the mixing parameter,
$U_{e3}$. We also discuss models where such patterns can arise.


title: Jet Production at CDF

abstract:
  In this talk we present the results from the measurement of the inclusive jet
cross section and strong coupling constant based on the CDF Run 1B data, and
discuss prospects for Run 2.


title: Nonresonant Three-body Decays of D and B Mesons

abstract:
  Nonresonant three-body decays of D and B mesons are studied. It is pointed
out that if heavy meson chiral perturbation theory (HMChPT) is applied to the
heavy-light strong and weak vertices and assumed to be valid over the whole
kinematic region, then the predicted decay rates for nonresonant charmless
3-body B decays will be too large and especially B^- --> pi^- K^+ K^- greatly
exceeds the current experimental limit. This can be understood as chiral
symmetry has been applied there twice beyond its region of validity. If HMChPT
is applied only to the strong vertex and the weak transition is accounted for
by the form factors, the dominant B^* pole contribution to the tree-dominated
direct three-body B decays will become small and the branching ratio will be of
order 10^{-6}. The decay modes B^- --> (K^- h^+ h^-)_{NR} and bar{B}^0 -->
(bar{K}^0 h^+h^-)_{NR} for h = pi, K are penguin dominated. We apply HMChPT in
two different cases to study the direct 3-body D decays and compare the results
with experiment. Theoretical uncertainties are discussed.


title:
Constraint on the CKM angle alpha from the experimental measurements of
  CP violation in B_d^0 --> pi^+ pi^- decay

abstract:
  In this paper, we study and try to find the constraint on the CKM angle alpha
from the experimental measurements of CP violation in B_d^0 --> pi^+ pi^-
decay, as reported very recently by BaBar and Belle Collaborations. After
considering uncertainties of the data and the ratio r of penguin over tree
amplitude, we found that strong constraint on both the CKM angle alpha and the
strong phase delta can be obtained from the measured CP asymmetries S_{pi pi}
and A_{pi pi}: (a) the ranges of 87 degrees <= alpha <= 131 degrees and 36
degrees <= delta <= 144 degrees are allowed by 1 sigma of the averaged data for
r = 0.31; (b) for Belle's result alone, the limits on alpha and delta are 104
degrees <= alpha <= 139 degrees and 42 degrees <= delta <= 138 degrees for 0.32
<= r <= 0.41; and (c) the angle alpha larger than 90 degrees is preferred.


title: NNLO Analysis Of Semileptonic Rare B Decays

abstract:
  We update the standard model predictions for the branching ratios of the
decays B -> (K,K*,Xs) l^+ l^-, with l=e,mu. Using the measurements of BR(B ->
Xs gamma) and BR(B -> K l^+ l^-) as well as the upper limits on BR(B -> (K*,Xs)
l^+ l^-)$, we work out model independent bounds on the relevant Wilson
coefficients. We show the impact of such bounds on the parameter space of the
MSSM with minimal flavour violation and of supersymmetric models with
additional sources of flavour changing.


title:
Ratios of Antiparticle/Particle Yields in Hadron-Hadron and Heavy Ion
  Collisions

abstract:
  We compare the numerical results for antibaryon/baryon production ratios in
high energy heavy ion collisions with some theoretical models.


title: Anomaly Constraints and Number of Families

abstract:
  The purpose of this paper is to answer the following question : is it
possible to find a gauge group G and a space-time dimension D such that
anomalies constrain the fermion content to be composed of the 3 known families
of quarks and leptons ? The answer is, in some way, unique and consists in
taking an SU(5) gauge group in 6 dimensions. This work has been done with the
collaboration of N. Borghini and M. H. Tytgat.


title: The Nucleon-Nucleon Interaction in a Chiral Constituent Quark Model

abstract:
  This thesis constitute an investigation of finding out whether or not the
Goldstone Boson Exchange (GBE) model can give rise to a short-range repulsion
in the the nucleon-nucleon (NN) interaction. We used two different approaches
based on the Born-Oppenheimer approximation and taking into account Harvey's
transformations. Next, we study the NN interaction in a dynamical way using the
resonating group method (RGM). We present results for the s-wave phase shifts
in the NN scattering. We also introduce some necessary extensions of the GBE
model like the contribution of the sigma-meson exchange interaction between
quarks or the tensor force and discuss the comparison with the One Gluon
Exchange (OGE) results and experiment.


title:
Electron (positron) beam polarization by Compton scattering on
  circularly polarized laser photons

abstract:
  In a number of papers an attractive method of laser polarization of electrons
(positrons) at storage rings or linear colliders has been proposed. We show
that these suggestions are incorrect and based on errors in simulation of
multiple Compton scattering and in calculation of the Compton spin-flip cross
sections. We argue that the equilibrium polarization in this method is zero.


title: Muon g-2 in a Model with one Extra Dimension

abstract:
  The computation of the muon anomalous magnetic moment in the framework of a
proposed extension of the Standard Model to 5 dimensions is presented. The
result (a small correction with respect to the SM prediction) is briefly
discussed.


title:
Neutrinoless double $\beta$ decay, neutrino mass hierarchy, and neutrino
  dark matter

abstract:
  Recently the evidence of the neutrinoless double $\beta$ ($0\nu \beta\beta$)
decay has been announced. This means that neutrinos are Majorana particles and
their mass hierarchy is forced to inverted mass hierarchy (Type B) or
degenerate mass (Type C) patterns in the diagonal basis of charged lepton mass
matrix. We estimate the magnitude of $0\nu \beta\beta$ decay in the degenerate
neutrinos including the cosmological constraint of neutrino dark matter, since
the inverted mass hierarchy pattern always satisfies the cosmological
constraint. The absolute value of neutrino mass is constrained by $0\nu
\beta\beta$ experiment or cosmology depending on the relative signs (Majorana
CP phases) of neutrino masses.


title: Gauge symmetry breaking on orbifolds

abstract:
  We discuss a new method for gauge symmetry breaking in theories with one
extra dimension compactified on the orbifold S^1/Z_2. If we assume that fields
and their derivatives can jump at the orbifold fixed points, we can implement a
generalized Scherk-Schwarz mechanism that breaks the gauge symmetry. We show
that our model with discontinuous fields is equivalent to another with
continuous but non periodic fields; in our scheme localized lagrangian terms
for bulk fields appear.


title:
The Flavour Hierarchy and See-Saw Neutrinos from Bulk Masses in 5d
  Orbifold GUTs

abstract:
  In supersymmetric grand unified theories (GUTs) based on S^1/(Z_2 x Z'_2)
orbifold constructions in 5 dimensions, Standard Model (SM) matter and Higgs
fields can be realized in terms of 5d hypermultiplets. These hypermultiplets
can naturally have large bulk masses, leading to a localization of the zero
modes at one of the two branes or to an exponential suppression of the mass of
the lowest-lying non-zero mode. We demonstrate that these dynamical features
allow for the construction of an elegant 3-generation SU(5) model in 5
dimensions that explains all the hierarchies between fermion masses and CKM
matrix elements in geometrical terms. Moreover, if U(1)_\chi (where SU(5) x
U(1)_\chi \subset SO(10)) is gauged in the bulk, but broken by the orbifold
action at the SM brane, the right-handed neutrino mass scale is naturally
suppressed relative to M_GUT. Together with our construction in the charged
fermion sector this leads, via the usual see-saw mechanism, to a realistic
light neutrino mass scale and large neutrino mixing angles.


title: Final State Interactions in Hadronic WW Decay at LEP

abstract:
  An overview is given of the study of final state interactions in hadronically
decaying W pairs produced in e^+e^--collisions as it is performed by the four
LEP experiments. Bose-Einstein correlations are investigated by comparing like-
with unlike-signed pairs of pions and/or using the mixed event analysis
technique. Colour reconnection is examined with a method that compares the
particle flow distributions in inter-jet regions.


title:
Aspects of the unitarized soft multipomeron approach in DIS and
  diffraction

abstract:
  We study in detail the main features of the unitarized Regge model (CFKS),
recently proposed to describe the small-$Q^2$ domain. It takes into account a
two-component description with two types of unitarized contributions: one is
the multiple Pomeron exchanges contribution, interacting with the large dipole
size configurations, and the other one consists on a unitarized dipole cross
section, describing the interaction with the small size dipoles. We compare the
resulting dipole cross section to that from the saturation model (GBW).


title: Measuring Higgs Coupling to Tau-Leptons at Future e+ e- Colliders

abstract:
  We perform a complete simulation of the process $ e^+ e^- \to \tau^+ \tau^-
\nu \bar{\nu}$, where $\nu$ can be an electron, muon or tau neutrino, in the
context of a general Higgs coupling to $\tau$ leptons. We analyse various
kinematical distributions and obtain the sensitivity regions in the parameter
space that can be explored at a future $e^+ e^-$ collider. In particular,
inclusion of $W$ boson fusion enhances the sensitivity significantly.


title: Renormalization Invariants of the Neutrino Mass Matrix

abstract:
  The renormalization evolution of all parameters in the neutrino mass matrix
depends only on one variable, the energy scale. This fact, coupled with
rephasing considerations, leads to a set of renormalization invariants,
correlating the evolution of physical parameters. For the general three flavor
case, we obtain these invariants explicitly and discuss their implications.


title: Enhanced subleading structure functions in semileptonic B decay

abstract:
  The charged lepton spectrum in semileptonic $B\to X_u \ell\bar\nu$ decay near
maximal lepton energy receives important corrections from subleading structure
functions that are formally suppressed by powers of $\Lambda_{QCD}/m_b$ but are
enhanced by numerical factors. We investigate the series of higher order terms
which smear over a region of width $\Delta E_\ell \sim \Lambda_{QCD}$ near the
endpoint the contributions proportional to $\delta(E_\ell - m_b/2)$ times (i)
the matrix element of the chromomagnetic operator, and (ii) four-quark
operators. These contribute to the total rate at the few percent level, but
affect the endpoint region much more significantly. Implications for the
determination of $|V_{ub}|$ are discussed.


title: The Leading Particle Effect from Heavy-Quark Recombination

abstract:
  The leading particle effect in charm hadroproduction is an enhancement of the
cross section for a charmed hadron D in the forward direction of the beam when
the beam hadron has a valence parton in common with the D. The large D+/D-
asymmetry observed by the E791 experiment is an example of this phenomenon. We
show that the heavy-quark recombination mechanism provides an economical
explanation for this effect. In particular, the D+/D- asymmetry can be fit
reasonably well using a single parameter whose value is consistent with a
recent determination from charm photoproduction.


title:
Subleading shape functions in B -> X_u l \nu and the determination of
  |Vub|

abstract:
  We calculate the subleading twist contributions to the endpoint of the
inclusive lepton energy spectrum in B -> X_u l \nu. We show that the same two
subleading twist functions that appear in the decay B -> X_s \gamma govern the
subleading effects in this decay. Using these results we find large
O(Lambda/mB) corrections to the determination of |Vub| from the endpoint of the
charged lepton spectrum. Using a simple model for the relevant subleading shape
functions, we estimate the uncertainty in |Vub| from Lambda/mb corrections to
be at the ~ 15% level for a lower lepton energy cut of 2.2 GeV.


title: Gluon Shadowing and Heavy Flavor Production off Nuclei

abstract:
  Gluon shadowing which is the main source of nuclear effects for production of
heavy flavored hadrons, remains unknown. We develop a light-cone dipole
approach aiming at simplifying the calculations of nuclear shadowing for heavy
flavor production, as well as the cross section which does not need
next-to-leading and higher order corrections. A substantial process dependence
of gluon shadowing is found at the scale of charm mass manifesting a deviation
from QCD factorization. The magnitude of the shadowing effect correlates with
the symmetry properties and color state of the produced c-cbar pair. It is
about twice as large as in DIS, but smaller than for charmonium production. The
higher twist shadowing correction related to a nonzero size of the c-cbar pair
is not negligible and steeply rises with energy. We predict an appreciable
suppression by shadowing for charm production in heavy ion collisions at RHIC
and a stronger effect at LHC. At the same time, we expect no visible difference
between nuclear effects for minimal bias and central collisions, as is
suggested by recent data from the PHENIX experiment at RHIC. We also
demonstrate that at medium high energies when no shadowing is possible, final
state interaction may cause a rather strong absorption of heavy flavored
hadrons produced at large x_F.


title:
Inclusive Higgs Boson Production at Hadron Colliders at
  Next-to-Next-to-Leading Order

abstract:
  Inclusive production via gluon fusion will be the most important production
channel for Higgs boson discovery at the LHC. I report on a calculation of the
inclusive Higgs boson production cross section at $pp$ and $p\bar p$ colliders
at next-to-next-to-leading order in QCD.


title:
Uncertainties on parton distribution functions from the ZEUS NLO QCD fit
  to data on deep inelastic scattering

abstract:
  An NLO QCD analysis of the ZEUS data on $e^+ p$ deep inelastic scattering
together with fixed-target data has been performed from which the gluon and
quark densities of the proton and the value of the strong coupling parameter,
$\alpha_s(M_Z^2)$, have been extracted. The study includes a full treatment of
the experimental systematic uncertainties, including point-to-point
correlations. Different ways of incorporating correlated systematic
uncertainties into the fit are discussed and compared.


title: Understanding the Fierz Ambiguity of Partially Bosonized Theories

abstract:
  A useful tool in non perturbative studies of fermionic theories is partial
bosonization. However, partial bosonization is often connected to an ambiguity
due to Fierz rearrangement in the original theory. We discuss two different
approximations for the calculation of the effective action $\Gamma$ with
respect to a spurious dependence on the choice of Fierz transformation: Mean
field theory and the truncated flow of an exact renormalization group equation
for the effective average action.


title: Z Production as a Test of Nuclear Effects at the LHC

abstract:
  We predict the Z transverse momentum distribution from proton-proton and
nuclear collisions at the LHC. After demonstrating that higher-twist nuclear
effects are very small, we propose $Z^0$ production as a precision test for
leading-twist pQCD in the TeV energy region. We also point out that shadowing
may result in unexpected phenomenology at the LHC.


title:
Superposition effect and clan structure in forward-backward multiplicity
  correlations

abstract:
  The main purpose of this paper is to discuss the link between
forward-backward multiplicity correlations properties and the shape of the
corresponding final charged particle multiplicity distribution in various
classes of events in different collisions. It is shown that the same mechanism
which explains the shoulder effect and the H_n vs. n oscillations in charged
particle multiplicity distributions, i.e., the weighted superposition of
different classes of events with negative binomial properties, reproduces
within experimental errors also the forward-backward multiplicity correlation
strength in e+e- annihilation at LEP energy and allows interesting predictions
for pp collisions in the TeV energy region, to be tested at LHC, for instance
with the ALICE detector. We limit ourselves at present to study substructures
properties in hadron-hadron collisions and e+e- annihilation; they are examined
as ancillary examples in the conviction that their understanding might be
relevant also in other more complex cases.


title:
Heavy to Light Meson Exclusive Semileptonic Decays in Effective Field
  Theory of Heavy Quark

abstract:
  We present a general study on exclusive semileptonic decays of heavy (B, D,
B_s) to light (pi, rho, K, K^*) mesons in the framework of effective field
theory of heavy quark. Transition matrix elements of these decays can be
systematically characterized by a set of wave functions which are independent
of the heavy quark mass except for the implicit scale dependence. Form factors
for all these decays are calculated consistently within the effective theory
framework using the light cone sum rule method at the leading order of 1/m_Q
expansion. The branching ratios of these decays are evaluated, and the heavy
and light flavor symmetry breaking effects are investigated. We also give
comparison of our results and the predictions from other approaches, among
which are the relations proposed recently in the framework of large energy
effective theory.


title: T-Odd Correlations in pi->e nu_e gamma and pi->mu nu_mu gamma Decays

abstract:
  The transverse lepton polarization asymmetry in pi_l2gamma decays may probe
T-violating interactions beyond the Standard Model. Dalitz plot distributions
of the expected effects are presented and compared to the contribution from the
Standard Model final state interactions. We give an example of a
phenomenologically viable model, where a considerable contribution to the
transverse lepton polarization asymmetry arises.


title: Virtual photon structure functions and positivity constraints

abstract:
  We study the three positivity constraints among the eight virtual photon
structure functions, derived from the Cauchy-Schwarz inequality and which are
hence model-independent. The photon structure functions obtained from the
simple parton model show quite different behaviors in a massive quark or a
massless quark case, but they satisfy, in both cases, the three positivity
constraints. We then discuss an inequality which holds among the unpolarized
and polarized photon structure functions $F_1^\gamma$, $g_1^\gamma$ and
$W_{TT}^\tau$, in the kinematic region $\Lambda^2\ll P^2 \ll Q^2$, where $-Q^2
(-P^2)$ is the mass squared of the probe (target) photon, and we examine
whether this inequality is satisfied by the perturbative QCD results.


title: The MSSM Higgs bosons in the intense-coupling regime

abstract:
  We perform a comprehensive study of the Higgs sector of the Minimal
Supersymmetric extension of the Standard Model in the case where all Higgs
bosons are rather light, with masses of ${\cal O}(100 GeV)$, and couple
maximally to electroweak gauge bosons and strongly to standard third generation
fermions, i.e. for large values of the ratio of the vacuum expectation values
of the two Higgs doublet fields, $\tan \beta$. We first summarize the main
phenomenological features of this "intense-coupling" scenario and discuss the
available constraints from direct searches of Higgs bosons at LEP2 and the
Tevatron as well as the indirect constraints from precision measurements such
as the $\rho$ parameter, the $Zb\bar{b}$ vertex, the muon $(g-2)$ and the decay
$b\to s \gamma$. We then analyze the decay branching fractions of the neutral
Higgs particles in this regime and their production cross sections at the
upcoming colliders, the Tevatron Run II, the LHC, a 500 GeV $e^+e^-$ linear
collider (in the $e^+e^-$ and $\gamma \gamma$ options) as well as at a $\mu^+
\mu^-$ collider.


title: DIS event-shape resummations and spin-offs

abstract:
  We present results from a recently completed project to calculate
next-to-leading logarithmic resummed distributions for a variety of event
shapes in the 1+1-jet limit of DIS. This allows fits for the strong coupling
and for non-perturbative effects using the large amount of data on these
observables from HERA. Spin-offs include the discovery of a new class of logs
for certain final state observables (non-global observables); a program that
allows a speed-up by an order of magnitude of certain fixed-order calculations
in DIS with DISENT or DISASTER++; and the development of state-of-the-art PDF
evolution code.


title: The one-loop functional of chiral SU(2)

abstract:
  The one-loop functional for chiral SU(2) of Gasser and Leutwyler is extended
to include up to three propagators. With this generating functional it is
possible to calculated all amplitudes up to order phi^6 to next-to-leading
order in the low-energy expansion. An external pion is of order phi and a
vector gauge boson is of order phi^2. A check of the existing amplitudes for
two photons into two pions is given. The one-loop amplitudes and the cross
sections for four-pion production in e^+e^- annihilation are calculated.


title: Present Status of experimental determination of Vcb

abstract:
  The present status of our knowledge of the magnitude of the quark mixing
parameter Vcb is reviewed, with particular emphasis on the factors affecting
experimental and theoretical errors and on prospects for a more precise
determination.


title:
CP-violation and $\pi\pi$-interaction in the radiative decays of $K_L$
  and $K_S$

abstract:
  The phases of terms of amplitude that arise from the $\pi\pi$ interaction are
obtained by using a simple realistic model of $\pi\pi$ interaction via virtual
$\rho$-meson, instead of the ChPT. It is shown that the standard ChPT approach
cannot reproduce the contribution of the $\rho$-meson to the $\pi\pi$
interaction. It is shown that the interference between the terms of amplitude
with different CP-parity appears only when the photon is polarized (linearly or
circularly). Instead of measuring the linear polarization, the angular
correlation between the $\pi^{+}\pi^{-}$ and $e^{+}e^{-}$ planes in
$K_{S,L}\to\pi^{+}\pi^{-}e^{+}e^{-}$ decay can be studied.


title: The Feynman-Schwinger representation in QCD

abstract:
  The proper time path integral representation is derived explicitly for
Green's functions in QCD. After an introductory analysis of perturbative
properties, the total gluonic field is separated in a rigorous way into a
nonperturbative background and valence gluon part. For nonperturbative
contributions the background perturbation theory is used systematically,
yielding two types of expansions,illustrated by direct physical applications.
As an application, we discuss the collinear singularities in the
Feynman-Schwinger representation formalism. Moreover, the generalization to
nonzero temperature is made and expressions for partition functions in
perturbation theory and nonperturbative background are explicitly written down.


title: Two-loop corrections to the Higgs boson masses in the MSSM

abstract:
  We present a computation of the O(at*as + at^2) two--loop corrections to the
MSSM Higgs masses. An appropriate use of the effective potential approach
allows us to obtain simple analytical formulae, valid for arbitrary values of
mA and of the mass parameters in the stop sector. In a large region of the
parameter space the O(at^2) corrections are comparable to the O(at*as) ones,
increasing the prediction for mh by several GeV.


title: The Energy Dependence of the Saturation Momentum

abstract:
  We study BFKL evolution and, in particular, the energy dependence of the
saturation momentum in the presence of saturation boundaries limiting the
region of linear BFKL evolution. In the case of fixed coupling evolution we
confirm the previously found exponential term in $Q_s(Y)$ and determine the
prefactor $Y$ and $\alpha$ dependences. In the running coupling case we find
$Y^{1/6}$ corrections to the $Y^{1/2}$exponential behavior previously known.
Geometrical scaling of the scattering amplitude is valid in a wide-range of
momenta for fixed coupling evolution and in a more restricted region for
running coupling evolution.


title: A New Era in High-energy Physics

abstract:
  In TeV-scale gravity, scattering of particles with center-of-mass energy of
the order of a few TeV can lead to the creation of nonperturbative, extended,
higher-dimensional gravitational objects: Branes. Neutral or charged, spinning
or spinless, Einsteinian or supersymmetric, low-energy branes could
dramatically change our picture of high-energy physics. Will we create branes
in future particle colliders, observe them from ultra high energy cosmic rays,
and discover them to be dark matter?


title:
Measuring the Phase Velocity of Light in a Magnetic Field with the PVLAS
  Detector

abstract:
  A method is suggested for measuring the velocity of light in a magnetic field
using the PVLAS detector. It is proposed to modulate the linear polarization of
the input light. In that case the feedback signal necessary to keep the high
finesse Fabry-Perot cavity on resonance is a measure of the change in the speed
of light for the two orthogonal polarizations.


title: New Higgs signals induced by mirror fermion mixing effects

abstract:
  We study the conditions under which flavor violation arises in scalar-fermion
interactions, as a result of the mixing phenomena between the standard model
and exotic fermions. Phenomenological consequences are discussed within the
specific context of a left-right model where these additional fermions have
mirror properties under the new SU(2)_R gauge group.
  Bounds on the parameters of the model are obtained from LFV processes; these
results are then used to study the LFV Higgs decays (H --> tau l_j, l_j = e,
mu), which reach branching ratios that could be detected at future colliders.


title: Fresh inflation with nonminimally coupled inflaton field

abstract:
  I study a fresh inflationary model with a scalar field nonminimally coupled
to gravity. An example is examined. I find that, as larger is the value of $p$
(the power of the scale factor), smaller (but larger in its absolute value) is
the necessary value of the coupling $\xi$ to the inflaton field fluctuations
can satisfy a scale invariant power spectrum.


title:
O(\alpha^2 \ln(m_\mu/m_e)) Corrections to Electron Energy Spectrum in
  Muon Decay

abstract:
  O(\alpha^2 \ln(m_\mu/m_e)) corrections to electron energy spectrum in muon
decay are computed using perturbative fragmentation function approach. The
magnitude of these corrections is comparable to anticipated precision of the
TWIST experiment at TRIUMF where Michel parameters will be extracted from the
measurement of the electron energy spectrum in muon decay.


title: Electric Charge Quantization and Extra Dimensions

abstract:
  In models with flat extra dimensions tiny Dirac neutrino masses can be
generated via the coupling of four dimensional Standard Model fields to a
higher dimensional fermion. Here we argue that, in spite of the Dirac nature of
the neutrino, quantization of the electric charge can still be understood as a
result of anomaly cancellation, charge conservation and naturalness
requirements.


title: Black Holes at Future Colliders and Beyond

abstract:
  One of the most dramatic consequences of low-scale (~1 TeV) quantum gravity
is copious production of mini black holes at future accelerators and in
ultra-high-energy cosmic ray interactions. Hawking radiation of these black
holes is constrained mainly to our (3+1)-dimensional world and results in rich
phenomenology. We discuss tests of Wien's law of Hawking radiation, which is a
sensitive probe of the dimensionality of extra space, as well as an exciting
possibility of finding new physics in the decays of black holes.


title:
Novel type of color solitons with topological charge not coinciding with
  baryon number and extended chiral group E$\chi $

abstract:
  We consider extended chiral group $E\chi $ of gauge plus chiral
transformations of the quark path integral in the background gauge and present
novel type of color solitons described by the effective action resulting from
bosonization. O(3) solitons are formed by a chiral field including parameters
with diquark quantum numbers within symplectic subgroup of $E\chi $, as well as
within complete $E\chi $; isolated solitons (i.e. solitons in gluonic vacuum)
can be stable due to proper asymptotics induced by background vacuum, their
topological charge starts from $\pm \frac 43$ and does not coincide with the
baryon number, as if notions of left anf right were dependent also on
non-abelian directions in such a SU(2) group, where the baryon number defines a
diagonal generator.


title: R Parity violating enhancement of Bu -> l nu and Bc -> l nu

abstract:
  We study the decays Bu -> l nu and Bc -> l nu in the context of the Minimal
Supersymmetric Standard Model (MSSM) with explicit R parity violation. We
analyse the correlation between the two decays and show that branching ratios
(BRs) for Bc -> l nu may be of order 5% (over 40% in one case), without
violating current bounds on Bu -> l nu. Although Bc mesons are inaccessible at
the e+e- B factories, such large BRs for Bc -> l nu would possibly be within
experimental observability at LEP and the Tevatron Run II, with much larger
yields expected at the hadronic B factories. We also update some earlier bounds
on products of R parity violating couplings in the light of new experimental
results.


title: Pion Generalized Parton Distributions in the Non-Local NJL Model

abstract:
  We calculate skewed parton distributions $H^I$ of a pion within a non-local
NJL model with momentum dependent constituent quark mass $M(k)$. In the forward
limit $H^I$ correspond to parton distributions, whereas for $t<0$, $H^I$ is
related to the pion electromagnetic form-factor


title: Charginos and Neutralinos at e+e- Linear Colliders

abstract:
  It is shown how the fundamental gaugino and higgsino parameters of the
chargino and neutralino system in the MSSM can completely be determined in
high--precision experiments at e+e- linear colliders even if in their initial
phase only the light charginos $\tilde{\chi}^\pm_1$ and the light neutralinos
$\tilde{\chi}^0_1$ and $\tilde{\chi}^0_2$ are kinematically accessible.


title:
Higgs mass sensitivity and localization due to Fayet-Iliopoulos terms on
  5D orbifolds

abstract:
  In this talk we review calculations of FI-tadpoles in 5 dimensional
(non-)supersymmetric orbifold theories. Some consequences of these tadpoles are
discussed: quadratic Higgs-mass sensitivity to a high scale, and localization
of bulk matter fields to the orbifold fixed points.


title: Five Adjustable Parameter Fit of Quark and Lepton Masses and Mixings

abstract:
  We develop a model of ours fitting the quark and lepton masses and mixing
angles by removing from the model a Higgs field previously introduced to
organise a large atmospheric mixing angle for neutrino oscillations. Due to the
off-diagonal elements dominating in the see-saw neutrino mass matrix the large
atmospheric mixing angle comes essentially by itself. It turns out that we have
now only five adjustable Higgs field vacuum expectation values needed to fit
all the masses and mixings order of magnitudewise taking into account the
renormalisation group runnings in all sectors. The CHOOZ angle comes out close
to the experimental bound.


title: Lattice QCD

abstract:
  A general introduction to lattice QCD suitable for graduate students in
experimental and theoretical particle physics. Aimed at those who want to know
how lattice calculations are done, and what the pitfalls are, without having to
do the calculations themselves.


title:
A Novel Mechanism of H^0 Di-baryon Production in Proton-Proton
  Interactions from Parton Based Gribov-Regge Theory

abstract:
  A novel mechanism of H^0 and strangelet production in hadronic interactions
within the Gribov-Regge approach is presented. In contrast to traditional
distillation approaches, here the production of multiple (strange) quark bags
does not require large baryon densities or a QGP. The production cross section
increases with center of mass energy. Rapidity and transverse momentum
distributions of the H^0 are predicted for pp collisions at E_lab = 160 AGeV
(SPS) and \sqrt s = 200 AGeV (RHIC). The predicted total H^0 multiplicities are
of order of the Omega-baryon yield and can be accessed by the NA49 and the STAR
experiments.


title: Parity-Violating Electron Scattering as a Probe of Supersymmetry

abstract:
  We compute the one-loop supersymmetric (SUSY) contributions to the weak
charges of the electron ($Q_W^e$) and proton ($Q_W^p$) using the Minimal
Supersymmetric Standard Model (MSSM). These $q^2=0$ vector couplings of the
$Z^0$-boson to fermions will be determined in two fixed-target,
parity-violating electron scattering experiments. The SUSY loop contributions
to $Q_W^p$ and $Q_W^e$ can be substantial, leading to several percent
corrections to the Standard Model values for these quantities. We show that the
relative signs of the SUSY loop effects on $Q_W^e$ and $Q_W^p$ are correlated
and positive over nearly all of the MSSM parameter space, whereas inclusion of
R-parity nonconserving interactions can lead to opposite sign relative shifts
in the weak charges. Thus, a comparison of $Q_W^p$ and $Q_W^e$ measurements
could help distinguish between different SUSY scenarios.


title:
Challenges in the calculation of next-to-next-to-leading order
  scattering processes

abstract:
  We discuss the status of the next-to-next-to-leading order calculation in
scattering processes, describing briefly the challenges that have been overcome
and what challenges are still to be resolved.


title:
Two-Loop Analysis of Gauge Coupling Unification with Anomalous U(1)
  Symmetry and Proton Decay

abstract:
  Recently, a new mechanism, which explains why the three gauge coupling
constants meet at a certain scale in the minimal supersymmetric standard model,
has been proposed in a scenario of grand unified theories with anomalous
$U(1)_A$ gauge symmetry. It is a non-trivial result that although there are
many superheavy fields whose mass scales are below the unification scale, this
mechanism explains this fact by means of one-loop renormalization group
equations. Since the unification scale generically becomes below the usual GUT
scale, $2\times 10^{16}$ GeV, and proton decay via dimension 5 operators is
suppressed, the scenario predicts that proton decay via dimension 6 operators,
$p\to e \pi^0$, will be observed in the near future. In this paper, we attempt
to estimate a reasonable range of values of the lifetime of the proton
predicted within this scenario by using a two-loop renormalization group
calculation and the ambiguities of \order1 coefficients.


title: Thermal QCD sum rules for mesons

abstract:
  A recently proposed scheme is used to saturate the spectral side of the QCD
sum rules derived from the thermal, two-point correlation functions of the
vector and the axial-vector currents. At low temperature, it constructs the
spectral representation from all the one-loop Feynman diagrams for the
two-point functions. The old saturation scheme treats incorrectly some of these
contributions. We end up with the familiar QCD sum rules obtained from the
difference of the two corresponding vacuum correlation functions. The
possibility of obtaining new sum rules in other media is discussed.


title: OPE and Powers corrections on the QCD coupling constant

abstract:
  The running coupling constant can be estimated by computing gluon two- and
three-point Green functions from the lattice. Computing in lattice implies
working in a fixed gauge sector (Landau). An source of systematic uncertainty
is then the contribution of non gauge-invariant condensates, as $<A^2 >$,
generating power corrections that might still be important at very high
energies. We study the impact of this gluon condensate on the analysis of gluon
propagator and vertex lattice data and on the estimate of $\Lambda_{\bar{\rm
MS}}$. We finally try a qualitative description of this gluon condensate
through the instanton picture


title: Time advancement in resonance regions of pi-N scattering

abstract:
  We evaluate the time delay in some of the established resonance regions of
$\pi N$ elastic scattering. In addition to the positive peaks corresponding to
resonances, we identify broad regions of negative time delay or time
advancement which restrict the energy ranges within which the resonances can be
located.


title:
Phenomenological approach to symmetry breaking pattern of democratic
  mass matrix

abstract:
  We investigate the symmetry breaking pattern of the democratic mass matrix
model, which leads to the small flavor mixing in quark sector and bi-large
mixing in lepton sector. We present the symmetry breaking matrices in quark
sector which are determined by alternative ways instead of conventional ansatz.
These matrices might be useful for understanding the origin of democratic
symmetry and its breaking.


title: New quantum (anti)de Sitter algebras and discrete symmetries

abstract:
  Two new quantum anti-de Sitter so(4,2) and de Sitter so(5,1) algebras are
presented. These deformations are called either time-type or space-type
according to the dimensional properties of the deformation parameter. Their
Hopf structure, universal R matrix and differential-difference realization are
obtained in a unified setting by considering a contraction parameter related to
the speed of light, which ensures a well defined non-relativistic limit. Such
quantum algebras are shown to be symmetry algebras of either time or space
discretizations of wave/Laplace equations on uniform lattices. These results
lead to a proposal fortime and space discrete Maxwell equations with quantum
algebra symmetry.


title:
Absolute neutrino masses: physics beyond SM, double beta decay and
  cosmic rays

abstract:
  Absolute neutrino masses provide a key to physics beyond the standard model.
We discuss the impact of absolute neutrinos masses on physics beyond the
standard model, the experimental possibilities to determine absolute neutrinos
masses, and the intriguing connection with the Z-burst model for extreme-energy
cosmic rays.


title: Faces of quark matter

abstract:
  Based on an analysis in the framework of a coalescence hadronization model
(ALCOR) we conclude that in heavy ion collisions at CERN SPS and RHIC energies
a new type of matter, the massive quark-antiquark matter is produced.


title: Presentations from DIS2002 in Krakow

abstract:
  Both of my talks at DIS2002, on Generalised Parton Distributions and Nuclear
Shadowing are presented. In an appendix I summarise some of the discussions
which followed the talks.


title: Unitarity constraints and role of geometrical effects

abstract:
  Unitarity and geometrical effects are discussed for photon--photon
scattering.


title:
CP Violating Asymmetries in the Flavor Changing Single Top Quark
  Production

abstract:
  CP violating effects in the single top quark production via flavour changing
neutral current (FCNC) reactions $e^+e^- ->t bar{q}$ and $e^+e^- ->bar{t}q$
(here $q$ refers to charm and up quarks) are studied. The effective Lagrangian
description of the FCNC interactions is used. A numerical analysis is performed
for some next linear colliders. CP violating asymmetries for the number of $q$
and $\bar{q}$ quarks are obtained to be of order $10^{-2}-10^{-3}$ depending on
the CM energy.


title: Soft Gluons and the Energy Dependence of Total Cross-Sections

abstract:
  We discuss the high energy behaviour of total cross-sections for protons and
photons, in a QCD based framework with particular emphasis on the role played
by soft gluons


title: Total Cross-sections

abstract:
  We examine the energy dependence of total cross-sections for photon processes
and discuss the QCD contribution to the rising behaviour


title: Understanding Geometric Scaling at Small x

abstract:
  Geometric scaling is a novel scaling phenomenon observed in deep inelastic
scattering at small x: the total virtual photon-proton cross section depends
upon the two kinematical variables Q^2 and x only via their combination Q^2
R_0^2(x), with R_0^2(x) \propto x^{\lambda}. At sufficiently low Q^2, below the
saturation scale Q_s^2(x) (a few GeV^2), this phenomenon finds a natural
explanation as a property of the Color Glass Condensate, the high-density
matter made of saturated gluons. To explain the experimental observation of
geometric scaling up to much higher values of Q^2, of the order of 100 GeV^2,
we study the solution to the BFKL equation subjected to a saturation boundary
condition at Q^2\sim Q_s^2(x). We find that the scaling extends indeed above
the saturation scale, within a window 1 < \ln(Q^2/Q_s^2) <<
\ln(Q_s^2/\Lambda^2_{\rm QCD}), which is consistent with phenomenology.


title:
New Potential of Black Holes : Quest for TeV-Scale Physics by Measuring
  Top Quark Sector using Black Holes

abstract:
  If TeV-scale gravity models are correct, the production of black holes will
be the first signal of new physics. Once black holes are produced, they will
give us much information about TeV-scale new physics directly. But such black
holes can also be used for the precision measurements of the Standard Model
(SM). The SM is nothing but a theory which can describe weak-scale, and
TeV-scale physics will affect it. So if some experimental results which cannot
be explained in the SM are found, they will be attributed to TeV-scale physics
and we can obtain ``bottom-up'' type information about new physics. In this
paper, we consider the precision measurements of the top sector at the LHC by
using black holes. The stringent trigger conditions to confirm the black hole
production vanish almost all of the QCD background, and we can examine the top
quark emitted from black holes very precisely. The error of the top quark mass
and the top Yukawa coupling are drastically reduced, leading to a very accurate
test of the Higgs mechanism. We can directly measure the CKM matrix element
|V_{ts}|, and we will understand the property of the CKM matrix and the origin
of CP-violation deeply. The very precise measurements of such properties in the
SM, enabled by black holes, can become treasures in the quest for TeV-scale
physics because there exists a possibility that TeV-scale physics affects them
and destroys the predictions of the SM. By combining the direct information of
new physics obtained from black holes themselves and the indirect information
obtained from the limitations of the SM, we will be able to identify TeV-scale
physics correctly.


title: Relativistic Treatment of Neutrino Oscillations in Moving Matter

abstract:
  A review on the Lorentz invariant treatment of neutrino spin and flavour
oscillations in moving and polarized matter is presented. Within this approach
it becomes possible to consider neutrino oscillations in arbitrary
electromagnetic fields. It is also shown that neutrino effective potential in
matter can be significantly changed by relativistic motion of matter.


title: Color-Neutral Superconducting Quark Matter

abstract:
  We investigate the consequences of enforcing local color neutrality on the
color superconducting phases of quark matter by utilizing the
Nambu-Jona-Lasinio model supplemented by diquark and the t'Hooft six-fermion
interactions. In neutrino free matter at zero temperature, color neutrality
guarantees that the number densities of u, d, and s quarks in the
Color-Flavor-Locked (CFL) phase will be equal even with physical current quark
masses. Electric charge neutrality follows as a consequence and without the
presence of electrons. In contrast, electric charge neutrality in the less
symmetric 2-flavor superconducting (2SC) phase with ud pairing requires more
electrons than the normal quark phase. The free energy density cost of
enforcing color and electric charge neutrality in the CFL phase is lower than
that in the 2SC phase, which favors the formation of the CFL phase. With
increasing temperature and neutrino content, an unlocking transition occurs
from the CFL phase to the 2SC phase with the order of the transition depending
on the temperature, the quark and lepton number chemical potentials. The
astrophysical implications of this rich structure in the phase diagram,
including estimates of the effects from Goldstone bosons in the CFL phase, are
discussed.


title:
Perturbative and non-perturbative aspects of the non-abelian
  Boltzmann-Langevin equation

abstract:
  We study the Boltzmann-Langevin equation which describes the dynamics of hot
Yang-Mills fields with typical momenta of order of the magnetic screening scale
g^2 T. It is transformed into a path integral and Feynman rules are obtained.
We find that the leading log Langevin equation can be systematically improved
in a well behaved expansion in log(1/g)^-1. The result by Arnold and Yaffe that
the leading log Langevin equation is still valid at next-to-leading-log order
is confirmed. We also confirm their result for the next-to-leading-log damping
coefficient, or color conductivity, which is shown to be gauge fixing
independent for a certain class of gauges. The frequency scale g^2T does not
contribute to this result, but it does contribute, by power counting, to the
transverse gauge field propagator. Going beyond a perturbative expansion we
find 1-loop ultraviolet divergences which cannot be removed by renormalizing
the parameters in the Boltzmann-Langevin equation.


title: Muon transverse polarization in the $K_{l2\gamma}$ decay in SM

abstract:
  The muon transverse polarization in the $K^+ \to \mu^+ \nu \gamma$ process
induced by the electromagnetic final state interaction is calculated in the
framework of Standard Model. It is shown that one loop contributions lead to a
nonvanihing muon transverse polarization. The value of the muon transverse
polarization averaged over the kinematical region of $E_\gamma \geq 20$ MeV is
equal to $5.63 \times 10^{-4}$.


title: Update on very light CP-odd scalar in the Two-Higgs-Doublet Model

abstract:
  In a previous work we have shown that a general two-Higgs-doublet model
(THDM) with a very light CP-odd scalar can be compatible with electroweak
precision data, such as the rho parameter, BR(b --> s gamma), R_b, A_b,
BR(Upsilon --> A gamma), BR(eta --> A gamma), and (g-2) of muon. Prompted by
the recent significant change in the theoretical status of the latter
observable, we comment on the consequences for this model and update the
allowed parameter region. It is found that the presence of a very light scalar
with a mass of 0.2 GeV is still compatible with the new theoretical prediction
of the muon anomalous magnetic moment.


title:
On the Formulation of the Generic Supersymmetric Standard Model (or
  Supersymmetry without R parity)

abstract:
  The generic supersymmetric version of the Standard Model would have the
minimal list of superfields incorporating the Standard Model particles, and a
Lagrangian dictated by the Standard Model gauge symmetries. To be
phenomenologically viable, soft supersymmetry breaking terms have to be
included. In the most popular version of the supersymmetric Standard Model, an
{\it ad hoc} discrete symmetry, called R parity, is added in by hand. While
there has been a lot of various kinds of R-parity violation studies in the
literature, the complete version of supersymmetry without R parity is not
popularly appreciated. In this article, we present a pedagogical review of the
formulation of this generic supersymmetric Standard Model and give a detailed
discussion on the basic conceptual issues involved. Unfortunately, there are
quite some confusing, or even plainly wrong, statements on the issues within
the literature of R-parity violations. We aim at clarifying these issues here.
We will first discuss our formulation, about which readers are urged to read
without bias from previous acquired perspectives on the topic. Based on the
formulation, we will then address the various issues . In relation to
phenomenology, our review here will not go beyond tree-level mass matrices. But
we will give a careful discussion of mass matrices of all the matter fields
involved. Useful expressions for perturbative diagonalizations of the mass
matrices at the phenomenologically interesting limit of corresponds to small
neutrino masses are derived. All these expressions are given in the fully
generic setting, with information on complex phases of parameters retained.
Such expressions have been shown to be useful in the analyses of various
phenomenological features.


title:
Nuclear Data in Oklo and Time-Variability of Fundamental Coupling
  Constants

abstract:
  We re-examined Shlyakhter's analysis of the Sm data in Oklo. With a special
care of minimizing contamination due to the inflow of the isotope after the end
of the reactor activity, we confirmed that his result on the time-variability
of the fine-structure constant, $|\dot{\alpha}/\alpha |\lsim 10^{-17}{\rm
y}^{-1}$, was basically correct. In addition to this upper bound, however, we
obtained another result that indicates a different value of $\alpha$ 2 billion
years ago. We add comments on the recent result from QSO's.


title: Supernova Neutrinos, LSND and MiniBooNE

abstract:
  The unique constraints on neutrino oscillations which can be obtained by
measuring the energy spectrum of supernova $\bar{\nu}_e$'s are first discussed.
The focus is on 4-neutrino mass and mixing models capable of explaining the
LSND evidence of $\bar{\nu}_{\mu}\to \bar{\nu}_e$ oscillations.
  The potential of the Fermilab neutrino detector MiniBooNE to observe
supernova neutrinos is then addressed, and a general description of the
detector is given. As of May, 2002, the MiniBooNE detector is fully
operational.


title: Generalized parton distributions in impact parameter space

abstract:
  We study generalized parton distributions in the impact parameter
representation, including the case of nonzero skewness xi. Using Lorentz
invariance, and expressing parton distributions in terms of impact parameter
dependent wave functions, we investigate in which way they simultaneously
describe longitudinal and transverse structure of a fast moving hadron. We
compare this information with the one in elastic form factors, in ordinary and
in k_T dependent parton distributions.


title: Dual Superconductivity, Effective String Theory, and Regge Trajectories

abstract:
  We show how an effective field theory of long distance QCD, describing a dual
superconductor, can be expressed as an effective string theory of
superconducting vortices. We evaluate the semiclassical expansion of this
effective string theory about a classical rotating string solution in any
spacetime dimension D. We show that, after renormalization, the zero point
energy of the string fluctuations remains finite when the masses of the quarks
on the ends of the strings approach zero. For D = 26 the semiclassical energy
spectrum of the rotating string formally coincides with that of the open string
in classical Bosonic string theory. However, its physical origin is different.
It is a semiclassical spectrum of an effective string theory valid only for
large values of the angular momentum. For D = 4 the first semiclassical
correction adds the constant 1/12 to the classical Regge formula for the
angular momentum of mesons on the leading Regge trajectory. The excited
vibrational modes of the rotating string give rise to daughter Regge
trajectories determining the spectrum of hybrid mesons.


title: Order-v^4 Corrections to S-wave Quarkonium Decay

abstract:
  We compute corrections of relative order v^4 to the rates for the decays of
^1S_0 heavy quarkonium into two photons and into light hadrons and for the
decays of ^3S_1 heavy quarkonium into a lepton pair and into light hadrons. In
particular, we compute the coefficients of the decay operators that have the
same quantum numbers as the heavy quarkonium. We also confirm previous
calculations of the order-v^2 corrections to these rates. We find that the v
expansion converges well for the decays of ^1S_0 heavy quarkonium and for the
decay of ^3S_1 heavy quarkonium into a lepton pair. Large higher-order-in-v
corrections appear in the decay of ^3S_1 heavy quarkonium into light hadrons.
However, we find that the series of coefficients of operators with ^3S_1
quantum numbers, which yields a large correction in order v^2, yields a smaller
correction in order v^4.


title: Signals for Lorentz Violation in Electrodynamics

abstract:
  An investigation is performed of the Lorentz-violating electrodynamics
extracted from the renormalizable sector of the general Lorentz- and
CPT-violating standard-model extension. Among the unconventional properties of
radiation arising from Lorentz violation is birefringence of the vacuum. Limits
on the dispersion of light produced by galactic and extragalactic objects
provide bounds of 3 x 10^{-16} on certain coefficients for Lorentz violation in
the photon sector. The comparative spectral polarimetry of light from
cosmologically distant sources yields stringent constraints of 2 x 10^{-32}.
All remaining coefficients in the photon sector are measurable in
high-sensitivity tests involving cavity-stabilized oscillators. Experimental
configurations in Earth- and space-based laboratories are considered that
involve optical or microwave cavities and that could be implemented using
existing technology.


title: MSSM Higgs sector CP violation at photon colliders: Revisited

abstract:
  We present a comprehensive analysis on the MSSM Higgs sector CP violation at
photon colliders including the chargino contributions as well as the
contributions of other charged particles. The chargino loop contributions can
be important for the would-be CP odd Higgs production at photon colliders.
Polarization asymmetries are indispensable in determining the CP properties of
neutral Higgs bosons.


title: Finite Mixing Angles in the Standard Model

abstract:
  We establish the existence of one-loop finite relations between the Cabibbo
angle and the quark mass ratios, in the Standard Model with one Higgs doublet
and two quark generations. Assuming a simple quark-lepton universality, we use
the recent SNO results to predict the two-flavour mass spectrum of the
neutrinos.


title:
The [1,2] Pad\'e Amplitudes for $\pi\pi$ Scatterings in Chiral
  Perturbation Theory

abstract:
  A detailed analysis to the [1,2] Pad\'e approximation to the $\pi\pi$
scattering 2--loop amplitudes in chiral perturbation theory is made.


title: Anisotropic QCD superfluids

abstract:
  We discuss two instances of anisotropic ordered quantum phases within QCD at
finite baryon densities: (1) Fermionic deconfined three-color QCD matter with a
spin one quark-quark Cooper pair condensate can exhibit distinct quantum i.e.
low-temperature ($T$) behaviors on macroscopic scales which bona fide can be
observed in neutron stars. (2) Bosonic confined two-color QCD matter with a
Bose-Einstein condensate of spin-one baryons can exhibit distinct quantum i.e.
low-$T$ behaviors on macroscopic scales which can bona fide be observed in
numerical lattice experiments.


title: Neutrinos: summarizing the state-of-the-art

abstract:
  I review oscillation solutions to the neutrino anomalies and discuss how to
account for the required pattern of neutrino masses and mixings from first
principles. Unification and low-energy bottom-up approaches are discussed, the
latter open up the possibility of testing neutrino mixing at high energy
colliders, such as the LHC. Large \ne mixing is consistent with Supernova (SN)
astrophysics and may serve to probe galactic SN parameters at Cherenkov
detectors. I discuss the robustness of the atmospheric neutrino oscillation
hypothesis against the presence of Flavor Changing (FC) Non-Standard neutrino
Interactions (NSI), generally expected in models of neutrino mass. Atmospheric
data strongly constrain FC-NSI in the \nm-\nt channel, while solar data can be
explained by FC-NSI in the \ne-\nt channel, or, alternatively, by spin flavor
precession. I illustrate how a neutrino factory offers a unique way to probe or
FC-NSI and argue that a near-site detector is necessary in order to probe for
leptonic mixing and CP violation.


title: Multigap diffraction at CDF

abstract:
  We present a study of $\bar pp$ collisions with a leading antiptoton and a
rapidity gap in addition to that associated with the antiproton. The second gap
is either within the region available to the proton dissociation products,
$\bar p+p\to (\bar p+gap)+X+gap+Y$, or adjacent to the outgoing proton $\bar
p+p\to (\bar p+gap)+X+(gap+p)$. Results are reported for two-gap to one-gap
event ratios and compared with one-gap to no-gap ratios and with theoretical
expectations.


title: Electroweak jet cascading in the decay of superheavy particles

abstract:
  We study decays of superheavy particles $X$ into leptons. We show that they
initiate cascades similar to QCD parton jets, if $m_X\gsim 10^6$ GeV.
Electroweak cascading is studied and the energy spectra of the produced leptons
are calculated in the framework of a broken SU(2) model of weak interactions.
As application, important for the Z-burst model for ultrahigh energy cosmic
rays, we consider decays of superheavy particles coupled on tree-level only to
neutrinos and derive stringent limit for these decays from the observed diffuse
extragalactic $\gamma$-ray flux.


title:
Crystalline Color Superconductivity: Effective Lagrangian and Phonon
  Dispersion Law

abstract:
  The recent study by Bowers and Rajagopal on the possible structures for the
QCD crystalline color superconducting phase favors a cubic structure and allows
for a first discussion of the QCD dynamics in the crystalline phase. The cubic
structure leads to complete breaking of traslation invariance and to three
phonon modes. We discuss the expected form of the effective Lagrangian and the
phonon dispersion laws assuming the proposed crystal structure. Besides the
interest for QCD and the related possible relevance to compact stars these
considerations may become useful to atomic systems exhibiting crystalline
superfluidity.


title: Detection of Supernova Neutrinos by Neutrino-Proton Elastic Scattering

abstract:
  We propose that neutrino-proton elastic scattering, $\nu + p \to \nu + p$,
can be used for the detection of supernova neutrinos in scintillator detectors.
Though the proton recoil kinetic energy spectrum is soft, with $T_p \simeq 2
E_\nu^2/M_p$, and the scintillation light output from slow, heavily ionizing
protons is quenched, the yield above a realistic threshold is nearly as large
as that from $\bar{\nu}_e + p \to e^+ + n$. In addition, the measured proton
spectrum is related to the incident neutrino spectrum, which solves a
long-standing problem of how to separately measure the total energy and
temperature of $\nu_\mu$, $\nu_\tau$, $\bar{\nu}_\mu$, and $\bar{\nu}_\tau$.
The ability to detect this signal would give detectors like KamLAND and
Borexino a crucial and unique role in the quest to detect supernova neutrinos.


title: J/\Psi suppression in an equilibrium hadron gas

abstract:
  A model for $J/\Psi$ suppression at a high energy heavy ion collision is
presented. The main (and the only) reason for the suppression is $J/\Psi$
inelastic scattering within hadron matter. The hadron matter is in the form of
an evolving multi-component point-like non-interacting gas. The estimations of
the sound velocity in the gas and the approximate pattern of cooling caused by
the longitudinal expansion are also presented. It is shown that under such
circumstances and with $J/\Psi$ disintegration in nuclear matter added,
$J/\Psi$ suppression evaluated agrees well with NA38 and NA50 data.
Additionally, some rough estimations of $J/\Psi$ suppression in hadron matter
described in the framework of the excluded volume gas model are given.


title: An Overview of the Sources for Electroweak Baryogenesis

abstract:
  After a short review of electroweak scale baryogenesis, we consider the
dynamics of chiral fermions coupled to a complex scalar field through the
standard Yukawa interaction term at a strongly first order electroweak phase
transition. By performing a systematic gradient expansion we can use this
simple model to study electroweak scale baryogenesis. We show that the dominant
sources for electroweak baryogenesis appear at linear order in the Planck
constant h-bar. We provide explicit expressions for the sources both in the
flow term and in the collision term of the relevant kinetic Boltzmann equation.
Finally, we indicate how the kinetic equation sources appear in the fluid
transport equations used for baryogenesis calculations.


title: Two-gluon form factor of the nucleon and $J/\psi$ photoproduction

abstract:
  We argue that the t-dependence of the two-gluon form factor of the nucleon
should be given by $\Gamma(t)=(1-t/m_{2g}^2)^{-2}$ with $m_{2g}^2\approx 1
GeV^2$. We demonstrate that this form provides a good description of the
t-dependence of the cross section of the elastic photoproduction of
$J/\psi$-mesons between the threshold region of $E_{\gamma}=11 GeV$ (Cornell),
$E_{\gamma}=19 GeV$ (SLAC) and $E_{\gamma}=100 GeV$ (FNAL) including the strong
energy dependence of the t-slope. It is also well matched with the recent HERA
data. The same assumption explains also the t-dependence of $\phi$-meson
electroproduction near threshold at $W=2.3 GeV, Q^2=1.0 GeV^2$.


title: Optical Unification

abstract:
  We discuss string scale unification facilitated by exotic matter with masses
at intermediate scales, between the observable sector supersymmetry breaking
scale and the string scale. We point out a mechanism by which string scale
unification may occur while producing a (lower) virtual unification scale
independent of the location of the intermediate scale and the value of the
string coupling. The apparent unification obtained by extrapolating low energy
gauge couplings is not accidental when this mechanism is invoked; virtual
unification is robust.


title: Supersymmetric Dark Matter and Recent Experimental Constraints

abstract:
  In this talk we discuss the impact of recent experimental information, like
the revised bound from E821 Brookhaven experiment on $g_{\mu}-2$ and light
Higgs boson mass bound from LEP, in delineating regions of the parameters of
the Constrained Minimal Supersymmetric Standard Model which are consistent with
the cosmological data. The effect of these to Dark Matter direct searches is
also discussed.


title: Renormalization flow from UV to IR degrees of freedom

abstract:
  Within the framework of exact renormalization group flow equations, a
scale-dependent transformation of the field variables provides for a continuous
translation of UV to IR degrees of freedom. Using the gauged NJL model as an
example, this translation results in a construction of partial bosonization at
all scales. A fixed-point structure arises which makes it possible to
distinguish between fundamental-particle and bound-state behavior of the scalar
fields.


title:
CP violation in charged Higgs boson decays in the MSSM with complex
  parameters

abstract:
  Supersymmetric loop contributions can lead to different decay rates of H+\to
t\bar b and H-\to b\bar t. We calculate the decay rate asymmetry \delta^CP =
\frac{\Gamma(H+\to t\bar b)-\Gamma(H-\to b\bar t)}{{\Gamma(H+\to t\bar
b)+\Gamma(H-\to b\bar t)} at next-to-leading order in the MSSM with complex
parameters. We analyse the parameter dependence of \delta^CP with emphasis on
the phases of A_t and A_b. It turns out that the most important contribution
comes from the loop with stop, sbottom, and gluino. If this contribution is
present, \delta^CP can go up to 10-15% for tan(beta)~10, and to ~5% for large
values of tan(beta).