title:
The Importance of Being Majorana: Neutrinos versus Charged Fermions in
  Flavor Models

abstract:
  We argue that neutrino flavor parameters may exhibit features that are very
different from those of quarks and charged leptons. Specifically, within the
Froggatt-Nielsen (FN) framework, charged fermion parameters depend on the ratio
between two scales, while for neutrinos a third scale--that of lepton number
breaking--is involved. Consequently, the selection rules for neutrinos may be
different. In particular, if the scale of lepton number breaking is similar to
the scale of horizontal symmetry breaking, neutrinos may become flavor-blind
even if they carry different horizontal charges. This provides an attractive
mechanism for neutrino flavor anarchy.


title:
Physical meaning of two-particle HBT measurements in case of correlated
  emission

abstract:
  It is shown that, in the presence of correlations in particle emission, the
measured HBT radii are related to the correlation range rather than to the size
of the interaction volume. Only in the case of weak correlations the standard
interpretation may be applicable, The earlier discussion [1] of short-range
correlations in configuration space is generalized to include also the
correlations of particle momenta.


title: What is the temperature in heavy ion collisions?

abstract:
  We consider the Tsallis distribution as the source of the apparent slope of
one-particle spectra in heavy-ion collisions and investigate the equation of
state of this special quark matter in the framework of non-extensive
thermodynamics.


title:
From the exclusive photoproduction of heavy quarkonia at HERA to the
  EDDE at TeVatron and LHC

abstract:
  Exclusive photoproduction of heavy quarkonia at HERA is analyzed in the
framework of the Regge-eikonal approach together with the nonrelativistic bound
state formalism. Total and differential cross-sections for the process
$\gamma+p\to (Q\bar{Q})_{1S}+p$ are calculated. The model predicts
cross-sections of Exclusive Double Diffractive Events (EDDE) at TeVatron and
LHC.


title:
Space-Time Evolution of Ultrarelativistic Quantum Dipoles in Quantum
  Electrodynamics

abstract:
  We discuss space-time evolution of ultrarelativistic quantum dipole in QED.
We show that the space-time evolution can be described, in a certain
approximation, by means of a regularized wave function, whose parameters are
determined by the process of the dipole creation by a local current. We derive
using these wave functions the dipole expansion law, that is found to coincide
parametrically in the leading order with the one suggested by Farrar,
Frankfurt,Liu and Strikman.


title:
Can one of three righthanded neutrinos be light enough to produce a
  small LSND effect?

abstract:
  It is shown on the ground of a simple 6\times 6 neutrino mixing model that
one of three conventional sterile (righthanded) neutrinos, if light enough, may
be consistently used for explaining a {\it small} LSND effect. Then, it is
still considerably heavier than the three active (lefhanded) neutrinos, so that
a kind of {\it soft} seesaw mechanism can work. The usual condition that the
Majorana lefthanded component of the overall 6\times 6 neutrino mass matrix
ought to vanish, {\it implies} the smallness of active-neutrino masses versus
sterile-neutrino masses, when three mixing angles between both sorts of
neutrinos are small. In the presented model, the mass spectrum of active
neutrinos comes out roughly degenerate, lying in the range (5 - 7.5)\times
10^{-2} eV, {\it if} there is a {\it small} LSND effect with the amplitude of
the order 10^{-3} and with the mass-squared splitting \sim 1 eV^2.


title:
Determining tan(beta) in \tau\tau Fusion to SUSY Higgs Bosons at a
  Photon Collider

abstract:
  We investigate \tau\tau fusion to light h and heavy H and A Higgs bosons in
the Minimal Supersymmetric Standard Model (MSSM) at a photon collider as a
promising channel for measuring large values of tan(beta). For standard design
parameters of a photon collider an error \Delta tan(beta) \sim 1, uniformly for
tan(beta) \gsim 10, may be expected, improving on complementary measurements at
the LHC and e+e- linear colliders.


title: Recursive numerical calculus of one-loop tensor integrals

abstract:
  A numerical approach to compute tensor integrals in one-loop calculations is
presented. The algorithm is based on a recursion relation which allows to
express high rank tensor integrals as a function of lower rank ones. At each
level of iteration only inverse square roots of Gram determinants appear. For
the phase-space regions where Gram determinants are so small that numerical
problems are expected, we give general prescriptions on how to construct
reliable approximations to the exact result without performing Taylor
expansions. Working in 4+epsilon dimensions does not require an analytic
separation of ultraviolet and infrared/collinear divergences, and, apart from
trivial integrals that we compute explicitly, no additional ones besides the
standard set of scalar one-loop integrals are needed.


title: Deeply Virtual Neutrino Scattering (DVNS)

abstract:
  We introduce the study of neutrino scattering off protons in the deeply
virtual kinematics, which describes under a unified formalism elastic and deep
inelastic neutrino scattering. A real final state photon and a recoiling
nucleon are detected in the few GeV ($|t|\sim 0.2-5$ GeV) region of momentum
transfer. This is performed via an extension of the notion of deeply virtual
Compton scattering, or DVCS, to the case of a neutral current exchange. The
relevance of this process and of other similar exclusive processes for the
study of neutrino interactions in neutrino factories for GeV neutrinos is
pointed out.


title: Bosonic Operator Methods for the Quark Model

abstract:
  Quark model matrix elements can be computed using bosonic operators and the
holomorphic representation for the harmonic oscillator. The technique is
illustrated for normal and exotic baryons for an arbitrary number of colors.
The computations are much simpler than those using conventional quark model
wavefunctions.


title: Heavy and Light Pentaquark Chiral Lagrangian

abstract:
  Using the SU(3) flavor symmetry, we construct the chiral Lagrangians for the
light and heavy pentaquarks. The correction from the nonzero quark is taken
into account perturbatively. We derive the Gell-Mann$-$Okubo type relations for
various pentaquark multiplet masses and Coleman-Glashow relations for
anti-sextet heavy pentaquark magnetic moments. We study possible decays of
pentaquarks into conventional hadrons. We also study the interactions between
and within various pentaquark multiplets and derive their coupling constants in
the symmetry limit. Possible kinematically allowed pionic decay modes are
pointed out.


title: Neutrino Masses and GUT Baryogenesis

abstract:
  We reconsider the GUT-baryogenesis mechanism for generating the baryon
asymmetry of the Universe. The baryon asymmetry is produced by the out of
equilibrium decay of coloured Higgs bosons at the GUT scale, conserving B-L. If
neutrinos are Majorana particles, lepton number violating interactions erase
the lepton number excess, but part of the baryon asymmetry may be preserved,
provided those interactions are not in thermal equilibrium when the sphaleron
processes become effective, at $T \sim 10^{12}~ GeV$. We analyse whether this
mechanism for baryogenesis is feasible in a variety of GUT models of fermion
masses proposed in the literature, based on horizontal symmetries.


title:
Relativistic Nucleus-Nucleus Collisions: A Connection between the
  Strangeness-Maximum at $\sqrt{s} \approx$ 7 GeV and the QCD Critical Endpoint
  from Lattice Studies

abstract:
  A steep maximum occurs in the Wroblewski ratio between strange and
non-strange quarks created in central nucleus-nucleus collisions, of about
A=200, at the lower SPS energy $\sqrt{s} \approx$ 7 GeV. By analyzing hadronic
multiplicities within the grand canonical statistical hadronization model this
maximum is shown to occur at a baryochemical potential of about 450 MeV. In
comparison, recent QCD lattice calculations at finite baryochemical potential
suggest a steep maximum of the light quark susceptibility, to occur at similar
$\mu_B$, indicative of "critical fluctuation" expected to occur at or near the
QCD critical endpoint. This endpoint hat not been firmly pinned down but should
occur in the 300 MeV $ < \mu_B^c<700$ MeV interval. It is argued that central
collisions within the low SPS energy range should exhibit a turning point
between compression/heating, and expansion/cooling at energy density,
temperature and $\mu_B$ close to the suspected critical point. Whereas from top
SPS to RHIC energy the primordial dynamics create a turning point far above in
$\epsilon$ and T, and far below in $\mu_B$. And at lower AGS energies the
dynamical trajectory stays below the phase boundary. Thus, the observed sharp
strangeness maximum might coincide with the critical $\sqrt{s}$ at which the
dynamics settles at, or near the QCD endpoint.


title: Pentaquark and diquark-diquark clustering: a QCD sum rule approach

abstract:
  In this work we study the Theta(1540) in the framework of QCD sum rules based
on (ud)^2\bar{s} diquark clustering as suggested by Jaffe and Wilczek. Within
errors, the mass of the pentaquark is compatible with the experimentally
measured value. The mass difference between the Theta and the pentaquark with
the quantum numbers of the nucleon amounts to 70 MeV, consistent with the
interpretation of the N(1440) as a pentaquark.


title: The rare decay KL -> pi0 mu+ mu- within the SM

abstract:
  We present an updated analysis of the rare decay
$K_{L}\to\pi^{0}\mu^{+}\mu^{-}$ within the Standard Model. In particular, we
present the first complete calculation of the two-photon CP-conserving
amplitude within Chiral Perturbation Theory, at the lowest non-trivial order.
Our results confirm previous findings that the CP-conserving contribution to
the decay rate cannot be neglected. By means of an explicit two-loop
calculation, we show that this contribution can be estimated with sufficient
accuracy compared to the CP-violating terms. We predict
$\cB(K_L\to\pi^0\mu^+\mu^-)_{\rm SM}=(1.5\pm0.3)\times10^{-11}$, with
approximately equal contributions from the CP-conserving component, the
indirect-CP-violating term, and the interesting direct-CP-violating amplitude.
The error of this prediction is mainly of parametric nature and could be
substantially reduced with better data on the $K_{S}\to\pi^{0}\ell^{+}\ell^{-}$
modes. The Standard Model predictions for various differential distributions
and the sensitivity to possible new-physics effects are also briefly discussed.


title:
Electroweak-scale inflation, inflaton-Higgs mixing and the scalar
  spectral index

abstract:
  We construct a phenomenological model of electroweak-scale inflation that is
in accordance with recent cosmic microwave background observations by WMAP,
while setting the stage for a zero-temperature electroweak transition as
assumed in recent models of baryogenesis. We find that the scalar spectral
index especially poses tight constraints for low-scale inflation models. The
inflaton-Higgs coupling leads to substantial mixing of the scalar degrees of
freedom. Two types of scalar particles emerge with decay widths similar to that
of the Standard Model Higgs particle.


title: Majorana Neutrino Masses from Anomalous U(1) Symmetries

abstract:
  We explore the possibility of interpreting the solar and atmospheric neutrino
data within the context of the Minimal Supersymmetric Standard Model augmented
by a single U(1) anomalous family symmetry spontaneously broken by non-zero
vacuum expectation values of a pair of singlet fields. The symmetry retains a
dimension-five operator which provides Majorana masses for left-handed neutrino
states. Assuming symmetric lepton mass matrices, the model predicts inverse
hierarchical neutrino mass spectrum, theta_{13}=0 and large mixing while at the
same time it provides acceptable mass matrices for the charged fermions.


title: Measuring New-Physics Parameters in B Penguin Decays

abstract:
  We examine new-physics (NP) effects in B decays with large b -> s penguin
amplitudes. Decays involving b -> d penguins are assumed to be unaffected. We
consider a model-independent parametrization of such NP. We argue that NP
strong phases are negligible relative to those of the standard model. This
allows us to describe the NP effects in terms of a small number of effective
amplitudes A_NP^q (q=u,d,s,c) and corresponding weak phases Phi_q. We then
consider pairs of neutral B decays which are related by flavour SU(3) in the
standard model. One receives a large b -> s penguin component and has a NP
contribution; the other has a b -> d penguin amplitude and is unaffected by NP.
The time-dependent measurement of these two decays allows the {\it measurement}
of the NP parameters A_NP^q and Phi_q. The knowledge of these parameters allows
us to rule out many NP models and thus partially identify the new physics.


title: Baryon Axial Charge in a Finite Volume

abstract:
  We compute finite-volume corrections to nucleon matrix elements of the
axial-vector current. We show that knowledge of this finite-volume dependence
--as well as that of the nucleon mass-- obtained using lattice QCD will allow a
clean determination of the chiral-limit values of the nucleon and
Delta-resonance axial-vector couplings.


title: Signal of the pion string at high-energy collisions

abstract:
  We study the possible signals of a pion string associated with the QCD chiral
phase transition in LHC Pb - Pb collision at energy $ \sqrt{s}=5.5$ TeV. In
terms of the Kibble-Zurek mechanism we discuss the production and evolution of
the pion string. The pion string is not topologically stable, it decays into
neutral pions and sigma mesons which in turn decay into pions. Our results show
that all the neutral pions from the pion string are distributed at the low
momentum and the ratio of neutral to charged pions from the pion string
violates the isospin symmetry. For the momentum spectra of the total pions, the
signal from the sigma particle decay which is from the pion string will be
affected by the large decay width of the sigma significantly.


title:
Enhancement of Critical Slowing Down in Chiral Phase Transition --
  Langevin Dynamics Approach --

abstract:
  We derive the linear Langevin equation that describes the behavior of the
fluctuations of the order parameter of the chiral phase transition above the
critical temperature by applying the projection operator method to the
Nambu-Jona-Lasinio model at finite temperature and density. The Langevin
equation relaxes exhibiting oscillation, reveals thermalization and converges
to the equilibrium state consistent with the mean-field approximation as time
goes on. With the help of this Langevin equation, we further investigate the
relaxation of the critical fluctuations. The relaxation time of the critical
fluctuations increases at speed as the temperature approaches toward the
critical temperature because of the critical slowing down. The critical slowing
down is enhanced as the chemical potential increases because of the Pauli
blocking. Furthermore, we find another enhancement of the critical slowing down
around the tricritical point.


title:
A solution to the baryon and dark-matter coincidence puzzle in a
  $\tilde{N}$ dominated early universe

abstract:
  If a bosonic partner of a right-handed neutrino dominates the early universe
sufficiently before its decay, important ingredients in the present universe
are related to physics of the right-handed neutrino sector. In particular, we
find that the ratio of the baryon to the dark-matter densities is given only by
low-energy parameters such as a neutrino mass and a gravitino mass if the
reheating temperature of inflation is much higher than $10^{12}$ GeV. Here, the
gravitino is assumed to be the lightest supersymmetric particle and the
dominant component of the dark matter. The observed ratio,
$\Omega_{B}/\Omega_{DM} \simeq 0.21\pm 0.04$, suggests the mass of the
gravitino to be in the range of $\cal O$(10) MeV provided the CP violating
phase is of the order 1.


title: MSLED: A Minimal Supersymmetric Large Extra Dimensions Scenario

abstract:
  We propose a framework for the low-energy realization of supersymmetry which
is very predictive, but differs radically in its phenomenological implications
from the supersymmetric Standard Model (minimal or otherwise). The proposal
consists of a supersymmetric version of the Large-Extra-Dimensions scenario,
with the Standard Model living on a 3-brane, coupled to a bulk sector
consisting of six-dimensional supergravity. This picture is motivated by a
promising recent attempt (hep-th/0304256) to naturally understand the observed
dark energy density, and this connection with dark energy prevents making the
extra dimensions smaller than of order 5 $\mu$m. The resulting inability to
change this size makes the model very predictive, and easily falsifiable within
the near future. Being supersymmetric, it may plausibly be embedded into a more
fundamental theory such as string theory, in which case an additional 4 compact
dimensions may also be present having inverse radii at the TeV scale or higher.
The model is close to, but consistent with, current experimental constraints.
We outline possible phenomenological implications for particle physics (both at
accelerators and elsewhere), for precision tests of gravity, for astrophysics
and for cosmology.


title: Rare Kaon Decays Revisited

abstract:
  We present an updated discussion of $K\ra\pi \bar{l} l$ decays in a combined
framework of chiral perturbation theory and Large--$N_c$ QCD, which assumes the
dominance of a minimal narrow resonance structure in the invariant mass
dependence of the $ \bar{l} l$ pair. The proposed picture reproduces very well,
both the experimental $K^+\ra\pi^+ e^+ e^-$ decay rate and the invariant $e^+
e^-$ mass spectrum. The predicted Br$(K_S\ra\pi^0 e^+ e^-)$ is, within errors,
consistent with the recently reported result from the NA48 collaboration.
Predictions for the $K\ra\pi \mu^{+}\mu^{-}$ modes are also obtained. We find
that the resulting interference between the {\it direct} and {\it indirect}
CP--violation amplitudes in $K_L\ra\pi^0 e^+ e^-$ is constructive.


title: Strong CP breaking and quark-antiquark repulsion in QCD, at finite theta

abstract:
  This work is devoted to the study of the CP-breaking dynamics in QCD, at
finite theta-angle. By working in the semi-classical limit, in which the
topology of the vacuum is clustered around instantons and anti-instantons, we
show that quantum fluctuations of the theta-vacuum generate an effective
flavor-dependent repulsion between matter and anti-matter, inside hadrons. As a
consequence, during the tunneling between the degenerate vacua, quarks and
anti-quarks in the neutron migrate in opposite directions, giving rise to an
oscillating electric dipole moment. We discuss a possible phenomenological
implication of this effect.


title:
Form factor decomposition of generalized parton distributions at leading
  twist

abstract:
  We extend the counting of generalized form factors presented in PRD63(2000)
by Ji and Lebed to the axial vector and the tensor operator at twist-2 level.
Following this, a parameterization of all higher moments in x of the tensor
(helicity flip) operator is given in terms of generalized form factors.


title:
Searching for family-number conserving neutral gauge bosons from extra
  dimensions

abstract:
  Previous studies have shown how the three generations of the Standard Model
fermions can arise from a single generation in more than four dimensions, and
how off-diagonal neutral couplings arise for gauge-boson Kaluza-Klein
recurrences. These couplings conserve family number in the leading
approximation. While an existing example, built on a spherical geometry,
suggests a high compactification scale, we conjecture that the overall
structure is generic, and work out possible signatures at colliders, compatible
with rare decays data.


title: A model for the spacetime evolution of heavy-ion collisions at RHIC

abstract:
  We investigate the space-time evolution of ultrarelativistic Au-Au collisions
at full RHIC energy using a schematic model of the expansion. Assuming a
thermally equilibrated system, we can adjust the essential scale parameters of
this model such that the measured transverse momentum spectra and Hanbury-Brown
Twiss (HBT) correlation parameters are well described. We find that the
experimental data strongly constrain the dynamics of the evolution of the
emission source although hadronic observables for the most part reflect the
final breakup of the system.


title: BRANECODE: A Program for Simulations of Braneworld Dynamics

abstract:
  We describe an algorithm and a C++ implementation that we have written and
made available for calculating the fully nonlinear evolution of 5D braneworld
models with scalar fields. Bulk fields allow for the stabilization of the extra
space. However, they complicate the dynamics of the system, so that analytic
calculations (performed within an effective 4D theory) are typically only
reliable close to stabilized configurations or when the evolution of the extra
space is negligible. In the general case, a numerical study of the 5D equations
is necessary, and the algorithm and code we describe are the first ones
designed for this task. The program and its full documentation are available on
the Web at http://www.cita.utoronto.ca/~jmartin/BRANECODE/. In this paper we
provide a brief overview of what the program does and how to use it.


title: Unity of CP and T Violation in Neutrino Oscillations

abstract:
  In a previous work a simultaneous P- CP[P] and P- T[P] bi-probability plot
was proposed as a useful tool for unified graphical description of CP and T
violation in neutrino oscillation. The ``baseball diamond'' structure of the
plot is understood as a consequence of the approximate CP-CP and the T-CP
relations obeyed by the oscillation probabilities. In this paper, we make a
step forward toward deeper understanding of the unified graphical
representation by showing that these two relations are identical in its
content, suggesting a truly unifying view of CP and T violation in neutrino
oscillations. We suspect that the unity reflects the underlying CPT theorem. We
also present calculation of corrections to the CP-CP and the T-CP relations to
leading order in Delta m^2_{21} / Delta m^2_{31} and s^2_{13}.


title: Perturbative Heavy Quark Fragmentation Function through O(alpha_s^2)

abstract:
  We derive the initial condition for the perturbative fragmentation function
of a heavy quark through order O(alpha_s^2) in the MS-bar scheme. This initial
condition is useful for computing heavy quark (or lepton, in case of QED)
energy distributions from calculations with massless partons. In addition, the
initial condition at O(alpha_s^2) can be used to resum collinear logarithms
ln(Q^2/m^2) in heavy quark energy spectrum with next-to-next-to-leading
logarithmic accuracy by solving the DGLAP equation.


title:
Prediction of Narrow $J^\pi=1/2^+$, $3/2^+$, and $3/2^-$ states of
  $\Theta_+$ in a Quark model with Antisymmetrized Molecular Dynamics

abstract:
  The exotic baryon $\Theta^+(uudd\bar{s})$ is studied with microscopic
calculations in a quark model by using a method of antisymmetrized molecular
dynamics. We predict that the lowest even state is $J^\pi=1/2^+(I=0)$ or
$J^\pi=3/2^+(I=0)$, and the lowest odd state is $J^\pi=3/2^-(I=1)$. They nearly
degenerate in the $uudd\bar{s}$ system. We discuss $K^+n$ decay widths and
estimate them to be $\Gamma< 7$ for the $J^\pi=\{1/2^+,3/2^+\}$, and $\Gamma<1$
MeV for the $J^\pi=3/2^-$ state.


title: Nuclear exclusive vector meson photoproduction

abstract:
  We calculate the nuclear cross section for vector meson exclusive
photoproduction within the QCD color dipole picture and in the Regge approach.
For the former approach, we have considered the phenomenological saturation
model, whereas for the latter we use a model based on the dipole Pomeron
framework. Theoretical estimates for scattering on both light and heavy nuclei
are given for a large range on energy.


title: More on deviation from bi-maximal neutrino mixing

abstract:
  We study the case of $U^T_l$ presenting the exact bi-maximal mixing form with
$U_\nu$ inducing the deviation from the bi-maximal mixing in the final form of
the Pontecorvo-Maki-Nakagawa-Sakata neutrino mixing, $U_{PMNS}=U^T_l U_\nu$. We
will show that such possibility will lead to a democratic texture for the
charged lepton mass matrix and to a neutrino mass matrix with four null
entries.


title: Spin effects in diffractive $ Q \bar Q$ production at BNL eRHIC

abstract:
  We discuss quark-antiquark leptoproduction within a QCD two-gluon exchange
model at small $x$. The double spin asymmetries for longitudinally polarized
leptons and transversely polarized protons in diffractive $Q \bar Q$ production
are analysed at eRHIC energies. The predicted $A_{lT}$ asymmetry is large and
can be used to obtain information on the polarized generalized gluon
distributions in the proton.


title:
Alternative Approach to $B^- \to \eta^{\prime} K^-$ Branching Ratio
  Calculation

abstract:
  Since the calculation of $BR(B^- \to \eta^{\prime} K^-)$ in the framework of
QCD improved factorization method, developed by Beneke et al., leads to
numerical values much below the experimental data, we include two different
contributions, in an alternative way. First, we find out that the spectator
hard-scattering mechanism increases the $BR$ value with almost 50%, but the
predictions depend on the combined singularities in the amplitude convolution.
Secondly, by adding SUSY contributions to the Wilson coefficients, we come to a
$BR$ depending on three parameters, whose values are constrained by the
experimental data.


title: $B\to K\pi$ Decays with $1/m_b$ Corrections in $QCD$ Factorization

abstract:
  It is commonly believed that a careful investigation of the subleading terms
is crucial for a better understanding of the $QCD$ factorization in charmless B
decays. In this work the penguin-dominated $B\to K\pi$ decays are discussed
systematically, including the subleading corrections in $1/m_b$ due to soft and
hard gluons, besides the annihilation contributions. Soft-gluon effects for all
the relevant 4-quark effective operators are calculated within the framework of
the light-cone QCD sum rules (LCSR). Our observation is that such soft and hard
corrections are less important than the annihilation effects, enhancing only
the branching ratios by a few percent; the resultant increase in the branching
ratios due to the overall ${\cal O}(1/m_b)$ effects is between about $(22-27)%$
of the QCD factorization results with the ${\cal O}(\alpha_s)$ corrections, as
the weak phase $\gamma (=\textmd{Im}V_{ub}^*)$ ranges from $40^0$ to $80^0$.
Impacts of the involved uncertainties are discussed in some details.


title: $\pi K$ Scattering in Three Flavour ChPT

abstract:
  We present the scattering lengths for the $\pi K$ processes in the three
flavour Chiral Perturbation Theory (ChPT) framework at next-to-next-to-leading
order (NNLO). The calculation has been performed analytically but we only
include analytical results for the dependence on the low-energy constants
(LECs) at NNLO due to the size of the expressions. These results, together with
resonance estimates of the NNLO LECs are used to obtain constraints on the
Zweig rule suppressed LECs at NLO, $L_4^r$ and $L_6^r$. Contrary to
expectations from NLO order calculations we find them to be compatible with
zero. We do a preliminary study of combining the results from $\pi\pi$
scattering, $\pi K$ scattering and the scalar form-factors and find only a
marginal compatibility with all experimental/dispersive input data.


title:
Decoupling supernova and neutrino oscillation physics with LAr TPC
  detectors

abstract:
  Core collapse supernovae are a huge source of all flavor neutrinos. The
flavor composition, energy spectrum and time structure of the neutrino burst
from a galactic supernova can provide information about the explosion mechanism
and the mechanisms of proto neutron star cooling. Such data can also give
information about the intrinsic properties of the neutrino such as flavor
oscillations. One important question is to understand to which extend can the
supernova and the neutrino physics be decoupled in the observation of a single
supernova. In this paper we discuss the possibility to probe the neutrino
mixing angle \th13 and the type of mass hierarchy from the detection of
supernova neutrinos with a liquid argon TPC detector. Moreover, describing the
supernova neutrino emission by a set of five parameters (average energy of the
different neutrino flavors, their relative luminosity and the total supernova
binding energy), we quantitatively study how it is possible to constrain these
parameters. A characteristic feature of the liquid argon TPC is the
accessibility to four independent detection channels ((1) elastic scattering
off electrons, (2) charged neutrino and (3) antineutrino and (4) neutral
currents on argon nuclei) which have different sensitivities to
electron-neutrino, anti-electron-neutrino and other neutrino flavors (muon and
tau (anti)neutrinos). This allows to over-constrain the five supernova and the
flavor mixing parameters and to some extent disentangle neutrino from supernova
physics.


title:
B -> X_s gamma gamma and B_s -> gamma gamma in supersymmetry with broken
  R-parity

abstract:
  We examine the effects of R-parity violating (RPV) supersymmetry on the
two-photon B decays B -> X_s gamma gamma and B_s -> gamma gamma. We find that,
although there are many one-loop RPV diagrams that can contribute to these
two-photon B decays, the RPV effect is dominated by a single diagram. This
diagram, named here lambda-irreducible, has a distinct topology which is
irrelevant for the b -> s gamma amplitude at one-loop and has thus a negligible
effect on the one-photon decay B -> X_s gamma. We show that the
lambda-irreducible RPV diagram can give BR(B_s -> gamma gamma) ~ 5*10^(-6) and
BR(B -> X_s gamma gamma) ~ 6*10^(-7), which is about 16 and 5 times larger than
the SM values, respectively. Although the enhancement to the decay width of B
-> X_s gamma gamma is not that dramatic, we find that the energy distribution
of the two photons is appreciably different from the SM, due to new threshold
effects caused by the distinct topology of the RPV lambda-irreducible diagram.
Moreover, this diagram significantly changes the forward-backward asymmetry
with respect to the softer photon in B -> X_s gamma gamma. Thus, the RPV effect
in B -> X_s gamma gamma can be discerned using these observables.


title:
Production of gluon jets in pp collisions by double pomeron exchange in
  the Landshoff-Nachtmann model

abstract:
  Using the Landshoff-Nachtmann two-gluon exchange model of the pomeron, the
double pomeron exchange contribution to production of gluon pairs in the
central region of rapidity is calculated. The results are compared with those
for production of quark-antiquark pairs.


title: Conditions for a Successful Right-Handed Majorana Sneutrino Curvaton

abstract:
  We consider the conditions which must be satisfied for a Majorana RH
sneutrino, a massive right-handed (RH) sneutrino associated with the see-saw
mechanism of Majorana neutrino masses, to play the role of the curvaton.
Planck-scale suppressed non-renormalizable terms in the RH neutrino
superpotential must be eliminated to a high order if the RH sneutrino curvaton
is to dominate the energy density before it decays, which can be achieved via
an R-symmetry which is broken to R-parity by the Giudice-Maseiro mechanism. In
order to satisfy the thermalization constraint, one RH neutrino mass eigenstate
must have small Yukawa couplings to the Higgs and lepton doublets,
corresponding to a lightest neutrino mass m_{nu_{1}} < 10^{-3} eV. A
time-dependent lepton asymmetry will be induced in the RH sneutrino condensate
by the Affleck-Dine mechanism driven by SUSY breaking B-terms associated with
the RH neutrino masses. Requiring that the resulting baryon asymmetry and
isocurvature perturbations are acceptably small imposes an upper bound on the
RH neutrino mass. We show that a scenario consistent with all constraints is
obtained for a RH neutrino mass in the range 10^{2} - 10^{4} GeV when the RH
sneutrino decay temperature is greater than 100 GeV and lightest neutrino mass
m_{nu_{1}} approx 10^{-3} GeV. Larger RH neutrino masses are possible for
smaller m_{nu_{1}}. The resulting scenario is generally consistent with a
solution of the cosmic string problem of D-term inflation.


title: Double parton correlations versus factorized distributions

abstract:
  Using the generalized Lipatov-Altarelli-Parisi-Dokshitzer equations for the
two-parton distribution functions we show numerically that the dynamical
correlations contribute to these functions quite a lot in comparison with the
factorized components. At the scale of CDF hard process ($\sim 5$ GeV) this
contribution to the double gluon-gluon distribution is nearly 10% and increases
right up to 30% at the LHC scale ($\sim 100$ GeV) for the longitudinal momentum
fractions $x \leq 0.1$ accessible to these measurements. For the finite
longitudinal momentum fractions $x \sim 0.2 \div 0.4$ the correlations are
large right up to 90% in accordance with the predicted QCD asymptotic
behaviour.


title:
Production of Pentaquark States in pp Collisions within the
  Microcanonical Ensemble

abstract:
  The microcanonical statistical approach is applied to study the production of
pentaquark states in pp collisions. We predict the average multiplicity and
average transverse momentum of Theta^{+}(1540) and Xi(1860) and their
antiparticles at different energies.


title:
Particle production in a strong, slowly-varying magnetic field with an
  application to astrophysics

abstract:
  In this work I studied the production of particles (electron-positron pairs
and photons) in the presence of overcritic ($\gg 4.4\cdot 10^{13}
\text{gauss}$) slowly varying magnetic fields. The calculations are performed
in the framework of QED in the presence of external not quantized
electromagnetic fields by means of the adiabatic perturbation theory. Also,
since such strong magnetic fields may be present near astrophysical compact
objects where gamma-ray bursts (GRB) are thought to be generated, I tried to
reproduce theoretically some features of the GRB energy spectra such as the low
energy ($\lesssim 0.1 \text{MeV}$) behaviour. Also, having in mind this
astrophysical scenario, I took into account the effects of a weak and of a
strong gravitational field on the production probabilities previously
calculated in the flat Minkowski spacetime.


title:
Transverse momentum distribution of Upsilon production in hadronic
  collisions

abstract:
  We calculate the transverse momentum p_T distribution for production of the
Upsilon states in hadronic reactions. For small $p_T (\leq M_\Upsilon)$, we
resum to all orders in the strong coupling alpha_s the process-independent
large logarithmic contributions that arise from initial-state gluon showers. We
demonstrate that the p_T distribution at low p_T is dominated by the region of
small impact parameter b and that it may be computed reliably in perturbation
theory. We express the cross section at large p_T by the alpha_s^3 lowest-order
non-vanishing perturbative contribution. Our results are consistent with data
from the Fermilab Tevatron collider.


title: Neutrinoless double beta decay in SO(10) inspired seesaw models

abstract:
  By requiring the lower limit for the lightest right-handed neutrino mass,
obtained in the baryogenesis from leptogenesis scenario, and a Dirac neutrino
mass matrix similar to the up-quark mass matrix we predict small values for the
$\nu_e$ mass and for the matrix element $m_{ee}$ responsible of the
neutrinoless double beta decay, $m_{\nu_e}$ around $5\cdot10^{-3}$ eV and
$m_{ee}$ smaller than $ 10^{-3}$ eV, respectively. The allowed range for the
mass of the heaviest right-handed neutrino is centered around the value of the
scale of B - L breaking in the SO(10) gauge theory with Pati-Salam intermediate
symmetry.


title: Complete Analysis of Baryon Magnetic Moments in 1/N_c

abstract:
  We generate a complete basis of magnetic moment operators for the N_c = 3
ground-state baryons in the 1/N_c expansion, and compute and tabulate all
associated matrix elements. We then compare to previous results derived in the
literature and predict additional relations among baryon magnetic moments
holding to subleading order in 1/N_c and flavor SU(3) breaking. Finally, we
predict all unknown diagonal and transition magnetic moments to <= 0.15 mu_N
accuracy, and suggest possible experimental measurements to improve the
analysis even further.


title:
Production of the X(3872) in B Meson Decay by the Coalescence of Charm
  Mesons

abstract:
  If the recently-discovered charmonium state X(3872) is a loosely-bound S-wave
molecule of the charm mesons \bar D^0 D^{*0} or \bar D^{*0} D^0, it can be
produced in B meson decay by the coalescence of charm mesons. If this
coalescence mechanism dominates, the ratio of the differential rate for B^+ \to
\bar D^0 D^{*0} K^+ near the \bar D^0 D^{*0} threshold and the rate for B^+ \to
X K^+ is a function of the \bar D^0 D^{*0} invariant mass and hadron masses
only. The identification of the X(3872) as a \bar D^0 D^{*0}/\bar D^{*0} D^0
molecule can be confirmed by observing an enhancement in the \bar D^0 D^{*0}
invariant mass distribution near the threshold. An estimate of the branching
fraction for B^+ \to X K^+ is consistent with observations if X has quantum
numbers J^{PC} = 1^{++} and if J/\psi \pi^+ \pi^- is one of its major decay
modes.


title: Neutralino pair production at CERN LHC

abstract:
  We consider the production of neutralino pairs $\tchi^0_i\tchi^0_j$ at a high
energy hadron collider, putting a special emphasis on the case where one of
them is the lightest neutralino $\tchi^0_1$, possibly constituting the main
Dark Matter component. At tree level, the only relevant subprocess is $q\bar
q\to \tchi^0_i\tchi^0_j$, while the subprocess $gg\to \tchi^0_i\tchi^0_j$ first
appears at the one loop level. Explicit expressions for the $q\bar q$-helicity
amplitudes are presented, including the tree level contributions and the
leading-log one loop radiative corrections. For the one-loop $ gg\to
\tchi^0_i\tchi^0_j$ process, a numerical code named PLATONggnn is released,
allowing the computation of $d\sigma /d \that$ in any MSSM model with real soft
breaking parameters. It turns out that acceptable MSSM benchmark models exist
for which the $q\bar q $ and the gluonic contributions may give comparable
effects at LHC, due to the enhanced gluonic structure functions at low
fractional momenta. Depending on the values of the MSSM parameters, we find
that the LHC neutralino pair production may provide sensitive tests of SUSY
models generating neutralino Dark Matter.


title: Pion Form Factor in the $k_T$ Factorization Formalism

abstract:
  Based on the light-cone (LC) framework and the $k_T$ factorization formalism,
the transverse momentum effects and the different helicity components'
contributions to the pion form factor $F_{\pi}(Q^2)$ are recalculated. In
particular, the contribution to the pion form factor from the higher helicity
components ($\lambda_1+\lambda_2=\pm 1$), which come from the spin-space Wigner
rotation, are analyzed in the soft and hard energy regions respectively. Our
results show that the right power behavior of the hard contribution from the
higher helicity components can only be obtained by fully keeping the $k_T$
dependence in the hard amplitude, and that the $k_T$ dependence in LC wave
function affects the hard and soft contributions substantially. As an example,
we employ a model LC wave function to calculate the pion form factor and then
compare the numerical predictions with the experimental data. It is shown that
the soft contribution is less important at the intermediate energy region.


title: Resummation in Hot Field Theories

abstract:
  There has been significant progress in our understanding of
finite-temperature field theory over the past decade. In this paper, we review
the progress in perturbative thermal field theory focusing on thermodynamic
quantities. We first discuss the breakdown of naive perturbation theory at
finite temperature and the need for an effective expansion that resums an
infinite class of diagrams in the perturbative expansion. This effective
expansion which is due to Braaten and Pisarski, can be used to systematically
calculate various static and dynamical quantities as a weak-coupling expansion
in powers of g. However, it turns that the weak-coupling expansion for
thermodynamic quantities are useless unless the coupling constant is very
small. We critically discuss various ways of reorganizing the perturbative
series for thermal field theories in order to improve its convergence. These
include screened perturbation theory (SPT), hard-thermal-loop perturbation
theory (HTLPT), the Phi-derivable approach, dimensionally reduced (DR) SPT, and
the DR Phi-derivable approach.


title: Precision Electroweak Tests of the Standard Model

abstract:
  The study of electron-positron collisions at LEP, together with additional
measurements from other experiments, in particular those at SLC and at the
Tevatron, has allowed for tests of the electroweak Standard Model with
unprecedented accuracy. We review the results of the electroweak precision
tests and their implications on the determination of the Standard Model
parameters, in particular of the Higgs boson mass, and comment on the
constraints for possible new physics effects.


title:
Chiral Bosonization of U_A(1)-currents and the Energy-Momentum Tensor in
  Quantum Chromodynamics

abstract:
  Recently the new interest arised (hep-ph/0403139) to the chiral coefficients
$L_{11}, L_{12}, L_{13}$ in the low-energy ChPT lagrangian describing the
pseudoscalar meson coupling to gravity and/or light singlet dilatons. In 90ties
we estimated these coefficients within the Chiral and Conformal Bosonization
Model but published the results in the journal not easily accessible for the
physics community. We put now our old paper to the E-archives.


title:
LHC Signatures of Resonant CP Violation in a Minimal Supersymmetric
  Higgs Sector

abstract:
  We present the general formalism for studying CP-violating phenomena in the
production, mixing and decay of a coupled system of CP-violating neutral Higgs
bosons at high-energy colliders. Considering the Minimal Supersymmetric
Standard Model (MSSM) Higgs sector in which CP violation is radiatively induced
by phases in the soft supersymmetry-breaking third-generation trilinear squark
couplings and gaugino masses, we apply our formalism to neutral Higgs
production via {\bar b}b, gg and W^+ W^- collisions at the LHC. We discuss CP
asymmetries in the longitudinal and transverse polarizations of \tau^+ \tau^-
pairs. The signatures of CP violation are more prominent in the production via
gg and W^+ W^- than via {\bar b}b, and are resonantly enhanced when two (or all
three) neutral Higgs bosons are nearly degenerate with mass differences
comparable to their decay widths. Such scenarios occur naturally in the MSSM
for values of \tan\beta >~ 5 (30) and large (small) charged Higgs-boson masses.
We analyze representative examples with large mixing between the three neutral
Higgs bosons weighing about 120 GeV, that may exhibit observable CP asymmetries
even as large as 80%.


title: $\delta T/T$ and Neutrino Masses in SU(5)

abstract:
  We implement inflation in a supersymmetric SU(5) model with U(1) R-symmetry
such that the cosmic microwave anisotropy $\delta T/T$ is proportional to
$(M/M_{\rm Planck})^2$, where $M\sim M_{GUT}=2-3\times 10^{16}$ GeV, the SU(5)
breaking scale, and $M_{\rm Planck}=2.4\times 10^{19}$ GeV. The presence of a
global $U(1)_X$ symmetry, spontaneously broken also at scale $M_{GUT}$,
provides an upper bound $M_{GUT}^2/M_{\rm Planck}\sim 10^{14}$ GeV on the
masses of SU(5) singlet right handed neutrinos, which explains the mass scale
associated with atmospheric neutrino oscillations. The SU(5) monopoles and
$U(1)_X$ cosmic strings are inflated away. Although the doublet-triplet
splitting requires fine-tuning, the MSSM $\mu$ problem is resolved and
dimension five proton decay is strongly suppressed.


title: Direct experimental test of scalar confinement

abstract:
  The concept of Lorentz scalar quark confinement has a long history and is
still widely used despite its well-known theoretical faults. We point out here
that the predictions of scalar confinement also conflict directly with
experiment. We investigate the dependence of heavy-light meson mass differences
on the mass of the light quark. In particular, we examine the strange and
non-strange D mesons. We find that the predictions of scalar confinement are in
considerable conflict with measured values.


title: Anti-charmed pentaquark $\Theta_c (3099)$ from QCD sum rules

abstract:
  We construct QCD sum rules for the anti-charmed pentaquark $\Theta_c (3099)$,
recently reported at HERA. The sum rules are constructed similarly with the
$\Theta^+ (1540)$ sum rules using the anti-charmed analogue of the $\Theta^+$
interpolating field. The strange quark and quark-gluon mixed condensates, which
were important in the $\Theta^+$ sum rules, are replaced by the gluon
condensates whose contribution to the OPE is suppressed due to the heavy quark
mass. Our result suggests that the parity of $\Theta_c$ is positive. We
identify the difference from the $\Theta^+$ sum rule, which leads to the
positive parity in this heavy-light pentaquark system. The obtained mass is
similar to the experimental value.


title:
Higgs boson pair production in the little Higgs model at hadron
  colliders

abstract:
  The Higgs boson pair production process at hadron collider provides an
opportunity for performing a study of the trilinear Higgs boson self-coupling.
In this paper, we analyze the pair production of a neutral Higgs boson via both
gluon-gluon and $b$-$\bar{b}$ fusions in the littlest Higgs (LH) model at the
CERN LHC. We find that in some parameter space the relative corrections of the
total cross section to the SM prediction may reach a value of 24% when $x ~ (=4
f v'/v^2)=0.95$ at the LHC. We conclude that if the parameter $x$ has a value
above 0.8, the relative corrections contributed by the LH model reach values
beyond 8% and can be observed at the LHC.


title:
The topological approach to baryon-antibaryon and meson production in
  rapidly expanding Bjorken rods

abstract:
  The topological approach to baryon-antibaryon production in the chiral phase
transition is numerically simulated for rapidly expanding hadronic systems. For
that purpose the dynamics of the effective chiral field is implemented on a
space - rapidity lattice. The essential features of evolutions from initial
'hot' configurations into final ensembles of (anti-)baryons embedded in the
chiral condensate are studied in proper time of comoving frames. Typical times
for onset and completion of the roll-down and exponents for the growth of
correlations are extracted. Meson and baryon-antibaryon yields are estimated.
For standard assumptions about initial coherence lengths they are compatible
with experimental results.


title: Exotic Baryons and Monopole Excitations in a Chiral Soliton Model

abstract:
  We compute the spectra of exotic pentaquarks and monopole excitations of the
low--lying ${1/2}^+$ and ${3/2}^+$ baryons in a chiral soliton model. Once the
low--lying baryon properties are fit, the other states are predicted without
any more adjustable parameters. This approach naturally leads to a scenario in
which the mass spectrum of the next to lowest--lying $J^\pi={1/2}^+$ states is
fairly well approximated by the ideal mixing pattern of the
$\mathbf{8}\oplus\bar{\mathbf{10}}$ representation of flavor SU(3). We compare
our results to predictions obtained in other pictures for pentaquarks and
speculate about the spin--parity assignment for $\Xi(1690)$ and $\Xi(1950)$


title: Higher dimensional models of light Majorana neutrinos confronted by data

abstract:
  We discuss experimental and observational constraints on certain models of
higher dimensional light Majorana neutrinos. Models with flavor blind
brane-bulk couplings plus three or four flavor diagonal light Majorana
neutrinos on the brane, with subsequent mixing induced solely by the
Kaluza-Klein tower of states, are found to be excluded by data on the
oscillations of solar, atmospheric and reactor neutrinos, taken together with
the WMAP upper bound on the sum of neutrino masses. Extra dimensions, if
relevant to neutrino mixing, need to discriminate between neutrino flavors.


title: Particle Dark Matter: Evidence, Candidates and Constraints

abstract:
  In this review article, we discuss the current status of particle dark
matter, including experimental evidence and theoretical motivations. We discuss
a wide array of candidates for particle dark matter, but focus on neutralinos
in models of supersymmetry and Kaluza-Klein dark matter in models of universal
extra dimensions. We devote much of our attention to direct and indirect
detection techniques, the constraints placed by these experiments and the reach
of future experimental efforts.


title: Rho - Omega Splitting and Mixing in Nuclear Matter

abstract:
  We investigate the splitting and mixing of $\rho$ and $\omega$ mesons in
nuclear matter. The calculations were performed on the basis of QCD sum rules
and include all operators up to mass dimension-6 twist-4 and up to first order
in the coupling constants. Special attention is devoted to the impact of the
scalar 4-quark condensates on both effects. In nuclear matter the Landau
damping governs the $\rho - \omega$ mass splitting while the scalar 4-quark
condensates govern the strenght of individual mass shifts. A strong in-medium
mass splitting causes the disappearance of the $\rho - \omega$ mixing.


title: Heavy-Quark production in proton-nucleus collision at the LHC

abstract:
  A sizable rate of events, with several pairs of heavy-quarks produced
contemporarily by multiple parton interactions, may be expected at very high
energies as a consequence of the large parton luminosities. The production
rates are enhanced in hadron-nucleus reactions, which may represent a
convenient tool to study the phenomenon. We compare the different contributions
to ccbar bbar pairs production due to single and double parton scatterings, in
collisions of protons with nuclei at the CERN-LHC.


title: New Implications of Lorentz Violation

abstract:
  In this proceedings, I summarize two recently discovered theoretical
implications that Lorentz violation has on physical systems. First, I discuss
new models for neutrino oscillations in which relatively simple combinations of
Lorentz-violating parameters can mimic the major features of the current
neutrino oscillation data. Second, I will present results on Yang-Mills
instantons in Lorentz-violating background fields. An explicit solution is
presented for unit winding number in SU(2).


title: Vacuum Expectation Value of a Wegner-Wilson Loop near the Light Cone

abstract:
  Vacuum expectation values for one Wegner-Wilson loop representing a moving
quark-antiquark pair are calculated in four-dimensional Euclidean and Minkowski
space-time. The calculation uses gluon field strength correlators with
perturbative gluon exchange and non-perturbative correlations from the
stochastic vacuum model. The expectation value of a Wegner-Wilson loop forming
a hyperbolic angle in Minkowski space-time is connected by an analytical
continuation to the expectation value of the Wegner-Wilson loop in Euclidean
four-space. The obtained result shows how confinement enters into the
light-cone Hamiltonian for valence quarks independently of the chosen model.


title: The axial field and quantum states of fermions in closed configurations

abstract: This paper was withdrawn by the author.


title: Inclusive Photoproduction of Lepton Pairs in the Parton Model

abstract:
  In the framework of the QCD parton model, we study unpolarized scattering of
high energy real photons from a proton target into lepton pairs and a system of
hadrons. For a given parametrization of parton distributions in the proton, we
calculate the cross section of this process and show the cancellation of the
interference terms.


title: Scale of Quantum Gravity

abstract:
  In the effective field theory of quantum gravitation coupled to N_s scalars,
N_f fermions, and N_V vectors, tree unitarity is violated at an energy squared
of E_{CM}^2 = 20(G_N N)^{-1}, where N = {2/3}N_s + N_f + 4N_V and G_N is
Newton's constant. This is related to radiative corrections proportional to G_N
N E^2 (where E is the typical energy), due to loops of such particles. New
physics must enter before E_{CM}=5.6 x 10^{18} GeV in the standard model, and
4.6 x 10^{18} GeV in the minimal supersymmetric standard model.


title:
QCD Factorization for Semi-Inclusive Deep-Inelastic Scattering at Low
  Transverse Momentum

abstract:
  We demonstrate a factorization formula for semi-inclusive deep-inelastic
scattering with hadrons in the current fragmentation region detected at low
transverse momentum. To facilitate the factorization, we introduce the
transverse-momentum dependent parton distributions and fragmentation functions
with gauge links slightly off the light-cone, and with soft-gluon radiations
subtracted. We verify the factorization to one-loop order in perturbative
quantum chromodynamics and argue that it is valid to all orders in perturbation
theory.


title: Electroweak Baryogenesis and Dark Matter in the nMSSM

abstract:
  We examine the possibility of electroweak baryogenesis and dark matter in the
nMSSM, a minimal extension of the MSSM with a singlet field. This extension
avoids the usual domain wall problem of the NMSSM, and also appears as the low
energy theory in models of dynamical electroweak symmetry breaking with a
so-called fat-Higgs boson. We demonstrate that a strong, first order
electroweak phase transition, necessary for electroweak baryogenesis, may arise
in regions of parameter space where the lightest neutralino provides an
acceptable dark matter candidate. We investigate the parameter space in which
these two properties are fulfilled and discuss the resulting phenomenology. In
particular, we show that there are always two light CP-even and one light
CP-odd Higgs bosons with masses smaller than about 250 GeV. Moreover, in order
to obtain a realistic relic density, the lightest neutralino mass tends to be
smaller than $M_Z/2$, in which case the lightest Higgs boson decays
predominantly into neutralinos.


title:
CP violation and electric-dipole-moment at low energy tau-pair
  production

abstract:
  CP violation at low energy is investigated at the tau electromagnetic vertex.
High statistics at B factories, and on top of the Upsilon resonances, allows a
detailed investigation of CP-odd observables related to the tau-pair
production. The contribution of the tau electric dipole moment is considered in
detail. We perform an analysis independent from the high energy data by means
of correlation and linear spin observables at low energy. We show that
different CP-odd asymmetries, associated to the normal-transverse and
normal-longitudinal correlation terms can be measured at low energy
accelerators, both at resonant and non resonant energies. These observables
allow to put stringent and independent bounds to the tau electric dipole moment
that are competitive with other high or low energy results.


title: High Energy Photon-Photon Collisions at a Linear Collider

abstract:
  High intensity back-scattered laser beams will allow the efficient conversion
of a substantial fraction of the incident lepton energy into high energy
photons, thus significantly extending the physics capabilities of an
electron-electron or electron-positron linear collider. The annihilation of two
photons produces C=+ final states in virtually all angular momentum states. The
annihilation of polarized photons into the Higgs boson determines its
fundamental two-photon coupling as well as determining its parity. Other novel
two-photon processes include the two-photon production of charged lepton pairs,
vector boson pairs, as well as supersymmetric squark and slepton pairs and
Higgstrahlung. The one-loop box diagram leads to the production of pairs of
neutral particles. High energy photon-photon collisions can also provide a
remarkably background-free laboratory for studying possibly anomalous $W W$
collisions and annihilation. In the case of QCD, each photon can materialize as
a quark anti-quark pair which interact via multiple gluon exchange. The
diffractive channels in photon-photon collisions allow a novel look at the QCD
pomeron and odderon. Odderon exchange can be identified by looking at the heavy
quark asymmetry. In the case of electron-photon collisions, one can measure the
photon structure functions and its various components. Exclusive hadron
production processes in photon-photon collisions test QCD at the amplitude
level and measure the hadron distribution amplitudes which control exclusive
semi-leptonic and two-body hadronic B-decays.


title: Minimal seesaw model with tri/bi-maximal mixing and leptogenesis

abstract:
  We examine minimal seesaw mechanism in which the masses of light neutrinos
are described with tri/bi-maximal mixing in the basis where the charged-lepton
Yukawa matrix and heavy Majorana neutrino mass matrix are diagonal. We search
for all possible Dirac mass textures which contain at least one zero entry in
$3 \times 2$ matrix and evaluate the corresponding lepton asymmetries. We
present the baryon asymmetry in terms of a single low energy unknown, a
Majorana CP phase to be clued from neutrinoless double beta decay.


title:
A Systematic Study of Neutrino Mixing and CP Violation from Lepton Mass
  Matrices with Six Texture Zeros

abstract:
  We present a systematic study of 400 combinations of the charged lepton and
neutrino mass matrices with six vanishing entries or texture zeros. Only 24 of
them, which can be classified into a few distinct categories, are found to be
compatible with current neutrino oscillation data at the $3\sigma$ level. A
peculiar feature of the lepton mass matrices in each category is that they have
the same phenomenological consequences. Taking account of a simple seesaw
scenario for six parallel patterns of the charged lepton and Dirac neutrino
mass matrices with six zeros, we show that it is possible to fit the
experimental data at or below the $2\sigma$ level. In particular, the maximal
atmospheric neutrino mixing can be reconciled with a strong neutrino mass
hierarchy in the seesaw case. Numerical predictions are also obtained for the
neutrino mass spectrum, flavor mixing angles, CP-violating phases and effective
masses of the tritium beta decay and the neutrinoless double beta decay.


title:
Solving the Bethe-Salpeter equation for fermion-antifermion pseudoscalar
  bound state in Minkowski space

abstract:
  The new method of solution of the Bethe-Salpeter equation for quark-antiquark
pseudoscalar bound state is proposed. With the help of integral representation
the results are directly obtained in Minkowski space. Dressing of Greens
functions is naturally considered providing thus the correct inclusion of the
running coupling constant and the quark propagators as well as. The first
numerical results are presented for a simplified ladder approximation.


title: Neutrino oscillation studies with laser-driven beam dump facilities

abstract:
  A new mechanism is suggested for efficient proton acceleration in the GeV
energy range; applications to non-conventional high intensity proton drivers
and, hence, to low-energy (10-200 MeV) neutrino sources are discussed. In
particular we investigate possible uses to explore subdominant $\bar{\nu}_\mu
\to \bar{\nu}_e$ oscillations at the atmospheric scale and their CP conjugate.
We emphasize the opportunity to develop these facilities in conjunction with
projects for inertial confined nuclear fusion and neutron spallation sources.


title:
Lepton Polarization Asymmetry in B\to\ell^{+}\ell^{-} decay Beyond the
  Standard Model

abstract:
  The lepton polarization asymmetry in the B\to\ell^{+}\ell^{-} decay, when one
of the leptons is polarized, is investigated using the most general form of the
effective Hamiltonian. The sensitivity of the asymmetry to the new Wilson
coefficients is studied.Moreover, correlations between the lepton polarization
asymmetry and the branching ratio is studied. It is observed that, there are
not exist such regions of new Wilson coefficients, which the value of branching
ratio coincides with SM result while the lepton polarization does not, i.e new
physics effects can be established by studying lepton polarization only.


title: Predicting F2D3 from the colour glass condensate model

abstract:
  We confront the colour glass condensate motivated dipole model
parameterization of Iancu, Itakura and Munier with the available HERA data on
the diffractive structure function F2D3 and with existing dipole model
parameterizations. Reasonably good agreement is found with only two adjustable
parameters. We caution against interpreting the success of the model as
compelling evidence for low-x perturbative saturation dynamics.


title:
The Skyrme model predictions for the ${\bf 27}_{J=3/2}$ mass spectrum
  and the ${\bf 27}_{3/2}$-$\bar{\bf 10}$ mass splittings

abstract:
  The ${\bf 27}_{J=3/2}$-plet mass spectrum and the ${\bf 27}_{3/2}$-$\bar{\bf
10}$ mass splittings are computed in the framework of the minimal SU(3)$_f$
extended Skyrme model. As functions of the Skyrme charge $e$ and the SU(3)$_f$
symmetry breaking parameters the predictions are presented in tabular form. The
predicted mass splitting ${\bf 27}_{3/2}$-$\bar{\bf 10}$ is the smallest among
all SU(3)$_f$ baryonic multiplets.


title: B decays into light scalar particles and glueball

abstract:
  The recent observations of f_0(980) in charmless B-decays motivate further
studies of scalar particle and glueball production in these processes.
Amplitudes for charmless 2-body B decays involving the members of the scalar
nonet are presented based on the symmetries of the dominant penguin
contribution. Different scenarios for the lightest scalar nonet are
investigated in view of the presently available data. We describe the evidence
from B-decays for f_0(1500) with a flavour octet like mixing and the hints
towards the members of the q qbar nonet of lowest mass. There is further
support for the hypothesis of a broad 0^{++} glueball acting as coherent
background especially in B -> K Kbar K. The estimated B decay rates into
gluonic mesons represent a sizable fraction of the theoretically derived decay
rate for b -> sg.


title: Higher twist analysis of the proton g_1 structure function

abstract:
  We perform a global analysis of all available spin-dependent proton structure
function data, covering a large range of Q^2, 1 < Q^2 < 30 GeV^2, and calculate
the lowest moment of the g_1 structure function as a function of Q^2. From the
Q^2 dependence of the lowest moment we extract matrix elements of twist-4
operators, and determine the color electric and magnetic polarizabilities of
the proton to be \chi_E = 0.026 +- 0.015 (stat) + 0.021/-0.024 (sys) and \chi_B
= -0.013 -+ 0.007 (stat) - 0.010/+0.012 (sys), respectively.


title: Limits on Lorentz Violation from the Highest Energy Cosmic Rays

abstract:
  We place several new limits on Lorentz violating effects, which can modify
particles' dispersion relations, by considering the highest energy cosmic rays
observed. Since these are hadrons, this involves considering the partonic
content of such cosmic rays. We get a number of bounds on differences in
maximum propagation speeds, which are typically bounded at the 10^{-21} level,
and on momentum dependent dispersion corrections of the form v = 1 +-
p^2/Lambda^2, which typically bound Lambda > 10^{21} GeV, well above the Planck
scale. For (CPT violating) dispersion correction of the form v = 1 + p/Lambda,
the bounds are up to 15 orders of magnitude beyond the Planck scale.


title: Little Supersymmetry and the Supersymmetric Little Hierarchy Problem

abstract:
  The current experimental lower bound on the Higgs mass significantly
restricts the allowed parameter space in most realistic supersymmetric models,
with the consequence that these models exhibit significant fine-tuning. We
propose a solution to this `supersymmetric little hierarchy problem'. We
consider scenarios where the stop masses are relatively heavy - in the 500 GeV
to a TeV range. Radiative stability of the Higgs soft mass against quantum
corrections from the top quark Yukawa coupling is achieved by imposing a global
SU(3) symmetry on this interaction. This global symmetry is only approximate -
it is not respected by the gauge interactions. A subgroup of the global
symmetry is gauged by the familiar SU(2) of the Standard Model. The physical
Higgs is significantly lighter than the other scalars because it is the
pseudo-Goldstone boson associated with the breaking of this symmetry. Radiative
corrections to the Higgs potential naturally lead to the right pattern of gauge
and global symmetry breaking. We show that both the gauge and global symmetries
can be embedded into a single SU(6) grand unifying group, thereby maintaining
the prediction of gauge coupling unification. Among the firm predictions of
this class of models are new states with the quantum numbers of 10 and
$\bar{10}$ under SU(5) close to the TeV scale. The Higgs mass is expected to be
below 130 GeV, just as in the MSSM.


title: SuperWIMP Gravitino Dark Matter from Slepton and Sneutrino Decays

abstract:
  Dark matter may be composed of superWIMPs, superweakly-interacting massive
particles produced in the late decays of other particles. We focus on the case
of gravitinos produced in the late decays of sleptons or sneutrinos and assume
they are produced in sufficient numbers to constitute all of non-baryonic dark
matter. At leading order, these late decays are two-body and the accompanying
energy is electromagnetic. For natural weak-scale parameters, these decays have
been shown to satisfy bounds from Big Bang nucleosynthesis and the cosmic
microwave background. However, sleptons and sneutrinos may also decay to
three-body final states, producing hadronic energy, which is subject to even
more stringent nucleosynthesis bounds. We determine the three-body branching
fractions and the resulting hadronic energy release. We find that superWIMP
gravitino dark matter is viable and determine the gravitino and
slepton/sneutrino masses preferred by this solution to the dark matter problem.
In passing, we note that hadronic constraints disfavor the possibility of
superWIMPs produced by neutralino decays unless the neutralino is photino-like.


title: A_4 Symmetry and Neutrinos with Very Different Masses

abstract:
  The A_4 model of leptons was proposed originally for nearly degenerate
neutrino masses. With minimal modification, it is shown to accommodate as well
the cases of normal hierarchy and inverted hierarchy. In all cases, this new
model predicts sin^2 2 theta_{atm} = 1 and tan^2 theta_{sol} = 0.5 for U_{e3} =
0. It also predicts their deviations from 1 and 0.5 respectively for U_{e3} not
equal to zero.


title:
A Circumstantial Evidence for the Possible Production of QGP in the 158A
  GeV/c Central Pb+Pb Collisions

abstract:
  Hadron and string cascade model (JPCIAE) with the hypothesis without
introducing the quark-gluon plasma (QGP), is employed to study the direct
photon and $\pi^0$ transverse momentum distributions for central
$^{208}$Pb+$^{208}$Pb collisions at 158A GeV/c . JPCIAE model, is based on LUND
model, especially on the envent generator PYTHIA, and can be used to simulate
the relativistic nucleus-nucleus collisions where PYTHIA is called to deal with
hadron-hadron collisions. In our work, the theoretical results of transverse
momentum distribution for both the direct photon and the $\pi^0$ particle are
lower than the data of WA98 experiment. However, JPCIAE model can ever explain
successfully the results of WA80 and WA93 experiments of central S+Au
collisions at 200A GeV/c where no evidence of direct photon excess. Having
considered the results of WA80 and WA93 experiments can be explained but WA98's
can't, that might provide a circumstantial evidence for the possible production
of QGP in the high-energy central Pb+Pb collisions.


title: Quantum Hall States of Gluons in Quark Matter

abstract:
  We have recently shown that dense quark matter possesses a color
ferromagnetic phase in which a stable color magnetic field arises
spontaneously. This ferromagnetic state has been known to be Savvidy vacuum in
the vacuum sector. Although the Savvidy vacuum is unstable, the state is
stabilized in the quark matter. The stabilization is achieved by the formation
of quantum Hall states of gluons, that is, by the condensation of the gluon's
color charges transmitted from the quark matter. The phase is realized between
the hadronic phase and the color superconducting phase. After a review of
quantum Hall states of electrons in semiconductors, we discuss the properties
of quantum Hall states of gluons in quark matter in detail. Especially, we
evaluate the energy of the states as a function of the coupling constant. We
also analyze solutions of vortex excitations in the states and evaluate their
energies. We find that the states become unstable as the gauge coupling
constant becomes large, or the chemical potential of the quarks becomes small,
as expected. On the other hand, with the increase of the chemical potential,
the color superconducting state arises instead of the ferromagnetic state. We
also show that the quark matter produced by heavy ion collisions generates
observable strong magnetic field $\sim 10^{15}$ Gauss when it enters the
ferromagnetic phase.


title: QCD and models on multiplicities in $e^+e^-$ and $p\bar p$ interactions

abstract:
  A brief survey of theoretical approaches to description of multiplicity
distributions in high energy processes is given. It is argued that the
multicomponent nature of these processes leads to some peculiar characteristics
observed experimentally. Predictions for LHC energies are presented. It is
shown that similarity of the energy dependence of average multiplicities in
different reactions is not enough alone to suggest the universal mechanism of
particle production in strongly-interacting systems. Other characteristics of
multiplicity distributions depend on the nature of colliding partners.


title:
The s-wave pi d scattering length from pi d atom using effective field
  theory

abstract:
  The pi- d atom strong energy-level shift in the 1s state is derived by using
the effective field theory. Taking into account the large value of radius of
pionic deuterium and short radius of strong interaction between pion and
deuteron we have considered deuteron as particle described by vector field.
Pion is described by scalar field. To obtain non-relativistic Hamiltonian for
pi d system Foldy-Wouthuysen transformation has been derived for the vector
field. The strong interaction between pion and deuteron has been taken at the
zero-range approach. We have found the Deser type formula for relation between
the strong energy-level shift and the s-wave pi d scattering length.


title: Scattering amplitudes at multi TeV energies

abstract:
  We show that a generalized Regge behaviour, $$Im F(s,t)\simeq \Phi(t)(\log
s/\hat{s})^{\nu(t)}(s/\hat{s})^{\alpha_P(t)},\quad{\rm for} |t|<|t_0|,
s\to\infty$$ where $\Phi(t)\simeq e^{bt}$, $\alpha_P(t)\simeq
\alpha_P(0)+\alpha'_P(0)t$, and $t_0$ is the first zero of $\alpha_P(t)$,
$\alpha_P(t_0)=0$, implies that the corresponding cross section is bounded by
$$\sigma_{\rm tot}(s)<({\rm Const.})\times\log s/\hat{s}.$$ This growth,
however, is not sufficient to fit the experimental cross sections. If, instead
of this, we assume saturation of the improved Froissart bound, i.e., a
behaviour $$Im F(s,0)\simeq A(s/\hat{s})\log^2{{s}\over{s_1\log^{7/2} s/s_2}},
$$ a good fit is obtained to $\pi\pi$, $\pi N$, $KN$ and $NN$ cross sections
from c.m. kinetic energy $E_{\rm kin}\simeq1 $ GeV to 30 TeV (producing a cross
section of $108\pm6$ mb at LHC energy). This suggests that the Regge-type
behaviour only holds for values of the momentum transfer very near zero.


title: Signatures of a minimal length scale in high precision experiments

abstract:
  We discuss modifications of the gyromagnetic moment of electrons and muons
due to a minimal length scale combined with a modified fundamental scale $M_f$.
First-order deviations from the theoretical standard model value for $g-2$ due
to these String Theory-motivated effects are derived. A constraint of $M_f>577
GeV$ for the new fundamental scale is given.


title: Beam normal spin asymmetry in elastic lepton-nucleon scattering

abstract:
  We discuss the two-photon exchange contribution to observables which involve
lepton helicity flip in elastic lepton-nucleon scattering. This contribution is
accessed through the spin asymmetry for a lepton beam polarized normal to the
scattering plane. We estimate this beam normal spin asymmetry at large momentum
transfer using a parton model and we express the corresponding amplitude in
terms of generalized parton distributions.


title:
Critical Opacity - a possible explanation of the fast thermalisation
  times seen in RHIC experiments

abstract:
  The Nambu Jona-Lasinio Lagrangian offers an explication of the seemingly
contradictory observations that a) the energy loss in the entrance channel of
heavy ion reactions is not sufficient to thermalize the system and that b) the
observed hadron cross sections are in almost perfect agreement with
hydrodynamical calculations. According to this scenario, a critical opacity
develops close to the chiral phase transition which equilibrates and hadronizes
the expanding system very effectively. It creates as well radial flow and, if
the system is not isotropic, finite $v_2$ values.


title: Finite Unified Theories and the Higgs mass prediction

abstract:
  Finite Unified Theories (FUTs) are N=1 supersymmetric Grand Unified Theories,
which can be made all-loop finite, both in the dimensionless (gauge and Yukawa
couplings) and dimensionful (soft supersymmetry breaking terms) sectors. This
remarkable property provides a drastic reduction in the number of free
parameters, which in turn leads to an accurate prediction of the top quark mass
in the dimensionless sector, and predictions for the Higgs boson mass and the
supersymmetric spectrum in the dimensionful sector. Here we examine the
predictions of two FUTs taking into account a number of theoretical and
experimental constraints. For the first one we present the results of a
detailed scanning concerning the Higgs mass prediction, while for the second we
present a representative prediction of its spectrum.


title:
Transverse energy per charged particle at relativistic energies from a
  statistical model with expansion

abstract:
  Transverse energy and charged particle pseudorapidity densities at
midrapidity and their ratio, $dE_{T}/d\eta\mid_{mid} / dN_{ch}/d\eta|_{mid}$,
are evaluated in a statistical model with longitudinal and transverse flows for
the wide range of colliders, from AGS to RHIC at $\sqrt{s_{NN}}=200$ GeV.
Evaluations are done at freeze-out parameters established independently from
fits to observed particle yields and $p_{T}$ spectra. Decays of hadron
resonances are treated thoroughly and are included in derivations of
$dE_{T}/d\eta|_{mid}$ and $dN_{ch}/d\eta|_{mid}$. The predictions of the model
agree well with the experimental data. However, some (explicable)
overestimation of the ratio has been observed.


title: Charm quark-antiquark correlations in photon-proton scattering

abstract:
  Correlation of charm quark - charm antiquark in $\gamma p$ scattering are
calculated in the $k_t$-factorization approach. We apply different unintegrated
gluon distributions (uGDF) used in the literature. The results of our
calculations are compared with very recent experimental results from the FOCUS
collaboration. The CCFM uGDF developed recently by Kwieci\'nski et al. gives a
good description of the data. New observables are suggested for future studies.
Predictions and perspectives for the HERA energies are presented.


title: Anatomy and Phenomenology of mu-tau Lepton Flavour Violation in the MSSM

abstract:
  We perform a detailed analysis of several mu-tau lepton flavour violating
(LFV) processes, namely tau --> mu X (X = gamma, e+ e-, mu+ mu-, rho, pi, eta,
eta'), Z --> mu tau and Higgs boson decays into mu tau. First we present a
model independent operator analysis relevant to such decays, then we explicitly
compute the LFV operator coefficients [and (g_\mu -2)] in a general
unconstrained MSSM framework, allowing slepton mass matrices to have large
mu-tau entries. We systematically study the role and the interplay of dipole
and non-dipole operators, showing how the rates and the mutual correlations of
those LFV decays change in different regions of the MSSM parameter space.Values
of the LFV branching ratios in the experimentally interesting range
10^{-9}-10^{-7} can be achieved. For at least two MSSM Higgs bosons, the
branching ratio of the LFV decay into mu tau can reach values of order 10^{-4}.


title: Comment on the Theta+ width and mass

abstract:
  We discuss the relatively low mass and narrow width prediction for the exotic
baryon Theta+, and comment on recent statements by R.L. Jaffe on the subject.
We reaffirm that a narrow width of 3.6-11.2 MeV follows from the equations of
our 1997 paper.


title:
Steps towards full two-loop calculations for 2 fermion to 2 fermion
  processes: running versus pole masses schemes

abstract:
  Recent progress in the calculation of the two-loop on-shell mass counterterms
within the electroweak Standard Model (SM) for the massive particles are
discussed. We are in progress of developing a package for full two-loop SM
calculations of 2 -> 2 fermion processes, with emphasis on the analytical
approach where feasible. The complete two-loop on-shell renormalization is
implemented. Substantial progress has been made in calculating the master
integrals. We are able to compute in an efficient and stable manner up to a few
thousands of diagrams of very complex mass structure.


title: Illuminating interfaces between phases of a U(1) x U(1) gauge theory

abstract:
  We study reflection and transmission of light at the interface between
different phases of a U(1) x U(1) gauge theory. On each side of the interface,
one can choose a basis so that one generator is free (allowing propagation of
light), and the orthogonal one may be free, Higgsed, or confined. However, the
basis on one side will in general be rotated relative to the basis on the other
by some angle alpha. We calculate reflection and transmission coefficients for
both polarizations of light and all 8 types of boundary, for arbitrary alpha.
We find that an observer measuring the behavior of light beams at the boundary
would be able to distinguish 4 different types of boundary, and we show how the
remaining ambiguity arises from the principle of complementarity
(indistinguishability of confined and Higgs phases) which leaves observables
invariant under a global electric/magnetic duality transformation. We also
explain the seemingly paradoxical behavior of Higgs/Higgs and confined/confined
boundaries, and clarify some previous arguments that confinement must involve
magnetic monopole condensation.


title: Fifty years of Yang-Mills Theories: a phenomenological point of view

abstract:
  On the occasion of the celebration of the first half-century of Yang--Mills
theories, I am contributing a personal recollection of how the subject, in its
early times, confronted physical reality, that is, its "phenomenology". There
is nothing original in this work, except, perhaps, my own points of view. But I
hope that the older practitioners of the field will find here grounds for
nostalgia, or good reasons to disagree with me. Younger addicts may learn that
history does not resemble at all what is reflected in current textbooks: it was
orders of magnitude more fascinating.


title: The Gribov Conception of Quantum Chromodynamics

abstract:
  A major contribution to the quest of constructing quantum dynamics of
non-Abelian fieds is due to V.N. Gribov. Perturbative approach to the colour
confinement, both in gluodynamics and the real world, was long considered
heretic but is gaining ground. We discuss Gribov's approach to the confinement
problem, centered around the role played by light quarks - the supercritical
light quark confinement scenario. We also review some recent developments that
are motivated, directly or indirectly, by his ideas.


title:
Sudakov Resummation for Subleading SCET Currents and Heavy-to-Light Form
  Factors

abstract:
  The hard-scattering contributions to heavy-to-light form factors at large
recoil are studied systematically in soft-collinear effective theory (SCET).
Large logarithms arising from multiple energy scales are resummed by matching
QCD onto SCET in two stages via an intermediate effective theory. Anomalous
dimensions in the intermediate theory are computed, and their form is shown to
be constrained by conformal symmetry. Renormalization-group evolution equations
are solved to give a complete leading-order analysis of the hard-scattering
contributions, in which all single and double logarithms are resummed. In two
cases, spin-symmetry relations for the soft-overlap contributions to form
factors are shown not to be broken at any order in perturbation theory by
hard-scattering corrections. One-loop matching calculations in the two
effective theories are performed in sample cases, for which the relative
importance of renormalization-group evolution and matching corrections is
investigated. The asymptotic behavior of Sudakov logarithms appearing in the
coefficient functions of the soft-overlap and hard-scattering contributions to
form factors is analyzed.


title: Brane solution with an increasing warp factor

abstract:
  We present a new brane solution in the (1+5)-dimensional space-time with an
increasing warp factor, which localizes the zero modes of all kinds of matter
fields and Newtonian gravity. The interesting features of this solution are: 1)
In contrast to the Gogberashvili-Singleton case the effective wave function of
the zero mode spinor field confined on the brane is finite at a position of
brane; 2) There is exactly one zero mode for each matter field and the
gravitational field confined on the brane with a finite probability and
infinitely many zero modes (labelled by the angular momentum corresponding to
extra space) are located in the bulk at different localization radii.


title: NJL Model at Finite Chemical Potential in a Constant Magnetic Field

abstract:
  We investigate the influence of an external magnetic field on chiral symmetry
breaking in the Nambu-Jona-Lasinio (NJL) model at finite temperature and
chemical potential. According to the Fock-Schwinger proper-time method, we
calculate the effective potential in the leading order of the $1/N_c$
expansion. The phase boundary dividing the symmetric phase and the broken phase
is illustrated numerically. A complex behavior of the phase boundary is found
for large chemical potential.


title:
b-physics signals of the lightest CP-odd Higgs in the NMSSM at large tan
  beta

abstract:
  We investigate the low energy phenomenology of the lighter pseudoscalar
$A_1^0$ in the NMSSM. The $A_1^0$ mass can naturally be small due to a global
$U(1)_R$ symmetry of the Higgs potential, which is only broken by trilinear
soft terms. The $A_1^0$ mass is further protected from renormalization group
effects in the large $\tan \beta$ limit. We calculate the $b \to s A_1^0$
amplitude at leading order in $\tan \beta$ and work out the contributions to
rare $K$, $B$ and radiative $\Upsilon$-decays and $B -\bar B$ mixing. We obtain
constraints on the $A_1^0$ mass and couplings and show that masses down to
${\cal{O}}(10)$ MeV are allowed. The $b$-physics phenomenology of the NMSSM
differs from the MSSM in the appearance of sizeable renormalization effects
from neutral Higgses to the photon and gluon dipole operators and the breakdown
of the MSSM correlation between the $B_s \to \mu^+ \mu^-$ branching ratio and
$B_s - \bar B_s$ mixing. For $A_1^0$ masses above the tau threshold the $A_1^0$
can be searched for in $b \to s \tau^+ \tau^-$ processes with branching ratios
$\lsim 10^{-3}$.


title:
A Unitarized Chiral Approach to f0(980) and a0(980) States and Nature of
  Light Scalar Resonances

abstract:
  We show that the f_0(980) and a_0(980) states appearing in scattering and
production processes can be described quite well by the two-channel
Oller-Oset-Pel\'aez (OOP) version of unitarized chiral theories. It is
impossible, however, to deduce a conclusion on the nature of them from the
fitting to experimental data alone. Using explicit N_c dependence of parameters
in OOP amplitudes we demonstrate that light scalar resonances are not of q\bar
q states but dynamical rescattering effects generated under chiral symmetry,
unitarity and channel couplings.


title:
Out-of-Equilibrium Collinear Enhanced Equilibration in the Bottom-Up
  Thermalization Scenario in Heavy Ion Collisions

abstract:
  Experimental measurement of the elliptic flow parameter $v_2$ and
hydrodynamic model together showed that thermalization in the central region at
the Relativistic Heavy Ion Collider to be perplexingly fast. This is a mystery
in itself since none of the numerical perturbative QCD models are able to
achieve such a feat. By exploiting a theoretical oversight on collinear
processes in an out-of-equilibrium system it is argued that, in the bottom-up
thermalization scenario, equilibration can proceed at a higher rate than what
is expected in the conventional perturbative QCD picture.


title: Modelling the light quark vacuum

abstract:
  The triumphs of the Standard Model of Particle Physics call attention upon an
old idea, that the so-called vacuum is an accessible physical medium, and not
just a tautology.
  I take this idea as a serious working hypothesis, and I suggest a new way of
trying to define and understand the structure of the light quark vacuum within
the general framework of the Standard Model.


title:
Coulomb corrections to bremsstrahlung in electric field of heavy atom at
  high energies

abstract:
  The differential and partially integrated cross sections are considered for
bremsstrahlung from high-energy electrons in atomic field with the exact
account of this field. The consideration exploits the quasiclassical electron
Green's function and wave functions in an external electric field. It is shown
that the Coulomb corrections to the differential cross section are very
susceptible to screening. Nevertheless, the Coulomb corrections to the cross
section summed up over the final-electron states are independent of screening
in the leading approximation over a small parameter $1/mr_{scr}$ ($r_{scr}$ is
a screening radius, $m$ is the electron mass, $\hbar=c=1$). Bremsstrahlung from
an electron beam of the finite size on heavy nucleus is considered as well.
Again, the Coulomb corrections to the differential probability are very
susceptible to the beam shape, while those to the probability integrated over
momentum transfer are independent of it, apart from the trivial factor, which
is the electron-beam density at zero impact parameter. For the Coulomb
corrections to the bremsstrahlung spectrum, the next-to-leading terms with
respect to the parameters $m/\epsilon$ ($\epsilon$ is the electron energy) and
$1/mr_{scr}$ are obtained.


title:
Inclusive electromagnetic decays of the heavy quarkonium at next to
  leading log accuracy

abstract:
  We show that perturbation theory may give reasonable numbers for the decays
of the bottomonium and charmonium ground states to $e^+e^-$ and to
$\gamma\gamma$. To reach this conclusion it is important to perform the
resummation of logs. In particular, we obtain the value $\Gamma(\eta_b (1S) \to
\gamma\gamma)=0.35 \pm 0.1 ({\rm th.}) \pm 0.05 (\lQ)$ KeV.


title: Observation of the Second Tensor Nonet with the L3 Experiment

abstract:
  This paper was withdrawn by arXiv administrators upon request of the
Chairperson and Spokesperson of the L3 Collaboration.


title: Spontaneous formation of domain wall lattices in two spatial dimensions

abstract:
  We show that the process of spontaneous symmetry breaking can trap a field
theoretic system in a highly non-trivial state containing a lattice of domain
walls. In one large compact space dimension, a lattice is inevitably formed. In
two dimensions, the probability of lattice formation depends on the ratio of
sizes L_x, L_y of the spatial dimensions. We find that a lattice can form even
if R=L_y/L_x is of order unity. We numerically determine the number of walls in
the lattice as a function of L_x and L_y.


title: Beyond the Standard Model in Many Directions

abstract:
  These four lectures constitute a gentle introduction to what may lie beyond
the standard model of quarks and leptons interacting through $SU(3)_c \otimes
SU(2)_L \otimes U(1)_Y$ gauge bosons, prepared for an audience of graduate
students in experimental particle physics. In the first lecture, I introduce a
novel graphical representation of the particles and interactions, the double
simplex, to elicit questions that motivate our interest in physics beyond the
standard model, without recourse to equations and formalism. Lecture 2 is
devoted to a short review of the current status of the standard model,
especially the electroweak theory, which serves as the point of departure for
our explorations. The third lecture is concerned with unified theories of the
strong, weak, and electromagnetic interactions. In the fourth lecture, I survey
some attempts to extend and complete the electroweak theory, emphasizing some
of the promise and challenges of supersymmetry. A short concluding section
looks forward.


title: K+ -> pi+ nu nu(bar) and FCNC from non-universal Z' bosons

abstract:
  Motivated by the E787 and E949 result for K+ -> pi+ nu nu(bar) we examine the
effects of a new non-universal right-handed Z' boson on flavor changing
processes. We place bounds on the tree-level FCNC from K-K(bar) and B-B(bar)
mixing as well as from the observed CP violation in kaon decay. We discuss the
implications for K -> pi nu nu(bar), B -> X nu nu(bar) and B -> tau+ tau-. We
find that existing bounds allow substantial enhancements in the K+ -> pi+ nu
nu(bar) rate, particularly through a new one-loop Z' penguin operator.


title: V-A sum rules with D=10 operators

abstract:
  The difference of vector and axial-vector charged current correlators is
analyzed by means of QCD sum rules. The contribution of 10-dimensional 4-quark
condensates is calculated and its value is estimated within the framework of
factorization hypothesis. It is compared to the result, obtained from operator
fit of Borel sum rules in the complex q^2-plane, calculated from experimental
data on hadronic tau-decays. This fit gives accurate values of the light quark
condensate and quark-gluon mixed condensate. The size of the high-order
operators and the convergence of operator series are discussed.


title: Supergravity with a Gravitino LSP

abstract:
  We investigate supergravity models in which the lightest supersymmetric
particle (LSP) is a stable gravitino. We assume that the next-lightest
supersymmetric particle (NLSP) freezes out with its thermal relic density
before decaying to the gravitino at time t ~ 10^4 s - 10^8 s. In contrast to
studies that assume a fixed gravitino relic density, the thermal relic density
assumption implies upper, not lower, bounds on superpartner masses, with
important implications for particle colliders. We consider slepton, sneutrino,
and neutralino NLSPs, and determine what superpartner masses are viable in all
of these cases, applying CMB and electromagnetic and hadronic BBN constraints
to the leading two- and three-body NLSP decays. Hadronic constraints have been
neglected previously, but we find that they provide the most stringent
constraints in much of the natural parameter space. We then discuss the
collider phenomenology of supergravity with a gravitino LSP. We find that
colliders may provide important insights to clarify BBN and the thermal history
of the Universe below temperatures around 10 GeV and may even provide precise
measurements of the gravitino's mass and couplings.


title: Thermal pion masses in the second phase: $|\mu_{I}| >m_{\pi}$

abstract:
  Density and thermal corrections to the mass of the pions are studied in the
framework of the SU(2) low energy effective chiral lagrangian, in terms of the
isospin chemical potential $\mu_\tin{I}$. We concentrate the discussion in the
region where the isospin chemical potential (absolute value) becomes bigger
than the pion mass at zero temperature and density, i.e. in the phase where the
condensed $\pi^-$ phase appears (for negative chemical potential). We are able
to calculate the thermal and density evolution of masses in the limits where
$|\mu_{I}|\gg m$ and where $|\mu_{I}| \gtrsim m$. We also identified the phase
transition curve.


title: Lepton Flavor Violation without Supersymmetry

abstract:
  We study the lepton flavor violating (LFV) processes mu -> e gamma, mu -> 3e,
and mu -> e conversion in nuclei in the left-right symmetric model without
supersymmetry and perform the first complete computation of the LFV branching
ratios B(mu -> f) to leading non-trivial order in the ratio of left- and
right-handed symmetry breaking scales. To this order, B(mu -> e gamma) and B(mu
-> e) are governed by the same combination of LFV violating couplings, and
their ratio is naturally of order unity. We also find B(mu -> 3 e)/B(mu -> e)
\sim 100 under slightly stronger assumptions. Existing limits on the branching
ratios already substantially constrain mass splittings and/or mixings in the
heavy neutrino sector. When combined with future collider studies and precision
electroweak measurements, improved limits on LFV processes will test the
viability of low-scale, non-supersymmetric LFV scenarios.


title: Neutrino Propagation in a Strongly Magnetized Medium

abstract:
  We derive general expressions at the one-loop level for the coefficients of
the covariant structure of the neutrino self-energy in the presence of a
constant magnetic field. The neutrino energy spectrum and index of refraction
are obtained for neutral and charged media in the strong-field limit ($M_{W}\gg
\sqrt{B}\gg m_{e},T,\mu ,| \mathbf{p}| $) using the lowest Landau level
approximation. The results found within the lowest Landau level approximation
are numerically validated, summing in all Landau levels, for strong $B\gg
T^{2}$ and weakly-strong $B \gtrsim T^{2}$ fields. The neutrino energy in
leading order of the Fermi coupling constant is expressed as the sum of three
terms: a kinetic-energy term, a term of interaction between the magnetic field
and an induced neutrino magnetic moment, and a rest-energy term. The leading
radiative correction to the kinetic-energy term depends linearly on the
magnetic field strength and is independent of the chemical potential. The other
two terms are only present in a charged medium. For strong and weakly-strong
fields, it is found that the field-dependent correction to the neutrino energy
in a neutral medium is much larger than the thermal one. Possible applications
to cosmology and astrophysics are considered.


title:
Non-Gaussian Finite Temperature Statistics of the Longitudinal Gauge
  Excitation of the Higgs Vacuum

abstract:
  Real time excitations in the broken symmetry phase of the classical Abelian
Higgs model are investigated numerically in the unitary gauge. Persistent
correlation is detected at finite energy density between the scalar and the
longitudinal vector modes, the latter itself displaying non-Gaussian
fluctuations. The effect diminishes when the energy density is lowered.
Candidate effective mode variables are constructed by non-linear canonical
point transformations. Their dispersion relations and equations of state are
carefully tested.


title: PHASE - An event generator for six fermion physics at the LHC

abstract:
  PHASE is a Monte Carlo event generator, under construction, for all Standard
Model processes with six fermions in the final state at the LHC. It employs the
full set of tree level Feynman diagrams, taking into account fermion masses for
b quarks. The program can generate unweighted events for any subset of all six
fermion final states in a single run, by making use of dedicated pre-samples.
An interface to hadronization is provided.


title: Constraining the string scale: from Planck to Weak and back again

abstract:
  String and field theory ideas have greatly influenced each other since the so
called second string revolution. We review this interrelation paying particular
attention to its phenomenological implications. Our guiding principle is the
radical shift in the way that we think about the fundamental scale, in
particular the way in which string models have been able to accommodate values
from the Planck $M_\mathrm{Pl}\sim 10^{18}$ GeV down to the electroweak scale
$M_{EW}\sim $ TeV.


title: On Extended Electroweak Symmetries

abstract:
  We discuss extensions of the Standard Model through extending the electroweak
gauge symmetry. An extended electroweak symmetry requires a list of extra
fermionic and scalar states. The former is necessary to maintain cancellation
of gauge anomalies, and largely fixed by the symmetry embedding itself. The
latter is usually considered quite arbitrary, so long as a vacuum structure
admitting the symmetry breaking is allowed. Anomaly cancellation may be used to
link the three families of quarks and leptons together, given a perspective on
flavor physics. It is illustrated lately that the kind of models may also have
the so-called little Higgs mechanism incorporated. This more or less fixes the
scalar sector and take care of the hierarchy problem, making such models of
extended electroweak symmetries quite appealing candidates as TeV scale
effective field theories.


title: Cosmological neutrinos

abstract:
  The current status of neutrino cosmology is reviewed, from the question of
neutrino decoupling and the presence of sterile neutrinos to the effects of
neutrinos on the cosmic microwave background and large scale structure.
Particular emphasis is put on cosmological neutrino mass measurements.