title: Noncommutativity in Space and Primordial Magnetic Field

abstract:
  In this paper we show that noncommutativity in spatial coordinates can
generate magnetic field in the early Universe on a horizon scale. The strength
of such a magnetic field depends on the number density of massive charged
particles present at a given moment. This allows us to trace back the
temperature dependence of the noncommutativity scale from the bounds on
primordial magnetic field coming from nucleosynthesis.


title: Electroweak Precision Tests with GigaZ

abstract:
  By running the prospective high-energy e^+e^- collider TESLA in the GigaZ
mode on the Z resonance, experiments can be performed on the basis of more than
10^9 Z events. This will allow the measurement of the effective electroweak
mixing angle to an accuracy of \delta sin^2(theta_W,eff) \approx \pm 10^-5. The
W boson mass is likewise expected to be measurable with an error of \delta M_W
\approx \pm 6 MeV near the W^+W^ threshold. We review the electroweak precision
tests that can be performed with these high precision measurements within the
Standard Model (SM) and its minimal Supersymmetric extension (MSSM). The
complementarity of direct measurements at a prospective linear e^+e^- collider
and indirect constraints following from measurements performed at GigaZ is
emphasized.


title:
Consequences of the Factorization Hypothesis in pbar p, pp, gamma p and
  gamma gamma Collisions

abstract:
  Using an eikonal analysis, we examine the validity of the factorization
theorem for nucleon-nucleon, gamma p and gamma gamma collisions. As an example,
using the additive quark model and meson vector dominance, we directly show
that for all energies and values of the eikonal, that the factorization theorem
sigma_{nn}/sigma_{gamma p} = sigma_{gamma p}/sigma_{gamma gamma} holds. We can
also compute the survival probability of large rapidity gaps in high energy
pbar p and pp collisions. We show that the survival probabilities are identical
(at the same energy) for gamma p and gamma gamma collisions, as well as for
nucleon-nucleon collisions. We further show that neither the factorization
theorem nor the reaction-independence of the survival probabilities depends on
the assumption of an additive quark model, but, more generally, depends on the
opacity of the eikonal being independent of whether the reaction is n-n, gamma
p or gamma gamma.


title:
Three Active and Two Sterile Neutrinos in an E_6 Model of Diquark
  Baryogenesis

abstract:
  In the U(1)_N extension of the supersymmetric standard model with E_6
particle content, the heavy singlet superfield N may decay into a quark and a
diquark as well as an antiquark and an antidiquark, thus creating a baryon
asymmetry of the Universe. We show how the three doublet and two singlet
neutrinos in this model acquire mass from physics at the TeV scale without the
benefit of using N as a heavy right-handed neutrino. Specifically, the active
neutrinos get masses via the bilinear term \mu LX^c which conserves R-parity,
and via the nonzero masses of the sterile neutrinos. We predict fixed
properties of the extra Z' boson, as well as the new lepton doublets X and X^c,
and the observation of diquark resonances at hadron colliders in this scenario.


title: Inelastic diffractive scattering in nonperturbative QCD

abstract:
  We examine diffractive proton-proton scattering p p -> p X and photo- and
electroproduction of \rho^0 mesons \gamma^(*) p -> \rho^0 X, where X denotes a
proton or a final state, into which the proton can go by diffractive
dissociation. Using a functional integral approach we derive the scattering
amplitudes, which are governed by the expectation values of light-like
Wegner-Wilson loops, which are then evaluated using the model of the stochastic
vacuum. For the proton, we assume a quark-diquark structure. From the
scattering amplitudes we calculate total and differential cross sections for
high centre of mass energy and small momentum transfer and compare with
experiments. Furthermore we calculate isovector form factors for the proton and
the pion within the same model.


title: High Temperature Expansion for a Chain Model

abstract:
  We consider an arbitrary translationally invariant chain model with nearest
neighbors interaction and satisfying periodic boundary condition.
  The approach developed here allows a thermodynamic description of the chain
model directly in terms of grand potential per site. This thermodynamic
function is derived from an auxiliary function constructed only from open
connected sub-chains. In order to exemplify its application and how this
approach works we consider the Heisenberg XXZ model. We obtain the coefficients
of the high temperature expansion of the free energy per site of the model up
to third order.


title: Q-ball Evolution, B-ball Baryogenesis and the f_{B} Problem

abstract:
  We consider some of the issues surrounding the formation and evolution of
Q-balls in the MSSM and its extensions. The ratio of the baryon number packed
into Q-balls to that outside, f_{B}, plays a fundamental role in determining
the relationship of dark matter to the baryon number in the Universe at
present. The final value of f_{B} will depend upon the details of the formation
of Q-balls from the collapse of the Affleck-Dine condensate and upon the
subsequent evolution of the ensemble of Q-balls. We discuss the implications
for neutralino dark matter in the gravity-mediated scenario and show that a
light neutralino is necessary in most cases to account for the baryon to dark
matter ratio, with an NMSSM singlino LSP of mass m_{\chi} \lae 20 \GeV being a
favoured candidate.


title:
Neutralino-Nucleus Elastic Cross Section in the Minimal Supersymmetric
  Standard Model with Explicit CP Violation

abstract:
  We study the elastic scattering of the lightest neutralino with a nucleus in
the framework of the minimal supersymmetric standard model (MSSM) with explicit
flavor preserving CP violation, including the one-loop CP-violating neutral
Higgs-boson mixing effects induced dominantly by the CP phases in the top and
bottom (s)quark sectors. We construct the most general form of the effective
Lagrangian for the neutralino-nucleus scattering in the limit of vanishing
momentum transfers and then we perform a comprehensive analysis of the effects
of the complex CP phases on the mass spectra of the lightest neutralino,
neutral Higgs bosons and top squarks, and on the the spin-dependent and
spin-independent neutralino-nucleus scattering cross section for three neucleus
targets F, Si and Ge. The CP phases can reduce or enhance the
neutralino-nucleus cross sections significantly, depending on the values of the
real parameters in the MSSM.


title:
A New Prediction for Direct CP Violation \epsilon'/\epsilon and \Delta I
  = 1/2 Rule

abstract:
  The low energy dynamics of QCD is investigated with special attention paid to
the matching between QCD and chiral perturbation theory(ChPT), and also to some
useful algebraic chiral operator relations which survive even when we include
chiral loop corrections. It then allows us to evaluate the hadronic matrix
elements below the energy scale $\Lambda_{\chi} \simeq 1$ GeV. Based on the new
analyzes, we present a consistent prediction for both direct CP-violating
parameter $\epsilon'/\epsilon$ and $\Delta I =1/2$ rule in the kaon decays. In
the leading $1/N_c$ approximation, the isospin amplitudes $A_0$ and $A_2$ are
found to agree well with the data, and the direct CP-violating parameter
$\epsilon'/\epsilon$ is predicted to be large, which also confirms our early
conclusion. Its numerical value is $\epsilon'/\epsilon =
23.6^{+12.4}_{-7.8}\times 10^{-4}(Im\lambda_t/1.2\times 10^{-4})$ which is no
longer sensitive to the strange quark mass due to the matching conditions.
Taking into account a simultaneous consistent analysis on the isospin
amplitudes $A_0$ and $A_2$, the ratio $\epsilon'/\epsilon$ is in favor of the
values $\epsilon'/\epsilon = (20\pm 9)\times 10^{-4}$.


title:
Radiative-Recoil Corrections of Order $\alpha(Z\alpha)^5(m/M)m$ to Lamb
  Shift Revisited

abstract:
  The results and main steps of an analytic calculation of radiative-recoil
corrections of order $\alpha(Z\alpha)^5(m/M)m$ to the Lamb shift in hydrogen
are presented. The calculations are performed in the infrared safe Yennie
gauge. The discrepancy between two previous numerical calculations of these
corrections existing in the literature is resolved. Our new result eliminates
the largest source of the theoretical uncertainty in the magnitude of the
deuterium-hydrogen isotope shift.


title: Neutrino Masses and SO(10) SUSY GUTs

abstract:
  In this talk I discuss the qualitative features of an SO(10) SUSY GUT with an
SU(2)x U(1)$^n$ family symmetry. I then describe the global fit of this theory
to precision electroweak data [including charged fermion masses and mixing
angles]. Finally, the predictions of the model for neutrino masses and mixing
are discussed. The most predictive version of the model naturally fits
atmospheric neutrino data with maximal $\nu_\mu \longrightarrow \nu_\tau$
oscillations and solar neutrino data with small mixing angle MSW $\nu_e
\longrightarrow \nu_{sterile}$ oscillations.


title: Factorial correlators: angular scaling within QCD jets

abstract:
  Factorial correlators measure the amount of dynamical correlation in
multiplicity between two separated phase-space windows. We present the
analytical derivation of factorial correlators for a QCD jet described at the
double logarithmic (DL) accuracy. We obtain a new angular scaling property for
properly normalized correlators between two solid-angle cells or two rings
around the jet axis. Normalized QCD factorial correlators scale with the
angular distance and are independent of the window size. Scaling violations are
expected beyond DL approximation, in particular from the subjet structure.
Experimental tests are feasible, and thus welcome.


title: Relativistic theories of interacting fields and fluids

abstract:
  We investigate divergence-type theories (DTT) describing the dissipative
interaction between a field and a fluid. We look for theories which, under
equilibrium conditions, reduce to the theory of a Klein-Gordon scalar field and
a perfect fluid. We show that the requirements of causality and positivity of
entropy production put non-trivial constarints to the structure of the
interaction terms. These theories provide a basis for the phenomonological
study of the reheating period.


title: A Matrix Approach to Numerical Solution of the DGLAP Evolution Equations

abstract:
  A matrix-based approach to numerical integration of the DGLAP evolution
equations is presented. The method arises naturally on discretisation of the
Bjorken x variable, a necessary procedure for numerical integration. Owing to
peculiar properties of the matrices involved, the resulting equations take on a
particularly simple form and may be solved in closed analytical form in the
variable t=ln(alpha_0/alpha). Such an approach affords parametrisation via data
x bins, rather than fixed functional forms. Thus, with the aid of the full
correlation matrix, appraisal of the behaviour in different x regions is
rendered more transparent and free of pollution from unphysical
cross-correlations inherent to functional parametrisations. Computationally,
the entire programme results in greater speed and stability; the matrix
representation developed is extremely compact. Moreover, since the parameter
dependence is linear, fitting is very stable and may be performed analytically
in a single pass over the data values.


title:
Implications of a possible 115 GeV supersymmetric Higgs boson on
  detection and cosmological abundance of relic neutralinos

abstract:
  We show that a supersymmetric neutral Higgs boson with a mass of about 115
GeV and with the other prerequisites required by the LEP Higgs events would be
compatible with the detection of relic neutralinos in current set-ups for WIMP
direct search. Thus this putative Higgs would fit remarkably well in an
interpretation in terms of relic neutralinos of the annual-modulation effect
recently measured in a WIMP direct experiment. We also show that the
cosmological abundance of the relevant neutralinos reaches values of
cosmological interest.


title: A Warped Supersymmetric Standard Model

abstract:
  We study the breaking of supersymmetry in five-dimensional (5d) warped
spaces, using the Randall-Sundrum model as a prototype. In particular, we
present a supersymmetry-breaking mechanism which has a geometrical origin, and
consists of imposing different boundary conditions between the fermions and
bosons living in the 5d bulk. The scale of supersymmetry breaking is
exponentially small due to the warp factor of the AdS metric. We apply this
mechanism to a supersymmetric standard model where supersymmetry breaking is
transmitted through the AdS bulk to matter fields confined on the Planck-brane.
This leads to a predictable superparticle mass spectrum where the gravitino
mass is $10^{-3}$eV and scalar particles receive masses at the one-loop level
via bulk gauge interactions. We calculate the mass spectrum in full detail
using the 5d AdS propagators. The AdS/CFT correspondence suggests that our 5d
warped model is dual to the ordinary 4d MSSM with a strongly coupled CFT sector
responsible for the breaking of supersymmetry.


title: Brane Couplings from Bulk Loops

abstract:
  We compute loop corrections to the effective action of a field theory on a
five-dimensional $S_1/Z_2$ orbifold. We find that the quantum loop effects of
interactions in the bulk produce infinite contributions that require
renormalization by four-dimensional couplings on the orbifold fixed planes.
Thus bulk couplings give rise to renormalization group running of brane
couplings.


title: Single-spin asymmetry in DVCS: fragmentation region of polarised lepton

abstract:
  For the kinematical region when a hard photon is emitted predominantly close
to the direction of motion of a longitudinally polarized initial electron and
relatively small momentum transfer to a proton we calculate the azimuthal
asymmetry of photon emission. It arises from the interference of the
Bethe-Heitler amplitude and those which are described by a heavy photon impact
factor. Azimuthal asymmetry does not decrease in the limit of infinite cms
energy. Lowest order expression for the impact factor of a heavy photon is
presented.


title: Analogue Models for T and CPT Violation in Neutral-Meson Oscillations

abstract:
  Analogue models for CP violation in neutral-meson systems are studied in a
general framework. No-go results are obtained for models in classical mechanics
that are nondissipative or that involve one-dimensional oscillators. A complete
emulation is shown to be possible for a two-dimensional oscillator with
rheonomic constraints, and an explicit example with spontaneous T and CPT
violation is presented. The results have implications for analogue models with
electrical circuits.


title: J/Psi suppression in colliding nuclei: statistical model analysis

abstract:
  We consider the $J/\Psi$ suppression at a high energy heavy ion collision. An
ideal gas of massive hadrons in thermal and chemical equilibrium is formed in
the central region. The finite-size gas expands longitudinally in accordance
with Bjorken law. The transverse expansion in a form of the rarefaction wave is
taken into account. We show that $J/\Psi$ suppression in such an environment,
when combined with the disintegration in nuclear matter, gives correct
evaluation of NA38 and NA50 data in a broad range of initial energy densities.


title: Meissner effect for color superconducting quark matter

abstract:
  The behaviour of the magnetic field inside the superconducting quark matter
core of a neutron star is investigated in the framework of the Ginzburg-Landau
theory. We take into account the simultaneous coupling of the diquark
condensate field to the usual magnetic and to the gluomagnetic gauge fields. We
solve the problem for three different physical situations: a semi-infinite
region with a planar boundary, a spherical region, and a cylindrical region. We
show that Meissner currents near the quark core boundary effectively screen the
external static magnetic field.


title:
Quantum Weakdynamics as an SU(3)_I Gauge Theory: Grand Unification of
  Strong and Electroweak Interactions

abstract:
  Quantum weakdynamics (QWD) as an SU(3)_I gauge theory with the Theta vacuum
term is considered to be the unification of the electroweak interaction as an
SU(2)_L x U(1)_Y gauge theory. The grand unification of SU(3)_I x SU(3)_C
beyond the standard model SU(3)_C x SU(2)_L x U(1)_Y is established by the
group SU(3)_I. The grand unified interactions break down to weak and strong
interactions at a new grand unification scale 10^{3} GeV, through dynamical
spontaneous symmetry breaking (DSSB); the weak and strong coupling constants
are the same, alpha_i = alpha_s ~ 0.12, at this scale. DSSB is realized by the
condensation of scalar fields, postulated to be spatially longitudinal
components of gauge bosons, instead of Higgs particles. Quark and lepton family
generation, the Weinberg angle sin^2 theta_W = 1/4, and the Cabbibo angle sin
theta_C = 1/4 are predicted. The electroweak coupling constants are alpha_z =
alpha_i/3, alpha_w = alpha_i/4, alpha_y = alpha_i/12, and alpha_e = alpha_i/16
= 1/137; there are symmetric isospin interactions.


title: CP Violation and Extra Dimensions

abstract:
  It is shown that the new sources of CP violation can be generated in the
models with more than one extra dimensions. In the supersymmetric models on the
space-time $M^4\times T^2/Z_2$, where the radius moduli have auxiliary vacuum
expectation values and the supersymmetry breaking is mediated by the
Kaluza-Klein states of gauge supermultiplets, we analyze the gaugino masses and
trilinear couplings for two scenarios and obtain that there exist relative CP
violating phases among the gaugino masses and trilinear couplings.


title: Non-Forward BFKL at Next-to-Leading Approximation

abstract:
  Representation of non-forward scattering amplitudes in the BFKL approach is
discussed and the results obtained in the next-to leading order are briefly
reviewed.


title: Virtual photon fragmentation functions

abstract:
  We introduce operator definitions for virtual photon fragmentation functions,
which are needed for reliable calculations of Drell-Yan transverse momentum
($Q_T$) distributions when $Q_T$ is much larger than the invariant mass $Q$. We
derive the evolution equations for these fragmentation functions. We calculate
the leading order evolution kernels for partons to fragment into a unpolarized
as well as a polarized virtual photon. We find that fragmentation functions to
a longitudinally polarized virtual photon are most important at small $z$, and
the fragmentation functions to a transversely polarized virtual photon dominate
the large $z$ region. We discuss the implications of this finding to the
J/$\psi$ mesons' polarization at large transverse momentum.


title: Large Lepton Mixings Induced by Sterile Neutrino

abstract:
  We assume that the mass matrix of active neutrinos has hierarchical form with
small mixings, similar to quark mass matrix. We show that the large mixings
between $\nu_\mu$ and $\nu_\tau$ as well as between $\nu_e$ and certain
combination of $\nu_\mu$ and $\nu_\tau$ required by the present data can appear
due to the presence of a sterile neutrino state. Two realizations of this
possibility are considered: (i) Large flavor mixing appears as a result of
sterile neutrino ``decoupling'' ($m_{ss} \gg m_a$), so that the active-sterile
mixings are negligible. (ii) Sterile neutrino has a mass of O(1) eV and its
mixing with active neutrinos can be observable. In the second case, the (3+1)
scheme of neutrino mass, which also accommodates the LSND result, can be
reproduced, provided the hierarchy of the mass matrix of active neutrinos is
not strong (the ratio of largest to smallest elements is about two orders of
magnitude). The enhancement of lepton mixing via coupling with sterile neutrino
can be realized in Grand Unified theories with the see-saw mechanism of
neutrino mass generation.


title: NLO parton showers and subtractive techniques

abstract:
  Motivated by asking how to combine parton showers with nonleading QCD matrix
elements, we discuss a subtractive technique based on gauge-invariant
Wilson-line operators and how this can be used to treat the soft region.


title:
Cubic Casimir operator of SU$_C$(3) and confinement in the
  nonrelativistic quark model

abstract:
  Only two-body [${\rm F}_{i} \cdot {\rm F}_{j}$] confining potentials have
been considered, thus far, in the quark model without gluons, which by
construction can only depend on the quadratic Casimir operator of the colour
SU(3) group. A three-quark potential that depends on the cubic Casimir operator
is added to the quark model. This results in improved properties of $q^3$
colour non-singlet states, which can now be arranged to have (arbitrarily)
higher energy than the singlet, and the "colour dissolution/anticonfinement"
problem of the ${\rm F}_{i} \cdot {\rm F}_{j}$ model is avoided.


title:
Three-quark exchange operators, crossing matrices and Fierz
  transformations in SU(2) and SU(3)

abstract:
  We give explicit expressions for the three-quark exchange operators, crossing
matrices and Fierz transforms for the SU(2) and SU(3) groups. We identify the
invariant terms in these operators and express them in terms of Casimir
operators.


title: Axinos as Dark Matter

abstract:
  Supersymmetric extensions of the Standard Model that incorporate the axion
solution to the strong CP problem necessarily contain also the axino, the
fermionic partner of the axion. In contrast to the neutralino and the
gravitino, the axino mass is generically not of the order of the
supersymmetry-breaking scale and can be much smaller. The axino is therefore an
intriguing candidate for a stable superpartner. In a previous Letter [1] it was
shown that axinos are a natural candidate for cold dark matter in the Universe
when they are generated non-thermally through out-of-equilibrium neutralino
decays. Here, we extend the study of non-thermal production and include a
competing thermal production mechanism through scatterings and decays of
particles in the plasma. We identify axino masses in the range of tens of MeV
to several GeV (depending on the scenario) as corresponding to cold axino
relics if the reheating temperature $\treh$ is less than about
$5\times10^4\gev$. At higher $\treh$ and lower mass, axinos could constitute
warm dark matter. In the scenario with axinos as relics, the gravitino problem
finds a natural solution. The lightest superpartner of the Standard Model
spectrum remains effectively stable in high-energy detectors but may be either
neutral or charged. The usual highly restrictive constraint $\abundchi\lsim1$
on the relic abundance of the lightest neutralino becomes void.


title: Hadronic Loop Corrections to the Muon Anomalous Magnetic Moment

abstract:
  The dominant theoretical uncertainties in both, the anomalous magnetic moment
of the muon and the value of the electromagnetic coupling at the Z scale arise
from their hadronic contributions. Since these will ultimately dominate the
experimental errors, we study the correlation between them, as well as with
other fundamental parameters. To this end we present analytical formulas for
the QCD contribution from higher energies and from heavy quarks. Including
these correlations affects the Higgs boson mass extracted from precision data.


title: Regularization for effective field theory with two heavy particles

abstract:
  A regularization for effective field theory with two propagating heavy
particles is constructed. This regularization preserves the low-energy analytic
structure, implements a low-energy power counting for the one-loop diagrams,
and preserves symmetries respected by dimensional regularization.


title: On the heavy monopole potential in gluodynamics

abstract:
  We discuss predictions for the interaction energy of the fundamental
monopoles in gluodynamics introduced via the 't Hooft loop. At short distances,
the heavy monopole potential is calculable from first principles. At larger
distances, we apply the Abelian dominance models. We discuss the measurements
which would be crucial to distinguish between various models. Non-zero
temperatures are also considered. Our predictions are in qualitative agreement
with the existing lattice data.


title: Neutrino oscillations in matter of varying density

abstract:
  We consider two-family neutrino oscillations in a medium of
continuously-varying density as a limit of the process in a series of
constant-density layers. We construct analytic expressions for the conversion
amplitude at high energies within a medium with a density profile that is
piecewise linear. We compare some cases to understand the type of effects that
depend on the order of the material traversed by a neutrino beam.


title:
Possible LSND effect as a small perturbation of the bimaximal texture
  for three active neutrinos

abstract:
  A particular form of mixing matrix for three active and one sterile neutrinos
is proposed. Its $3\times 3 $ part describing three active neutrinos arises
from the popular bimaximal mixing matrix that works satisfactorily in solar and
atmospheric experiments if the LSND effect is ignored. Then, the sterile
neutrino, effective in the fourth row and fourth column of the proposed mixing
matrix, is responsible for the possible LSND effect by inducing one extra
neutrino mass state to exist actively. The LSND effect, if it exists, turns out
to reveal its {\it perturbative} nature related to small mixing of three active
neutrinos with their sterile partner.


title: The Cosmological Constant and the Brane World Scenario

abstract:
  Although the cosmological constant has primarily cosmological consequences,
its smallness poses one of the basic problems in particle physics. Various
attempts have been made to explain this mystery, but no satisfactory solution
has been found yet. The appearance of extra dimensions in the framework of
brane world systems seems to provide some new ideas to address this problem
form a different point of view. We shall discuss some of these new approaches
and see whether or not they lead to an improvement of the situation. We shall
conclude that we are still far from a solution of the problem.


title: Correlations and fluctuations - Introduction

abstract:
  A rewiew of the development of formalism to describe correlations and
fluctuations in multiparticle production is presented. The milestones of
history of this development and some obvious sources of correlations in
experimental data are recalled. Some recent subjects concerning the
correlations are shortly discussed.


title:
Electric Dipole moments of charged leptons and lepton flavor violating
  interactions in the general two Higgs Doublet model

abstract:
  We calculate the electric dipole moment of electron using the experimental
result of muon electric dipole moment and upper limit of the BR(\mu -->
e\gamma) in the framework of the general two Higgs doublet model. Our
prediction is 10^{-32} e-cm, which lies in the experimental current limits.
Further, we obtain constraints for the Yukawa couplings \bar{\xi}^{D}_{N,\tau
e} and \bar{\xi}^{D}_{N,\tau\mu}. Finally we present an expression which
connects the BR(\tau\to \mu\gamma) and the electric dipole moment of
\tau-lepton and study the relation between these physical quantities.


title:
Z scaling, fractality, and principles of relativity in the interactions
  of hadrons and nuclei at high energies

abstract:
  The formation length of particles produced in the relativistic collisions of
hadrons and nuclei has relevance to fundamental principles of physics at small
interaction distances. The relation is expressed by z scaling observed in the
differential cross sections for the inclusive reactions at high energies. The
scaling variable reflects the length of the elementary particle trajectory in
terms of a fractal measure. Characterizing the fractal approach, we demonstrate
the relativity principles in space with broken isotropy. We derive relativistic
transformations accounting for asymmetry of space-time expressed by different
anomalous fractal dimensions of the interacting objects.


title:
Searching for Supersymmetric Dark Matter - The Directional Rate and the
  Modulation Effect Due to Caustic Rings

abstract:
  The detection of the theoretically expected dark matter is central to
particle physics and cosmology. Current fashionable supersymmetric models
provide a natural dark matter candidate which is the lightest supersymmetric
particle (LSP). The allowed parameter space of such models combined with fairly
well understood physics (quark substructure of the nucleon and nuclear
structure) permit the evaluation of the event rate for LSP-nucleus elastic
scattering. The thus obtained event rates, which sensitively depend on the
allowed parameter space parameters, are usually very low or even undetectable.
  So, for background reduction, one would like to exploit two nice features of
the reaction, the directional rate, which depends on the sun's direction of
motion and the modulation effect, i.e. the dependence of the event rate on the
earth's annual motion. In the present paper we study these phenomena in a
specific class of non isothermal models, which take into account the late
in-fall of dark matter into our galaxy, producing flows of caustic rings. We
find that the modulation effect arising from such models is smaller than that
found previously with isothermal symmetric velocity distributions and much
smaller compared to that obtained using a realistic asymmetric distribution
with enhanced dispersion in the galactocentric direction.


title: Neutralino Proton Cross Section and Dark Matter Detection

abstract:
  We consider the neutralino proton cross section for detection of Milky Way
dark matter for a number of supergravity models with gauge unification at the
GUT scale: models with universal soft breaking (mSUGRA), models with
nonuniversal soft breaking, and string inspired D-brane models. The parameter
space examined includes m_{1/2}<1 TeV and tan \beta < 50, and the recent Higgs
bound of m_h >114 GeV is imposed. (For grand unified models, this bound is to
be imposed for all tan \beta.) All coannihilation effects are included as well
as the recent NLO corrections to b\to s\gamma for large tan \beta, and
coannihilation effects are shown to be sensitive to A_0 for large tan \beta. In
all models, current detectors are sampling parts of the paramater space i. e.
tan \beta >~ 25 for mSUGRA, tan \beta >~ 7 for nonuniversal models, and tan
\beta>~ 20 for D-brane models. Future detectors should be able to cover almost
the full parameter space for \mu > 0. For \mu< 0, cancellations can occur for
m_{1/2} >~ 450 GeV, allowing the cross sections to become ~< 10^{-10} pb for
limited ranges of tan\beta. (The positions of these cancellations are seen to
be sensitive to the value of \sigma_{\pi N}.) In this case, the gluino and
squarks lie above 1 TeV, but still should be accessible to the LHC if m_{1/2}
<1 TeV.


title: Solving the Hierarchy Problem with Brane Crystals

abstract:
  The brane world scenario advocated by Arkani-Hamed et al. transmutes the
hierarchy problem into explaining why extra dimensions have sizes much larger
than the fundamental scale. In this paper we discuss possible solutions to this
problem by considering the compactified dimensions to be populated by a large
number of branes in a crystal lattice. The experimental consequences of this
scenario are described, including the presence of large energy gaps in the
spectrum of Kaluza-Klein modes.


title:
Survival Probability of Large Rapidity Gaps in pbar p, pp, gamma p and
  gamma gamma Collisions

abstract:
  Using an eikonal analysis, we simultaneously fit a QCD-inspired
parameterization of all accelerator data on forward proton-proton and
antiproton-proton scattering amplitudes, together with cosmic ray data (using
Glauber theory), to predict proton-air and proton-proton cross sections at
energies near \sqrt s \approx 30 TeV. The p-air cosmic ray measurements greatly
reduce the errors in the high energy proton-proton and proton-air cross section
predictions--in turn, greatly reducing the errors in the fit parameters. From
this analysis, we can then compute the survival probability of rapidity gaps in
high energy pbar p and pp collisions, with high accuracy in a quasi model-free
environment. Using an additive quark model and vector meson dominance, we note
that that the survival probabilities are identical, at the same energy, for
gamma p and gamma gamma collisions, as well as for nucleon-nucleon collisions.
Significantly, our analysis finds large values for gap survival probabilities,
\approx 30% at \sqrt s = 200 GeV, \approx 21% at \sqrt s = 1.8 TeV and \approx
%%13% at \sqrt s = 14 TeV.


title:
The Semileptonic Decays $B\to\pi l\nu$ and $D\to\pi l\nu$ from Lattice
  QCD

abstract:
  We present a lattice QCD calculation of the form factors and differential
decay rates for semileptonic decays of the heavy-light mesons $B$ and $D$ to
the final state $\pi l\nu$. The results are obtained with three methodological
improvements over previous lattice calculations: a matching procedure that
reduces heavy-quark lattice artifacts, the first study of lattice-spacing
dependence, and the introduction of kinematic cuts to reduce model dependence.
We show that the main systematics are controllable (within the quenched
approximation) and outline how the calculations could be improved to aid
current experiments in the determination of~$|V_{ub}|$ and~$|V_{cd}|$.


title:
Analysis of the nature of the $\phi\to\gamma\pi\eta$ and
  $\phi\to\gamma\pi^0\pi^0$ decays

abstract:
  We study interference patterns in the $\phi\to(\gamma
a_0+\pi^0\rho)\to\gamma\pi\eta$ and $\phi\to(\gamma f_0+\pi^0\rho)\to\gamma
\pi^0\pi^0$ reactions. Taking into account the interference, we fit the
experimental data and show that the background reaction does not distort the
$\pi^0\eta$ spectrum in the decay $\phi\to\gamma\pi\eta$ everywhere over the
energy region and does not distort the $\pi^0\pi^0$ spectrum in the decay
$\phi\to\gamma\pi^0\pi^0$ in the wide region of the $\pi^0\pi^0$ system
invariant mass, $m_{\pi\pi}>670$ MeV, or when the photon energy is less than
300 MeV. We discuss the details of the scalar meson production in the radiative
decays and note that there are reasonable arguments in favor of the one-loop
mechanism $\phi\to K^+K^-\to\gamma a_0$ and $\phi\to K^+K^-\to\gamma f_0$. We
discuss also distinctions between the four-quark, molecular, and two-quark
models and argue that the Novosibirsk data give evidence in favor of the
four-quark nature of the scalar $a_0(980)$ and $f_0(980)$ mesons.


title: Aspects of Color Superconductivity

abstract:
  I discuss some aspects of recent developments in color superconductivity in
high density quark matter. I calculate the Cooper pair gap and the critical
points at high density, where magnetic gluons are not screened. The ground
state of high density QCD with three light flavors is shown to be a
color-flavor locking state, which can be mapped into the low-density hadronic
phase. The meson mass at the CFL superconductor is also calculated. The CFL
color superconductor is bosonized, where the Fermi sea is identified as a
$Q$-matter and the gapped quarks as topological excitations, called
superqualitons, of mesons. Finally, as an application of color
supercoductivity, I discuss the neutrino interactions in the CFL color
superconductor.


title: Axino as a sterile neutrino and R parity violation

abstract:
  We point out that axino can be a natural candidate for sterile neutrino which
would accommodate the LSND data with atmospheric and solar neutrino
oscillations. It is shown that the so called 3+1 scheme can be easily realized
when supersymmetry breaking is mediated by gauge interactions and also R-parity
is properly broken. Among the currently possible solutions to the solar
neutrino problem, only the large angle MSW oscillation is allowed in this
scheme. The weak scale value of the Higgs $\mu$ parameter and the required size
of R-parity violation can be understood by means of spontaneously broken
Peccei-Quinn symmetry.


title: Intrinsic quadrupole moment of the nucleon

abstract:
  We address the question of the intrinsic quadrupole moment Q_0 of the nucleon
in various models. All models give a positive intrinsic quadrupole moment for
the proton. This corresponds to a prolate deformation. We also calculate the
intrinsic quadrupole moment of the Delta(1232). All our models lead to a
negative intrinsic quadrupole moment of the Delta corresponding to an oblate
deformation.


title: The glueball Regge trajectory from the string-inspired theory

abstract:
  The special case of 4D string-like theory proposed early is investigated.
Regge trajectories in the developed model are non-linear for small masses and
the values of spin and have the different asymptotical slopes $\alpha_p$. The
value $\alpha_p$ just as the form of the trajectory depends from the quantum
state of some ''internal'' {relativistic invariant} variables. It is also shown
that some trajectories have the asymptotical slope $\alpha_g$=0.21 $Gev^{-2}$.


title: Why Photon Colliders are necessary in a future collider program

abstract:
  Subjects of discussion
  Different scenarios
  Higgs window to a New Physics
  Anomalies in the interactions of gauge and Higgs bosons
  Some problems with t-quarks and MSSM.
  Some problems in QCD and hadron physics.
  By-product: Production of axions, etc. from region of conversion e --> gamma.


title:
Complete analysis of pion-nucleon scattering in chiral perturbation
  theory to third order

abstract:
  We consider pion-nucleon scattering in heavy-baryon chiral perturbation
theory to third order. All electromagnetic corrections appearing to this order
are included. We thus have a consistent description of strong and
electromagnetic effects, which allows us to isolate the strong part of the
interaction in an unambiguous way. We give pion-nucleon phase shifts up to pion
laboratory momenta of 100 MeV and find sizeable differences for the S-waves of
the elastic channels compared to previous phase shift analyses. The precise
description of the scattering process also allows us to address the question of
isospin violation in the strong interaction. For the usually employed triangle
relation we find an isospin breaking effect of -0.7% in the S-wave, whereas the
P-waves show an effect of -1.5% and -4 to -2.5%, respectively, for pion
laboratory momenta between 25 and 100 MeV.


title: Analyticity and power corrections in hard-scattering hadronic functions

abstract:
  Demanding the analyticity of hadronic observables (calculated in terms of
power series of the running coupling) as a {\it whole}, we show that they are
free of the Landau singularity. Employing resummation and dispersion-relation
techniques, we compute in a unifying way power corrections to two different
hard-scattering functions in perturbative QCD: the electromagnetic pion form
factor to leading order and the inclusive cross section of the Drell-Yan
process. In the second case, the leading nonperturbative power correction in
$b\Lambda_{\rm QCD}$ gives rise to a Sudakov-like exponential factor in the
impact parameter space which provides enhancement rather than suppression.


title:
Uncertainties of predictions from parton distribution functions II: the
  Hessian method

abstract:
  We develop a general method to quantify the uncertainties of parton
distribution functions and their physical predictions, with emphasis on
incorporating all relevant experimental constraints. The method uses the
Hessian formalism to study an effective chi-squared function that quantifies
the fit between theory and experiment. Key ingredients are a recently developed
iterative procedure to calculate the Hessian matrix in the difficult global
analysis environment, and the use of parameters defined as components along
appropriately normalized eigenvectors. The result is a set of 2d Eigenvector
Basis parton distributions (where d=16 is the number of parton parameters) from
which the uncertainty on any physical quantity due to the uncertainty in parton
distributions can be calculated. We illustrate the method by applying it to
calculate uncertainties of gluon and quark distribution functions, W boson
rapidity distributions, and the correlation between W and Z production cross
sections.


title: CP Violation: Past, Present, and Future

abstract:
  We discuss the history of CP violation and its manifestations in kaon
physics, its explanation in terms of phases of the Cabibbo-Kobayashi-Maskawa
matrix describing charge-changing weak quark transitions, predictions for
experiments involving $B$ mesons, and the light it can shed on physics beyond
the Standard Model.


title:
New Bounds on Slepton and Wino Masses in Anomaly Mediated Supersymmetry
  Breaking Models

abstract:
  We show how the spectrum of the minimal anomaly-mediated supersymmetry
breaking model can be constrained from the condition that the electroweak
symmetry breaking minimum of the scalar potential is the deepest point in the
field space. Applying the current experimental bounds and scanning over the
whole parameter space, we rule out selectrons below 378 GeV and staus below 269
GeV, the numbers having a modest uncertainty. We also find a new upper bound on
the wino-like chargino mass for a given slepton mass. This rules out the
possibility of slepton pair production at ongoing or upcoming colliders like
the Tevatron or the Next Linear Collider at $\sqrt{s}=500$ GeV, where pair
production of charginos may be the only available signal.


title:
Scenario of Light Sterile Neutrinos with A Heavy Tau Neutrino in A
  Supersymmetric Model

abstract:
  Three light sterile neutrinos (\nu_e^s, \nu_\mu^s and \nu_\tau^s) are
introduced to accommodate all the available neutrino data: the atmospheric
neutrino anomaly is explained by \nu_\mu-\nu_\mu^s oscillation with maximal
mixing; the solar one is due to \nu_e-\nu_e^s oscillation of small angle
Mikheyev-Smirnov-Wolfenstein type; the Liquid Scintillation Neutrino Detector
data is from \nu_e -\nu_\mu oscillations, so that the neutrinos can be the hot
component of the dark matter. The big bang nucleosynthesis constraint is
satisfied by taking the tau neutrino to be 10 MeV heavy. The \nu_\tau decay is
discussed in a model of gauge mediated supersymmetry breaking. The decay mode
\nu_\tau\to\tilde{G}\gamma with \tilde{G} being the gravitino is proposed. The
\nu_\tau has a rather long lifetime \sim 10^3-10^{13} sec. Its implication to
the Gamma-ray Burst is discussed.


title:
Evolution of the quark-gluon and hadronic fluid with the compressible
  bag model

abstract:
  The evolution of matter produced in nucleus collisions is investigated in the
frame work of the simplified fluid equation, where the compressible bag model
is used as the equation of state for hadrons. It is shown that the quark-gluon
phase is easily achieved in RHIC experiments, and that the typical structure of
the phase transition, however, may be difficult to observe in simple analyses
of $<p_t>$ data.


title: Unitarized ChPT Amplitudes and Crossing Symmetry Violation

abstract:
  Pion-pion scattering amplitude obtained from one-loop Chiral Perturbation
Theory (ChPT) is crossing symmetric, however the corresponding partial-wave
amplitudes do not respect exact unitarity relation. There are different
approaches to get unitarized results from ChPT. Here we consider the inverse
amplitude method (IAM) and, using the Roskies relations, we measure the amount
of crossing symmetry violation when IAM is used in order to fit pion-pion
phase-shifts to experimental data in the resonance region. We also show the
unitarity violation of the crossing symmetric ChPT amplitude with its
parameters fixed in order to fit to experimental phase-shifts.


title: PT - symmetrized supersymmetric quantum mechanics

abstract:
  Supersymmetry between bosons and fermions is modeled within PT- symmetric
quantum mechanics. A non-Hermitian alternative to the Witten's supersymmetric
quantum mechanics is obtained.


title:
Phenomenology of neutrino physics in the Kaluza-Klein theories of low
  scale gravity

abstract:
  We discuss the phenomenological consequences of theories which describe
sterile neutrinos in large extra dimensions. We show that the Kaluza-Klein
tower of the singlet neutrinos, albeit tiny individual contribution in
electroweak processes, act cumulatively, giving rise to non-universality of the
weak interactions of the light neutrinos and to flavour-violating radiative
processes. Owing to these non-decoupling effects of th Kaluza--Klein neutrinos,
we derive strong constraints on the parameters of the theory that originates
from the non-observation of flavour-violating and universality-breaking
phenomena. In this theory we propose a four-neutrino model which can reconcile
the existing data coming from underground experiments in terms of neutrino
oscillations, together with the hint from the LSND experiment and a possible
neutrino contribution to the hot dark matter of the Universe.


title: The chicken or the egg; or Who ordered the chiral phase transition?

abstract:
  We draw an analogy between the deconfining transition in the 2+1 dimensional
Georgi-Glashow model and the chiral phase transition in 3+1 dimensional QCD.
Based on the detailed analysis of the former (hep-th/0010201) we suggest that
the chiral symmetry restoration in QCD at high temperature is driven by the
thermal ensemble of baryons and anti-baryons. The chiral symmetry is restored
when roughly half of the volume is occupied by the baryons. Surprisingly
enough, even though baryons are rather heavy, a crude estimate for the critical
temperature gives $T_c=180$ Mev. In this scenario the binding of the instantons
is not the cause but rather a consequence of the chiral symmetry restoration.


title: Nuclear Effects in Prompt Photon Production at the Large Hadron Collider

abstract:
  We present a detailed study of prompt photon production cross section in
heavy-ion collisions in the central rapidity region at energy of $\sqrt{s}=5.5$
TeV, appropriate to LHC experiment. We include the next-to-leading order
radiative corrections, $O(\alpha_{em}\alpha_s^2)$, nuclear shadowing and the
parton energy loss effects. We find that the nuclear effects can reduce the
invariant cross section for prompt photon production by an order of magnitude
at $p_t=3$ GeV. We discuss theoretical uncertainties due to parton energy loss
and nuclear shadowing parameters. We show that the K-factor, which signifies
the importance of next-to-leading order corrections, is large and has a strong
$p_t$ dependence.


title: High-Energy QCD and Wilson Lines

abstract:
  At high energies the particles move very fast so their trajectories can be
approximated by straight lines collinear to their velocities. The proper
degrees of freedom for the fast gluons moving along the straight lines are the
Wilson-line operators -- infinite gauge factors ordered along the straight
line. I review the study of the high-energy scattering in terms of Wilson-line
degrees of freedom.


title: Neutrinos, Large Extra Dimensions and Solar Neutrino Puzzle

abstract:
  A desirable feature of models with large extra dimensions and a TeV range
string scale is the possibility to understand an ultralight sterile neutrino
needed for a simultaneous understanding of solar, atmospheric and LSND results
as a Kaluza-Klein state of a bulk neutrino. How these oscillation data are
understood in quantitative detail is still not clear. We have recently
suggested a new way to understand the solar neutrino data in this framework by
a combination of vacuum and small angle MSW transition of $\nu_e$ to sterile KK
modes of the bulk neutrino. This mechanism can be embedded into an economical
extension of the standard model in the brane to understand the atmospheric and
LSND data. After a brief discussion of how small neutrino masses arise
naturally in extra dimensional models, we review this new suggestion.


title:
The Shape and Experimental Tests of the Q^2-Invariant Polarized Gluon
  Asymmetry

abstract:
  The absence of "valence-gluon" degrees of freedom combined with an
examination of radiative QCD diagrams leads to an implication that the gluon
spin asymmetry in a proton, defined as A_G(x,Q^2) = (Delta G)/G, should be
approximately Q^2 invariant. The condition for scale invariance completely
determines the x-dependence of this asymmetry, which satisfies the constituent
counting rules and reproduces the basic results of the Bremsstrahlung model
originated by Close and Sivers. This asymmetry can be combined with the
measured unpolarized gluon density, G(x,Q^2) to provide a prediction for Delta
G(x,Q^2). Existing and proposed experiments can test both the prediction of
scale invariance for A_G and the nature of Delta G itself.


title: Rare radiative B decays in perturbative QCD

abstract:
  We report on recent progress on perturbative QCD calculations of certain
exclusive rare weak $B$ meson decays involving hard photons. In the limit of a
photon energy $E_\gamma$ much larger than $\Lambda_{QCD}$, the amplitudes for
such processes can be analyzed in a twist expansion in powers of
$\Lambda/E_\gamma$. The leading twist amplitude is given by the convolution of
a hard scattering amplitude with the $B$ meson light-cone wavefunction. This
approach is applied to a calculation of the leptonic radiative $B\to \gamma
\ell \nu_\ell$ formfactors and to an estimate of the weak annihilation
contribution to the penguin decays $B\to \rho(\omega)\gamma$. As an application
we discuss a few methods for constraining the unitarity triangle with exclusive
radiative B decays.


title:
Solving the mu problem in gauge mediated supersymmetry breaking models
  with flavor symmetry

abstract:
  We suggest a solution to the \mu problem of gauge mediated supersymmtery
breaking models based on flavor symmetries. In this scenario the \mu term
arises through the vacuum expectation value of a singlet scalar field which is
suppressed by a flavor symmetry factor relative to the scale of dynamical SUSY
breaking. The same flavor symmetry also ensures that the soft SUSY breaking
parameter B\mu is not much larger than \mu^2, a necessary condition for the
stability of electroweak symmetry breaking. Explicit examples where B\mu ~
\mu^2 and B\mu << \mu^2 are presented. The latter case provides a natural
solution to the supersymmetric CP problem. We show that the same flavor
symmetry that suppresses the \mu and the B\mu parameters can also play a role
in explaining the fermion mass and mixing hierarchy puzzle.


title: Strangeness Production by Electromagnetic and Hadronic Probes

abstract:
  After pioneering works on hypernuclei, strangeness production mechanisms have
been studied in hadron collisions and photoreactions in the sixties. Recent
experiments at SATURNE and COSY, in the hadronic sector, as well as ELSA and
JLab, in the electromagnetic sector, have confirmed our basic ideas on the
reaction mechanisms. In the near future, strangeness production at JLab, HERMES
and COMPASS may prove to be a powerful tool to study hadronic matter.


title:
New Limits on Doubly Charged Bileptons from CERN LEP Data and the Search
  at Future Electron-Positron and Electron-Photon Colliders

abstract:
  We show that the accumulated LEP-II data taken at $\sqrt{s} =$ 130 to 206 GeV
can establish more restrictive bounds on doubly charged bileptons couplings and
masses than any other experiment so far. We also analyze the discovery
potential of a prospective linear collider operating in both $e^+ e^-$ and $e
\gamma$ modes.


title: Affinity for Scalar Fields to Dissipate

abstract:
  The zero temperature effective equation of motion is derived for a scalar
field interacting with other fields. For a broad range of cases, involving
interaction with as few as one or two fields, dissipative regimes are found for
the scalar field system. The zero temperature limit constitutes a baseline
effect that will be prevalent in any general statistical state. Thus, the
results found here provide strong evidence that dissipation is the norm not
exception for an interacting scalar field system. For application to
inflationary cosmology, this provides convincing evidence that warm inflation
could be a natural dynamics once proper treatment of interactions is done. The
results found here also may have applicability to entropy production during the
chiral phase transition in heavy ion collision.

categories: hep-ph astro-ph cond-mat.soft gr-qc hep-th


title:
Lattice measurement of the scalar propagator near the symmetry breaking
  phase transition

abstract:
  Recent lattice simulations of $(\lambda \Phi^4)_4$ theories in the broken
phase show that : a) the shifted field propagator is well reproduced by the
simple 2-parameter form ${{Z_{\rm prop}}\over{p^2 + M^2_h}}$ at finite momenta
but strongly differs for $p \to 0$ b) the bare zero-momentum two-point function
$\Gamma_2(0)= \frac{d^2 V_{\rm eff}}{d \phi^2_B}|_{\phi_B= \pm v_B}$ gives a
value of $Z_\phi \equiv {{M^2_h}\over{\Gamma_2(0)}}$ that increases when
approaching the continuum limit. This supports theoretical expectations where
$v_B$ is related by an infinite re-scaling to the `physical Higgs condensate'
$v_R$ defined through $\frac{d^2 V_{\rm eff}}{d \phi^2_R}|_{\phi_R= \pm
v_R}=M^2_h$. New lattice data collected around the phase transition confirm
this scenario. By denoting $M_{\rm SB} \equiv M_h ={\cal O} (v_R)$ the scale of
the broken phase, our results suggest the existence of a `hierarchy' of scales
$\Gamma_2(0) \ll M^2_{\rm SB} \ll v^2_B$ that become infinitely far in the
continuum limit. This may open unexpected possibilities to reconcile an
infinitesimal slope of the effective potential with finite values of $M_h$ and
accomodate very different mass scales in the framework of a spontaneously
broken theory.


title:
Uncertainties of Predictions from Parton Distribution Functions I: the
  Lagrange Multiplier Method

abstract:
  We apply the Lagrange Multiplier method to study the uncertainties of
physical predictions due to the uncertainties of parton distribution functions
(PDFs), using the cross section for W production at a hadron collider as an
archetypal example. An effective chi-squared function based on the CTEQ global
QCD analysis is used to generate a series of PDFs, each of which represents the
best fit to the global data for some specified value of the cross section. By
analyzing the likelihood of these "alterative hypotheses", using available
information on errors from the individual experiments, we estimate that the
fractional uncertainty of the cross section due to current experimental input
to the PDF analysis is approximately 4% at the Tevatron, and 8-10% at the LHC.
We give sets of PDFs corresponding to these up and down variations of the cross
section. We also present similar results on Z production at the colliders. Our
method can be applied to any combination of physical variables in precision QCD
phenomenology, and it can be used to generate benchmarks for testing the
accuracy of approximate methods based on the error matrix.


title: Dissipation, noise and vacuum decay in quantum field theory

abstract:
  We study the process of vacuum decay in quantum field theory focusing on the
stochastic aspects of the interaction between long and short-wavelength modes.
This interaction results in a diffusive behavior of the reduced Wigner function
describing the state of the long-wavelength modes, and thereby to a finite
activation rate even at zero temperature. This effect can make a substantial
contribution to the total decay rate.


title:
Pion Form Factor and Quark Mass Evolution in a Light-Front
  Bethe-Salpeter Model

abstract:
  We discuss the soft contribution to the elastic pion form factor with the
mass evolution from current to constituent quark being taken into account using
a light-front Bethe-Salpeter (LFBS) model, which is a light-front quark model
(LFQM) with a running mass. It is shown that partial conservation of the
axial-vector current (PCAC) is satisfied with a running quark mass. We examine
the sensitivity of the pion form factor using two different functional forms of
the quark propagator. The Ball-Chiu ansatz is used to maintain local gauge
invariance of the quark-photon vertex. The extension of our model to the hard
contribution is also discussed.


title: Instabilities in neutrino-plasma density waves

abstract:
  One examines the interaction and possible resonances between supernova
neutrinos and electron plasma waves. The neutrino phase space distribution and
its boundary regions are analyzed in detail. It is shown that the boundary
regions are too wide to produce non-linear resonant effects. The growth or
damping rates induced by neutrinos are always proportional to the neutrino flux
and $G_{{\rm F}}^{2}$.


title: SU(3) Chiral Symmetry in Non-Relativistic Field Theory

abstract:
  Applications imposing SU(3) chiral symmetry on non-relativistic field theory
are considered. The first example is a calculation of the self-energy shifts of
the spin-3/2 decuplet baryons in nuclear matter, from the chiral effective
Lagrangian coupling octet and decuplet baryon fields. Special attention is paid
to the self-energy of the delta baryon near the saturation density of nuclear
matter. We find contributions to the mass shifts from contact terms in the
effective Lagrangian with coefficients of unknown value. As a second
application, we formulate an effecive field theory with manifest SU(2) chiral
symmetry for the interactions of K and eta mesons with pions at low energy.
SU(3) chiral symmetry is imposed on the effective field theory by a matching
calculation onto three-flavor chiral perturbation theory. The effective
Lagrangian for the pi-K and pi-eta sectors is worked out to order Q^4; the
effective Lagrangian for the K-K sector is worked out to order Q^2 with contact
interactions to order Q^4. As an application of the method, we calculate the KK
s-wave scattering phase shift at leading order and compare with chiral
perturbation theory. We conclude with a discussion of the limitations of the
approach and propose new directions for work where the matching calculation may
be useful.


title: Heavy meson masses via Dick interquark potential

abstract:
  We study Dick quark-antiquark potential (up to a color factor)
$V_D(r)={-\alpha_s \over r} + gf \sqrt{N_c \over {2(N_c-1)}} \ln[exp(2mr)-1]$
in the heavy meson sector. This potential emerges from an effective
dilaton-gluon coupling inspired from string theory and proves to be linearly
rising at large distances which ensures quark confinement. The
semi-relativistic wave equation which appears in the theory of relativistic
quark-antiquark bound states is used. This equation is cast into a constituent
second order Schr\"{o}dinger-like equation with the inclusion of relativistic
corrections up to order $(v/c)^{2}$ in the quark speeds. The resulting equation
is solved for Dick potential via the Shifted-$l$ expansion technique (SLET).
The obtained results show that the spin-averaged energy levels of heavy-mesons
are well explained and agree with other potential models or QCD sum rules
predictions. Moreover, as a by-product, our analysis assign to the dilaton a
mass around 56.9 MeV lying within the range of many theoretical scenario of
dilatonic mass.


title: Old and new parton distribution and fragmentation functions

abstract:
  A short review of problems with parton distribution functions in nucleons,
non-polarized and polarized, is given. The main part is devoted to the
transversity distribution its possible measurement and its first experimental
probe via spin asymmetry in semi-inclusive DIS. It is argued that the proton
transversity distribution could be successfully measured in future DIS
experiments with {\it longitudinally} polarized target.


title: On the large-s behavior of total cross sections in perturbative QCD

abstract:
  Reported is a factorization theorem for large-s behavior of total cross
sections obtained in a straightforward fashion from ordinary perturbation
theory. The theorem extends the standard factorization results for the Bjorken
and Drell-Yan processes. The obtaining of useful evolution equations is found
to be problematic. A by-product is a direct method for systematic calculations
of the parton evolution kernels.


title: The skewed quark distribution of the pion at large momentum transfer

abstract:
  We derive an explicit and model-independent representation for the skewed
quark distribution of the pion in the limit of large momentum transfer. Our
result is expressed in terms of the conventional pion distribution amplitudes
and complies with known properties of skewed parton distributions such as
symmetry and polynomiality conditions. The continuity of the result at the
points \pm \xi is manifest, whereas its derivatives exhibit discontinuities.


title:
An Inclusive Cross Section for the Nucleus - Nucleus Interaction at RHIC
  Energies

abstract:
  We discuss the saturation of the parton density in heavy ion collisions at
RHIC energiesusing a Pomeron approach. Our predictions for the particle density
in ion-ion collisions at RHIC energies can be utilized as the background for
the observation of possible quark-gluon plasma production.


title: Do Instantons and Strings Cluster when the Number of Colors is Large?

abstract:
  We consider the $N_c\to\infty$ limit of QCD using a toy model in which
instantons exchange color-singlet scalar fields which do not self-interact. Our
main observation is that collective attraction leads the formation of large
clusters containing $O(N_c)$ nonperturbative objects. We further show that this
clustering of instantons is limited due to a non-trivial repulsion inherent in
the ADHM multi-instanton solution. As a result the vacuum is very different
from that at low $N_c$, notably being more inhomogeneous, in ways which will
affect chiral symmetry breaking of light quarks. We also briefly discuss a
similar phenomenon for color strings in baryons made of medium-mass
(charm-like) quarks.


title: Further comment on pion electroproduction and the axial form factor

abstract:
  We show that a recent claim (H.Haberzettl, Phys. Rev. Lett. 85 (2000) 3576)
that one cannot extract the nucleon weak axial form factor G_A (t) from charged
pion threshold electroproduction is incorrect. Thus previous calculations
remain valid and threshold charged pion electroproduction experiments can
indeed be used to determine G_A (t), and they should certainly be pursued.


title:
Massive constituent quarks and unified description of freeze-out
  parameters: does QGP form at low temperature?

abstract:
  The possibility of unified description of hadron multiple production in heavy
ion collisions over the wide energy interval, from few hundreds MeV/n at
GSI/SIS through 11 GeV/n at BNL/AGS up to 160 GeV/n at CERN/SPS, has been
emphasized recently by J. Cleymans and K. Redlich. They, and somewhat later B.
Muller and J. Rafelski, treated this fact as an indication that quark-gluon
plasma (QGP) can be produced even at very low energies of impinging nuclei. In
our opinion, it rather witnesses that a massive constituent quark (valon) - not
massless current quark and gluon! - is just what becomes "quite easily" to be
unbound, and thus supports the expectation that in course of compression and
heating from hadronic state to QGP (or, vice versa, of expansion and cooling
down from QGP to hadronic state) nuclear matter should pass through an
intermediate phase in between.


title: Long-Range Interactions of the Ball

abstract:
  In model independent way considered long-range interactions of the
macroscopic objects under assumption that any particle of this objects interact
with probe particle as $ A/r^n$. Also presented model-independent corrections
to the Coulomb energy levels from regularised version of the potential $
A/r^n$.


title: Fixed-Point Hamiltonians in Quantum Mechanics

abstract:
  We show how to derive fixed-point Hamiltonians in quantum mechanics from a
proposed renormalization group invariance approach that relies in a subtraction
procedure at a given energy scale. The scheme is valid for arbitrary
interactions that originally contain point-like singularities (as the
Dirac-delta and/or its derivatives). One example of diagonalization of a
fixed-point Hamiltonian illustrates the procedure for an interaction that
contains regular and singular parts. In another example, the fixed point
Hamiltonian is derived for the case of higher order singularities in the
interaction.


title: Rare B -> K^* (nu) bar(nu) decay beyond standard model

abstract:
  Using the most general, model-independent form of effective Hamiltonian, the
exclusive, rare $B \rar K^\ast \nu \bar \nu$ decay is analyzed. The sensitivity
of the branching ratios and missing mass-squared spectrum to the new Wilson
coefficients is discussed.


title: A Diagrammatic Approach to Crystalline Color Superconductivity

abstract:
  We present a derivation of the gap equation for the crystalline color
superconducting phase of QCD which begins from a one-loop Schwinger-Dyson
equation written using a Nambu-Gorkov propagator modified to describe the
spatially varying condensate. Some aspects of previous variational calculations
become more straightforward when rephrased beginning from a diagrammatic
starting point. This derivation also provides a natural base from which to
generalize the analysis to include quark masses, nontrivial crystal structures,
gluon propagation at asymptotic densities, and nonzero temperature. In this
paper, we analyze the effects of nonzero temperature on the crystalline color
superconducting phase.


title:
Heavy particle electroweak loop effects in extra-dimensional models with
  bulk neutrinos

abstract:
  One way to detect the presence of new particles in theories beyond the
standard model is through their contribution to electroweak loop effects. We
comment on the importance of a consistent inclusion of their mixing angles to
ensure that the physical requirement of heavy particle decoupling is fulfilled.
We illustrate our points by a detailed discussion of the lepton flavor changing
effect mu-e-gamma, investigated recently by Kitano, in the Randall-Sundrum
model. Our remarks are equally applicable to models with large compactified
dimensions where bulk neutrinos are introduced to account for the observed
neutrino oscillations.


title:
Fractional Fokker-Planck Equation in Time Variable and Oscillation of
  Cumulant Moments

abstract:
  Fractional derivative in time variable is introduced into the Fokker-Planck
equation of a population growth model. It's solution, the KNO scaling function,
is transformed into the generating function for the multiplicity distribution.
Formulas of the factorial moment and the $H_j$ moment are derived from the
generating function, which reduces to that of the negative binomial
distribution (NBD), if the fractional derivative is replaced to the ordinary
one. In our approach, oscillation of $H_j$ moment appears contrary to the case
of the NBD. Calculated $H_j$ moments are compared with those given from the
data in $p\bar{p}$ collisions and in $e^+e^-$ collisions.


title:
High-energy interaction with the nucleus in the perturbative QCD with
  $N_c\to\infty$

abstract:
  The BFKL fan diagram equation for the scattering on the nucleus is solved
numerically with the eikonalized initial condition and for a realistic nuclear
density. The gluon density has a soliton-like form in the $\log q - y$ space.
Inclusive cross-sections for jet production in hA and AB collisions are
calculated.


title: New approaches to the determination of the total cross section

abstract:
  New methods have been developed for extracting the parameters of diffraction
scattering amplitude, $\sigma_{tot}$ and $\rho=Re F_N/Im F_N$, from
experimental data. The latter determines these parameters with less errors and
without the knowledge of the normalization coefficient. The impact of
additional information from the measurement of the spin-dependence cross
section on the determination of the basic characteristic of elastic scattering
amplitude is examined. The new form of the connection between some
characteristics of the analyzing power and magnitude of the $pp-$ total cross
section is presented.


title:
Particle rapidity density and collective phenomena in heavy ion
  collisions

abstract:
  We analyse recent results on charged particle pseudo-rapidity densities from
RHIC in the framework of the Dual String Model, in particular when including
string fusion. The model, in a simple way, agrees with all the existing data
and is consistent with the presence of the percolation transition to the
Quark-Gluon Plasma already at the CERN-SPS. It leads to strict saturation of
the particle (pseudo-)rapidity density, normalised to the number of participant
nucleons, as that number increases. A comparison with recent WA98 data is
presented.


title: Dynamical Symmetry Breaking in QED_3 from the Wilson RG Point of View

abstract:
  Dynamical symmetry breaking in three dimensional QED with $N$ flavors, which
has been mostly analyzed by solving the Schwinger-Dyson equations, is
investigated by means of the approximated Wilson, or non-perturbative,
renormalization group (RG). We study the RG flows of the gauge coupling and the
general four-fermi couplings allowed by the symmetry with concentrating our
interest on study of the phase structure. The RG equations have no gauge
parameter dependence in our approximation scheme. It is found that there exist
chirally broken and unbroken phases for $N > N_{\rm cr}$ ($3 < N_{\rm cr} < 4$)
and that the unbroken phase disappears for $N < N_{\rm cr}$. We also discuss
the spontaneous parity breaking in three dimensional QED with the four-fermi
interactions.


title: Non-standard Neutrino Properties

abstract:
  A discussion of several exotic models and how well they are able to describe
the data, with particular emphasis on atmospheric neutrinos.


title: Two Photon Physics at Future Linear Colliders

abstract:
  Prospects for QCD studies in two-photon interactions at a future linear e+e-
and gamma-gamma collider are discussed.


title: Total gamma-gamma and gamma*-gamma* Cross Sections Measured at LEP

abstract:
  Recent results on total cross-section measurements in gamma-gamma and
gamma*-gamma* collisions at LEP are reported. Phenomenological fits to the data
are presented.


title: Dirac and Majorana heavy neutrinos at LEP II

abstract:
  The possibility of detecting single heavy Dirac and Majorana neutrinos at LEP
II is investigated for heavy neutrino masses in the range $M_N=(\sqrt s/2,
\sqrt s)$. We study the process $e^+e^- \longrightarrow \nu_{\ell} \ell q_i
\bar q_j $ as a clear signature for heavy neutrinos. Numerical estimates for
cross sections and distributions for the signal and the background are
calculated and a Monte Carlo reconstruction of final state particles after
hadronization is presented.


title: Relativistic Many-Body Hamiltonian Approach to Mesons

abstract:
  We represent QCD at the hadronic scale by means of an effective Hamiltonian,
$H$, formulated in the Coulomb gauge. As in the Nambu-Jona-Lasinio model,
chiral symmetry is explicity broken, however our approach is renormalizable and
also includes confinement through a linear potential with slope specified by
lattice gauge theory. This interaction generates an infrared integrable
singularity and we detail the computationally intensive procedure necessary for
numerical solution. We focus upon applications for the $u, d, s$ and $c$ quark
flavors and compute the mass spectrum for the pseudoscalar, scalar and vector
mesons. We also perform a comparative study of alternative many-body techniques
for approximately diagonalizing $H$: BCS for the vacuum ground state; TDA and
RPA for the excited hadron states. The Dirac structure of the field theoretical
Hamiltonian naturally generates spin-dependent interactions, including tensor,
spin-orbit and hyperfine, and we clarify the degree of level splitting due to
both spin and chiral symmetry effects. Significantly, we find that roughly
two-thirds of the $\pi$-$\rho$ mass difference is due to chiral symmetry and
that only the RPA preserves chiral symmetry. We also document how hadronic mass
scales are generated by chiral symmetry breaking in the model vacuum. In
addition to the vacuum condensates, we compute meson decay constants and detail
the Nambu-Goldstone realization of chiral symmetry by numerically verifying the
Gell-Mann-Oaks-Renner relation. Finally, by including D waves in our charmonium
calculation we have resolved the anomalous overpopulation of $J/\Psi$ states
relative to observation.


title: Top Quark Yukawa Couplings and New Physics

abstract:
  We discuss associated production of a Higgs boson with a pair of $t {\bar t}$
quarks at a future high energy $e^+e^-$ collider. The process $e^+e^-\to t
{\bar t}h$ is particularly sensitive to the presence of new physics and we
consider the MSSM and models with extra dimensions at the $TeV$ scale as
examples.


title: Exclusive QCD

abstract:
  I give a brief introduction to the physics of generalized parton
distributions and distribution amplitudes. I then report on the status of the
calculation of radiative corrections for the exclusive processes where these
quantities occur.


title:
|Delta B|=1 Weak Effective Lagrangian in the Minimal Flavor Violation
  Supersymmetry

abstract:
  To evaluate the weak decays of b-hadrons, the $\Delta B=1$ weak effective
Lagrangian is the foundation. Any new physics beyond the standard model (SM)
would contribute to the effective Lagrangian through the loop integration at
the weak scale and evolution from the weak scale down to the hadronic scale. In
this work we present a systematic analysis on the effective Lagrangian which
mediates hadronic $|\Delta B|=1$ processes in the framework of the minimal
flavor violation supersymmetry as well as a numerical evaluation of the Wilson
coefficients in the effective theory.


title: Self-Organized Criticality in Gluon Systems and its Consequences

abstract:
  It is pointed out, that color-singlet gluon clusters can be formed in hadrons
as a consequence of self-organized criticality (SOC) in systems of interacting
soft gluons, and that the properties of such spatiotemporal complexities can be
probed experimentally by examing inelastic diffractive scattering. Theoretical
arguments and experimental evidence supporting the proposed picture are
presented. As a consequence of the space-time properties of the color-singlet
gluon clusters due to SOC in gluon systems, a simple analytical formula for the
differential cross section for inelastic diffractive hadron-hadron scattering
can be derived. The obtained results are in good agreement with the existing
data. Furthermore, it is shown that meson radii can be extracted from inelastic
diffractive scattering experiments. The obtained results for pion and kaon
charge radii are compared with those determined in meson form factor
measurements.


title: Production of MSSM Higgs Bosons in Photon-Photon Collisions

abstract:
  The heavy neutral Higgs bosons H, A in the minimal supersymmetric extension
of the Standard Model can be produced as single resonances at high-energy gamma
gamma colliders. We have studied the prospects of the search for these
particles in b\bar b and neutralino-pair final states. The Higgs bosons can be
found with masses up to 70-80% of the initial e^\pm e^- collider energy for
medium values of tan(beta), i.e. in areas of the supersymmetric parameter space
not accessible at other colliders.


title:
In-event background and signal reconstruction for two-photon
  invariant-mass analyses

abstract:
  A method is presented for the reconstruction of both the background and
signal in invariant-mass analyses for two-photon decays. The procedure does not
make use of event mixing techniques and as such is based exclusively on an
event-by-event analysis. Consequently, topological correlations of the event
(e.g. jet structures) are automatically taken into account. By means of the
decay process $\pi^{0} \to \gamma \gamma$ it will be demonstrated how the
procedure allows for determination of the $\pi^{0}$ yield from the observed
decay photons.


title: Vector Meson Production in the Golec-Biernat Wuesthoff Model

abstract:
  We apply the Golec-Biernat Wuesthoff model in the calculation of vector meson
photo- and electroproduction. Starting from very simple non-relativistic wave
functions we show that the model provides a good description of $J/\Psi$ cross
sections in wide $Q^2$ and $W$ ranges. For the light mesons one obtains the
approximately correct $W$ dependence and ratio of longitudinal to transverse
cross sections, although in this case the normalization, affected mainly by the
wave function employed, is not in good agreement with data.


title:
Full electroweak one-loop radiative corrections to squark decays in the
  MSSM

abstract:
  We present results on the full one-loop electroweak radiative corrections to
the squark decay partial widths into charginos and neutralinos. We show the
renormalization framework, and present numerical results for the third squark
family. The corrections can reach values of ~ 10%, which are comparable to the
radiative corrections from the strong sector of the model. Therefore they
should be taken into account for the precise extraction of the SUSY parameters
at future colliders.


title: Causality and CPT violation from an Abelian Chern-Simons-like term

abstract:
  We study a class of generalized Abelian gauge field theories where CPT
symmetry is violated by a Chern-Simons-like term which selects a preferred
direction in spacetime. Such Chern-Simons-like terms may either emerge as part
of the low-energy effective action of a more fundamental theory or be produced
by chiral anomalies over a nonsimply connected spacetime manifold.
Specifically, we investigate the issues of unitarity and causality. We find
that the behaviour of these gauge field theories depends on whether the
preferred direction is spacelike or timelike. For a purely spacelike preferred
direction, a well-behaved Feynman propagator exists and microcausality holds,
which indicates the possibility of a consistent quantization of the theory. For
timelike preferred directions, unitarity or causality is violated and a
consistent quantization does not seem to be possible.


title: Predictions for Neutrino Structure Functions

abstract:
  The first measurements of Delta- xF3 are higher than current theoretical
predictions. We investigate the sensitivity of these theoretical predictions
upon a variety of factors including: renormalization scheme and scale, quark
mass effects, higher twist, isospin violation, and PDF uncertainties.


title: Factorization in Color-Favored B Meson Decays to Charm

abstract:
  Improved $B$ meson decay data have permitted more incisive tests of
factorization predictions. A concurrent benefit is the ability to constrain the
Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$. Using a simultaneous fit
to differential distributions $d \Gamma(\ob \to D^{*+} l^- \bar \nu_l)/ dq^2$
measured by the CLEO and LEP Collaborations, the rates for the color-favored
decays $\ob \to D^{(*)+} (\pi^-,\rho^-,a_1^-)$, and the rate for $\ob \to D^+
l^- \bar \nu_l$, we find $|V_{cb}| = 0.0415 \pm 0.0022$. The slope of the
universal Isgur-Wise form factor is described by a parameter found to be $\rs =
1.52 \pm 0.11$. Taking the $D_s$ meson decay constant from the world average of
direct measurements, we predict satisfactorily the branching ratios for $\ob
\to D^{(*)+} D_s^{(*)-}$. Ratios of helicity amplitudes for color-favored
processes are also found to be in accord with predictions.


title:
Matter enhanced nu_mu->nu_e signals using various Fermilab main injector
  beam configurations

abstract:
  We calculate the sensitivity to nu_mu->nu_e appearance oscillations in
various Fermilab main injector neutrino beam configurations using simulations
of a MINOS-like detector and an OPERA-like detector. We make the assumption of
3 neutrino generations, and that only solar and atmospheric neutrino
oscillations signals are "real." We find that a 6 GeV neutrino beam pointed at
a fine-grained detector located at SLAC is optimal (for the central Super-K
atmospheric neutrino oscillation Delta-m-squared value). We show that
nu_mu->nu_e appearance signals and the sign of Delta-m_23-squared can be
obtained at the 3-sigma level for theta_13>3degrees.


title: Absolute Neutrino Mass Determination

abstract:
  We discuss four approaches to the determination of absolute neutrino mass.
These are the measurement of the zero-neutrino double beta decay rate, of the
tritium decay end-point spectrum, of the cosmic ray spectrum above the GZK
cutoff (in the Z-burst model), and the cosmological measurement of the power
spectrum governing the CMB and large scale structure. The first two approaches
are sensitive to the mass eigenstates coupling to the electron neutrino,
whereas the latter two are sensitive to the heavy component of the cosmic
neutrino background. All mass eigenstates are related by the $\Delta m^2$'s
inferred from neutrino oscillation data. Consequently, the potential for
absolute mass determination of each of the four approaches is correlated with
the other three, in ways that we point out.


title: CP Violation and the Scale of Supersymmetry Breaking

abstract:
  Supersymmetric models with a high supersymmetry breaking scale give, in
general, large contributions to epsilon_K and/or to various electric dipole
moments, even when contributions to CP conserving, flavor changing processes
are sufficiently suppressed. Some examples are models of dilaton dominance,
alignment, non-Abelian flavor symmetries, heavy first two generation sfermions,
anomaly mediation and gaugino mediation. There is then strong motivation for
`approximate CP', that is a situation where all CP violating phases are small.
In contrast, in supersymmetric models with a low breaking scale it is quite
plausible that the CKM matrix is the only source of flavor and CP violation.
Gauge mediation provides a concrete example. Approximate CP is then
unacceptable. Upcoming measurements of the CP asymmetry in B to \psi K_S might
exclude or support the idea of approximate CP and consequently probe the scale
of supersymmetry breaking.


title:
Neutrinos from Stellar Collapse: Comparison of signatures in water and
  heavy water detectors

abstract:
  Signatures of neutrino and antineutrino signals from stellar collapse in
heavy water detectors are contrasted with those in water detectors. The effects
of mixing, especially due to the highly dense matter in the supernova core, are
studied. The mixing parameters used are those sets allowed by current
understanding of available neutrino data: from solar, atmospheric and
laboratory neutrino experiments. Signals at a heavy water detector, especially
the dominant charged current reactions on deuteron, are very sensitive to some
of these sets of allowed mixing parameters. Theoretical uncertainties on
supernova neutrino spectra notwithstanding, a combination of supernova
measurements with water and heavy water detectors may be able to distinguish
many of these mixing possibilities and thus help in ruling out many of them.


title:
Loaded Dice in Monte Carlo: importance sampling in phase space
  integration and probability distributions for discrepancies

abstract:
  Discrepancies play an important role in the study of uniformity properties of
point sets. Their probability distributions are a help in the analysis of the
efficiency of the Quasi Monte Carlo method of numerical integration, which uses
point sets that are distributed more uniformly than sets of independently
uniformly distributed random points. In this thesis, generating functions of
probability distributions of quadratic discrepancies are calculated using
techniques borrowed from quantum field theory.
  The second part of this manuscript deals with the application of the Monte
Carlo method to phase space integration, and in particular with an explicit
example of importance sampling. It concerns the integration of differential
cross sections of multi-parton QCD-processes, which contain the so-called
kinematical antenna pole structures. The algorithm is presented and compared
with RAMBO, showing a substantial reduction in computing time.
  In behalf of completeness of the thesis, short introductions to probability
theory, Feynman diagrams and the Monte Carlo method of numerical integration
are included.


title:
Dependence of energy loss of jets on the initial thermodynamic state of
  deconfined matter at RHIC

abstract:
  The dependence of the radiative energy loss of fast partons on the initial
thermodynamic parameters is studied for deconfined matter to be expected at
RHIC. We demonstrate that the specific QCD radiation pattern with a quadratic
dependence of the energy loss on the propagated distance leads to a strong
increase of the energy loss with increasing initial entropy of deconfined
matter supposed its life-time is less than the average time to pass through the
medium. This is in contrast to a parameterization with constant energy loss per
unit length of propagation. For a sufficiently high initial temperature a
two-regime behavior of the energy loss as a function of the initial parton
momentum occurs. The angular structure of the energy loss of hard jets with
respect to the initial temperature is also discussed for RHIC conditions.


title: Sphalerons with Two Higgs Doublets

abstract:
  We report on work studying the properties of the sphaleron in models of the
electroweak interactions with two Higgs doublets in as model-independent a way
as possible: by exploring the physical parameter space described by the masses
and mixing angles of the Higgs particles. If one of the Higgs particles is
heavy, there can be several sphaleron solutions, distinguished by their
properties under parity and the behaviour of the Higgs field at the origin. In
general, these solutions are not spherically symmetric, although the departure
from spherical symmetry is small.


title: The CP-violating asymmetry in K_L -> pi+ pi- e+ e-

abstract:
  We update the theoretical analysis of the CP-violating asymmetry in the decay
K_L -> pi+ pi- e+ e-, relying on chiral perturbation theory and on the most
recent phenomenological information. With the experimentally determined
magnetic amplitude and branching ratio as input, the asymmetry can be
calculated with good accuracy. The theoretical interpretation of the sign of
the asymmetry is discussed.


title:
Large-Nc QCD meets Regge theory: the example of spin-one two-point
  functions

abstract:
  We discuss the phenomenological implications of assuming a Veneziano-type
spectrum for the vector and axial-vector two-point functions in QCD at large
Nc. We also compare the phenomenological results with those of Lowest-Meson
Dominance, and find that they agree.


title: Gluon shadowing in the low x region probed by the LHC

abstract:
  Starting from an unintegrated gluon distribution which satisfies a `unified'
equation which embodies both BFKL and DGLAP behaviour, we compute the shadowing
corrections to the integrated gluon in the small x domain that will be
accessible at the LHC. The corrections are calculated via the Korchegov
equation, which incorporates the leading ln(1/x) triple-Pomeron vertex, and are
approximately resummed using a simple Pade technique. We find that the
shadowing corrections to xg(x,Q^2) are rather small in the HERA domain, but
lead to a factor of 2 suppression in the region x \sim 10^-6, Q^2 \sim 4 GeV^2
accessible to experiments at the LHC.


title:
Measuring sigma(e+ e- --> hadrons) with Tagged Photons at Electron
  Positron Colliders

abstract:
  A Monte Carlo generator has been constructed to simulate the reaction e+ e-
--> gamma + 2 pions and gamma + 4 pions, where the photon is assumed to be
observed in the detector. Predictions are presented for cms energies of 1GeV,
3GeV and 10GeV, corresponding to the energies of DAPHNE, BEBC and of B-meson
factories. The event rates are sufficiently high to allow for a precise
measurement of R(Q^2) in the region of Q between approximately 1GeV and 2.5GeV.
Estimates for the kinematic breaking of isospin relations between different
channels as a consequence of the mass difference between charged and neutral
pions are given.


title: Mixing-Matrix Renormalization Revisited

abstract:
  We study the renormalization of normal mixing matrices, which includes
hermitian and unitary matrices as particular cases. We give a minimal,
multiplicative parametrization of counterterms, and compute the renormalized
Lagrangian to one-loop order in several models with N species of fermions, both
in on-shell and MS schemes. In on-shell scheme the mass-degenerate case is
considered separately.


title: Some aspects of baryogenesis and lepton number violation

abstract:
  The cosmological baryon asymmetry is closely related to neutrino properties
due to the non-perturbative sphaleron processes in the high-temperature
symmetric phase of the standard model. We review some aspects of this
connection with emphasis on cosmological bounds on neutrino masses,
leptogenesis and possible implications for dark matter.


title: The Quark-Gluon Plasma: Collective Dynamics and Hard Thermal Loops

abstract:
  We present a unified description of the high temperature phase of QCD, the
so-called quark-gluon plasma, in a regime where the effective gauge coupling
$g$ is sufficiently small to allow for weak coupling calculations. The main
focuss is the construction of the effective theory for the collective
excitations which develop at a typical scale $gT$, which is well separated from
the typical energy of single particle excitations which is the temperature $T$.
We show that the plasma particles provide a source for long wavelength
oscillations of average fields which carry the quantum numbers of the plasma
constituents, the quarks and the gluons. To leading order in $g$, the plasma
particles obey simple gauge-covariant kinetic equations, whose derivation from
the general Dyson-Schwinger equations is outlined. As a by-product, the ``hard
thermal loops'' emerge naturally in a physically transparent framework. We show
that the collective excitations can be described in terms of classical fields,
and develop for these a Hamiltonian formalism. The effect of collisions among
the hard particles is also studied, in particular in relation with the
effective theory for ultrasoft excitations, with momenta $\sim g^2T$.


title:
Pion-Pion Phase-Shifts and the Value of Quark-Antiquark Condensate in
  the Chiral Limit

abstract:
  We use low energy pion-pion phase-shifts in order to make distinction between
the alternatives for the value of the quark-antiquark condensate $B_0$ in the
chiral limit. We will consider the amplitude up to and including ${\cal
O}(p^4)$ contributions within the Standard and Generalized Chiral Perturbation
Theory frameworks. They are unitarized by means of Pad\'e approximants in order
to fit experimental phase-shifts in the resonance region. As the best fits
correspond to $\alpha = \beta = 1$, we conclude that pion-pion phase-shift
analysis favors the standard ChPT scenario, which assumes just one, large
leading order parameter $<\bar q q >_{_0}$.


title: Simulations of R-parity Violating SUSY Models

abstract:
  In recent years there has been a great deal of interest in R-parity violating
supersymmetric models. We explain the motivation for studying these models and
explore the various phenomenological consequences of R-parity violation. It has
become essential for the experimental study of any new model to have a Monte
Carlo event generator which includes the processes predicted by that model. We
review the techniques used in the construction of these simulations and show
how we have extended the HERWIG event generator to include R-parity violating
processes. We discuss how to treat the emission of QCD radiation in these
processes including colour coherence effects via the angular-ordered parton
shower.
  We then make use of this simulation to investigate the discovery potential
for resonant slepton production, via either supersymmetric gauge or R-parity
violating decay modes, in hadron-hadron collisions. Finally, we look at the
possibility that the KARMEN time anomaly can be explained by the existence of a
light neutralino which is produced and decays via R-parity violation.


title:
CP-Violating Phases in SUSY, Electric Dipole Moments, and Linear
  Colliders

abstract:
  We reexamine large CP-violating phases in the general Minimal Supersymmetric
Standard Model, as well as more restricted models. We perform a detailed scan
over parameter space to find solutions which satisfy the current experimental
limits on the electric dipole moments of the electron, neutron and $^{199}$Hg
atom, exploring the allowed configurations of phases and masses, and we attempt
to quantify the level of tuning of the parameters necessary to populate the
regions of cancellations. We then consider the measurement of CP-violating
phases at a future linear collider. We find that measurements of chargino and
neutralino masses and production cross-sections allow for a determination of
$\phi_1$(the phase of $M_1$) to a precision of $\pi/30$, while the EDM
constraints require that $\theta_\mu$ be too small to be measured. Using the
EDM constraints we find that the CP-even model parameters and the phase
$\phi_1$ can be determined at a Linear Collider with $400 \gev$ c.m. energy. As
long as some information on the size of $|\mu|$ is included in the observables,
a measurement of $\phi_1$ is guaranteed for $\phi_1 > \pi/10$. To unambiguously
identify CP violation, we construct CP-odd kinematical variables at a linear
collider. However, the CP asymmetries are rather small, typically about
$0.1-1.5%$, and it will be challenging to experimentally observe the predicted
asymmetries.


title:
ERG and Schwinger-Dyson Equations - Comparison in formulations and
  applications --

abstract:
  The advantageous points of ERG in applications to non-perturbative analyses
of quantum field theories are discussed in comparison with the Schwinger-Dyson
equations. First we consider the relation between these two formulations
specially by examining the large N field theories. In the second part we study
the phase structure of dynamical symmetry breaking in three dimensional QED as
a typical example of the practical applications.


title: Dynamical Spontaneous Symmetry Breaking in Quantum Chromodynamics

abstract:
  This study proposes that the longstanding problems of quantum chromodynamics
(QCD) as an SU(3)_C gauge theory, the confinement mechanism and \Theta vacuum,
can be resolved by dynamical spontaneous symmetry breaking (DSSB) through the
condensation of singlet gluons and quantum nucleardynamics (QND) as an SU(2)_N
\times U(1)_Z gauge theory is produced. The confinement mechanism is the result
of massive gluons and the Yukawa potential provides hadron formation. The
evidences for the breaking of discrete symmetries (C, P, T, CP) during DSSB
appear explicitly: baryons and mesons without their parity partners, the
conservation of vector current and the partial conservation of the axial vector
current, the baryon asymmetry \delta_B \simeq 10^{-10}, and the neutron
electric dipole moment \Theta < 10^{-9}.


title: Quantum Nucleardynamics as an SU(2)_N \times U(1)_Z Gauge Theory

abstract:
  It is shown that quantum nucleardynamics (QND) as an SU(2)_N \times U(1)_Z
gauge theory, which is generated from quantum chromodynamics (QCD) as an
SU(3)_C gauge theory through dynamical spontaneous symmetry breaking,
successfully describes nuclear phenomena at low energies. The proton and
neutron assigned as a strong isospin doublet are identified as a colorspin plus
weak isospin doublet. Massive gluon mediates strong interactions with the
effective coupling constant G_R/\sqrt{2}= g_n^2/8 M_G^2 \approx 10 GeV^{-2}
just like Fermi weak constant G_F/\sqrt{2} = g_w^2/8 M_W^2 \approx 10^{-5}
GeV^{-2} in the Glashow-Weinberg-Salam model where g_n and g_w are the coupling
constants and M_G and M_W are the gauge boson masses. Explicit evidences such
as lifetimes and cross sections of nuclear scattering and reaction, nuclear
matter and charge densities, nucleon-nucleon scattering, magnetic dipole
moment, gamma decay, etc. are shown in support of QND. The baryon number
conservation is the consequence of the U(1)_Z gauge theory and the proton
number conservation is the consequence of the U(1)_f gauge theory.


title:
Current quark mass effects on chiral phase transition of QCD in the
  improved ladder approximation

abstract:
  Current quark mass effects on the chiral phase transition of QCD is studied
in the improved ladder approximation. An infrared behavior of the gluon
propagator is modified in terms of an effective running coupling. The analysis
is based on a composite operator formalism and a variational approach. We use
the Schwinger-Dyson equation to give a ``normalization condition'' for the
Cornwall-Jackiw-Tomboulis effective potential and to isolate the ultraviolet
divergence which appears in an expression for the quark-antiquark condensate.
We study the current quark mass effects on the order parameter at zero
temperature and density. We then calculate the effective potential at finite
temperature and density and investigate the current quark mass effects on the
chiral phase transition. We find a smooth crossover for $T>0$, $\mu=0$ and a
first-order phase transition for $\mu>0$, T=0. Critical exponents are also
studied and our model gives the classical mean-field values. We also study the
temperature dependence of masses of scalar and pseudoscalar bosons. A critical
end point in the $T$-$\mu$ plane is found at $T \sim 100$ MeV, $\mu \sim 300$
MeV.


title: Phenomenology of the Chargino and Neutralino Systems

abstract:
  The chargino and neutralino pair production processes at $e^+e^-$ collisions
are explored to determine the underlying SUSY parameters. The sum rules for the
couplings are used to check the closure of two-chargino and four-neutralino
systems in the minimal supersymmetric extension of the standard model.


title: Radiative transitions in mesons in a non relativistic quark model

abstract:
  In the framework of the non relativistic quark model, an exhaustive study of
radiative transitions in mesons is performed. The emphasis is put on several
points. Some traditional approximations (long wave length limit, non
relativistic phase space, dipole approximation for E1 transitions, gaussian
wave functions) are analyzed in detail and their effects commented. A complete
treatment using three different types of realistic quark-antiquark potential is
made. The overall agreement with experimental data is quite good, but some
improvements are suggested.