title:
Measuring masses of semi-invisibly decaying particles pair produced at
  hadron colliders

abstract:
  We introduce a variable useful for measuring masses of particles pair
produced at hadron colliders, where each particle decays to one particle that
is directly observable and another particle whose existence can only be
inferred from missing transverse momenta. This variable is closely related to
the transverse mass variable commonly used for measuring the $W$ mass at hadron
colliders, and like the transverse mass our variable extracts masses in a
reasonably model independent way. Without considering either backgrounds or
measurement errors we consider how our variable would perform measuring the
mass of selectrons in a mSUGRA SUSY model at the LHC.


title:
Low Mass Higgs Boson Consistent with Precision Experiments: A
  Consequence of Large Top-Yukawa Coupling in Condensate Models

abstract:
  It is shown, using dispersion relations techniques for bound states, that the
presence of a large top-Yukawa coupling lowers the Higgs mass from the
condensate-model value of twice the top mass (~350 Gev) to 100-200 Gev
consistent with the Z(super 0) width precision measurements. The coupling is
found to be ~3.7 at the top-mass, much larger than the Standard Model value ~1.
It corresponds to a compositeness scale ~1.4 Tev, which is consistent with
top-color models, and implies quite different scales for fermion mass
generation and electroweak symmetry breaking. A second scalar state around 1
Tev also emerges as a solution in combination with the low mass Higgs.


title: Can the Higgs Boson Bootstrap itself?

abstract:
  It is pointed out that Higgs bootstrap is inherent in the top-condensate
models of Nambu and Bardeen et al in that the ladder sum of Higgs pole diagrams
in one channel reproduces a Higgs pole in the crossed-channel. This result is
exact whenever color flows simultaneously in both channel directions e.g. for
N(sub c)=1. Bootstrap solutions for the Higgs boson mass are obtained that are
compatible with the condensate models such as the top-color models which imply
large top-Yukawa couplings at the top mass.


title: More on triangular mass matrices for fermions

abstract:
  A direct proof is given here which shows that instead of 6 complex numbers,
the triangular mass matrix for each sector could just be expressed in terms of
5 by performing a specific weak basis transformation, leading therefore to a
new textures for triangular mass matrices.
  Furthermore, starting with the set of 20 real parameters for both sectors, it
can shown that 6 redundant parameters can be removed by using the rephasing
freedom.


title: X Rays from Old Neutron Stars Heated by Axion Stars

abstract:
  We show that axionic boson stars collide with isolated old neutron stars with
strong magnetic field ($>10^8$ Gauss) and causes the neutron stars to radiate X
ray by heating them. Surface temperatures of such neutron stars becomes$10^5 K
\sim 10^6 K$. We suggest that these are possible candidates for X ray sources
observed in ROSAT Survey. We discuss a possible way of identifying such neutron
stars. We also point out that the collision generates a burst of monochromatic
radiations with frequency given by axion mass.


title: Are electroweak corrections at 1 TeV under control at the 1 % level?

abstract:
  Future lepton colliders will provide a powerful tool for making precision
experiments at energies that will range typically between
  500 GeV and 2 TeV. At such high energies, one loop electroweak corrections
are bigger than one could naively expect a priori. Thus, the calculation of
higher order electroweak effects (and possibly their resummation) might be
needed.


title:
Some Topics on Double Heavy Mesons: Heavy Quarkonia and $B_c$ Meson
  (Advances and outlooks)

abstract:
  The most important advances achieved recently on the double heavy flavored
mesons are reviewed. Some problems and outlooks on them are also outlined.


title: Left-right symmetry and heavy particle quantum effects

abstract:
  We have renormalized a classical left-right model with a bidoublet, and left
and right triplets in the Higgs sector. We focus on oblique corrections and
show the interplay between the top quark, heavy neutrinos and Higgses
contribution to the muon $\Delta r$ parameter. In the SM, custodial symmetry
prevents large oblique corrections to appear. Although in LR models there is no
such symmetry to make vanish the quadratically diverging terms, we have shown,
that heavy Higgses contributions to $\Delta r$ are under control. Also the top
contribution to $\Delta r$, quite different from that in the SM, is discussed.
However, heavy neutrinos seem to give the most important contributions. From
oblique corrections, they can be as large as the SM top one. Moreover, vertex
and box diagrams give additional non-decoupling effects and only concrete
numerical estimates are able to answer whether the model is still
self-consistent.


title: Phases and Amplitudes in Inclusive $\Psi$ and $\Psi'$ Decays

abstract:
  In inclusive decays of the $\Psi$ (3097), electromagnetic and gluonic
annihilation amplitudes add incoherently, namely they are 90$^\circ$ out of
phase. We argue that this incoherence must persist in each exclusive decay
channel. For inclusive $\Psi'$ (3686) decays, we suggest the absence of a
significant direct annihilation amplitude into three gluons and propose a new
amplitude via QCD anomalies and the $h_c$ (3526) off shell. Phenomenological
implications for exclusive decay channels are pointed out.


title: A Tachyonic Gluon Mass: Between Infrared and Ultraviolet

abstract:
  The gluon spin coupling to a Gaussian correlated background gauge field
induces an effective tachyonic gluon mass. It is momentum dependent and
vanishes in the UV only like 1/p^2. In the IR, we obtain stabilization through
a positive m^2_{conf}(p^2) related to confinement. Recently a purely
phenomenological tachyonic gluon mass was used to explain the linear rise in
the q\bar q static potential at small distances and also some long standing
discrepancies found in QCD sum rules. We show that the stochastic vacuum model
of QCD predicts a gluon mass with the desired properties.


title: Meson Structure in a Relativistic Many-Body Approach

abstract:
  Results from an extensive relativistic many-body analysis utilizing a
realistic effective QCD Hamiltonian are presented for the meson spectrum. A
comparative numerical study of the BCS, TDA and RPA treatments provides new,
significant insight into the condensate structure of the vacuum, the chiral
symmetry governance of the pion and the meson spin, orbital and flavor mass
splitting contributions. In contrast to a previous glueball application,
substantial quantitative differences are computed between TDA and RPA for the
light quark sector with the pion emerging as a Goldstone boson only in the RPA.


title: A study of Schwinger-Dyson Equations for Yukawa and Wess-Zumino Models

abstract:
  We study Schwinger-Dyson equation for fermions in Yukawa and Wess-Zumino
models, in terms of dynamical mass generation and the wavefunction
renormalization function. In the Yukawa model with $\gamma_5$-type interaction
between scalars and fermions, we find a critical coupling in the quenched
approximation above which fermions acquire dynamical mass. This is shown to be
true beyond the bare 3-point vertex approximation. In the Wess-Zumino model,
there is a neat cancellation of terms leading to no dynamical mass for
fermions. We comment on the conditions under which these results are general
beyond the rainbow approximation and also on the ones under which supersymmetry
is preserved and the scalars as well do not acquire mass. The results are in
accordance with the non-renormalization theorem at least to order $\alpha$ in
perturbation theory. In both the models, we also evaluate the wavefunction
renormalization function, analytically in the neighbourhood of the critical
coupling and numerically, away from it.


title:
Effective Restoration of the U_A(1) symmetry in the SU(3) linear sigma
  model

abstract:
  The effective restoration of the chiral U(A)(1) symmetry in strong
interactions is studied using the linear chiral SU(3)xSU(3) model at finite
temperatures. We find that the disappearance of the chiral anomaly causes a
considerable change in the meson mass spectrum. We propose several signals for
detecting this chiral phase in ultrarelativistic heavy-ion collisions: The
eta/pi0 ratio is enhanced by an order of magnitude, the a0 is suppressed in the
K+K- mass spectrum, and the scalar kappa meson appears as a peak just below the
K*(892) in the invariant piK mass spectrum.


title:
Neutrino Masses, Mixing Angles and the Unification of Couplings in the
  MSSM

abstract:
  In the light of the gathering evidence for $\nu_{\mu}-\nu_{\tau}$ neutrino
oscillations, coming in particular from the Super-Kamiokande data on
atmospheric neutrinos, we re-analyze the unification of gauge and Yukawa
couplings within the minimal supersymmetric extension of the Standard Model
(MSSM). Guided by a range of different grand-unified models, we stress the
relevance of large mixing in the lepton sector for the question of bottom-tau
Yukawa coupling unification. We also discuss the dependence of the favoured
value of $\tan\beta$ on the characteristics of the high-energy quark and lepton
mass matrices. In particular, we find that, in the presence of large lepton
mixing, Yukawa unification can be achieved for intermediate values of
$\tan\beta$ that were previously disfavoured. The renormalization-group
sensitivity to the structures of different mass matrices may enable Yukawa
unification to serve as a useful probe of GUT models.


title: Dynamical solution to the $\mu$ problem at TeV scale

abstract:
  We introduce a new confining force (\mu-color) at TeV scale to dynamically
generate a supersymmetry preserving mass scale which would replace the \mu
parameter in the minimal supersymmetric standard model (MSSM). We discuss the
Higgs phenomenology and also the pattern of soft supersymmetry breaking
parameters allowing the correct electroweak symmetry breaking within the
\mu-color model, which have quite distinctive features from the MSSM and also
from other generalizations of the MSSM.


title:
Running Coupling Constants of Fermions with Masses in Quantum Electro
  Dynamics and Quantum Chromo Dynamics

abstract:
  Based on a simple but effective regularization-renormalization method (RRM),
the running coupling constants (RCC) of fermions with masses in quantum
electrodynamics (QED) and quantum chromodynamics (QCD) are calculated by
renormalization group equation (RGE). Starting at Q=0 ($Q$ being the momentum
transfer), the RCC in QED increases with the increase of $Q$ whereas the RCCs
for different flavors of quarks with masses in QCD are different and they
increase with the decrease of $Q$ to reach a maximum at low $Q$ for each flavor
of quark and then decreases to zero at $Q\longrightarrow 0$. The physical
explanation is given.


title: Initial condition for new inflation in supergravity

abstract:
  We study the initial value problem of new inflation models in the scheme of
supergravity. We find that an inflaton generally acquires a mass of the order
of the Hubble parameter via gravitationally suppressed interactions with
particles in the thermal bath of the universe. This additional mass term
stabilizes dynamically the inflaton at the local maximum of the potential,
which offers the initial condition of new inflation.


title: Leptogenesis in Inflaton Decay

abstract:
  We study a leptogenesis via decays of heavy Majorana neutrinos produced
non-thermally in inflaton decays. We find that this scenario is fully
consistent with existing supersymmetric inflation models such as for
topological or for hybrid inflation and the Froggatt-Nielsen mechanism
generating hierarchies in quark and lepton mass matrices. The reheating
temperature $T_R$ of inflation may be taken as low as $T_R \simeq 10^8$ GeV to
avoid the cosmological gravitino problem.


title: Chiral symmetry in linear Sigma model in magnetic environment

abstract:
  We study the chiral symmetry structure in a linear sigma model with fermions
in the presence of an external, uniform magnetic field in the 'effective
potential' approach at the one loop level. We also study the chiral phase
transition as a function of density in the core of magnetized neutron stars.


title: Large Neutrino Mixing with Universal Strength of Yukawa Couplings

abstract:
  We analyse, within the framework of universal strength for Yukawa couplings
(USY), various structures for the Dirac and Majorana neutrino mass matrices
giving rise, through the see-saw mechanism, to a degenerate mass spectrum. A
specific USY ansatz is presented for the charged lepton and neutrino effective
mass matrix, leading to quasi-degenerate neutrinos and a leptonic mixing matrix
which provides a large angle solution for both the atmospheric and solar
neutrino problems.


title: Monojet rates in ultrarelativistic heavy ion collisions

abstract:
  Basing on model concepts we research the monojet-to-dijet ratio as a function
of the jet energy detection threshold in ultrarelativistic collisions of
nuclei. We provide an comparative analysis of the contribution to monojet yield
from gluon radiation before initial hard parton-parton scattering and from
non-symmetric dijet energy losses in quark-gluon plasma, which expected to be
created in ultrarelativistic heavy ion collisions.


title: Applicability of perturbative QCD to $\Lambda_b \to \Lambda_c$ decays

abstract:
  We develop perturbative QCD factorization theorem for the semileptonic heavy
baryon decay $\Lambda_b \to \Lambda_c l\bar{\nu}$, whose form factors are
expressed as the convolutions of hard $b$ quark decay amplitudes with universal
$\Lambda_b$ and $\Lambda_c$ baryon wave functions. Large logarithmic
corrections are organized to all orders by the Sudakov resummation, which
renders perturbative expansions more reliable. It is observed that perturbative
QCD is applicable to $\Lambda_b \to \Lambda_c$ decays for velocity transfer
greater than 1.2. Under requirement of heavy quark symmetry, we predict the
branching ratio $B(\Lambda_b \to \Lambda_c l{\bar\nu})\sim 2%$, and determine
the $\Lambda_b$ and $\Lambda_c$ baryon wave functions.


title:
Radially excited scalar, pseudoscalar, and vector meson nonets in a
  chiral quark model

abstract:
  A chiral Lagrangian containing, besides the usual meson fields, their first
radial excitations is constructed. The Lagrangian is derived by bosonization of
a Nambu--Jona-Lasinio (NJL) type quark model with separable nonlocal
interactions. The nonlocality is described by form factors corresponding to
3-dimensional excited state wave functions. The spontaneous breaking of chiral
symmetry is governed by the standard NJL gap equations. A simple SU(2)xSU(2)
version of the model is used to demonstrate all low-energy theorems to hold
valid in the chiral limit. A more realistic U(3)xU(3) model with 't Hooft
interaction is constructed to describe the mass spectrum of excited scalar,
pseudoscalar, and vector mesons. On the basis of global chiral symmetry, we use
the same form factors for the scalar and pseudoscalar mesons. Having fixed the
form factor parameters by masses of pseudoscalar mesons, we predict the mass
spectrum of scalar mesons. This allows us to interpret experimentally observed
scalar, pseudoscalar, and vector meson states as members of quark-antiquark
nonets. It is shown that the a_0(1450), K^*_0(1430), f_0(1370), f_J(1710)
scalar meson states are the first radial excitations of the ground states:
a_0(980), K^*_0(960), f_0(400-1200), f_0(980). The weak decay constants F_\pi,
F_{\pi'}, F_K, F_{K'} and the main strong decay widths of the scalar,
pseudoscalar, and vector meson nonets are calculated.


title:
A VMD Based, Nonet and SU(3) Symmetry Broken Model For Radiative Decays
  of Light Mesons

abstract:
  We present a VMD based model aiming to describe all radiative decays of light
mesons. We show that the SU(3) breaking mechanism proposed by Bando, Kugo and
Yamawaki (BKY), supplemented by nonet symmetry breaking in the pseudoscalar
sector are sufficient to provide a nice description of all data, except the
charged K* radiative width. It is also shown that nonet symmetry breaking has
effects which cannot be disantangled from those produced by coupling of glue to
the eta' meson. Coupling of glue to $\eta$ is not found to be required by the
data.
  Asssuming the charged K* radiative width is indeed at its presently accepted
value necessitates to supplement the BKY breaking in a way which finally
preserves an equivalence statement between the VMD approach to radiative decays
and the Wess-Zumino-Witten Lagrangian.


title: Transverse spectra of induced radiation

abstract:
  Transverse spectra of induced radiation are discussed within the light-cone
path integral approach to the LPM effect. The results are applicable in both
QED and QCD.


title:
Supersymmetric CP violation $\epsilon'/\epsilon$ due to asymmetric
  A-matrix

abstract:
  We study contributions of supersymmetric CP phases to the CP violation
$\epsilon'/\epsilon$ in models with asymmetric $A$-matrices. We consider
asymmetric $A$-matrices, which are obtained from string-inspired supergravity.
We show that a certain type of asymmetry of $A$-matrices enhances
supersymmetric contributions to the CP violation $\epsilon'/\epsilon$ and the
supersymmetric contribution to $\epsilon'/\epsilon$ can be of order of the KTeV
result, $\epsilon'/\epsilon \sim 10^{-3}$.


title: Can the Zee ansatz for neutrino masses be correct?

abstract:
  Working in the framework of three chiral neutrinos with Majorana masses, we
investigate a scenario first realized in an explicit model by Zee: that the
neutrino mass matrix is strictly off-diagonal in the flavor basis, with all its
diagonal entries precisely zero. This CP-conserving ansatz leads to two
relations among the three mixing angles $(\theta_1, \theta_2, \theta_3)$ and
two squared mass differences. We impose the constraint $|m_3^2 - m_2^2| \gg
|m^2_2 - m_1^2|$ to conform with experiment, which requires the $\theta_i$ to
lie nearby one of four 1-parameter domains in $\theta$-space. We exhibit the
implications for solar and atmospheric neutrino oscillations in each of these
cases. A unique version of the Zee {\it ansatz} survives confrontation with
experimental data, one which necessarily involves maximal just-so vacuum
oscillations of solar neutrinos.


title:
Lattice QCD calculation of $\bar{B}\to Dl\bar{\nu}$ decay form factors
  at zero recoil

abstract:
  A lattice QCD calculation of the $\bar{B}\to Dl\bar{\nu}$ decay form factors
is presented. We obtain the value of the form factor $h_+(w)$ at the
zero-recoil limit $w=1$ with high precision by considering a ratio of
correlation functions in which the bulk of the uncertainties cancels. The other
form factor $h_-(w)$ is calculated, for small recoil momenta, from a similar
ratio. In both cases, the heavy quark mass dependence is observed through
direct calculations with several combinations of initial and final heavy quark
masses. Our results are $h_+(1) = 1.007(6)(2)(3)$ and
$h_-(1)=-0.107(28)(04)(^{10}_{30})$. For both the first error is statistical,
the second stems from the uncertainty in adjusting the heavy quark masses, and
the last from omitted radiative corrections. Combining these results, we obtain
a precise determination of the physical combination $F_{B\to
D}(1)=1.058(^{20}_{17})$, where the mentioned systematic errors are added in
quadrature. The dependence on lattice spacing and the effect of quenching are
not yet included, but with our method they should be a fraction of $F_{B\to
D}-1$.


title: The monopoles in the structure of the electron

abstract:
  The classical electron is presented as made up of an electric charge and two
Dirac monopoles of opposite charge performing a magnetic dipole. It is
discussed that a valid variational principle for this system can be defined.
The Dirac quantization condition for charges can be derived in Quantum
Electrodynamics as monopoles are properly defined in the structure. Further
comments on the subject are addressed since the proper care of Dirac strings is
still an open issue.


title: Neutrino masses: From fantasy to facts

abstract:
  Theory suggests the existence of neutrino masses, but little more. Facts are
coming close to reveal our fantasy: solar and atmospheric neutrino data
strongly indicate the need for neutrino conversions, while LSND provides an
intriguing hint. The simplest ways to reconcile these data in terms of neutrino
oscillations invoke a light sterile neutrino in addition to the three active
ones. Out of the four neutrinos, two are maximally-mixed and lie at the LSND
scale, while the others are at the solar mass scale. These schemes can be
distinguished at neutral-current-sensitive solar & atmospheric neutrino
experiments. I discuss the simplest theoretical scenarios, where the lightness
of the sterile neutrino, the nearly maximal atmospheric neutrino mixing, and
the generation of $\Delta {m^2}_\odot$ & $\Delta {m^2}_{atm}$ all follow
naturally from the assumed lepton-number symmetry and its breaking. Although
the most likely interpretation of the present data is in terms of
neutrino-mass-induced oscillations, one still has room for alternative
explanations, such as flavour changing neutrino interactions, with no need for
neutrino mass or mixing. Such flavour violating transitions arise in theories
with strictly massless neutrinos, and may lead to other sizeable flavour
non-conservation effects, such as $\mu \to e + \gamma$, $\mu-e$ conversion in
nuclei, unaccompanied by neutrino-less double beta decay.


title: Getting Ready for CP Violation in B decays

abstract:
  We review some recent results on b decays relevant to future CP violation
studies. In particular, some new data on rare hadronic B decays will be
presented, as well as inclusive searches for evidence for gluonic penguins and
first hints of final state interaction phases in B decays to D* rho. The
results discussed are based on data collected by the CLEO experiment including
up to 5.8 x 10 ^6 B Bbar pairs.


title:
Advanced method of solving recurrence relations for multi-loop Feynman
  integrals

abstract:
  The systematic approach to solving the recurrence relations for multi-loop
integrals is described. In particular, the criteria of their reducibility is
suggested.


title: Nature of neutrinos in the light of present and future experiments

abstract:
  Two general models with hierarchical and almost degenerate neutrino masses,
which are able to explain the solar and atmospheric anomalies are investigated.
We show how neutrinoless double beta decay experiments discern Dirac and
Majorana natures of neutrinos. The strongest result is, that almost degenerate
neutrinos with masses above 0.22 eV combined with the SMA MSW must be Dirac
particles. In the general case, the same bound is true for specific parity
assignments. In the near future (GENIUS experiment), one of the hierarchical
schemes, and the VO mechanism for almost degenerate neutrinos and specific
mixing matrix elements and parity assignments will be tested.


title: Measuring the QCD Gell Mann-Low $\Psi$-function

abstract:
  We present a general method for extracting the Gell Mann-Low logarithmic
derivative of an effective charge of an observable directly from data as a mean
for empirically verifying the universal terms of the QCD $\beta$-function. Our
method avoids the biases implicit in fitting to QCD-motivated forms as well as
the interpolation errors introduced by constructing derivatives from discrete
data. We also derive relations between moments of effective charges as new
tests of perturbative QCD.


title: Radiatively Generated Neutrino Masses in SU(3)_L x U(1)_N Gauge Models

abstract:
  In SU(3)_L x U(1)_N gauge models for electroweak interactions, we discuss how
to implement a radiative mechanism of generating Majorana neutrino masses by
considering the property that the Higgs scalar, which has a coupling to a
charged lepton (\ell)-neutrino (\nu) pair, is naturally included. The mechanism
is shown to work in models with a heavy charged lepton, \omega^+, in a lepton
triplet (\nu, \ell, \omega^+) and with a heavy neutral lepton, N, in (\nu,
\ell, N). A minimal model with \ell and \ell^c in (\nu, \ell, \ell^c) together
with a sextet Higgs scalar suffers from a fine-tuning problem to suppress
tree-level neutrino masses.


title: W boson production at upgraded HERA

abstract:
  Event characteristics of $W$ boson production at HERA collider are untrivial
and sensitive to the production mechanisms. We analyse the distributions of the
four particle final state defined by the complete set of $W$ producing
perturbative leading order diagrams in the Standard Model and its extension
with the anomalous effective lagrangian in the gauge sector.


title:
Constraints on the R-parity Violating Couplings from $B^\pm \to l^\pm
  \nu$ Decays

abstract:
  We derive the upper bounds on certain products of R-parity- and
lepton-flavor-violating couplings from $B^\pm \to l^\pm \nu$ decays. These
modes of B-meson decays can constrain the product combinations of the couplings
with one or more heavy generation indices which are comparable with or stronger
than the present bounds. And we investigate the possible effects of R-parity
violating interactions on $B_c \to l \nu$ decays. These decay modes can be
largely affected by R-parity violation.


title: Electroweak moments of baryons and hidden strangeness of the nucleon

abstract:
  The phenomenological sum-rule-based approach is used to discuss the quark
composition dependence of some static electroweak characteristics of
baryons.The role of nonvalence degrees of freedom (the sea partons and/or
peripheral meson currents) is shown to be important to select and make use of
the relevant symmetry parametrization of baryon observables.The implications of
the baryon magnetic moment analysis for estimation of the $\Delta$q values of
the spin-dependent DIS on nucleons, the contribution of hidden strangeness to
the nucleon magnetic moment and to the quark-line-rule violating $\phi \pi$ -
production in antinucleon-nucleon annihilation reaction are presented.


title: J/Psi theory review, or from J to Psi

abstract:
  1) Hard exclusive processes in QCD: main characteristic properties; 2)
Experimental and theoretical status of the J/Psi and Psi^\prime decays.


title: Gravitino production during preheating

abstract:
  We study the production of gravitinos during the preheating era after
inflation by means of the non-perturbative Bogolyubov technique. Considering
only the helicity $\pm 3/2$ states, the problem is reduced to the simpler Dirac
fermions case. We calculate the production in a particular supergravity model
in an expanding universe and obtain the spectrum and number density. Finally we
compare the results with the nucleosynthesis bounds and extract some
consequences.


title:
Counterterms for Linear Divergences in Real-Time Classical Gauge
  Theories at High Temperature

abstract:
  Real-time classical SU($N$) gauge theories at non-zero temperature contain
linear divergences. We introduce counterterms for these divergences in the
equations of motion in the continuum and on the lattice. These counterterms can
be given in terms of auxiliary fields that satisfy local equations of motion.
We present a lattice model with 6+1D auxiliary fields that for IR-sensitive
quantities yields cut-off independent results to leading order in the coupling.
Also an approximation with 5+1D auxiliary fields is discussed.


title: Density correlators in a self-similar cascade

abstract:
  Multivariate density moments (correlators) of arbitrary order are obtained
for the multiplicative self-similar cascade. This result is based on the
calculation by Greiner, Eggers and Lipa (reference [1]) where the correlators
of the logarithms of the particle densities have been obtained. The density
correlators, more suitable for comparison with multiparticle data, appear to
have even simpler form than those obtained in [1].


title:
Gluon condensate, quark propagation, and dilepton production in the
  quark-gluon plasma

abstract:
  A calculation of the thermal quark propagator is presented taking the gluon
condensate above the critical temperature into account. The quark dispersion
relation and the dilepton production following from this propagator are
derived.


title:
Nonthermal Axino as Cool Dark Matter in Supersymmetric Standard Model
  without R-parity

abstract:
  We point out that the axino predicted as the supersymmetric partner of the
axion is a good candidate for the recently proposed sterile neutrino cool dark
matter. The axino mass falls into the right range in the context of gauge
mediated supersymmetry breaking. A sizable mixing of the axino with active
neutrinos arises when R-parity violation is allowed and the resulting neutrino
masses and mixing accommodate the atmospheric and solar neutrino oscillations
simultaneously.


title: The rigorous analyticity-unitarity program and its successes

abstract:
  We show how the combination of analyticity properties derived from local
field theory and the unitarity condition (in particular positivity) leads to
non-trivial physical results, including the proof of the "Froissart bound" from
first principles and the existence of absolute bounds on the pion-pion
scattering amplitude.


title:
Neutralino Relic Density with a Cosmological Constant confronts
  Electroweak Precision Measurements

abstract:
  We discuss the relic density of the lightest of the supersymmetric particles
({\small LSP}) in view of new cosmological data, which favour the concept of an
accelerating Universe with a non-vanishing cosmological constant. The new bound
on the Cold Dark Matter density, $\Omega_{\mathrm{CDM}} h_0^2 \lesssim 0.22$,
puts stringent constraints on supersymmetry preferring low supersymmetry
breaking scales, in sharp contrast to electroweak precision measurements
favouring large supersymmetry breaking scales. Supersymmetric predictions are
in agreement with cosmological data and electroweak precision data in the
window of the parameter space: $m_0<200\GeV$, $300\GeV<M_{1/2}<400\GeV$,
putting bounds on sparticle masses, which may be evaded if $m_{LSP}
<m_{{\tilde{\tau}}_R} \lesssim 1.2 m_{LSP}$.


title:
Can the trilinear Higgs self-coupling be measured at future linear
  colliders?

abstract:
  We assess the possibility of measuring the trilinear self-coupling of the
Standard Model Higgs boson at future electron-positron linear colliders with
centre-of-mass energies between 500 and 1500 GeV. We consider rather light
Higgs scalars, with mass below the W+W- threshold, produced in the double
Higgs-strahlung channel e+e- -> HHZ and decaying via the dominant mode H ->
bbbar. Assuming ideal vertex tagging of the heavy-quark jets and mass
reconstruction of the Z boson produced in association with the Higgs pair, we
compare the yield of the above process to those of all irreducible electroweak
and strong backgrounds proceeding through a bbbar bbbar Z intermediate state.
Total cross sections and differential spectra of phenomenological relevance to
the selection and analysis of the signal are given and discussed.


title:
Coupled-Channel Final-State Interactions through Reggeon Exchange for
  D(B) --> \pi \pi, K \bar{K}

abstract:
  Coupled-channel final-state-interaction effects for D and B weak decays into
\pi \pi and K \bar{K} are discussed in a Regge framework. It is found that the
inclusion of coupled-channel effects significantly affects the results obtained
previously in a quasi-elastic approximation. It is also shown that in the
isospin I=0 channel the inelastic final-state transitions (\pi \pi)_{I=0} -->
(K \bar{K})_{I=0} dramatically influence the phase of the B^0 --> (K
\bar{K})_{I=0} amplitude.


title:
Low energy consequences from supersymmetric models with left-right
  symmetry

abstract:
  We consider several low energy consequences arising from a class of
supersymmetric models based on the gauge groups $SU(2)_L\times SU(2)_R \times
U(1)_{B-L}$ and $SU(4)_C\times SU(2)_L \times SU(2)_R$ in which the gauge
hierarchy and $\mu$ problems have been resolved. There are important
constraints on the MSSM parameters $\tan \beta (\simeq m_t/m_b)$, $B$ and
$\mu$, and we discuss how they are reconciled with radiative electroweak
breaking. We also consider the ensuing sparticle and Higgs spectroscopy, as
well as the decays $b\to s \gamma$ and $\mu \to e \gamma$. The latter process
may be amenable to experimental tests through an order of magnitude increase in
sensitivity.


title: RHIC predictions from the UrQMD model

abstract:
  The Ultra-relativistic Quantum-Molecular-Dynamics model (UrQMD) is used to
study central Pb+Pb reactions at RHIC ($\sqrt{s}=200$ AGeV). The computed
collision spectrum reveals that the major part (approx. 80%) of the dynamics is
governed by interactions below $\sqrt{s}=100$ GeV. Rapidity spectra of
net-baryons (Protons, Hyperons) and produced particles (Pions, Kaons) are
predicted. The transverse expansion is studied.


title:
Direct determination of the gluon density in the proton from jet cross
  sections in deep-inelastic scattering

abstract:
  A QCD analysis of jet production in deep-inelastic scattering is presented.
The studies are based on recent measurements of jet cross sections in the H1
experiment at HERA which are directly sensitive to the gluon density in the
proton. The inclusion of H1 data on the inclusive deep-inelastic scattering
cross section enables us to perform a consistent, simultaneous determination of
the quark and gluon densities in the proton. The gluon density has been
determined at fairly large values of $0.01 < x < 0.1$ at a scale of the order
of the transverse jet energies $\mu^2_f = 200\GeV^2$. The result is consistent
with indirect determinations from HERA structure function data and extends
their range of sensitivity to larger $x$-values.


title:
Gauge Boson - Gauge Boson Scattering in Theories with Large Extra
  Dimensions

abstract:
  We consider the scattering amplitudes of the form V_1 V_2 -> V_3 V_4, where
V_i=\gamma, Z, W or g(=gluon) are the Standard Model gauge bosons, due to
graviton exchange in Kaluza-Klein theories with large extra dimensions. This
leads to a number of experimentally viable signatures at high energy leptonic
and hadronic colliders. We discuss the observability or future limits on the
scale of the gravitational interactions (m_D), that may be obtained at an e+e-
Next Linear Collider (NLC) and at the LHC, by studying some of these type of
gauge boson scattering processes. We find that the attainable limits through
these type of processes are: m_D > 3 TeV at the NLC and m_D > 6 TeV at the LHC.


title:
Pionic Measures of Parity and CP Violation in High Energy Nuclear
  Collisions

abstract:
  The collisions of large nuclei at high energies could produce metastable
vacua which are odd under parity, P, charge conjugation, C, and/or CP. Using
only the three-momenta of charged pions (or kaons), we show how to construct
global observables which are odd under P, C, and CP, and which can be measured
on an event by event basis. Model dependent estimates of the P-odd observables
are on the order of 10^(-3).


title: Low mass lepton pair production in hadron collisions

abstract:
  The hadroproduction of lepton pairs with mass $Q$ and transverse momentum
$Q_T$ can be described in perturbative QCD by the same partonic subprocesses as
prompt photon production. We demonstrate that, like prompt photon production,
lepton pair production is dominated by quark-gluon scattering in the region
$Q_T>Q/2$. This leads to sensitivity to the gluon density in kinematical
regimes that are accessible both at collider and fixed target experiments while
eliminating the theoretical and experimental uncertainties present in prompt
photon production.


title: The Delta I=1/2 Rule in Kaon Decays: A New Look

abstract:
  The $K\to\pi\pi$ decay amplitudes are studied within the framework of
generalized factorization in which the effective Wilson coefficients are
gauge-invariant, renormalization-scale and -scheme independent while
factorization is applied to the tree-level hadronic matrix elements.
Nonfactorized contributions to the hadronic matrix elements of (V-A)(V-A)
four-quark operators, which are needed to account for the suppression of the
$\Delta I=3/2 K\to\pi\pi$ amplitude $A_2$ and the enhancement of the $\Delta
I=1/2 A_0$ amplitude, are phenomenologically extracted from the measured
$K^+\to\pi^+\pi^0$ decay and found to be large. The $A_0/A_2$ ratio is
predicted to lie in the range 15-17 for $m_s(1 GeV)=(127-150)$ MeV. Vertex and
penguin-type radiative corrections to the matrix elements of four-quark
operators and nonfactorized effects due to soft-gluon exchange account for the
bulk of the $\Delta I=1/2$ rule. Comparison of the present analysis with the
chiral-loop approach is given.


title: Stimulated Radiation of Particles in Crystallic Undulators

abstract:
  It is investigated the stimulated radiation which arises when the density and
energy of the beam of relativistic particles channeled in microscopic
crystallic undulators (CU) obtained by the application of transverse ultrasonic
(US) oscillations to single crystals, exceed certain values. For positron beams
expected at future linear colliders and real CU it is given the results of
numerical calculations for spontaneous and stimulated radiation.


title: Gluon topology and the spin structure of the constituent quark

abstract:
  Gluon topology makes a potentially important contribution to the spin of the
constituent quark.


title:
Improvement of perturbation theory in QCD for e^+e^- -> hadrons and the
  problem of \alpha_s freezing

abstract:
  We develope the method of improvement of perturbative theory in QCD, applied
to any polarization operator. The case of polarization operator \Pi(q^2),
corresponding to the process e^+e^- -> hadrons is considered in details. Using
the analytical properties of \Pi(q^2) and perturbative expansion of \Pi(q^2) at
q^2<0, Im\Pi(q^2) at q^2>0 is determined in such a way, that the infared pole
is eliminated. The convergence of perturbative series for R(q^2)=\sigma(e^+e^-
-> hadrons)/(e^+e^- -> \mu^+\mu^-) is improved. After substitution of R(q^2)
into dispersion relation the improved Adler function D(q^2) with no infrared
pole and frozen \alpha_s(q^2) has been obtained. A good agreement with
experiment has been achieved.


title: Jet Production by Real and Virtual Photons

abstract:
  The production of jets is studied in collisions of virtual photons,
specifically for applications at HERA. Photon flux factors are convoluted with
matrix elements involving either direct or resolved photons and, for the
latter, with parton distributions of the photon. Special emphasis is put on the
range of uncertainty in the modeling of the resolved component. The resulting
model is compared with existing data and further tests are proposed.


title:
RADGEN 1.0. Monte Carlo Generator for Radiative Events in DIS on
  Polarized and Unpolarized Targets

abstract:
  A new Monte-Carlo generator including real radiated photons in DIS on
polarized and unpolarized targets is presented. Analytical and numerical tests
are performed and discussed in details.


title: Exclusive evolution kernels in two-loop order: parity even sector

abstract:
  We complete the construction of the non-forward evolution kernels in
next-to-leading order responsible for the scale dependence of e.g. parity even
singlet distribution amplitudes. Our formalism is designed to avoid any
explicit two-loop calculations employing instead conformal and supersymmetric
constraints as well as known splitting functions.


title:
QED Radiative Effects in Diffractive Vector Meson Electro- and
  Photoproduction at HERA Energies

abstract:
  QED radiative corrections to the cross section of diffractive electro- and
photoproduction of vector mesons is calculated at HERA energies. Both
semi-analytical and Monte Carlo approaches are discussed and compared.


title: The semiclassical propagator in field theory

abstract:
  We consider scalar field theory in a changing background field. As an example
we study the simple case of a spatially varying mass for which we construct the
semiclassical approximation to the propagator. The semiclassical dispersion
relation is obtained by consideration of spectral integrals and agrees with the
WKB result. Further we find that, as a consequence of localization, the
semiclassical approximation necessarily contains quantum correlations in
momentum space.


title: Cluster Hadronization in HERWIG 5.9

abstract:
  The HERWIG 5.9 cluster hadronization model is briefly discussed here. It is
shown that the model has peculiar behaviour when new heavy baryon resonances
are included in the HERWIG 5.9 particle table. New fragmentation model is
proposed to cure this problem and simple tuning of HERWIG 5.9 with this new
model has been made using event shapes variables and identified particle
momentum spectra in electron-positron interactions at LEPI. Finally, the
predictions of the two hadronization models are compared.


title: Quantum Boltzmann equations for mixing scalar fields

abstract:
  We report on a work in progress, whose goal is a systematic field theoretical
derivation of the quantum transport equations for baryon production in the
electroweak plasma at a first order phase transition in the limit of slowly
varying background fields (thick wall limit). We start with the Schwinger-Dyson
equations for the two point Green function written in the closed time contour
(CTC) formalism. The quantum Boltzmann equations for the density matrix arise
when the SD-equations are expanded to the first order in the gradients in the
on-shell limit. In this paper we consider only scalar fields, but the formalism
can easily be extended to fermions.

categories: hep-ph cond-mat.stat-mech hep-th nucl-th


title: An Electroweak Model With Massive Neutrinos

abstract:
  In this paper, an electroweak model with massive neutrinos is proposed. The
symmetry of the model is $SU(2)_L \times U(1)_Y \times U(1)_M$. Because of the
mixing of neutrinos, the conversion of one lepton type to another is possible,
but many of those kind processes are of extremely small possibilities. The
total lepton-number conservation still holds in this model, so neutrinoless
double beta decay is prohibited. Though right-hand neutrinos are introduced
into the model, their coupling with matter fields is extremely small and
therefore they are much harder to be detected in experiments.


title:
Heavy quark 1/m_Q contributions in semileptonic B decays to orbitally
  excited D mesons

abstract:
  Exclusive semileptonic decays of B mesons to orbitally excited D mesons are
considered beyond the infinitely heavy quark limit in the framework of the
relativistic quark model based on the quasipotential approach. This model
agrees with the structure of heavy quark mass corrections predicted by the
heavy quark effective theory and allows the determination of corresponding
leading and subleading Isgur-Wise functions. It is found that both relativistic
and 1/m_Q contributions significantly influence the decay rates. Thus,
relativistic transformations of the meson wave functions (Wigner rotation of
the light quark spin) already contribute at leading order of the heavy quark
expansion and result in a suppression of B\to D^{*}_0e\nu and B\to D^{*}_1e\nu
decay rates. On the other hand, the vanishing of the decay matrix elements at
zero recoil of a final D^{**} meson in the infinitely heavy quark mass limit
makes the 1/m_Q corrections to be very important, and their account results in
a substantial enhancement of B\to D_1e\nu and B\to D^{*}_0e\nu decay rates.


title:
The non-perturbative corrections to the $\bar B \to X_s\gamma$ photon
  spectrum in a parton-like model

abstract:
  We derive a new parton-like formula, which establishes a simple connection
between the electroweak decay rate $\Gamma (\bar B \to X_s\gamma$) and the rate
of a free b-quark decay. The main features of our approach are the treatment of
the b-quark as an on-mass-shell particle and the inclusion of the effects
arising from the b-quark transverse motion in the $\bar B$-meson. Using various
b-quark light-front (LF) distribution functions, both phenomenological one and
the ones derived from current constituent quark models, and neglecting
perturbative corrections we compute the photon energy spectra and the moments
of the shape function. It is shown that the parton-like approach is fully
consistent with the Heavy Quark Effective Theory (HQET) provided the b-quark
constituent mass is redefined in the way similar to that used in HQET to define
the pole mass of the b quark. In this way the correction to first order in
$1/m_b$ can be eliminated from the total width in agreement with the general
statement of HQET. We have also found that the photon energy spectra calculated
in the LF approach agree well with the ones obtained in the ACM model, provided
the same distribution function is used as input in both cases. In spite of the
simplicity of the model our results show a fair good agreement both with the
HQET predictions and available experimental data.


title:
Out-of-equilibrium evolution of scalar fields in FRW cosmology:
  renormalization and numerical simulations

abstract:
  We present a renormalized computational framework for the evolution of a
self-interacting scalar field (inflaton) and its quantum fluctuations in an FRW
background geometry. We include a coupling of the field to the Ricci scalar
with a general coupling parameter $\xi$. We take into account the classical and
quantum back reactions, i.e., we consider the the dynamical evolution of the
cosmic scale factor. We perform, in the one-loop and in the large-N
approximation, the renormalization of the equation of motion for the inflaton
field, and of its energy momentum tensor. Our formalism is based on a
perturbative expansion for the mode functions, and uses dimensional
regularization. The renormalization procedure is manifestly covariant and the
counter terms are independent of the initial state. Some shortcomings in the
renormalization of the energy-momentum tensor in an earlier publication are
corrected. We avoid the occurence of initial singularities by constructing a
suitable class of initial states. The formalism is implemented numerically and
we present some results for the evolution in the post-inflationary preheating
era.


title:
Predictions for single spin asymmetries in lepton + p(transv. polarized)
  -> pion + X and gamma^* + p(transv. polarized) -> pion + X

abstract:
  Predictions for the single transverse spin asymmetry A_N in semi-inclusive
DIS processes are given; non negligible values of A_N may arise from spin
effects in the fragmentation of a polarized quark into a final hadron with a
transverse momentum k_T with respect to the jet axis, the so-called Collins
effect. The elementary single spin asymmetry of the fragmenting quark has been
fixed in a previous paper, by fitting data on p(transv. polarized) + P -> pion
+ X, and the predictions given here are uniquely based on the assumption that
the Collins effect is the only cause of the observed single spin asymmetries in
p(transv. polarized) + p -> pion + X. Eventual spin and k_T dependences in
quark distribution functions, the so-called Sivers effect, are also discussed.


title: Measuring the Top Quark Yukawa Coupling at a Linear e^+e^- Collider

abstract:
  The cross section for the reaction $e^+e^- \to t\bar{t} H$ depends
sensitively on the top quark Yukwawa coupling $\lambda_t$. We calculate the
rate for $t\bar{t}H$ production, followed by the decay $H\to b\bar{b}$, for a
Standard Model Higgs boson with 100 < m_H <130 GeV. We interface with ISAJET to
generate QCD radiation, hadronization and particle decays. We also calculate
the dominant $t\bar{t}b\bar{b}$ backgrounds from electroweak and QCD processes.
We consider both semileptonic and fully hadronic decays of the $t\bar{t}$
system. In our analysis, we attempt full reconstruction of the top quark and W
boson masses in the generated events. The invariant mass of the remaining
b-jets should show evidence of Higgs boson production. We estimate the accuracy
with which $\lambda_t$ can be measured at a linear e^+e^- collider. Our
results, including statistical but not systematic errors, show that the top
quark Yukawa coupling can be measured to 6-8 % accuracy with 1000 fb^{-1} at
$E_{CM}=1 TeV$, assuming 100 % efficiency for b-jet tagging. The accuracy of
the measurement drops to 17-22 % if only a 60 % efficiency for b-tagging is
achieved.


title: Bounds on Heavy-to-Heavy Mesonic Form Factors

abstract:
  We provide upper and lower bounds on the form factors for B -> D, D^* by
utilizing inclusive heavy quark effective theory sum rules. These bounds are
calculated to leading order in Lambda_QCD/m_Q and alpha_s. The O(alpha_s^2
beta_0) corrections to the bounds at zero recoil are also presented. We compare
our bounds with some of the form factor models used in the literature. All the
models we investigated failed to fall within the bounds for the combination of
form factors (omega^2 - 1)/(4 omega)|omega h_{A2}+h_{A3}|^2.


title: Searching for Strongly Interacting Massive Particles (SIMPs)

abstract:
  We consider laboratory experiments that can detect stable, neutral strongly
interacting massive particles (SIMPs). We explore the SIMP annihilation cross
section from its minimum value (restricted by cosmological bounds) to the barn
range, and vary the mass values from a GeV to a TeV. We calculate, as a
function of the SIMP-nucleon cross section, the minimum nucleon number A for
which there should be binding in a nucleus. We consider accelerator mass
spectrometry with a gold (A=200) target, and compute the likely abundance of
anomalous gold nuclei if stable neutral SIMPs exist. We also consider the
prospects and problems of detecting such particles at the Tevatron. We estimate
optimistically that such detection might be possible for SIMPs with
SIMP-nucleon cross sections larger than 0.1 millibarn and masses between 25 and
50 GeV.


title: Soft Gluon Effects on Electroweak Boson Production in Hadron Collisions

abstract:
  Shortened table of contents:
  1. Introduction
  1.1 The Standard Model of Elementary Particles
  1.2 The Quantum Nature of Gauge Fields
  2. Soft Gluon Resummation
  2.1 Lepton Pair Production at Fixed Order in $\alpha _s$
  2.2 The Resummation Formalism
  3. Vector Boson Production and Decay in Hadron Collisions
  3.1 Vector Boson Distributions
  3.2 Lepton Distributions
  4. Photon Pair Production In Hadronic Interactions
  4.1 Diphoton Production at Fixed Order
  4.2 Extension of the Resummation Formalism
  5. Gauge Boson Pair Production at the Upgraded Tevatron and at the LHC
  5.1 Introduction
  5.2 Analytical Results
  6. Charged Scalar Production at Hadron Colliders
  6.1 Introduction
  6.2 Charged (Pseudo-)Scalar Production via Charm-Bottom Fusion
  6.3 Soft Gluon Resummation
  6.4 Hadronic Decays of Charged (Pseudo-)Scalars to $O(\alpha _s)$
  6.5 Neutral (Pseudo-)Scalar Production via $b \bar b$ Fusion
  A. Probing Higgs Bosons with Large Bottom Yukawa Coupling at Hadron Colliders
  B. ``Intrinsic $k_T$'' and Soft Gluon Resummation


title: Light-Front-Quantized QCD in Covariant Gauge

abstract:
  The light-front (LF) canonical quantization of quantum chromodynamics in
covariant gauge is discussed. The Dirac procedure is used to eliminate the
constraints in the gauge-fixed front form theory quantum action and to
construct the LF Hamiltonian formulation. The physical degrees of freedom
emerge naturally. The propagator of the dynamical $\psi_+$ part of the free
fermionic propagator in the LF quantized field theory is shown to be causal and
not to contain instantaneous terms. Since the relevant propagators in the
covariant gauge formulation are causal, rotational invariance---including the
Coulomb potential in the static limit---can be recovered, avoiding the
difficulties encountered in light-cone gauge. The Wick rotation may also be
performed allowing the conversion of momentum space integrals into Euclidean
space forms. Some explicit computations are done in quantum electrodynamics to
illustrate the equivalence of front form theory with the conventional covariant
formulation. LF quantization thus provides a consistent formulation of gauge
theory, despite the fact that the hyperplanes $x^{\pm}=0$ used to impose
boundary conditions constitute characteristic surfaces of a hyperbolic partial
differential equation.


title: Flavor and Spin Structure of $\Lambda$-Baryon at Large x

abstract:
  It is shown that a perturbative QCD (pQCD) based analysis and the SU(6)
quark-diquark model give significant different predictions concerning the
flavor and spin structure for the quark distributions of the $\Lambda$-baryon
near $x=1$. Detailed predictions for the ratios $u(x)/s(x)$ of unpolarized
quark distributions, $\Delta s(x)/s(x)$ of valence strange quark, and $\Delta
u(x)/u(x)$ of valence up and down quarks of the $\Lambda$ are given from the
quark-diquark model and from a pQCD based model. It is found that the up and
down quarks are positively polarized at large $x$, even though their net spin
contributions to the $\Lambda$ might be zero or negative. The significant
difference for $u(x)/s(x)$ between the two different approaches are predicted.
The prediction of positively polarized up and down quarks inside the $\Lambda$
at large $x$ has been supported by the available data of $\Lambda$-polarization
in $Z$ decays and also by the most recent HERMES result of spin transfer to the
$\Lambda$ in deep elastic scattering of polarized lepton on the nucleon target.


title:
The definition of a magnetic monopole in Electrodynamics combined with
  Gravitation

abstract:
  It is discussed the singular string associated to the gauge field of
monopoles must be a physical observable if the monopole charge is different
from zero. It is naturally found that if the gauge is to be an observable, it
is possibly connected to gravity.


title: Parallelizing the Symbolic Manipulation Program FORM

abstract:
  After an introduction to the sequential version of FORM and the mechanisms
behind it we report on the status of our ongoing project of its
parallelization. An analysis of the parallel platforms used is given and the
structure of a parallel prototype of FORM is explained.


title: Supersymmetric Quintessence

abstract:
  Recent data point in the direction of a cosmological constant dominated
universe. We investigate the role of supersymmetric QCD with N_f < N_c as a
possible candidate for dynamical cosmological constant (``quintessence''). We
take in full consideration the multi-scalar nature of the model, allowing for
different initial conditions for the N_f independent scalar VEVs and studying
the coupled system of N_f equations of motion. The issues related to the
coupling of the scalars with other cosmological fields are also addressed.


title: A New Approach to Nuclear Collisions at RHIC Energies

abstract:
  We present a new parton model approach for nuclear collisions at RHIC
energies (and beyond). It is a selfconsistent treatment, using the same
formalism for calculating cross sections like the total and the inelastic one
and, on the other hand, particle production. Actually, the latter one is based
on an expression for the total cross section, expanded in terms of cut Feynman
diagrams. Dominant diagrams are assumed to be composed of parton ladders
between any pair of nucleons, with ordered virtualities from both ends of the
ladder.


title:
The CP violating phase \delta_{13} and the quark mixing angles
  \theta_{13}, \theta_{23} and \theta_{12} from flavour permutational symmetry
  breaking

abstract:
  The phase equivalence of the theoretical mixing matrix ${\bf V}^{th}$ derived
from the breaking of the flavour permutational symmetry and the standard
parametrization ${\bf V}^{PDG}$ advocated by the Particle Data Group is
explicitly exhibited. From here, we derive exact explicit expressions for the
three mixing angles $\theta_{12}$, $\theta_{13}$, $\theta_{23}$, and the CP
violating phase $\delta_{13}$ in terms of the quark mass ratios $(m_{u}/m_{t},
m_{c}/m_{t}, m_{d}/m_{b}, m_{s}/m_{b})$ and the parameters $Z^{*1/2}$ and
$\Phi^*$ characterizing the preferred symmetry breaking pattern. The computed
values for the CP violating phase and the mixing angles are:
  $\delta^*_{13}=75^\circ$, $\sin\theta^*_{12}=0.221$,
$\sin\theta^*_{13}=0.0034$, and $\sin\theta^*_{23}=0.040$, which coincide
almost exactly with the central values of the experimentally determined
quantities.


title: False Vacuum Decay in QCD within an Effective Lagrangian Approach

abstract:
  In an effective Lagrangian approach to QCD we nonperturbatively calculate an
analytic approximation to the decay rate of a false vacuum per unit volume,
$\Gamma/V$. We do so for both zero and high temperature theories. This result
is important for the study of the early universe at around the time of the QCD
phase transition. It is also important in order to determine the possibility of
observing this false vacuum decay at the Relativistic Heavy Ion Collider
(RHIC). Previously described dramatic signatures of the decay of false vacuum
bubbles would occur in our case as well.


title:
Gauge Coupling Unification with Extra Dimensions and Correction due to
  Higher Dimensional Operators

abstract:
  We study the gauge coupling unification with extra dimensions. We take into
account corrections due to the higher dimensional operators. We show the
prediction of $\alpha_3(M_Z)$ is sensitive to such corrections, even if
$c<\Phi>/M=O(0.01)$. We also discuss the $b-\tau$ Yukawa unification.


title: Multibaryons as Symmetric Multiskyrmions

abstract:
  We study non-adiabatic corrections to multibaryon systems within the bound
state approach to the SU(3) Skyrme model. We use approximate ansatze for the
static background fields based on rational maps which have the same symmetries
of the exact solutions. To determine the explicit form of the collective
Hamiltonians and wave functions we only make use of these symmetries. Thus, the
expressions obtained are also valid in the exact case. On the other hand, the
inertia parameters and hyperfine splitting constants we calculate do depend on
the detailed form of the ansatze and are, therefore, approximate. Using these
values we compute the low lying spectra of multibaryons with B <= 9 and
strangeness 0, -1 and -B. Finally, we show that the non-adiabatic corrections
do not affect the stability of the tetralambda and heptalambda found in a
previous work.


title: SO(10) GUT and Quark-Lepton Mass Matrices

abstract:
  The phenomenological model that all quark and lepton mass matrices have the
same zero texture, namely their (1,1), (1,3) and (3,1) components are zeros, is
discussed in the context of SO(10) Grand Unified Theories (GUTs). The mass
matrices of type I for quarks are consistent with the experimental data in the
quark sector. For the lepton sector, consistent fitting to the data of neutrino
oscillation experiments force us to use the mass matrix for the charged leptons
which is slightly deviated from type I. Given quark masses and charged lepton
masses, the model includes 19 free parameters, whereas the SO(10) GUTs gives 16
constrained equations. Changing the remaining three parameters freely, we can
fit all the entries of the CKM quark mixing matrix and the MNS lepton mixing
matrix, and three neutrino masses consistently with the present experimental
data.


title: Analysis of \epsilon'/\epsilon in the 1/N_c Expansion

abstract:
  We present a new analysis of the ratio \epsilon'/\epsilon which measures the
direct CP violation in K\to\pi\pi decays. We use the 1/N_c expansion within the
framework of the effective chiral lagrangian for pseudoscalar mesons. The 1/N_c
corrections to the hadronic matrix elements of all operators are calculated at
leading order in the chiral expansion. Numerically, doing a simple scanning of
the input parameters we find 1.5 \cdot 10^{-4}\leq \epsilon'/\epsilon \leq
31.6\cdot 10^{-4}. We also investigate, in the chiral limit, the 1/N_c
corrections to the operator Q_6 at next-to-leading order in the chiral
expansion. We find large positive corrections which can further enhance
\epsilon'/\epsilon and bring the standard model prediction close to the
measured value for central values of the parameters. Our result indicates that
a \Delta I=1/2 enhancement may be operative for Q_6 similar to the one of Q_1
and Q_2 which dominate the CP conserving amplitude.


title:
Spontaneous Breaking of Flavor Symmetry and Naturalness of Nearly
  Degenerate Neutrino Masses and Bi-maximal Mixing

abstract:
  The gauge model with $SO(3)_{F}$ flavor symmetry and three Higgs triplets is
studied. We show how the intriguing nearly degenerate neutrino mass and
bi-maximal mixing scenario comes out naturally after spontaneous breaking of
the symmetry. The hierarchy between the neutrino mass-squared differences,
which is needed for reconciling both solar and atmospheric neutrino data, is
naturally resulted from an approximate permutation symmetry. The model can also
lead to interesting phenomena on lepton-flavor violations via the $SO(3)_{F}$
gauge interactions.


title: What can we learn from the Caldwell plot?

abstract:
  We show that when screening corrections are included $ \frac{\partial
F_{2}(x,Q^{2})}{\partial \ln Q^{2}}$ is consistent with the behaviour that one
expects in pQCD. Screening corrections explain the enigma of the Caldwell plot.


title:
Error estimates for pi-pi scattering threshold parameters in Chiral
  Perturbation Theory to two loops

abstract:
  Using the analysis of ChPT to two loops, we perform an error analysis of the
threshold and low energy parameters, based on the uncertainties for the one
loop low energy parameters and the resonance saturation mechanism. Different
sets of one loop low energy constants have been considered.Thus, the predictive
power of the effective field theory is quantified on the basis of the present
experimental uncertainties.


title:
Lower limits for E_T and N_ch from pQCD & hydrodynamics at the central
  rapidity unit in central Au-Au collisions at RHIC

abstract:
  Final state average transverse energy and charged particle multiplicity at
the central rapidity unit of central Au-Au collisions at RHIC are studied
within a framework of lowest order perturbative QCD and Bjorken's
hydrodynamical picture. In particular, effects of initial minijet production
and the $pdV$ work during the subsequent evolution of the QGP are investigated.
Nuclear shadowing effects are included in a consistent manner, and the
dependence of the results on the minijet transverse momentum cut-off parameter
$p_0$ is shown.


title:
Estimation of the particle-antiparticle correlation effect for pion
  production in heavy ion collisions

abstract:
  Estimation of the back-to-back pi-pi correlations arising due to evolution of
the pionic field in the course of pion production process is given for central
heavy nucleus collisions at moderate energies.


title:
Double-logarithmic asymptotics of the magnetic form factor of electron
  and quark

abstract:
  The asymptotical behaviour of the magnetic form factor for electron and quark
is obtained in the double-logarithmic approximation for the Sudakov kinematics,
i.e. for the case when the value of the transfer momentum is much greater than
the mass of the particle.


title:
QCD Instanton-induced Processes in Deep-Inelastic Scattering - Search
  Strategies and Model Dependencies

abstract:
  We investigate possible search strategies for QCD-instanton induced processes
at HERA in the deep-inelastic scattering (DIS) regime. Our study is based on
the Monte Carlo generator QCDINS for instanton-induced events and the standard
generators for normal DIS events. It appears possible to isolate an instanton
enriched data sample via an optimized multi-dimensional cut scenario for a set
of six most instanton-sensitive DIS observables. As a further central point, we
investigate the stability of our results with respect to a variation of the
(hadronization) models available for the simulation of both normal DIS and
instanton-induced events. Dependencies on the variation of certain inherent
parameters are also studied. Within the ``bandwidth'' of variations considered,
we find that the normal DIS background is typically much more sensitive to
model variations than the I-induced signal.


title: On the possible space-time fractality of the emitting source

abstract:
  Using simple space-time implementation of the random cascade model we
investigate numerically a conjecture made some time ago which was joining the
intermittent behaviour of spectra of emitted particles with the possible
fractal structure of the emitting source. We demonstrate that such details are
seen, as expected, in the Bose-Einstein correlations between identical
particles. \\


title:
What have we learned and want to learn from heavy ion collisions at CERN
  SPS?

abstract:
  The talk is a mini-review of the current status of the field, with emphasis
on SPS heavy ion program, now and beyond 2000 (as asked by the organizers). The
main question is, of course, whether we can convince ourselves and the
community at large that the QGP is in fact produced at SPS. We came a long way
toward the positive answer, and are definitely on strongly rising part of the
learning curve. Still, in few key directions we lack important pieces of
evidences.


title:
Twist-4 contribution to unpolarized structure functions F_L and F_2 from
  instantons

abstract:
  We compute in the instanton vacuum the nucleon matrix elements of the twist-4
QCD operators describing power corrections to the second moments of the
unpolarized structure functions, F_L and F_2. Our approach takes into account
the leading contribution in the packing fraction of the instanton medium, rho /
R << 1. Parametrically leading are the matrix elements of a twist-4 quark-gluon
operator, which are of the order of the inverse instanton size, 1/rho^2 = (600
MeV)^2. The matrix elements of the four-fermion (diquark) operators are
suppressed by a factor (rho / R)^4 and numerically small. These results are in
agreement with the pattern of phenomenological 1/Q^2-corrections to R = sigma_L
/ sigma_T and F_2 found in QCD fits to the data. In particular, the rise of R
at low Q^2 can be obtained from instanton-type vacuum fluctuations at a low
scale.


title:
Conformal Phase Transition and Fate of the Hidden Local Symmetry in
  Large N_f QCD

abstract:
  It is observed that the Hidden Local Symmetry (HLS) for the vector mesons in
the ordinary QCD with smaller N_f plays the role of the "Higgsed magnetic gauge
symmetry" for the Seiberg duality in the SUSY QCD. For large N_f where the
conformal phase transition with chiral restoration and deconfinement is
expected to take place, we find that the HLS model also exhibits the chiral
restoration by the loop corrections (including the quadratic divergence) in a
manner similar to that in the CP^{N-1} model, provided that the bare HLS
Lagrangian respects the Georgi's vector limit at a certain N_f (\approx 7).


title:
$\mu \to e \gamma$ and $\mu \to 3e$ processes with polarized muons and
  supersymmetric grand unified theories

abstract:
  $\mu^{+} \to e^{+} \gamma$ and $\mu^{+} \to e^{+}e^{+}e^{-}$ processes are
analyzed in detail with polarized muons in supersymmetric grand unified
theories. We first present Dalitz plot distribution for $\mu^{+} \to
e^{+}e^{+}e^{-}$ decay based on effective Lagrangian with general
lepton-flavor-violating couplings and define various P- and T-odd asymmetries.
We calculate branching ratios and asymmetries in supersymmetric SU(5) and
SO(10) models taking into account complex soft supersymmetry breaking terms.
Imposing constraints from experimental bounds on the electron, neutron and
atomic electric dipole moments, we find that the T-odd asymmetry for $\mu^{+}
\to e^{+}e^{+}e^{-}$ can be 15% in the SU(5) case. P-odd asymmetry with respect
to muon polarization for $\mu^{+} \to e^{+} \gamma$ varies from -20% to -100%
for the SO(10) model while it is $+100%$ in the SU(5) case. We also show that
the P-odd asymmetries in $\mu^{+} \to e^{+}e^{+}e^{-}$ and the ratio of
$\mu^{+} \to e^{+}e^{+}e^{-}$ and $\mu^{+} \to e^{+} \gamma$ branching
fractions are useful to distinguish different models.


title:
Determination of cosmological parameters: an introduction for
  non-specialists

abstract:
  I start by defining the cosmological parameters $H_0, \Omega_m$ and
$\Omega_\Lambda$. Then I show how the age of the universe depends on them,
followed by the evolution of the scale parameter of the universe for various
values of the density parameters. Then I define strategies for measuring them,
and show the results for the recent determination of these parameters from
measurements on supernovas of type 1a. Implications for particle physics is
briefly discussed at the end.


title:
Reactions gamma gamma -> pi pi and gamma gamma -> K \bar K: the
  (IJ^{PC}=00^{++})-wave spectra at E_{gamma gamma}^{(c.m.)} = 300- 1900 MeV

abstract:
  We calculate the $00^{++}$-wave two-meson spectra for the reactions
$\gamma\gamma\to\pi^0\pi^0$, $\gamma\gamma\to\pi^+\pi^-$, $\gamma\gamma\to
K^0\bar K^0$ and $\gamma\gamma\to K^+ K^-$ on the basis of: (i) the results of
the $K$-matrix analysis of the $00^{++}$ amplitudes for the reactions $\pi\pi
\to \pi\pi$, $K\bar K$, $\eta\eta$, $\eta\eta'$, $\pi\pi\pi\pi $, and (ii)
recently developed method for calculation of the decay amplitudes
$f_0(1^3P_0q\bar q)\to \gamma\gamma$, $f_0(2^3P_0q\bar q)\to \gamma\gamma$. The
reconstructed $\pi\pi $ and $K\bar K$ spectra can be used as a guide for the
extraction of partial widths of scalar/isoscalar resonances $f_0(980)\to
\gamma\gamma$, $f_0(1300)\to \gamma\gamma$, $f_0(1500)\to \gamma\gamma$,
$f_0(1750)\to \gamma\gamma$. As follows from our calculations, the resonances
$f_0(980)$ and $f_0(1500)$ in the $\pi^+\pi^-$ and $\pi^0\pi^0$ spectra reveal
themselves as dips.


title:
Neutrino-Oxygen interactions: role of nuclear physics in the atmospheric
  neutrino anomaly

abstract:
  The apparent anomaly in the ratio of muon to electron atmospheric neutrinos
first observed by Kamiokande and IMB has been confirmed by Super-Kamiokande and
Soudan-2. The experimental analysis, including the asymmetry in the zenithal
distributions of the $ \mu-\mathrm{type} $ events in Super-Kamiokande gives a
strong support to the neutrino oscillation hypothesis to solve the anomaly.
  In this work we are interested by the role of nuclear physics in the
neutrino-oxygen reactions used to detect the atmospheric neutrinos. We point
out that multi-nucleon excitations of np-nh type and that nuclear correlations
could modify an experimental analysis \`a la Super-Kamiokande because they lead
to a substantial enhancement of the number of 1 \v{C}erenkov ring retained
events.


title:
Comments on atmospheric neutrino oscillation scenarios with large nu_mu
  <-> nu_e transitions

abstract:
  The evidence for $\nu_\mu$ disappearance in the Super-Kamiokande atmospheric
neutrino experiment and the negative searches for $\nu_e$ disappearance in the
CHOOZ reactor experiment can be easily reconciled by assuming oscillations with
large amplitude in the $\nu_\mu\leftrightarrow\nu_\tau$ channel and small (or
null) amplitude in the $\nu_\mu\leftrightarrow\nu_e$ channel. It has been
claimed, however, that some oscillation scenarios with large
$\nu_\mu\leftrightarrow\nu_e$ mixing can also be constructed in agreement with
the present data. We investigate quantitatively two such scenarios: (a)
threefold maximal mixing; and (b) attempts to fit all sources of evidence for
oscillations (solar, atmospheric, and accelerator) with three neutrinos. By
using mainly Super-Kamiokande data, we show that the case (a) is disfavored,
and that the case (b) is definitely ruled out.


title:
Quark recombination model for polarizations in inclusive hyperon
  productions at high energy

abstract:
  We investigate the transverse polarization of hyperons produced by the photon
induced reactions using the quark recombination model. This model reproduces
polarizations of hadrons produced by the hadron-hadron collisions and accounts
for the origin of the empirical rule by DeGrand and Miettinen. We find
significant polarizations in the hyperon photoproduction by applying this model
to the $\gamma N \ra \Lam $ $(\Sigma^{0}) + X$ reaction.


title:
On chaoticity of the amplification of the neutrino asymmetry in the
  early universe

abstract:
  We consider numerically the growth of neutrino asymmetry in active-sterile
neutrino oscillations in the early universe. It is shown that the final sign of
the asymmetry can be highly sensitive to small variations of the oscillation
parameters. We find regions which are completely or partially chaotic, but also
regions where the sign remains very robust. The consequences for atmospheric
neutrino oscillations and primordial nucleosynthesis are then discussed. In the
completely chaotic region the predicted He(4)-abundance has an inherent
arbitrariness \Delta Y \simeq 0.01.


title: Light Quarks Beyond Chiral Limit

abstract:
  In this talk we discuss an improvement of the Diakonov-Petrov QCD Effective
Action. We propose the Improved Effective Action, which is derived on the basis
of the Lee-Bardeen results for the quark determinant in the instanton field.
The Improved Effective Action provides proper account of the current quark
masses, which is particularly important for strange quarks. This Action is
successfully tested by the calculations of the quark condensate, the masses of
the pseudoscalar meson octet and by axial-anomaly low-energy theorems.


title:
Mass hierarchy of leptons and hadrons within the framework of
  electrodynamics

abstract:
  Structure of leptons and hadrons within the framework of electrodynamics is
considered. Muon and tau-lepton have the structure of 3 electrons. The mass of
muon is defined by the section of two-photon annihilation. The mass of
tau-lepton is defined by the section of three-photon annihilation. Hadrons are
characterized by the structure of 5 electrons. The masses of hadrons are
defined via the masses of muon and tau-lepton.


title:
Improved positivity bound for Deep Inelastic Scattering on transversely
  polarized nucleon

abstract:
  The positivity bound for the transverse asymmetry $A_2$ may be improved by
making use of the fact, that the state of a photon and a nucleon with total
spin 3/2, does not participate to the interference. The bound is therefore
useful in the case of a longitudinal asymmetry small (say, at low $x$) or
negative (like in the neuteron case).


title: Four-neutrino MS^2 mixing

abstract:
  We present a simple scheme of mixing of four neutrinos that can accommodate
the results of all neutrino oscillation experiments, the observed abundances of
primordial elements and the current upper bound for the effective Majorana
neutrino mass in neutrinoless double-beta decay (assuming that massive
neutrinos are Majorana particles). The scheme has maximal mixing in the
nu_mu,nu_tau-nu_3,nu_4 sector and small mixings in the nu_e,nu_s-nu_1,nu_2 and
nu_e,nu_mu-nu_1,nu_3 (or nu_e,nu_mu-nu_1,nu_4) sectors (MS^2). We discuss the
implications of this scheme for short and long baseline oscillation experiments
and for neutrinoless double-beta decay and tritium beta-decay experiments.


title: Quark propagator, instantons and gluon propagator

abstract:
  The Schwinger-Dyson formalism is used to check the consistency of instanton
model solutions for the quark propagator with recent models of confining gluon
propagators. We find that the models are not consistent. A major discrepancy is
the absence of a vector condensate in the instanton model that is present in
the solutions with nonperturbative confining gluons.


title: Muon (g-2) in models with a very light gravitino

abstract:
  We present the results of a general analysis of the contributions of the
supersymmetry-breaking sector to the muon anomalous magnetic moment in models
with a superlight gravitino. We find constraints on the model parameters that
are comparable and complementary to the ones coming from collider searches, and
will become more stringent after the Brookhaven E821 experiment.


title: Vector mesons in the Extended Chiral Quark Model

abstract:
  We extend our previous formulation of low-energy QCD in terms of an effective
lagrangian containing operators of dimensionality $d\le 6$ constructed with
pseudoscalars and quark fields, describing physics below the scale of chiral
symmetry breaking. We include in this paper the vector and axial-vector
channels. We follow closely the Extended Chiral Quark Model approach and
consistently work in the large-$N_c$ and leading log approximation and take
into account the constraints from chiral symmetry and chiral symmetry
restoration. The optimal fit of all parameters gives further support to a heavy
scalar meson with a mass $\sim 1$ GeV and a value of the axial pion-quark
coupling constant $g_A \simeq 0.55$ to 0.66, depending on some assumptions
concerning the Weinberg sum rules.


title: Remarks upon the mass oscillation formulas

abstract:
  The standard formula for mass oscillations is often based upon the
approximation $t \approx L$ and the hypotheses that neutrinos have been
produced with a definite momentum $p$ or, alternatively, with definite energy
$E$. This represents an inconsistent scenario and gives an unjustified
reduction by a factor of two in the mass oscillation formulas. Such an
ambiguity has been a matter of speculations and mistakes in discussing flavour
oscillations. We present a series of results and show how the problem of the
factor two in the oscillation length is not a consequence of gedanken
experiments, i.e. oscillations in time. The common velocity scenario yields the
maximum simplicity.


title: Top mixing

abstract:
  We discuss the existing limits on top flavour-changing neutral couplings in
models with new vector-like quarks. Large hadron and e+ e- colliders can
improve these bounds by more than one order of magnitude.


title:
Zt and \gamma t production via top flavour-changing neutral couplings at
  the Fermilab Tevatron

abstract:
  Associated single top production with a Z boson or a photon at large hadron
colliders provides a precise determination of top flavour-changing neutral
couplings. The best way to measure these couplings with the up quark at
Tevatron is to search for events with three jets and missing energy or events
with a photon, a charged lepton, a jet and missing energy. Other decay channels
are also discussed.


title: Long range neutrino forces in the cosmic relic neutrino background

abstract:
  Neutrinos mediate long range forces among macroscopic bodies in vacuum. When
the bodies are placed in the neutrino cosmic background, these forces are
modified. Indeed, at distances long compared to the scale $T^{-1}$, the relic
neutrinos completely screen off the 2-neutrino exchange force, whereas for
small distances the interaction remains unaffected.


title: The perturbative odderon intercept

abstract:
  We present our recent results on the odderon intercept in perturbative QCD,
obtained through the solution of the Baxter equation and investigation of the
spectrum of the relevant constant of motion.


title: Theory of Z boson decays

abstract:
  The precision data on Z boson decays from LEP-I and SLC colliders are
compared with the predictions based on the Minimal Standard Theory. The Born
approximation of the theory is based on three most accurately known
observables: G_mu -- the four fermion coupling constant of muon decay, m_Z --
the mass of the Z boson, and alpha(m_Z) -- the value of the running fine
structure constant at the scale of m_Z. The electroweak loop corrections are
expressed, in addition, in terms of the masses of higgs, m_H, of the top and
bottom quarks, m_t and m_b, and of the strong interaction constant
alpha_s(m_Z). The main emphasis of the review is focused on the
one-electroweak-loop approximation. Two electroweak loops have been calculated
in the literature only partly. Possible manifestations of new physics are
briefly discussed.


title: Why do we have parity violation?

abstract:
  We discuss here two of the questions posed at the beginning of the Bled 1998
workshop: Why is the weak charge dependent on handedness? Why do we have parity
violation in the Standard Model? It is argued that the quarks and leptons must
be protected from gaining a fundamental mass, very large compared to the
electroweak scale, by gauge invariance and hence that their gauge charges must
depend on handedness. Furthermore we argue that it is the conservation of
parity in the electromagnetic and strong interactions rather than parity
violation in the weak interactions that needs an explanation. We derive this
parity conservation and indeed the whole system of Weyl fermion representations
in the Standard Model from a few simple assumptions: Mass protection, small
representations, anomaly cancellation and the Standard Model gauge group
$S(U(2)\times U(3))$.


title: Higgs Physics at a \gamma \gamma Collider

abstract:
  High precision measurements of electroweak observables at $e^\pm$ colliders
indicate the existence of a light Higgs boson below the $W^\pm$ threshold. If
such a fundamental scalar should be found in the near future it is important to
fully investigate the electroweak symmetry braking sector of the Standard
Model. This is particularly important for an intermediate mass Higgs as its
existence might indicate physics beyond the Standard Model, for instance in
form of its minimal supersymmetric extension (MSSM). In this work we present
first results on the expected precision of the partial $\Gamma (H
\longrightarrow \gamma \gamma)$ width at the $\gamma \gamma$ option of a future
linear collider. This quantity is sensitive to new physics as heavy particles
do not decouple in general and differences between the SM and MSSM predictions
can differ by up to 10% even in the decoupling limit of large pseudoscalar
Higgs masses. This regime is difficult and for some values of $\tan \beta$
impossible to cover at the LHC. We find that the well understood background
process $\gamma \gamma \longrightarrow q \bar{q}$ allows for a ${\cal O} (2%)$
determination of $\Gamma (H \longrightarrow \gamma \gamma)$ using conservative
collider parameters.


title:
S-wave $\pi - \pi$ Scattering Lengths in the SU(2) NJL Model Beyond
  Mean-field Approximation

abstract:
  The S-wave $\pi - \pi$ scattering lengths $a_0$ and $a_2$ are calculated to
the lowest order of $1/N_c$ expansion in the general framework of SU(2) NJL
model beyond mean-field approximation. It is shown that using the universal
curve of $a_0$ and $a_2$ the four NJL parameters, i.e., the current quark mass
$m_0$, the four fermion coupling constant $G$, the quark momentum cut-off
$\Lambda_f$ and the meson momentum cut-off $\Lambda_b$, also the S-wave $\pi -
\pi$ scattering lengths in NJL model can be uniquely determined.


title: Status of the MSW Solutions to the Solar Neutrino Problem

abstract:
  We present an updated global analysis of two-flavor MSW solutions to the
solar neutrino problem in terms of conversions of nu_e into active or sterile
neutrinos. We perform a fit to the full data set corresponding to the 825-day
Super-Kamiokande data sample as well as to Chlorine, GALLEX and SAGE
experiments. We use all measured total event rates as well as Super-Kamiokande
data on the zenith angle dependence, energy spectrum and seasonal variation of
the events. For conversions into active neutrinos we find that, although the
data on the total event rates favours the Small Mixing Angle (SMA) solution,
once the full data set is included both SMA and Large Mixing Angle (LMA)
solutions give an equivalent fit to the data. The best-fit points for the
combined analysis are Delta m^2=3.6 10^{-5} eV^2 sin^2(2theta)=0.79 with
chi^2_min=35.4/30 d.o.f and Delta m^2=5.1~ 10^{-6} eV^2 and sin^2(2theta)=5.5
10^{-3} with chi^2_min=37.4/30 d.o.f. In contrast with the earlier 504-day
study of Bahcall-Krastev-Smirnov our results indicate that the LMA solution is
not only allowed, but slightly preferred. We also show that seasonal effects,
although small, may still reach 8.5 % at the best-fit LMA solution without
conflict with the hints of a day-night variation (6% is due to the eccentricity
of the Earth's orbit). For conversions into sterile neutrinos only the SMA
solution is allowed with best-fit point Delta m^2=5.0 10^{-6} eV^2 and
sin^2(2theta)=3. 10^{-3} and chi^2_min=40.2/30 d.o.f. We also consider
departures of the Standard Solar Model of Bahcall and Pinsonneault 1998 by
allowing arbitrary 8^B and hep fluxes. Best fit is obtained for
^8B/^8B_SSM=0.61 (1.37) and hep/hep_SSM=12 (38) for the SMA (LMA) solution.


title: Vacuum oscillations of quasi degenerate solar neutrinos

abstract:
  The atmospheric neutrino oscillations and the vacuum oscillation solution of
the solar neutrino problem can be consistently described by a doubly or triply
degenerate neutrino spectrum as long as the high level of degeneracy required
is not spoiled by radiative corrections. We show that this is the case for
neutrino mass matrices generated by symmetries. This imposes a strong
constraint on the mixing angles and requires the mixing should be close to
bi-maximal. We briefly discuss the relevance of our results for the
measurability of the neutrino spectrum.


title: Tensor polarization of vector mesons from quark and gluon fragmentation

abstract:
  We considered the electro- and photoproduction of \rho and other vector
mesons with moderately large transverse momentum in the scattering of
unpolarized electrons on unpolarized nucleons and nuclei. For these processes
we have analyzed how to extract the novel fragmentation functions \bar
b_1^q(z), \bar b_1^G(z), describing tensor polarization, and the photon double
spin-flip distribution \Delta^\gamma from the angular distribution of meson
decay products.


title: Supersymmetric Grand Unified Models without Adjoint Higgs Fields

abstract:
  We discuss two classes of supersymmetric grand unified theories based on
extended gauge groups $SO(10) \times SO(10)$ and $SO(10)\times SO(10)\times
SO(10)$. Effective adjoint fields of each gauge group SO(10) are argued to be
formed from combining two Higgs fields in fundamental representation of the
extended gauge groups, one obtaining its VEV along the diagonal $SO(10)_D$
direction and the other acquiring its VEV along the diagonal $SU(5)_D\times
U(1)_D$ or its subgroup direction. Thus experimentally acceptable fermion mass
matrices, such as Georgi-Jarlskog ansatz, with successful GUT mass relations
can be constructed in these theories.


title: Exclusive Lambda_b -> Lambda l^+ l^- decay in two Higgs doublet model

abstract:
  Rare Lambda_b -> Lambda l^+ l^- decay is investigated in framework of general
two Higgs doublet model, in which a new source of CP violation exists (model
III). The polarization parameter, CP asymmetry and decay width are calculated.
It is shown that CP asymmetry is a very sensitive tool for establishing model
III.


title: The Mass Effect in Quarkonium Decay

abstract:
  In the NRQCD factorization for productions and decays of a quakonium the
difference between the quarkonium mass and the twice of the heavy quark mass is
neglected at the leading order of the small velocity expansion. The effect of
this difference is included in the relativistic correction. We attempt to
define the difference in terms of NRQCD matrix elements and to separate the
effect of the difference in several decays. It turns out that the total
relativistic correcttion can be estimated by the difference. Numerically the
correction will enhance the decay widths considered here.


title:
The bottom $\bar{\rm MS}$ quark mass from sum rules at
  next-to-next-to-leading order

abstract:
  We determine the bottom $\bar{\rm MS}$ quark mass $\bar{m}_b$ and the quark
mass in the potential subtraction scheme from moments of the $b\bar{b}$
production cross section and from the mass of the Upsilon 1S state at
next-to-next-to-leading order in a reorganized perturbative expansion that sums
Coulomb exchange to all orders. We find $\bar{m}_b(\bar{m}_b)=(4.25\pm 0.08)
$GeV and $m_{b,\rm PS}(2 {GeV})=(4.59\pm 0.08) $GeV for the
potential-subtracted mass at the scale 2 GeV, adopting a conservative error
estimate.


title:
A two-loop application of the threshold expansion: the bottom quark mass
  from $b\bar{b}$ production

abstract:
  We use the threshold expansion and non-relativistic effective theory to
determine the bottom quark mass from moments of the $b\bar{b}$ production cross
section at next-to-next-to-leading order in the (resummed) perturbative
expansion, and including a summation of logarithms. For the $\bar{\rm MS}$ mass
$\bar{m}_b$, we find $\bar{m}_b(\bar{m}_b)=(4.26\pm 0.12)$ GeV.


title:
Alternative Form of the Parity-Violating Current for the Hyperon Weak
  Radiative Decays and Hara Theorem

abstract:
  It is shown that upon considering an alternative form of a parity-violating
part of the transition electromagnetic current it is possible to reformulate
Hara theorem in a way that it does not forbid any more nonzero asymmetry in the
hyperon weak radiative decays $\Sigma^{+} \to p+\gamma$ and $\Xi^{-} \to
\Sigma^{-}+\gamma$ in the limit of exact $SU(3)_{f}$ symmetry thus resolving a
contradiction with the data and maybe revealing hitherto unseen transition
toroid dipole moments. A result is consistent with the traditional one on the
single-quark weak radiative transition models. We have also reproduced Vasanti
formula at the quark level. As for two-quark weak radiative transitions we have
found that the important part of it contains also a toroid dipole moment
contribution which seems to be an intrinsic reason of the apparent
contradiction between the Hara theorem conclusion and quark model results for
hyperon weak radiative decays.


title: Schwinger-Dyson Approach to Color Superconductivity in Dense QCD

abstract:
  The problem of color superconductivity in dense QCD is reconsidered in the
improved rainbow approximation to the Schwinger-Dyson equation. The effect of
the unscreened magnetic modes of gluons on the value of the color condensate is
studied. In particular, it is shown that, at sufficiently large values of the
chemical potential, these modes lead to the enhancement of the superconducting
order parameter. The interplay between the instanton induced interaction and
the one-gluon induced one in color superconductivity is discussed.


title: Magnetic Moment of the $\Omega^-$ in QCD sumrule (QCDSR)

abstract:
  The $\Omega ^-$ magnetic moment was measured very accurately and
experimentalists remarked that it differs from the theoretical estimates, thus
posing a challenge to the latter. One such estimation uses QCDSR. We revisit
this sumrule method, using condensate parameters which were obtained from
fitting the differences ($\mu_p - \mu_n$), ($\mu_{\Sigma^+}- \mu_{\Sigma^-}$)
and ($\mu_{\Xi^0} - \mu_{\Xi^-}$) and confirm the experimental number. The
$\mu_{\Delta^{++}}$ is also found to agree with the experimental estimate.


title: Large Dimensions and String Physics at a TeV

abstract:
  Large extra dimensions, of size of order of TeV^{-1} ~= 10^{-16} cm, arise
naturally in the context of supersymmetry breaking in string theory, while
strings at a TeV scale offer a solution to the gauge hierarchy problem, as an
alternative to softly broken supersymmetry or technicolor. In this short
review, we present consistent perturbative realizations of string theories with
large volume compactifications and low string tensions, and discuss their main
physical implications.


title: Stability of the Lepton-Flavor Mixing Matrix Against Quantum Corrections

abstract:
  Recent neutrino experiments suggest the strong evidences of tiny neutrino
masses and the lepton-flavor mixing. Neutrino-oscillation solutions for the
atmospheric neutrino anomaly and the solar neutrino deficit can determine the
texture of neutrino mass matrix according to the neutrino mass hierarchies as
Type A: m_3 \gg m_2 \sim m_1, Type B: m_3 \ll m_2 \sim m_1, and Type C: m_3
\sim m_2 \sim m_1. In this paper we study the stability of the lepton-flavor
mixing matrix against quantum corrections for all types of mass hierarchy in
the minimal supersymmetric Standard Model with the effective dimension-five
operator which gives Majorana masses of neutrinos. The relative sign
assignments of neutrino masses in each type play the crucial roles for the
stability against quantum corrections. We find the lepton-flavor mixing matrix
of Type A is stable against quantum corrections, and that of Type B with the
same (opposite) signs of m_1 and m_2 are unstable (stable). For Type C, the
lepton-flavor-mixing matrix approaches to the definite unitary matrix according
to the relative sign assignments of neutrino mass eigenvalues, as the effects
of quantum corrections become large enough to neglect squared mass differences
of neutrinos.


title: The Transverse Cross Section in Exclusive Vector-Meson Production

abstract:
  We show that the ratio of the transverse to the longitudinal cross sections
observed at HERA cannot be reproduced by models which assume that the meson can
be described by an on-shell q qbar pair. We explain how a simple model allowing
off-shell (anti)quarks can naturally lead to agreement with experiment.


title: Inclusive Photon Production in Hadronic Collisions

abstract:
  High statistics fixed target and ISR inclusive photon production data are
compared to next-to-leading order (NLO) QCD calculations. The dependence of the
theoretical predictions on the structure functions, and on the theoretical
scales is investigated. It is shown that the data cannot be simultaneously
fitted with a single set of structure functions and scales. However, it is
argued that as long as one restricts the data/theory comparison to the xT range
where the theory is reliable, i.e. stable with respect to the scale variation,
there is no need to introduce an additional primordial kT dependence except for
Be data. Finally a precise determination of the strong coupling constant,
alpha_s, is performed from the direct photon production cross sections obtained
in high statistics pbar p and pp collisions at the CERN SPS (UA6) by a NLO QCD
analysis.


title: Nuclear Parton Distributions - a DGLAP Analysis

abstract:
  Nuclear parton distributions $f_A(x,Q^2)$ are studied within a framework of
the DGLAP evolution. Measurements of $F_2^A/F_2^D$ in deep inelastic $lA$
collisions, and Drell--Yan dilepton cross sections measured in $pA$ collisions
are used as constraints. Also conservation of momentum and baryon number is
required. It is shown that the calculated $Q^2$ evolution of $F_2^{\rm
Sn}/F_2^{\rm C}$ agrees very well with the recent NMC data, and that the ratios
$R_f^A=f_A/f$ are only moderately sensitive to the choice of a specific modern
set of free parton distributions. For general use, we offer a numerical
parametrization of $R_f^A(x,Q^2)$ for all parton flavours $f$ in $A>2$, and at
$10^{-6}\le x \le 1$ and $2.25 {\rm GeV}^2\le Q^2\le 10^4 {\rm GeV}^2$.


title: Ultrasoft Amplitudes in Hot QCD

abstract:
  By using the Boltzmann equation describing the relaxation of colour
excitations in the QCD plasma, we obtain effective amplitudes for the ultrasoft
colour fields carrying momenta of order $g^2 T$. These amplitudes are of the
same order in $g$ as the hard thermal loops (HTL), which they generalize by
including the effects of the collisions among the hard particles. The ultrasoft
amplitudes share many of the remarkable properties of the HTL's: they are gauge
invariant, obey simple Ward identities, and, in the static limit, reduce to the
usual Debye mass for the electric fields. However, unlike the HTL's, which
correspond effectively to one-loop diagrams, the ultrasoft amplitudes resum an
infinite number of diagrams of the bare perturbation theory. By solving the
linearized Boltzmann equation, we obtain a formula for the colour conductivity
which accounts for the contributions of the hard and soft modes beyond the
leading logarithmic approximation.


title: Lepton flavor mixing and baryogenesis

abstract:
  Recently a new general class of quark mass matrix ansatz has been proposed,
which originates from some flavor symmetry. We extend that symmetry to the
lepton sector and study the neutrino mass matrix and address the question of
the baryon asymmetry of the universe in this model.


title: Long Baseline Neutrino Physics with a Muon Storage Ring Neutrino Source

abstract:
  We examine the physics capabilities of known flavor neutrino beams from
intense muon sources. We find that long-baseline neutrino experiments based on
such beams can provide precise measurements of neutrino oscillation mass and
mixing parameters. Furthermore, they can test whether the dominant atmospheric
neutrino oscillations are \nu_\mu --> \nu_\tau and/or \nu_\mu --> \nu_s,
determine the \nu_\mu --> \nu_e content of atmospheric neutrino oscillations,
and measure \nu_e --> \nu_\tau appearance. Depending on the oscillation
parameters, they may be able to detect Earth matter and CP violation effects
and to determine the ordering of some of the mass eigenstates.


title: Flavor Asymmetries in the Proton and Semi-Inclusive Processes

abstract:
  Semi-inclusive electron scattering provides a powerful tool with which to
study the spin and flavor distributions in the proton. Greater kinematic
coverage at the proposed Electron-Polarized Ion Collider facility will enable
the valence d/u ratio to be determined at large x through pion production. At
small x, pion production can be used to extract the d-bar/u-bar ratio,
complementing existing semi-inclusive measurements by HERMES, and Drell-Yan
data from Fermilab. Asymmetries in heavier quark flavors can also be probed by
tagging strange and charm hadrons in the final state.


title:
The decay tau -> 3 pi + nu(tau) as a probe of the mechanism of dynamical
  chiral symmetry breaking

abstract:
  The decays tau -> 3 pi + nu(tau) are analyzed at one loop order in the
framework of Generalized Chiral Perturbation Theory, in order to test the
sensitivity to the size of spontaneous chiral symmetry breaking parameters,
contained in the S-wave. The latter, due to a kinematical suppression, at
threshold, of the P-wave, is relatively large enough to be detectable at high
energy machines, through azimuthal left-right asymmetries. This quantity (for
the pi- pi- pi+ mode), integrated from threshold to Q^2 = 0.35 GeV^2, varies
from (17 +- 3) % in the standard case of large condensate up to (40 +- 5) % in
the extreme case of tiny condensate. The feasibility of such measurement at
high luminosity colliders (e.g. CLEO) is discussed. This method provides a
completely independent cross-check of forthcoming experimental determination of
the quark condensate, based on low energy pi-pi scattering.