title:
Studies of the Vector-Meson Mass Generation Scheme by Chiral Anomalies
  in two-Dimensional non-Abelian Gauge Theories

abstract:
  Higher order effects of the two-dimensional non-Abelian gauge theories, in
which the vector-meson mass is generated by chiral anomalies, will be studied.
The $\beta$ function and the topological nature of the non-linear $\sigma$
model in the action and unitarity of the theory will be discussed.


title:
Formation of extended topological defects during symmetry breaking phase
  transitions in O(2) and O(3) models

abstract:
  The density of extended topological defects created during symmetry-breaking
phase transitions depends on the ratio between the correlation length in the
symmetric phase near $T_c$ and the winding length of the defects as determined
by the momentaneous effective action after a typical relaxation time.
Conservation of winding number in numerical simulations requires a suitable
embedding of the field variables and the appropriate geometrical implementation
of the winding density on the discrete lattice. We define a modified Kibble
limit for the square lattice and obtain defect densities as functions of
winding lengths in O(2) and O(3) models. The latter allows to observe formation
of disoriented aligned domains within the easy plane. Their extent is severely
limited by the momentaneous defect density during the course of the quench.


title:
Mass Differences within Isotopic Multiplets in a SUSY Electro-weak
  Theory

abstract:
  Based on the idea that electromagnetism is responsible for the mass
differences within isotopic multiplets, and possibly also for the whole mass of
the electron, a supersymmetric gauge theoretical model based on the group
$SU(2)_{L} \times SU(2)_{R} \times U(1)_{Y}$ is constructed. Under some
reasonable assumptions to the SUSY particle spectrum, a correct sign for the
mass difference within an isotopic multiplet is obtained. This might provide a
possible scenario to understand the old puzzle of the proton-neutron mass
difference.


title: Deeply Virtual Electroproduction of Photons and Mesons

abstract:
  In this paper, after a brief summary of the properties of the Off-Forward
Parton Distributions, we give some examples of what could be the experimental
opportunities to access them at the current high-energy lepton facilities :
JLab (E_e >= 6 GeV), HERMES (E_e = 27 GeV) and COMPASS (E_mu = 200 GeV).


title: Phenomenological Issues in TeV scale Gravity with Light Neutrino Masses

abstract:
  The possible existence of bulk singlet neutrinos in the scenario with large
compactified dimensions and low string scale $M_*$ has important consequences
for low-energy observables. We demonstrate that intergenerational mass
splitting and mixing lead to the effective violation of the lepton universality
and flavor changing processes in charged lepton sector. Current experimental
constraints push $M_*$ to the scale of 10 TeV over most of the interesting
range for neutrino mass splitting.


title: Supernova Neutrinos and the Neutrino Masses

abstract:
  Core-collapse supernovae emit of order $10^{58}$ neutrinos and antineutrinos
of all flavors over several seconds, with average energies of 10--25 MeV. In
the Sudbury Neutrino Observatory (SNO), a future Galactic supernova at a
distance of 10 kpc would cause several hundred events. The $\nu_\mu$ and
$\nu_\tau$ neutrinos and antineutrinos are of particular interest, as a test of
the supernova mechanism. In addition, it is possible to measure or limit their
masses by their delay (determined from neutral-current events) relative to the
$\bar{\nu}_e$ neutrinos (determined from charged-current events). Numerical
results are presented for such a future supernova as seen in SNO. Under
reasonable assumptions, and in the presence of the expected counting
statistics, a $\nu_\mu$ or $\nu_\tau$ mass down to about 30 eV can be simply
and robustly determined. This seems to be the best technique for direct
measurement of these masses.


title:
Nonsupersymmetric gauge coupling unfication in [SU(6)]$^4\times$ Z$_4$
  and proton stability

abstract:
  We systematically study the three family extension of the Pati-Salam gauge
group with an anomaly-free single irreducible representation which contains the
known quarks and leptons without mirror fermions. In the context of this model
we implement the survival hypothesis, the modified horizontal survival
hypothesis, and calculate the tree level masses for the gauge boson and fermion
fields. We also use the extended survival hypothesis in order to calculate the
mass scales using the renormalization group equation. The interacting
Lagrangean with all the known and predicted gauge interactions is explicitly
displayed. Finally the stability of the proton in this model is established.


title: D-term Inflation in Type I String Theory

abstract:
  D-term inflation realized in heterotic string theory has two problems: the
scale of the anomalous D-term is too large for accounting for COBE data and the
coupling constant of the anomalous U(1) is too large for supergravity to be
valid. We show that both of these problems can be easily solved in D-term
inflation based on type I string theory or orientifolds of type IIB strings.


title: Dynamical Breaking of CPT and Baryogenesis

abstract:
  The asymmetry between matter and antimatter in the Universe indicates that
there was a period in the very early Universe when the CPT symmetry was broken.
The conservative interpretation is that the breaking was dynamical, induced by
the distinguished direction of time stemming from the cosmological expansion.
Here, I review the role which topological defect networks may play in
baryogenesis and how this relates to dynamical CPT symmetry breaking.
Particular attention is placed on defect-mediated electroweak baryogenesis. A
recent suggestion of defect-mediated QCD scale baryogenesis is also mentioned.


title:
Longitudinal subtleties in diffusive Langevin equations for non-Abelian
  plasmas

abstract:
  Boedeker has recently argued that non-perturbative processes in very high
temperature non-Abelian plasmas (such as electroweak baryon number violation in
the very hot early Universe) can be quantitatively described, to leading
logarithmic accuracy, by a simple diffusive effective theory. Boedeker's
effective theory is intended to describe the long-distance transverse electric
and magnetic fields which are responsible for non-perturbative dynamics. His
effective theory, however, also contains long-wavelength longitudinal electric
fields. We discuss several subtleties in the treatment of longitudinal dynamics
which were not closely examined in Boedeker's original treatment. Somewhat to
our surprise, we find that within its domain of validity Boedeker's effective
theory does correctly describe both longitudinal and transverse fluctuations.
We also show that, as far as the transverse dynamics of interest is concerned,
Boedeker's effective theory could be replaced by a transverse-only theory that
removes the longitudinal dynamics altogether. In the process, we discuss
several interesting aspects of stochastic field theories.


title: A new mechanism for neutrino mass

abstract:
  A mechanism for generating massive but naturally light Dirac neutrinos is
proposed. It involves composite Higgs within the standard model as well as some
new interaction beyond the standard model. According to this scenario, a
neutrino mass of 0.1 eV or higher, signals new physics at energies of 10--100
TeV or lower.


title:
Resonant particle production with non-minimally coupled scalar fields in
  preheating after inflation

abstract:
  We investigate a resonant particle production of a scalar field $\chi$
coupled non-minimally to a spacetime curvature $R$ ($\xi R \chi^2$) as well as
to an inflaton field $\phi$ ($g^2\phi^2\chi^2$). In the case of $g < 3 \times
10^{-4}$, $\xi$ effect assists $g$-resonance in certain parameter regimes.
However, for $g > 3 \times 10^{-4}$, $g$-resonance is not enhanced by $\xi$
effect because of $\xi$ suppression effect as well as a back reaction effect.
If $\xi \approx -4$, the maximal fluctuation of produced $\chi$-particle is
$\sqrt{< \chi^2 >}_{max} \approx 2 \times 10^{17}$ GeV for $g < 1 \times
10^{-5}$, which is larger than the minimally coupled case with $g \approx 1
\times 10^{-3}$.


title: End point of the electroweak phase transition

abstract:
  We study the hot electroweak phase transition (EWPT) by 4-dimensional lattice
simulations on lattices with symmetric and asymmetric lattice spacings and give
the phase diagram. A continuum extrapolation is done. We find first order phase
transition for Higgs-boson masses $m_H<66.5 \pm 1.4$ GeV. Above this end point
a rapid cross-over occurs. Our result agrees with that of the dimensional
reduction approach. It also indicates that the fermionic sector of the Standard
Model (SM) may be included perturbatively. We get for the SM end point $72.4
\pm 1.7$ GeV. Thus, the LEP Higgs-boson mass lower bound excludes any EWPT in
the SM.


title: Relics of the Cosmological QCD Phase Transition

abstract:
  The abundance and size distribution of quark nuggets (QN), formed a few
microseconds after the big bang due to first order QCD phase transition in the
early universe, has been estimated. It appears that stable QNs could be a
viable candidate for cosmological dark matter. The evolution of baryon
inhomogeneity due to evaporated (unstable) QNs are also examined.


title: Cascade Decays in the NMSSM

abstract:
  We study unconventional signatures of the NMSSM (the MSSM with an additional
gauge singlet) with a singlino LSP. Compared to sparticle production processes
in the MSSM, these consist in additional cascades (one or two additional l+ l-,
tau+ tau- or b bbar pairs or photons), possibly with macroscopically displaced
vertices with distances varying from millimeters to several meters.


title: Electroweak Baryogenesis with Cosmic Strings ?

abstract:
  I report on a critical analysis of the scenario of electroweak baryogenesis
mediated by nonsuperconducting cosmic strings. This mechanism relies upon
electroweak symmetry restoration in a region around cosmic strings, where
sphalerons would be unsuppressed. I discuss the various problems this scenario
has to face, presenting a careful computation of the sphaleron rates inside the
strings, of the chemical potential for chiral number and of the efficiency of
baryogenesis in different regimes of string networks. The conclusion is that
the asymmetry in baryon number generated by this scenario is smaller than the
observed value by at least 10 orders of magnitude.


title:
Neutrino propagation and spin zero sound in hot neutron matter with
  Skyrme interactions

abstract:
  We present microscopic calculations of neutrino propagation in hot neutron
matter above nuclear density within the framework of the Random Phase
Approximation . Calculations are performed for non- degenerate neutrinos using
various Skyrme effective interactions. We find that for densities just above
nuclear density, spin zero sound is present at zero temperature for all Skyrme
forces considered. However it disappears rapidly with increasing temperature
due to a strong Landau damping. As a result the mean-free path is given, to a
good approximation, by the mean field value. Because of the renormalization of
the bare mass in the mean field, the medium is more transparent as compared to
the free case. We find, in contrast, that at several times nuclear density, a
new type of behavior sets in due to the vicinity of a magnetic instability. It
produces a strong reduction of the mean free path. The corresponding transition
density however occurs in a region where inputs from more realistic
calculations are necessary for the construction of a reliable Skyrme type
parametrization.


title: Finite temperature field theory and phase transitions

abstract:
  We review different aspects of field theory at zero and finite temperature,
related to the theory of phase transitions. We discuss different
renormalization conditions for the effective potential at zero temperature,
emphasizing in particular the MS-bar renormalization scheme. Finite temperature
field theory is discussed in the real and imaginary time formalisms, showing
their equivalence in simple examples. Bubble nucleation by thermal tunneling,
and the subsequent development of the phase transition is described in some
detail. Some attention is also devoted to the breakdown of the perturbative
expansion and the infrared problem in the finite temperature field theory.
Finally the application to baryogenesis at the electroweak phase transition is
done in the Standard Model and in the Minimal Supersymmetric Standard Model. In
all cases we have translated the condition of not washing out any previously
generated baryon asymmetry by upper bounds on the Higgs mass.


title:
Vector mesons $\rho, \rho'$ and $\rho''$ diffractively photo- and
  leptoproduced

abstract:
  In the framework of non-perturbative QCD we calculate high-energy diffractive
production of vector mesons $\rh, \rh'$ and $\rh''$ by real and virtual photons
on a nucleon. The initial photon dissociates into a $q\bar{q}$-dipole and
transforms into a vector meson by scattering off the nucleon which, for
simplicity, is represented as quark-diquark. The relevant dipole-dipole
scattering amplitude is provided by the non-perturbative model of the
stochastic QCD vacuum. The wave functions result from considerations in the
frame of light-front dynamics; the physical $\rh'$- and $\rh''$-mesons are
assumed to be mixed states of an active 2S-excitation and some residual rest
(2D- and/or hybrid state). We obtain good agreement with the experimental data
and get an understanding of the markedly different $\pi^+\pi^-$-mass spectra
for photoproduction and $e^+e^-$-annihilation.


title: Forward Jet Production at small x in Next-to-Leading Order QCD

abstract:
  The production of forward jets of transverse energy E_T\simeq Q and large
momentum fraction x_jet >> x is calculated in next-to-leading order including
consistently direct and resolved virtual photon contributions. The predictions
are compared to recent ZEUS and H1 data. Good agreement with the data is found.


title: Hard exclusive electroproduction of two pions and their resonances

abstract:
  We study the hard exclusive production of two pions in the virtual photon
fragmentation region with various invariant masses including the resonance
region. The amplitude is expressed in terms of two-pion light cone distribution
amplitudes ($2\pi$DA's). We derive dispersion relations for these amplitudes,
which enables us to fix them completely in terms of $\pi\pi$ scattering phases
and a few low-energy subtraction constants determind by the effective chiral
lagrangian. Quantitative estimates of the resonance as well $\pi\pi$ background
DA's at low normalization point are made. We also prove certain new soft pion
theorem relating two-pion DA's to the one-pion DA's. Crossing relations between
$2\pi$DA's and parton distributions in a pion are discussed. We demontrate that
by studying the \underline{shape} of the $\pi\pi$ mass spectra (not absolute
cross section!) in a diffractive electroproduction one can extract the
deviation of the meson ($\pi,\rho,$ etc.) wave functions from their asymptotic
form $6 z(1-z)$ and hence to get important information about the structure of
mesons. We suggest (alternative to S\"oding's) parametrization of $\pi\pi$
spectra which is suitable for large photon virtuality.


title:
Two Majorana Neutrino Mass Doublets with Thorough Maximal Doublet Mixing
  from an Analogy with the K^0-Meson Oscillations

abstract:
  In the recent note we argued that most of the available positive and negative
neutrino oscillation data can be incorporated in a four-neutrino weak
interaction model with one physical condition: thorough maximal mixing of the
neutrino components in each of the two mass doublets. On the level of
CP-invariance an extended Pontecorvo analogy between the neutrino oscillations
and the K^0-meson oscillations, which implied maximal violation of the lepton
charge conservation in the neutrino mass matrix exclusively, can afford a
physical clue to the three data dictated assumptions in a model with three
lepton flavors and only two 4-component neutrino generations: four
phenomenological neutrinos with two neutrino mass doublets, one sterile
neutrino in the oscillations, and thorough maximal neutrino doublet mixing.
This analogy predicts that all the four neutrino mass eigenstates are of the
Majorana type.


title:
Higher-order Results for Precision Observables in the Standard Model and
  the MSSM

abstract:
  Recent higher-order results for precision observables in the Standard Model
(SM) and the Minimal Supersymmetric Standard Model (MSSM) and for the neutral
CP-even Higgs-boson masses of the MSSM are summarized. Furthermore a brief
discussion of the technical aspects of evaluating higher-order corrections in
the electroweak theory is given. In the SM, results for the Higgs-mass
dependence of the precision observables are analyzed. The exact two-loop
results for the Higgs-mass dependence of the fermionic contributions are
compared with the results of an expansion in the top-quark mass up to
next-to-leading order. In the MSSM, results for the leading two-loop
contributions to the precision observables and to the masses of the neutral
CP-even Higgs bosons are discussed. The latter are compared with results
obtained by renormalization group calculations.


title: Predicting quark and lepton masses and mixings

abstract:
  A model is presented that fits the quark and lepton masses and mixings
wherein five dimensionless parameters and a phase account for fifteen
dimensionless observables. Among these are the Wolfenstein parameters $\rho$
and $\eta$, the $\nu_e-\nu_{\mu}$ and $\nu_e-\nu_{\tau}$ mixing angles which
are predicted to be small and comparable while the $\nu_{\mu}-\nu_{\tau}$
mixing angle is predicted to be large. The model is based on supersymmetric
SO(10) with the form of the mass matrices motivated by simplicity at the level
of grand unification.


title: Metric preheating and limitations of linearized gravity

abstract:
  Recently it has become clear that the resonant amplification of quantum field
fluctuations at preheating must be accompanied by resonant amplification of
scalar metric perturbations, since the two are united by Einstein's equations.
Furthermore, this "metric preheating" enhances particle production and leads to
gravitational rescattering effects even at linear order. In multi-field models
with strong preheating (q \gg 1), metric perturbations are driven nonlinear,
with the strongest amplification typically on super-Hubble scales (k \to 0).
This amplification is causal, being due to the super- Hubble coherence of the
inflaton condensate, and is accompanied by resonant growth of entropy
perturbations. The amplification invalidates the use of the linearized Einstein
field equations, irrespective of the amount of fine-tuning of the initial
conditions. This has serious implications at all scales - from the large-angle
cosmic microwave background (CMB) anisotropies to primordial black holes. We
investigate the (q,k) parameter space in a two-field model, and introduce the
time to nonlinearity, t_{nl}, as the timescale for the breakdown of the
linearized Einstein equations. Backreaction effects are expected to shut down
the linear resonances, but cannot remove the existing amplification, which
threatens the viability of strong preheating when confronted with the CMB. We
discuss ways to escape the above conclusions, including secondary phases of
inflation and preheating solely to fermions. Finally we rank known classes of
inflation from strongest (chaotic and strongly coupled hybrid inflation) to
weakest (hidden sector, warm inflation) in terms of the distortion of the
primordial spectrum due to these resonances in preheating.


title:
Two/Three-Flavor Oscillation and MSW/Vacuum Oscillation Solution of
  Neutrinos in the SO(3) Gauge Model

abstract:
  Three interesting scenarios for neutrino mixing, i.e., (i) small-large mixing
scenario, (ii) nearly bi-maximal mixing scenario and (iii) three-flavor
oscillation scenario, are analyzed in connection with three possible
assignments of the maximal CP-violating phase after spontaneous symmetry
breaking of SO(3) in a model with gauged SO(3) lepton flavor symmetry. As a
consequence, it is found that the scenario (ii) is more reliable to be resulted
in reconciling both solar and atmospheric neutrino data. Though three Majorana
neutrino masses in all scenarios can be nearly degenerate, in the scenarios
(ii) and (iii) masses of the neutrinos are allowed to be large enough to play a
significant cosmological role and in the scenario (i) the fraction
$\Omega_{\nu}/\Omega_{m}$ is bounded to be $\Omega_{\nu}/\Omega_{m} < (4-10)%$
for $\Omega_{m} = (1.0-0.4)$ and $h=0.6$.


title: Strange Asymmetries in the Nucleon Sea

abstract:
  Relativistic corrections to the strange axial form factor are evaluated
within a light-cone formalism, taking into account effects due to the breaking
of Lorentz covariance associated with the use of one-body currents. Similar
corrections are known to also be needed for the magnetic form factor, and we
discuss the importance of these for recent data on strange electromagnetic form
factors from the HAPPEX Collaboration at Jefferson Lab. The strange vector form
factors, the strange axial charge, and the asymmetries in strange quark
distributions are shown to be consistently correlated within the chiral cloud
model.


title:
The Infrared Behavior of Gluon, Ghost, and Quark Propagators in Landau
  Gauge QCD

abstract:
  A truncation scheme for the Dyson-Schwinger equations of QCD in Landau gauge
is presented which implements the Slavnov-Taylor identities for the 3-point
vertex functions. Neglecting contributions from 4-point correlations such as
the 4-gluon vertex function and irreducible scattering kernels, a closed system
of equations for the propagators is obtained. For the pure gauge theory without
quarks this system of equations for the propagators of gluons and ghosts is
solved in an approximation which allows for an analytic discussion of its
solutions in the infrared: The gluon propagator is shown to vanish for small
spacelike momenta whereas the ghost propagator is found to be infrared
enhanced. The running coupling of the non-perturbative subtraction scheme
approaches an infrared stable fixed point at a critical value of the coupling,
$\alpha_c \simeq 9.5$. The gluon propagator is shown to have no Lehmann
representation. The gluon and ghost propagators obtained here compare favorably
with recent lattice calculations. Results for the quark propagator in the
quenched approximation are presented.


title: Inclusive decays and lifetimes of doubly charmed baryons

abstract:
  The analysis of singly charmed hadrons has been extended to the case of
doubly charmed baryons, $\Xi_{cc}^{++}$, $\Xi_{cc}^{+}$ and $\Omega_{cc}^{+}$.
Doubly charmed baryons are described as a system containing a heavy
$cc$-diquark and a light quark, similarly as in a heavy-light meson. This leads
to preasymptotic effects in semileptonic and nonleptonic decays which are
essentially proportional to the meson wave function. Interplay between
preasymptotic effects in semileptonic and/or nonleptonic decay rates leads to
very clear predictions for semileptonic branching ratios and lifetimes of
doubly charmed baryons.


title: A Quark Model Analysis of Orbital Angular Momentum

abstract:
  Orbital Angular Momentum (OAM) twist-two parton distributions are studied. At
the low energy, hadronic, scale we calculate them for the relativistic MIT bag
model and for non-relativistic potential quark models. We reach the scale of
the data by leading order evolution using the OPE and perturbative QCD. We
confirm that the contribution of quarks and gluons OAM to the nucleon spin
grows with $Q^2$, and it can be relevant at the experimental scale, even if it
is negligible at the hadronic scale, irrespective of the model used. The sign
and shape of the quark OAM distribution at high $Q^2$ may depend strongly on
the relative size of the OAM and spin distributions at the hadronic scale.
Sizeable quark OAM distributions at the hadronic scale, as proposed by several
authors, can produce the dominant contribution to the nucleon spin at high
$Q^2$. As expected by general arguments, we obtain, that the large gluon OAM
contribution is almost cancelled by the gluon spin contribution.


title: Charged Higgs and Scalar Couplings in Semileptonic Meson Decay

abstract:
  We present a new charged Higgs search technique using the effects of scalar
dynamics in semileptonic meson decay. Applying this method to a modest sample
of B meson decays yields sensitivity to the high tan(beta) region well beyond
existing charged Higgs searches. We present a new charged Higgs search
technique using the effects of scalar dynamics in semileptonic meson decay.
Applying this method to a modest sample of B meson decays yields sensitivity to
the high tan(beta) region well beyond existing charged Higgs searches.


title: Bubble Wall Profiles in Supersymmetric Models

abstract:
  We present solutions to the equations of motion for bubble wall profiles in
the minimal and a non minimal supersymmetric extension of the Standard model.
We discuss the method of the numerical approach and present results for the two
models (MSSM and NMSSM). Calculations for the NMSSM were done in collaboration
with S.J. Huber and M.G. Schmidt.


title: A large final-state interaction in the 0-0- decays of J/psi

abstract:
  In view of important implications in the B decay, the 0-0- decay modes of
J/psi are analyzed with broken flavor SU(3) symmetry in search for
long-distance final-state interactions. If we impose one mild theoretical
constraint on the electromagnetic form factors, we find that a large phase
difference of final-state interactions is strongly favored between the
one-photon and the gluon decay amplitudes. Measurement of the \pi+\pi- and K+K-
cross sections off the J/psi peak in e+e- annihilation can settle the issue
without recourse to theory.


title:
Diffractive $J/\psi$ production through color-octet mechanism in
  resolved photon processes at HERA

abstract:
  We use the color-octet mechanism combined with the two gluon exchange model
for the diffractive $J/\psi$ production in resolved photon processes. In the
leading logarithmic approximation in QCD, we find that the diffractive $J/\psi$
production cross section is related to the off-diagonal gluon density of the
proton, the gluon density of the photon and to the nonperturbative color-octet
$^3 S_{1}^{(8)}$ matrix element of $J/\psi$. The cross section is found to be
very sensitive to the gluon density of the photon. As a result, this process
may provide a wide window for testing the two-gluon exchange model, studying
the nature of hard diffractive factorization breaking and may be particularly
useful in studying the gluon distribution of the photon. And it may also be a
golden place to test the color-octet mechanism proposed by solving the
$\psi'(J/\psi)$ surplus problem at the Tevatron.


title:
Flavor Symmetry, K^0-\bar{K}^0 Mixing and New Physics Effects on CP
  Violation in D^{\pm} and D^{\pm}_s Decays

abstract:
  Flavor symmetry and symmetry breaking, K^0-\bar{K}^0 mixing and possible
effects of new physics on CP violation in weak decay modes D^{\pm} \to K_{S,L}
+ X^{\pm}, (K_{S,L} + \pi^0)_{K^*} + X^{\pm} (for X =\pi, \rho, a_1) and
D^{\pm}_s \to K_{S,L} + X^{\pm}_s, (K_{S,L} +\pi^0)_{K^*} + X^{\pm}_s (for X_s
= K, K^*) are analyzed. Relations between D^{\pm} and D^{\pm}_s decay branching
ratios are obtained from the d \Leftrightarrow s subgroup of SU(3) and dominant
symmetry-breaking mechanisms are investigated. A CP asymmetry of magnitude
3.3\times 10^{-3} is shown to result in the standard model from K^0-\bar{K}^0
mixing in the final-state. New physics affecting the doubly Cabibbo-suppressed
channels might either cancel this asymmetry or enhance it up to the percent
level. A comparison between the CP asymmetries in D^{\pm}_{(s)} \to K_{S}
X^{\pm}_{(s)} and D^{\pm}_{(s)} \to K_L X^{\pm}_{(s)} can pin down effects of
new physics.


title:
Expansion Techniques in Massive Quark Production: Results and
  Applications

abstract:
  Recent progress in the calculation of multi-loop, multi-scale diagrams is
reviewed. Expansion techniques combined with new developments in Computer
algebra allow to evaluate the R ratio for massive quarks up to order
$\alpha_s^2$ and, partly, even $\alpha_s^3$. Similar techniques can be applied
to Higgs- or Z-boson decays and mixed QCD and electroweak interactions.


title: NLO BFKL Equation, Running Coupling and Renormalization Scales

abstract:
  I examine the solution of the BFKL equation with NLO corrections relevant for
deep inelastic scattering. Particular emphasis is placed on the part played by
the running of the coupling. It is shown that the solution factorizes into a
part describing the evolution in Q^2, and a constant part describing the input
distribution. The latter is infrared dominated, being described by a coupling
which grows as x decreases, and thus being contaminated by infrared
renormalons. Hence, for this part we agree with previous assertions that
predictive power breaks down for small enough x at any Q^2. However, the former
is ultraviolet dominated, being described by a coupling which falls like
1/(\ln(Q^2/\Lambda^2) + A(\bar\alpha_s(Q^2)\ln(1/x))^1/2)with decreasing x, and
thus is perturbatively calculable at all x. Therefore, although the BFKL
equation is unable to predict the input for a structure function for small x,
it is able to predict its evolution in Q^2, as we would expect from the
factorization theory. The evolution at small x has no true powerlike behaviour
due to the fall of the coupling, but does have significant differences from
that predicted from a standard NLO in alpha_s treatment. Application of the
resummed splitting functions with the appropriate coupling constant to an
analysis of data, i.e. a global fit, is very successful.


title: Measuring the number of hadronic jets

abstract:
  A quantitative description of the qualitative feature of multi-hadron final
states known as the "number of jets" is given by a sequence of infrared finite
shape observables (jet discriminators) that: take continuous values between 0
and 1; are stable-unlike clustering algorithms-against small variations of the
input (data errors, Sudakov effects etc.); have a form of multiparticle
correlators that is natural in the context of quantum field theory and hence
are better suited for a systematic study of theoretical uncertainties
(logarithmic and power corrections).


title: New Insight into the Photoproduction of D-star meson in QCD

abstract:
  In the framework of the model motivated by perturbative calculations in the
fourth $O(\alpha^3_s\alpha)$-order, the estimates for the $\gamma p$
cross-section of the $D^*$-meson production in the ZEUS experiment are
performed. We factorize the hadronization of $(c\bar q)$-state hardly produced
in perturbative QCD, which allows us to take into account the higher twist
terms in the powers of $1/p_T$ at $p_T\sim m_c$ and to correctly reproduce the
c-quark fragmentation dominant at high $p_T\gg m_c$ to the given order of
$\alpha_s$. We find a good agreement with the experimental data on the
photoproduction, if the color-octet $(c\bar q)$-state is taken into account,
which yields $<O_{(8)} > \approx 0.33-0.49 GeV^3$.


title: Hunting the Vector Hybrid

abstract:
  The current state of analysis of e+e- annihilation below 2.0 GeV and of the
vector component of tau decay is reviewed. The evidence for and against the
presence of hybrid vectors is discussed. It is concluded that the data strongly
favour their inclusion, and the consequences of this are outlined.


title: High P_T Leptons and W Production at HERA

abstract:
  Details are given of the observation by H1 of events containing high P_T
leptons in addition to large missing P_T. A closely related ZEUS analysis,
including a preliminary measurement of the W production cross section, is
discussed and the two experiments are compared. Some possible non-Standard
Model sources for the events are considered.


title:
Topological inflation induced by a non-minimally coupled massive scalar
  field

abstract:
  We reanalyze cosmology of a non-minimally coupled massive scalar field which
was originally discussed by Futamase and Maeda in the context of chaotic
inflation scenario. We find a new type of inflationary solution where inflation
occurs inside a domain wall. This new solution relaxes constraints on the
coupling constant for successful inflation.


title: Leptogenesis with virtual Majorana neutrinos

abstract:
  We present a mechanism of leptogenesis based on the out-of-equilibrium decay
of a scalar particle into heavy virtual Majorana neutrinos. This scheme
presents many conceptual advantages over the conventional scenario of Fukugita
and Yanagida. In particular, the standard techniques of quantum field theory
can be used to compute the lepton asymmetry, without resorting to the
phenomenological approximations usually made to describe unstable particles.
This simplification allows us to address in a well-defined framework some
issues raised in the recent literature. We also show, in a toy model, that a
successful leptogenesis scenario is possible and requires a rather light scalar
particle, $10^6 GeV < m < 10^{13} GeV$. A natural embedding of this scheme in a
gauged unified theory encompassing the Majorana fermions seems however
difficult.


title: Diquarks as effective particles in hard exclusive scattering

abstract:
  In the context of hard hadronic reactions diquarks are a useful
phenomenological device to model non-perturbative effects still observable in
the kinematic range accessible by present-day experiments. In the following we
present diquark-model predictions for $\gamma\gamma \to p \bar{p}$ and $\Lambda
\bar{\Lambda}$. We also sketch how the (pure quark) hard-scattering formalism
for exclusive reactions involving baryons can be reformulated in terms of
quarks and diquarks. As an application of these considerations we analyze the
magnetic proton form factor with regard to its quark-diquark content.


title: The spin dependence of high energy proton scattering

abstract:
  Motivated by the need for an absolute polarimeter to determine the beam
polarization for the forthcoming RHIC spin program, we study the spin
dependence of the proton-proton elastic scattering amplitudes at high energy
and small momentum transfer.We examine experimental evidence for the existence
of an asymptotic part of the helicity-flip amplitude phi_5 which is not
negligible relative to the largely imaginary average non-flip amplitude phi_+.
We discuss theoretical estimates of r_5, essentially the ratio of phi_5 to
phi_+, based upon extrapolation of low and medium energy Regge phenomenological
results to high energies, models based on a hybrid of perturbative QCD and
non-relativistic quark models, and models based on eikonalization techniques.
We also apply the model-independent methods of analyticity and unitarity.The
preponderence of evidence at available energy indicates that r_5 is small,
probably less than 10%. The best available experimental limit comes from
Fermilab E704:those data indicate that |r_5|<15%. These bounds are important
because rigorous methods allow much larger values. In contradiction to a
widely-held prejudice that r_5 decreases with energy, general principles allow
it to grow as fast as ln(s) asymptotically, and some models show an even faster
growth in the RHIC range. One needs a more precise measurement of r_5 or to
bound it to be smaller than 5% in order to use the classical Coulomb-nuclear
interference technique for RHIC polarimetry. As part of this study, we
demonstrate the surprising result that proton-proton elastic scattering is
self-analysing, in the sense that all the helicity amplitudes can, in
principle, be determined experimentally at small momentum transfer without a
knowledge of the magnitude of the beam and target polarization.


title:
Observed Asymmetry in $\bar{p}p \to \pi^+ K^- K^0 / \pi^- K^+ \bar{K}^0$
  and Relation to Reciprocity

abstract:
  The charge-asymmetry observed in a recent CPLEAR experiment was interpreted
by the authors as a direct observation of T-noninvariance. While this is the
simplest and most natural inference, and the observed effect agrees in sign and
magnitude with theoretical expectation, adherents of T-invariance may argue
that other interpretations are also possible. If K^0 and \bar{K}^0 are produced
equally in \bar{p} p annihilation, and T-invariance is assumed to hold, the
asymmetry observed in CPLEAR must be attributed to TCP-noninvariance of kaon
beta-decays. If that were the case, the charge-asymmetry in K_S^0 \to \pi l\nu
decays should be three times larger than the one observed for K_L^0 decays.


title: The dependence of the emission size on the hadron mass

abstract:
  The size of the emission volume of pions and kaons, r_{\pi\pi} and r_{KK},
were measured in the hadronic Z^0 decays through the two-pion and two-kaon
Bose-Einstein correlations near threshold. Recently the emitter size of the two
identical baryons, \Lambda \Lambda (\bar \Lambda \bar \Lambda), was evaluated
from the dependence of the fraction of the spin S=1 state on the energy near
threshold where it is affected by the Pauli exclusion principle. Here we show
that the r dependence on the particle masses, namely the hierarchy r_{\pi\pi} >
r_{KK} > r_{\Lambda \Lambda} observed in the Z^0 hadronic decays, is well
described in terms of the Heisenberg uncertainty principle. A good description
can also be obtained via the virial theorem when applied to a general QCD
potential. Other available approaches are also discussed.


title:
Long-range two-body final-state interactions and direct CP asymmetry in
  {B}^{+}\to{\pi}^{+} {K}^{0} decay

abstract:
  We present a calculation of the direct CP asymmetry, $A_{CP}^{dir}$, for the
process $B^+ \to \pi^+ K^0$ including the effects of long-range inelastic
final-state interactions (FSI). We admit three channels in our calculation:
$B^+ \to (\pi^+ K^0), (\eta K^+)$, and $(D_s^+ \bar{D}^0)$. The strong
scattering is described in terms of Pomeron and Regge exchanges. We find that
the direct CP asymmetry is enhanced by a factor of $\sim 3$ as a result of FSI,
but remains well short of the claims of (10 - 20)% in recent literature. A
critical assessment of papers claiming large CP asymmetries is also presented.


title: CP Violation in Decays Z --> 4 Jets

abstract:
  We analyse CP-violating effects in Z \to 4 jet decays, assuming the presence
of CP-violating effective $Z b \bar{b} G$ and $Z b \bar{b} G G$ couplings. We
discuss the influence of these couplings on the decay width. Furthermore, we
propose various strategies of a direct search for such CP-violating couplings
by using different CP-odd observables. The present data of LEP 1 should give
significant information on the couplings.


title:
Bounds On Anomalous Magnetic And Electric Moments Of Tau Lepton From LEP
  And Lepton Flavor Violation

abstract:
  The most stringent bounds on the anomalous magnetic and electric dipole
moments of the tau lepton was derived by Escribano and Mass\'{o}[6] from the Z
width at LEP in an effective lagrangian approach to the new physics. In this
paper we point out that the higher dimensional operators introduced by
Escribano and Mass\'{o} not only modify the neutral currents of the tau lepton
to Z gauge boson and the photon, but also induce lepton flavor violation (LFV).
The size of the LFV effect depends crucially on the dynamics of the lepton mass
generation. Assuming the lepton mass matrices in the form of an Fritzsch
ansatz, we point out that the experimental limit on $\mu \to e \gamma$ will
push the anomalous magnetic and electric dipole moments of the tau lepton down
to $10^{-11}$ and $10^{-25} e cm$ respectively.


title:
A Gauge-Mediation Model of Dynamical SUSY Breaking with a Wide Range of
  the Gravitino Mass

abstract:
  We provide a gauge-mediation model of dynamical supersymmetry breaking where
the gravitino mass takes a value in a wide range from 0.1 eV to 10 GeV. The
lower mass region of order 100 keV or less deserves experimental and
cosmological interests. The vacuum of our model is a true one without runaway
instability, which may be desirable in a cosmological evolution of the
universe.


title: Neutrinos, their Partners and Unification

abstract:
  Efforts to unify group-theoretically the standard-model gauge interactions
with the generation structure of fermions and their mirror partners should be
accompanied with the unification of the corresponding gauge couplings. In this
paper the possibility of such a unification is studied and conclusions on
possible symmetry-breaking channels and scales, as well as on the fermion
content of the theory, are drawn. The breaking of some of the symmetries allows
various Majorana masses for neutrinos and their mirror partners, so these are
studied next. Implications to neutrino mixings and mass hierarchies in
connection with recent experimental results, as well as to electroweak
precision tests, are then discussed.


title:
Comment on ``Next-to-next-to-leading order vacuum polarization function
  of heavy quark near threshold and sum rules for $b \bar b$ system'' and
  ``Next-to-next-to-leading order relation between $R(e^+e^-\to b\bar b)$ and
  $\Gamma_{\rm sl}(b\to cl\nu_l)$ and precise determination of $|V_{cb}|$''

abstract:
  The most recent recalculation of the two-loop correction to the static
quark-antiquark potential gave the numerical value different from the
previously known one. We comment on the effect this change produces on the
numerical estimates of the bottom quark pole mass $m_b$, the strong coupling
constant $\al_s$ and the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$
obtained in our papers [1,2].


title:
Inclusive J/psi and psi(2S) Production from B Decay in p p-bar
  Collisions

abstract:
  Using information on B-meson fragmentation functions from CERN LEP 1 and
adopting the nonrelativistic QCD factorization formalism proposed by Bodwin,
Braaten, and Lepage, we predict the transverse-momentum distribution of J/psi
mesons originating from the inclusive decays of b hadrons produced in p p-bar
collisions at the Fermilab Tevatron. We determine the relevant colour-octet
charmonium matrix elements from fits to CDF data on prompt charmonium
hadroproduction and to CLEO data on charmonium production from B-meson decay.
Our predictions are found to agree well with recent CDF and D0 data.


title: Polarization in semileptonic B decays

abstract:
  The paper gives the polarization of the tau lepton in the semileptonic B
decays with respect to the direction of the virtual W boson. The result is
given including the nonperturbative HQET corrections.The perturbative QCD
corrections are probably negligible as suggested by the existing results for
the longitudinal polarization of the charged lepton (Jezabek and Urban, 1998).


title: On Exotic Solutions of the Atmospheric Neutrino Problem

abstract:
  The measurements of the fluxes of atmospheric neutrinos give evidence for the
disappearance of muon neutrinos. The determination of the dependence of the
disappearance probability on the neutrino energy and trajectory allows in
principle to establish unambiguosly the existence of neutrino oscillations.
Alternative mechanisms for the disappearance of the neutrinos have been
proposed, but do not provide a viable description of the data, if one includes
both events where the neutrinos interact in the detector and $\nu$-induced
upward going muons. The proposed mechanisms differ in the energy dependence of
the disappearance probability and the upward going muon data that are produced
by high energy neutrinos give a crucial constraint.


title:
Constraints on the mSUGRA parameter space from electroweak precision
  data

abstract:
  We place constraints on the parameter space of the minimal supergravity
(SUGRA) inspired supersymmetric (SUSY) extension of the standard model (SM),
i.e. the mSUGRA model, by studying the loop-level contributions of
supersymmetric particles to electroweak precision observables. In general the
Higgs and superpartner particles of SUSY models contribute to electroweak
observables through universal propagator corrections as well as
process-specific vertex and box diagrams. However, because the mass of the
lightest chargino is contrained to be greater than 91 GeV, we find that the
process-dependent contributions to four-fermion amplitudes are negligibly
small. Hence, the full analysis may be reduced to an analysis of the propagator
corrections, and in some regions of parameter space the constraints from the (b
---> s gamma) process are quite important. The propagator corrections are
dominated by the contributions of the scalar fermions, and we summarize the
results in the Peskin-Takeuchi S-T plane and the contributions to the W-boson
mass. We then present the results in the mSUGRA m_0 -- m_{1/2} plane and find
that our analysis of the propagator corrections provides constraints in the
small-m_0 -- small-m_{1/2} region, precisely the region of interest for
collider phenomenology. In some regions of parameter space, especially for mu <
0 and large tan(beta), the constrained region is enlarged considerably by
including the process (b ---> s gamma).


title: QCD at High Energies

abstract:
  This talk summarizes recent QCD results from HERA, the Tevatron Collider and
Tevatron fixed target experiments.


title: Dark matter from Affleck-Dine baryogenesis

abstract:
  Fragmentation of the Affleck-Dine condensate into Q-balls could fill the
Universe with dark matter either in the form of stable baryonic balls, or LSP
produced from the decay of unstable Q-balls. The dark matter and the ordinary
matter in the Universe may share the same origin.


title: Baryon masses in large Nc chiral perturbation theory

abstract:
  We analyse the baryon mass spectrum in a framework which combines the 1/Nc
expansion with chiral perturbation theory. Meson loop contributions involving
the full SU(3) octet of pseudoscalar Goldstone bosons are evaluated, and the
influence of explicit chiral and flavor symmetry breaking by non-zero and
unequal quark masses is investigated. We also discuss sigma terms and the
strangeness contribution to the nucleon mass.


title: Atmospheric Neutrinos and Neutrino Oscillations

abstract:
  After some generalities on neutrino oscillations and on neutrinos, the recent
experimental results presented by Soudan 2, MACRO and SuperKamiokande at the
Neutrino'98 conference are summarized and discussed.


title:
Irreversibility, steady state, and non-equilibrium physics in
  relativistic heavy ion collisions

abstract:
  Heavy ion collisions at ultrarelativistic energies offer the opportunity to
study the irreversibility of multiparticle processes. Together with the
many-body decays of resonances, the multiparticle processes cause the system to
evolve according to Prigogine's steady states rather than towards statistical
equilibrium. These results are general and can be easily checked by any
microscopic string-, transport-, or cascade model for heavy ion collisions. The
absence of pure equilibrium states sheds light on the difficulties of thermal
models in describing the yields and spectra of hadrons, especially mesons, in
heavy ion collisions at bombarding energies above 10 GeV/nucleon.


title:
Non-thermal Production of Neutralino Cold Dark Matter from Cosmic String
  Decays

abstract:
  We propose a mechanism of nonthermal production of a neutralino cold dark
matter particle, $\chi$, from the decay of cosmic strings which form from the
spontaneous breaking of a U(1) gauge symmetry, such as $U_{B-L}(1)$, in an
extension of the minimal supersymmetric standard model (MSSM). By explicit
calculation, we point out that with a symmetry breaking scale $\eta$ of around
$10^8$ GeV, the decay of cosmic strings can give rise to $\Omega_\chi \simeq
1$. This gives a new constraint on supersymmetric models. For example, the dark
matter produced from strings will overclose the universe if $\eta$ is near the
electroweak symmetry breaking scale. To be consistent with $\Omega_\chi \leq
1$, the mass of the new U(1) gauge boson must be much larger than the Fermi
scale which makes it unobservable in upcoming accelerator experiments. In a
supersymmetric model with an extra $U_{B-L}(1)$ symmetry, the requirement of
$\Omega_\chi \leq 1$ puts an upper bound on the neutrino mass of about $30 eV$
provided neutrino masses are generated by the see-saw mechanism.


title: Radiatively Induced Lorentz and CPT Violation in Electrodynamics

abstract:
  In a nonperturbative formulation, radiative corrections arising from Lorentz
and CPT violation in the fermion sector induce a definite and nonzero
Chern-Simons addition to the electromagnetic action. If instead a perturbative
formulation is used, an infinite class of theories characterized by the value
of the Chern-Simons coefficient emerges at the quantum level.


title: Standard Model Large-E_T Processes and Searches for New Physics at HERA

abstract:
  Existing and missing calculations of standard model processes producing large
transverse energy in electron-proton interactions at HERA are reviewed. The
adequacy of the existing standard model Monte Carlo programs for generic
searches of exotic processes is analyzed.


title:
Power corrections in the longitudinal and transverse structure functions
  of proton and deuteron

abstract:
  Power corrections to the Q**2 behaviour of the low-order moments of both the
longitudinal and transverse structure functions of proton and deuteron have
been investigated using available phenomenological fits of existing data in the
Q**2 range between 1 and 20 (GeV/c)**2. The Natchmann definition of the moments
has been adopted for disentangling properly target-mass and dynamical
higher-twist effects in the data. The leading twist has been treated at
next-to-leading order in the strong coupling constant and the effects of higher
orders of the perturbative series have been estimated using a
renormalon-inspired model. The contributions of (target-dependent) multiparton
correlations to both 1/Q**2 and 1/Q**4 power terms have been determined in the
transverse channel, while the longitudinal one appears to be consistent with a
pure infrared renormalon picture in the whole Q**2-range between 1 and 20
(GeV/c)**2. Finally, the extracted twist-2 contribution in the deuteron turns
out to be compatible with the hypothesis of an enhanced d-quark parton
distribution at large x.


title: Bhabha scattering at LEP1. Calorimeter event selection

abstract:
  Analitical calculations have been used to describe the calorimeter event
selection in small-angle electron-positron scattering at LEP1. The first-order
QED correction to the Born cross-section has been derived with leading log and
the next-to-leading log approximations. The second- and the third-order
corrections were computed with leading accuracy. The present analytical results
are illustated by Tabeles and compared with the corresponding results obtained
with the Monte Carlo generator BHLUMI.


title: Recent Progress in Baryogenesis

abstract:
  We provide an up to date account of progress in understanding the origin of
the observed baryon asymmetry of the universe. While our primary goal is to be
current, we have attempted to give a pedagogical introduction to the primary
areas of research in this field, giving a detailed description of the different
scenarios. The very recent developments in GUT baryogenesis, leptogenesis,
electroweak baryogenesis and the Affleck-Dine mechanism are presented. In
particular, we focus on specific particle physics implementations, mostly in
the context of supersymmetry, which lead to specific testable predictions.


title:
The limits on CP-odd four-fermion operators containing strange quark
  field

abstract:
  The bounds on the neutron electric dipole moment and T-odd nucleon-nucleon
interaction are used to extract the limits on the effective CP-odd four-fermion
operators containing strange quark field. This completes the study of the
dim=5,6 CP-odd operators built from the light-quark fields. The limits are very
strong and comparable to those obtained previously for operators containing up
and down flavors. We also analyze the shift of the axionic vacuum,
$\theta_{eff}$, induced by four-fermion operators in the presence of PQ
mechanism and conclude that this gives subleading contributions to CP-odd
observables as compared with the direct ones.


title:
Scalar-Scalar Ladder Model in the Unequal-Mass Case. III - Numerical
  Studies of the P-Wave Case -

abstract:
  The eigenvalue problem for the p-wave bound states formed by two unequal-mass
scalar particles through the massive scalar particle exchange is analyzed
numerically in the framework of the Bethe-Salpeter ladder model.
  As in the s-wave case, the eigenvalues of the coupling constant are found to
become complex for some mass configurations in some range of the bound state
mass. The Bethe-Salpeter amplitudes of the low-lying bound states are also
investigated.


title:
How Well Can We Predict the Mass of the Higgs Boson of the Minimal
  Supersymmetric Model?

abstract:
  The upper bound on the mass of the light CP-even Higgs boson of the minimal
supersymmetric model (MSSM) depends on the supersymmetric particle spectrum via
radiative loop effects. At present, complete one-loop results and partial
two-loop results are known. Some simple analytic approximations have been
obtained which are quite accurate over a large portion of the MSSM parameter
space. Based on these results, I examine how accurately one can predict the
upper bound on the mass of the lightest MSSM Higgs boson.


title:
CP Violation and Beauty Decays -- A Case Study of High Impact, High
  Sensitivity and Even High Precision Physics

abstract:
  The narrative of these lectures contains three main threads: (i) CP violation
despite having so far been observed only in the decays of neutral kaons has
been recognized as a phenomenon of truly fundamental importance. The KM ansatz
constitutes the minimal implementation of CP violation: without requiring
unknown degrees of freedom it can reproduce the known CP phenomenology in a
nontrivial way. (ii) The physics of beauty hadrons -- in particular their weak
decays -- opens a novel window onto fundamental dynamics: they usher in a new
quark family (presumably the last one); they allow us to determine fundamental
quantities of the Standard Model like the $b$ quark mass and the CKM parameters
$V(cb)$, $V(ub)$, $V(ts)$ and $V(td)$; they exhibit speedy or even rapid $B^0 -
\bar B^0$J oscillations. (iii) Heavy Quark Expansions allow us to treat $B$
decays with an accuracy that would not have been thought possible a mere decade
ago. These three threads are joined together in the following manner: (a) Huge
CP asymmetries are {\em pre}dicted in $B$ decays, which represents a decisive
test of the KM paradigm for CP violation. (b) Some of these predictions are
made with high {\em parametric} reliability, which (c) can be translated into
{\em numerical} precision through the judicious employment of novel theoretical
technologies. (d) Beauty decays thus provide us with a rich and promising field
to search for New Physics and even study some of its salient features. At the
end of it there might quite possibly be a New Paradigm for High Energy Physics.
There will be some other threads woven into this tapistry: electric dipole
moments, and CP violation in other strange and in charm decays.


title:
Way to Discriminate between Mesons and Glueballs for $I=0,
  J^{PC}=even^{++}$ Unflavored Hadrons

abstract:
  Based on the general analysis of branching ratio of two pseudoscalar meson
channels, discriminants between mesons and glueballs for $I=0,
J^{PC}=even^{++}$ unflavored hadrons with mass between 1.2 GeV and 2.9 GeV are
suggested. Known $I=0, J^{PC}=2^{++}, f_2(1525)$ particle is discriminated as a
typical meson. The way to discriminate new $I=0, J^{PC}=even^{++}$ unflavored
hadrons is discussed.


title: Single-photon events in e^+ e^- collisions

abstract:
  We provide a detailed investigation of single-photon production processes in
$e^+e^-$ collisions with missing momenta carried by neutrinos or neutralinos.
The transition amplitudes for both processes can be organized into a generic
simplified, factorized form; each neutral V$\pm$A vector current of missing
energy carriers is factorized out and all the characteristics of the reaction
is solely included in the electron vector current. Firstly, we apply the
generic form to give a unified description of a single-photon production with a
Dirac-type or Majorana-type neutrino-pair and to confirm their identical
characteristics as suggested by the so-called Practical Dirac-Majorana
Confusion Theorem. Secondly, we show that the generic amplitude form is
maintained with the anomalous P- and C-invariant WW$\gamma$ couplings in the
neutrino-associated process and it enables us to easily understand large
contributions of the anomalous WW$\gamma$ couplings at higher energies and, in
particular, at the points away from the Z-resonance peak. Finally, the
neutralino-associated process, which receives modifications in both the
left-handed and right-handed electron currents due to the exchanges of the
left-handed and right-handed selectrons, can be differentiated from the
neutrino-associated ones through the left-right asymmetries and/or the circular
polarization of the outgoing photon.


title:
Top-Charm Associated Production at High Energy e^+e^- Colliders in
  Standard Model

abstract:
  The flavor changing neutral current tcV (V=\gamma,Z) couplings in the
production vertex for the process $e^+e^-\to t\bar c$ or $\bar t c$ in the
standard model are investigated. The precise calculations keeping all quark
masses non-zero are carried out. The total production cross section is found to
be $1.84 \times 10^{-9}$ fb at $\sqrt s =200 GeV$ and $0.572 \times 10^{-9}$ fb
at $\sqrt s =500 GeV$ respectively. The result is much smaller than that given
in ref. \cite{clwy} by a factor of $10^{-5}$.


title: Bound states in monopoles: sources for UHECR ?

abstract:
  Bound states in monopoles are studied through a simplified, Witten-like
model. As the overall structure is determined in full details, it is shown in
particular that only those states having a vanishing angular momentum are
allowed; for those, the energy spectrum is derived numerically and an
approximation is set up that allows an easy description in terms of
wavefunctions, usefull for further applications. The monopoles are then
proposed as candidates of ultra high energy cosmic rays, an hypothesis that
should soon be testable through the Pierre Auger Observatory.


title: Nucleus-nucleus collisions in the Dynamical String Model

abstract:
  In this paper the Dynamical String Model is applied to the numerical
simulation of the ultrarelativistic heavy-ion collision S(200 GeV/n)+S. The
results are in qualitative agreement with experimental data.


title:
Long vs. short distance dispersive two-photon K_L \to \mu^+ \mu^-
  amplitude

abstract:
  We report on the calculation of the two-loop electroweak, two-photon mediated
short-distance dispersive K_L \to \mu^+\mu^- decay amplitude. QCD corrections
change the sign of this contribution and reduce it by an order of magnitude.
The resulting amplitude enables us to provide a constraint on the otherwise
uncertain long-distance dispersive amplitude.


title: Sensitivity of Low-Energy Parity-Violation To New Physics

abstract:
  I review the new physics sensitivity of low-energy parity-violating (PV)
observables. I concentrate on signatures of new tree-level physics in atomic PV
with a single isotope, ratios of atomic PV observables, and PV electron
scattering. In addition to comparing the new physics sensitivities of these
observables with those of high-energy colliders, I also discuss the theoretical
issues involved in the extraction of new physics limits from low-energy PV
observables.


title: The Goldberger-Treiman Discrepancy in SU(3)

abstract:
  The Goldberger-Treiman discrepancy in SU(3) is analyzed in the framework of
heavy baryon chiral perturbation theory (HBChPT). It is shown that the
discrepancy at leading order is entirely given by counterterms from the order
p^3 Lagrangian, and that the first subleading corrections are suppressed by two
powers in the HBChPT expansion. These subleading corrections include meson-loop
contributions as well as counterterms from the order p^5 Lagrangian. Some
one-loop contributions are calculated and found to be small. Using the three
discrepancies (pi-N-N, K-N-Lambda and K-N-Sigma) which can be extracted from
existing experimental data, we find that the HBChPT calculation favors the
smaller g(pi-N-N) values obtained in recent partial wave analyses.


title: $J/\psi$ Photoproduction and the Gluon Structure of the Nucleon

abstract:
  Using short distance QCD methods based on the operator product expansion, we
calculate the $J/\psi$ photoproduction cross section in terms of the gluon
distribution function of the nucleon. Comparing the result with data, we show
that experimental behaviour of the cross section correctly reflects the
$x$-dependence of the gluon distribution obtained from deep inelastic
scattering.


title: Odderon and photon exchange in electroproduction of pseudoscalar mesons

abstract:
  We investigate the reaction $e p \to e PS X$ where PS denotes a pseudoscalar
meson $\pi^0, \eta, \eta'$, or $\eta_c$ and X either a proton or resonance or
continuum states into which the proton can go by diffractive excitation. At
high energies photon and odderon exchange contribute to the reaction. The
photon exchange contribution is evaluated exactly using data for the total
virtual photon-proton absorption cross section. The odderon exchange
contribution is calculated in nonperturbative QCD, using functional integral
techniques and the model of the stochastic vacuum. For the proton we assume a
quark-diquark structure as suggested by the small odderon amplitude in $pp$ and
$p \bar{p}$ forward scattering. We show that odderon exchange leads to a much
larger inelastic than elastic PS production cross section. Observation of our
reaction at HERA would establish the soft odderon as an exchange object on an
equal footing with the soft pomeron and would give us valuable insight into
both the nucleon structure and the mechanism of high energy diffractive
scattering.


title: NJL model on the light cone and pion structure function

abstract:
  The NJL model is formulated on the light cone. Using the 1/N expansion to
solve the fermionic constraint, an effective 4-fermi lagrangian is derived.
Pionic properties are investigated using this lagrangian, and the formal
equivalence to the equal-time formulation is demonstrated. Two regularization
schemes in terms of light-cone variables are discussed: An extension of the
'invariant mass cut-off scheme', and a transverse momentum cut-off scheme. It
is shown that the first one is equivalent to the covariant 3-momentum cut-off
(dispersion cut-off) scheme in the equal-time formulation. As an application
the structure function of the pion is studied in both regularization schemes.


title:
Heavy-to-Light Form Factors in the Final Hadron Large Energy Limit:
  Covariant Quark Model Approach

abstract:
  We prove the full covariance of the heavy-to-light weak current matrix
elements based on the Bakamjian-Thomas construction of relativistic quark
models, in the heavy mass limit for the parent hadron and the large energy
limit for the daughter one. Moreover, this quark model representation of the
heavy-to-light form factors fulfills the general relations that were recently
argued to hold in the corresponding limit of QCD, namely that there are only
three independent form factors describing the B -> pi (rho) matrix elements, as
well as the factorized scaling law sqrt(M)z(E) of the form factors with respect
to the heavy mass M and large energy E. These results constitute another good
property of the quark models \`a la Bakamjian-Thomas, which were previously
shown to exhibit covariance and Isgur-Wise scaling in the heavy-to-heavy case.


title:
Correlation between UV and IR cutoffs in quantum field theory and large
  extra dimensions

abstract:
  A recently conjectured relashionship between UV and IR cutoffs in an
effective field theory without quantum gravity is generalized in the presence
of large extra dimensions. Estimates for the corrections to the usual
calculation of observables within quantum field theory are used to put very
stringent limits, in some cases, on the characteristic scale of the additional
compactified dimensions. Implications for the cosmological constant problem are
also discussed.


title: Exotic $\rho^\pm\rho^0$ state photoproduction

abstract:
  It is shown that the list of unusual mesons planned for a careful study in
photoproduction can be extended by the exotic states $X^\pm(1600)$ with $I^G(J
^{PC})=2^+(2^{++})$ which should be looked for in the $\rho^\pm\rho^0$ decay
channels in the reactions $\gamma N\to\rho^\pm\rho^0N$ and $\gamma N\to\rho^\pm
\rho^0\Delta$. The full classification of the $\rho^\pm\rho^0$ states by their
quantum numbers is presented. A simple model for the spin structure of the $
\gamma p\to f_2(1270)p$, $\gamma p\to a^0_2(1320)p$, and $\gamma N\to X^\pm (N,
\Delta)$ reaction amplitudes is formulated and the tentative estimates of the
corresponding cross sections at the incident photon energy $E_\gamma\approx 6$
GeV are obtained: $\sigma(\gamma p\to f_2(1270)p)\approx0.12$ $\mu$b, $
\sigma(\gamma p\to a^0_2(1320)p)\approx0.25$ $\mu$b, $\sigma(\gamma N\to X^\pm
N\to\rho^\pm\rho^0N)\approx0.018$ $\mu$b, and $\sigma(\gamma p\to X^-\Delta^{++
}\to\rho^-\rho^0\Delta^{++})\approx0.031$ $\mu$b. The problem of the $X^\pm$
signal extraction from the natural background due to the other $\pi^\pm\pi^0
\pi^+\pi^-$ production channels is discussed. In particular the estimates are
presented for the $\gamma p\to h_1(1170)\pi^+n$, $\gamma p\to\rho'^{+}n\to
\pi^+\pi^0\pi^+\pi^-n$, and $\gamma p\to\omega\rho^0p$ reaction cross sections.
Our main conclusion is that the search for the exotic $X^\pm(2^+(2^{++}))$
states is quite feasible at JEFLAB facility. The expected yield of the $\gamma
N\to X^\pm N\to\rho^\pm\rho^0N$ events in a 30-day run at the 100% detection
efficiency approximates $2.8\times10^6$ events.


title: Chiral Effective Theories

abstract:
  These are the proceedings of the workshop on ``Chiral Effective Theories''
held at the Physikzentrum Bad Honnef of the Deutsche Physikalische
Gesellschaft, Bad Honnef, Germany from November 30 to December 4, 1998. The
workshop concentrated on Chiral Perturbation Theory in its various settings and
its relations with lattice QCD and dispersion theory. Included are a short
contribution per talk and a listing of some review papers on the subject.


title: Mass dependence of the HBT radii observed in e+e- annihilation

abstract:
  It is shown that the recently established strong mass- dependence of the
radii of the hadron sources, as observed in HBT analyses of the $e^+e^-$
annihilation, can be explained by assuming a generalized inside-outside
cascade, i.e. that (i) the four-momenta and the space-time position
four-vectors of the produced particles are approximately proportional to each
other and (ii) the "freeze-out"times are distributed along the hyperbola $t^2 -
z^2 = \tau_0^2$.


title: New Families of Scaling Multiparticle Distributions

abstract:
  Recently equations for the generating functional in the perturbative quantum
chromodynamics (QCD) have been extended by including the non-perturbative
dissipation in QCD jets. The resulting equations have been solved rigorously
and new family of scaling solutions, the so-called delta - scaling,
generalizing the well-known Kubo-Nielsen-Olesen scaling law for hadron
multiplicity distributions have been found. The relevance of delta - scaling is
discussed in the Landau - Ginzburg theory of phase transitions. Preliminary
application of these ideas to the p{\bar p} data of the UA5 Collaboration is
presented.


title: Baryon Chiral Perturbation Theory in Manifestly Lorentz Invariant Form

abstract:
  We show that in the presence of massive particles such as nucleons, the
standard low energy expansion in powers of meson momenta and light quark masses
in general only converges in part of the low energy region. The expansion of
the scalar form factor $\sigma(t)$, for instance, breaks down in the vicinity
of $t=4M_\pi^2$. In the language of heavy baryon chiral perturbation theory,
the proper behaviour in the threshold region only results if the multiple
internal line insertions generated by relativistic kinematics are summed up to
all orders. We propose a method that yields a coherent representation
throughout the low energy region while keeping Lorentz and chiral invariance
explicit at all stages. The method is illustrated with a calculation of the
nucleon mass and of the scalar form factor to order $p^4$.


title: The Role of Nucleons in Electromagnetic Emission Rates

abstract:
  Electromagnetic emission rates from a thermalized hadronic gas are important
for the interpretation of dilepton signals from heavy-ion collisions. Although
there is a consensus in the literature about rates for a pure meson gas,
qualitative differences appear with a finite baryon density. We show this to be
essentially due to the way in which the pi-N background is treated in regards
to the nucleon resonances. Using a background constrained by unitarity and
broken chiral symmetry, it is emphasized that the thermalized hadronic gas can
be considered dilute.


title:
Hadronic effects in (g-2)_mu and alpha_QED (M_Z): Status and
  perspectives

abstract:
  I review recent evaluations of the hadronic contributions to the muon
anomalous magnetic moment (g-2)_mu and to the effective fine structure constant
alpha (M_Z). A new estimate for the hadronic shift delta_alpha hadronic =
0.027782 +/- 0.000254 is presented which implies 1/alpha (M_Z) = 128.913 +/-
0.035. It is based on a recent perturbative calculation of the Adler function
which includes mass effects up to three-loops in a MOM scheme and requires
little ad hoc assumptions. I then discuss perspectives for possible
improvements in estimations of g-2 which we expect from the Phi--factory DAPHNE
at Frascati.


title: On Forward J/\psi Production at Fermilab Tevatron

abstract:
  The D0 Collaboration has recently reported the measurement of J/\psi
production at low angle. We show here that the inclusion of color octet
contributions in any framework is able to reproduce this data.


title: Neutrino Mixing, CP/T Violation and Textures in Four-Neutrino Models

abstract:
  We examine the prospects for determining the neutrino mixing matrix and for
observing CP and T violation in neutrino oscillations in four-neutrino models.
We focus on a general class of four-neutrino models with two pairs of nearly
degenerate mass eigenstates separated by approximately 1 eV, which can describe
the solar, atmospheric and LSND neutrino data. We present a general
parametrization of these models and discuss in detail the determination of the
mixing parameters and the mass matrix texture from current and future neutrino
data in the case where $\nu_e$ and $\nu_\mu$ each mix primarily with one other
neutrino. We find that measurable CP/T violation in long-baseline experiments,
with amplitude at the level of the LSND signal, is possible given current
experimental constraints. Also, additional oscillation effects in short- and
long-baseline experiments may be measurable in many cases. We point out that,
given separate scales for the mass-squared differences of the solar and
atmospheric oscillations, observable CP/T violation effects in neutrino
oscillations signals the existence of a sterile neutrino. We examine several
textures of the neutrino mass matrix and determine which textures can have
measurable CP/T violation in neutrino oscillations in long-baseline
experiments. We also briefly discuss some possible origins of the neutrino mass
terms in straightforward extensions of the Standard Model.


title: Effects of the supersymmetric phases on the neutral Higgs sector

abstract:
  By using the effective potential approximation and taking into account the
dominant top quark and scalar top quark loops, radiative corrections to MSSM
Higgs potential are computed in the presence of the supersymmetric CP-violating
phases. It is found that, the lightest Higgs scalar remains essentially CP-even
as in the CP-invariant theory whereas the other two scalars are heavy and do
not have definite CP properties. The supersymmetric CP-violating phases are
shown to modify significantly the decay rates of the scalars to fermion pairs.


title: $\theta$ Vacuum: A Matrix Model

abstract:
  We model the effects of a large number of zero modes for $N_f$ species of
quarks at finite vacuum angle $\theta$, using a matrix model with gaussian
weights constrained by the topological susceptibility and compressibility. The
quenched free energy exhibits a cusp at $\theta <\pi$ that is sensitive to the
accuracy of the numerical analysis and the maximum density of winding modes.
Our results bear much in common with recent lattice simulations by Schierholtz
and others. The unquenched free energy exhibits similar sensitivities, but for
small quark masses or a large density of zero modes the results are in
agreement with those derived using chiral effective Lagrangians.


title:
Predicting the critical density of topological defects in O(N) scalar
  field theories

abstract:
  O(N) symmetric $\lambda \phi^4$ field theories describe many critical
phenomena in the laboratory and in the early Universe. Given N and $D\leq 3$,
the dimension of space, these models exhibit topological defect classical
solutions that in some cases fully determine their critical behavior. For N=2,
D=3 it has been observed that the defect density is seemingly a universal
quantity at T_c. We prove this conjecture and show how to predict its value
based on the universal critical exponents of the field theory. Analogously, for
general N and D we predict the universal critical densities of domain walls and
monopoles, for which no detailed thermodynamic study exists. This procedure can
also be inverted, producing an algorithm for generating typical defect networks
at criticality, in contrast to the canonical procedure, which applies only in
the unphysical limit of infinite temperature.


title: Relativistic four-quark equations and cryptoexotic mesons spectroscopy

abstract:
  The four-quark equations are found in the framework of the dispersion
relation technique. The approximate solutions of these equations using the
method based on the extraction of leading singularities of the amplitudes are
obtained. The four-quark amplitudes of cryptoexotic mesons including the quarks
of three flavours (u, d, s) are calculated. The mass values of low-lying
cryptoexotic mesons are calculated.


title:
Supersymmetric Hybrid Inflation: Explaining the Spectrum of Cosmological
  Perturbations through a Multiple-Stage Inflationary Model

abstract:
  We explore the possibility that a multiple-stage inflationary scenario based
on supersymmetric GUT models, can account for the break at $k_b \simeq 0.05
h/Mpc$ in the power spectrum of galaxy clustering, while it reproduces the
angular power spectrum of cosmic microwave background anisotropies.


title: Positronium S state spectrum: analytic results at O(m alpha^6)

abstract:
  We present an analytic calculation of the O(m alpha^6) recoil and radiative
recoil corrections to energy levels of positronium nS states and their
hyperfine splitting. A complete analytic formula valid to O(m alpha^6) is given
for the spectrum of S states. Technical aspects of the calculation are
discussed in detail. Theoretical predictions are given for various energy
intervals and compared with experimental results.


title: Semileptonic B -> a_1 l nu decay in QCD

abstract:
  The form factors and the branching ratio of the "B -> a_1 l nu" decay are
calculated in framework of QCD sum rules. A comparison of our results on form
factors and branching ratio with the results from constituent quark model is
presented.


title: Axionic Boson Stars in Magnetized Conducting Media

abstract:
  Axions are possible candidates of dark matter in the present Universe. They
have been argued to form axionic boson stars with small masses
$10^{-14}M_{\odot}\sim 10^{-11}M_{\odot}$. Since they possess oscillating
electric fields in a magnetic field, they dissipate their energies in
magnetized conducting media such as white dwarfs or neutron stars. At the same
time the oscillating electric fields generate a monochromatic radiation with
energy equal to mass of the axion. We argue that the effect of the energy
dissipation can be seen in the old white dwarfs. In particular, We show that
colliding with sufficiently cooled white dwarfs, plausible candidates of MACHO,
the axionic boson stars dissipate their energies in the dwarfs and heat up the
dwarfs. Consequently the white dwarfs in the halo can emit detectable amount of
thermal radiations with the collision. On the other hand, the monochromatic
radiations can be seen only during the collision; a period of the dwarf passing
the axionic boson star. Assuming that MACHO are dark white dwarfs, we show that
there is a threshold in luminosity function of the white dwarfs below which the
number of the white dwarfs in the halo increase discontinuously. The threshold
in the luminosity function is expected to be located around
$10^{-5.5}L_{\odot}\sim 10^{-7}L_{\odot}$. Its precise value is determined by
the mass of the axionic boson stars dominant in the halo.


title:
Rapidity-Separation Dependence and the Large Next-to-Leading Corrections
  to the BFKL Equation

abstract:
  Recent concerns about the very large next-to-leading logarithmic (NLL)
corrections to the BFKL equation are addressed by the introduction of a
physical rapidity-separation parameter $\Delta$. At the leading logarithm (LL)
this parameter enforces the constraint that successive emitted gluons have a
minimum separation in rapidity, $y_{i+1}-y_i>\Delta$. The most significant
effect is to reduce the BFKL Pomeron intercept from the standard result as
$\Delta$ is increased from 0 (standard BFKL). At NLL this $\Delta$-dependence
is compensated by a modification of the BFKL kernel, such that the total
dependence on $\Delta$ is formally next-to-next-to-leading logarithmic. In this
formulation, as long as $\Delta\gtrsim2.2$ (for $\alpha_{s}=0.15$): (i) the NLL
BFKL pomeron intercept is stable with respect to variations of $\Delta$, and
(ii) the NLL correction is small compared to the LL result. Implications for
the applicability of the BFKL resummation to phenomenology are considered.


title:
Is it always possible to discover supersymmetry broken at TeV scale at
  LHC?

abstract:
  We show that the search for supersymmetry at LHC will be very problematic for
the particular case of nonuniversal relations among gaugino masses. Namely, if
gluino, first chargino and LSP masses are closed to each other it would be very
difficult to discover supersymmetry even if sparticle masses are lighter than 1
TeV.


title: Quantum Mechanics of Neutrino Oscillations - Hand Waving for Pedestrians

abstract:
  Why Hand Waving? All calculations in books describe oscillations in time. But
real experiments don't measure time. Hand waving is used to convert the results
of a "gedanken time experiment" to the result of a real experiment measuring
oscillations in space. Right hand waving gives the right answer; wrong hand
waving gives the wrong answer. Many papers use wrong handwaving to get wrong
answers. This talk explains how to do it right and also answers the following
questions:
  1. A neutrino which is a mixture of two mass eigenstates is emitted with muon
in the decay of a pion at rest. This is a a "missing mass experiment" where the
muon energy determines the neutrino mass. Why are the two mass states coherent?
  2. A neutrino which is a mixture of two mass eigenstates is emitted at time
t=0. The two mass eigenstates move with different velocities and arrive at the
detector at different times. Why are the two mass states coherent?
  3. A neutrino is a mixture of two overlapping wave packets with different
masses moving with different velocities. Will the wave packets eventually
separate? If yes, when?


title: Local cosmic strings from Pseudo-anomalous U(1)

abstract:
  Local cosmic strings solutions are introduced in a model with a
pseudo-anomalous U(1) gauge symmetry. Such a symmetry is present in many
superstring compactification models. The coupling of those strings with the
axion necessary in order to cancel the anomalies does not prevent them from
being local, even though their energy per unit length is found to diverge
logarithmically. We discuss briefly the formation of such strings and the
phenomenological constraints that apply to their parameters.


title:
New Variables For Neutrino Oscillation Diagnostics at Superkamiokande
  and the Sudbury Neutrino Observatory

abstract:
  The SuperKamiokande collaboration has presented results on the observation of
solar neutrinos. The Sudbury Neutrino Observatory (SNO) is also expected to go
on-line in the near future. We propose several new variables, insensitive to
the absolute flux of the initial solar neutrino beam, which probe the shape of
the observed spectrum at these experiments and can sensitively signal neutrino
oscillations. One class of such variables involves normalised moments of the
distributions recorded at the two facilities while another variable, specific
to SNO, depends on the integrated charged and neutral current signals. The
utility of these variables in the context of supernova neutrinos, both from the
collapse epoch and the post-bounce era, is also emphasised. It is shown that,
notwithstanding the imprecise nature of the information about the initial
neutrino spectra from a supernova, oscillations can be detected using these
variables and it will be possible to distinguish between the alternatives of
oscillation to a sequential neutrino {\em vis-a-vis} that to a sterile
neutrino.


title: Techniques for Calculating two-loop Diagrams

abstract:
  Methods developed by the Bielefeld-DESY-Dubna collaboration in recent years
are: DIANA (DIagram ANAlyser), a program to produce ``FORM input'' for Feynman
diagrams, starting from the Feynman rules; methods to calculate scalar
diagrams: Taylor expansion in small momenta squared in connection with a
mapping and the Pad\'{e} method to sum the series. Recently program packages
for the large mass expansion were written and applied to the $Z \to b\bar{b}$
decay. Reviews of these activities were presented in the proceedings of the
Ustro\'{n} '97 and Rheinsberg '98 conferences. Here we concentrate on recent
developements in the large mass expansion, applied to the two-loop contribution
of the $Z \to b\bar{b}$ decay in the $m_b=0$ approximation, taking into account
higher order terms of the expansion in $M_W^2/m_t^2$.


title: Testing neutrino instability with active galactic nuclei

abstract:
  Active galactic nuclei and gamma ray bursts at cosmological distances are
sources of high-energy electron and muon neutrinos and provide a unique test
bench for neutrino instability. The typical lifetime-to-mass ratio one can
reach there is $\tau/m\sim 500 Mpc/cE_{\nu}\sim 500$ s/eV. We study the rapid
decay channel $\nu_i\to\nu_j+\phi$, where $\phi$ is a massless or very light
scalar (possibly a Goldstone boson), and point out that one can test the
coupling strength of $g_{ij}\nu_i\nu_j$ down to $g_{ij}\lsim 10^{-8} eV/m$ by
measuring the relative fluxes of $\nu_{e}$, $\nu_{\mu}$ and $\nu_{\tau}$. This
is orders of magnitude more stringent bound than what one can obtain in other
phenomena, e.g. in neutrinoless double beta decay with scalar emission.


title: Big bang nucleosynthesis limit on N_nu

abstract:
  Recently we presented a simple method for determining the correlated
uncertainties of the light element abundances expected from big bang
nucleosynthesis, which avoids the need for lengthy Monte Carlo simulations. We
now extend this approach to consider departures from the Standard Model, in
particular to constrain any new light degrees of freedom present in the thermal
plasma during nucleosynthesis. Since the observational situation regarding the
inferred primordial abundances has not yet stabilized, we present illustrative
bounds on the equivalent number of neutrino species N_nu for various
combinations of individual abundance determinations. Our 95% C.L. bounds on
N_nu range between 2 and 4, and can easily be reevaluated using the technique
provided when the abundances are known more accurately.


title:
Phenomenological evidence for the energy dependence of the $\eta-\eta'$
  mixing angle

abstract:
  A phenomenological analysis on various decay processes is performed using an
energy-dependent $\eta-\eta'$ mixing angle scheme. Special attention is given
to the radiative couplings between lowest-lying vector and pseudoscalar mesons.
The agreement between our predictions and the experimental values is
remarkable. This analysis opens a connection to two-angle fits in the
$\eta-\eta'$ sector.


title: Neutrino Masses in Supersymmetry: R-Parity and Leptogenesis

abstract:
  In the supersymmetric standard model of particle interactions, R-parity
nonconservation is often invoked to obtain nonzero neutrino masses. We point
out here that such interactions of the supersymmetric particles would erase any
pre-existing lepton or baryon asymmetry of the universe before the electroweak
phase transition through the $B + L$ violating sphaleron processes. We then
show how neutrino masses may be obtained in supersymmetry (assuming R-parity
conservation) together with successful leptogenesis and predict the possible
existence of new observable particles.


title: Quantum Field Theory of Meson Mixing

abstract:
  We have developed a quantum field theoretic framework for scalar and
pseudoscalar meson mixing and oscillations in time. The unitary inequivalence
of the Fock space of base (unmixed) eigenstates and the physical mixed
eigenstates is proven and shown to lead to a rich condensate structure. This is
exploited to develop formulas for two flavor boson oscillations in systems of
arbitrary boson occupation number. The mixing and oscillation can be understood
in terms of vacuum condensate which interacts with the bare particles to induce
non-trivial effects. We apply these formulas to analyze the mixing of $\eta$
with $\eta'$ and comment on the $K_L K_S$ system. In addition, we consider the
mixing of boson coherent states, which may have future applications in the
construction of meson lasers.


title: On the Intermittency and Chaos in High Energy Collisions

abstract:
  It is shown that an event sample from the Monte Carlo simulation of a random
cascading \alpha model with fixed dynamical fluctuation strength is
intermittent but not chaotic, while the variance of dynamical fluctuation
strength in different events will result in both the intermittency and the
chaotic behavior. This shows that fractality and chaoticity are two connected
but different features of non-linear dynamics in high energy collisions.


title: Operator Product Expansion, Renormalization Group and Weak Decays

abstract:
  A non-technical description of the Operator Product Expansion and
Renormalization Group techniques as applied to weak decays of mesons is
presented. We use this opportunity to summarize briefly the present status of
the next-to-leading QCD corrections to weak decays and their implications for
the unitarity triangle, the ratio epsilon prime/epsilon, the radiative decay
B-> s gamma, and the rare decays K^+ -> pi^+ nu barnu and K_L to pi^0 nu barnu.


title: Some Remarks on the Final State Interactions in $B\to \pi K$ Decays

abstract:
  Careful discussions are made on some points which are met in studying B decay
final state interactions, taking the $B^0\to \pi^+ K^-$ process as an example.
We point out that $\pi$--exchange rescatterings are not important, whereas for
$D^*$ and $D^{**}$ exchanges, since the $B^0\to D^+D_s^-$ decay has a large
branching ratio their contributions may be large enough to enhance the $B\to
\pi K$ branching ratio significantly.
  However our estimates fail to predict a large enhancement.


title: The Production of Single t-Quarks at LEP and HERA

abstract:
  We study the possibility to produce single t-quarks both at LEP II and HERA.
While within the Standard Model such reactions are not observable, the
possibility exists in a wide class of dynamical models for the fermion mass
generation. General arguments, based on hierarchical and democratic symmetries
are used to arrive at t-production rates which are detectable.


title: Lectures on the foundations of QCD

abstract:
  The paper is withdrawn by the author. This was an embryon of the book which
has now been published with World Scientific under the title "Lectures on
Quantum Chromodynamics". See http://www.wspc.com.sg/books/physics/4443.html,
where the beginning of the book will soon be available in the pdf format.


title: Stabilization of Chromomagnetic Fields at High Temperature?

abstract:
  It is well known that a tachyonic mode appears in the spectrum of Yang--Mills
theory with a static uniform magnetic field, and that the free energy has an
(unstable) minimum at finite magnetic field. It is argued that spontaneous
generation of magnetic field does not take place at high temperature due to
nonperturbative magnetic screening. Furthermore, the dispersion relation for
gauge field fluctuations in an external magnetic field at high temperature is
solved. The lowest energy mode is stable against spontaneous generation of
magnetic fields since it acquires a thermal mass. However, the resummed free
energy (by necessity computed in the imaginary time formalism) still shows an
instability, unaffected by the resummation, since the self-energy is vanishing
at static Matsubara frequency.


title: The \tau to \omega,\phi \pi \nu \tau Decays in the Chiral Model

abstract:
  The \tau \to \omega,\phi \pi^- \nu_\tau decays of the \tau lepton are studied
using the method of phenomenological SU(3) * SU(3) chiral Lagrangians. It is
shown that the obtained value for the \tau \to \phi \pi \nu_\tau decay
probability is very sensitive to deviations from the mixing angle. Calculated
partial widths for these decays are compared with the available experimental
and theoretical data.


title:
The Parton-Hadron Phase Transition in Central Nuclear Collisions at the
  CERN SPS

abstract:
  A selection of recent data referring to Pb+Pb collisions at the SPS CERN
energy of 158 GeV per nucleon is presented which might describe the state of
highly excited strongly interacting matter both above and below the
deconfinement to hadronization (phase) transition predicted by lattice QCD. A
tentative picture emerges in which a partonic state is indeed formed in central
Pb+Pb collisions which hadronizes at about T = 185 MeV, and expands its volume
more than tenfold, cooling to about 120 MeV before hadronic collisions cease.
We suggest further that all SPS collisions, from central S+S onward, reach that
partonic phase, the maximum energy density increasing with more massive
collision systems.


title: A Two Channel Calculation of Screening Corrections

abstract:
  We present a two channel eikonal calculation in which the rescattering
through a diffractive channel is included in addition to the elastic channel.
Considering the spread of the experimental data, we find that we can obtain a
very good description of $\s_{tot}$, $\s_{el}$ and $B_{el}$ in the ISR -
Tevatron energy range. In this range of energy the diffractive channel, that
was included in our calculation, leads to a ratio of $\s_{SD}/\s_{el}$ which
varies between 1 and 0.5 for $20 GeV \leq \sqrt{s} \leq 14 TeV$ in agreement
with the experimental data. The calculated survival probability of dijet
production with a large rapidity gap is consistent with the data.


title: Destruction of Fermion Zero Modes on Cosmic Strings

abstract:
  I examine the existence of zero energy fermion solutions (zero modes) on
cosmic strings in an SO(10) grand unified theory. The current carrying
capability of a cosmic string formed at one phase transition can be modified at
subsequent phase transitions. I show that the zero modes may be destroyed and
the conductivity of the string altered. I discuss the cosmological implications
of this, and show that it allows vorton bounds to be relaxed.


title: A real CKM matrix?

abstract:
  The hypothesis of a real Cabibbo-Kobayashi-Maskawa matrix has been considered
and found to be disfavoured by present measurements even when neglecting
results from CP violation in neutral Kaon decay. This result contradicts
statements reported in hep-ph/9810333.


title: Soft Particle Emission Accompanying Dijet Photoproduction

abstract:
  The intensity of the soft bremsstrahlung depends on the colour charges of the
hard- scattered partons. This intensity is larger in dijet production with
resolved photons by the factor C_A/C_F=9/4 in comparison with direct
photoproduction for particular configurations.
  It is investigated how these effects are reflected in Monte Carlo models.


title:
Upsilon photoproduction at HERA compared to estimates of perturbative
  QCD

abstract:
  We estimate the cross section for gamma p -> Upsilon p by two independent
methods. First, by studying the corrections to the naive leading-order QCD
formula and, second, by using parton-hadron duality. The estimates are in good
agreement with each other and with the recent measurements of the cross section
at HERA.


title:
QCD-Motivated BSE-SDE Framework For Quark-Dynamics Under Markov-Yukawa
  Transversality

abstract:
  This article aims at an integrated formulation of BSE's for 2- and 3-quark
hadrons under the Markov-Yukawa Transversality Principle (MYTP) which provides
a deep interconnection between the 3D and 4D BSE forms, and hence offers a
unified treatment of 3D spectroscopy with 4D quark-loop integrals for hadronic
transitions. For the actual dynamics, an NJL-type realization of DBchiS is
achieved via the interplay of Bethe-Salpeter (BSE) and Schwinger-Dyson (SDE)
equations, which are simultaneously derivable from a chiral Lagrangian with a
gluonic (Vector-exchange) 4-fermion interaction of `current' uds quarks,
specifically addressing the non-perturbative regime. A prior critique of the
literature on various aspects of the non-perturbative QCD problem, on the basis
of some standard criteria, helps converge on a BSE-SDE framework with a 3D-4D
interconnection based on MYTP. This framework is then employed for a systematic
self-contained presentation of 2- and 3-quark dynamics on the lines of
MYTP-governed DBchiS, with enough calculational details illustrating the
techniques involved. Specific topics include: 3D-4D interconnection of qbar q
and qqq wave functions by Green's Function methods; pion form factor; 3-hadron
form factors with unequal mass loops; SU(2) mass splittings; Vacuum condensates
(direct and induced); Complex H.O. techniques and SO(2,1) algebras for Baryon
Spectroscopy; plus others. PACS: 12.90.+b ; 11.10.St ; 12.70.+q ; 12.38.Lg


title:
Determination of the pattern of nuclear binding from the data on the
  lepton-nucleus deep inelastic scattering

abstract:
  Nucleon structure function ratios r(x) = F2A(x)/F2D(x) measured in the range
of atomic masses A larger or equal 4 are analyzed with the aim to determine the
pattern of the x and A dependence of F2(x) modifications caused by nuclear
environment. It is found that the x and A dependence of the deviations of the
r(x) from unity can be factorized in the entire range of x. The characteristic
feature of the factorization is represented with the three cross-over points
x_i, i = 1 -- 3 in which r(x) = 1 independently of A. In the range x lager than
0.7 the pattern of r(x) is fixed with x_3 = 0.84 +/- 0.01.
  The pattern of the x dependence is compared with theoretical calculations of
Burov, Molochkov and Smirnov to demonstrate that evolution of the nucleon
structure as a function of A occurs in two steps, first for A less or equal 4
and second for A larger than 4. The long-standing problem of the origin of the
EMC effect is understood as the modification of the nucleon structure in the
field responsible for the binding forces in a three-nucleon system.


title: Neutrino- Photon Interactions at Low Energy

abstract:
  We discuss $\nu - \gamma$ interactions in the presence of a homogeneous
magnetic field with energies less than pair production threshold. The neutrinos
are taken to be massless with only standard-model couplings. The magnetic field
fulfills the dual purpose of inducing an effective neutrino-photon vertexes and
of modifying the photon dispersion relation. Our conclusion is $\nu - \gamma$
interactions are too weak to be of importance for pulsar physics.


title: Cherenkov radiation by neutrinos

abstract:
  We discuss the Cherenkov process $\nu\to\nu\gamma$ in the presence of a
homogeneous magnetic field. The neutrinos are taken to be massless with only
standard-model couplings. The magnetic field fulfills the dual purpose of
inducing an effective neutrino-photon vertex and of modifying the photon
dispersion relation such that the Cherenkov condition $\omega<|{\bf k}|$ is
fulfilled. For a field strength $B_{\rm crit}=m_e^2/e=4.41\times10^{13} Gauss$
and for $E=2m_e$ the Cherenkov rate is about $6\times10^{-11}s^{-1}$.


title:
Nucleon matrix elements of twist-3 and 4 operators from the instanton
  vacuum

abstract:
  The spin-dependent twist-3 and 4 nucleon matrix elements d^(2) and f^(2)
describing power corrections to the Bjorken and Ellis-Jaffe sum rules are
computed in the instanton vacuum. A systematic expansion in the small packing
fraction of the instanton medium, rho / R << 1, is performed. We find that the
twist-3 matrix element d^(2) is suppressed [of order (rho / R)^4], while the
twist-4 matrix element f^(2) is of order unity. Numerically, d^(2) << f^(2).
The small value of d^(2) \sim 10^{-3} obtained from instantons is consistent
with the recent E143 measurements of the structure function g_2, where d^(2)
enters at the same level as the twist-2 contribution.


title: Conformal invariance and QCD Pomeron vertices in the $1/N_c$ limit

abstract:
  Using the dipole framework for QCD at small x in the 1/N_c limit, we derive
the expression of the 1 -> p dipole multiplicity density in momentum space.
This gives an analytical expression for the 1 -> p QCD Pomeron amplitudes in
terms of one-loop integration of effective vertices in transverse momentum.
Conformal invariance and a Hilbert space construction for dipole correlation
functions are the main tools of the derivation. Relations with conformal field
theories in the classical limit are discussed.