title:
Renormalon Model of Twist-4 Corrections to the Pion Distribution
  Amplitude

abstract:
  In this paper we describe a renormalon-inspired model of twist--4 power
corrections to the light-cone pion distribution amplitude, and compare it to
the results obtained using the conformal wave expansion. We find that the
overall functional form predicted in this renormalon model is similar to the
one predicted in the standard approach to higher twist contributions involving
an expansion in conformal operators. However, small discrepancies at the
end-points allow for a discussion on the convergence properties of the
conformal expansion.


title: Top quark and charged Higgs at the Tevatron-Run II

abstract:
  We shortly review the top quark decay into charged Higgs, and present new
results on its production at the upgraded Tevatron. We have computed the MSSM
cross-section for single charged Higgs in association with the top quark beyond
the regime of on-shell t t-bar production followed by the decay t -> H+ b. Our
results are higher than recent results in the literature. In the case where H+
belongs to the Higgs sector of the MSSM, we show that the leading
supersymmetric radiative corrections may substantially increase the
cross-section. Overall we find that the charged Higgs production process can be
complementary to the neutral Higgs production processes W\Phi and b b-bar\Phi,
which have been studied under similar circumstances. Since the neutral and
charged Higgs channels are enhanced in the same region of the parameter space,
the simultaneous detection of all these processes could be essential for an
effective experimental underpinning of the nature of these Higgs particles at
the Tevatron-Run II.


title: Heavy-light decay constants from relativistic Nf=2,0 QCD

abstract:
  We present results on an analysis of the decay constants fB and fBs with two
flavours of sea quark. The calculation has been carried out on 3 different bare
gauge couplings and 4 sea quark masses at each gauge coupling, with m_pi/m_rho
ranging from 0.8 to 0.6. We employ the Fermilab formalism to perform
calculations with heavy quarks whose mass is in the range of the b-quark. A
comparison with a quenched calculation using the same action is made to
elucidate the effects due to the sea quarks.


title: Comment on the Matrix Element of $O_{11}$

abstract:
  The gluon dipole operator, $O_{11}$, has received much attention recently
because it can have a large coefficient in some SUSY extensions of the standard
model. We find that the commonly used matrix element of $O_{11}$ of Bertolini,
Eeg and Fabbrichesi is in rough (but accidental) numerical agreement with an
estimate based on dimensional analysis.


title: Effects of Scalar Leptoquarks at HERA with Polarized Protons

abstract:
  The search and the identification of Scalar Leptoquarks are analyzed for the
HERA collider. We emphasize the relevance of having polarized beams and we make
some remarks on the usefulness of en collisions.


title: Prospects and problems in fermion-pair production

abstract:
  We discuss 2f production at LC energies (f \neq t). This type of reaction has
a big event number and may give interesting hints to the existence and perhaps
to details of New Physics like susy, LQ, Z', etc. {For} any search the
radiative corrections have to be controlled carefully. An interesting challenge
for theoreticians could also be the Giga-Z option of the TESLA project.


title:
Properties of scalar--isoscalar mesons from multichannel interaction
  analysis below 1800 MeV

abstract:
  Scalar-isoscalar mesons are studied using an unitary model in three channels:
pi-pi, K-anti K and an effective 2pi-2pi.
  All the solutions, fitted to the pi-pi and K-anti K data, exhibit a wide
f0(500), a narrow f0(980) and two relatively narrow resonances, lying on
different sheets between 1300 MeV and 1500 MeV.
  These latter states are similar to the f0(1370) and f0(1500) seen in
experiments at CERN. Branching ratios are compared with available data. We have
started investigations of some crossing symmetry and chiral constraints imposed
near the pi-pi threshold on the scalar-isoscalar, scalar-isotensor and P-wave
pi-pi amplitudes.


title: The polarised gluon density Delta G from di-jet events in NLO

abstract:
  A feasibility study to extract the polarised gluon density from di-jet events
at HERA in next-to-leading order is presented. It is shown that when taking
next-to-leading order effects into account the asymmetries at HERA remain
measurable and sensitive to the polarised gluon distribution. They can be used
to extract the polarised gluon density in the proton in the region
0.005<x_g<0.4.


title: Extracting V_{ub} Without Recourse to Structure Functions

abstract:
  We present a closed form expression for |V_{ub}|^2/ |V_{tb} V_{ts}^*|^2 in
terms of the endpoint photon and lepton spectra from the inclusive decays B ->
X_s\gamma and B -> X_u\ell\nu, respectively, which includes the resummation of
the endpoint logs at next to leading order and is completely independent of the
B meson structure function. The use of this expression for extracting V_{ub}
would eliminate the large systematic errors usually incurred due to the
modeling of the heavy quarks' Fermi motion.


title:
Gauge invariance and finite width effects in radiative two-pion tau
  lepton decay

abstract:
  The contribution of the rho^{\pm} vector meson to the tau -> pi pi nu gamma
decay is considered as a potential source for the determination of the magnetic
dipole moment of this light vector meson. In order to keep gauge-invariance of
the whole decay amplitude, a procedure similar to the fermion loop-scheme for
charged gauge bosons is implemented to incorporate the finite width effects of
the rho^{\pm} vector meson. The absorptive pieces of the one-loop corrections
to the propagators and electromagnetic vertices of the rho^{\pm} meson and
W^{\pm} gauge boson have identical forms in the limit of massless particles in
the loops, suggesting this to be a universal feature of spin-one unstable
particles. Model-dependent contributions to the tau -> pi pi nu gamma decay are
suppressed by fixing the two-pion invariant mass distribution at the rho meson
mass value. The resulting photon energy and angular distribution is relatively
sensitive to the effects of the rho magnetic dipole moment.


title: Semileptonic and non-leptonic B_c decays

abstract:
  We make predictions for the exclusive semileptonic and the non-leptonic decay
widths of the B_c meson. We evaluate the B_c semileptonic form factors for
different decay channels in a relativistic model, and use factorization to
obtain the non-leptonic decay widths.


title:
Relativistic Hadron-Hadron Collisions in the Ultra-Relativistic Quantum
  Molecular Dynamics Model (UrQMD)

abstract:
  Hadron-hadron collisions at high energies are investigated in the
Ultra-relativistic-Quantum-Molecular-Dynamics approach (UrQMD). This
microscopic transport model is designed to study pp, pA and A+A collisions. It
describes the phenomenology of hadronic interactions at low and intermediate
energies ($\sqrt s <5$ GeV) in terms of interactions between known hadrons and
their resonances. At high energies, $\sqrt s >5$ GeV, the excitation of color
strings and their subsequent fragmentation into hadrons dominates the multiple
production of particles in the UrQMD model. The model shows a fair overall
agreement with a large body of experimental h-h data over a wide range of h-h
center-of-mass energies. Hadronic reaction data with higher precision would be
useful to support the use of the UrQMD model for relativistic heavy ion
collisions.


title:
Cosmological nucleosynthesis and active-sterile neutrino oscillations
  with small mass differences: The resonant case

abstract:
  We have provided a numerical study of the influence of the resonant
active-sterile neutrino oscillations between electron and sterile neutrinos, on
the primordial production of helium-4. The evolution of the neutrino ensembles
was followed selfconsistently with the evolution of the nucleons, using exact
kinetic equations for the neutrino density matrix and the nucleon number
densities in momentum space, from the time of neutrino decoupling till the
freeze-out of nucleons at 0.3 MeV.
  The exact kinetic approach enabled us to study precisely the neutrino
depletion, spectrum distortion and neutrino mixing generated asymmetry due to
oscillations at each momentum mode, and to prove that their effect on
nucleosynthesis is considerable.
  We have calculated the dependence of the primordially produced helium-4 Y_p
on the oscillation parameters for the full range of mixing parameters of the
model of oscillations with small mass differences less than 10^{-7} eV^2. We
have obtained iso-helium contours on the oscillation parameters plane.
Cosmological constraints on oscillation parameters, more precise than the
existing ones, were extracted, due to the exact kinetic approach and the proper
account for the neutrino spectrum distortion and the oscillations generated
asymmetry.


title: Considerations on anomalous vector boson couplings

abstract:
  We discuss the meaning of anomalous vector boson self couplings. Implications
of present experimental constraints for future colliders are discussed. Results
for triple vector boson production at the LHC are given.


title:
Constraints from the muon anomalous magnetic moment and $b \to s \gamma$
  on gauge-mediated supersymmetry-breaking models

abstract:
  We present a combined study of the muon anomalous magnetic moment, $a_{\mu}
\equiv (g-2)_{\mu} /2$, and $b \to s \gamma$ decay in the minimal
supersymmetric standard model with gauge-mediated supersymmetry-breaking.
Combining new experimental data on $a_{\mu}$ and the branching ratio for $b \to
s \gamma$, useful limits on the parameter space of these models are derived.
Bounds on supersymmetric particle masses as a function of $\tan \beta$ are also
presented.


title:
Split Fermions in Extra Dimensions and Exponentially Small
  Cross-Sections at Future Colliders

abstract:
  We point out a dramatic new experimental signature for a class of theories
with extra dimensions, where quarks and leptons are localized at slightly
separated parallel ``walls'' whereas gauge and Higgs fields live in the bulk of
the extra dimensions. The separation forbids direct local couplings between
quarks and leptons, allowing for an elegant solution to the proton decay
problem. We show that scattering cross sections for collisions of fermions
which are separated in the extra dimensions vanish exponentially at energies
high enough to probe the separation distance. This is because the separation
puts a lower bound on the attainable impact parameter in the collision. We
present cross sections for two body high energy scattering and estimate the
power with which future colliders can probe this scenario, finding sensitivity
to inverse fermion separations of order 10-70 TeV.


title: Chiral Boson Theory on the Light-Front

abstract:
  The {\it front form} framework for describing the quantized theory of chiral
boson is discussed. It avoids the conflict with the requirement of the
principle of microcausality as is found in the conventional equal- time
treatment. The discussion of the Floreanini-Jackiw model and its modified
version for describing the chiral boson becomes very transparent on the
light-front.


title:
On the $\xi$-Distribution of Inclusively Produced Particles in $e^+e^-$
  Annihilation

abstract:
  We discuss the momentum distributions of inclusively produced particles in
$e^+e^-$ annihilation. We show that the dependence of the position of the
maxima of the $\xi=\ln(1/z)$ spectra on the mass of the produced particles
follows naturally from the general definition of fragmentation functions when
energy-momentum conservation is correctly incorporated.


title: Top Physics at Threshold and Beyond

abstract:
  A review on theoretical aspects of top quark physics at the Linear Collider
is given with focus on the process $e^+e^-\to t\bar t$ and the presentations
given at this conference.


title:
Large CP Violation, Large Mixings of Neutrinos and Democratic-type
  Neutrino Mass Matrix

abstract:
  We propose a democratic-type neutrino mass matrix based on $Z_3$ symmetry.
This mass matrix predicts the CP violation phase, $\delta=\pi/2$, and the
mixing angle between the mass eigenstates $\nu_2$ and $\nu_3$, $\sin^2
\theta_{23}= \cos^2 \theta_{23}=1/2$ which is essential for the large
atmospheric neutrino mixing, between $\nu_\mu$ and $\nu_\tau$. In this model,
the large CP violation effect may be expected.


title: Testing lepton number violation with the reaction e,e -> mu, nu, q, q

abstract:
  We investigate the reaction e,e->mu, nu, q, q as a possible place to test the
lepton number violating interactions of singly charged scalars (Delta(L))
belonging to a SU(2)L triplet. The existence of such scalars is predicted by
some majoron models, as well as by the left-right symmetric extension of the
Standard Model. We show that this reaction may be observed in ee collision well
below the threshold of (Delta(L)). For the colliding energy E=500 GeV the mass
of the singly charged Higgs triplet may be excluded up to 2 TeV and even more,
depending on values of the appropriate Yukawa couplings.


title: Fluctuations of string tension and transverse mass distribution

abstract:
  It is shown that that Gaussian fluctuations of the string tension can account
for the "thermal" distribution of transverse mass of particles created in decay
of a colour string.


title:
Effects of CP-violating phases on Higgs boson production at hadron
  colliders in the Minimal Supersymmetric Standard Model

abstract:
  If the soft Supersymmetry (SUSY) breaking masses and couplings are complex,
then the associated CP-violating phases can in principle modify the known
phenomenological pattern of the Minimal Supersymmetric Standard Model (MSSM).
We investigate here their effects on Higgs boson production in the gluon-gluon
fusion mode at the Tevatron and the Large Hadron Collider (LHC), by taking into
account all experimental bounds available at present. The by far most stringent
ones are those derived from the measurements of the Electric Dipole Moments
(EDMs) of fermions. However, it has recently been suggested that, over a
sizable portion of the MSSM parameter space, cancellations among the SUSY
contributions to the EDMs can take place, so that the CP-violating phases can
evade those limits. We find a strong dependence of the production rates of any
neutral Higgs state upon the complex masses and couplings over such parts of
the MSSM parameter space. We show these effects relatively to the ordinary MSSM
rates as well as illustrate them at absolute cross section level at both
colliders


title: The Color-Flavor Locking Phase at T \not =0$

abstract:
  We study the color-flavor locked phase of QCD with three massless quarks at
high chemical potential and small non zero temperatures. We make use of the
recently introduced effective action to describe such a phase. We obtain the
exact order T^2 behaviour of the condensates and of the pressure by formally
comparing the derivative from the QCD functional with symmetry breaking to that
from the effective lagrangian with external sources, respecting the residual
Z_2 invariance of the color-flavor locked phase. From these exact results, but
now at a very tentative level of conjecture, we are lead to think that the
phase structure of QCD at very high density consists of two superconducting
phases and a symmetric one.


title:
Microwave background anisotropies and large scale structure constraints
  on isocurvature modes in a two-field model of inflation

abstract:
  In this paper we study the isocurvature mode contribution to the cosmic
microwave background anisotropies and the large scale structure power spectrum,
for a two-field model of inflation proposed by Linde and Mukhanov. We provide
constraints on the parameters of the model by comparing its predictions with
observations of the microwave background anisotropies, large scale structure
data on the galaxy power spectrum, and the number density of nearby galaxy
clusters. We find that such models are consistent with observations for a
narrow range of parameters. As our main result, we find that only a very small
isocurvature component is allowed, $\al \le 0.006$, for any underlying
Friedmann model. Furthermore, we give the expected resolution with which the
model parameters will be determined from future satellite missions like MAP and
Planck, for a fiducial flat $\Lambda$CDM model. We find that Planck mission
will be able to detect such small contributions, especially if polarization
information is included. The isocurvature spectral index $\niso$ will also be
determined with better than 8% precision.


title: Beyond the Standard Model at HERA

abstract:
  The prospects of physics beyond the standard model in deep inelastic
scattering are reviewed, emphasizing the search for contact interactions, for
leptoquarks and for supersymmetry with R-parity violation. R-parity violating
supersymmetry is explored as a speculative source of events with high energy
muons and missing transverse momentum, but no convincing explanation for events
of this type observed at H1 is found.


title:
Discovery Limits for Extra Gauge Bosons in e^+e^- to \nu \bar{\nu}
  \gamma

abstract:
  We study the sensitivity of the process e^+ e^- \to \nu\bar{\nu}\gamma to
extra gauge bosons, particularly W' bosons. Depending on the model, evidence
for extra W bosons in this process can be detected for W' masses up to several
TeV.


title: Using Heavy Quark Spin Symmetry in Semileptonic $B_c$ Decays

abstract:
  The form factors parameterizing the B_c semileptonic matrix elements can be
related to a few invariant functions if the decoupling of the spin of the heavy
quarks in B_c and in the mesons produced in the semileptonic decays is
exploited. We compute the form factors as overlap integral of the meson
wave-functions obtained using a QCD relativistic potential model, and give
predictions for semileptonic and non-leptonic B_c decay modes. We also discuss
possible experimental tests of the heavy quark spin symmetry in B_c decays.


title:
Mass and CKM Matrices of Quarks and Leptons, the Leptonic CP-phase in
  neutrino oscillations

abstract:
  A general approach for construction of quark and lepton mass matrices is
formulated. The hierarchy of quarks and charged leptons ("electrons") is large,
it leads using the experimental values of mixing angles to the hierarchical
mass matrix slightly deviating from one's suggested earlier by Stech and
including naturally the CP-phase.
  The same method based on the rotation of generation numbers in the diagonal
mass matrix is used in the electron-neutrino sector of theory, where neutrino
mass matrix is determined by the Majorano see-saw approach. The hierarchy of
neutrino masses, much smaller than for quarks, was used including all existing
(even preliminary) experimental data on neutrinos mixing.
  The leptonic mass matrix found in this way includes not known value of the
leptonic CP-phase. It leads to a large $\nu_\mu \nu_\tau$ oscillations and
suppresses the $\nu_e\nu_\tau$ and also $\nu_e \nu_\mu$ oscillations. The
explicit expressions for the probabilities of neutrino oscillation were
obtained in order to specify the role of leptonic CP-phase. The value of time
reversal effect (proportional to $\sin\delta'$) was found to be small $\sim
1%$. However, a dependence of the values of $\nu_e \nu_\mu, \nu_e \nu_\tau$
transition probabilities, averaged over oscillations, on the leptonic CP-phase
has found to be not small - of order of tens percent.


title: Measuring CP-violation with a neutrino factory

abstract:
  We discuss the prospects of observing leptonic CP-violation at a neutrino
factory in the context of the standard three neutrino scenario. If the large
mixing angle MSW effect turned out to account for the solar neutrino deficit,
we show that observing an asymmetry between the $\reu$ and $\reub$ oscillation
probabilities would represent an exciting experimental challenge. We determine
the portion of the parameter space where an evidence could be found as a
function of the intensity of the muon source and of the detector size for
different baselines. We discuss the consequent requirements on a neutrino
factory. We address the problems associated with asymmetries induced by the
experimental apparatus and by matter effects. Finally, we emphasize the
importance of measuring two CP-conjugated channels in order to precisely
determine $\theta_{13}$.


title: Two Skyrmion Dynamics with Omega Mesons

abstract:
  We present our first results of numerical simulations of two skyrmion
dynamics using an $\omega$-meson stabilized effective Lagrangian. We consider
skyrmion-skyrmion scattering with a fixed initial velocity of $\beta=0.5$, for
various impact parameters and groomings. The physical picture that emerges is
surprisingly rich, while consistent with previous results and general
conservation laws. We find meson radiation, skyrmion scattering out of the
scattering plane, orbiting and capture to bound states.


title:
The Effect of Shadowing on Initial Conditions, Transverse Energy and
  Hard Probes in Ultrarelativistic Heavy Ion Collisions

abstract:
  The effect of shadowing on the early state of ultrarelativistic heavy ion
collisions is investigated along with transverse energy and hard process
production, specifically Drell-Yan, $J/\psi$, and $\Upsilon$ production. We
choose several parton distributions and parameterizations of nuclear shadowing,
as well as the spatial dependence of shadowing, to study the influence of
shadowing on relevant observables. Results are presented for Au+Au collisions
at $\sqrt{s_{NN}} = 200$ GeV and Pb+Pb collisions at $\sqrt{s_{NN}} = 5.5$ TeV.


title:
Full Numerical Estimation of Neutrino Mixing Parameters from Solar
  Neutrino Data

abstract:
  We have numerically computed survival probabilities of solar neutrinos
interacting with matter via MSW mechanism in the full three generation
formalism with $\Delta m^2_{23}=2.2\times 10^{-3}$ eV$^2$. For $\theta_{13}
\lesssim 30^{\circ}$, we confirm the two regions found in the two generation
case, (1) with the most likelyhood, small $\sin^2(2\theta_{12}) \sim 0.006$,
(2) with less likelyhood, large $\sin^2(2\theta_{12}) \gtrsim 0.5$. For
$\theta_{13}\gtrsim 30^{\circ}$, we find an additional region, (3) with even
less likelyhood, $10^{-5} < \Delta m^2_{12}< 10^{-4}$ eV$^2$ and/or $10^{-4} <
\sin^2(2\theta_{12}) < 0.5$. Assuming that the case (1) is valid, we predict
that $\theta_{13} \simeq 15^\circ$.


title:
One-loop Corrected Neutrino Masses and Mixing in the Supersymmetric
  Standard Model without R-parity

abstract:
  We provide, in the R-parity violating supersymmetric standard model, a
comprehensive analysis for sneutrino minimization from the one-loop effective
scalar potential, and also for one-loop renormalized neutrino masses and mixing
by calculating the effective neutrino mass matrix in the weak basis. Applying
our results to theories with gauge mediated supersymmetry breaking, we show how
atmospheric and solar neutrino oscillations can be accommodated simultaneously
in this framework. It is observed that the one-loop correction to sneutrino
vacuum expectation values leads to a significant effect on the determination of
the neutrino masses and mixing.


title: New Physics Near 1 TeV and Above

abstract:
  A new theory makes testable predictions: (1) Higgs fields have an
unconventional equation of motion. (2) Fermions have a second-order coupling to
gauge fields. (3) Fermion propagators are modified at high energy. (4) There
are new scalar bosons which are supersymmetric partners of spin 1/2 fermions.
(5) Since W-bosons gravitate differently from fermions and massless gauge
bosons, there is a very small violation of the equivalence principle. Other
features of the theory have implications for cosmology, including the values of
cosmological parameters, a mechanism for scale-invariant density fluctuations,
and a candidate for dark matter.


title: Tri-Maximal vs Bi-Maximal Neutrino Mixing

abstract:
  It is argued that data from atmospheric and solar neutrino experiments point
strongly to tri-maximal or bi-maximal lepton mixing. While (`optimised')
bi-maximal mixing gives an excellent a posteriori fit to the data, tri-maximal
mixing is an a priori hypothesis, which is not excluded, taking account of
terrestrial matter effects.


title:
Proton-deuteron asymmetry in Drell-Yan processes and polarized
  light-antiquark distributions

abstract:
  We discuss the relation between the ratio of the proton-deuteron (pd)
Drell-Yan cross section to the proton-proton (pp) one \Delta_{(T)}
\sigma_{pd}/2 \Delta_{(T)} \sigma_{pp} and the flavor asymmetry in polarized
light-antiquark distributions. Using a recent formalism of the polarized pd
Drell-Yan process, we show that the difference between the pp and pd cross
sections is valuable for finding not only the flavor asymmetry in
longitudinally polarized antiquark distributions but also the one in
transversity distributions. It is especially important that we point out the
possibility of measuring the flavor asymmetry in the transversity distributions
because it cannot be found in W production processes and inclusive lepton
scattering due to the chiral-odd property.


title:
Effects of $A_t$ and $\mu$ phases on B and K physics in the effective
  supersymmetric models

abstract:
  In the minimal supersymmetric standard model (MSSM), the $\mu-$parameter and
the trilinear coupling $A_t$ may be generically complex and can affect various
observables at B factories. Working in the effective SUSY models and imposing
the edm constraints from Chang-Keung-Pilaftsis (CKP) mechanism, we find that
(i) there is no new large phase shift in the $B^0 - \bar{B^0}$ mixing from the
A_t and $\mu$ phases, (ii) CP violating dilepton asymmetry is smaller than
0.1%, (iii) the direct CP violation in $B\to X_s \gamma$ can be as large as
$\sim \pm 16 %$, (iv) the ${\rm Br} (B\to X_s l^+ l^-)$ can be enhanced by upto
$\sim 85 %$ compared to the standard model (SM) prediction, and its correlation
with ${\rm Br} (B \to X_s \gamma)$ is distinctly different from the minimal
supergravity scenario. Also, we find $1 \leq \epsilon_K / \epsilon_K^{SM} \leq
1.4$, and $\epsilon_K$ cannot be saturated by the A_t and $\mu$ phases alone :
namely, $|\epsilon_K^{\rm SUSY}| \leq O(10^{-5})$ if the phases of $\mu$ and
A_t are the sole origin of CP violation.


title: Signals of the quark-gluon plasma in nucleus-nucleus collisions

abstract:
  This talk is a brief overview of the present status of our understanding of
nucleus-nucleus collisions at high energy and the search for signals of the
quark-gluon plasma.


title: Detecting heavy charged Higgs bosons at the LHC with triple b-tagging

abstract:
  We investigate the charged Higgs boson signal at the LHC using its dominant
production and decay modes with triple b-tagging, i.e. $tH^- \to t\bar tb \to
b\bar bb W^+ W^-$, followed by leptonic decay of one W and hadronic decay of
the other. We consider the continuum background from the associated production
of $t\bar t$ with a b- or a light quark or gluon jet, which can be mis-tagged
as b-jet. We reconstruct the top quark masses to identify the 3rd b-jet
accompanying the $t\bar t$ pair, and use its p_T distribution to distinguish
the signal from the background. Combining this with the reconstruction of the
$H^\pm$ mass gives a viable signature over two interesting regions of the
parameter space - i.e. $\tan\beta \sim 1$ and $\sim m_t/m_b$.


title:
Second Order Corrections to the Muon Lifetime and the Semileptonic B
  Decay

abstract:
  In this article two-loop QED corrections to the muon decay and corrections of
order $\alpha_s^2$ to the semileptonic decay of the bottom quark are
considered. We compute the imaginary part of the four-loop diagrams
contributing to the corresponding fermion propagator in the limit of small
external momentum. The on-shell condition is obtained with the help of a
conformal mapping and Pad\'e approximation. Via this method we confirm the
existing results by an independent calculation.


title: Heavy Quark Production Asymmetries

abstract:
  In the hadroproduction of charm (or heavy flavours in general) in the context
of string fragmentation, the pull of a beam remnant at the other end of a
string may give a charm hadron more energy than the perturbatively produced
one. The collapse of a low-mass string to a single hadron is the extreme case
in this direction, and gives rise to asymmetries between leading and
non-leading charm hadrons. We study these phenomena within the Lund string
fragmentation model and improve the modelling in part by a consideration of
hadroproduction data. Applications include heavy quark production in any
collision between hadron-like particles such as \gamma p at HERA and pp at
HERA-B or the LHC.


title: Gauging non-local quark models

abstract:
  Gauging of effective chiral quark models with non-local regulators is
discussed in the context of solitons. In particular, we show that with the
P-exponent method the current algebra is satisfied and the charges are properly
quantized.


title: A total neutrino conversion in the Earth without a resonance

abstract:
  The neutrino oscillation enhancement in the Earth-type medium mantle - core -
mantle is discussed. It is noted that the total conversion is possible both for
a resonant matter density and a nonresonant one. A useful parameterization, for
the representation of the transition probability for neutrinos and
antineutrinos in a single plot, is proposed.


title: The heavy quark potential in pNRQCD

abstract:
  The heavy quarkonium static potential is discussed within the framework of
potential NRQCD. Some quantitative statements are made in the kinematical
situation $mv >> \Lambda_{\rm QCD}$ at the level of accuracy of the
next-to-leading order in the multipole expansion.


title:
Experimental Aspects of Supersymmety with R-Parity Violating Couplings
  at the $e^+e^-$ Linear Collider

abstract:
  A very short review on phenomenological aspects of supersymmetry with
violated R-parity at e+e- colliders is given. We present specific examples of a
search for supersymmetric particles with violating R-parity couplings at a 500
GeV~e+e- linear collider. The signal extraction, and the mass measurement in
the case of a pair production of the lightest neutralino, are performed with
the help of Monte Carlo simulation.


title: Spin polarisability of the nucleon at NLO in the chiral expansion

abstract:
  We present a calculation of the fourth-order (NLO) contribution to
spin-dependent forward Compton scattering in heavy-baryon chiral perturbation
theory. No low-energy constants, except for the anomalous magnetic moments of
the nucleon, enter at this order. The fourth-order piece of the spin
polarisability of the proton turns out to be almost twice the size of the
leading piece, with the opposite sign. This leads to the conclusion that no
prediction can currently be made for this quantity.


title:
Neutrinoless double beta decay, neutrino mass and bilinear R-parity
  breaking supersymmetry

abstract:
  Neutrinoless double beta ($\znbb$) decay violates lepton number; its absence
stringently constrains the parameters of theories beyond the standard model in
which the neutrino has a Majorana mass. R-parity violating weak-scale
supersymmetry is a prominent example of such models. Double beta decay in
supersymmetry with explicit bilinear R-parity breaking is discussed and current
limits on the $\znbb$ decay half life of $^{76}$Ge are used to extract upper
bounds on the R-parity breaking parameters of the first generation. Moreover,
it is shown that the effective Majorana neutrino mass, measured in $\znbb$
decay, is non-zero once the 1-loop corrections are taken into account even for
the case of perfect alignment ($\Lambda_i:=(< {\tilde \nu}_i > \mu - v_1
\epsilon_i) \equiv 0$) among the R-parity violating parameters.


title:
Electromagnetic Transitions of Heavy Baryons in the SU(2N_{f}) X O(3)
  Symmetry

abstract:
  Radiative decays of heavy baryons are analyzed within the Heavy Quark
Symmetry (HQS). It is shown that employing the light-diquark symmetries, the
number of electromagnetic couplings among S-wave and P-wave states as well as
those between P-wave to S-wave transitions can be reduced significantly. Using
this constituent quark model picture the phenomenological implications of some
of these decay modes are, also, discussed.


title: Polarisation in deeply virtual meson production

abstract:
  We discuss two aspects of polarisation in hard exclusive meson production:
the leading-twist selection rule for the meson helicity, and the different
partial waves of a (pi pi)-pair which may or may not be due to the decay of a
rho.


title:
Spin Dependence of Massive Lepton Pair Production in Proton-Proton
  Collisions

abstract:
  We calculate the transverse momentum distribution for the production of
massive lepton-pairs in longitudinally polarized proton-proton reactions at
collider energies within the context of perturbative quantum chromodynamics.
For values of the transverse momentum Q_T greater than roughly half the pair
mass Q, Q_T > Q/2, we show that the differential cross section is dominated by
subprocesses initiated by incident gluons, provided that the polarized gluon
density is not too small. Massive lepton-pair differential cross sections
should be a good source of independent constraints on the polarized gluon
density, free from the experimental and theoretical complications of photon
isolation that beset studies of prompt photon production. We provide
predictions for the spin-averaged and spin-dependent differential cross
sections as a function of Q_T at energies relevant for the Relativistic Heavy
Ion Collider (RHIC) at Brookhaven, and we compare these with predictions for
real prompt photon production.


title: Conformality and Brodsky

abstract:
  In this article I describe the recently-conjectured field-string duality
which suggests a class of nonsupersymmetric gauge theories which are conformal
(CGT) to leading order of 1/N and some of which may be conformal for finite N.
If the standard model becomes conformal at TeV scales, model-building on this
basis is an interesting direction. Some remarks are added about the inspiring
career of Stan Brodsky.


title: Quasi-Fixed Points and Charge and Colour Breaking in Low Scale Models

abstract:
  We show that the current LEP2 lower bound upon the minimal supersymmetric
standard model (MSSM) lightest Higgs mass rules out quasi-fixed scenarios for
string scales between 10^6 and 10^{11} GeV unless the heaviest stop mass is
more than 2 TeV. We consider the implications of the low string scale for
charge and colour breaking (CCB) bounds in the MSSM, and demonstrate that CCB
bounds from F and D-flat directions are significantly weakened. For scales less
than 10^{10} GeV these bounds become merely that degenerate scalar mass squared
values are positive at the string scale.


title: QCD Evolution of Structure Functions at Small x

abstract:
  The status of the resummation of small x contributions to the unpolarized and
polarized deep inelastic structure functions is reviewed.


title: Pion Form Factors from QCD Light-Cone Sum Rules

abstract:
  Light-cone sum rules have proved to be very useful in calculating hadronic
matrix elements for exclusive processes. I present recent applications of this
method to the pion electromagnetic form factor and to the form factors of
$\gamma^* \rho \to \pi$ and $\gamma^*\gamma \to \pi^0$ transitions.


title: Accuracy of Approximate Eigenstates

abstract:
  Besides perturbation theory, which requires, of course, the knowledge of the
exact unperturbed solution, variational techniques represent the main tool for
any investigation of the eigenvalue problem of some semibounded operator H in
quantum theory. For a reasonable choice of the employed trial subspace of the
domain of H, the lowest eigenvalues of H usually can be located with acceptable
precision whereas the trial-subspace vectors corresponding to these eigenvalues
approximate, in general, the exact eigenstates of H with much less accuracy.
Accordingly, various measures for the accuracy of the approximate eigenstates
derived by variational techniques are scrutinized. In particular, the matrix
elements of the commutator of the operator H and (suitably chosen) different
operators, with respect to degenerate approximate eigenstates of H obtained by
some variational method, are proposed here as new criteria for the accuracy of
variational eigenstates. These considerations are applied to that Hamiltonian
the eigenvalue problem of which defines the "spinless Salpeter equation." This
(bound-state) wave equation may be regarded as the most straightforward
relativistic generalization of the usual nonrelativistic Schroedinger
formalism, and is frequently used to describe, e.g., spin-averaged mass spectra
of bound states of quarks.


title:
On the nature of Coulomb corrections to the e^+e^- pair production in
  ultrarelativistic heavy-ion collisions

abstract:
  We manifest the origin of the wrong conclusion made by several groups of
authors on the absence of Coulomb corrections to the cross section of the
e^+e^- pair production in ultrarelativistic heavy-ion collisions. The source of
the mistake is connected with an incorrect passage to the limit in the
expression for the cross section. When this error is eliminated, the Coulomb
corrections do not vanish and agree with the results obtained within the
Weizs\"acker-Williams approximation.


title:
Vacuum Oscillation solutions of the Solar Neutrino Problem : A status
  Report

abstract:
  We re-examine vacuum oscillation solutions of the solar neutrino problem
taking (a) the results on total rates, electron energy spectrum, and the
seasonal variations from the 708 day SuperKamiokande data and (b) those on
total rates from the Chlorine and Gallium experiments. Best fit values for the
mixing angle and mass splitting are found for oscillations to sequential and
sterile neutrinos and the 90% C.L. allowed regions are determined.


title: Spontaneous CP Violation in Large Extra Dimensions

abstract:
  We show that in the context of large extra dimensions enough CP violation can
be obtained from the spontaneous breaking in a simple non-SUSY model, which is
usually considered not to cause the spontaneous CP violation. We estimate
\epsilon_{K} in our scenario to be of order 10^{-3} consistent with the
experimental value. We also propose a modification to the see-saw mechanism and
axion scenario to match with our model.


title: Distinguishing Higgs models at photon colliders

abstract:
  We consider the two effective couplings hZ\gamma and h\gamma\gamma involving
a neutral scalar Higgs boson with a mass around 100 GeV in the Standard Model,
in the Two Higgs Doublet Model, and in the Minimal Supersymmetric Standard
Model. The couplings can be tested at Photon Colliders, and used to distinguish
these models.


title:
Scaling of transverse energies and multiplicities with atomic number and
  energy in ultrarelativistic nuclear collisions

abstract:
  We compute how the initial energy density and produced gluon, quark and
antiquark numbers scale with atomic number and beam energy in ultrarelativistic
heavy ion collisions. The computation is based on the argument that the effect
of all momentum scales can be estimated by performing the computation at one
transverse momentum scale, the saturation momentum. The initial numbers are
converted to final ones by assuming kinetic thermalisation and adiabatic
expansion. The main emphasis of the study is at LHC and RHIC energies but it is
observed that even at SPS energies this approach leads to results which are not
unreasonable: what is usually described as a completely soft nonperturbative
process can also be described in terms of gluons and quarks. The key element is
the use of the saturation scale.


title: Neutrino Flavor Tagging in a Four-Neutrino Mixing and Oscillation Model

abstract:
  A neutrino mass dominance quantity is introduced for tagging the neutrino
flavor in the phenomenological two-parameter four neutrino mixing matrix with
two neutrino mass doublets and thorough maximal neutrino doublet mixing. While
there is no hierarchy of the neutrino masses in the neutrino flavor eigenstates
of this model, it may rather be a special hierarchy of the mass dominance
ratios in these eigenstates. A neutrino flavor hierarchy condition is
suggested: a direct link between the neutrino flavor and the flavor of the
charged leptons which interconnects the two mixing angles, theta and phi, via
the charged lepton mass ratios, with the net result tg^2 phi = (tg^2
theta)^gamma, gamma ~ 2.06. It leads to distinct inferences testable at SNO and
Super-K.


title:
Probing the Boundary of the Non-Perturbative QCD by Small Size
  Instantons

abstract:
  The lattice data on the instanton size distribution suggest an additional
O($\rho^2)$ action. The small-$\rho$ effect O($\rho^4)$ predicted by the
Operator Product Expansion (OPE) is not observed. Similar deviations are also
found for non-perturbative response to a small static color dipoles: it is O(r)
not O(r$^2$). We suggest that small instanton radii in the QCD vacuum and small
radii of the QCD strings (to which this observation relates) are consequences
of the same phenomenon: a very robust dual superconductivity in the QCD vacuum,
with relatively large Higgs VEV and surprisingly large Higgs mass.


title: General Scalar Fields as Quintessence

abstract:
  We study the cosmological evolution of scalar fields with arbitrary
potentials in the presence of a barotropic fluid (matter or radiation) without
making any assumption on which term dominates. We determine what kind of
potentials V(phi) permits a quintessence interpretation of the scalar field phi
and to obtain interesting cosmological results. We show that all model
dependence is given in terms of lambda= - V'/V only and we study all possible
asymptotic limits: lambda approaching zero, a finite constant or infinity. We
determine the equation of state dynamically for each case. For the first class
of potentials, the scalar field quickly dominates the universe behaviour, with
an inflationary equation of state allowing for a quintessence interpretation.
The second case gives the extensively studied exponential potential. While in
the last case, when lambda approaches infinity, if it does not oscillate then
the energy density redshifts faster than the barotropic fluid but if lambda
oscillates then the energy density redshift depends on the specific potential.


title: Transient topological objects in high energy collisions

abstract:
  The possible topology of quantum fluctuations which take place at the
earliest stage of high-energy processes is studied. A new exact solution of
Yang-Mills equations with fractional topological charge and carrying a single
color is found.


title:
Effects of neutrino temperatures and mass hierarchies on the detection
  of supernova neutrinos

abstract:
  Possible outcomes of neutrino events at both Super-Kamiokande and SNO for a
type-II supernova are analyzed considering the uncertainties in SN neutrino
spectra (temperature) at emission, which may complicate the interpretation of
the observed events. With the input of parameters deduced from the current
solar and atmospheric experiments, consequences of direct-mass hierarchy
$m_{\nu_{\tau}} \gg m_{\nu_{\mu}} > m_{\nu_{e}}$ and inverted-mass hierarchy
$m_{\nu_{e}} > m_{\nu_{\mu}} \gg m_{\nu_{\tau}}$ are investigated. Even if the
$\nu$ temperatures are not precisely known, we found that future experiments
are likely to be able to separate the currently accepted solutions to the solar
neutrino problem (SNP): large angle MSW, small angle MSW, and the vacuum
oscillation, as well as to distinguish between the direct and inverted mass
hierarchies of the neutrinos.


title: Gauge and Yukawa Unification in SUSY with Bilinearly Broken R-Parity

abstract:
  In a supersymmetric model where R-Parity and lepton number are violated
bilinearly in the superpotential, which can explain the solar and atmospheric
neutrino problems, we study the unification of gauge and Yukawa couplings at
the GUT scale. We show that bottom-tau Yukawa coupling unification can be
achieved at any value of $\tan\beta$, and that the strong coupling constant
prediction from unification of gauge couplings is closer to the experimental
value compared with the MSSM. We also study the predictions for $V_{cb}$ in a
Yukawa texture ans\"atze.


title: Flavor Decomposition of the Nucleon

abstract:
  I review some recent developments in the study of quark flavor distributions
in the nucleon, including (i) valence quark distributions and the quark-hadron
duality prediction for the x -> 1 d/u ratio (ii) sea quark asymmetries and
electromagnetic form factors (iii) strange quarks in the nucleon.


title:
Factorization of tree QCD amplitudes in the high-energy limit and in the
  collinear limit

abstract:
  In the high-energy limit, we compute the gauge-invariant three-parton forward
clusters, which in the BFKL theory constitute the tree parts of the NNLO impact
factors. In the triple collinear limit, we obtain the polarized
double-splitting functions. For the unpolarized and the spin-correlated
double-splitting functions, our results agree with the ones obtained by
Campbell-Glover and Catani-Grazzini, respectively. In addition, we compute the
four-gluon forward cluster, which in the BFKL theory forms the tree part of the
NNNLO gluonic impact factor. In the quadruple collinear limit we obtain the
unpolarized triple-splitting functions, while in the limit of a three-parton
central cluster we derive the Lipatov vertex for the production of three
gluons, relevant for the calculation of a BFKL ladder at NNLL accuracy.
Finally, motivated by the reorganization of the color in the high-energy limit,
we introduce a color decomposition of the purely gluonic tree amplitudes in
terms of the linearly independent subamplitudes only.


title: Experimental Constraints on Four-Neutrino Mixing

abstract:
  It is shown that at least four massive neutrinos are needed in order to
accommodate the evidences in favor of neutrino oscillations found in solar and
atmospheric neutrino experiments and in the LSND experiment. Among all
four-neutrino schemes, only two are compatible with the results of all neutrino
oscillation experiments. These two schemes have a mass spectrum composed of two
pairs of neutrinos with close masses separated by the "LSND gap" of the order
of 1 eV.


title:
The SUSY EW-like corrections to top pair production in photon-photon
  collisions

abstract:
  We studied the one-loop contributions of the gaugino-Higgsino-sector to the
process of top-pair production via $\gamma \gamma$ fusion at NLC in frame of
the Minimal Supersymmetric Model(MSSM). We find that the corrections to $\gamma
\gamma \to t\bar{t}$ and $e^+ e^- \to \gamma \gamma \to t\bar{t}$ are found to
be significant and can approach to a few percent and one percent, respectively.
Furthermore, the dependences of the corrections on the supersymmetric
parameters are also investigated. The corrections are not sensitive to
$M_{SU(2)}$ (or $|\mu|$) when $M_{SU(2)}~>>~|\mu|$
  (or $|\mu|~>>~M_{SU(2)}$) and are weakly dependent on the $\tan{\beta}$ with
$M_Q$ (or $|\mu|$) being large enough. But they are sensitive to the c.m.s.
energy of the incoming photons.


title:
Reheating Temperature and Inflaton Mass Bounds from Thermalization After
  Inflation

abstract:
  We consider the conditions for the decay products of perturbative inflaton
decay to thermalize. The importance of considering the full spectrum of
inflaton decay products in the thermalization process is emphasized. It is
shown that the delay between the end of inflaton decay and thermalization
allows the thermal gravitino upper bound on the reheating temperature to be
raised from 10^{8} GeV to as much as 10^{12} GeV in realistic inflation models.
Requiring that thermalization occurs before nucleosynthesis imposes an upper
bound on the inflaton mass as a function of the reheating temperature, m_{S} <
10^{10} (T_{R}/1 GeV)^{7/9} GeV. It is also shown that even in realistic
inflation models with relatively large reheating temperatures, it is
non-trivial to have thermalization before the electroweak phase transition
temperature. Therefore the thermal history of the Universe is very sensitive to
details of the inflation model.


title: Nucleon Form Factors '99

abstract:
  We review recent progress in the experimental knowledge of and theoretical
speculations about nucleon form factors, with special emphasis on the large Q2
region.


title:
CP and T violation in long baseline experiments with low energy neutrino
  from muon storage ring

abstract:
  Stimulated by the idea of PRISM, a very high intensity muon ring with rather
low energy, we consider possibilities of observing CP-violation effects in
neutrino oscillation experiments. More than 10% of CP-violation effect can be
seen within the experimentally allowed region. Destructive sum of matter effect
and CP-violation effect can be avoided with use of initial nu_e beam. We
finally show that the experiment with (a few) x 100 MeV of neutrino energy and
(a few) x 100 km of baseline length, which is considered in this paper, is
particularly suitable for a search of CP violation in view of statistical
error.


title: Gluonia, Scalar and Hybrid Mesons in QCD

abstract:
  For some experimental guidelines of the next millenium, I review the
determinations of the masses, decays and mixings of the gluonia, scalar and
hybrid mesons from QCD spectral sum rules and low-energy theorems, and compare
them with the lattice.


title: On the Use of Discrete Light-Cone Quantization to Compute Form Factors

abstract:
  Techniques for the field-theoretic calculation of a form factor are described
and applied to a dressed-fermion state of a (3+1)-dimensional model
Hamiltonian. Discrete light-cone quantization plays the crucial role as the
means by which Fock-state wave functions are computed. An ultraviolet infinity
is controlled by Pauli-Villars regularization.


title: An effective Lagrangian approach for unstable particles

abstract:
  We propose a novel procedure for handling processes that involve unstable
intermediate particles. By using gauge-invariant effective Lagrangians it is
possible to perform a gauge-invariant resummation of (arbitrary) self-energy
effects. For instance, gauge-invariant tree-level amplitudes can be constructed
with the decay widths of the unstable particles properly included in the
propagators. In these tree-level amplitudes modified vertices are used, which
contain extra gauge-restoring terms prescribed by the effective Lagrangians. We
discuss the treatment of the phenomenologically important unstable particles,
like the top-quark, the $W$- and $Z$-bosons, and the Higgs-boson, and derive
the relevant modified Feynman rules explicitly.


title: Electromagnetic Corrections to K->pi pi II - Dispersive Matching

abstract:
  We express the leading electromagnetic corrections in K-> pi pi amplitudes as
integrals over the virtual photon squared-momentum Q^2. The high Q^2 behavior
is obtained via the operator product expansion. The low Q^2 behavior is
calculated using chiral perturbation theory. We model the intermediate Q^2
region using resonance contributions in order to enforce the matching of these
two regimes. The results confirm our previous estimates that the
electromagnetic corrections provide a reasonably small shift in the delta I -
3/2 amplitude.


title: Dynamical Manifestation of the Goldstone Phenomenon at 1-loop

abstract:
  We have calculated the damping rate $\Gamma (|{\bf k}|)$ for classical
on-shell Goldstone modes of the O(2) symmetric scalar fields propagating in a
thermal medium of the broken symmetry phase taking into account the effect of
the explicit symmetry breaking. The result of the one-loop analysis can be
expanded around $\Gamma (0)$, which depends non-analytically on the parameter
of the explicit symmetry breaking, h. $\Gamma (0)$ vanishes when $h\to 0$,
demonstrating in this way the absence of the restoring force, when the
equilibrium direction of the symmetry breaking is modulated homogeneously.


title: Hoelder Inequalities and Isospin Splitting of the Quark Scalar Mesons

abstract:
  A Hoelder inequality analysis of the QCD Laplace sum-rule which probes the
non-strange (n\bar n) components of the I={0,1} (light-quark) scalar mesons
supports the methodological consistency of an effective continuum contribution
from instanton effects. This revised formulation enhances the magnitude of the
instanton contributions which split the degeneracy between the I=0 and I=1
channels. Despite this enhanced isospin splitting effect, analysis of the
Laplace and finite-energy sum-rules seems to preclude identification of
a_0(980) and a light broad sigma-resonance state as the lightest isovector and
isoscalar spin-zero $n\bar n$ mesons. This apparent decoupling of sigma [\equiv
f_0(400-1200)] and a_0(980) from the quark n\bar n scalar currents suggests
either a non-q \bar q or a dominantly s\bar s interpretation of these
resonances, and further suggests the possible identification of the f_0(980)
and a_0(1450) as the lightest I={0,1} scalar mesons containing a substantial
n\bar n component.


title: Higgs-Mediated $B^0 -> \mu^+ \mu^-$ in Minimal Supersymmetry

abstract:
  In this letter we demonstrate a new source for large flavor-changing neutral
currents within the minimal supersymmetric standard model. At moderate to large
tan(beta), it is no longer possible to diagonalize the masses of the quarks in
the same basis as their Yukawa couplings. This generates large flavor-violating
couplings of the form $\bar b_R d_L H$ and $\bar b_R s_L H$ where H is any of
the three neutral, physical Higgs bosons. These new couplings lead to rare
processes in the B system such as $B^0 -> \mu^+ \mu^-$ decay and B-Bbar mixing.
We show that the latter is anomalously suppressed, while the former is in the
experimentally interesting range. Current limits on $B^0 -> \mu^+ \mu^-$
already provide nontrivial constraints on models of moderate to large
tan(beta), with an observable signal possible at Run II of the Tevatron if m_A
< 400-600 GeV, extending to the TeV range if a proposed Run III of 30/fb were
to occur.


title: Leptogenesis and the Small-Angle MSW Solution

abstract:
  The lepton asymmetry created in the out-of-equilibrium decay of a heavy
Majorana neutrino can generate the cosmological baryon asymmetry when processed
through fast anomalous electroweak reactions. In this work I examine this
process under the following assumptions: (1) maximal nu_mu/nu_tau mixing (2)
hierarchical mass spectrum m_3 >> m_2 (3) small-angle MSW solution to the solar
neutrino deficit. Working in a basis where the charged lepton and heavy
neutrino mass matrices are diagonal, I find the following bounds on the heavy
Majorana masses M_i: (a) for a symmetric Dirac neutrino mass matrix (no other
constraints), an asymmetry compatible with BBN constraints can be obtained for
min(M_2,M_3)> 10^{11} GeV; (b) if {\em any} of the Dirac matrix elements
vanishes, successful baryogenesis can be effected for a choice of min(M_2,M_3)
as low as a few times 10^{9} GeV. The latter is compatible with reheat
requirements for supersymmetric cosmologies with sub-TeV gravitino masses.


title: New Information on B Decays to Charmless VP Final States

abstract:
  The decays of $B$ mesons to charmless final states consisting of a vector
meson ($V$) and a pseudoscalar meson ($P$) are analyzed within flavor SU(3).
Predictions are compared with new data from the CLEO Collaboration. Dominant
contributions to amplitudes and subdominant interfering terms are identified.
Evidence is found for a specific penguin amplitude (contributing, for example,
to $B^+ \to \rho^+ K^0$) at a level much higher than that implied by most
explicit models. The validity of the conclusion $\cos \gamma < 0$, obtained
through other analyses of $B \to VP$ decays, is examined here from a less
model-dependent standpoint. It is found that several processes are consistent
with $\cos \gamma < 0$ (or $\cos \alpha > 0$), and measurements are suggested
which could make this conclusion more robust.


title: On the Other Five KM Triangles

abstract:
  A comprehensive program of \cp~studies in heavy flavour decays has to go
beyond observing large \cp asymmetries in nonleptonic B decays and finding that
the sum of the three angles of the KM triangle is consistent with
180$^{\circ}$. There are many more correlations between observables encoded in
the KM matrix; those can be expressed through five KM triangles in addition to
the one usually considered. To test the completeness of the KM description one
has to obtain a highly overconstrained data set sensitive to ${\cal O}(\lambda
^2)$ effects with $\lambda = \sin \theta_C$. Those fall into two categories:
(i) Certain large angles agree to leading order only, yet differ in order
$\lambda ^2$ in a characteristic way. (ii) Two observables angles are - for
reasons specific to the KM ansatz - ${\cal O}(\lambda ^2)$ and ${\cal
O}(\lambda ^4)$ thus generating an asymmetry of a few percent and of about 0.1
%, respectively. The former can be measured in $B_s \to \psi \eta, \psi \phi$
{\em without} hadronic uncertainty, the latter in Cabibbo suppressed D decays.
The intervention of New Physics could boost these effects by an order of
magnitude. A special case is provided by $D^+ \to K_{S,L}\pi ^+$ vs. $D^- \to
K_{S,L}\pi ^-$. Finally, \cp~asymmetries involving $D^0 - \bar D^0$
oscillations could reach observable levels only due to New Physics.


title:
Can Flavor-Independent Supersymmetry Soft Phases Be the Source of All CP
  Violation?

abstract:
  Recently it has been demonstrated that large phases in softly broken
supersymmetric theories are consistent with electric dipole moment constraints,
and are motivated in some (Type I) string models. Here we consider whether
large flavor-independent soft phases may be the dominant (or only) source of
all CP violation. In this framework $\epsilon$ and $\epsilon'/\epsilon$ can be
accommodated, and the SUSY contribution to the B system mixing can be large and
dominant. An unconventional flavor structure of the squark mass matrices (with
enhanced super-CKM mixing) is required for consistency with B and K system
observables.


title: Cosmological 3-Brane Solutions

abstract:
  We analyze cosmological equations in the brane world scenario with one extra
space-like dimension. We demonstrate that the cosmological equations can be
reduced to the usual 4D Friedmann type if the bulk energy-momentum tensor is
different from zero. We then generalize these equations to the case of a brane
of finite thickness. We also demonstrate that when the bulk energy-momentum
tensor is different from zero, the extra space-like dimension can be
compactified with a single brane and show that the stability of the radius of
compactification implies standard cosmology and vice versa. For a brane of
finite thickness, we provide a solution such that the 4D Planck scale is
related to the fundamental scale by the thickness of the brane. In this case,
compactification of the extra dimension is unnecessary.


title: Restoring the sting to metric preheating

abstract:
  The relative growth of field and metric perturbations during preheating is
sensitive to initial conditions set in the preceding inflationary phase. Recent
work suggests this may protect super-Hubble metric perturbations from resonant
amplification during preheating. We show that this possibility is fragile and
sensitive to the specific form of the interactions between the inflaton and
other fields. The suppression is naturally absent in two classes of preheating
in which either (1) the vacua of the non-inflaton fields during inflation are
deformed away from the origin, or (2) the effective masses of non-inflaton
fields during inflation are small but during preheating are large. Unlike the
simple toy model of a $g^2 \phi^2 \chi^2$ coupling, most realistic particle
physics models contain these other features. Moreover, they generically lead to
both adiabatic and isocurvature modes and non-Gaussian scars on super-Hubble
scales. Large-scale coherent magnetic fields may also appear naturally.


title:
Duality and Chiral Restoration from Dilepton Production in Relativistic
  Heavy-Ion Collisions

abstract:
  We discuss the recent status in the theoretical understanding of dilepton
production in central heavy-ion reactions with the Pb-beam at the full CERN-SpS
energy of 158 AGeV. In the low-mass region ($M\le$~1 GeV) a strong broadening
of the vector meson resonances in hot and dense matter (especially for the
$\rho$ meson) entails thermal dilepton rates very reminiscent to perturbative
$q\bar q$ annihilation close to the expected phase boundary of the chiral
symmetry restoring transition. A consistent description of the experimentally
observed enhancement at both low and intermediate masses (1.5 GeV~$\le M \le$~3
GeV) in terms of thermal radiation from an expanding fireball can be obtained.


title:
$\eta'-g^*-g$ Transition Form Factor with Gluon Content Contribution
  Tested

abstract:
  We study the $\eta'-g^*-g$ transition form factor by using the $\eta'$ wave
function constrained by the experimental data on the $\eta'-\gamma^*-\gamma$
transition form factor provided by CLEO and L3 . We also take into account the
contribution of the possible gluonic content of the $\eta'$ meson.


title:
Higgs-Boson Two-Loop Contributions to Electric Dipole Moments in the
  MSSM

abstract:
  The complete set of Higgs-boson two-loop contributions to electric dipole
moments of the electron and neutron is calculated in the minimal supersymmetric
standard model. The electric dipole moments are induced by CP-violating
trilinear couplings of the `CP-odd' and charged Higgs bosons to the scalar top
and bottom quarks. Numerical estimates of the individual two-loop contributions
to electric dipole moments are given.


title: Strangeness in Hadronic Systems

abstract:
  This paper reviews different aspects of hadronic systems with strange quarks.
It reviews production, spectroscopy and decay of baryons and hypernuclei with
emphasis on recent results obtained in this field. It includes a comparison of
different systems doped with strange (or heavy) quarks, emphasizing the single
particle nature which can be observed in baryons and nuclei.


title:
Forests & Groves: Minimal Gauge Invariant Classes of Tree Diagrams in
  Gauge Theories

abstract:
  We describe the explicit construction of groves, the smallest gauge invariant
classes of tree Feynman diagrams in gauge theories


title: The High Density Parton Dynamics from Eikonal and Dipole Pictures

abstract:
  In this contribution we discuss distinct approaches for the high density QCD
(hdQCD) and the demonstration of the equivalence between the AGL approach and
the K approach is presented. Our conclusion is that the AGL equation is a good
candidate for an unitarized evolution equation at high densities in the DLA
limit.


title: Helicity skewed quark distributions of the nucleon and chiral symmetry

abstract:
  We compute the helicity skewed quark distributions $\widetilde{H}$ and
$\widetilde{E}$ in the chiral quark-soliton model of the nucleon. This model
emphasizes correctly the role of spontaneously broken chiral symmetry in
structure of nucleon. It is based on the large-N_c picture of the nucleon as a
soliton of the effective chiral lagrangian and allows to calculate the leading
twist quark- and antiquark distributions at a low normalization point. We
discuss the role of chiral symmetry in the helicity skewed quark distributions
$\widetilde{H}$ and $\widetilde{E}$. We show that generalization of soft pion
theorems, based on chiral Ward identities, leads in the region of -\xi < x <
\xi to the pion pole contribution to $\widetilde{E}$ which dominates at small
momentum transfer.


title: Search for Standard Higgs Boson at Supercolliders

abstract:
  We review the standard Higgs boson physics and the search for higgs boson at
LEP and LHC supercolliders


title: A common scheme for running NLO ep event generators

abstract:
  In this article we present a generic interface to several next-to-leading
order cross-section programs. This enables the user to implement his/her code
once and make cross-checks with different programs.


title: B => \pi \pi \ell \nu decays in a QCD relativistic potential model

abstract:
  In the framework of a QCD relativistic potential model we evaluate the form
factors describing the exclusive decay B => \pi\pi \ell \nu. The calculation is
performed in a phase space region far away from the resonances and therefore is
complementary to other decay mechanisms where the pions are produced by
intermediate particles, e.g. in the chiral approach. We give an estimate of the
contribution of the non resonant channel of the order of BR(B- => \pi+ \pi-
\ell \nu) \approx 2.2 x 10^(-4).


title: Doubly Charged Fermions Bound States,Vector Bosons Bound States

abstract:
  We consider positronium-like bound states of doubly charged fermions.We
consider also $P(CP)$-parity violation in positronium like system (including
quarkonium and lepton antilepton bound states and mesoatoms) which take place
due to $Z^0$-bosons or Higgs bosons exchange.By model independent way we
consider also vector bosons bound states in the Coulomb and Higgs potential and
have shown that in the presence of the Higgs potential effective potential
become less singular and in this case fall down on the center is absent.Vector
bosons energy levels in the magnetic field are considered. Considered magnetism
of electron gas in the finite volume.


title:
Decaying Cosmological Constant of the Inflating Branes in the
  Randall-Sundrum -Oda Model

abstract:
  We examine the issue of the cosmological constant in the $many$ $inflating$
branes scenario, extending on two recent models by I.Oda and Randall-Sundrum.
The exact solution in a closed form is found in the slow roll approximation of
the radion. Defining an effective expansion rate, which depends on the location
of each brane in the fifth dimension and demanding stability for this case we
show that each positive tension brane has a localized, decaying cosmological
constant (the opposite process applies to the negative energy branes [4]) . The
reason is that the square of the effective expansion rate enters as a source
term in the Einstein equations for the branes.Thus the brane has two scale
factors depending on time and the fifth dimnesion respectively .The brane will
roll along the fifth dimension in order to readjust its effective expansion
rate in such a way that it compensates for its internal energy changes due to
inflation and possible phase transitions.


title:
Details on the ${\cal{O}}(m_e \alpha^6)$ Positronium Hyperfine Splitting
  due to Single Photon Annihilation

abstract:
  A detailed presentation is given of the analytic calculation of the
single-photon annihilation contributions to the positronium ground state
hyperfine splitting to order $m_e\alpha^6$ in the framework of non-relativistic
effective theories. The current status of the theoretical description of the
positronium ground state hyperfine splitting is reviewed.


title: Inflating Intersecting Branes and Remarks on the Hierarchy Problem

abstract:
  We generalize solutions of Einstein's equations for intersecting branes in
higher dimensional spacetimes to the nonstatic case, modeling an expanding
universe. The relation between the Hubble rate, the brane tensions, and the
bulk cosmological constant is similar to the case of a single 3-brane in a
5-dimensional spacetime. However, because the bulk inflates as well as the
branes, this class of solutions suffers from Newton's constant tending toward
zero on the TeV brane, where the Randall-Sundrum mechanism should solve the
weak scale hierarchy problem. The strength of gravity remains constant on the
Planck brane, however.


title:
Neutralino relic density in a Universe with a non-vanishing cosmological
  constant

abstract:
  We discuss the relic density of the lightest of the supersymmetric particles
in view of new cosmological data, which favour the concept of an accelerating
Universe with a non-vanishing cosmological constant. Recent astrophysical
observations provide us with very precise values of the relevant cosmological
parameters. Certain of these parameters have direct implications on particle
physics, e.g., the value of matter density, which in conjunction with
electroweak precision data put severe constraints on the supersymmetry breaking
scale. In the context of the Constrained Minimal Supersymmetric Standard Model
(CMSSM) such limits read as: $M_{1/2} \simeq 300 \GeV - 340 \GeV$, $m_0 \simeq
80 \GeV - 130 \GeV$. Within the context of the CMSSM a way to avoid these
constraints is either to go to the large $\tan \beta$ and $\mu > 0$ region, or
make ${\tilde \tau}_R$, the next to lightest supersymmetric particle (LSP), be
almost degenerate in mass with LSP.


title:
Derivation of O(q^4) Effective Pion-Nucleon Lagrangian Within Heavy
  Baryon Chiral Perturbation Theory

abstract:
  We construct a complete list of O(q^4) terms directly within Heavy Baryon
Chiral Perturbation Theory (HBChPT) in the absence of external fields and
assuming isospin symmetry. In addition to a phase rule recently developed
(NPA646, 343, '99), a variety of algebraic identities and reparameterization
invariance, are used to ensure linear independence of the terms and their low
energy coupling constants. We first construct O(q^4) terms terms for off-shell
nucleons, and then perform the on-shell reduction, again within HBChPT. We
discuss an application of the O(q^4) terms to the evaluation of the O(q^4)
operator insertions in the "contact graph" of pion double charge exchange.


title: Susygen3, an Event Generator for Linear Colliders

abstract:
  The Monte Carlo program \texttt{SUSYGEN}, initially designed for computing
distributions and generating events for supersymmetric particle production in
$e^+e^-$ collisions, has now been upgraded to study supersymmetric processes at
linear colliders by the inclusion of beamstrahlung, beam polarization, spin
correlations and complex couplings including CP violating phases. It continues
to offer, in the new context, the possibility to study the production and decay
of supersymmetric particles within the most general minimal standard
supersymmetric model (MSSM), the minimal supergravity model (MSUGRA) or the
gauge mediated supersymmetry breaking model (GMSB), with or without assuming
R-parity conservation.


title: QED Effective Action at Finite Temperature: Two-Loop Dominance

abstract:
  We calculate the two-loop effective action of QED for arbitrary constant
electromagnetic fields at finite temperature T in the limit of T much smaller
than the electron mass. It is shown that in this regime the two-loop
contribution always exceeds the influence of the one-loop part due to the
thermal excitation of the internal photon. As an application, we study light
propagation and photon splitting in the presence of a magnetic background field
at low temperature. We furthermore discover a thermally induced contribution to
pair production in electric fields.


title:
Matter Enhanced Neutrino Oscillations with a Realistic Earth Density
  Profile

abstract:
  We have investigated matter enhanced neutrino oscillations with a
mantle-core-mantle step function and a realistic Earth matter density profile
in both a two and a three neutrino scenario. We found that the realistic Earth
matter density profile can be well approximated with the mantle-core-mantle
step function and that there could be an influence on the oscillation channel
$\nu_\mu \to \nu_\tau$ due to resonant enhancement of one of the mixing angles.


title: Quark-Loop Amplitudes for W^+- H^-+ Associated Hadroproduction

abstract:
  In this addendum to our paper entitled "W^+- H^-+ Associated Production at
the Large Hadron Collider" [Phys. Rev. D 59, 015009 (1999)], we list analytic
results for the helicity amplitudes of the partonic subprocess gg -> W^-H^+
induced by virtual quarks.


title: Top quark decays into neutral Higgs bosons and gluon in the MSSM

abstract:
  Flavour changing neutral decays of the top quark are know to be extremely
suppressed in the SM. This is especially so for the top quark decay into the SM
Higgs boson, whose rate is less than 10^-13. However, it turns out that the
decay modes t->c h, with h= h^0,H^0,A^0 any of the MSSM neutral Higgs bosons,
can be much more gifted. In particular, the rate into the lightest CP-even
Higgs boson h^0 -- which is an accessible decay mode across the whole MSSM
parameter space -- is generally higher than the decay into glue, t->c g, even
though the latter can also be considerably augmented in the MSSM. Our general
conclusion is that the Higgs channel t->c h^0 can be the ``gold-plated'' top
quark FCNC decay mode in the MSSM with rates that can reach 10^-4, i.e. already
at the visible level for both LHC and LC.


title: Diffractive Electroproduction

abstract:
  In these lectures, a simple introduction to the phenomenon of diffraction in
deep inelastic scattering and its theoretical description is given. While the
main focus is on the diffractive structure function F_2^D, some issues in
diffractive vector meson production are also discussed.


title:
Gauge Invariance of Nonlinear Landau Damping Rate of Bose Excitations in
  Quark-Gluon Plasma

abstract:
  On the basis of the approximate dynamical equations describing the behavior
of quark-gluon plasma (QGP) in the semiclassical limit and Yang-Mills equation,
the kinetic equation for longitudinal waves (plasmons) is obtained. With the
Ward identities the gauge invariance of obtained nonlinear Landau damping rate
is proved. The physical mechanisms defining nonlinear scattering of a plasmon
by QGP particles are analyzed. The problem on a connection of nonlinear Landau
damping rate of longitudinal oscillations with damping rate, obtained in the
framework of hard thermal loops approximation, is considered. It is shown that
the gauge-dependent part of nonlinear Landau damping rate for the plasmons with
zero momentum vanishes on mass-shell.


title: Non-planar massless two-loop Feynman diagrams with four on-shell legs

abstract:
  The non-planar Feynman diagram with seven massless, scalar propagators and
four on-shell legs (the crossed double box) is calculated analytically in
dimensional regularization. The non-planar diagram with six propagators is also
discussed.


title: Shadowing of Gluons at RHIC and LHC

abstract:
  We show estimates for shadowing of gluons at small values of $x$, appropriate
to RHIC and LHC experiments using a new evolution equation which takes into
account the effects of gluon recombination to all orders in gluon density. We
show that there is a significant depletion in the gluon density of large
nuclei.


title: Gravitational Particle Production and the Moduli Problem

abstract:
  A theory of gravitational production of light scalar particles during and
after inflation is investigated. We show that in the most interesting cases
where long-wavelength fluctuations of light scalar fields can be generated
during inflation, these fluctuations rather than quantum fluctuations produced
after inflation give the dominant contribution to particle production. In such
cases a simple analytical theory of particle production can be developed.
Application of our results to the theory of quantum creation of moduli fields
demonstrates that if the moduli mass is smaller than the Hubble constant then
these fields are copiously produced during inflation. This gives rise to the
cosmological moduli problem even if there is no homogeneous component of the
classical moduli field in the universe. To avoid this version of the moduli
problem it is necessary for the Hubble constant H during the last stages of
inflation and/or the reheating temperature T_R after inflation to be extremely
small.


title: Q-ball Formation through Affleck-Dine Mechanism

abstract:
  We present the full nonlinear calculation of the formation of a Q-ball
through the Affleck-Dine (AD) mechanism by numerical simulations. It is shown
that large Q-balls are actually produced by the fragmentation of the condensate
of a scalar field whose potential is very flat. We find that the typical size
of a Q-ball is determined by the most developed mode of linearized
fluctuations, and almost all the initial charges which the AD condensate
carries are absorbed into the formed Q-balls, whose sizes and the charges
depend only on the initial charge densities.


title: The Evolution of Dynamical Screening in the Parton Cacade Model

abstract:
  We determine the time evolution of the colour screening mass in high energy
nuclear collisions, as provided by the parton cascade model. Using our result,
we discuss the onset of deconfinement and the onset of quarkonium suppression
in a general, not necessarily equilibrated environment of strongly interacting
constituents.


title:
Electromagnetic self-energies of the neutral pions: Contributions from
  vector resonances

abstract:
  By employing vector meson dominance to establish the electromagnetic
interactions of hadrons, the electromagnetic self-energy of the neutral pions,
which receives the contributions from the vector resonances due to chiral
anomaly, is evaluated. This part of the electromagentic mass, which can
contribute to the mass difference of $\pi^\pm-\pi^0$, is finite and as
expected, is smaller than the contributions due to isospin symmetry breaking
and electromagnetic chiral logs corrections, however, could be compared with
the contribution from the short distance QCD.


title: On the Resonant Spin Flavor Precession of the Neutrino in the Sun

abstract:
  This work deals with the possible solution of the solar neutrino problem in
the framework of the resonant neutrino spin-flavor precession scenario. The
event rate results from the solar neutrino experiments as well as the recoil
electron energy spectrum from SuperKamiokande are used to constrain the free
parameters of the neutrino in this model. We consider two kinds of magnetic
profiles inside the sun. For both cases, a static and a twisting field are
discussed.


title: Old and New Processes of Vorton Formation

abstract:
  After a brief explanation of the concept of a vorton, quantitative estimates
of the vorton population that would be produced in various cosmic string
scenarios are reviewed. Attention is drawn to previously unconsidered
mechanisms that might give rise to much more prolific vorton formation that has
been envisaged hitherto.


title: Bi-maximal Neutrino Mixing Pattern Reexamined

abstract:
  I propose a simple extension of the bi-maximal neutrino mixing pattern,
allowing slight coupling between solar and atmospheric neutrino oscillations as
well as large CP violation. The new scenario is compatible with either the
vacuum oscillation solution or the large-angle MSW solution to the solar
neutrino


title: Comment on " a unified scheme for flavored mesons and baryons"

abstract:
  We would comment on the results of the paper "a unified scheme for flavored
mesons and baryons" (P.C.Vinodkumar, J.N.Panandya, V.M.Bannur, and
S.B.Khadkikar Eur. Phys. J. A4(1999)83), and point out some inconsistencies and
mistakes in the work for solving the Dirac equation. In terms of an example for
a single particle we investigate the reliability of the perturbative method for
computing the Coulomb energy and discuss the contribution to the wavefunction
at origin from the Coulomb potential. We conclude that the accuracy of their
numerical results needs to be reconsidered.


title: Spatial 't Hooft loop, hot QCD and Z_N domain walls

abstract:
  We show that the deconfinement phase transition in the pure Yang-Mills theory
can be characterized by the change of behaviour the spatial 't Hooft loop,
V(C). In the confining phase V has a perimeter law behaviour V(C)= exp{-mP(C)},
while in the deconfined phase it has the area law behaviour V(C)= exp{-\alpha
S(C)}. We show that the area law behaviour of the 't Hooft loop is intimately
related to the plasma-like distribution of the color charges in the hot QCD
vacuum. We also show that the "dual string tension" \alpha is equal to the
"wall tension" of the Z_N domain walls previously calculated by Bhattacharya
et.al. All these properties generalize immediately to other nonabelian theories
without fundamental charges, such as supersymmetric Yang Mills. In theories
with fundamental charges the 't Hooft loop presumably has the area law
behaviour already at zero temperature and therefore is not a good order
parameter in the strict sense.


title: Massive-Evolution Effects on Charmonium Hadroproduction

abstract:
  The fragmentation functions D_{a -> H}(x,mu^2) of a heavy hadron H, with mass
m_H, satisfy the phase-space constraint D_{a - > H}(x,mu^2)=0 for x <
m_H^2/mu^2, which is violated by the naive mu^2 evolution equations. Using
appropriately generalized mu^2 evolution equations, we reconsider the inclusive
hadroproduction of prompt J/psi mesons with high transverse momenta in the
framework of the factorization formalism of nonrelativistic quantum
chromodynamics, and determine the resulting shifts in the values of the leading
colour-octet matrix elements, which are fitted to data from the Fermilab
Tevatron.


title: Neutrino masses and mixing angles from leptoquark interactions

abstract:
  In this paper we show that the mixing between leptoquarks (LQ's) from
different $SU(2)_l$ multiplets can generate a non-trivial Majorana mass matrix
for neutrinos through one loop self energy diagrams. Such mixing can arise from
gauge invariant and renormalizable LQ-Higgs interaction terms after EW symmetry
breaking. We use the experimental indication on neutrino oscillation to find
constraints on specific combinations of LQ couplings to quark-lepton pairs and
to the SM higgs boson. These constraints are compared with the ones from
$\pi\to e\bar {\nu}_e$.


title: Psi' to J/Psi Ratio in Diffractive Photoproduction

abstract:
  We evaluate the Psi' to J/Psi ratio in diffractive photoproduction in a
light-cone framework, using charmonium wave functions extracted from
non-relativistic potential models. Contrary to current belief, we find that the
best estimate for the ratio is a factor 2 to 5 below the data. The measured
ratio constrains the distribution of the charm quark-antiquark component of the
charmonium light-cone wave function and indicates that it is more compact than
in potential models. We predict that the inelastic photoproduction ratio will
be bigger than the elastic one, and will equal that measured in
hadroproduction.


title: The Two-Loop Static Potential

abstract:
  In quantum chromodynamics (QCD), the binding energy of an infinitely heavy
quark--antiquark pair in a color singlet state can be calculated as a function
of the distance. We investigate this static potential of QCD perturbatively and
calculate the full two-loop coefficient, correcting an earlier result. Beyond
this order, the perturbative expansion breaks down.


title: Radiation Damping at a Bubble Wall

abstract:
  The first order phase transition proceeds via nucleation and growth of true
vacuum bubbles. When charged particles collide with the bubble they could
radiate electromagnetic wave. We show that, due to an energy loss of the
particles by the radiation, the damping pressure acting on the bubble wall
depends on the velocity of the wall even in a thermal equilibrium state.


title: Zero Zeros After All These (20) Years

abstract:
  We celebrate two birthdays connected with the radiation zero phenomenon.
First, a striking dip in the theoretical angular distributions of radiative
weak-boson production was discovered twenty years ago. The key experimental
interest is that this will not occur in any deviation from the standard model.
Second, the classical training of Stanley Brodsky began sixty years ago, which
was instrumental in understanding why theoretical spin-independent radiation
zeros appear in almost all Born amplitudes for the radiation of photons and
gluons and other massless gauge bosons (but rarely in physical kinematic
regions). And there are approximate zeros for massive bosons and ``Type II''
zeros that can also be studied. We discuss how the difficulties in observing
the original Mikaelian-Samuel-Sahdev zero finally may be surmounted next year.


title: Fate of Gravitons in Warped Extra Dimension

abstract:
  Interaction of bulk gravitons to Standard Model particles is examined in the
scenario of warped extra dimension. It is found that the length of the extra
dimension is of physical importance as it determines the decay widths of
graviton Kaluza-Klein modes. We show that cosmology as well as collider signals
of the Kaluza-Klein modes are very different for different choices of the
length of the fifth dimension.


title: Resonances and higher twist in polarized lepton-nucleon scattering

abstract:
  We present a detailed analysis of resonance contributions in the context of
higher twist effects in the moments of the proton spin structure function g_1.
For each of these moments, it is found that there exists a characteristic Q^2
region in which (perturbative) higher twist corrections coexist with
(non-perturbative) resonance contribution of comparable magnitude.


title:
Massive gauge bosons from the conservation of topological winding
  numbers

abstract:
  We consider a U(1) x SU(2) gauge theory on the four-dimensional manifold S^1
x S^3. If we make the assumption that only gauge transformations connected to
the identity are allowed, the winding numbers of U(1) around S^1 and of SU(2)
around S^3 become topological conserved quantities. We derive the effective
theory for non-trivial winding numbers if all distances are small compared to
the radii of the spheres. In the non-abelian case the gauge bosons become
massive.


title:
Higgs boson production in association with squark pairs in the MSSM at
  the LHC

abstract:
  We study neutral and charged Higgs boson production in association with stop
and sbottom squarks at the Large Hadron Collider (LHC), within the so-called
M-SUGRA scenario, i.e., the Supergravity (SUGRA) inspired Minimal
Supersymmetric Standard Model (MSSM). For low values of \tan\beta only the
cases \tilde{t}_1\tilde{t}_1^* H, \tilde{t}_1\tilde{t}_1^* h and
\tilde{t}_1\tilde{t}_2^* h give detectable rates while for \tan\beta greater
than 30 a variety of signals involving all Higgs bosons can be accessed, at
high collider luminosity. The dependence of these reactions on the M-SUGRA
parameters might further allow one to pin down the actual structure of the
underlying Supersymmetric (SUSY) model.


title: The CP-violating triple gluon interaction in Z -> 4 jets

abstract:
  We analyse CP-violating effects in Z -> 4 jet decays, assuming the presence
of a CP-violating effective triple gluon coupling. We discuss the influence of
this coupling on the decay width. Furthermore, we analyse different CP-odd
observables and propose strategies of a direct search for such a CP-violating
GGG coupling. The present data of LEP 1 should give significant information on
the coupling.


title: Detection of Slow Magnetic Monopole

abstract:
  Numerous and all unsuccessful attempts of experimental search for monopole in
cosmic rays and on accelerators in high energy particle collisions have been
done since the possibility of existence of a magnetic monopole has been
surveyed in 1931. Also the searches have been carried out in mica for monopole
tracks as well as for relict monopoles, entrapped by ferromagnetic inclusions
in iron-ores, moon rock and meteorites.
  A new method of search for supermassive cosmic and relict monopoles by
magnetically ordered film is considered. This approach resembles the
traditional method of nuclear emulsion chamber. Apparently the proposed method
is particularly attractive for detection of relict monopoles, released from
melting iron ore.

categories: hep-ph cond-mat.mtrl-sci hep-ex physics.ins-det


title: The Semiclassical Gluon Distribution at Next-to-Leading Order

abstract:
  The interaction of the partonic fluctuation of the virtual photon in deep
inelastic scattering with soft color fields describing the hadron is treated in
an eikonal approximation. It is known that, in this approach, the small-x limit
of the leading-order gluon distribution xg(x,Q^2) is a constant characterizing
the averaged local field strength in the target. Matching the next-to-leading
order calculation in this semiclassical framework with the one-loop parton
model result, we obtain the next-to-leading order contribution to xg(x,Q^2). It
shows a ln(1/x) enhancement at small x and is sensitive to the large distance
structure of the target. The final expression is a simple integral over
non-Abelian eikonal factors measuring the target color field. We derive a
quantitative relation between the short-distance cutoff of this integral and
the scale of the gluon distribution function in the MS-bar scheme. Our
calculation demonstrates that higher order contributions can be systematically
included in the semiclassical approach.


title: Penguin amplitudes: charming contributions

abstract:
  We briefly introduce the Wick-contraction parametrization of hadronic matrix
elements and discuss some applications to B and K physics.


title:
What Can We Learn from the Study of Single Diffractive Dissociation at
  High Energies?

abstract:
  The fundamental relations in the dynamics of single diffraction dissociation
and elastic scattering at high energies are discussed.


title: QCD at Theta ~ Pi reexamined: domain walls and spontaneous CP violation

abstract:
  We consider QCD at Theta ~ Pi with two, one and zero light flavours Nf, using
the Di Vecchia-Veneziano-Witten effective lagrangian. For Nf=2, we show that CP
is spontaneously broken at Theta = Pi for finite quark mass splittings, z=
Md/Mu \not= 1. In the z-Theta plane, there is a line of first order transitions
at Theta = Pi with two critical endpoints, z1* < z < z2*. We compute the
tension of the domain walls relating the two CP violating vacua. For Mu=Md the
tension of the family of equivalent domain walls agrees with the expression
derived by Smilga from chiral perturbation theory at next-to-leading order. For
z1* < z < z2*, z \not= 1, there is only one domain wall and a wall-some
sphaleron at Theta = Pi. At the critical points, z = z*, the domain wall fades
away, CP is restored and the transition becomes of second order. For Nf = 1, CP
is spontaneously broken only if the number of colours Nc is large and/or if the
quark is sufficiently heavy. Taking the heavy quark limit (~ Nf= 0) provides a
simple derivation of the multibranch Theta dependence of the vacuum energy of
large Nc pure Yang-Mills theory. In the large Nc limit, there are many
quasi-stable vacua with decay rate Gamma ~ exp(-N_c^4).


title: Mass corrections of vector meson distribution amplitudes

abstract:
  A model-independent way of computing the mass corrections of vector-meson
distribution amplitudes is given. The method is based on resummation of
(next-to-)leading twist local operator.


title: Exclusive meson production at COMPASS

abstract:
  We explore the feasibility to study exclusive meson production (EMP) in hard
muon-proton scattering at the COMPASS experiment. These measurements constrain
the off-forward parton distributions (OFPD's) of the proton, which are related
to the quark orbital contribution to the proton spin.


title:
5-Dimensional Assisted Inflation and the Remedy of the Fine-Tuning
  Problem

abstract:
  We extend the idea of assisted inflation to the case of power-law potentials
and demonstrate the simultaneous resolution of two major problems that plague
chaotic inflation. The implementation of the same idea in the framework of a
5-dimensional, scalar field theory leads to a model of chaotic inflation free
of fine-tuning.


title: Scalar Top Quark as the Next-to-Lightest Supersymmetric Particle

abstract:
  We study phenomenologically the scenario in which the scalar top quark is
lighter than any other standard supersymmetric partner and also lighter than
the top quark, so that it decays to the gravitino via stop -> W^+ b G. In this
case, scalar top quark events would seem to be very difficult to separate from
top quark pair production. However, we show that, even at a hadron collider, it
is possible to distinguish these two reactions. We show also that the
longitudinal polarization of the final $W^+$ gives insight into the scalar top
and wino/Higgsino mixing parameters.


title: Fitting Precision Electroweak Data with Exotic Heavy Quarks

abstract:
  The 1999 precision electroweak data from LEP and SLC persist in showing some
slight discrepancies from the assumed standard model, mostly regarding $b$ and
$c$ quarks. We show how their mixing with exotic heavy quarks could result in a
more consistent fit of all the data, including two unconventional
interpretations of the top quark.


title: Implications of Results from Z- and WW-Threshold Running

abstract:
  One year of Z- and WW-Threshold running of TESLA can provide the possibility
to measure electroweak precision observables to an extremely high accuracy. At
the Z peak O(10^9) Z bosons and about 6 10^8 b quarks can be collected. We
employ the expected uncertainties \Delta MW = 6 MeV and \Delta sin(theta_W,eff)
= 0.00001 and demonstrate in this way that very stringent consistency tests of
the Standard Model and the Minimal Supersymmetric Standard Model will be
possible. The indirect determination of the Higgs-boson mass within the
Standard Model can reach an accuracy of about 5 %. The 6 10^8 b quarks can be
used to investigate various b physics topics.


title:
Evolution equations for quark-gluon distributions in multi-color QCD and
  open spin chains

abstract:
  We study the scale dependence of the twist-3 quark-gluon parton distributions
using the observation that in the multi-color limit the corresponding QCD
evolution equations possess an additional integral of motion and turn out to be
effectively equivalent to the Schrodinger equation for integrable open
Heisenberg spin chain model. We identify the integral of motion of the spin
chain as a new quantum number that separates different components of the
twist-3 parton distributions. Each component evolves independently and its
scale dependence is governed by anomalous dimension given by the energy of the
spin magnet. To find the spectrum of the QCD induced open Heisenberg spin
magnet we develop the Bethe Ansatz technique based on the Baxter equation. The
solutions to the Baxter equation are constructed using different asymptotic
methods and their properties are studied in detail. We demonstrate that the
obtained solutions provide a good qualitative description of the spectrum of
the anomalous dimensions and reveal a number of interesting properties. We show
that the few lowest anomalous dimensions are separated from the rest of the
spectrum by a finite mass gap and estimate its value.


title:
Constraints on tan beta in the MSSM from the Upper Bound on the Mass of
  the Lightest Higgs boson

abstract:
  We investigate the possibilities for constraining tan beta within the MSSM by
combining the theoretical result for the upper bound on the lightest
Higgs-boson mass as a function of tan beta with the informations from the
direct experimental search for this particle. We discuss the commonly used
``benchmark'' scenario, in which the parameter values m_top = 175 GeV and
M_susy = 1 TeV are chosen, and analyze in detail the effects of varying the
other SUSY parameters. We furthermore study the impact of the new diagrammatic
two-loop result for mh, which leads to an increase of the upper bound on mh by
several GeV, on present and future constraints on tan beta. We suggest a slight
generalization of the ``benchmark'' scenario, such that the scenario contains
the maximal possible values for mh(tan beta) within the MSSM for fixed m_top
and M_susy. The implications of allowing values for m_top, M_susy beyond the
``benchmark'' scenario are also discussed.


title:
Flavor asymmetry of polarized antiquark distributions and semi-inclusive
  DIS

abstract:
  The $1/N_c$-expansion of QCD suggests large flavor asymmetries of the
polarized antiquark distributions in the nucleon. This is confirmed by model
calculations in the large-$N_c$ limit (chiral quark-soliton model), which give
sizable results for $\Delta\bar u (x) - \Delta\bar d (x)$ and $\Delta\bar u (x)
+ \Delta\bar d (x) - 2 \Delta \bar s (x)$. We compute the contributions of
these flavor asymmetries to the spin asymmetries in hadron production in
semi-inclusive deep-inelastic scattering. We show that the large flavor
asymmetries predicted by the chiral quark-soliton model are consistent with the
recent HERMES data for spin asymmetries in charged hadron production.


title: Nonrelativistic Quantum Hamiltonian for Lorentz Violation

abstract:
  A method is presented for deriving the nonrelativistic quantum hamiltonian of
a free massive fermion from the relativistic lagrangian of the
Lorentz-violating standard-model extension. It permits the extraction of terms
at arbitrary order in a Foldy-Wouthuysen expansion in inverse powers of the
mass. The quantum particle hamiltonian is obtained and its nonrelativistic
limit is given explicitly to third order.


title: Interaction of Magnetic Monopoles and Domain Walls

abstract:
  We study the interaction of magnetic monopoles and domain walls in a model
with SU(5)\times Z_2 symmetry by numerically evolving the field equations. We
find that the monopoles unwind and dissipate their magnetic energy on collision
with domain walls within which the full SU(5) symmetry is restored.


title:
Phi, Omega and Rho production from deconfined matter in relativistic
  heavy ion collisions at CERN SPS

abstract:
  We investigate the production of the Phi meson and the Omega baryon which
interact weakly with hot hadronic matter, and thus their spectra reflect the
early stage of the heavy ion collisions. Our analysis shows that the
hadronization temperature, T_had, and the transverse flow, v_T, of the initial
deconfined phase are strongly correlated: T_had + a * (v_T)**2 = 0.25 GeV,
where a=0.37 GeV in the Pb+Pb collision at 158 AGeV/c. When choosing
appropriate initial values of T_had and v_T from the temperature region
T_had=175 +- 15 MeV, the measured Rho meson spectra was reproduced surprisingly
well by the MICOR model. We have found weak influence of final state hadronic
interactions on the transverse hadron spectra at m_T - m_i > 0.3 GeV.