title: Evidences for a New Fundamental Interaction

abstract:
  Many evidences for the existence of the superstrong interaction are presented
and many predictions are made. The light antiquark flavor asymmetry is
calculated and shown to agree with experimental data. The formation of galaxies
is explained and their size and mass are calculated. Contents: 1) Preliminary
Ideas on Prequarks and the Number of Quarks; 2) Distribution of the Electric
Charge in Baryons, The Pion Cloud in Nucleons, The Size of Quarks, Proton's
Stability and Deep Inelastic Scattering; 3) Calculation of the Light Antiquark
Flavor Asymmetry in the Nucleons; 4) The Quark Sea Content of the Other
Baryons; 5) Quark Confinement, The Sizes of Quarks, Primon Mass and the
Generation of Quark Mass; 6) The True Potential of a Quark Pair and the 'Usual'
QCD Potential; 7) Asymptotic Freedom; 8) The Success of QCD, the Nature of
Gluons and the Number of Leptons; 9) The Supernovae Evidence for the
Superstrong Interaction; 10) The Planetary Evidence for the Superstrong
Interaction; 11) Evidences for the Superstrong Interaction from Galactic
Formation and Evolution and from the Formation of Structure; 12) The Rotation
of Spiral Galaxies; 13) General Classification of Matter; 14) The Superweak
Force; 15) The Galactic Medium; 16) The Structured State; 17) The Energies of
Baryons; 18) Generalization of the Gell-Mann-Okubo Mass Formula; 19) The
Excited States of Quarks; 20) Hadronic Molecules; 21) The Energies of Mesons;
22) The Nuclear Potential and the Stability of the Deuteron; 23) The Absence of
Nuclides with A=5 and the Instability of $Be^{8}$; 24) The Desired Unity.


title:
Critical Behavior of Hadronic Fluctuations and the Effect of Final-State
  Randomization

abstract:
  The critical behaviors of quark-hadron phase transition are explored by use
of the Ising model adapted for hadron production. Various measures involving
the fluctuations of the produced hadrons in bins of various sizes are examined
with the aim of quantifying the clustering properties that are universal
features of all critical phenomena. Some of the measures involve wavelet
analysis. Two of the measures are found to exhibit the canonical power-law
behavior near the critical temperature. The effect of final-state randomization
is studied by requiring the produced particles to take random walks in the
transverse plane. It is demonstrated that for the measures considered the
dependence on the randomization process is weak. Since temperature is not a
directly measurable variable, the average hadronic density of a portion of each
event is used as the control variable that is measurable. The event-to-event
fluctuations are taken into account in the study of the dependence of the
chosen measures on that control variable. Phenomenologically verifiable
critical behaviors are found and are proposed for use as a signature of
quark-hadron phase transition in relativistic heavy-ion collisions.


title: Dispersion Relations and Rescattering Effects in B Nonleptonic Decays

abstract:
  Recently, the final state strong interactions in nonleptonic B decays were
investigated in a formalism based on hadronic unitarity and dispersion
relations in terms of the off-shell mass squared of the $B$ meson. We consider
an heuristic derivation of the dispersion relations in the mass variables using
the reduction LSZ formalism and find a discrepancy between the spectral
function and the dispersive variable used in the recent works. The part of the
unitarity sum which describes final state interactions is shown to appear as
spectral function in a dispersion relation based on the analytic continuation
in the mass squared of one final particles. As an application, by combining
this formalism with Regge theory and SU(3) flavour symmetry we obtain
constraints on the tree and the penguin amplitudes of the decay $B^0\to
\pi^+\pi^-$.


title: CP-violating Anomalous $WW\gamma$ Couplings in e^+e^- Collisions

abstract:
  We investigate the sensitivity of future linear collider experiments to CP
violating $WW\gamma$ couplings in the process $e^{+}e^{-} \to
\nu\bar{\nu}\gamma$. We consider several sets of machine parameters: centre of
mass energies $\sqrt{s}$ = 350, 500 and 800 GeV and operating at different
luminosities. From an analysis of the differential cross-section the following
95% C.L. limits $|\tilde{\kappa}_{\gamma}| < 0.18$, $|\tilde{\lambda}_{\gamma}|
< 0.069$ are estimated to be obtained at a future 500 GeV LC with an integrated
luminosity of $125 \fb^{-1}$, a great improvement as compared to the LEP2
reach, where a senstitivity of order 2 for both couplings is found.


title:
Low energy physics and left-right symmetry. Bounds on the model
  parameters

abstract:
  In any gauge model with spontaneous symmetry breakdown the gauge boson masses
and their mixings are not independent quantities. They are interconnected
through the vacuum expectation values (VEVs) of the Higgs sector. We discuss
the low-energy experiments, namely electron-hadron, neutrino-hadron and
neutrino-electron processes in the frame of the Manifest Left-Right Symmetric
model and show the impact of these dependencies on the possible heavy gauge
boson masses and mixings. At 90 % C.L., we obtain $M_{Z_2} \geq 1475$ GeV for
phenomenologically favorable models, without $W_L-W_R$ mixing and $M_{Z_2} \geq
1205$ GeV in the other extreme case when a maximal mixing is possible. If we
consider the \lr parameters without any constraints from the Higgs sector these
limits get down to 410 GeV. Bounds on the Z_2 mixing angle as well as the W_2
mass and its mixing angle are also given.


title:
Electromagnetic self-energies of vector mesons and electromagnetic mass
  anomaly of the massive Yang-Mills particles

abstract:
  A systematic method developed by the authors to evaluate the one-loop
electromagnetic self-energies of the low-lying mesons is extended to the
calculation of the vector sector including $\rho$, $\omega$, and $\phi$-mesons.
The theoretical result of $\rho^0-\rho^\pm$ electromagnetic mass difference is
in agreement with the measurements. An interesting effect called as
electromagnetic mass anomaly of the massive Yang-Mills particles is further
discussed. There is no new parameter in this study.


title:
Are the Dirac particles of the Standard Model dynamically confined
  states in a higher-dimensional flat space?

abstract:
  Some time ago Rubakov and Shaposhnikov (RS) suggested that elementary
particles might be excitations trapped on a soliton in a flat higher
dimensional space. They gave as an example phi-4 theory in five dimensions with
a bosonic excitation on a domain wall in the fifth dimension. They also trapped
a chiral Dirac particle on the domain wall. We extend the RS field equation for
the Dirac particle to eight flat dimensions (M4 X R4) and replace the
one-dimensional domain-wall potential with a harmonic- oscillator "potential"
in the four higher dimensions. This generates bound states in approximate SU(4)
X SU(2) representations. These representations have corresponding "orbital"
times "spin" quantum numbers and bear some resemblance to the quarks and
leptons of the Standard Model. Soliton-theory suggests that the
harmonic-oscillator potential should rise only a finite amount. This will then
limit the number of generations in a natural way. It will also mean that
particles with sufficient energy might escape the well altogether and propagate
freely in the higher dimensions. It may be worth- while to search for a soliton
(instanton?) which can confine Dirac particles in the manner of the
harmonic-oscillator potential.


title: Neutrino Mixing and the Pattern of Supersymmetry Breaking

abstract:
  We study the implications of a large $\nu_\mu - \nu_\tau$ mixing angle on
lepton flavour violating radiative transitions in supersymmetric extensions of
the standard model. The transition rates are calculated to leading order in
$\epsilon$, the parameter which characterizes the flavour mixing. The
uncertainty of the predicted rates is discussed in detail. For models with
modular invariance the branching ratio $BR(\mu \to e \gamma)$ mostly exceeds
the experimental upper limit. In models with radiatively induced flavour mixing
the predicted range includes the upper limit, if the Yukawa couplings in the
lepton sector are large, as favoured by Yukawa coupling unification.


title: Collider Tests of Compact Space Dimensions Using Weak Gauge Bosons

abstract:
  We present collider tests of the recent proposal for weak-scale quantum
gravity due to new large compact space dimensions in which only the graviton
($\G$) propagates. We show that the existing high precision LEP-I $Z$-pole data
can impose non-trivial constraints on the scale of the new dimensions, via the
decay mode $Z\to f\bar{f}+\G$ ($f=q,\ell$). These bounds are comparable to
those obtained at high energy colliders and provide the first sensitive probe
of the scalar graviton. We also study $W(Z)+\G$ production and the anomalous
$WW(ZZ)$ signal from virtual $\G$-states at the Fermilab Tevatron, and compare
them with the LEP-I bound and those from LEP-II and future linear colliders.


title:
Non-conservation of Global Charges in the Brane Universe and
  Baryogenesis

abstract:
  We argue that global charges, such as baryon or lepton number, are not
conserved in theories with the Standard Model fields localized on the brane
which propagates in higher-dimensional space-time. The global-charge
non-conservation is due to quantum fluctuations of the brane surface. These
fluctuations create "baby branes" that can capture some global charges and
carry them away into the bulk of higher-dimensional space. Such processes are
exponentially suppressed at low-energies, but can be significant at high enough
temperatures or energies. These effects can lead to a new, intrinsically
high-dimensional mechanism of baryogenesis. Baryon asymmetry might be produced
due either to "evaporation" into the baby branes, or creation of the baryon
number excess in collisions of two Brane Universes. As an example we discuss a
possible cosmological scenario within the recently proposed "Brane Inflation"
framework. Inflation is driven by displaced branes which slowly fall on top of
each other. When the branes collide inflation stops and the Brane Universe
reheats. During this non-equilibrium collision baryon number can be transported
from one brane to another one. This results in the baryon number excess in our
Universe which exactly equals to the hidden "baryon number" deficit in the
other Brane Universe.


title:
QCD Rescattering and High Energy Two-Body Photodisintegration of the
  Deuteron

abstract:
  Photon absorption by a quark in one nucleon followed by its high momentum
transfer interaction with a quark in the other may produce two final-state
nucleons with high relative momentum. We sum the relevant quark rescattering
diagrams, to show that the scattering amplitude depends on a convolution
between the large angle $pn$ scattering amplitude, the hard photon-quark
interaction vertex and the low-momentum deuteron wave function. The computed
absolute values of the cross section are in reasonable agreement with the data.


title: On the Nature of the Scalar a_0(980) and f_0(980)-Mesons

abstract:
  It is presented a critical consideration of all unusual properties of the
scalar $a_0(980)$ and $f_0(980)$-mesons in the four-quark, two-quark and
molecular models. The arguments are adduced that the four-quark model is more
preferable. It is discussed the complex of experiments that could finally
resolve this issue.


title: Pion Scattering Revisited

abstract:
  Chiral Ward identities lead to consistent accounting for the sigma's width in
the linear sigma model's Feynman rules. Reanalysis of pion scattering data at
threshold imply a mass for the sigma of 600+ 200 - 100 MeV.


title:
Vacuum oscillations and excess of high energy solar neutrino events
  observed in Superkamiokande

abstract:
  The excess of solar-neutrino events above 13 MeV that has been recently
observed by Superkamiokande can be explained by the vacuum oscillation solution
to the Solar Neutrino Problem (SNP). If the boron neutrino flux is 20% smaller
than the standard solar model (SSM) prediction and the chlorine signal is
assumed 30% (or 3.4 sigmas) higher than the measured one, there exists a vacuum
oscillation solution to SNP that reproduces both the observed spectrum of the
recoil electrons, including the high energy distortion, and the other measured
neutrino rates. The most distinct signature of this solution is a semi-annual
seasonal variation of the Be7 neutrino flux with maximal amplitude. While the
temporal series of the GALLEX and Homestake signals suggest that such a
seasonal variation could be present, future detectors (BOREXINO, LENS and
probably GNO) will be able to test it.


title: Excited scalar mesons in a chiral quark model

abstract:
  First radial excitations of the isoscalar and isovector scalar mesons
f_0(400-1200), f_0(980) and a_0(980) are investigated in the framework of a
nonlocal version of a chiral quark model of the Nambu--Jona-Lasinio type. It is
shown that f_0(1370), f_J(1710) and a_0(1450) are the first radially excited
states of f_0(400-1200), f_0(980) and a_0(980) which are ground states of the
scalar meson nonet. The mesons' masses and strong decay widths are calculated.
The scalar resonance f_0(1500) is supposed to be a glueball. The status of
K_0^*(1430) is discussed.


title: Instanton Screening in the Nonperturbative Gluodynamics

abstract:
  The gluon fields screening in the stochastic vacuum of gluodynamics is
studied. The effective action is derived for the instanton interacting with
nonperturbative fields. Quantum nonperturbative effects are shown to affect
greatly the shape of instanton. The power asymptotics x^2 of the classical
"instanton's profile function" at large distances is replaced due to these
effects by Airy function asymptotics.


title: CP violation in semi-leptonic decays of the top quark within MSSM

abstract:
  We calculate the CP-violating effects in the top quark semi-leptonic three
body decays induced by the supersymmetric CP-odd phase of the top squark
trilinear soft breaking term $\arg(A_t)$. The light top squark mass is assumed
to be close to the top quark mass $m_{\tilde{t}}\sim m_t$. The CP-conserving
phase is provided by the $\chi^+$ and $\chi^0$ cut. We find that the partial
rate asymmetry is in the 0.1% level. In the most favorable parameter region the
decay rate asymmetr can reach up to 0.55%.


title: Semilocal and Electroweak Strings

abstract:
  We review a class of non-topological defects in the standard electroweak
model, and their implications. Starting with the semilocal string, which
provides a counterexample to many well known properties of topological
vortices, we discuss electroweak strings and their stability with and without
external influences such as magnetic fields. Other known properties of
electroweak strings and monopoles are described in some detail and their
potential relevance to future particle accelerator experiments and to baryon
number violating processes is considered. We also review recent progress on the
cosmology of electroweak defects and the connection with superfluid helium,
where some of the effects discussed here could possibly be tested.


title:
Pion-Kaon Scattering near the Threshold in Chiral SU(2) Perturbation
  Theory

abstract:
  In the context of chiral SU(2) perturbation theory, pion-kaon scattering is
analysed near the threshold to fourth chiral order. The scattering amplitude is
calculated both in the relativistic framework and by using an approach similar
to heavy baryon chiral perturbation theory. Both methods lead to equivalent
results. We obtain relations between threshold parameters, valid to fourth
chiral order, where all those combinations of low-energy constants which are
not associated with chiral-symmetry breaking terms drop out. The remaining
low-energy constants can be estimated using chiral SU(3) symmetry.
Unfortunately, the experimental information is not precise enough to test our
low-energy theorems.


title: Upsilon Dissociation in Quark-Gluon Plasma

abstract:
  I consider the dissociation of the upsilon meson due to absorption of a
thermal gluon. I discuss the dissociation rate in terms of the energy density,
the number density, and the temperature of the quark-gluon plasma. I compare
this to the effect due to screening.


title: Testing TeV Scale Quantum Gravity using Dijet Production at the Tevatron

abstract:
  Dijet production at the Tevatron including effects of virtual exchanges of
spin-2 Kaluza-Klein modes in theories with large extra dimensions is
considered. The experimental dijet mass and angular distribution are exploited
to obtain stringent limits ($\sim 1.2$ TeV) on the effective string scale
$M_S$.


title: Signals for R-parity-violating Supersymmetry at a 500 GeV e+ e- Collider

abstract:
  We investigate the production of charginos and neutralinos at a 500 GeV
e^+e^- collider (NLC) and study their decays to the lightest neutralino, which
then decays into multi-fermion final states through couplings which do not
conserve R-parity. These couplings are assumed to affect only the decay of the
lightest neutralino. Detailed analyses of the possible signals and backgrounds
are performed for five selected points in the parameter space.


title:
Constraining Large Extra Dimensions Using Dilepton Data from the
  Tevatron Collider

abstract:
  We use the invariant mass distribution of Drell-Yan dileptons as measured by
the CDF and D0 Collaborations at the Fermilab Tevatron and make a careful
analysis to constrain Kaluza-Klein models with large extra dimensions. The
combined data from both collaborations lead to a conservative lower bound on
the string scale M_S of about 1 TeV at 95% confidence level.


title:
Implications of Precision Electroweak Measurements for the Standard
  Model Higgs Boson

abstract:
  We summarize the status of the Standard Model with special emphasis on the
extraction of the Higgs boson mass using Bayesian inference.


title: Electroweak Symmetry Breaking and Large Extra Dimensions

abstract:
  If spacetime contains large compact extra dimensions, the fundamental mass
scale of nature, $Lambda$, may be close to the weak scale, allowing
gravitational physics to significantly modify electroweak symmetry breaking.
Operators of the form $(1/Lambda^2) |phi^* D phi|^2$ and $(1/Lambda^2) phi^* W
B phi$, where $W$ and $B$ are the SU(2) and U(1) field strengths and $phi$ is
the Higgs field, remove the precision electroweak bound on the Higgs boson mass
for values of $Lambda$ in a wide range: $4 TeV < Lambda < 11 TeV$. Within this
framework, there is no preference between a light Higgs boson, a heavy Higgs
boson, or a non-linearly realized SU(2)xU(1) symmetry beneath $Lambda$. If
there is a Higgs doublet, then operators of the form $(1/Lambda^2) phi^* phi
(G^2, F^2)$, where $G$ and $F$ are the QCD and electromagnetic field strengths,
modify the production of the Higgs boson by gluon-gluon fusion, and the decay
of the Higgs boson to 2 photons, respectively. At Run II of the Tevatron
collider, a 2-photon signal for extra dimensions will be discovered if $Lambda$
is below 2.5 (1) TeV for a Higgs boson of mass 100 (300) GeV. Furthermore, such
a signal would point to gravitational physics, rather than to new conventional
gauge theories at $Lambda$. The discovery potential of the LHC depends
sensitively on whether the gravitational amplitudes interfere constructively or
destructively with the standard model amplitudes, and ranges from $Lambda$ = 3
- 10 (2 - 4) TeV for a light (heavy) Higgs boson.


title:
Diffractive light quark jet production at hadron colliders in the
  two-gluon exchange model

abstract:
  Massless quark and antiquark jet production at large transverse momentum in
the coherent diffractive processes at hadron colliders is calculated in the
two-gluon exchange parametrization of the Pomeron model. We use the helicity
amplitude method to calculate the cross section formula. We find that for the
light quark jet production the diffractive process is related to the
differential off-diagonal gluon distribution function in the proton. We
estimate the production rate for this process at the Fermilab Tevatron by
approximating the off-diagonal gluon distribution function by the usual
diagonal gluon distribution in the proton. And we find that the cross sections
for the diffractive light quark jet production and the charm quark jet
production are in the same order of magnitude. We also use the helicity
amplitude method to calculate the diffractive charm jet production at hadron
colliders, by which we reproduce the leading logarithmic approximation result
of this process we previously calculated.


title:
Large transverse momentum direct photon production in the coherent
  diffractive processes at hadron colliders

abstract:
  Direct photon production at large transverse momentum in the coherent
diffractive processes at hadron colliders is calculated in the two-gluon
exchange model. We find that the amplitude for the production process is
related to the differential off-diagonal gluon distribution function in the
proton. We estimate the production rate at the Fermilab Tevatron by
approximately using the usual gluon distribution function. Because of the clean
signature, this process can be used to detailed study the small-x physics, and
the coherent diffractive processes at hadron colliders.


title:
Diffractive gluon jet production at hadron colliders in the two-gluon
  exchange model

abstract:
  Following our recent paper on the calculations of diffractive quark jet
production at hadron colliders, we present here the calculations of gluon jet
production at hadron colliders in the two-gluon exchange parameterization of
the Pomeron model. We use the helicity amplitude method to calculate the cross
section formula. We find that for the gluon jet production the diffractive
process is related to the differential off-diagonal gluon distribution function
in the proton. We estimate the production rate for this process at the Fermilab
Tevatron by approximating the off-diagonal gluon distribution function by the
usual diagonal gluon distribution.


title:
On the Precise Determination of the Fermi Coupling Constant from the
  Muon Lifetime

abstract:
  The determination of the Fermi coupling constant, G_F, is examined in the
light of recently calculated 2-loop QED corrections and planned experiments to
measure the muon lifetime to a level below 1ppm. The methods used in the
calculation of the QED corrections are described in detail. Sources of the
dominant theoretical and experimental uncertainties are identified. Finally the
incorporation of G_F into analyses using the full electroweak Standard Model is
discussed.


title: On technically solving an effective QCD-Hamiltonian

abstract:
  By their very nature, field-theoretical Hamiltonians are derived in momentum
representation. To solve the corresponding integro-differential equations is
more difficult than to solve the simpler differential equations in
configuration space (`Schr\"odinger equation'). For the latter many different
and very effective methods have been developed in the past. But rather than to
Fourier-transform to configuration space - which is not always easy - the
equations are solved here directly in momentum space, by using Gaussian
quadratures. Special attention is given to the case where the potential in
configuration space is linear and where the corresponding momentum-space kernel
has an almost intractable 1/(\vec k - \vec k')^4 -singularity. Its
regularization requires a certain technical effort, introducing suitable
counter terms. The method is numerically reliable and fast, faster than other
methods in the literature. It should be useful to and also applicable in other
approaches, including phenomenological Schr\"odinger-type equations.


title:
Effects of anomalous charged current dipole moments of the tau on the
  decay $\tau^-\to\nu_\tau\pi^-\pi^0$

abstract:
  We analyse the process $\tau^-\to\nu_\tau\pi^-\pi^0$ allowing for anomalous
weak charged current magnetic and electric dipole moment interactions and
determine the effects on the differential and total decay rates. Using recent
experimental data we determine the following values for the anomalous magnetic
and electric dipole moment parameters, respectively:
  $\kappa = 0.16 \pm 0.08; and |\tilde\kappa| = 0.88^{+0.25}_{-0.35}.$


title: Top Quark Physics

abstract:
  In this contribution I review the physics of top quarks at a future Linear
Collider. Main emphasis is put on the process e+ e- to ttbar close to
threshold. Different physical observables, their sensitivity to the basic
parameters and their theoretical prediction are discussed. Recent higher order
calculations are shown to have a considerable impact on a precise determination
of the top quark mass. It is pointed out how the use of mass definitions
different from the pole mass scheme become important in this respect. Continuum
top quark production above threshold is discussed briefly.


title: Jet Rates at Small x to Single-Logarithmic Accuracy

abstract:
  We present predictions of jet rates in deep inelastic scattering at small x
to leading-logarithmic order in x, including all sub-leading logarithms of
Q^2/m_R^2 where m_R is the transverse momentum scale at which jets are
resolved. We give explicit results for up to three jets, and a perturbative
expansion for multi-jet rates and jet multiplicities.


title: Oscillations of three neutrinos with all Delta m^2 approx 10^{-3} eV^2

abstract:
  Oscillations of three neutrinos with all squared mass splittings around
10^{-3} eV^2 are not firmly excluded by solar neutrino experiments. We
carefully verify that they are also perfectly compatible with atmospheric
neutrino experiments: due to accidental reasons the SuperKamiokande experiment
is rather insensitive to `solar' nu_e/\nu_mu oscillations, even if some
characteristic small effects could become visible with more statistics. This
pattern of oscillations can be excluded by new solar experiments, or cleanly
discovered at KamLand.
  We also perform a fit of the most recent atmospheric SK data within the usual
assumption that `solar' effects are negligible.


title: Testing nucleation theory in two dimensions

abstract:
  We calculate bubble-nucleation rates for (2+1)-dimensional scalar theories at
high temperature. Our approach is based on the notion of a real coarse-grained
potential. The region of applicability of our method is determined through
internal consistency criteria. We compare our results with data from lattice
simulations. Good agreement is observed when the renormalized action of the
simulated theory is known.


title: Naturalness of supersymmetric models

abstract:
  After presenting a simple procedure for testing naturalness (similar to
Bayesian inference and not more subjective than it) we show that LEP2
experiments pose a naturalness problem for `conventional' supersymmetric
models. About 95% of the parameter space of minimal supergravity MSSM is
excluded by LEP2 experiments. Moreover in this model electroweak baryogenesis,
or detectable supersymmetric corrections to mixing of K and B mesons, are
possible only in very small corners of the parameter space. The naturalness
problem is stronger in gauge mediation models, expecially with light
messengers. We recall some possible explanations (different from an improbable
numerical accident) of why supersymmetry has not (yet?) been found.


title:
Testing violations of special and general relativity through the energy
  dependence of nu_mu<--->nu_tau oscillations in the Super-Kamiokande
  atmospheric neutrino experiment

abstract:
  The atmospheric neutrino data collected by the Super-Kamiokande experiment
span about four decades in neutrino energy E, and are thus appropriate to probe
the energy dependence of the oscillation wavelength \lambda associated to
nu_mu<--->nu_tau flavor transitions, when these are assumed to explain the
data. Such dependence takes the form \lambda^{-1}\propto E^n in a wide class of
theoretical models, including ``standard'' oscillations due to neutrino mass
and mixing (n=-1), energy-independent oscillations (n=0), and violations of the
equivalence principle or of Lorentz invariance (n=1). We study first how the
theoretical zenith distributions of sub-GeV, multi-GeV, and upward-going muon
events change for different integer values of n. Then we perform a detailed
analysis of the Super-Kamiokande data by treating the energy exponent n as a
free parameter, with unconstrained scale factors for both the amplitude and the
phase of nu_mu<--->nu_tau oscillations. We find a best-fit range n=-0.9 \pm 0.4
at 90% C.L., which confirms the standard scenario (n=-1) as the dominant
oscillation mechanism, and strongly constrains possible concurrent exotic
processes (n \neq -1). In particular, we work out the interesting case of
leading standard oscillations plus subleading terms induced by violations of
special or general relativity principles, and obtain extremely stringent upper
bounds on the amplitude of such violations in the (nu_mu,nu_tau) sector.


title: An Improved Supersymmetric SU(5)

abstract:
  By supplementing minimal supersymmetric SU(5) (MSSU(5)) with a flavor ${\cal
U}(1)$ symmetry and two pairs of $\bar{15}+15$ `matter' supermultiplets, we
present an improved model which explains the charged fermion mass hierarchies
and the magnitudes of the CKM matrix elements, while avoiding the undesirable
asymptotic mass relations $m_s=m_{\mu}, m_d/m_s = m_e/m_{\mu}$. The strong
coupling $\alpha_s (M_Z)$ is predicted to be approximately 0.115, and the
proton lifetime is estimated to be about five times larger than the MSSU(5)
value. The atmospheric and solar neutrino puzzles are respectively resolved via
maximal $\nu_{\mu}-\nu_{\tau}$ and small mixing angle $\nu_e-\nu_s$ MSW
oscillations, where $\nu_s$ denotes a sterile neutrino. The ${\cal U}(1)$
symmetry ensures not only a light $\nu_s$ but also automatic `matter' parity.


title: Discovering Supersymmetry at the Tevatron in Wino LSP Scenarios

abstract:
  In supersymmetric models, Winos, partners of the SU(2) gauge bosons, may be
the lightest supersymmetric particles (LSPs). For generic parameters, charged
and neutral Winos are highly degenerate. Charged Winos travel macroscopic
distances, but can decay to neutral Winos and extremely soft leptons or pions
before reaching the muon chambers, thereby circumventing conventional trigger
requirements based on energetic decay products or muon chamber hits. However,
these charginos are detectable, and can be triggered on when produced in
association with jets. In addition, we propose a new trigger for events with a
high p_T track and low hadronic activity. For Tevatron Run II with luminosity 2
fb^-1, the proposed searches can discover Winos with masses up to 300 GeV and
explore a substantial portion of the parameter space in sequestered sector
models.


title:
Production of top quark pairs in association with a hard gluon to order
  $\alpha_s^2$

abstract:
  The production of top quark pairs accompanied by a hard gluon in $e^+e^-$
annihilation is studied including next-to-leading order corrections in the
strong coupling. At leading order, the fraction r of $t\bar{t}g$ events with
respect to all $t\bar{t}$ events is computed analytically as a function of the
minimal gluon energy. Next-to-leading order results for r are given for
center-of-mass energies of 0.5 and 1 TeV. We further calculate the differential
distribution of r with respect to several variables, including the top quark
energy and the $t\bar{t}$ invariant mass. We then investigate how our results
depend on the choice of the renormalization scheme for the top quark mass by
comparing results expressed in terms of either the pole mass or the $\msbar$
mass. Finally we estimate the sensitivity of the fraction r on the value of the
running top quark mass at a scale of 1 TeV.


title: Doublet-Triplet Splitting and Fermion Masses with Extra Dimensions

abstract:
  The pseudo-Goldstone boson mechanism for the ``doublet-triplet splitting''
problem of the grand unified theory can be naturally implemented in the
scenario with extra dimensions and branes. The two SU(6) global symmetries of
the Higgs sector are located on two separate branes while the SU(6) gauge
symmetry is in the bulk. After including several vector-like fields in the
bulk, and allowing the most general interactions with their natural strength
(including the higher dimensional ones which may be generated by gravity) which
are consistent with the geometry, a realistic pattern of the Standard Model
fermion masses and mixings can be naturally obtained without any flavor
symmetry. Neutrino masses and mixings required for the solar and atmospheric
neutrino problems can also be accommodated. The geometry of extra dimensions
and branes provides another way to realize the absence of certain interactions
(as required in the pseudo-Goldstone boson mechanism) or the smallness of some
couplings (e.g., the Yukawa couplings between the fermions and the Higgs
bosons), in addition to the usual symmetry arguments.


title:
A New Technique for Determining the Properties of a Narrow $s$-channel
  Resonance at a Muon Collider

abstract:
  We explore an alternative to the usual procedure of scanning for determining
the properties of a narrow $s$-channel resonance. By varying the beam energy
resolution while sitting on the resonance peak, the width and branching ratios
of the resonance can be determined. The statistical accuracy achieved is
superior to that of the usual scan procedure in the case of a light SM-like
Higgs boson with $\mh>130\gev$ or for the lightest pseudogoldstone boson of a
strong electroweak breaking model if $\mpzero>150\gev$.


title: Two-Photon Production of Four-Quark States Up to the $J/\psi$ Energy

abstract:
  Evidence for an explicitly exotic state with isospin 2 and spin-parity 2^+
near the $\rho\rho$ threshold and nontrivial complementary indications of the
unusual quark composition of the $f_0(980)$ and $a_0(980)$ states obtained from
the reactions of two-photon formation of neutral meson resonances are
discussed, together with puzzling phenomena in the channels
$\gamma\gamma\to\rho^0\phi$ and $\gamma\gamma\to\rho^0\rho^0$ at high energies.


title: Hard Diffraction in Vector Meson Production at HERA

abstract:
  A review is presented of diffractive vector meson production at HERA, with
stress on the investigation of ``hard'' features and comparisons with
theoretical predictions based on perturbative QCD approaches.


title:
Non factorizable $O(\alpha\alpha_s)$ corrections to the process $Z\to
  b\bar{b}$

abstract:
  We evaluate non factorizable $O(\alpha\alpha_s)$ corrections to the process
$Z\to b\bar{b}$ due to the virtual t-quark. All two-loop vertex diagrams with
$W$'s and charged ghosts $\Phi$'s are included. They are evaluated in the large
top-mass expansion up to the $10^{th}$ order. Gluon Bremsstrahlung is taken
into account by integrating over the whole phase space. All calculations,
including Bremsstrahlung, are done in dimensional regularization. The expansion
coefficients of the large mass expansion are given in closed form. Their
expansion in $y=m_Z^2/4m_W^2$ is in agreement with the coefficients up to
$O(m_W^6/m_t^6)$ as given by Harlander et al.


title:
Is neutrino decay really ruled out as a solution to the atmospheric
  neutrino problem from Super-Kamiokande data?

abstract:
  In this paper we do a detailed $\chi^2$-analysis of the 848 days of
Super-Kamiokande(SK) atmospheric neutrino data under the assumptions of
$\nu_\mu - \nu_\tau$ oscillation and neutrino decay. For the latter we take the
most general case of neutrinos with non-zero mixing and consider the
possibilities of the unstable component in $\nu_\mu$ decaying to a state with
which it mixes (scenario (a)) and to a sterile state with which it does not mix
(scenario (b)). In the first case $\Delta m^2$ (mass squared difference between
the two mass states which mix) has to be $>$ 0.1 $eV^2$ from constraints on $K$
decays while for the second case $\Delta m^2$ can be unconstrained. For case
(a) $\Delta m^2$ does not enter the $\chi^2$-analysis while in case (b) it
enters the $\chi^2$-analysis as an independent parameter. In scenario (a) there
is \dm averaged oscillation in addition to decay and this gets ruled out at
100.0% C.L. by the latest SK data. Scenario (b) on the other hand gives a
reasonably good fit to the data for \dm $\sim 0.001 ~eV^2$.


title: A Feynman Diagram Analyser DIANA

abstract:
  A C-program DIANA (DIagram ANAlyser) for the automatic Feynman diagram
evaluation is presented. It consists of two parts: the analyzer of diagrams and
the interpreter of a special text manipulating language. This language is used
to create a source code for analytical or numerical evaluations and to keep the
control of the process in general.


title: Oscillation Solutions to Solar Neutrino Problem

abstract:
  The current status of oscillation solutions to the Solar Neutrino Problem is
reviewed. Four oscillation solutions are discussed in the light of 708d
Superkamiokande data: MSW, Just-So VO, VO with Energy-Independent Suppression
(EIS) and Resonant-Spin-Flavor-Precession (RSFP). Only EIS VO is strongly
disfavoured by the global rates, mostly due to the Homestake data. Vacuum
oscillations give an interesting solution which explains high-energy excess of
events observed by Superkamiokande and predicts {\em semi-annual} seasonal
variation of $Be$-neutrino flux. There are indications to these variations in
the GALLEX and Homestake data. No direct evidence for oscillation is found yet.


title: Supersymmetry Searches at e^+e^- Linear Colliders

abstract:
  The physics potential of discovering and exploring supersymmetry at future
e^+e^- linear colliders is reviewed. Such colliders are planned to start to
operate at a center-of-mass energy of 500 GeV to 800 GeV, with a final energy
of about 2 TeV expected. They are ideal facilities for the discovery of
supersymmetric particles. High precision measurements of their properties and
interactions will help to uncover the mechanism of supersymmetry breaking and
will allow for tests of grand unification scenarios.


title: Stabilization of Embedded Defects by Plasma Effects

abstract:
  In models in which some of the scalar field are charged and some uncharged,
interactions with a finite temperature plasma will lead to corrections to the
effective potential of the charged fields which may stabilize embedded defects
made up of uncharged fields. In these models embedded defects, solutions of the
field equations which are unstable at zero temperature, may thus be stable in
the early Universe, and may then play an important role in cosmology. Two
prototypical examples are the pion string in the theory of strong interactions,
and the electroweak Z-string in the standard electroweak theory.


title: Collider Signatures from the Brane World

abstract:
  We discuss some collider signatures of the brane world. In addition to the
usual bulk (closed string) fields and brane (open string) fields in the Type I
string picture, there are closed string fields, namely, twisted modes, which
are not confined on the branes but nonetheless are localized in the extra
compactified dimensions. While the coupling of the Standard Model (brane)
fields with a bulk mode (such as the graviton) is suppressed by powers of the
Planck mass, their coupling to a twisted mode is suppressed only by powers of
the string scale M_s, which can be as low as a few TeV. This means these
localized twisted fields can have important observable effects in the TeV
range, including resonances in dijet invariant mass distributions in \bar p p,
pp \to jets + X. Given the current lower bound on the fundamental
higher-dimensional Planck scale, the experimental effects of these twisted
fields may turn out to be larger than the effects of virtual and real KK
gravity modes. The collider signatures of anomalous U(1) gauge symmetries as
well as other phenomenological implications of the brane world are also
discussed.


title:
Composite photon and W^\pm, Z^0 vector bosons from a top-condensation
  model at fixed v = 247 GeV

abstract:
  Starting from the historical Fermi four-fermion low-energy effective
electroweak interactions Lagrangian for the third generation of quarks,
augmented by an NJL type interaction responsible for dynamical symmetry
breaking and heavy quark mass generation, and fixing the scalar (Higgs) field
v.e.v. at v = 247 GeV, we show that: (1) heavy quark bound states Q\bar Q with
quantum numbers of the W^\pm bosons exist for arbitrarily weak (positive)
vector coupling G_F, so long as the quark mass is sufficiently large; (2) a
massive composite neutral vector boson (Z^0) appears; (3) a massless composite
parity-conserving neutral vector boson (\gamma) appears, the composite
Higgs-Kibble ghosts decouple from the quarks and other particles, the
longitudinal components of the vector boson propagators vanish, as G_F \to
G_F^expt = 1/(\sqrt2 v^2), which also implies that the cutoff \Lambda \to
\infty. Thus, the Fermi interaction model is equivalent to a locally gauge
invariant theory but with definite values of coupling constants and masses. The
model discussed here was chosen for illustrative purposes and is not equivalent
to the Standard Model.


title:
Next-to-Leading Order Description of Nucleon Structure Function In Valon
  Model

abstract:
  We have improved and examined the applicability of the valon model where the
structure of any hadron is determined by the structure of its constituent
quarks. Nucleon structure functions are calculated within this model in the
Next-to-Leading order. The results compare well with the experimental data. The
model handles the bound state problem and the calculations show a flat or
almost flat behavior for $F_{2}$ which sets in at some region of $x\leq
10^{-5}$at fixed $Q^{2}$. The emergence of this behavior is a consequence of
the model and was not put in a priori as a theoretical guess. It seems that
such a flatness can be inferred from HERA data, although, not completely
confirmed yet. A set of parton distributions are given and their evolutions are
tested. Some qualitative implications of the model for the spin structure of
the proton is discussed.


title: About one long-range contribution to K+ -> pi+ l+ l- decays

abstract:
  We investigate the mechanism of K+ -> pi+ l+ l- (l= e, mu) decays in which a
virtual photon is emitted either from the incoming K+ or the outgoing pi+. We
point out some inconsistencies with and between two previous calculations,
discuss the possible experimental inputs, and estimate the branching fractions.
This mechanism alone fails to explain the existing experimental data by more
than one order-of-magnitude. But it may show itself by its interference with
the leading long-range mechanism dominated by the a_1^+ and rho^0 mesons.


title: Diphoton signals for Low Scale Gravity in Extra Dimensions

abstract:
  Gravity can become strong at the TeV scale in the theory of extra dimensions.
An effective Lagrangian can be used to describe the gravitational interactions
below a cut-off scale. In this work, we study the diphoton production in
$\gamma\gamma$, $p\bar p$, and $e^+ e^-$ collisions in the model of low scale
gravity. Since in the standard model photon-photon scattering only occurs via
box diagrams, the cross section is highly suppressed. Thus, photon-photon
scattering opens an interesting opportunity for studying the new gravity
interaction, which allows tree-level photon couplings. In addition, we also
examine the diphoton production at hadronic and $e^+ e^-$ colliders. We derive
the limits on the cut-off scale from the available diphoton data and also
estimate the sensitivity reach in Run II at the Tevaton and at the future
linear $e^+ e^-$ colliders.


title: Cosmological Constraints on Theories with Large Extra Dimensions

abstract:
  In theories with large extra dimensions, constraints from cosmology lead to
non-trivial lower bounds on the fundamental scale M_F, corresponding to upper
bounds on the radii of the compact extra dimensions. These constraints are
especially relevant to the case of two extra dimensions, since only if M_F is
10 TeV or less do deviations from the standard gravitational force law become
evident at distances accessible to planned sub-mm gravity experiments. By
examining the graviton decay contribution to the cosmic diffuse gamma
radiation, we derive, for the case of two extra dimensions, a conservative
bound M_F > 110 TeV, corresponding to r_2 < 5.1 times 10^-5 mm, well beyond the
reach of these experiments. We also consider the constraint coming from
graviton overclosure of the universe and derive an independent bound M_F > 6.5
h^(-1/2) TeV, or r_2 < .015 h mm.


title: Analysis of Narrow s-channel Resonances at Lepton Colliders

abstract:
  The procedures for studying a single narrow s-channel resonance or nearly
degenerate resonances at a lepton collider, especially a muon collider, are
discussed. In particular, we examine four methods for determining the
parameters of a narrow s-channel resonance: scanning the resonance, measuring
the convoluted cross section, measuring the Breit-Wigner area, and sitting on
the resonance while varying the beam energy resolution. This latter procedure
is new and appears to be potentially very powerful. Our focus is on computing
the errors in resonance parameters resulting from uncertainty in the beam
energy spread. Means for minimizing these errors are discussed. The discussion
is applied to the examples of a light SM-Higgs, of the lightest pseudogoldstone
boson of strong electroweak breaking, and of the two spin-1 resonances of the
Degenerate BESS model (assuming that the beam energy spread is less than their
mass splitting). We also examine the most effective procedures for nearly
degenerate resonances, and apply these to the case of Degenerate BESS
resonances with mass splitting of order the beam energy spread.


title: Enhancement of disoriented chiral condensate domains with friction

abstract:
  We investigate the effect of friction on domain formation in disoriented
chiral condensate. Including a friction term, we solve the equation of motion
of the linear sigma model fields, in the Hartree approximation. With
boost-invariance and cylinderical symmetry, irrespective of friction, on
average, we donot find any indication of domain like formation with quenched
initial condition. However, with or without friction, some events can be found
with large instabilities, indicating possible DCC domain formation in those
events. With friction time scale during which instabilities grows increases.
Correspondingly, with friction, it is possible to obtain large sized domains in
some particular events.


title: Simulating hot Abelian gauge dynamics

abstract:
  The time evolution of soft modes in a quantum gauge field theory is to first
approximation classical, but the equations of motion are non-local. We show how
they can be written in a local and Hamiltonian way in an Abelian theory, and
that this formulation is particularly suitable for numerical simulations. This
makes it possible to simulate numerically non-equilibrium processes such as the
phase transition in the Abelian Higgs model and and to study, for instance,
bubble nucleation and defect formation. Such simulations would also help to
understand phase transitions in more complicated gauge theories. Moreover, we
show that the existing analytical results for the time-evolution in a
pure-gauge theory correspond to a special class of initial conditions and that
different initial conditions can lead to qualitatively different behavior. We
compare the results of the simulations to analytical calculations and find an
excellent agreement.


title: CP Violation in B Decays

abstract:
  In the near future, we will have the first significant experimental
measurements of CP violation in B decays. These measurements will easily test
crucial questions such as whether the Standard Model Kobayashi-Maskawa phase
plays a dominant role in CP violation or whether CP is an approximate symmetry
in nature. We explain the different types of CP violation in B decays, and the
usefulness of measuring them. We use the same formalism to describe the epsilon
and epsilon(prime) parameters of the neutral K system and to explain the terms
direct and indirect CP violation. We present the Standard Model predictions for
the various asymmetries. We argue that certain CP asymmetries in B decays are
subject to a very clean theoretical interpretation in terms of fundamental
Lagrangian parameters. Within the Standard Model, these asymmetries will
provide very accurate measurements of the CKM parameters. In case that
deviations from the Standard Model predictions will be found, there is enough
information to understand the nature of New Physics that is required to explain
them. We demonstrate this statement by analyzing the impact of various
Supersymmetric flavor models on CP violation.


title: On Possible Modifications of Gravitation in the (sub)millimeter range

abstract:
  I discuss possible modifications of gravitation at short distances in string
theories with large internal dimensions and low string scale. The modifications
are due to the change of Newton's law in the presence of (sub)millimeter-size
transverse dimensions, or due to the existence of light scalars with masses as
small as 10^{-3} eV, related to the mechanism of supersymmetry breaking,
mediating new Yukawa-type forces with strength comparable to gravity. These
modifications are testable in "tabletop" experiments that measure gravity at
such short distances.


title: SUSY-QCD Effect on Top-Charm Associated Production at Linear Collider

abstract:
  We evaluate the contribution of SUSY-QCD to top-charm associated production
at next generation linear colliders. Our results show that the production cross
section of the process $e^+e^-\to t\bar c{or}\bar t c$ could be as large as 0.1
fb, which is larger than the prediction of the SM by a factor of $10^8$.


title: Multijet events and parton showers

abstract:
  We propose a general approach for the description of multijet events in the
framework of QCD event generators. We introduce a new algorithm to match parton
showers and arbitrary matrix elements for the production of any number of jets
via the strong or electroweak interaction. We developped a new parton cascade
code capable to deal with multijet events at LEP energies and beyond.


title:
Dispersion relations and the $\Delta$ contributions into the amplitudes
  $M_{1+}^{3/2},E_{1+}^{3/2}$ from new VPI partial-wave analysis of pion
  photoproduction

abstract:
  Within fixed-t dispersion relations the results of new VPI partial-wave
analysis for the multipole amplitudes $M_{1+}^{3/2},E_{1+}^{3/2}$ are
successfuly described, and the resonance and nonresonance contributions into
these amplitudes are separated in correspondence with the interpretation on the
language of diagram approach, dynamical models and effective Lagrangian
approach. The amplitudes $A_p^{3/2}$ and $A_p^{1/2}$ corresponding to the
$\Delta$ contributions into $M_{1+}^{3/2},E_{1+}^{3/2}$ are obtained. They are
in better agreement with quark model predictions than the amplitudes extracted
without subtraction of the nonresonance contributions in
$M_{1+}^{3/2},E_{1+}^{3/2}$. The obtained value of the ratio $E2/M1$ for the
$\gamma N \to P_{33}(1232)$ transition is: $E2/M1=-0.022\pm 0.004$.


title: CP Phases in Supersymmetric Tri-lepton Signals at the Tevatron

abstract:
  We have analyzed the supersymmetric tri-lepton signals for sparticle searches
at the Tevatron in the minimal supersymmetric standard model with general CP
phases without generational mixing. The CP phases may affect very strongly the
chargino and neutralino mass spectrums and
$\sigma(p\bar{p}\to\tilde{\chi}^-_1\tilde{\chi}^0_2)$ as well as ${\cal
B}(\tilde{\chi}^-_1\to\tilde{\chi}^0_1\ell^-\nu)$ and ${\cal
B}(\tilde{\chi}^0_2\to\tilde{\chi}^0_1\ell^+\ell^-)$. Even under the stringent
constraints from the electron electric dipole moment the CP phases can lead to
a minimum of the tri-lepton event rate for their non-trivial values.


title: Total $\gamma^*$ p Cross Section

abstract:
  This paper shows that the approach based on Gribov's ideas for the
photon-proton interaction, is able to describe the experimental data over a
wide range of photon virtualities $Q^2 = 0 - 100 GeV^2$ and energies $\sqrt{s}
= W = 3 - 300 GeV$. A simple model is suggested which provides a quantitative
way of describing the matching between short and long distances (between "soft"
and "hard" processes) in photon-proton interaction at high energy. The main
results of our analysis are: (i) the values of the separation parameters
differentiating the "soft" and "hard" interactions are determined; (ii) the
additive quark model can be used to calculate the "soft" contribution to the
photon - proton interaction; (iii) a good description of the ratio
$\sigma_L/\sigma_T$ is obtained ; and (iv) a considerable contribution of the
"soft" process at large $Q^2$, and of "hard" processes at small $Q^2$ was
found.


title:
Analytical results for $e^+e^-\to t\bar t$ and $\gamma\gamma\to t\bar t$
  observables near the threshold up to the next-to-next-to-leading order of
  NRQCD

abstract:
  We present an analytical description of top-antitop pair production near the
threshold in $e^+e^-$ annihilation and $\g\g$ collisions. A set of basic
observables considered includes the total cross sections, forward-backward
asymmetry and top quark polarization. The threshold effects relevant for the
basic observables are described by three universal functions related to S wave
production, P wave production and S-P interference. These functions are
computed analytically up to the next-to-next-to-leading order of NRQCD. The
total $e^+e^-\to t\bar t$ cross section near the threshold is obtained in the
next-to-next-to-leading order in the closed form including the contribution due
to the axial coupling of top quark and mediated by the Z-boson. The effects of
the running of the strong coupling constant and of the finite top quark width
are taken into account analytically for the P wave production and S-P wave
interference.


title: Can Neutrinos be Degenerate in Mass?

abstract:
  We reconsider the possibility that the masses of the three light neutrinos of
the Standard Model might be almost degenerate and close to the present upper
limits from Tritium beta decay and cosmology. In such a scenario, the
cancellations required by the latest upper limit on neutrinoless double-beta
decay enforce near-maximal mixing that may be compatible only with the
vacuum-oscillation scenario for solar neutrinos. We argue that the mixing
angles yielded by degenerate neutrino mass-matrix textures are not in general
stable under small perturbations. We evaluate within the MSSM the
generation-dependent one-loop renormalization of neutrino mass-matrix textures
that yielded degenerate masses and large mixing at the tree level. We find that
m_{nu_e} > m_{nu_mu} > m_{nu_tau} after renormalization, excluding MSW effects
on solar neutrinos. We verify that bimaximal mixing is not stable, and show
that the renormalized masses and mixing angles are not compatible with all the
experimental constraints, even for tanbeta as low as unity. These results hold
whether the neutrino masses are generated by a see-saw mechanism with heavy
neutrinos weighing approx. 10^{13} GeV or by non-renormalizable interactions at
a scale approx. 10^5 GeV. We also comment on the corresponding renormalization
effects in the minimal Standard Model, in which m_{nu_e} < m_{nu_mu} <
m_{nu_tau}. Although a solar MSW effect is now possible, the perturbed neutrino
masses and mixings are still not compatible with atmospheric- and
solar-neutrino data.


title: Odderon-Pomeron Interference

abstract:
  We show that the asymmetry in the fractional energy of charm versus anticharm
jets produced in high energy diffractive photoproduction is sensitive to the
interference of the Odderon $(C = -)$ and Pomeron $(C = +)$ exchange amplitudes
in QCD. We predict the dynamical shape of the asymmetry in a simple model and
estimate its magnitude to be of the order 15% using an Odderon coupling to the
proton which saturates constraints from proton-proton vs. proton-antiproton
elastic scattering. Measurements of this asymmetry at HERA could provide firm
experimental evidence for the presence of Odderon exchange in the high energy
limit of strong interactions.


title:
Majorana Neutrino Masses from Neutrinoless Double Beta Decay and
  Cosmology

abstract:
  When three Majorana neutrinos describe the solar and atmospheric neutrino
data via oscillations, a nonzero measurement of neutrinoless double beta
($0\nu\beta\beta$) decay can determine the sum of neutrino masses $\sum m_\nu$
if the solar solution has small-angle mixing, and place a lower bound on $\sum
m_\nu$ for large-angle solar mixing. If in addition a nonzero $\sum m_\nu$ is
deduced from cosmology, the neutrino mass spectrum may be uniquely specified
for some ranges of neutrino parameters. For $\sum m_\nu > 0.75$ eV, the
small-angle solar solution is excluded by the current upper limit on
neutrinoless double beta decay. In models with maximal solar mixing the $CP$
phases of the neutrinos may be strongly constrained by stringent upper bounds
on $0\nu\beta\beta$ decay.


title:
Supersymmetry Reach of the Tevatron via Trilepton, Like-Sign Dilepton
  and Dilepton plus Tau Jet Signatures

abstract:
  We determine the Tevatron's reach in supersymmetric parameter space in
trilepton, like-sign dilepton, and two lepton one tau-jet channels. We
critically study the standard model background processes. We find larger
backgrounds and, hence, significantly smaller reach regions than recent
analyses. We identify the major cause of the background discrepancy. We improve
signal-to-noise by introducing an invariant mass cut which takes advantage of a
sharp edge in the signal dilepton invariant mass distribution. Also, we
independently vary the cuts at each point in SUSY parameter space to determine
the set which yields the maximal reach. We find that this cut optimization can
significantly enhance the Tevatron reach.


title:
Effects of supersymmetric CP violating phases on B \to X_s l^+ l^- and
  \epsilon_K

abstract:
  We consider effects of CP violating phases in \mu and A_t parameters in the
effective supersymmetric standard model on B\to X_s l^+ l^- and \epsilon_K.
Scanning over the MSSM parameter space with experimental constraints including
edm constraints from Chang-Keung-Pilaftsis (CKP) mechanism, we find that the
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 Br(B \to X_s \gamma) is
distinctly different from the minimal supergravity scenario. Also we find 1
\lesssim \epsilon_K / \epsilon_K^{SM} \lesssim 1.4, and fully supersymmetric CP
violation in K_L \to \pi \pi is not possible. Namely, |\epsilon_K^{\rm SUSY}|
\lesssim O(10^{-5}) if the phases of \mu and A_t are the sole origin of CP
violation.


title:
Hybrid Inflation in Supergravity with $(SU(1,1)/U(1)) ^{m}$ K$%
  \ddot{a}$hler Manifolds

abstract:
  In the presence of fields without superpotential but with large vevs through
D-terms the mass-squared of the inflaton in the context of supergravity hybrid
inflation receives positive contributions which could cancel the possibly
negative K$\ddot{a}$hler potential ones. The mechanism is demonstrated using
K$\ddot{a}$hler potentials associated with products of $SU(1,1)/U(1)$
K$\ddot{a}$hler manifolds. In a particularly simple model of this type all
supergravity corrections to the F-term potential turn out to be proportional to
the inflaton mass allowing even for an essentially completely flat inflationary
potential. The model also allows for a detectable gravitational wave
contribution to the microwave background anisotropy. Its initial conditions are
quite natural largely due to a built in mechanism for a first stage of
``chaotic'' D-term inflation.


title:
Neutrino oscillations and the effect of the finite lifetime of the
  neutrino source

abstract:
  We consider a neutrino source at rest and discuss a condition for the
existence of neutrino oscillations which derives from the finite lifetime
$\tau_S$ of the neutrino source particle. This condition is present if the
neutrino source is a free particle such that its wave function is
non-stationary. For a Gaussian wave function and with some simplifying
assumptions, we study the modification of the usual oscillation probability
stemming from $\tau_S$. In the present accelerator experiments the effect of
$\tau_S$ can be neglected. We discuss some experimental situations where the
source lifetime becomes relevant in the oscillation formula.


title: The Light Quark Sector, CP Violation, and the Unitarity Triangle

abstract:
  In view of the observed strong hierarchy of quark masses, we propose a new
description of flavor mixing which is particularly suited for models of quark
mass matrices based on flavor symmetries. The necessary and sufficient
conditions for CP violation are clarified. The emergence of CP violation is
primarily linked to a large phase difference (near 90^{\circ}) in the light
quark sector. The unitarity triangle is determined by the mass ratios of the
light quarks. We conclude that the unitarity triangle should be close or
identical to a rectangular triangle, and CP violation is maximal in this sense.
Instructive predictions for flavor mixing angles and CP-violating parameters,
which can directly be confronted with the forthcoming data from B-meson
factories, are obtained from a specific texture of quark mass matrices.


title: Production of Neutral Higgs-Boson Pairs at LHC

abstract:
  The reconstruction of the Higgs potential in the Standard Model or
supersymmetric theories demands the measurement of the trilinear Higgs
couplings. These couplings affect the multiple production of Higgs bosons at
high energy colliders. We present a systematic overview of the cross sections
for the production of pairs of (light) neutral Higgs bosons at the LHC. The
analysis is carried out for the Standard Model and its minimal supersymmetric
extension.


title:
Nonpartonic components in the nucleon structure functions at small Q^2
  in a broad range of x

abstract:
  We construct a simple two-phase model of the nucleon structure functions
valid for both small and large Q^2 and in the broad range of Bjorken x. The
model incorporates hadron dominance at small x and Q^2 and parton model at
large Q^2. The VDM contribution is modified for small fluctuation times of the
hadronic state of the photon. With two free parameters we describe SLAC, CERN
NMC, Fermilab E665 and CERN BCDMS data for both proton and deuteron structure
functions. Our model explains some phenomenological higher-twist effects
extracted from earlier analyses. A good description of the NMC F_2^p(x) -
F_2^n(x) data is obtained in contrast to other models in the literature. We
predict faster vanishing of the partonic component at low Q^2 than previously
expected and strong Q^2 dependence of the Gottfried Sum Rule below Q^2 ~ 4
GeV^2.


title:
The Effect of low Momentum Quantum Fluctuations on a Coherent Field
  Structure

abstract:
  In the present work the evolution of a coherent field structure of the
Sine-Gordon equation under quantum fluctuations is studied. The basic equations
are derived from the coherent state approximation to the functional
Schr\"odinger equation for the field. These equations are solved asymptotically
and numerically for three physical situations. The first is the study of the
nonlinear mechanism responsible for the quantum stability of the soliton in the
presence of low momentum fluctuations. The second considers the scattering of a
wave by the Soliton. Finally the third problem considered is the collision of
Solitons and the stability of a breather.
  It is shown that the complete integrability of the Sine-Gordon equation
precludes fusion and splitting processes in this simplified model.
  The approximate results obtained are non-perturbative in nature, and are
valid for the full nonlinear interaction in the limit of low momentum
fluctuations. It is also found that these approximate results are in good
agreement with full numerical solutions of the governing equations. This
suggests that a similar approach could be used for the baby Skyrme model, which
is not completely integrable. In this case the higher space dimensionality and
the internal degrees of freedom which prevent the integrability will be
responsable for fusion and splitting processes. This work provides a starting
point in the numerical solution of the full quantum problem of the interaction
of the field with a fluctuation.


title:
Fixed-t subtracted dispersion relations for Compton scattering off the
  nucleon

abstract:
  We present fixed-$t$ subtracted dispersion relations for Compton scattering
off the nucleon at energies $E_\gamma \leq$ 500 MeV, as a formalism to extract
the nucleon polarizabilities with a minimum of model dependence. The subtracted
dispersion integrals are mainly saturated by $\pi N$ intermediate states in the
$s$-channel $\gamma N \to \pi N \to \gamma N$ and $\pi \pi$ intermediate states
in the $t$-channel $\gamma \gamma \to \pi \pi \to N \bar N$. For the subprocess
$\gamma \gamma \to \pi \pi$, we construct a unitarized amplitude and find a
good description of the available data. We show results for Compton scattering
using the subtracted dispersion relations and display the sensitivity on the
scalar polarizability difference $\alpha - \beta$ and the backward spin
polarizability $\gamma_\pi$, which enter directly as fit parameters in the
present formalism.


title: The MSW Effect in Quantum Field Theory

abstract:
  We show in detail the general relationship between the Schr\"{o}dinger
equation approach to calculating the MSW effect and the quantum field
theoretical S-matrix approach. We show the precise form a generic neutrino
propagator must have to allow a physically meaningful ``oscillation
probability'' to be decoupled from neutrino production fluxes and detection
cross-sections, and explicitly list the conditions---not realized in cases of
current experimental interest---in which the field theory approach would be
useful.


title: Energy-Scale Dependence of the Lepton-Flavor-Mixing Matrix

abstract:
  We study an energy-scale dependence of the lepton-flavor-mixing matrix in the
minimal supersymmetric standard model with the effective dimension-five
operators which give the masses of neutrinos. We analyze the renormalization
group equations of kappa_{ij}s which are coefficients of these effective
operators under the approximation to neglect the corrections of O(\kappa^2). As
a consequence, we find that all phases in $\kappa$ do not depend on the
energy-scale, and that only n_g-1 (n_g: generation number) real independent
parameters in the lepton-flavor-mixing matrix depend on the energy-scale.


title: Prediction for $\alpha_3(M_z)$ in a string-inspired model

abstract:
  We apply the Renormalisation Group Evolution (RGE) to analyze the
phenomenological implications of an extended supersymmetric model, for the
value of the unification scale and the strong coupling at the electroweak
scale. The model we consider is predicted to exist in Calabi-Yau string
compactifications with Wilson line mechanism for $E_6$ symmetry breaking,
contains additional matter beyond the MSSM spectrum and avoids the
``doublet-triplet'' splitting problem in the Higgs sector. The calculation is
analytical in two-loop order and includes the effects of the heavy thresholds
due to the additional matter considered. The value of $\alpha_3(M_z)$ can be
brought within the experimental limits without a significant change of the
unification scale from the MSSM prediction.


title: Charged Particle Multiplicity in Diffractive Deep Inelastic Scattering

abstract:
  The recent data from H1 Collaboration on hadron multiplicity in diffractive
DIS has been studied in the framework of perturbative QCD as a function of
invariant diffractive mass. The formulas obtained explain the observed excess
of particle production in diffractive DIS relative to that in DIS and $e^+e^-$
annihilation. It is shown that the results are sensitive to the quark--gluon
structure of the Pomeron. Namely, the data say in favour of a super-hard gluon
distribution at the initial scale.


title: Massive Neutrinos and the Higgs Mass Window

abstract:
  If neutrino masses are produced by a see-saw mechanism the Standard Model
prediction for the Higgs mass window (defined by upper (perturbativity) and
lower (stability) bounds) can be substantially affected. Actually the Higgs
mass window can close completely, which settles an upper bound on the Majorana
mass for the right-handed neutrinos, $M$, ranging from $10^{13}$ GeV for three
generations of quasi-degenerate massive neutrinos with $m_\nu\simeq 2 $ eV, to
$5\times 10^{14}$ GeV for just one relevant generation with $m_\nu\simeq 0.1 $
eV. A slightly weaker upper bound on $M$, coming from the requirement that the
neutrino Yukawa couplings do not develop a Landau pole, is also discussed.


title: Pion--baryon coupling constants in light cone QCD sum rules

abstract:
  We calculate the "pi Sigma Lambda" and "pi Sigma Sigma" coupling constants in
light cone QCD sum rules for the structure "sigma_{alpha beta} gamma_5 p^alpha
q^beta". A comparison of our results on these coupling constants with
prediction of the SU(3) symmetry is presented.


title:
A Redetermination of the Neutrino Mass-Squared Difference in Tri-Maximal
  Mixing with Terrestrial Matter Effects

abstract:
  We re-fit for the neutrino mass-squared difference $\Delta m^2$ in the
threefold maximal (ie. tri-maximal) mixing scenario using recent CHOOZ and
SUPER-K data, taking account of matter effects in the Earth. While matter
effects have little influence on reactor experiments and proposed long-baseline
accelerator experiments with $L \simlt 1000 km$, they are highly significant
for atmospheric experiments, suppressing naturally $\nu_e$ mixing and enhancing
$\nu_{\mu} - \nu_{\tau}$ mixing, so as to effectively remove the experimental
distinction between threefold maximal and twofold maximal
$\nu_{\mu}-\nu_{\tau}$ mixing. Threefold maximal mixing is fully consistent
with the CHOOZ and SUPER-K data and the best-fit value for the neutrino
mass-squared difference is $\Delta m^2 = (0.98 \pm^{0.30}_{0.23}) \times
10^{-3} eV^2$.


title:
Closing the neutrinoless double beta decay window into violations of the
  equivalence principle and/or Lorentz invariance

abstract:
  We have examined Lorentz invariance and equivalence principle violations in
the neutrino sector as manifested in neutrinoless double beta decay. We
conclude that this rare decay cannot provide a useful view of these exotic
processes.


title: Summary of Weak Decays, CKM and CP Violation Session Penguins

abstract:
  In our subgroup, we focused on penguin physics from various different angles.
Our discussions included: (1) A method to extract one of the angles of the
unitarity triangle $\phi_2$; (2) Methods to extract $\phi_3$ from $B\to K\pi$
decays; (3) Effects of non-minimal SUSY on B and K decays; (4) Understnding
large branching ratios for $B\to \eta'+K(K^*)$ decays; (5) New calculation for
hadronic matrix elements which are needed to compute $\epsilon'/\epsilon$.


title:
The polarization of a final electron in the field of intensive
  electromagnetic wave

abstract:
  The polarization properties of the Compton effect in the field of a
circularly polarized electromagnetic wave are discussed. In the case of
nonlinear Compton effect the behavior of spin is analyzed. The transformation
of the longitudinal polarization in the transverse polarization is showed. We
obtained the total formulas describing the polarization of the final electron
in the nonlinear case.


title: A Minimal Superstring Standard Model I: Flat Directions

abstract:
  Three family SU(3)_C x SU(2)_L x U(1)_Y string models in several
constructions generically possess two features: (i) an extra local anomalous
U(1)_A and (ii) numerous (often fractionally charged) exotic particles beyond
those in the minimal supersymmetric model (MSSM). Recently, we demonstrated
that the observable sector effective field theory of such a free fermionic
string model can reduce to that of the MSSM, with the standard observable gauge
group being just SU(3)_C x SU(2)_L x U(1)_Y and the SU(3)_C x SU(2)_L x
U(1)_Y-charged spectrum of the observable sector consisting solely of the MSSM
spectrum. An example of a model with this property was shown. We continue our
investigation of this model by presenting a large set of different flat
directions of the same model that all produce the MSSM spectrum. Our results
suggest that even after imposing the conditions for the decoupling of exotic
states, there may remain sufficient freedom to satisfy the remaining
phenomenological constraints imposed by the observed data.


title: Probing the matter term at long baseline experiments

abstract:
  We consider (\nu_\mu --> \nu_e) oscillations in long baseline experiments
within a three flavor framework. A non-zero measurement of this oscillation
probability implies that the (13) mixing angle `phi' is non-zero. We consider
the effect of neutrino propagation through the matter of earth's crust and show
that, given the constraints from solar neutrino and CHOOZ data, matter effects
enhance the mixing for neutrinos rather than for anti-neutrinos. We need data
from two different experiments with different baseline lengths (such as K2K and
MINOS) to distinguish matter effects unambiguously.


title: Grand-Unification Scale Generation through the Anomalous U(1) Breaking

abstract:
  We discuss the anomalous U(1) gauge symmetry as a mechanism of generating the
grand-unification scale. We conclude that unification to a simple group cannot
be realized unless some parameters are ``tuned'', and that models with product
gauge groups are preferred. We consider the ``R-invariant natural unification''
model with gauge groups SU(5)_{GUT} \times U(3)_H. In this model the
doublet-triplet splitting problem is solved and the unwanted GUT relation m_s =
m_\mu is avoided maintaining m_b = m_\tau. Moreover, R-invariance suppresses
the dangerous proton decays induced by dimension four and five operators.


title: Transcendental numbers and the topology of three-loop bubbles

abstract:
  We present a proof that all transcendental numbers that are needed for the
calculation of the master integrals for three-loop vacuum Feynman diagrams can
be obtained by calculating diagrams with an even simpler topology, the topology
of spectacles.


title: The Potential for the Phase of the Wilson line at Nonzero Quark Density

abstract:
  The contribution of quarks to the effective potential for the phase of the
Wilson line is computed at nonzero temperature and quark chemical potential to
one and two loop order. At zero temperature, regardless of the value of the
quark chemical potential, the effective potential for the phase of the Wilson
line vanishes. At nonzero temperature, for special values of the phase the free
energy of quarks equals that of bosons; at nonzero chemical potential, such
quarks can ``Bose condense'', albeit with negative density.


title: On kinematics and dynamics of independent pion emission

abstract:
  Multiparticle boson states, proposed recently for 'independently' emitted
pions in heavy ion collisions, are reconsidered in standard second quantized
formalism and shown to emerge from a simplistic chaotic current dynamics.
Compact equations relate the density operator, the generating functional of
multiparticle counts, and the correlator of the external current to each other.
'Bose-Einstein-condensation' is related to the external pulse. A quantum master
equation is advocated for future Monte-Carlo simulations.


title: Feynman versus Bakamjian-Thomas in Light Front Dynamics

abstract:
  We compare the Bakamjian-Thomas (BT) formulation of relativistic few-body
systems with light front field theories that maintain closer contact with
Feynman diagrams. We find that Feynman diagrams distinguish Melosh rotations
and other kinematical quantities belonging to various composite subsystem
frames that correspond to different loop integrals. The BT formalism knows only
the rest frame of the whole composite system, where everything is evaluated.


title:
Quantum field theory for discrepancies II: 1/N corrections using
  fermions

abstract:
  We calculate the 1/N corrections to the probability distributions of
quadratic discrepancies for sets of N random points. This is achieved by the
introduction of fermionic variables. We give the diagrammatic expansion up to
and including the second order in 1/N. For some discrepancies, we give the
explicit expansion to first order.


title:
Reply to ``Comment on `Majoron emitting neutrinoless double beta decay
  in the electroweak chiral gauge extensions' ''

abstract:
  We demonstrate that in the process of deducing the constraint on the
electroweak mixing angle $\theta_{W}$ in our paper, we have indeed been working
with three mass scales while implementing (331) model.


title: Matter Antimatter Asymmetry and Neutrino Properties

abstract:
  The cosmological baryon asymmetry can be explained as remnant of heavy
Majorana neutrino decays in the early universe. We study this mechanism for two
models of neutrino masses with a large \nu_\mu-\nu_\tau mixing angle which are
based on the symmetries SU(5) x U(1)_F and SU(3)_c x SU(3)_L x SU(3)_R x
U(1)_F, respectively. In both cases B-L is broken at the unification scale
\Lambda_{GUT}. The models make different predictions for the baryogenesis
temperature and the gravitino abundance.


title:
Searching for New Physics in the b->d FCNC using B_s^0(t)->\phi K_s and
  B_d^0(t)->K^0\bar{K}^0

abstract:
  Time-dependent measurements of the decays B_s^0(t)-->\phi K_s and B_d^0(t)
--> K^0 \bar{K}^0 can be used to compare the weak phases of B_d^0-\bar{B}_d^0
mixing and the t-quark contribution to the b->d penguin. Since these two phases
are equal in the standard model, any discrepancy would be a sign of new
physics, specifically in the b->d flavour-changing neutral current (FCNC). The
method can be applied to other pairs of decays, such as B_s^0(t)--> J/\Psi K_s
and B_d^0(t)--> J/\Psi \pi^0.


title: Neutrino Magnetic Moments and Atmospheric Neutrinos

abstract:
  I review the history on neutrino magnetic moments and apply the neurino
magnetic moment idea to constrain its bound from Super-Kamiokande neutrino
oscillation data.


title: A Critical Look at $\gamma$ Determinations from $B\to\pi K$ Decays

abstract:
  The determination of the angle $\gamma$ of the unitarity triangle of the CKM
matrix is a challenge for the $B$-factories. In this context, $B\to\pi K$
decays received a lot of attention, providing various interesting ways to
constrain and determine $\gamma$. These strategies are briefly reviewed, and
their virtues and weaknesses are compared with one another.


title:
New results from experiment WA102: A partial wave analysis of the
  centrally produced KK and pipi systems

abstract:
  A partial wave analysis of the centrally produced KK and pipi systems shows
that the fJ(1710) has J = 0. In addition, a study of central meson production
as a function of the difference in transverse momentum (dPT) of the exchanged
particles shows that undisputed qqbar mesons are suppressed at small dPT
whereas the glueball candidates are enhanced and that the production cross
section for different resonances depends strongly on the azimuthal angle
between the two outgoing protons.


title: Preheating in Supersymmetric Hybrid Inflation

abstract:
  We study preheating in a general class of supersymmetric hybrid inflation
model. Supersymmetry leads to only one coupling constant in the potential and
thus only one natural frequency of oscillation for the homogeneous fields,
whose classical evolution consequently differs from that of a general
(non-supersymmetric) hybrid model. We emphasise the importance of mixing
effects in these models which can significantly change the rate of production
of particles. We perform a general study of the rate of production of the
particles associated with the homogeneous fields, and show how preheating is
efficient in producing these quanta. Preheating of other particle species will
be model dependent, and in order to investigate this we consider a realistic
working model of supersymmetric hybrid inflation which solves the strong-CP
problem via an approximate Peccei-Quinn symmetry, which was proposed by us
previously. We study axion production in this model and show that properly
taking into account the mixing between the fields suppresses the axion
production, yet enhances the production of other particles. Finally we
demonstrate the importance of backreaction effects in this model which have the
effect of shutting off axion production, leaving the axion safely within
experimental bounds.


title: Four-neutrino spectrum from oscillation data

abstract:
  It is shown that the Super-Kamiokande atmospheric up--down asymmetry,
together with the results of all other neutrino oscillation experiments, allows
to constraint the possible spectra of four massive neutrinos. The two schemes
with two pairs of neutrinos with close masses separated by a gap of about 1 eV
are favored by the data.


title: Analysis of deep inelastic scattering with $z$-dependent scale

abstract:
  Evolution of the parton densities at NLO in $\alpha_S$ using $\tilde W^2 =
Q^2 (1-z)/z$ instead of the usual $Q^2$ for the scale of the running coupling
$\alpha_S$ is investigated. While this renormalisation scale change was
originally proposed as the relevant one for $x \to 1$, we explore the
consequences for all $x$ with this choice. While it leads to no improvement to
the description of DIS data, the nature of the gluon at low $x$, low $Q^2$ is
different, avoiding the need for a `valence-like' gluon.


title: Gravitons and the Drell-Hearn-Gerasimov Sum Rule

abstract:
  One-loop diagrams containing a graviton provide a finite contribution to the
anomalous magnetic moment $\al$ of a lepton, whether or not the graviton
propagates in $n$ large extra compact dimensions. In the present work, the tree
graph photoproduction of a graviton, integrated up to an arbitrary cutoff, is
shown to violate the Drell-Hearn-Gerasimov sum rule for $\al^2$. The
possibility of resurrecting the sum rule from high energy contributions
originating in string excitations is discussed in a qualitative manner, and
various problems associated with such a program are pointed out.


title:
Longitudinal quark polarization in e+e- --> t tbar and chromoelectric
  and chromomagnetic dipole couplings of the top quark

abstract:
  The effect of anomalous chromomagnetic (mu) and chromoelectric couplings (d)
of the gluon to the top quark are considered in e+ e- --> t tbar, with
unpolarized and longitudinally polarized electron beams. The total cross
section, as well as t and tbar polarizations are calculated to order alpha_s in
the presence of the anomalous couplings. One of the two linear combinations of
t and tbar polarizations is CP even, while the other is CP odd. The limits that
could be obtained at a typical future linear collider with an integrated
luminosity of 50 1/fb and a total c.m. energy of 500 GeV on the most sensitive
CP-even combination of anomalous couplings are estimated as -3 < Re(mu) < 2 for
Im(mu) = 0 = d, and sqrt{Im(mu)^2 + |d|^2} < 2.25 for Re(mu) = 0. There is an
improvement by roughly a factor of 2 at 1000 GeV. On the other hand, from the
CP-odd combination, we derive the possible complementary bounds as -3.6 <
Im(mu^* d) < 3.6 for Im(d) = 0, and -10 < Im(d) < 10 for Im(mu^* d) = 0, at a
c.m. energy of 500 GeV. The corresponding limit for 1000 GeV is almost an order
of magnitude better for Im(mu^* d), though somewhat worse for Im(d). Results
for the c.m. energies 500 GeV and 1000 GeV, if combined, would yield independen
limits on the two CP-violating parameters of -0.8 < Im(mu^* d) < 0.8 and -11 <
Im(d) < 11.


title: Jet cross sections in polarized photon-hadron collisions

abstract:
  We present a computation of one- and two-jet cross sections in polarized
photon-hadron collisions, which is accurate to next-to-leading order in QCD.
Our results can be used to compute photoproduction cross sections in
electron-proton scattering. To this purpose, we investigate the structure of
the polarized Weizsaecker-Williams function, where we include a universal,
non-logarithmic term, neglected in the literature. We construct a Monte Carlo
code, within the framework of the subtraction method, and we use it to study
the phenomenology of jet production in the energy range relevant to HERA. In
particular, we investigate the perturbative stability of our results, and we
discuss the possibility of constraining polarized parton densities of the
proton and the photon using jet data.


title: Exploring the Weak Phase gamma in B^+- -> pi K Decays

abstract:
  Measurements of the rates for the hadronic decays B^+- -> pi K along with the
CP-averaged B^+- -> pi^+- pi^0 branching ratio can be used to bound and extract
the weak phase gamma=-arg(V_ub). Using preliminary CLEO data, we obtain the
bounds |gamma|>93 degrees at 1 sigma, and |gamma|>71 degrees at 90 % confidence
level.


title: String Model for Analytic Nonlinear Regge Trajectories

abstract:
  We present a new generalized string model for Regge trajectories J=J(E^2),
where J and E are the orbital momentum and energy of the string, respectively.
We demonstrate that this model is not to produce linear Regge trajectories, in
contrast to the standard Nambu-Goto string, but generally nonlinear
trajectories, which in many cases can be given in analytic form. As an example,
we show how the model generates square-root, logarithmic and hyperbolic
trajectories that have been discussed in the literature.


title:
Non-leptonic Two-meson Decays of B-Mesons in the Covariant Oscillator
  Quark Model with Factorization Ansatz

abstract:
  Exclusive nonleptonic bottom meson decays are studied in the covariant
osillator quark model using the factorization assumption. The main feature of
this model is that it can simultaniously be applied to both heavy to heavy and
heavy to light transitions, satisfying the constraints of the heavy quark
effective theory (HQET) in the appropriate limit. The results obtained are in
overall agreement with the present experimental data for various B decays.


title:
Hadronic Weak Decays of Lambda b Baryon in the Covariant Oscillator
  Quark Model

abstract:
  Cabibbo allowed two-body hadronic weak decays of Lambda b baryons are
analyzed in the factorization approximation. We use the covariant oscillator
quark model to evaluate the heavy to heavy and heavy to light form factors.
When applied in the heavy quark limit, our form factors satisfy all the
constraints imposed by heavy quark symmetry. The decay rates and up-down
asymmetries for Lambda b baryon decaying into Lambda c +P(V) are calculated. It
is found that the up-down asymmetry is negative in all these decay modes.
Furthermore, the prediction Br(Lambda b to Lambda+J/psi)=2.49 times 10^-4 is
consistent with the recent experimental data. Finally it is pointed out that
the CKM-Wolfenstein parameter rho^2+eta^2, where eta is the CP phase, can be
determined from the ratio of the widths Lambda b to Lambda bar D^0 and Lambda b
to Lambda J/psi, independent of the QCD parameter. The value of (rho^2
+eta^2)^1/2 calculated in our model agrees very well with the value recently
predicted by Rosner.


title:
Exclusive Weak Radiative Decays of B Mesons in the Covariant Oscillator
  Quark Model

abstract:
  Exclusive weak radiative B meson decays are studied using the covariant
oscillator quark model. The branching ratios for the processes B0 to K*0 gamma
and B to K* gamma have been estimated. These are in reasonable agreement with
the available experimental data. The calculation has been extended to the
CKM-suppressed decay processes B- to rho- gamma and Bs to K*0 gamma .


title: Exclusive hadron production in e^+e^- collisions up to the J/psi energy

abstract:
  The predictions are presented for the diagonal and transition form factors of
light hadrons in the time-like region up to the production threshold of an open
charm quantum number. The comparison with existing data on the decays of J/psi
and psi(2S) mesons into such hadrons shows that some new resonance structures
may be present in the mass range between 2 GeV and the J/psi mass. Searching
them may help in a better understanding of the mass spectrum in quark models,
and in revealing the details of the three-gluon mechanism of the OZI rule
breaking.


title:
Some aspects of electroweak physics for a composite Higgs boson:
  application to the Z gauge boson decaying into two leptons and two
  pseudoscalar mesons

abstract:
  I study phenomenological aspects of the SU(2)L x U(1) electroweak physics of
a Higgs boson transforming like a quark-antiquark pair. A correspondence is
established between its flavour content, the hierarchy of quark condensates,
and the leptonic decay constants f of pseudoscalar mesons; the Higgs-mesons
couplings coming from the symmetry-breaking scalar potential can then be
expressed in terms of the f's, of the Cabibbo-Kobayashi-Maskawa mixing angles,
and of the mass of the Higgs boson. Application is made to the decays of a Z
boson into two leptons and two charged pseudoscalar mesons, more specially
$e^+e^- B^+B^-, e^+e^- D_s^+D_s^-$ and $e^+e^- K^\pm \pi^\mp$; the last
channel, involving new types of flavour changing neutral currents in the scalar
sector, is characteristic of this approach. Unlike in the standard model for
quarks, the detection of two outgoing charged $B$ mesons is hopeless, like,
unfortunately, that of $K^\pm \pi^\mp$; the channel $D_s^+ D_s^-$ could have
been missed in present experiments for a Higgs mass lower than $65 GeV$ because
of insufficient statistics. For higher masses this Higgs becomes undetectable
from such channels. This shows that too drastic conclusions should not be drawn
from an eventual negative outcome from searches for the standard Higgs boson,
that simple variants of it are more elusive, may have escaped detection, and
could still escape in the near future.


title: Neutrino oscillation constraints on neutrinoless double-beta decay

abstract:
  It is shown that, in the framework of the scheme with three-neutrino mixing
and a mass hierarchy, the results of neutrino oscillation experiments imply an
upper bound of about 10^{-2} eV for the effective Majorana mass in neutrinoless
double-beta decay. The schemes with four massive neutrinos are also briefly
discussed.


title: Penguins in CP violating B decays

abstract:
  The role of penguin amplitudes in CP violating $B$ decays is reviewed,
emphasizing recent progress in the analysis of electroweak penguin
contributions. It is shown how these terms are included in a model-independent
manner when measuring the weak phase $\alpha$ in $B\to\pi\pi$ using isospin
symmetry, and when determining the phase $\gamma$ from $B\to K\pi$ applying
flavor SU(3). Uncertainties due to rescattering effects in $B\to K\pi$ are
discussed.


title: Quark Confinement and the Hadron Spectrum

abstract:
  These lectures contain an introduction to the following topics: 1)
Phenomenology of the hadron spectrum; 2) The static Wilson loop in perturbative
and in lattice QCD. Confinement and the flux tube formation; 3) Non static
properties: effective field theories and relativistic corrections to the
quarkonium potential; 4) The QCD vacuum: minimal area law, Abelian projection
and dual Meissner effect, stochastic vacuum.


title: Oscillations, Neutrino Masses and Scales of New Physics

abstract:
  We show that all the available experimental information involving neutrinos
can be accounted for within the framework of already existing models where
neutrinos have zero mass at tree level, but obtain a small Dirac mass by
radiative corrections.


title:
The NNLO QCD analysis of the CCFR data for xF_3: is there still the room
  for the twist-4 terms?

abstract:
  The results of the more detailed NNLO QCD analysis of the CCFR data for
$xF_3$ SF are presented. The factorization scale uncertainties are analysed.
The NNLO results for $alpha_s(M_Z)$ and twist-4 contributions are obtained.
Despite the fact that the amplitude of the $x$-shape of the twist-4 factor is
consequently decreasing at the NLO and NNLO, our new QCD analysis seems to
reveal the remaining twist-4 structure at the NNLO level. The definite N$^3$LO
uncertainties are fixed using the [0/2] Pad\'e resummation technique.


title: Ring diagrams and electroweak phase transition in a magnetic field

abstract:
  Electroweak phase transition in a magnetic field is investigated within the
one-loop and ring diagram contributions to the effective potential in the
minimal Standard Model. All fundamental fermions and bosons are included with
their actual values of masses and the Higgs boson mass is considered in the
range $75 GeV \leq m_H \leq 115 GeV$. The effective potential is real at
sufficiently high temperature. The important role of fermions and $W$-bosons in
symmetry behaviour is observed. It is found that the phase transition for the
field strengths $10^{23} - 10^{24}$G is of first order but the baryogenesis
condition is not satisfied. The comparison with the hypermagnetic field case is
done.


title:
Global Analysis of eeqq Contact Interactions and Future Prospects for
  High Energy Physics

abstract:
  Data from HERA, LEP and the Tevatron, as well as from low energy experiments
are used to constrain the scale of possible electron-quark contact
interactions. Different models are considered, including the most general one,
in which all new couplings can vary independently. Limits on couplings and mass
scales are extracted and upper limits on possible effects to be observed in
future HERA, LEP and Tevatron running are estimated. Total hadronic
cross-section at LEP and e-p scattering cross-section at HERA are strongly
constrained by existing data, whereas large cross-section deviations are still
possible for Drell-Yan lepton pair production at the Tevatron.


title:
Exotic muon-electron conversion in nuclei and R-parity violating
  supersymmetry

abstract:
  The flavor violating $\mu^--e^-$ conversion in nuclei is studied within the
minimal supersymmetric standard model. We focus on the R-parity violating
contributions at tree level including the trilinear and the bilinear terms in
the superpotential as well as in the soft supersymmetry breaking sector. The
nucleon and nuclear structure have consistently been taken into account in the
expression of the $\mu^--e^-$ conversion branching ratio constructed in this
framework. We have found that the contribution of the strange quark sea of the
nucleon is comparable with that of the valence quarks. From the available
experimental data on $\mu^--e^-$ conversion in $^{48}$Ti and $^{208}$Pb and the
expected sensitivity of the MECO experiment for $^{27}$Al we have extracted new
stringent limits on the R-parity violating parameters.


title: Implications of mirror neutrinos for early universe cosmology

abstract:
  The Exact Parity Model (EPM) is, in part, a theory of neutrino mass and
mixing that can solve the atmospheric, solar and LSND anomalies. The central
feature of the neutrino sector is three pairs of maximally mixed ordinary and
mirror neutrinos. It has been shown that ordinary-mirror neutrino oscillations
can generate large neutrino asymmetries in the epoch of the early universe
immediately prior to Big Bang Nucleosynthesis (BBN). The large neutrino
asymmetries generically suppress the production of mirror neutrinos, and a
sufficiently large $\nu_e$ asymmetry can directly affect light element
synthesis through nuclear reaction rates. In this paper we present a detailed
calculation of neutrino asymmetry evolution driven by the six-flavour EPM
neutrino sector, focusing on implications for BBN.


title: Diamond degradation in hadron fields

abstract:
  The energy dependence of the concentration of primary displacements induced
by protons and pions in diamond has been calculated in the energy range 50 MeV
- 50 GeV, in the frame of the Lindhard theory. The concentrations of primary
displacements induced by protons and pions have completely different energy
dependencies: the proton degradation is very important at low energies, and is
higher than the pion one in the whole energy range investigated, with the
exception of the delta33 resonance region. Diamond has been found,
theoretically, to be one order of magnitude more resistant to proton and pion
irradiation in respect to silicon.


title:
Democratic Mass Matrices from Broken $O(3)_L\times O(3)_R$ Flavor
  Symmetry

abstract:
  We impose $O(3)_L\times O(3)_R$ flavor symmetry in the supersymmetric
standard model. Three lepton doublets $\ell_i$ transform as an $O(3)_L$ triplet
and three charged leptons $\bar e_i$ as an $O(3)_R$ triplet, while Higgs
doublets $H$ and $\bar H$ are $O(3)_L\times O(3)_R$ singlets. We discuss a
flavor $O(3)_L\times O(3)_R$ breaking mechanism that leads to "successful"
phenomenological mass matrices, so-called "democratic" ones, in which the large
$\n_\mu-\n_\tau$ mixing is naturally obtained. Three neutrinos have nearly
degenerate masses of order $0.1\eV$ which may be accesible to future double
$\b$-decay experiments. We extend our approach to the quark sector and show
that it is well consistent with the observed quark mass hierarchies and the CKM
matrix elements. However, the large mass of the top quark requires a relatively
large coupling. constant.


title: Two photon decays of scalar mesons in a covariant quark model

abstract:
  Two photon decay widths of the $J^P = O^+$ scalar mesons $a_{0} (980)$,
$f_{0}(980)$, $f_{0}(1370)$ and $\chi_{c0}$ are calculated in a covariant model
which is characterized by the quark - antiquark structure. Previously such
models were used to calculate current form factors. Here a different
application is tried. A simple version of the model uses adjusted
nonrelativistic model parameters with small quark masses. The results seem to
prefer nonideal mixing of $f_0(980)$ and $f_0(1370)$. The calculated decay rate
of $\chi_{c0}$ agrees with the experimental results.


title: Field-theoretical treatment of neutrino oscillations

abstract:
  We discuss the field-theoretical approach to neutrino oscillations. This
approach includes the neutrino source and detector processes and allows to
obtain the neutrino transition or survival probabilities as cross sections
derived from the Feynman diagram of the combined source -- detection process.
In this context, the neutrinos which are supposed to oscillate appear as
propagators of the neutrino mass eigenfields, connecting the source and
detection processes.