title: Large Field Inflation in Supergravity

abstract:
  We present a supergravity inflationary scenario in which the inflaton field
takes values considerably larger than the Planck scale. It is based on a class
of inflationary potentials which can be derived from ``singular'' Kaehler
potentials assuming simple superpotentials of the type $W\simS^n$. To this
class belong, among many others, all potentials which are even infinitesimally
smaller than the one derived from the minimal Kaehler potential. Our scenario
allows for a detectable gravitational wave contribution to the microwave
background anisotropy.


title:
Multi-Parton Loop Amplitudes and Next-to-Leading Order Jet
  Cross-Sections

abstract:
  We review recent developments in the calculation of QCD loop amplitudes with
several external legs, and their application to next-to-leading order jet
production cross-sections. When a number of calculational tools are combined
together --- helicity, color and supersymmetry decompositions, plus unitarity
and factorization properties --- it becomes possible to compute multi-parton
one-loop QCD amplitudes without ever evaluating analytically standard one-loop
Feynman diagrams. One-loop helicity amplitudes are now available for processes
with five external partons (ggggg, q\bar{q}ggg and q\bar{q}q'\bar{q}'g), and
for an intermediate vector boson V \equiv \gamma^*,Z,W plus four external
partons (Vq\bar{q}gg and Vq\bar{q}q'\bar{q}'). Using these amplitudes,
numerical programs have been constructed for the next-to-leading order
corrections to the processes p\bar{p} to 3 jets (ignoring quark contributions
so far) and e^+e^- to 4 jets.


title: Precision measurements of threshold chargino production

abstract:
  We analyze the prospects at a muon collider for measuring chargino masses in
the $\mu^+\mu^-\to \tilde{\chi}^+\tilde{\chi}^-$ processes in the threshold
region. We find that a measurement of the lightest chargino mass to better than
200 MeV is possible with 100~fb$^{-1}$ luminosity. The muon sneutrino mass can
also be simultaneously measured to a few GeV.


title: Search for Anomaly at High x in Polarized Deep Inelastic Scattering Data

abstract:
  An idea of possible anomalous contribution of non-perturbative origin to the
nucleon spin was examined by analysing data on spin asymmetries in polarized
deep inelastic scattering of leptons on nucleons. The region of high Bjorken x
was explored. It was shown that experimental data available at present do not
evidence for this effect.


title: Further all-loop results in softly-broken supersymmetric gauge theories

abstract:
  It is proven that the recently found, renormalization-group invariant sum
rule for the soft scalar masses in softly-broken N=1 supersymmetric
gauge-Yukawa unified theories can be extended to all orders in perturbation
theory. In the case of finite unified theories, the sum rule ensures the
all-loop finiteness in the soft supersymmetry breaking sector. As a byproduct
the exact $\beta$ function for the soft scalar masses in the
Novikov-Shifman-Vainstein-Zakharov (NSVZ) scheme for softly-broken
supersymmetric QCD is obtained. It is also found that the singularity appearing
in the sum rule in the NSVZ scheme exactly coincides with that which has been
previously found in a certain class of superstring models in which the massive
string states are organized into $N = 4$ supermultiplets.


title: Charge asymmetry in hadroproduction of heavy quarks

abstract:
  A sizeable difference in the differential production cross section of top and
antitop quarks, respectively, is predicted for hadronically produced heavy
quarks. It is of order $\alpha_s$ and arises from the interference between
charge odd and even amplitudes respectively. For the TEVATRON it amounts to
approximately 5-10% in the region where the cross section is large and could
therefore be measured in the next round of experiments. At the LHC the
asymmetry can be studied by selecting appropriately chosen kinematical regions.


title: A characteristic plot of pomeron-exchanged processes in diffractive DIS

abstract:
  The dependence of the fractal behaviors of the pomeron induced system in deep
inelastic lepton-nucleon scattering upon the diffractive kinematic variables is
found rather robust and not sensitive to the distinct parameterization of the
pomeron flux factor and structure function. A feasible experimental test of the
phenomenological pomeron-exchanged model based on the fractal measurement in
DESY $ep$ collider HERA is proposed.


title:
Searching for Cold Dark Matter. A case of coexistence of Supersymmetry
  and Nuclear Physics

abstract:
  The direct detection rate for supersymmetric cold dark matter (CDM) particles
is calculated for a number of suitable nuclear targets. Both the coherent and
spin contributions are considered. By considering representative
phenomenologically acceptable input in the restricted SUSY parameter space,
detectable rates are predicted for some choices of the parameters. The
modulation effect, due to the Earth's annual motion, has also been considered
and found to be $\le 4%$. Its precise value depends on the mass of CDM
particles (LSP) and the structure of the target.


title: Spectrum of Background X-rays from Moduli Dark Matter

abstract:
  We examine the $X$-ray spectrum from the decay of the dark-matter moduli with
mass $\sim {\cal O}(100)$keV, in particular, paying attention to the line
spectrum from the moduli trapped in the halo of our galaxy. It is found that
with the energy resolution of the current experiments ($\sim 10$%) the line
intensity is about twice stronger than that of the continuum spectrum from the
moduli that spread in the whole universe. Therefore, in the future experiments
with higher energy resolutions it may be possible to detect such line photons.
We also investigate the $\gamma$-ray spectrum emitted from the decay of the
multi-GeV moduli. It is shown that the emitted photons may form MeV-bump in the
$\gamma$-ray spectrum. We also find that if the modulus mass is of the order of
10 GeV, the emitted photons at the peak of the continuum spectrum loses their
energy by the scattering and the shape of the spectrum is significantly
changed, which makes the constraint weaker than that obtained in the previous
works.


title:
Reply to the criticism raised by Pennington on our pipi-Production
  Amplitudes

abstract:
  A recent criticism raised by M.R.Pennington on our pipi-production amplitudes
seems to be due to his misunderstanding on our description, and is not right.
Essential point of the relation between our scattering and production
amplitudes is, in connection to the unitarity and the final state interaction
theorem, briefly explained.


title: Field Strength Correlators and Dual Effective Dynamics in QCD

abstract:
  We establish a relation between the two-point field strength correlator in
QCD and the dual field propagator of an effective dual Abelian Higgs model
describing the infrared behaviour of QCD. We find an analytic approximation to
the dual field propagator without sources and in presence of quark sources. In
the latter situation we also obtain an expression for the static $q \bar{q}$
potential. Our derivation sheds some light on the dominance and
phenomenological relevance of the two-point field strength correlator.


title: QCD Field Strength Correlator at the One-Loop Order

abstract:
  The leading perturbative contributions into the two-point gauge-invariant
correlator $Tr<gF(x)U(x,0)U(0,y)F(y)U(y,0)U(0,x)>$ are calculated at the
one-loop order. It is shown, that nonlocal condensate is nonzero at this order.
The relation with the renormalization properties of Wilson loops is discussed.


title: Charged Scalar Phenomenology in the Bilinear R-Parity Breaking Model

abstract:
  We consider the charged scalar boson phenomenology in the bilinear R-parity
breaking model which induces a mixing between staus and the charged Higgs
boson. The charged Higgs boson mass can be lower than expected in the MSSM,
even before including radiative corrections. The R-parity violating decay rates
can be comparable or even bigger than the R-parity conserving ones. These
features could have implications for charged supersymmetric scalar boson
searches at future accelerators.


title: Spontaneous CP Violation at Finite Temperature in the MSSM

abstract:
  By studying the effective potential of the MSSM at finite temperature, we
find that CP can be spontaneously broken in the intermediate region between the
symmetric and broken phases separated by the bubble wall created at the phase
transition. This type of CP violation is necessary to have a bubble wall
profile connecting CP conserving vacua, while violating CP halfway and
generating sufficient baryon number without contradiction to the experimantal
bounds on CP violations. Several conditions on the parameters in the MSSM are
found for CP to be broken in this manner.


title:
Evolution of Inhomogeneous Condensates: Self-consistent Variational
  Approach

abstract:
  We establish a self-consistent variational framework that allows us to study
numerically the non-equilibrium evolution of non-perturbative inhomogeneous
field configurations including quantum backreaction effects. After discussing
the practical merits and disadvantages of different approaches we provide a
closed set of local and renormalizable update equations that determine the
dynamical evolution of inhomogeneous condensates and can be implemented
numerically. These incorporate self-consistently the backreaction of quantum
fluctuations and particle production. This program requires the solution of a
self-consistent inhomogeneous problem to provide initial Cauchy data for the
inhomogeneous condensates and Green's functions. We provide a simple solvable
ansatz for such an initial value problem for the Sine-Gordon and phi^4 quantum
field theories in one spatial dimension. We compare exact known results of the
Sine Gordon model to this simple ansatz. We also study the linear sigma model
in the large N limit in three spatial dimensions as a microscopic model for
pion production in ultrarelativistic collisions. We provide a solvable self-
consistent ansatz for the initial value problem with cylindrical symmetry. For
this case we also obtain a closed set of local and renormalized update
equations that can be numerically implemented. A novel phenomenon of spinodal
instabilities and pion production arises as a result of a Klein paradox for
large amplitude inhomogeneous condensate configurations.


title:
Possible probe of the QCD odderon singularity through the
  quasidiffractive eta_c production in gamma-gamma collisions

abstract:
  The reactions gamma-gamma to eta_c eta_c and gamma gamma to eta_c + X are
discussed within the three gluon exchange model. We give predictions for the
differential cross-sections and discuss feasibility of measuring these
processes at LEP2 and TESLA. The total cross-sections were estimated to be
approximately equal to 40 fb and 120 fb for gamma-gamma to eta_c eta_c and
gamma-gamma to eta_c + X respectively assuming exchange of elementary gluons
that corresponds to the odderon with intercept equal to unity. These values can
be enhanced by a factor equal to 1.9 and 2.1 for LEP2 and TESLA energies if the
odderon intercept is equal to 1.07. The estimate of cross-sections sigma(e^+
e^- to e^+ e^- eta_c eta_c) and sigma (e^+ e^- to e^+ e^- eta_c + X) for
untagged e^+ and e^- is also given.


title: Top Quark Physics at a Polarized Muon Collider

abstract:
  Top quark pair production is presented at a polarized Muon Collider above the
threshold region. The off-diagonal spin basis is the natural basis for this
discussion as the top quark pairs are produced in an essentially unique spin
configuration for 100% polarization. Modest polarization, say 30%, can lead to
90% of all top quark pair events being in one spin configuration. This will
lead to sensitive tests on anomalous top quark couplings.


title: Constraints on Finite Soft Supersymmetry Breaking Terms

abstract:
  A new solution to the requirement of two-loop finiteness of the soft
supersymmetry breaking terms (SSB) parameters is found in Finite-Gauge-Yukawa
unified theories. The new solution has the form of a sum rule for the relevant
scalar masses, relaxing the universality required by the previously known
solution, which leads to models with unpleasant phenomenological consequences.
Using the sum rule we investigate two Finite-Gauge-Yukawa unified models and we
determine their spectrum in terms of few parameters. Some characteristic
features of the models are that a) the old agreement of the top quark mass
prediction with the measured value remains unchanged, b) the lightest Higgs
mass is predicted around 120 GeV, c) the s-spectrum starts above 200 GeV.


title:
CP Violation from Surface Terms in the Electroweak Theory without
  Fermions

abstract:
  We consider the effect of adding a CP-odd, theta FFdual-term to the
electroweak Lagrangian without fermions. This term affects neither the
classical nor perturbatively quantum physics, but can be observed through
non-perturbative quantum processes. We give an example of such a process by
modifying the theory so that it supports Higgs-winding solitons and showing
that the rates of decay of these solitons to specific final states are CP
violating. We also discuss how the CP symmetry is restored when fermions are
included.


title:
Analytic Perturbation Theory and Renormalization Scheme Dependence in
  Tau Decay

abstract:
  We apply analytic perturbation theory in next-to-next-to-leading order to
inclusive semileptonic $\tau$-decay and study the renormalization scheme
dependence. We argue that the renormalization scheme ambiguity is considerably
reduced in the analytic perturbation theory framework and we obtain a rather
stable theoretical prediction.


title: Stringy Mass Squared Splittings Revisited

abstract:
  An empirically successful mass formula derived long ago from hadronic string
models is not explained by symmetries of the QCD lagrangian. Consider that
M(rho)^2-M(pi)^2 = M(K*)^2-M(K)^2 to a few percent accuracy. We derive this and
other equal spacing relations using chiral symmetry and a novel Z_2 symmetry.
We offer an interpretation of this Z_2 symmetry as a manifestation of chiral
anomalies in a gauge theory with an intrinsic cutoff.


title: Color Superconductivity and Signs of its Formation

abstract:
  We study finite density QCD in an approximation in which the interaction
between quarks is modelled on that induced by instantons. We sketch the
mechanism by which chiral symmetry restoration at finite density occurs in this
model. At all densities high enough that the chirally symmetric phase fills
space, we find that color symmetry is broken by the formation of a $< qq >$
condensate of quark Cooper pairs. The formation of this color superconductor
condensate lowers the energy of the system most if the up and down quark
chemical potentials are equal. This suggests that the formation of such a
condensate in a heavy ion collision may be accompanied by radiation of negative
pions, and its decay may yield more protons than were present in the incident
nuclei.


title: Reheating and Preheating after Inflation

abstract:
  It is assumed that during inflation, all energy was contained in a
slow-rolling inflaton field $\phi$. The particles constituting the Universe are
created due to interactions with the field $\phi$ coherently oscillating after
inflation. The leading channel of the particle production would be the
non-perturbative regime of parametric resonance, preheating. Some of the recent
developments in the theory of preheating are briefly reviewed. As a prototype
we use the model ${\lambda\over 4}\phi^4 + {m^2 \over 2}\phi^2+ {g^2\over
2}\phi^2\chi^2$ in an expanding universe. In different domains of parameters
the character of preheating $(\phi \to \chi)$ or $(\phi \to \delta \phi)$ is
different, ranging from regular Lam\'{e} to stochastic parametric resonances.
Fortunately, in many important cases simple analytic resonant solutions are
found. Eventually, a picture which unifies the different regimes emerges.


title:
New explanation of the GAMS results on the $f_0(980)$ production in the
  reaction $\pi^-p\to \pi^0\pi^0n$

abstract:
  The observed alteration of the S-wave $\pi^0\pi^0$ mass spectrum in the
reaction $\pi^-p\to\pi^0\pi^0n$ with increasing $-t$, i.e., the disappearance
of a dip and the appearance of a peak in the region of the $f_0(980)$ resonance
as $-t$ increases, is explained by the contribution of the $\pi^-p\to
f_0(980)n$ reaction amplitude with the quantum numbers of the $a_1$ Regge pole
in the $t$ channel. It is very interesting that nontrivial evidence for the
$a_1$ exchange mechanism in the reaction $\pi^-p\to \pi^0\pi^0n$ follows for
the first time from the experiment on an unpolarized target. The explanation of
the GAMS results suggested by us is compared with that reported previously. Two
ways of experimentally testing these explanations are pointed out.


title:
Confronting solutions to the atmospheric neutrino anomaly involving
  large angle $\nu_{\mu} \to \nu_e$ oscillations with SuperKamiokande and CHOOZ

abstract:
  Neutrino oscillation scenarios involving large angle $\nu_{\mu} \to \nu_e$
oscillations are disfavoured in the parameter range $\Delta m^2/eV^2 >~
10^{-3}$ by recent results from the CHOOZ reactor-based $\bar{\nu}_e$
disappearance experiment. For this reason we extend our previous work on
up-down asymmetries for various oscillation scenarios by computing up-down
asymmetries and the R ratio for the entire conceivable range $10^{-4} - 10^{-1}
eV^2$ of $\Delta m^2$. Matter effects in the Earth play a crucial role. We
perform a $\chi^2$ fit to the data. We find that, because of the matter effect,
the three-flavour maximal mixing model provides a reasonable fit to
SuperKamiokande and CHOOZ data provided that the relevant $\Delta m^2$ is in
the range $4 \times 10^{-4} ~< \Delta m^2/eV^2 ~< 1.5 \times 10^{-3}$.


title: Quantization of an interacting spin-3/2 field and the Delta isobar

abstract:
  Quantization of the free and interacting Rarita-Schwinger field is considered
using the Hamiltonian path-integral formulation. The particular interaction we
study in detail is the $\pi N \De$ coupling used in the phenomenology of the
pion-nucleon and nucleon-nucleon systems. Within the Dirac constraint analysis,
we show that there is an excess of degrees of freedom in the model, as well as
the inconsistency related to the Johnson-Sudarshan-Velo-Zwanzinger problem. It
is further suggested that couplings invariant under the gauge transformation of
the Rarita-Schwinger field are generally free from these inconsistencies. We
then construct and briefly analyse some lowest in derivatives gauge-invariant
$\pi N \De$ couplings.


title: Constraints on the parameters of the $V_{CKM}$ matrix at the end of 1997

abstract:
  A review of the current status of the Cabibbo-Kobayashi-Maskawa matrix V_CKM
is presented. This paper contains an update of the results published in
hep-ph/9711261. Values of the parameters entering into the constraints, which
restrict the range for rho and eta parameters, include recent measurements
given at 1997 Summer Conferences and progress obtained by lattice QCD
collaborations.Experimental constraints imposed by the measurements of
epsilon_k,V_ub/V_cb, Delta m_d and by the limit on Delta m_s, are compatible
and do not show evidence for New Physics inside measurements errors. Values for
the angles alpha, beta and gamma of the C.K.M. triangle have been also
obtained: rho=0.156 +- 0.090, eta=0.328 +- 0.054 sin 2alpha = -0.10+-0.40, sin
2beta = 0.68 +- 0.10, gamma= 64+-12 Angles theta,theta_u,theta_d and phi
proposed in the parametrisation (Phys. Lett. B5353 (1995) 114.) of the C.K.M.
matrix have been also determined. Finally, as there are more constraints than
the fitted rho and eta parameters, several external measurements or theoretical
inputs have been removed, in turn, from the constraints and their respective
values have been fitted simultaneously with rho and eta.Central values and
uncertainties on these quantities have been compared with actual measurements
or theoretical evaluations. In this way it is possible to quantify the
importance of the different measurements and the coherence of the Standard
Model scenario for CP violation.


title: BFKL pomeron in the next-to-leading approximation

abstract:
  We find one-loop correction to the integral kernel of the BFKL equation for
the total cross section of the high energy scattering in QCD and calculate the
next-to-leading contribution to anomalous dimensions of twist-2 operators near
$j=1$.


title: Can Nearby Resonances Enhance D^0 - anti-D^0 Mixing?

abstract:
  We consider the possibility that D^0 - anti-D^0 mixing undergoes resonant
enhancement. Various scenarios are explored, including the potential effects of
nearby pseudoscalar or scalar quark-antiquark (Q - anti-Q) resonances as well
as of hybrid quark-antiquark-gluon Q - anti-Q G states. Assuming reasonable
values for the resonance parameters we find relatively sizeable contributions
from individual resonances to both \Delta m_D and \Delta \Gamma_D. We derive a
variant of the GIM cancellation mechanism for the resonance amplitudes and show
that broken SU(3) can allow for sizeable residual effects. Additional input
from meson spectroscopy and lattice gauge simulations will be needed to improve
the accuracy of these predictions.


title: Supersymmetry without R--Parity

abstract:
  In this talk I discuss the motivations for supersymmetry, focussing on models
with broken R-parity and lepton number. After describing the main theoretical
features of these models, I discuss some of the signals expected at colliders
such as Tevatron, LEP II, NLC and LHC.


title: Signatures for the Charged Higgs Decay of the Top Quark at the Tevatron

abstract:
  We investigate the effect that a charged Higgs decay channel for the top
quark has on the signature for top quark pair production at the Tevatron. The
branching ratios for the various multijet and multilepton final states arising
from top pair production are obtained for a wide range of values for tangent
beta and the charged Higgs boson mass. In addition, the effect of the charged
Higgs decay of the top quark on the 2 b-tagged jets and 1 lepton channel is
considered.


title: Higgs Boson with Large Bottom Yukawa Coupling at Tevatron and LHC

abstract:
  We study the discovery reach of the Tevatron and the LHC for detecting a
Higgs boson (h), predicted in composite models of the electroweak symmetry
breaking or in supersymmetric theories, with an enhanced b-quark Yukawa
coupling via p \bar{p} / p p \to b \bbar h (\to b \bbar) + X. Our analysis
shows that studying this process at the Tevatron Run II or the LHC can provide
strong constraints on these models.


title: Supernova Bounds on Neutrino Properties: a mini-review

abstract:
  This talk summarizes our recent work which studied the impact of resonant
neutrino conversion induced by some non-standard neutrino properties beyond
mass and mixing, such as neutrino magnetic moment, lepton-flavor
non-universality as well as flavor changing neutral current interactions in
SUSY models with broken R parity, on supernova physics.


title: Top quark physics at muon and other future colliders

abstract:
  The top quark will be extensively studied at future muon colliders. The
threshold cross section can be measured precisely, and the small beam energy
spread is especially effective at making the measurement useful. We report on
all the activities of the top quark working group, including talks on top quark
physics at other future colliders.


title: Some discussions on strong interaction

abstract:
  Using the gauge field model with massive gauge bosons, we could construct a
new model to describe the strong interaction. In this new quantum
chromodynamics(QCD) model, we will introduce two sets of gluon fields, one set
is massive and another set is massless. Correspondingly, there may exists three
sets of glueballs which have the same spin-parity but have different masses. A
possible new kind of long-range force field is also discussed in this paper.


title: Chiral Quark-Soliton Model

abstract:
  The Chiral Quark-Soliton Model of nucleons is based on two ideas: 1) the
major role of spontaneous chiral symmetry breaking in hadron physics and 2) the
relevance of the large number of colours limit for the real world. In these
lectures I review the theoretical foundations of the model, the physics
involved, and some of applications.
  Contents:
  1. How do we know chiral symmetry is spontaneously broken?
  2. Low-energy limit of QCD from instantons
  2.1. Some of the results
  2.2. Instanton-induced interactions
  2.3. Bosonization
  2.4. Chiral lagrangian
  3. Properties of the chiral lagrangian
  3.1. Derivative expansion and interpolation formula
  3.2. The Wess-Zumino term and the baryon number
  4. The nucleon
  4.1. Physical motivations
  4.2. Nucleon mass: a functional of the pion field
  4.3. Nucleon profile
  4.4. Quantum numbers of baryons
  4.5. Some applications
  4.6. Nucleon structure functions
  5. Conclusions


title:
Higher Twist Distribution Amplitudes of Vector Mesons in QCD: Formalism
  and Twist Three Distributions

abstract:
  We present a systematic study of twist three light-cone distribution
amplitudes of vector mesons in QCD, which is based on conformal expansion and
takes into account meson and quark mass corrections. A complete set of
distribution amplitudes is constructed for rho, omega, K* and phi mesons, which
satisfies all (exact) equations of motion and constraints from conformal
expansion. Nonperturbative input parameters are calculated from QCD sum rules,
including an update of SU(3) breaking corrections in the leading twist
distributions.


title:
1/N_c Corrections to the Hadronic Matrix Elements of Q_6 and Q_8 in K
  --> pi pi Decays

abstract:
  We calculate long-distance contributions to the amplitudes A(K^0 --> pi pi,
I) induced by the gluon and the electroweak penguin operators Q_6 and Q_8,
respectively. We use the 1/N_c expansion within the effective chiral lagrangian
for pseudoscalar mesons. In addition, we adopt a modified prescription for the
identification of meson momenta in the chiral loop corrections in order to
achieve a consistent matching to the short-distance part. Our approach leads to
an explicit classification of the loop diagrams into non-factorizable and
factorizable, the scale dependence of the latter being absorbed in the
low-energy coefficients of the effective theory. Along these lines we calculate
the one-loop corrections to the O(p^0) term in the chiral expansion of both
operators. In the numerical results, we obtain moderate corrections to
B_6^(1/2) and a substantial reduction of B_8^(3/2).


title: Polarized Parton Distributions and QCD Spin Tests at RHIC-BNL

abstract:
  The RHIC facility at BNL will be operating soon, part of the year, as a
polarized proton-proton collider. This will allow the undertaking of a vast
spin physics programme, mainly by the two large detectors PHENIX and STAR. We
review some theoretical aspects of this research programme which will allow,
firstly to improve our present knowledge on polarized quark, gluon and sea
distributions in a nucleon, secondly to perform novel QCD spin tests and
finally, perhaps, to uncover some new physics.


title: Precision Physics at LEP

abstract:
  1 - Introduction
  2 - Small-Angle Bhabha Scattering and the Luminosity Measurement
  3 - Z^0 Physics
  4 - Fits to Precision Data
  5 - Physics at LEP2
  6 - Conclusions


title:
Isospin Fluctuations from Multiple Domains of Disoriented Chiral
  Condensate

abstract:
  We describe some detailed numerical simulations of Disoriented Chiral
Condensates (DCCs), using the chiral lagrangian as a controlled long-wavelength
description. We focus on the possibility of multiple, independently coherent
domains, and investigate the degree to which the DCC signal is attenuated. As
an intermediate step in our analysis we compute the expected number of detector
events in each isospin and momentum channel for a given asymptotic classical
field configuration. We find that for sufficiently large initial field
strengths, the non-linear interactions between domains become important and can
lead to a randomization of isospin orientations. Nevertheless, we argue that
viable signals exist for DCC detection, even in the case of multiple domains
and strong domain-domain interactions. We briefly discuss some long-lived
`pseudo-bound state' configurations which arise at large field strengths and
might be observable in HBT correlations.


title:
Ultra-High Energy Cosmic Rays, Superheavy Long-Living Particles, and
  Matter Creation after Inflation

abstract:
  The highest energy cosmic rays, above the Greisen-Zatsepin-Kuzmin cut-off of
cosmic ray spectrum, may be produced in decays of superheavy long-living
X-particles. We conjecture that these particles may be produced naturally in
the early Universe from vacuum fluctuations during inflation and may constitute
a considerable fraction of Cold Dark Matter. We predict a new cut-off in the
UHE cosmic ray spectrum E_{cut-off} < m_inflaton \approx 10^{13} GeV, the exact
position of the cut-off and the shape of the cosmic ray spectrum beyond the GZK
cut-off being determined by the QCD quark/gluon fragmentation. The Pierre Auger
Project installation might discover this phenomenon.


title: Top Quark at the Upgraded Tevatron to Probe New Physics

abstract:
  This talk is a brief review of the recent studies on probing new physics
through single top quark processes and probing exotic top quark decays at the
upgraded Tevatron.


title: The formation rate of semilocal strings

abstract:
  We carry out three-dimensional numerical simulations to investigate the
formation rate of semilocal strings. We find that the back-reaction of the
gauge fields on the scalar field evolution is substantial, and leads to a
significant formation rate in the parameter regime where the semilocal strings
are classically stable. The formation rate can be as large as a third of that
for cosmic strings, depending on the model parameters.


title: Perturbation theory with unstable fundamental fields

abstract:
  The difficulties of perturbation theory associated with unstable fundamental
fields (such as the lack of exact gauge invariance in each order) are cured if
one constructs perturbative expansion directly for probabilities interpreted as
distributions in kinematic variables. Such an expansion is made possible by the
powerful method of non-Euclidean asymptotic operation [hep-ph/9703424].


title: A Constituent Quark-Meson Model for Heavy-Meson Processes

abstract:
  We describe the effective heavy meson lagrangian for S- and P-wave
heavy-light mesons in terms of a model based on meson-quark interactions, where
mesonic transition amplitudes are represented by diagrams with heavy mesons
attached to loops containing heavy and light constituent quarks. The model is
relativistic and incorporates the heavy quark symmetries. The universal form
factors of the heavy meson transition amplitudes are calculated together with
their slopes and compared to existing data and limits. As further applications
of the model, strong and radiative decays of D* and B* are considered. The
agreement with data is surprisingly good and shows that the model offers a
viable alternative to effective meson lagrangians which require a larger number
of input parameters.


title:
Utility of Galilean Symmetry in Light-Front Perturbation Theory: A
  Nontrivial Example in QCD

abstract:
  Investigations have revealed a very complex structure for the coefficient
functions accompanying the divergences for individual time ($x^+$) ordered
diagrams in light-front perturbation theory. No guidelines seem to be available
to look for possible mistakes in the structure of these coefficient functions
emerging at the end of a long and tedious calculation, in contrast to covariant
field theory. Since, in light-front field theory, transverse boost generator is
a kinematical operator which acts just as the two-dimensional Galilean boost
generator in non-relativistic dynamics, it may provide some constraint on the
resulting structures. In this work we investigate the utility of Galilean
symmetry beyond tree level in the context of coupling constant renormalization
in light-front QCD using the two-component formalism. We show that for each
$x^+$ ordered diagram separately, underlying transverse boost symmetry fixes
relative signs of terms in the coefficient functions accompanying the diverging
logarithms. We also summarize the results leading to coupling constant
renormalization for the most general kinematics.


title:
Search for a heavy magnetic monopole at the Fermilab Tevatron and CERN
  LHC

abstract:
  If a heavy Dirac monopole exists, the light to light scattering below the
monopole production threshold is enhanced due to the strong coupling of
monopoles to photons. This effect could be observable in the collision of
virtual photons at proton colliders. At the Tevatron it will be seen as pair
production of photons with energies 200--400 GeV and roughly compensated
transverse momenta 100--400 GeV/c. This effect could be seen at monopole masses
about 1--2.5 TeV at the upgraded Tevatron and 7.4--19 TeV at LHC depending on
monopole spin.


title: Topological Defects in the Cosmos and Lab

abstract:
  Current theories of particle physics lead to the unavoidable conclusion that
there must have been several phase transitions in the early universe. Further,
in the context of these theories, it is possible that cosmological phase
transitions would have produced topological defects that may be roaming our
heavens today. A finding of these fossils from the early universe would provide
a direct confirmation of the thermal history of the cosmos, insight into
astrophysical phenomena, and, vital information about particle physics. The
elimination of unobserved topological defects provides important constraints on
particle physics and may also suggest novel cosmology. I describe some of the
research on cosmic topological defects and recent efforts to address
cosmological issues in condensed matter systems. (Invited article for
publication in Contemporary Physics.)


title:
Stochastic interpretation of Kadanoff-Baym equations and their relation
  to Langevin processes

abstract:
  In this more pedagogical study we want to elucidate on stochastic aspects
inherent to the (non-)equilibrium real time Green's function description (or
`closed time path Green's function' -- CTPGF) of transport equations, the so
called `Kadanoff-Baym equations'. As a toy model we couple a free scalar boson
quantum field to an exemplaric heat bath with some given temperature T. It will
be shown in detail that the emerging transport equations have to be understood
as the ensemble average over stochastic equations of Langevin type. This
corresponds to the equivalence of the influence functional approach by Feynman
and Vernon and the CTP technique. The former, however, gives a more intuitive
physical picture. In particular the physical role of (quantum) noise and the
connection of its correlation kernel to the Kadanoff-Baym equations will be
discussed. The inherent presence of noise and dissipation related by the
fluctuation-dissipation theorem guarantees that the modes or particles become
thermally populated on average in the long-time limit. For long wavelength
modes with momenta much less than the temperature the emerging wave equation do
behave nearly as classical. On the other hand, a kinetic transport description
can be obtained in the semi-classical particle regime. Including fluctuations,
its form resembles that of a phenomenological Boltzmann-Langevin description.
However, we will point out some severe discrepancies in comparison to the
Boltzmann- Langevin scheme. As a further byproduct we also note how the
occurrence of so called pinch singularities is circumvented by a clear physical
necessity of damping within the one-particle propagator.


title: Left-right asymmetries in polarized lepton-lepton scattering

abstract:
  Several parity violating left-right asymmetries in M\o ller electron-electron
and muon-muon scattering are considered in the context of the electroweak
standard model at tree level in fixed target and collider experiences. We show
that in colliders the asymmetry with only one of the beam polarized is large
enough to compensate the smaller cross section at high energies. We also show
that these asymmetries are very sensitive to a doubly charged vector bilepton
resonance but they are insensitive to scalar ones.


title: A Minimality Condition and Atmospheric Neutrino Oscillations

abstract:
  A structure is proposed for the mass matrices of the quarks and leptons that
arises in a natural way from the assumption that the breaking of SO(10) gauge
symmetry is achieved by the smallest possible set of vacuum expectation values.
This structure explains well many features of the observed spectrum of quarks
and leptons. It reproduces the Georgi-Jarlskog mass relations and postdicts the
charm quark mass in reasonable agreement with data. It also predicts a large
mixing angle between \nu_{\mu} and \nu_{\tau}, as suggested by atmospheric
neutrino data. The mixing angles of the electron neutrino are predicted to be
small.


title: Weak phase $\gamma$ from color-allowed $B \to D K$ rates

abstract:
  The ratios of partial rates for charged B decays to the recently observed
$D^0 K$ mode and to the two $D_{CP}K$ final states (CP = $\pm$) are shown to
constrain the weak phase $\gamma \equiv {\rm Arg} (V_{ub}^*)$. The smaller
color-suppressed rate, providing further information about the phase, can be
determined from these rates alone. Present estimates suggest that, while the
first constraints can already be obtained in a high luminosity e^+e^- B
factory, measuring the color-suppressed rate would require dedicated hadronic B
production experiments.


title: Parametrising the proton structure function

abstract:
  We show that simple parametrisations at small x of the proton structure
function work so well in limited regions of the $(x,Q^2)$ plane because they
are approximately "self-consistent" solutions of the QCD evolution equation.
For a class of them, we predict their $Q^2$ dependence and compare the result
with experimental data.


title: Parity Violating Energy Shifts and Berry Phases in Atoms, I

abstract:
  We present a study of parity (P) violating contributions to the eigenenergies
of stationary systems containing atoms in spatially inhomogeneous external
electric fields. In this context the subtle interplay of P-violation and time
reversal (T) invariance plays an important role. If the entire field
configuration is chosen to exhibit chirality the energies are in general
shifted by pseudoscalar contributions which change sign under a planar
reflection of the field. To calculate the effects we use the standard model of
elementary particle physics where the P-odd interaction arises through the
exchange of Z-bosons between the quarks in the nucleus and the atomic
electrons. We consider in detail hydrogen-like systems in unstable levels of
principal quantum number n=2. The nominal order of P-violating effects is
10^-5...10^-9 Hz which is determined by the mixing of the 2S_1/2 and 2P_1/2
states. However we point out that it is possible to enhance the P-violating
energy shifts dramatically! Instead of energy shifts linear in the P-violation
parameters we get then shifts proportional to the square root of these
parameters. Numerically we find such energy shifts to be of order 10^-5...1 Hz.
Application of our technique to hydrogen-like atoms with a nucleus of spin
I=1/2 yields P-violating energy shifts which are very sensitive to the nuclear
spin dependent P-odd force, which receives a rather large contribution from the
polarized strange quark density in polarized nuclei. Thus, a measurement of
these energy shifts could provide an important tool to elucidate nuclear
properties connected to the so called ``spin crisis''. We also present a method
for treating degenerate perturbation theory which combines advantages of both,
Kato's and Bloch's methods.


title: Wigner functions of essentially nonequilibrium systems

abstract:
  The aim of the article is to discuss the S-matrix interpretation of
perturbation theory for the Wigner functions generating functional at a finite
temperature. For sake of definiteness, fruitful from pedagogical point of view,
the concrete problem from particle physics of high-temperature initial states
dissipation into cold one is considered from experimental and theoretical
points of view. The temperature is introduced in the theory by typical for the
microcanonical description way. The perturbation theory contains two-
temperature (of initial and final states) Green functions. Two possible
boundary conditions are considered. One of them is usual in a field theory
vacuum boundary condition. Corresponding generating functional of Wigner
functions can be used in the particle physics. Another type of the boundary
condition assumes that the system under consideration is in environment of the
black-body radiation. This leads to the usual in statistics
Kubo-Martin-Schwinger boundary condition at the equilibrium (one-temperature)
limit. The comparison of the S-matrix approach with Schwinger-Keldysh real-time
finite-temperature field theory and with nonstationary statistical operator
approach of Zubarev are considered. The range of applicability of the
finite-temperature description of dissipation processes is shown.


title: Derivative expansions of real-time thermal effective actions

abstract:
  We use a generalised real-time path formalism with properly regularised
propagators based on Le Bellac and Mabilat \cite{belmab} and calculate the
effective potential and the higher order derivative terms of the effective
action in the case of real scalar fields at finite temperature. We consider
time-dependent fields in thermal equilibrium and concentrate on the quadratic
part of the expanded effective action which has been associated with problems
of non-analyticity at the zero limits of the four external momenta at finite
temperature. We derive the effective potential and we explicitly show its
independence of the initial time of the system when we include both paths of
our time contour. We also derive the second derivative in the field term and
recover the Real Time (RTF) and the Imaginary Time Formalism (ITF) and show
that the divergences associated with the former are cancelled as long as we set
the regulators zero in the end. Using an alternative method we write the field
in its Taylor series form and we first derive RTF and ITF in the appropriate
limits, check the analyticity properties in each case and do the actual time
derivative expansion of the field up to second order in the end. We agree with
our previous results and discuss an interesting term which arises in this
expansion. Finally we discuss the initial time-dependence of the quadratic part
of the effective action before the expansion of the field as well as of the
individual terms after the expansion.


title: The Top Quark and Higgs Boson at Hadron Colliders

abstract:
  To provide context for discussions of experiments at future muon colliders, I
survey what is known and what will be known about the top quark and the Higgs
boson from experiments at hadron colliders.


title: The possible $\Sigma^0$-$\Lambda$ mixing in QCD sum rules

abstract:
  We calculate the on-shell $\Sigma^0$-$\Lambda$ mixing parameter $\theta$ with
the method of QCD sum rule. Our result is $\theta (m^2_{\Sigma^0}) =(-)(0.5\pm
0.1)$MeV. The electromagnetic interaction is not included.


title:
The $\Omega$ and $\Sigma^0$-$\Lambda$ transition magnetic moments in QCD
  sum rules

abstract:
  The method of QCD sum rules in the presence of external elctromagnetic fields
is used to calculate the $\Omega$ magnetic moment $\mu_{\Omega^-}$ and
$\Sigma^0$-$\Lambda$ transition magnetic moment $\mu_{\Sigma^0\Lambda}$, with
the susceptibilities obtained previously from the study of octet baryon
magnetic moments. The results $\mu_{\Omega^-}=-1.92\mu_N$ and
$\mu_{\Sigma^0\Lambda}=1.5\mu_N$ are in good agreement with the recent
experimental data.


title:
Constraints on R parity and B violating couplings in gauge-mediated
  supersymmetry breaking models

abstract:
  We consider the proton decay involving a light gravitino or axino in
gauge-mediated supersymmetry breaking models to derive constraints on the $R$
parity and baryon number violating Yukawa couplings. Bounds on all nine
coupling constants are obtained by considering the decay amplitudes at one-loop
order.


title: An SU(3) model for octet baryon and meson fragmentation

abstract:
  The production of the octet of baryons and mesons in e^+ e^- collisions is
analysed, based on considerations of SU(3) symmetry and a simple model for
SU(3) symmetry breaking in fragmentation functions. All fragmentation
functions, D_q^h(x, Q^2), describing the fragmentation of quarks into a member
of the baryon octet (and similarly for fragmentation into members of the meson
octet) are expressed in terms of three SU(3) symmetric functions, \alpha(x,
Q^2), \beta(x, Q^2), and \gamma(x, Q^2). With the introduction of an SU(3)
breaking parameter, \lambda, the model is successful in describing
hadroproduction data at the Z pole. The fragmentation functions are then
evolved using leading order evolution equations and good fits to currently
available data at 34 GeV and at 161 GeV are obtained.


title: Pairs in the light-front and covariance

abstract:
  The electromagnetic current of bound systems in the light-front is
constructed in the Breit-Frame, in the limit of momentum transfer
$q^+=(q^0+q^3)$ vanishing. In this limit, the pair creation term survives and
it is responsible for the covariance of the current. The pair creation term is
computed for the $j^+$ current of a spin one composite particle in the
Breit-frame. The rotational symmetry of $j^+$ is violated if the pair term is
not considered.


title:
Two body non-leptonic $\Lambda_b$ decays in quark model with
  factorization ansatz

abstract:
  The two body non-leptonic $\Lambda_b$ decays are analyzed in factorization
approximation, using quark model, $\xi = 1 / N_c$ as a free parameter. It is
shown that the experimental branching ratio for $\Lambda_b \longrightarrow
\Lambda {J/\psi}$ restricts $\xi$ and this ratio can be understood for a value
of $\xi$ which lies in the range $ 0 \leq \xi \leq 0.5 $ suggested by two body
B meson decays. The branching ratios for $\Lambda_b \longrightarrow \Lambda_{c}
D^*_s(D_s) $ are predicted to be larger than the previous estimates. Finally it
is pointed that CKM-Wolfenstein parameter $\rho^2 + \eta^2$, where $\eta$ is CP
phase, can be determined from the ratio of widths of $\Lambda_b \longrightarrow
\Lambda \bar{D}$ and $\Lambda_b \longrightarrow \Lambda {J/\psi}$ or that of
$\Lambda_b \longrightarrow p D_s$ and $\Lambda_b \longrightarrow \Lambda_c D_s$
independent of the parameter $\xi$.


title:
Analysis of preliminary data on $e^+e^-\to\phi\to\gamma
  f_0(980)\to\gamma\pi^0\pi^0$ reaction

abstract:
  We perform the analysis of the preliminary data on $e^+e^-\to\phi\to\gamma
f_0(980)\to\gamma\pi^0\pi^0$ reaction simultaneously with the data on $\pi\pi$
scattering and reactions $J/\psi\to\phi\pi^+\pi^-$ and
$K^-p\to\pi^+\pi^-(\Lambda,\Sigma)$. It is found that the $f_0(980)$ meson mass
$m_{f_0}=950$ MeV and $B(\phi\to\gamma
f_0\to\gamma\pi^0\pi^0)\simeq1\cdot10^{-4}$.


title: Neutrino Mass Matrix, Mixing and Oscillation

abstract:
  We investigate the phenomenological consequences of lepton mass matrices
originated from the family permutation symmetry and its suitable breakings.
Adopting the recently proposed new mass matrix for the charged lepton mass
matrix and the Majorana neutrino mass matrix considered before, we find that
the resulting lepton flavor mixing matrix is consistent with the current data
on various type of neutrino oscillation experiments except the Chlorine data
and LSND measurement and that three neutrinos are almost degenerate in mass.
Numerically the three neutrinos can account for about 50% of the hot dark
matter(HDM) when the neutrino mass matrix is constrained by the small angle MSW
solution for the solar neutrino problem, atmospheric neutrino data of the
Super-Kamiokande group, and the limitation on the electron-type neutrino mass
due to non-observation of neutrino-less double beta decays.


title: Yukawa-coupling corrections to scalar quark decays

abstract:
  Heavy squark decays into top and charginos or neutralinos could be an
unexpected source of top quarks at hadron colliders. A detailed treatment of
these processes is necessary for a reliable calculation of both the top quark
production cross-section and the standard top quark branching ratio in the
MSSM. Along this line we compute the electroweak corrections to the sbottom
decays sbottom_a --> chargino_i top within the Yukawa coupling approximation.
The calculation of these higher order contributions requires renormalization of
both the bottom squark mixing angle and of tan(beta). This type of corrections
gives the leading order electroweak effects at low and high tan(beta).


title: New Class of Quark Mass Matrices and the Flavor Mixing Matrix

abstract:
  We discuss a new general class of mass matrix ansatz that respects the
fermion mass hierarchy and calculability of the flavor mixing matrix. This is a
generalization of the various specific forms of the mass matrix that is
obtained by successive breaking of the maximal permutation symmetry. By
confronting the experimental data, a large class of the mass matrices are shown
to survive, while certain specific cases are phenomenologically ruled out.


title:
Bottom-up approach to B-parameter in minimal supersymmetric standard
  model

abstract:
  We study $\mu$ and $B$-parameters in the minimal supersymmetric standard
model (MSSM) based on the radiative electroweak symmetry breaking scenario
using $\lq\lq$bottom-up" approach and show how useful our approach is to select
a phenomenologically viable model beyond the MSSM under the assumption that the
underlying theory is a string model or a gauge-Yukawa unified gauge model.


title: Inflation and B-L breaking scale

abstract:
  Inflation arises in supersymmetric grand unified theories (susy GUTs) without
fine tuning and cosmic strings usually form at the end of inflation. Hence both
strings and inflation contribute to the density perturbations in the very early
universe which lead to structure formation and to CMB anisotropies. This may
give us a hint as to the $B-L$ breaking scale.


title: Leptogenesis with cosmic strings

abstract:
  A new scenario for baryogenesis is described. The basic idea is that theories
beyond the standard model which contain a ${\rm U}(1)_{B-L}$ gauge symmetry,
where $B$ and $L$ are respectively baryon and lepton numbers, predict the
existence of $B-L$ cosmic strings with right-handed neutrinos trapped as
transverse zero modes. Cosmic string loops loose their energy via gravitational
radiation and rapidly decay releasing these right-handed neutrinos. These decay
into lepton and electroweak Higgs boson producing an initial lepton asymmetry.
This lepton asymmetry is then converted into a baryon asymmetry via sphaleron
transitions. The minimal extension of the standard model and the minimal grand
unified theory for which this scenario works are respectively ${\rm SU}(3)_c
\times {\rm SU}(2)_L \times {\rm U}(1)_R \times {\rm U}(1)_{B-L}$ and SO(10).


title: Predictions from an Anomalous U(1) Model of Yukawa Hierarchies

abstract:
  We present a supersymmetric standard model with three gauged Abelian
symmetries, of a type commonly found in superstrings. One is anomalous, the
other two are $E_6$ family symmetries. It has a vacuum in which only these
symmetries are broken by stringy effects. It reproduces all observed quark and
charged lepton Yukawa hierarchies, and the value of the Weinberg angle. It
predicts three massive neutrinos, with mixing that can explain both the small
angle MSW effect, and the atmospheric neutrino anomaly. The Cabibbo angle is
expressed in terms of the gauge couplings at unification. It conserves
R-parity, and proton decay is close to experimental bounds.


title:
Diffusion and Decoherence of Squarks and Quarks During the Electroweak
  Phase Transition

abstract:
  To estimate the diffusion constant $D$ of particles in a plasma, we develop a
method that is based on the mean free path $\lambda$ for scatterings with
momentum transfer $q >~ T$. Using this method, we estimate $\lambda$ and $D$
for squarks and quarks during the electroweak phase transition. Assuming that
Debye and magnetic screening lengths provide suitable infrared cutoffs, our
calculations yield $\lambda <~ 18/T$ and $D <~ 5/T$ for both squarks and
quarks. Our estimate of $\lambda$ suggests that suppressions of charge
transport due to decoherence of these strongly interacting particles during the
electroweak phase transition are not severe and that these particles may
contribute significantly to electroweak baryogenesis.


title: Flavour-conserving oscillations of Dirac-Majorana neutrinos

abstract:
  We analyze both chirality-changing and chirality-preserving transitions of
Dirac-Majorana neutrinos. In vacuum, the first ones are suppressed with respect
to the others due to helicity conservation and the interactions with a
(``normal'') medium practically does not affect the expressions of the
probabilities for these transitions, even if the amplitudes of oscillations
slightly change. For usual situations involving relativistic neutrinos we find
no resonant enhancement for all flavour-conserving transitions. However, for
very light neutrinos propagating in superdense media, the pattern of
oscillations $\nu_L \to \nu^C_L$ is dramatically altered with respect to the
vacuum case, the transition probability practically vanishing. An application
of this result is envisaged.


title: Astrophysical Aspects of Quark-Gluon Plasma

abstract:
  This M.Sc. thesis in Engineering Physics is an overview of the present theory
of quark-gluon plasma (QGP) as well as an analysis of the stability criterion
for possible stable cosmic QGP objects left over from the quark-hadron
transition in the early Universe. It covers fundamental ideas of the formation
and decay of the plasma, including the standard model, QCD, and the MIT bag
model. I discuss the equation of state of a QGP and the possible signatures for
a plasma created in heavy-ion collisions. Astrophysical aspects of QGP are put
forward, including compact stars and the quark-hadron transition in the early
Universe. The possible role of QGP objects as cosmic dark matter is mentioned.
The analytic part is an investigation of possible stability among cosmic QGP
objects from the early Universe. A model is suggested where a pressure balance
makes a QGP stable against gravitational contraction and hadronization. The
mass/radius relationship for stability also forbids a direct gravitational
collapse. Finally, the possibility of stable cosmic QGP objects is critically
discussed.


title:
The Low Energy Expansion for Pion-Pion Scattering and Crossing Symmetry
  in Dispersion Relations

abstract:
  We show that a suitable setting for comparison of the low-energy
representation for pion-pion scattering amplitudes, with dispersive
representation for these amplitudes, is provided by certain manifestly crossing
symmetric dispersion relations. We begin with a discussion of fixed-t
dispersion relations and discuss the origin of crossing constraints that arise
in this context when we consider resonance saturation with certain $l\geq 2$
states. We demonstrate that the approach advocated here does not require us to
enforce such constraints. Our results are contrasted with those from fixed-t
dispersion relations. We finally discuss the numerical import of our results.


title: Preon Trinity

abstract:
  We present a new minimal model for the substructure of all known quarks,
leptons and weak gauge bosons, based on only three fundamental and stable
spin-1/2 preons. As a consequence, we predict three new quarks, three new
leptons, and six new vector bosons. One of the new quarks has charge $-4e/3$.
The model explains the apparent conservation of three lepton numbers, as well
as the so-called Cabibbo-mixing of the $d$ and $s$ quarks, and predicts
electromagnetic decays or oscillations between the neutrinos $\bar{\nu}_{\mu}$
($\nu_{\mu}$) and $\nu_e$ ($\bar{\nu}_e$). Other neutrino oscillations, as well
as rarer quark mixings and CP violation can come about due to a small
quantum-mechanical mixing of two of the preons in the quark and lepton wave
functions.


title:
Quasi degenerate Neutrino Masses with Universal Strength Yukawa
  Couplings

abstract:
  A simple ansatz is proposed for neutrino and charged lepton mass matrices,
within the framework of universal strength for Yukawa couplings. In this
framework all Yukawa couplings have equal moduli and the flavour dependence is
only in their phases. We take into account the solar neutrino deficit and the
atmospheric neutrino anomaly, assuming three neutrino families only. The ansatz
leads in a natural way to small mixing involving neutrinos of quasi degenerate
masses, as required to explain the solar neutrino deficit in the nonadiabatic
MSW solution, while having the large mixing necessary to explain the
atmospheric neutrino anomaly.


title: Hadronic Contributions to the Muon Lifetime

abstract:
  Hadronic corrections to the muon lifetime are calculated in the Fermi theory
in the presence of QED using dispersion relations. The result, after
convolution of hadron data with the calculated perturbative kernel is
  Delta Gamma_had = -Gamma_0(alpha/pi)^2(0.042)
  where Gamma_0 is the tree-level width. The results are also used to obtain
the corrections to the muon lifetime coming from virtual muon and tau loops
  Delta Gamma_muon
  = Gamma_0(alpha/pi)^2[(16987/576)-(85/36)zeta(2)-(64/3)zeta(3)]
  = -Gamma_0(alpha/pi)^2(0.0364333)
  Delta Gamma_tau = -Gamma_0(alpha/pi)^2)(0.00058)


title:
Concluding Remarks - International Symposium on ``QCD Corrections and
  New Physics", 1997, Hiroshima, Japan -

abstract:
  This is a report of the concluding talk presented at the International
Symposium on QCD Corrections and New Physics which was held during October
27-29, 1997 at Mielparque Hiroshima, Hiroshima, Japan. The report will be
published in the Conference Proceedings.


title: The Search for Higgs Bosons of Minimal Supersymmetry at the LHC

abstract:
  The prospects for discovering neutral Higgs bosons in the minimal
supersymmetric model (MSSM) and in the minimal supergravity model at the LHC
are investigated. Two special discovery channels are discussed: (i) the decay
mode of the MSSM CP-odd Higgs boson into photon pairs, and (ii) the decays of
neutral Higgs bosons into muon pairs in the MSSM as well as in the minimal
supergravity model.


title:
About direct Dark Matter detection in Next-to-Minimal Supersymmetric
  Standard Model

abstract:
  Direct dark matter detection is considered in the Next-to-Minimal
Supersymmetric Standard Model (NMSSM). The effective neutralino-quark
Lagrangian is obtained and event rates are calculated for the Ge-73 isotope.
Accelerator and cosmological constraints on the NMSSM parameter space are
included. By means of scanning the parameter space at the Fermi scale we show
that the lightest neutralino could be detected in dark matter experiments with
sizable event rate.


title: Searching for K_L -> pi^0 nu nubar at a Phi-factory

abstract:
  The perspectives of a search for the rare decay $K_L\to\pi^0\nu\bar{\nu}$ at
a Phi-factory are discussed. After a general analysis, we focus on the
realistic case of KLOE and DAFNE, showing that limits of the order of $10^{-9}$
on BR($K_L\to\pi^0\nu\bar{\nu}$) are achievable in the next few years. We also
discuss the theoretical implications of this kind of measurements.


title: Gauge invariance and hadron structure

abstract:
  We prove that the {\em gauge dependent} gluon spin, gluon and quark orbital
angular momenta operators have {\em gauge invariant} expectation values on
hadron states with {\em definite} momentum and polarization, therefore the
conventional decomposition of nucleon spin into contributions from the spin and
orbital angular momentum of quark and gluon is {\em gauge independent}. Similar
conclusions apply to the {\em gauge dependent} quark momentum and kinetic
energy operators, and accordingly nucleon momentum and mass structures.


title: How does baryon magnetic moment relate to its spin structure

abstract:
  A model independent, field theoretical relation between baryon magnetic
moment and its spin structure is derived and it is explained why constituent
quark model is a good approximation in describing baryon magnetic moments.


title: The Non-perturbative Effect on $R=\sigma_L /\sigma_T$ from QCD Vacuum

abstract:
  We investigate the non-perturbative effects on the ratio $R=\sigma_L
/\sigma_T$ in lepton-nucleon deep inelastic scattering by taking into account
the lowest dimensional condensate contributions from the QCD vacuum. By
combining conventional perturbative QCD corrections and the Georgi- Politzer
target-mass effects with the non-perturbative effects from the QCD vacuum, we
give a good description of the $Q^2$ and $x$ dependences of $R$ in comparison
with the recent experimental data.


title: A model for a dynamically induced large CP-violating phase

abstract:
  Assuming a new interaction with a $\theta$ term for the third generation of
quarks, a value of $\theta$ different from zero dynamically induces the top-
bottom mass splitting and a large CP-violating phase.


title: Scale evolution of nuclear parton distributions

abstract:
  Using the NMC and E665 nuclear structure function ratios $F_2^A/F_2^D$ and
$F_2^A/F_2^{C}$ from deep inelastic lepton-nucleus collisions, and the E772
Drell--Yan dilepton cross sections from proton-nucleus collisions, and
incorporating baryon number and momentum sum rules, we determine nuclear parton
distributions at an initial scale $Q_0^2$. With these distributions, we study
QCD scale evolution of nuclear parton densities. The emphasis is on small
values of $x$, especially on scale dependence of nuclear shadowing. As the main
result, we show that a consistent picture can be obtained within the leading
twist DGLAP evolution, and in particular, that the calculated $Q^2$ dependence
of $F_2^{Sn}/F_2^{C}$ agrees very well with the recent NMC data.


title: Ultra High Energy Cosmic Rays

abstract:
  The current status of Ultra High Energy Cosmic Rays (UHECR) is reviewed, with
emphasis given to theoretical interpretation of the observed events. The
galactic and extragalactic origin, in case of astrophysical sources of UHE
particles, have the problems either with acceleration to the observed energies
or with the fluxes and spectra. Topological defects can naturally produce
particles with energies as observed and much higher, but in most cases fail to
produce the observed fluxes. Cosmic necklaces and monopole-antimonopole pairs
are identified as most plausible sources, which can provide the observed flux
and spectrum. The relic superheavy particles are shown to be clustering in the
Galactic halo, producing UHECR without Greisen-Zatsepin-Kuzmin cutoff. The
Lightest Supersymmetric Particles are discussed as UHE carriers in the
Universe.


title: CP violating angular asymmetries of b and bbar quarks in e+e- -> t tbar

abstract:
  We obtain analytical formulae for the cross section and the angular
distributions of the b(bbar) quarks in the process e+e- -> t tbar, with t -> W+
b (tbar -> W- bbar) assuming CP violation in the \gamma t tbar and Z t tbar
vertices. We present CP violating asymmetries, which measure separately the
real and imaginary parts of the electroweak dipole moment form factors of the
top, d^{\gamma}(s) and d^{Z}(s). We give a numerical analysis of these
asymmetries within the Minimal Supersymmetric Standard Model with complex
parameters. They turn out to be of order <= 10^{-3}.


title:
On the Topological Term in the String Representation of the Wilson Loop
  in the Dilute Instanton Gas

abstract:
  A topological term related to the number of self-intersections of the string
world-sheet is shown to emerge in the string representation of the Wilson loop
in the dilute instanton gas. The coupling constant of this term occurs to be
proportional to the topological charge of the instanton gas under
consideration.


title: Semileptonic decays and axial-vector constants of the octet baryons

abstract:
  %auto-ignore The paper has been withdrawn by authors. The completely revised
version can be found under the following preprint-no: hep-ph/9910282.


title: Supersymmetry vis-a-vis Muon Colliders

abstract:
  The potential of muon colliders to study a low-energy supersymmetry is
addressed in the framework of the minimal supergravity model, whose predictions
are first briefly surveyed. Foremost among the unique features of a muon
collider is s-channel production of Higgs bosons, by which Higgs boson masses,
widths, and couplings can be precisely measured to test the predictions of
supersymmetry. Measurements of the threshold region cross sections of W^+ W^-,
t t-bar, Zh, chargino pairs, slepton and sneutrino pairs will precisely
determine the corresponding masses and test supersymmetric radiative
corrections. At the high-energy frontier a 3 to 4 TeV muon collider is ideally
suited to study heavy scalar supersymmetric particles.


title: Hierarchical Quark Mass Matrices

abstract:
  I define a set of conditions that the most general hierarchical Yukawa mass
matrices have to satisfy so that the leading rotations in the diagonalization
matrix are a pair of (2,3) and (1,2) rotations. In addition to Fritzsch
structures, examples of such hierarchical structures include also matrices with
(1,3) elements of the same order or even much larger than the (1,2) elements.
Such matrices can be obtained in the framework of a flavor theory. To leading
order, the values of the angle in the (2,3) plane (s_{23}) and the angle in the
(1,2) plane (s_{12}) do not depend on the order in which they are taken when
diagonalizing. We find that any of the Cabbibo-Kobayashi-Maskawa matrix
parametrizations that consists of at least one (1,2) and one (2,3) rotation may
be suitable. In the particular case when the s_{13} diagonalization angles are
sufficiently small compared to the product s_{12}s_{23}, two special CKM
parametrizations emerge: the R_{12}R_{23}R_{12} parametrization follows with
s_{23} taken before the s_{12} rotation, and vice versa for the
R_{23}R_{12}R_{23} parametrization.


title:
Measurements of the Proton and Deuteron Spin Structure Functions g1 and
  g2

abstract:
  Measurements are reported of the proton and deuteron spin structure functions
g1 at beam energies of 29.1, 16.2, and 9.7 GeV and g2 at a beam energy of 29.1
GeV. The integrals of g1 over x have been evaluated at fixed Q**2 = 3
(GeV/c)**2 using the full data set. The Q**2 dependence of the ratio g1/F1 was
studied and found to be small for Q**2 > 1 (GeV/c)**2. Within experimental
precision the g2 data are well-described by the Wandzura-Wilczek twist-2
contribution. Twist-3 matrix elements were extracted and compared to
theoretical predictions. The asymmetry A2 was measured and found to be
significantly smaller than the positivity limit for both proton and deuteron
targets. A2 for the proton is found to be positive and inconsistent with zero.
Measurements of g1 in the resonance region show strong variations with x and
Q**2, consistent with resonant amplitudes extracted from unpolarized data.
These data allow us to study the Q**2 dependence of the first moments of g1
below the scaling region.


title: Supersymmetric D-term Inflation, Reheating and Affleck-Dine Baryogenesis

abstract:
  The phenomenology of supersymmetric models of inflation, where the
inflationary vacuum energy is dominated by D-terms of a U(1), is investigated.
Particular attention is paid to the questions of how to arrange for sufficient
e-folds of inflation to occur, what kind of thermal history is expected after
the end of inflation, and how to implement successful baryogenesis. Such models
are argued to require a more restrictive symmetry structure than previously
thought. In particular, it is non-trivial that the decays of the fields driving
D-inflation can reheat the universe in such a way as to avoid the strong
gravitino production constraints. We also show how the initial conditions for
Affleck-Dine baryogenesis can arise in these models and that the simplest flat
directions along which baryon number is generated can often be ruled out by the
constraints coming from decoherence of the condensate in a hot environment. At
the end, we find that successful reheating and baryogenesis can take place in a
large subset of D-inflationary models.


title: Do quark masses run?

abstract:
  The importance of measuring the b-quark mass at different scales is
emphasized. The recent next-to-leading order calculation of three jet heavy
quark production at LEP and its use to measure $m_b(m_Z)$ is discussed.


title:
The Spectrum of the Hybrid Mesons with Heavy Quarks from the B.S.
  Equation

abstract:
  We construct the B.S. equation for the hybrid mesons under instantaneous
approximation. The kernel is chosen as the sum of an one-gluon exchange
potential and a linear confining potential. The equations are solved by
numerical method, and the spectrum of hybrid mesons $b\bar{b}g$ and $c\bar{c}g$
are obtained.


title: Final State Interaction Phases in $ B \to K \pi$ Decay Amplitudes

abstract:
  A simple Regge pole model for $K\pi$ scattering explains the large $e^{i
\delta}$ between isospin amplitudes which is observed at the D meson mass
($\delta \approx \pi/2$). It predicts $\delta \approx 14^{\circ}- 20^{\circ}$
at the B mass. Implications for ($B \to K \pi$) decays and extensions of the
model to other two-body decay channels are briefly discussed.


title: Evolution Equations for Higher Moments of Angular Momentum Distributions

abstract:
  Based on a sumrule for the nucleon spin we expand quark and gluon orbital
angular momentum operators and derive an evolution matrix for higher moments of
the corresponding distributions. In combination with the spin-dependent
DGLAP-matrix we find a complete set of spin and orbital angular momentum
evolution equations.


title: t --> W+ b and t --> H+ b at the quantum level in the MSSM

abstract:
  We compare the standard top quark decay and the charged Higgs decay of the
top quark, t --> W+ b and t --> H+ b, at the quantum level in the MSSM. While
the SUSY loop corrections to the standard top quark decay are only of a few
percent, it turns out that t --> H+ b is a most promising candidate for
carrying large quantum SUSY signatures. As a result, the (tan(beta), M_{H+-})
exclusion plots presented by the CDF Collaboration should be thoroughly revised
in the light of the MSSM.


title:
Search for fourth generation quarks and leptons at the Fermilab Tevatron
  and CERN Large Hadron Collider

abstract:
  If next generations of heavy quarks and leptons exist within the standard
model (SM), they can manifest themselves in Higgs boson production at the
Tevatron and the LHC, before being actually observed. This generation leads to
an increase of the Higgs boson production cross section via gluon fusion at
hadron colliders by a factor 6-9. So, the study of this process at the Tevatron
and LHC can finally fix the number of generations in the SM. Using the $WW^*$
Higgs boson decay channel, the studies at the upgraded Tevatron will answer the
question about the next generation for mass values 135 GeV $\lsim M_H\lsim 190$
GeV. Studying the $\tau\bar{\tau}$ channel we show its large potential for the
study of the Higgs boson at the LHC even in the standard case of three
generations. At the Tevatron, studies in this channel could explore the mass
range 110-140 GeV.


title: Matching at one loop for the four-quark operators in NRQCD

abstract:
  The matching coefficients for the four-quark operators in NRQCD (NRQED) are
calculated at one loop using dimensional regularization for ultraviolet and
infrared divergences. The matching for the electromagnetic current follows
easily from our results. Both the unequal and equal mass cases are considered.
The role played by the Coulomb infrared singularities is explained in detail.


title: Higher twists in deep inelastic scattering

abstract:
  We perform an exploratory study of higher twist contributions to deep
inelastic scattering. We estimate the size of two major sources of higher
twist, namely absorptive corrections and the vector meson dominance (VMD)
contribution. We find that they give a sizeable higher twist component of F_2.
For example at x = 0.01 it is about 8% (17%) at Q^2 = 10 GeV^2 (4 GeV^2),
reaching up to 27% at x = 10^{-4} and Q^2 = 4 GeV^2. At the smaller x value the
largest contribution comes from absorptive corrections, while at the larger
values of x the VMD term dominates.


title: Higgs mass saturation effect and the LHC discovery potential

abstract:
  In view of recent perturbative and nonperturbative evidence that the peak of
the Higgs resonance saturates as the coupling increases, we examine the
potential of the future Large Hadron Collider to discover a heavy Higgs
resonance by gluon fusion.


title: Narrow Technihadron Production at the First Muon Collider

abstract:
  In modern technicolor models, there exist very narrow spin-zero and spin-one
neutral technihadrons---$pi^0_T$, $rho^0_T$ and $omega_T$---with masses of a
few 100 GeV. The large coupling of $\pi^0_T$ to $\mu^+\mu^-$, the direct
coupling of $rho^0_T$ and $omega_T$ to the photon and $Z^0$, and the superb
energy resolution of the First Muon Collider may make it possible to resolve
these technihadrons and produce them at extraordinarily large rates.


title:
New Constraints on Dispersive Form Factor Parameterizations from the
  Timelike Region

abstract:
  We generalize a recent model-independent form factor parameterization derived
from rigorous dispersion relations to include constraints from data in the
timelike region. These constraints dictate the convergence properties of the
parameterization and appear as sum rules on the parameters. We further develop
a new parameterization that takes into account finiteness and asymptotic
conditions on the form factor, and use it to fit to the elastic \pi
electromagnetic form factor. We find that the existing world sample of timelike
data gives only loose bounds on the form factor in the spacelike region, but
explain how the acquisition of additional timelike data or fits to other form
factors are expected to give much better results. The same parameterization is
seen to fit spacelike data extremely well.


title: Real-time Relaxation and Kinetics in Hot Scalar QED: Landau Damping

abstract:
  The real time evolution of field condensates with soft length scales
k^{-1}>(eT)^{-1} is solved in hot scalar electrodynamics, with a view towards
understanding relaxational phenomena in the QGP and the electroweak plasma. We
find that transverse gauge invariant non-equilibrium expectation values of
fields relax via {\em power laws} to asymptotic amplitudes that are determined
by the quasiparticle poles. The long time relaxational dynamics and relevant
time scales are determined by the behaviour of the retarded self-energy not at
the small frequencies, but at the Landau damping thresholds. This explains the
presence of power laws and not of exponential decay. Furthermore, we derive the
influence functional, the Langevin equation and the fluctuation-dissipation
theorem for the soft modes, identifying the correlation functions that emerge
in the classical limit. We show that a Markovian approximation fails to
describe the dynamics {\em both} at short and long times. We also introduce a
novel kinetic approach that goes beyond the standard Boltzmann equation and
incorporates off-shell processes and find that the distribution function for
soft quasiparticles relaxes with a power law through Landau damping. We also
find an unusual dressing dynamics of bare particles and anomalous (logarithmic)
relaxation of hard quasiparticles.


title: Coupling Constants Evolution in a Universal Seesaw Mass Matrix Model

abstract:
  Stimulated by a universal seesaw mass matrix model which can successfully
give quark masses and CKM matrix elements in terms of charged lepton masses,
the evolution of the seesaw mass matrices is investigated. Especially, an
investigation is made as to whether the evolution can constrain the necessary
intermediate scales in these types of models and its viability.


title: QCD Running Coupling: Freezing Versus Enhancement in the Infrared Region

abstract:
  We discuss whether or not "freezing" of the QCD running coupling constant in
the infrared region is consistent with the Schwinger -- Dyson (SD) equations.
Since the consistency of the "freezing" was not found, the conclusion is made
that the "analytization" method does not catch an essential part of
nonperturbative contributions. Proceeding from the results on consistency of
the infrared enhanced behaviour of the gluon propagator with SD equations, the
running coupling constant is modified taking into account the minimality
principle for the nonperturbative contributions in the ultraviolet region and
convergence condition for the gluon condensate. It is shown that the
requirements of asymptotic freedom, analyticity, confinement and the value of
the gluon condensate are compatible in the framework of our approach.
Possibilities to find an agreement of the enhanced behaviour of the running
coupling constant with integral estimations in the infrared region are also
discussed.


title: The Perturbative QCD Potential and the ttbar Threshold

abstract:
  We include the full second-order corrections to the static QCD potential in
the analysis of the ttbar threshold cross section. There is an unexpectedly
large difference between the QCD potential improved by the
renormalization-group equation in momentum space and the potential improved by
the renormalization-group equation in coordinate space. This difference remains
even at a fairly short distance 1/r \simeq 100 GeV and its origin can be
understood within perturbative QCD. We scrutinize the theoretical uncertainties
of the QCD potential in relation to the ttbar threshold cross section. In
particular there exists a theoretical uncertainty which limits our present
theoretical accuracy of the ttbar threshold cross section at the peak to be not
better than 6% within perturbative QCD.


title: QCD Sum Rule Determination of $\alpha(M_Z)$ with Minimal Data Input

abstract:
  We present the results of a new evaluation of the running fine structure
constant $\alpha$ at the scale of the $Z$ mass in which the role of the
$e^+e^-$ annihilation input data needed in this evaluation is minimized. This
is achieved by reducing the weight function $M_Z^2/(s(M_Z^2-s))$ in the
dispersion integral over the $e^+e^-$ annihilation data by subtracting a
polynomial function from the weight function which mimics its energy dependence
in given energy intervals. In order to compensate for this subtraction the same
polynomial weight integral is added again but is now evaluated on a circular
contour in the complex plane using QCD and global duality. For the hadronic
contribution to the shift in the fine structure constant we obtain
$\Delta\alpha^{(5)}_{\rm had}=(277.6\pm 4.1)\cdot 10^{-4}$. Adding in the
leptonic and top contributions our final result is $\alpha(M_Z)^{-1}=128.925\pm
0.056$.


title:
On search for a new light gauge boson from $\pi^{0}(\eta)\to\gamma + X$
  decays in neutrino experiments

abstract:
  It is shown that a new light gauge boson $X$ which might be produced in the
decays of pseudoscalar mesons $\pi^{0}(\eta)\to\gamma + X$ could be effectively
searched for in neutrino experiments via the Primakoff effect, in the process
of $X + Z\to \pi^{0}(\eta) + Z$ conversion in the external Coulomb field of a
nucleus. An estimate of the $X\to \pi^{0}$ conversion rate for the NOMAD
neutrino detector at CERN is given.


title: Group theory factors for Feynman diagrams

abstract:
  We present algorithms for the group independent reduction of group theory
factors of Feynman diagrams. We also give formulas and values for a large
number of group invariants in which the group theory factors are expressed.
This includes formulas for various contractions of symmetric invariant tensors,
formulas and algorithms for the computation of characters and generalized
Dynkin indices and trace identities. Tables of all Dynkin indices for all
exceptional algebras are presented, as well as all trace identities to order
equal to the dual Coxeter number. Further results are available through
efficient computer algorithms (see http://norma.nikhef.nl/~t58/ and
http://norma.nikhef.nl/~t68/ ).


title: Medium effects in string-dilaton-induced neutrino oscillations

abstract:
  We consider the unconventional way to interpret the current data on solar
neutrino oscillations as derived recently by Halprin and Leung from a string
model based on the existence of the string dilaton field which remains massless
in the low-energy world. The equivalence principle violation entailed by the
existence of a massless dilaton may then produce neutrino oscillations even for
neutrinos that are degenerate in mass. Here we calculate the medium-induced
mass squared difference for solar neutrinos, which is due to their coherent
interactions with the cosmic neutrino background and with solar plasma
constituents. We show that this difference can naturally be large enough to
satisfy the known experimental limits on the Just So solution as well as on the
MSW solution of the solar neutrino problem.


title:
Effects of Parton Intrinsic Transverse Momentum on Photon Production in
  Hard-Scattering Processes

abstract:
  We calculate the photon production cross section arising from the hard
scattering of partons in nucleon-nucleon collisions by taking into account the
intrinsic parton transverse momentum distribution and the next-to-leading-order
contributions. As first pointed out by Owens, the inclusion of the intrinsic
transverse momentum distribution of partons leads to an enhancement of photon
production cross section in the region of photon transverse momenta of a few
GeV/c for nucleon-nucleon collisions at a center-of-mass energy of a few tens
of GeV. The enhancement increases as $\sqrt{s}$ decreases. Such an enhancement
is an important consideration in the region of photon momenta under
investigation in high-energy heavy-ion collisions.


title: Top quark production at threshold with O(alpha_s^2) accuracy

abstract:
  We calculate the next-to-next-to-leading order correction to the cross
section for top quark pair production in e+e- annihilation in the threshold
region, resumming all O [ (alpha_s/beta)^n (alpha_s^2, beta^2, alpha_s beta) ]
terms of perturbation series. We find that the magnitude of the NNLO correction
is comparable to the size of the NLO corrections.


title: B physics

abstract:
  A review over recent experimental progress in the physics of the fifth quark
is given.


title:
On the universality of the Milan factor for 1/Q power corrections to jet
  shapes

abstract:
  We perform the two-loop analysis of the 1/Q power corrections to jet-shape
variables. This step is necessary for producing reliable theoretical
predictions for the relative magnitudes of genuine confinement effects. We show
that the rescaling factor recently derived for the thrust case (the Milan
factor) remains the same for the class of observables which includes the
C-parameter, invariant jet masses, jet broadening and the energy-energy
correlation measure. We list the expressions which should be used for
extracting 1/Q power effects in jet shapes.
  We also envisage large non-perturbative effects, characterised by fractional
powers of Q, in certain semi-inclusive observables such as the height of the
spectrum of Drell-Yan lepton pairs with invariant mass Q and transverse
momentum Q_t=0, and back-to-back energy flows in e^+e^- and DIS.


title:
Galactic Anisotropy as Signature of ``Top-Down'' Mechanisms of
  Ultra-High Energy Cosmic Rays

abstract:
  We show that ``top-down'' mechanisms of Ultra-High Energy Cosmic Rays which
involve heavy relic particle-like objects predict Galactic anisotropy of
highest energy cosmic rays at the level of minimum $\sim 20%$. This anisotropy
is large enough to be either observed or ruled out in the next generation of
experiments.


title: Neutrino Anti-neutrino Transitions

abstract:
  We consider transitions between neutrinos and anti-neutrinos in laboratory
experiments in five scenarios, including both helicity flipping and preserving
cases.


title: Proton-proton Cross Section at sqrt(s) \sim 30 TeV

abstract:
  There are both theoretical and experimental uncertainties in using data from
cosmic-ray air showers to estimate hadronic cross sections above accelerator
energies. We outline these problems and compare the physics used to extract
\sigma_{pp}^{tot} from air shower data to the widely used parameterization of
the proton-proton cross section of Donnachie and Landshoff and other
contemporary models. We conclude that the published cosmic-ray cross section
values do not strongly constrain \sigma_{pp}^{tot} fits from lower energy
accelerator data.


title: Recent Developments In Heavy Quarkonium Physics

abstract:
  Recent developments in heavy quarknoium physics are reviewed in brief,
including (i) nonrelativistic QCD(NRQCD), (ii) the importance of color-octet
$(Q\bar{Q})$ components in the decay and the production of a physical heavy
quarkonium state, (iii) limitation of the NRQCD factorization and (iv) the
double humps in the $\pi\pi$ spectrum in the decay $\Upsilon(3S) \to \Upsilon
(1S) \pi\pi$.


title:
QCD Predictions for $g_1^p$ at Small $x$ Incorporating Double
  $ln^2(1/x)$ Resummation

abstract:
  The proton spin dependent structure function $g_1^p$ is analysed using the
unified scheme incorporating both Altarelli-Parisi evolution and the double
$ln^2(1/x)$ effects at low $x$. The latter are found to be very important in
the region of $x$ which can possibly be probed at HERA. Predictions for the
polarized gluon distribution $\Delta G(x)$ at low $x$ are also given.


title: When the Wavepacket is Unnecessary

abstract:
  We point out that many wavepacket discussions for the coherence properties of
particle beams are unnecessary since they deal with stationary sources; and
when the problem is stationary, essentially all information is in the energy
spectrum. This recognition allows a simple answer to a number of long-debated
points, usually framed in terms of "the length of the wavepacket". In
particular we discuss neutrino oscillations, and some issues in neutron
physics. The question as to whether two simple beams with the same energy
spectrum are distinguishable is answered negatively for stationary situations.
The question as to whether neutrino oscillations should be thought of as taking
place between states of the same energy or the same momentum is answered in
favor of energy for stationary situations. Consequences for proposals involving
the 7Be neutrino line of the sun, the observation of oscillations in supernova
neutrinos and wavepacket studies with neutrons are briefly discussed, as well
as the connection with the coherence notions of quantum optics.


title:
Supersymmetric $SU(2)_L\times SU(2)_R \times SU(4)_c$ and observable
  neutron-antineutron oscillation

abstract:
  We show that in a large class of supersymmetric $SU(2)_L\times SU(2)_R\times
SU(4)_c$ models with the see-saw mechanism for neutrino masses and an R-parity
conserving vacuum, there are diquark Higgs bosons with masses ($M_{qq}$) near
the weak scale even though the scale of $SU(2)_R\times SU(4)_c$ symmetry
breaking is around $10^{10}$ GeV. This happens because these masses ($M_{qq}$)
arise out of higher dimensional operators needed to stabilize the charge
conserving vacuum in the model. This feature has the interesting implication
that the $\Delta B=2$ processes such as neutron-anti-neutron oscillation can
have observable rates while at the same time yielding neutrino masses in the
range of current interest.


title: Space-like Penguin Effects in $B_{c}$ Decays

abstract:
  The space-like penguin contributions to branching ratios and CP asymmetries
in charmless decays of $B_{c}$ to two pseudoscalar mesons are studied using the
next-to-leading order low energy effective Hamiltonian and factorization
approximation. Both the gluonic penguin and the electroweak penguin diagrams
are considered. In addition the annihilation diagram contributions are also
taken in account. We find that the space-like penguin effects are significant.


title:
LSND, solar and atmospheric neutrino oscillation experiments and
  R-parity violating Supersymmetry

abstract:
  With only three flavors it is possible to account for various neutrino
oscillation experiments. The masses and mixing angles for three neutrinos can
be determined from the available experimental data on neutrino oscillation and
from the astrophysical arguments. We have shown here that such masses and
mixing angles which can explain atmospheric neutrino anomaly, LSND result and
the solar neutrino experimental data, can be reconciled with the R-parity
violating Supersymmetric Models through lepton number violating interactions.
We have estimated the order of magnitude for some lepton number violating
couplings. Our analysis indicates that the lepton number violation is likely to
be observed in near future experiments. From the data on neutrino oscillation
and the electric dipole moment of electron, under some circumstances it is
possible to obtain constraint on the complex phase of some supersymmetry
breaking parameters in R-parity violating Supersymmetric models.


title: 2HDMs predictions for $B \to X_s \gamma$ in NLO QCD

abstract:
  The decay $B \to X_s \gamma$ is studied at the Next to Leading Order in QCD
in a class of models containing at least two Higgs doublets and with only one
charged Higgs boson non-decoupled at low-energy. The two-loop matching
condition is calculated and it is found to agree with existing results. The
complete dependence of the Wilson coefficients on the matching scale is given.
The size of the Next to Leading Order corrections is extensively discussed.
Results for branching ratios, possible CP asymmetries and lower bounds on the
charged Higgs mass are presented when the convergence of the perturbative
series appears fast enough to yield reliable predictions. Regions in the
parameter space of these models where the Next to Leading Order calculation is
still not a good approximation of the final result for these observables are
singled out.


title:
An enhancement of neutral tc transitions in the model of dynamical
  breaking of the electroweak symmetry

abstract:
  The problem of possible deviations from the Standard Model is considered in
the framework of a variant of dynamical electroweak symmetry breaking. It comes
clear, that the parameters of the theory, being obtained earlier and describing
deviations from SM in Z --> \bar b b decay, are also consistent with the
existence of a nontrivial solution for vertex \bar t (Z,\gamma) c. The
occurrence of this solution leads to a significant enhancement in neutral
flavor changing transition t --> c. The intensity of this transition is
connected with the c-quark mass, that leads to estimates of probabilities of
exotic decays t --> c (Z,\gamma) (few %) and of the cross-section of a single
t-quark production in process e^+e^- --> t \bar c at LEP2 (around 0.03 pb at
\sqrt{s} = 190 GeV). The model is shown to be consistent with the totality of
the existing data; the predictions allow its unambiguous check.


title: Finite-size effects on multibody neutrino exchange

abstract:
  The effect of multibody massless neutrino exchanges between neutrons inside a
finite-size neutron star is studied. We use an effective Lagrangian, which
incorporates the effect of the neutrons on the neutrinos. Following Schwinger,
it is shown that the total interaction energy density is computed by comparing
the zero point energy of the neutrino sea with and without the star. It has
already been shown that in an infinite-size star the total energy due to
neutrino exchange vanishes exactly. The opposite claim that massless neutrino
exchange would produce a huge energy is due to an improper summation of an
infrared-divergent quantity. The same vanishing of the total energy has been
proved exactly in the case of a finite star in a one-dimensional toy model.
  Here we study the three-dimensional case. We first consider the effect of a
sharp star border, assumed to be a plane. We find that there is a non-
vanishing of the zero point energy density difference between the inside and
the outside due to the refraction index at the border and the consequent
non-penetrating waves. An analytical and numerical calculation for the case of
a spherical star with a sharp border confirms that the preceding border effect
is the dominant one. The total result is shown to be infrared-safe, thus
confirming that there is no need to assume a neutrino mass. The ultraviolet
cut-offs, which correspond in some sense to the matching of the effective
theory with the exact one, are discussed. Finally the energy due to long
distance neutrino exchange is of the order of $10^{-8} -- 10^{-13} GeV per
neutron$, i.e. negligible with respect to the neutron mass density.


title: B->pi and B->K Transitions from QCD Sum Rules on the Light-Cone

abstract:
  I calculate the form factors describing semileptonic and penguin-induced
decays of B mesons into light pseudoscalar mesons. The form factors are
calculated from QCD sum rules on the light-cone including contributions up to
twist 4, radiative corrections to the leading twist contribution and
SU(3)-breaking effects. The theoretical uncertainty is estimated to be \sim
15%. The heavy-quark-limit relations between semileptonic and penguin form
factors are found to be valid in the full accessible range of momentum
transfer.


title: Core Phase Transitions for Embedded Topological Defects

abstract:
  Vortices in superfluid 3He-B have been observed to undergo a core transition.
We discuss the analog phenomenon in relativistic field theories which admit
embedded global domain walls, vortices and monopoles with a core phase
structure. They are present in scalar field theories with approximate global
symmetries which are broken both spontaneously and in parts explicitly. For a
particular range of parameters their symmetric core exhibits an instability and
decays into the nonsymmetric phase.


title:
Study of the reaction pi- p --> pi- pi+ n on the polarized proton target
  at 1.78 GeV/c. Experiment and amplitude analysis

abstract:
  We present the results of the experimental study of the reaction of dipion
production by the beam of the negative pions with momentum 1.78 GeV/c on the
polarized proton and liquid hydrogen targets. The experiment covers the region
of dipion masses near the mass of rho-meson and small momenta transferred
|t|<0.2(GeV/c)^2. The whole set of spin density matrix elements was
reconstructed and model-independent and model-dependent amplitude analyses of
the reaction were performed. The experiment allows to exclude the ambiguity of
the amplitude analysis existing at high energies. The results contain evidences
in favour of existing of narrow sigma(750). The data also allows to estimate
intercept of a_1-meson Regge trajectory.
  The experiment was performed at the ITEP proton synchrotron, Moscow.


title: Thermally induced photon splitting

abstract:
  We calculate thermal corrections to the non-linear QED effective action for
low-energy photon interactions in a background electromagnetic field. The
high-temperature expansion shows that at $T \gg m$ the vacuum contribution is
exactly cancelled to all orders in the external field except for a non-trivial
two-point function contribution. The high-temperature expansion derived reveals
a remarkable cancellation of infrared sensitive contributions. As a result
photon-splitting in the presence of a magnetic field is suppressed in the
presence of an electron-positron QED-plasma at very high temperatures. In a
cold and dense plasma a similar suppression takes place. At the same time
Compton scattering dominates for weak fields and the suppression is rarely
important in physical situations.


title: Anomalies at high temperature

abstract:
  The anomaly equation can be derived from the ultraviolet properties of
quantum field theory and should, therefore, not depend on infrared properties,
such as the presence of a thermal heat bath. There is also an infrared
explanation of anomalies which is related to fermionic zero modes. I show how
the anomaly equation can be satisfied in a high temperature plasma in spite of
the fact that all propagating fermionic excitations have a thermal mass.


title: String Phenomenology

abstract:
  Following Dyson's analogy between the quantum field theory and the
19th-century chemistry-both explain how but not why-one could also establish an
analogy between atomic physics and string theory. Atomic physics was needed to
answer the question why in chemistry, string theory is trying to answer the
question why in the standard model. This attempt is very briefly reviewed in
this talk. After discussing the phenomenological aspects of string theory, the
study of soft terms is emphasized as a possible connection between theory and
experiment. Special attention is paid to the issues of flavor changing neutral
currents, loop effects, charge and color breaking minima, and M-theory versus
weakly coupled string theory.


title: Beyond The Standard Model: An Answer and Twenty Questions

abstract:
  These are the essence of two lectures given at the Ettore Majorana Summer
School, 1997, and the discussion sections which followed them. The title
indicates their content: some reasoned expectations for physics beyond the
Standard Model, and an annotated list of major open questions.