title:
Pion-nucleon scattering in an effective chiral field theory with
  explicit spin-3/2 fields

abstract:
  We analyze elastic-pion nucleon scattering to third order in the so-called
small scale expansion. It is based on an effective Lagrangian including pions,
nucleons and deltas as active degrees of freedom and counting external momenta,
the pion mass and the nucleon-delta mass splitting as small parameters. The
fermion fields are considered as very heavy. We present results for phase
shifts, threshold parameters and the sigma term. We discuss the convergence of
the approach. A detailed comparison with results obtained in heavy baryon
chiral perturbation theory to third and fourth order is also given.


title: Parton Distributions Working Group

abstract:
  The main focus of this working group was to investigate the different issues
associated with the development of quantitative tools to estimate parton
distribution functions uncertainties. In the conclusion, we introduce a
"Manifesto" that describes an optimal method for reporting data.


title: Theoretical constraints on interaction amplitudes of light mesons

abstract:
  We impose unitarity constraints on the S-wave isoscalar pion-pion amplitudes
extracted from the analysis of the pi- p ---> pi+ pi- n data which have been
measured by the CERN-Cracow-Munich collaboration on a transversely polarized
target at 17.2 GeV/c pi- momentum. Two "steep" solutions contain a narrow
S-wave f0(750) resonance under the rho(770) and exhibit a considerable
inelasticity eta which is in disagreement with the four pion production data
below the KKbar threshold. We impose eta= 1 for all data points and examine
four sets of solutions for the S-wave isoscalar phase-shifts. The "down-flat"
and "up-flat" solutions easily pass the eta=1 constraint but the remaining
"down-steep" and "up-steep" are eliminated. We conclude that the 17.2 GeV data
cannot be described by a relatively narrow f0(750).


title: When is it possible to use perturbation technique in field theory ?

abstract:
  The vector pion form factor is used as an example to analyze this question.
Given the experimental radius of the pion, the crucial question is whether
perturbative methods could be used for the effective chiral lagrangian to
calculate the pion form factor. Our analysis shows that the pion rms radius is
far too large (or the related rho resonance mass is too low) for the
perturbation theory to be valid.


title:
Peculiarities in multichannel interaction amplitudes for meson-meson
  scattering and scalar meson spectroscopy

abstract:
  Interactions in coupled channels pipi, KKbar and an effective 2pi2pi in
scalar-isoscalar wave have been analysed. Influence of interchannel couplings
on analytical structure of multichannel interaction amplitudes has been
studied. Interplay of S-matrix zeroes and poles and their relation with
parameters of scalar resonances has been investigated.


title: Radiative corrections to Zb{\bar b} production

abstract:
  We report on QCD radiative corrections to the process, p\bar{p} to Zb\bar{b}
in the approximation in which the b-quark is considered massless. The
implementation of this process in the general purpose Monte Carlo program MCFM
is discussed in some detail. These results are used to investigate backgrounds
to Higgs boson production in the ZH channel. We investigate the Higgs mass
range (100 GeV < m_H < 130 GeV) for the Tevatron running at sqrt{s}=2 TeV.


title: Effective Field Theory at Moderate Nuclear Density

abstract:
  Effective field theory of the in-medium nucleon-nucleon interaction is
considered. The effective range parameters are found to be of a natural scale.
The low density limit is discussed both in perturbative and nonperturbative
situations. In the nonperturbative case the attractive character of the
nucleon-nucleon interactions in the $^{1}S_0$ channel leads to the nuclear
superfluidity which is analyzed in the framework of the renormalization group.
The numerical values of the corresponding energy gap are in agreement with
results obtained by more more traditional many-body techniques. The S-wave part
of potential energy per particle is calculated for different values of nuclear
density. The role of pion and many-body effects is discussed. Problems and
challenges in constructing the chiral theory of nuclear matter are outlined.


title:
Chiral Extrapolation, Renormalization, and the Viability of the Quark
  Model

abstract:
  The relationship of the quark model to the known chiral properties of QCD is
a longstanding problem in the interpretation of low energy QCD. In particular,
how can the pion be viewed as both a collective Goldstone boson quasiparticle
and as a valence quark antiquark bound state where universal hyperfine
interactions govern spin splittings in the same way as in the heavy quark
systems. We address this issue in a simplified model which; however, reproduces
all features of QCD relevant to this problem. A comparison of the many-body
solution to our model and the constituent quark model demonstrates that the
quark model is sufficiently flexible to describe meson hyperfine splitting
provided proper renormalization conditions and correct degrees of freedom are
employed consistently.


title:
Electroweak radiative corrections to e+e- --> WW --> 4fermions in
  double-pole approximation -- the RACOONWW approach

abstract:
  We calculate the complete O(alpha) electroweak radiative corrections to e+e-
--> WW --> 4f in the electroweak Standard Model in the double-pole
approximation. We give analytical results for the non-factorizable virtual
corrections and express the factorizable virtual corrections in terms of the
known corrections to on-shell W-pair production and W decay. The calculation of
the bremsstrahlung corrections, i.e. the processes e+e- --> 4f+gamma in lowest
order, is based on the full matrix elements. The matching of soft and collinear
singularities between virtual and real corrections is done alternatively in two
different ways, namely by using a subtraction method and by applying
phase-space slicing. The O(alpha) corrections as well as higher-order
initial-state photon radiation are implemented in the Monte Carlo generator
RACOONWW. Numerical results of this program are presented for the
W-pair-production cross section, angular and W-invariant-mass distributions at
LEP2. We also discuss the intrinsic theoretical uncertainty of our approach.


title: SUSY Search in TeV Scale Polarized Photon-Proton Collisions

abstract:
  Production of supersymmetric particles in TeV scale polarized photon-proton
collisions is discussed. Polarizations of both photon and proton beams are
considered. Associated productions of squark-chargino and squark-gluino, and
production of squark pairs have been examined. Although the cross sections for
different initial beam polarizations do not differ much, the polarization
asymmetry is sensitive to the sparticle mass. We conclude that the capacity of
future linac-ring type TeV scale photon-proton colliders is quite promising in
the search for SUSY particles.


title: Radiative corrections to e+e- --> WW --> 4f with RACOONWW

abstract:
  RACOONWW is the first Monte Carlo generator for e+e- --> WW --> 4f(+gamma)
that includes the electroweak O(alpha) radiative corrections in the double-pole
approximation completely. Some numerical results for LEP2 energies are
discussed, and the predictions for the total W-pair cross section are
confronted with LEP2 data.


title:
Dynamical Higher-Twist and High x Phenomena: A Window to Quark-Quark
  Correlations in QCD

abstract:
  Measurements of the power-law corrections to Bjorken scaling and the behavior
of structure functions in the highly stressed $x_{bj} \to 1$ regime of
electroproduction can lead to new information on the quark-quark correlations
controlling the nucleon wavefunction at far-off-shell kinematics.
Electroproduction on nuclei at $ A > x_{bj} > 1$ is sensitive to hidden-color
components of the nuclear wavefunction. A distinctive dynamical higher-twist
${\cal O}(1/Q^2)$ correction, which is dynamically enhanced at high $x_{bj}$,
can arise from the interference of amplitudes where the lepton scatters from
two different valence quarks of the target. Measurements of the
parity-violating left-right asymmetry $A_{LR}$ in elastic and inelastic
polarized electron scattering at large $x_{bj}$ can confirm the structure of
the quark-quark correlations and other QCD physics at the amplitude level.


title: P Pbar to T Tbar H: A Discovery mode for the Higgs boson at the Tevatron

abstract:
  The production of a Standard Model Higgs boson in association with a top
quark pair at the upcoming high luminosity run (15 inverse fb integrated
luminosity) of the Fermilab Tevatron (root s = 2.0 TeV) is revisited. For Higgs
masses below 140 GeV we demonstrate that the production cross section times
branching ratio for H->B Bbar decays yields a significant number of events and
that this mode is competitive with and complementary to the searches using P
Pbar -> WH, ZH associated production. For higher mass Higgs bosons the H -> W+
W- decays are more difficult but have the potential to provide a few
spectacular events.


title: Small Neutrino Masses from Supersymmetry Breaking

abstract:
  An alternative to the conventional see-saw mechanism is proposed to explain
the origin of small neutrino masses in supersymmetric theories. The masses and
couplings of the right-handed neutrino field are suppressed by supersymmetry
breaking, in a way similar to the suppression of the Higgs doublet mass, $\mu$.
New mechanisms for light Majorana, Dirac and sterile neutrinos arise, depending
on the degree of suppression. Superpartner phenomenology is greatly altered by
the presence of weak scale right-handed sneutrinos, which may have a coupling
to a Higgs boson and a left-handed sneutrino. The sneutrino spectrum and
couplings are quite unlike the conventional case - the lightest sneutrino can
be the dark matter and predictions are given for event rates at upcoming halo
dark matter direct detection experiments. Higgs decays and search strategies
are changed. Copious Higgs production at hadron colliders can result from
cascade decays of squarks and gluinos.


title:
New Production Mechanism of Neutral Higgs Bosons with Right scalar tau
  neutrino as the LSP

abstract:
  Motived by the neutrino oscillation data, we consider the lightest tau
sneutrino $\tilde \nu_{\tau_1}$ (which is mostly the right tau sneutrino) to be
the lightest supersymmetric particle (LSP) in the framework of the minimal
supersymmetric Standard Model. Both the standard and the non-standard trilinear
scalar coupling terms are included for the right tau sneutrino interactions.
The decay branching ratio of $\tilde \nu_{\tau_2} \to \tilde \nu_{\tau_1}+ h^0$
can become so large that the production rate of the lightest neutral Higgs
boson ($h^0$) can be largely enhanced at electron or hadron colliders, either
from the direct production of $\tilde \nu_{\tau_2}$ or from the decay of
charginos, neutralinos, sleptons, and the cascade decay of squarks and gluinos,
etc. Furthermore, because of the small LSP annihilation rate, $\tilde
\nu_{\tau_1}$ can be a good candidate for cold dark matter.


title: Reduction and evaluation of two-loop graphs with arbitrary masses

abstract:
  We describe a general analytic-numerical reduction scheme for evaluating any
2-loop diagrams with general kinematics and general renormalizable
interactions, whereby ten special functions form a complete set after tensor
reduction. We discuss the symmetrical analytic structure of these special
functions in their integral representation, which allows for optimized
numerical integration. The process Z -> bb is used for illustration, for which
we evaluate all the 3-point, non-factorizable g^2*alpha_s mixed electroweak-QCD
graphs, which depend on the top quark mass. The isolation of infrared
singularities is detailed, and numerical results are given for all two-loop
three-point graphs involved in this process.


title: Bound on $\cos\alpha$ from exclusive weak radiative B decays

abstract:
  We present a bound on the weak phase $\alpha$ from isospin-breaking effects
in weak radiative decays, which requires the CP-averaged branching ratios for
the weak radiative decays $B^\pm\to \rho^\pm \gamma$, $B^0\to \rho^0/\omega
\gamma$, $B\to K^* \gamma$ and the photon energy spectrum in $B\to\gamma
\ell\nu_\ell$. We carefully identify all sources of isospin breaking, which
could possibly mask information about the CKM parameters. They are introduced
by diagrams with photon bremsstrahlung off the spectator quark and diagrams
with annihilation penguin topologies. The former can be eliminated by combining
$B\to\rho\gamma$ and $B\to K^{*}\gamma$ data, whereas the latter effects are
OZI-suppressed and can be controlled by measuring also the modes $B_s\to
\rho(\omega)\gamma$. The resulting bound excludes values of $\alpha$ around
$90^\circ$, provided that the combined ratio ${\cal B}(B^\pm \to
\rho^\pm\gamma)/{\cal B}(B^0 \to \rho^0/\omega\gamma) \times {\cal B}(B^0 \to
K^{*0}\gamma)/{\cal B}(B^\pm \to K^{*\pm}\gamma)$ is found to be different from
1.


title:
Interference pattern of the Coulomb and the strong Van der Waals forces
  in p-p scattering

abstract:
  In order to confirm the strong Van der Waals force in the nucleon-nucleon
interaction, it is proposed to measure precisely the angular distribution of
the cross section of the low energy ($T_{lab}=20 \sim 30MeV.$) proton-proton
scattering. By using the spectrum of the long range interaction obtained from
the analysis of the phase shift data of the S-wave of the p-p scattering, a
characteristic interference pattern, which arises from the repulsive Coulomb
and the attractive strong Van der Waals forces, is predicted. The pattern has a
dip at $theta_{c.m.}=14^{\circ}$ with the depth around one per cent.


title:
Momentum-dependent contributions to the gravitational coupling of
  neutrinos in a medium

abstract:
  When neutrinos travel through a normal matter medium, the electron neutrinos
couple differently to gravity compared to the other neutrinos, due to the
presence of electrons in the medium and the absence of the other charged
leptons. We calculate the momentum-dependent part of the matter-induced
gravitational couplings of the neutrinos under such conditions, which arise at
order $g^2/M^4_W$, and determine their contribution to the neutrino dispersion
relation in the presence of a gravitational potential $\phi^{\mathrm{ext}}$.
These new contributions vanish for the muon and tau neutrinos. For electron
neutrinos with momentum $K$, they are of the order of the usual Wolfenstein
term times the factor $(K^2/M^2_W)\phi^{\mathrm{ext}}$, for high energy
neutrinos. In environments where the gravitational potential is substantial,
such as those in the vicinity of Active Galactic Nuclei, they could be the
dominant term in the neutrino dispersion relation. They must also be taken into
account in the analysis of possible violations of the Equivalence Principle in
the neutrino sector, in experimental settings involving high energy neutrinos
traveling through a matter background.


title:
A note on the RG flow in (N=1, D=4) Supergravity and applications to Z_3
  orbifold/orientifold compactification

abstract:
  We apply the standard approach of RG flow for the gauge couplings in N=1 D=4
Supergravity to show how to match its results with the heterotic $Z_3$ orbifold
and Type IIB ${Z_3}$ orientifold-based models. Using only supergravity, anomaly
cancellation and the requirement of unification we determine the part of the
K\"ahler potential of the model invariant under the symmetries of the model.
For heterotic orbifolds/type IIB orientifolds, this shows that the lowest order
K\"ahler term of the dilaton has the structure $-\ln(S+{\bar S})$ in agreement
with string calculations. The structure of the holomorphic coupling is also
found from arguments of unification and anomaly cancellation under the
conjectured $SL(2,Z)_{T_i}$ symmetries of the models. A consequence of the
latter is that in the case of the $Z_3$ orientifold the holomorphic coupling
necessarily contains a part with coefficient proportional to the one loop beta
function, in agreement with string calculations which do not however assume
this symmetry. This gives circumstantial evidence for the existence of this
symmetry at string level in $Z_3$ orientifold. Finally, we comment on the
values of the unification scale and examine the possibility of mirage
unification in which the effective unification scale may be situated far above
the string scale.


title:
Four neutrino oscillation analysis of the Superkamiokande atmospheric
  neutrino data

abstract:
  Superkamiokande atmospheric neutrino data (contained and upward going through
$\mu$ events) for 990 days are analyzed in the framework of four neutrinos
(three active and one sterile neutrinos) without imposing constraints of Big
Bang Nucleosynthesis. It is shown that the wide range of the oscillation
parameters is allowed at 90% confidence level ($0.1\lesssim
|U_{s1}|^2+|U_{s2}|^2\le 1$), where the best fit point has some contribution of
$\nu_\mu\leftrightarrow\nu_s$ and contribution of $\Delta m^2_{\rm\scriptsize
LSND}$. The case of pure $\nu_\mu\leftrightarrow\nu_s$ oscillation is excluded
at 99.7%CL (3.0$\sigma$) which is consistent with the recent analysis by the
Superkamiokande group. Combining this result with the analysis by Giunti,
Gonzarez-Garcia and Pe\~na-Garay, it is found that the Large Mixing Angle and
Vacuum Oscillation solutions of the solar neutrino problem are also allowed.


title: On the range of validity of the parton model

abstract:
  Based on the world DIS data we extract $F_2^p - F_2^n$ as a function of
Bjorken $x$ and photon virtuality $Q^2$. The standard PDFs fail to describe the
experimental data below $Q^2 <$ 7 GeV$^2$. The trend of the data is
approximately explained by our recent model.


title: DVCS amplitude in the parton model

abstract:
  We compute amplitude of deeply virtual Compton scattering in the parton
model. We found that the amplitude up to the accuracy O(1/Q) depends on new
skewed parton distributions (SPD's). These additional contributions make the
DVCS amplitude explicitly transverse.


title:
Hadronic Invariant Mass Spectrum in B -> X_u l nu Decay with Lepton
  Energy Cut

abstract:
  We discuss the implications of charged lepton energy cut to the hadronic
invariant mass spectrum in charmless semileptonic B decays. Charged-lepton
energy cut is inevitable in order to remove secondary leptonic events such as b
-> c, tau -> l, and to identify the chaged leptons at detectors experimentally.
We consider three possible lepton energy cuts, E_l^{cuts} = 0.6,1.5,2.3 GeV,
and found that with the most probable cuts E_l^{cut} = 1.5 GeV and M_X^{max} =
1.5~(1.86) GeV, 45 ~ 60 % ~(58 ~ 67 %) of decay events survive. Therefore, B ->
X_u l nu decay events can be efficiently distinguished from B -> X_c l nu decay
events. We also discuss the possible model dependence on the results.


title: A New Property of the Quark-Antiquark Potential in a Quark-Gluon Plasma

abstract:
  I consider the behavior of the quark-antiquark potential, called the Cornell
Potential, in a quark-gluon plasma. Since mesons are no longer bound in the
quark-gluon plasma, there might be a relationship between the string tension of
the quark-antiquark potential, the mass of the quark, and the coupling
constant.


title: On the search for 50 GeV neutrinos

abstract:
  Using the computer code CompHEP we estimate the number of events and the
background, at LEP II and TESLA, for the reaction $e^+ e^- \to N\bar{N}\gamma$,
where $N$ is a hypothetical Dirac neutrino with mass of the order of 50 GeV.


title: Baryon Number Flow in High-Energy Collisions

abstract:
  It is not obvious which partons in the proton carry its baryon number (BN).
We present arguments that BN is associated with a specific topology of gluonic
fields, rather than with the valence quarks. The BN distribution is easily
confused with the difference between the quark and antiquark distributions. We
argue, however, that they have quite different x-dependences. The distribution
of BN asymmetry distribution is nearly constant at small x while q(x)-\bar q(x)
\propto \sqrt{x}. This constancy of BN produces energy independence of the \bar
pp annihilation cross section at high energies. Recent measurement of the
baryon asymmetry at small x at HERA confirms this expectation. The BN asymmetry
at mid-rapidities in heavy ion collisions is substantially enhanced by multiple
interactions, as has been observed in recent experiments at the SPS. The same
gluonic mechanism of BN stopping increases the production rate for cascade
hyperons in a good accord with data. We expect nearly the same as at SPS amount
of BN stopped in higher energy collisions at RHIC and LHC, which is, however,
spread ove larger rapidity intervals.


title:
Broadening of Transverse Momentum of Partons Propagating through a
  Medium

abstract:
  Broadening of the transverse momentum of a parton propagating through a
medium is treated using the color dipole formalism, which has the advantage of
being a well developed phenomenology in deep-inelastic scattering and soft
processes. Within this approach, nuclear broadening should be treated as color
filtering, i.e. absorption of large-size dipoles leading to diminishing
(enlarged) transverse separation (momentum). We also present a more intuitive
derivation based on the classic scattering theory of Moli\`ere. This derivation
helps to understand the origin of the dipole cross section, part of which comes
from attenuation of the quark, while another part is due to multiple
interactions of the quark. It also demonstrates that the lowest-order
rescattering term provides an A-dependence very different from the generally
accepted A^{1/3} behavior. The effect of broadening increases with energy, and
we evaluate it using different phenomenological models for the unintegrated
gluon density. Although the process is dominated by soft interactions, the
phenomenology we use is tested using hadronic cross section data.


title:
Search for solar Kaluza-Klein axions in theories of low-scale quantum
  gravity

abstract:
  We explore the physics potential of a terrestrial detector for observing
axionic Kaluza-Klein excitations coming from the Sun within the context of
higher-dimensional theories of low-scale quantum gravity. In these theories,
the heavier Kaluza-Klein axions are relatively short-lived and may be detected
by a coincidental triggering of their two-photon decay mode. Because of the
expected high multiplicity of the solar axionic excitations, we find
experimental sensitivity to a fundamental Peccei-Quinn axion mass up to
$10^{-2}$ eV (corresponding to an effective axion-photon coupling $g_{a\gamma
\gamma} \approx 2.\times 10^{-12}$ GeV$^{-1}$) in theories with 2 extra
dimensions and a fundamental quantum-gravity scale $M_{\rm F}$ of order 100
TeV, and up to $3.\times 10^{-3}$ eV (corresponding to $g_{a\gamma \gamma}
\approx 6.\times 10^{-13}$ GeV$^{-1}$) in theories with 3 extra dimensions and
$M_{\rm F}=1$ TeV. For comparison, based on recent data obtained from lowest
level underground experiments, we derive the experimental limits: $g_{a \gamma
\gamma} \stackrel{<}{{}_\sim} 2.5\times 10^{-11}$ GeV$^{-1}$ and $g_{a \gamma
\gamma} \stackrel{<}{{}_\sim} 1.2\times 10^{-11}$ GeV$^{-1}$ in the
aforementioned theories with 2 and 3 large compact dimensions, respectively.


title: Ultrahigh Energy Neutrinos and the Highest Energy Cosmic Rays

abstract:
  It has been suggested that the characteristic energy of string models may be
considerably lower than the observed Planck mass. In such schemes, the
unification of interactions takes place around the string scale, perhaps as low
as a few tens of TeV. Consequently, at energies above the string scale,
neutrinos acquire interactions comparable in strength to strong interactions.
While they can propagate through the CMBR essentially uninhibited, in
interactions with nuclei in the atmosphere they induce air showers comparable
to proton induced ones. We conjecture that air showers above the
Greisen-Zatsepin-Kuzmin (GZK) cutoff in the cosmic radiation are induced by
such neutrinos. A Monte Carlo simulation shows that neutrino induced
"anomalous" showers are virtually indistinguishable from proton induced ones on
an event-by event basis. However, given sufficient statistics in detectors
(HiRes, OWL, Auger etc.), the post-GZK showers are expected to exhibit
characteristics in the fluctuation pattern allowing a distinction between
proton and neutrino induced showers.


title:
Enhanced electric dipole moment of the muon in the presence of large
  neutrino mixing

abstract:
  The electric dipole moment of the muon (d_mu) is evaluated in supersymmetric
models with nonzero neutrino masses and large neutrino mixing arising from the
seesaw mechanism. It is found that if the seesaw mechanism is embedded in the
framework of a left-right symmetric gauge structure, the interactions
responsible for the right-handed neutrino Majorana masses lead to an
enhancement in d_mu. We find d_mu as large as 5. 10^{-23} ecm with a correlated
value of (g-2) = 13. 10^{-10}, even for low values of tan beta. This should
provide a strong motivation for improving the edm of the muon to the level of
10^{-24} ecm as has recently been proposed.


title: KN interaction in the quark-gluon exchange framework

abstract:
  The general meson-baryon potential obtained in the context of the Fock-Tani
formalism is applied in the $K^{+}N$ system. A simple spin-dependent
interaction on quark level is used in order to compare with known results. The
short range nature of the equivalent local potential is shown.


title: Left-Right Symmetric Heterotic-String Derived Models

abstract:
  Recently it was demonstrated that free fermionic heterotic-strings can
produce models with solely the Minimal Supersymmetric Standard Model states in
the low energy spectrum. This unprecedented result provides further strong
evidence for the possibility that the true string vacuum shares some of the
properties of the free fermionic models. Past free fermionic models have
focused on several possible unbroken observable SO(10) subgroups at the string
scale, which include the flipped SU(5) (FSU5), the Pati-Salam (PS) string
models, and the string Standard-like Models (SLM). We extend this study to
include the case in which the SO(10) symmetry is broken to the Left-Right
Symmetric (LRS) gauge group, SO(10) -> SU(3)_C X U(1)_{B-L} X SU(2)_L X
SU(2)_R. We present several models of this type and discuss their
phenomenological features. The most striking new outcome of the LRS string
models, in contrast to the case of the FSU5, the PS, and the SLM string models,
is that they can produce effective field theories that are free of Abelian
anomalies. We discuss the distinction between the two types of free fermionic
models which result in the presence, or absence, of an anomalous U(1). As a
counter example we also present a LRS model that does contain an anomalous
U(1). Additionally, we discuss how in string models the Standard Model spectrum
may arise from the three $\mbf 16$ representations of SO(10), while the
weak-hypercharge does not have the canonical SO(10) embedding.


title: Lepton Number And Neutrino Masses

abstract:
  I briefly review the arguments which in the 1970's convinced many theoretical
physicists to anticipate lepton number violation, and to guess a range of
neutrino masses.


title: Large N Quantum Time Evolution Beyond Leading Order

abstract:
  For quantum theories with a classical limit (which includes the large N
limits of typical field theories), we derive a hierarchy of evolution equations
for equal time correlators which systematically incorporate corrections to the
limiting classical evolution. Explicit expressions are given for
next-to-leading order, and next-to-next-to-leading order time evolution. The
large N limit of N-component vector models, and the usual semiclassical limit
of point particle quantum mechanics are used as concrete examples. Our
formulation directly exploits the appropriate group structure which underlies
the construction of suitable coherent states and generates the classical phase
space. We discuss the growth of truncation error with time, and argue that
truncations of the large-N evolution equations are generically expected to be
useful only for times short compared to a ``decoherence'' time which scales
like N^{1/2}.


title:
How do Neutrinos Propagate ? - Wave-Packet Treatment of Neutrino
  Oscillation

abstract:
  The wave-packet treatment of neutrino oscillation developed previously is
extended to the case in which momentum distribution functions are taken to be a
Gaussian form with both central values and dispersions depending on the mass
eigenstates of the neutrinos. It is shown among other things that the velocity
of the neutrino wave packets does not in general agree with what one would
expect classically and that relativistic neutrinos emitted from pions
nevertheless do follow, to a good approximation, the classical trajectory.


title: Leptoquark Searches at Future Colliders

abstract:
  Leptoquark searches are considered for future experiments at HERA, Tevatron,
LHC, TESLA and THERA. Expected exclusion limits from direct leptoquark searches
(leptoquark pair production and single leptoquark production) are compared with
indirect limits expected from the contact interaction analysis. Strongest
limits on the leptoquark masses and couplings are expected from high luminosity
LHC data. If the leptoquark signal suggested by the existing data is detected
at LHC, with mass below 1 TeV, TESLA will be an ideal place to study leptoquark
properties, provided that the leptoquark Yukawa coupling is not too small.


title: Time Evolution of Decay Spectrum in K^0, K^0 bar -> pi^+ pi^- e^+ e^-

abstract:
  We consider the decay K^0 (K^0 bar) -> pi^+ pi^- e^+ e^- of a neutral K meson
prepared in a state of strangeness +1 (-1). The time evolution of the state
produces remarkable time-dependent effects in the angular distribution of the
pi^+ pi^- e^+ e^- system. These effects are correlated with the time-dependence
of the photon polarization in the radiative decay K^0 (K^0 bar) -> pi^+ pi^-
gamma. We study, in particular, the CP-odd, T-odd term in the distribution d
Gamma / d phi of the angle between the pi^+ pi^- and the e^+ e^- planes. We
also give the spectrum in the case that the decaying meson is an incoherent
mixture of K^0 and K^0 bar, and discuss the case of K_S regeneration in a K_L
beam.


title:
Impact of Hadronic Axions on Black Hole Accretion Discs and Neutron
  Stars

abstract:
  We re-examine the possibility of an astrophysically allowed KSVZ-type axion
that has a strongly suppressed coupling to photons. We then investigate the
impact of such ''hadronic axions'' on two classes of astrophysical objects:
black hole accretion disc (BHAD) based gamma-ray bursts and isolated
neutron-stars. Although our results are sensitive to details of the underlying
models, we show that hadronic axions could in principle play an important role
in the evolution of gamma-ray bursts and in the cooling behaviour of neutron
stars.


title: Implications of a Rotating Mass Matrix

abstract:
  The fermion mass matrix, in addition to having eigenvalues (masses) which
run, also changes its orientation (rotates) with changing energy scales. This
means that its eigenstates at one scale will no longer be eigenstates at
another scale, leading to effects where fermions of different flavours can
``transmute'' into one another. In this paper, the implications of a rotating
mass matrix are analysed and possible transmuation effects are investigated
both in the Standard Model (SM) and in the so-called Dualized Standard Model
(DSM) that we advocate, arriving at the conclusion that some transmutational
decays such as $\psi \longrightarrow \mu \tau$, $\Upsilon \longrightarrow \mu
\tau$ or $\pi^0 \longrightarrow e \mu$ may be within experimental range, if not
immediately, then in the near future.


title:
Spectrum of neutrino masses and their nature in the light of present and
  future experiments

abstract:
  The present experimental data on neutrino oscillations, neutrinoless double
beta decay and tritium beta decay are collected together and possible mass
ranges for Dirac and Majorana neutrinos are found. Four future experimental
situations are investigated: both decay experiments give only upper bounds, one
of them gives a positive result ($|< m_\nu > | \neq 0$ or $m_\beta \neq 0$), or
finally both effective neutrino masses are different from zero ($|< m_\nu > |
\neq 0$ and $m_\beta \neq 0$). Each scenario gives new information on neutrino
masses and nature but only the last has a chance to resolve the problem and
give some additional information on CP violation in the lepton sector.


title: Light Sterile Neutrinos from Large Extra Dimensions

abstract:
  An experimentally verifiable Higgs-triplet model of neutrino masses from
large extra dimensions was recently proposed. We extend it to accomodate a
light sterile neutrino which also mixes with the three active neutrinos. A
previously proposed phenomenological model of four neutrinos (\underline {the
only viable such model now left}, in view of the latest atmospheric and solar
neutrino-oscillation data) is specifically realized.


title: Constraining the free parameter of the high parton density effects

abstract:
  The high density parton effects are strongly dependent of the spatial gluon
distribution within the proton, with radius $R$, which cannot be derived from
perturbative QCD. In this paper we assume that the unitarity corrections are
present in the HERA kinematical region and constrain the value of $R$ using the
data for the proton structure function and its slope. We obtain that the gluons
are not distributed uniformly in the whole proton disc, but behave as
concentrated in smaller regions.


title: Testing for New Couplings in Top Quark Decay

abstract:
  Tests of the Lorentz structure of t --> W b decay will be carried out at the
Tevatron, and later at the LHC and at a NLC. To quantitatively assay future
measurements of competing observables, we consider the (V-A) coupling values of
the helicity decay parameters versus "(V-A) + Single Additional Lorentz
Structures". Three phase-type ambiguities exist, but measurement of the sign of
the large interference between the W boson longitudinal/transverse amplitudes
could exclude the two due dynamically to additional (S+P) and (f_M + f_E)
couplings. Sizable T-violation signatures can occur for low-effective mass
scales, < 320 GeV, but in most cases can be more simply excluded by 10%
precision measurement of the probabilities P(W_L) and P(b_L). Signatures for
the presence of T-violation associated with the dynamical phase-type
ambiguities, CP-violation signatures, and Lambda_b polarimetry are also
discussed.


title:
Vacuum and MSW interpretations of solar neutrino data with the LNW mass
  matrix

abstract:
  The Lehmann-Newton-Wu mass matrix, which was recently applied to neutrinos,
is further investigated. The analytic results presented earlier are confirmed
numerically for the solar density profile of the Standard Solar Model. The
combined analysis of atmospheric and solar neutrino data favors the MSW
solution over the vacuum-oscillation solution. The total rates from the solar
neutrino detectors and spectrum distortion reported by the Super-Kamiokande
collaboration for solar neutrinos favors one heavy (m3\sim 0.05 eV) and two
light (m1, m2\lsim 0.003 eV) neutrinos.


title: Stable Q-balls from extra dimensions

abstract:
  Given a bulk scalar field with sufficient self-interactions in a higher
dimensional spacetime, it is shown that the continuous symmetries in four
dimensions, induced by the topological structure of the compact manifold,
naturally lead to formation of stable nontopological solitons of Q-ball type.
The mass per unit charge inside the soliton is bounded by the size of the extra
dimensions, and it is thus stable with respect to decaying into excited levels
of all bulk fields, irrespective of their bulk masses. A familiar example is
the Standard Model in the bulk, where the Kaluza-Klein levels of the Higgs
boson form a stable Q-ball. These stable solitons are natural candidates for
the dark matter in the Universe.


title: Computation of $\bar{\Lambda}$ and $\lambda_1$ with Lattice QCD

abstract:
  We pursue a new method, based on lattice QCD, for determining the quantities
$\bar{\Lambda}$, $\lambda_1$, and $\lambda_2$ of heavy-quark effective theory.
We combine Monte Carlo data for the meson mass spectrum with perturbative
calculations of the short-distance behavior, to extract $\bar{\Lambda}$ and
$\lambda_1$ from a formula from HQET. Taking into account uncertainties from
fitting the mass dependence and from taking the continuum limit, we find
$\bar{\Lambda} = 0.68{+0.02}_{-0.12} \text{GeV}$ and $\lambda_1 = -(0.45 \pm
0.12) \text{GeV}^2$ in the quenched approximation.


title: Precision Studies of Duality in the 't Hooft Model

abstract:
  We address numerical aspects of local quark-hadron duality using the example
of the exactly solvable 't Hooft model, two-dimensional QCD with N_c -->
infinity. The primary focus of these studies is total semileptonic decay widths
relevant for extracting |V_{cb}| and |V_{ub}|. We compare the exact
channel-by-channel sum of exclusive modes to the corresponding rates obtained
in the standard 1/m_Q expansion arising from the Operator Product Expansion. An
impressive agreement sets in unexpectedly early, immediately after the
threshold for the first hadronic excitation in the final state. Yet even at
higher energy release it is possible to discern the seeds of duality-violating
oscillations. We find the ``Small Velocity'' sum rules to be exceptionally well
saturated already by the first excited state. We also obtain a convincing
degree of duality in the differential distributions and in an analogue of
R_{e^+e^-}(s). Finally, we discuss possible lessons for semileptonic decays of
actual heavy quarks in QCD.


title: Relic Neutrino Asymmetries

abstract:
  I review the topic of relic neutrino asymmetry generation through
active-sterile neutrino and antineutrino oscillations in the early universe.
Applications to (i) the suppression of sterile neutrino production, and (ii)
the primordial Helium abundance are briefly presented.


title: Proton spin structure and the low-energy pp -> pp eta' reaction

abstract:
  Gluonic degrees of freedom induce a contact term in the effective chiral
Lagrangian description of the low-energy pp -> pp eta' reaction. The strength
of this contact term is, in part, related to the amount of spin carried by
polarised gluons in a polarised proton.


title: Resolution of the strong CP problem

abstract:
  It is shown that the quark mass aligns QCD $\theta$ vacuum in such a way that
the strong CP is conserved, resolving the strong CP problem.


title:
Radion stabilization in the Randall-Sundrum model with qudratic and
  quartic potentials

abstract:
  In this report we investigate the Goldberger-Wise (GW) mechanism of radion
stabilization with quartic potential on the hidden brane and quadratic
potential on the visible brane. The advantage of our simplified scenario over
the original GW mechanism is that the modulus potential can be evaluated for
finite $\lv$ and $\lh$. This enables us to probe how the modulus potential
behaves over the entire range of $\lh$. By staying away from the GW limit of
${k \over \lv v_v^2} \to $0 and ${k \over \lh v_h^2}\to $0 we show that it is
possible to choose the parameters of the model so that the potential exhibits a
minimum at $k\rc \approx$ 12 and this adjustment does not involve any extreme
fine tuning of parameters.


title: Final state interaction and $B\to KK$ decays in perturbative QCD

abstract:
  We predict branching ratios and CP asymmetries of the $B\to KK$ decays using
perturbative QCD factorization theorem, in which tree, penguin, and
annihilation contributions, including both factorizable and nonfactorizable
ones, are expressed as convolutions of hard six-quark amplitudes with universal
meson wave functions. The unitarity angle $\phi_3= 90^o$ and the $B$ and $K$
meson wave functions extracted from experimental data of the $B\to K\pi$ and
$\pi\pi$ decays are employed. Since the $B\to KK$ decays are sensitive to
final-state-interaction effects, the comparision of our predictions with future
data can test the neglect of these effects in the above formalism. The CP
asymmetry in the $B^\pm\to K^\pm K^0$ modes and the $B_d^0\to K^\pm K^\mp$
branching ratios depend on annihilation and nonfactorizable amplitudes. The
$B\to KK$ data can also verify the evaluation of these contributions.


title: Current Issues in Prompt Photon Production

abstract:
  We give a brief account of recent theoretical developments in prompt photon
production.


title: The nucleon spin structure in a simple quark model

abstract:
  We investigate the spin structure of the nucleon in an extended Jaffe-Lipkin
quark model. In addition to the conventional $3q$ structure, different
$(3q)(Q\bar{Q})$ admixtures in the nucleon wavefunction are also taken into
account. The contributions to the nucleon spin from various components of the
nucleon wavefunction are discussed. The effect due to the Melosh-Wigner
rotation is also studied.


title: Multi-field fermionic preheating

abstract:
  Fermion creation during preheating in the presence of multiple scalar fields
exhibits a range of interesting behaviour relevant to estimating post-inflation
gravitino abundances. We present non-perturbative analysis of this phenomenon
over a 6-dimensional parameter space in an expanding background paying
particular attention to the interplay between instant and direct fermion
preheating. In the broad resonance regime we find that instant fermion
production is sensitive to suppression of the long wavelength scalar field
modes during inflation. Further, the standard scenario of resonant fermionic
preheating through inflaton decay can be significantly modified by instant
preheating, and may even lead to a decrease in the number of fermions produced.
We explicitly include the effects of metric perturbations and demonstrate that
they are important at small coupling but not at strong coupling, due to the
rapid saturation of the Pauli bound.


title: Teeny, tiny Dirac neutrino masses: an unorthodox point of view

abstract:
  There are now strong hints suggesting that neutrinos do have a mass after
all. If they do have a mass, it would have to be tiny. Why is it so? Is it
Dirac or Majorana? Can one build a model in which a teeny, tiny Dirac neutrino
mass arises in a natural way? Can one learn something else other than just
neutrino masses? What are the extra phenomenological consequences of such a
model? These are the questions that I will try to focus on in this talk.


title: Bayesian Analysis

abstract:
  After making some general remarks, I consider two examples that illustrate
the use of Bayesian Probability Theory. The first is a simple one, the
physicist's favorite "toy," that provides a forum for a discussion of the key
conceptual issue of Bayesian analysis: the assignment of prior probabilities.
The other example illustrates the use of Bayesian ideas in the real world of
experimental physics.


title: CP Violation in Exclusive B Decays: Recoil Phase Effect

abstract:
  In the perturbative QCD approach to exclusive B decays to two light mesons,
the leading twist contribution corresponds to those diagrams in the
Lepage-Brodsky expansion in which the would be spectator quark receives its
recoil momentum via one gluon exchange. We show that the resulting amplitude,
which in the spectator model is real, acquires an imaginary part which may be
comparable in size to its real part. Thus, this source of the strong
interaction phase in the amplitude must be taken into account in general to
discuss, reliably, the expectations for CP violation in B decays at any
B-Factory type scenario.


title: Upper bound on the scale of Majorana-neutrino mass generation

abstract:
  We derive a model-independent upper bound on the scale of Majorana-neutrino
mass generation. The upper bound is $4\pi v^2/\sqrt 3 m_\nu$, where $v \simeq
246$ GeV is the weak scale and $m_\nu$ is the Majorana neutrino mass. For
neutrino masses implied by neutrino oscillation experiments, all but one of
these bounds are less than the Planck scale, and they are all within a few
orders of magnitude of the grand-unification scale.


title: Coherent Exclusive Exponentiation For Precision Monte Carlo Calculations

abstract:
  We present the new Coherent Exclusive Exponentiation (CEEX), the older
Exclusive Exponentiation (EEX) and the semi-analytical Inclusive Exponentiation
(IEX) for the process $e^+e^-\to f\bar{f} +n\gamma$, $f=\mu,\tau,d,u,s,c,b$
with validity for centre of mass energies from $\tau$ lepton threshold to 1TeV,
that is for LEP1, LEP2, SLC, future Linear Colliders, $b,c,\tau$-factories etc.
They are based on Yennie-Frautschi-Suura exponentiation. In CEEX effects due to
photon emission from initial beams and outgoing fermions are calculated in QED
up to second-order, including all interference effects. Electroweak corrections
are included in first-order, at the amplitude level. Beams can be polarized
longitudinally and transversely, and all spin correlations are incorporated in
an exact manner. EEX is more primitive, lacks initial-final interferences, but
it is valuable for testing the newer CEEX. IEX provides us set of a
sophisticated semi-analytical formulas for the total cross section and selected
inclusive distributions which are mainly used for cross-checks of the MC
results. We analyse numerical results at the Z-peak 189 GeV and 500 GeV for
simple kinematical cuts (comparisons with IEX) and for realistic experimental
cuts. Physical precision and technical precision are determined for the total
cross section and for the charge asymmetry.


title: Neutrino Masses at v^{3/2}

abstract:
  Theories in which neutrino masses are generated by a conventional see-saw
mechanism generically yield masses which are O(v^2) in units where M_{Pl}=1,
which is naively too small to explain the results from SuperKamiokande. In
supersymmetric theories with gravity mediated supersymmetry breaking, the
fundamental small parameter is not v/M_{Pl}, but m_I/M_{Pl}, where m_I is the
scale of supersymmetry breaking in the hidden sector. We note that
m_I^3/M_{Pl}^2 is only slightly too large to explain SuperKamiokande, and
present two models that achieve neutrino masses at this order in m_I, one of
which has an additional suppression lambda_tau^2, while the other has
additional suppression arising from a loop factor. The latter model shares a
great deal of phenomenology with a class of models previously explored,
including the possibility of viable sneutrino dark matter.


title: Higgs-Boson Production and Decay Close to Thresholds

abstract:
  At one loop in the conventional on-mass-shell renormalization scheme, the
production and decay rates of the Higgs boson H exhibit singularities
proportional to (2 M_V - M)^{-1/2} as the Higgs-boson mass M approaches from
below the pair-production threshold of a vector boson V with mass M_V. This
problem is of phenomenological interest because the values 2 M_W and 2 M_Z,
corresponding to the W- and Z-boson thresholds, lie within the M range
presently favoured by electroweak precision data. We demonstrate how these
threshold singularities are eliminated when the definitions of mass and total
decay width of the Higgs boson are based on the complex-valued pole of its
propagator. We illustrate the phenomenological implications of this
modification for the partial width of the H -> W^+ W^- decay.


title: Quarkonium Decays and Production in NRQCD

abstract:
  Some examples of the most recent applications of the NRQCD factorization
approach to quarkonium phenomenology are presented. In the first part of the
talk the NLO calculations for $\chicj$ and $\Upsilon$ decays rates are compared
to the data and the results critically analyzed. In the second part, I show how
information on the non-perturbative matrix elements can be extracted from the
hadronic fixed-target experiments and eventually used to test their
universality.


title: Photo-Transmutation of Leptons

abstract:
  By photo-transmutation of leptons we mean photon-lepton reactions of the
following type: $\gamma l_\alpha \longrightarrow \gamma l_\beta$ with $l_\alpha
\neq l_\beta$, occurring as a consequence of the lepton mass matrix changing
its orientation (rotating) under changing scales. In this paper, we first
discuss these reactions in general terms, then proceed to the calculation of
their cross sections in two specific schemes, one within the framework of the
conventional Standard Model, the other being the so-called Dualized Standard
Model we ourselves advocate. Although the cross section obtained is generally
small the calculation reveals certain special circumstances where these
reactions may be accessible to experiment, for example with virtual photons in
LEP for $\gamma e \longrightarrow \gamma \tau$, and in BEPC for $\gamma e
\longrightarrow \gamma \mu$.


title: On power corrections to the event shape distributions in QCD

abstract:
  We study power corrections to the differential thrust, heavy jet mass and
C-parameter distributions in the two-jet kinematical region in e^+e^-
annihilation. We argue that away from the end-point region, e>>
\Lambda_{QCD}/Q, the leading 1/Q-power corrections are parameterized by a
single nonperturbative scale while for e \Lambda_{QCD}/Q one encounters a novel
regime in which power corrections of the form 1/(Qe)^n have to be taken into
account for arbitrary n. These nonperturbative corrections can be resummed and
factor out into a universal nonperturbative distribution, the shape function,
and the differential event shape distributions are given by convolution of the
shape function with perturbative cross-sections. Choosing a simple ansatz for
the shape function we demonstrate a good agreement of the obtained QCD
predictions for the distributions and their lowest moments with the existing
data over a wide energy interval.


title:
SUSY-QCD corrections to the MSSM $h^0 b \bar b$ vertex in the decoupling
  limit

abstract:
  We analyze the supersymmetric (SUSY) QCD contribution to the $h^0 b \bar{b}$
coupling at one loop in the Minimal Supersymmetric Model (MSSM) in the
decoupling limit. Analytic expressions in the large SUSY mass region are
derived and the decoupling behavior of the corrections is examined in various
limiting cases, where some or all of the SUSY mass parameters become large. We
show that in the decoupling limit of large SUSY mass parameters and large
CP-odd Higgs mass, the $h^0 b \bar b$ coupling approaches its Standard Model
value at one loop. However, the onset of decoupling is delayed when $\tan\beta$
is large. In addition, the one-loop SUSY-QCD corrections decouple if the masses
of either the bottom squarks or the gluino are separately taken large; although
the approach to decoupling is significantly slower in the latter case.


title:
Initial-Final State Subspace of the SU(n) Gauge Theory with Explicit
  Gauge Field Mass Term

abstract:
  As a part of our study on the SU(n) gauge theory with explicit gauge field
mass term this paper is devoted to form the Gupta-Bleuler subspace of the
initial-final states in the scattering process.


title: The radion contribution to the weak mixing angle

abstract:
  In the Randall-Sundrum (RS) compactification, the gap between two branes is
stabilized by the vacuum expectation value of a scalar field called {\it
radion}, $\phi$. This radion behaves like a weak interaction singlet scalar
field, coupling to matter through the trace of the energy momentum tensor. We
find that it can induce a sizable correction to the weak mixing angle if the
vacuum expectation value and the mass of the radion is around TeV. We also
comment on the contribution to the $K_L-K_S$ mass difference and to
$(g-2)_\mu$.


title:
Measuring sparticle masses in non-universal string inspired models at
  the LHC

abstract:
  We demonstrate that some of the suggested five supergravity points for study
at the LHC could be approximately derived from perturbative string theories or
M-theory, but that charge and colour breaking minima would result. As a pilot
study, we then analyse a perturbative string model with non-universal soft
masses that are optimised in order to avoid global charge and colour breaking
minima. By combining measurements of up to six kinematic edges from squark
decay chains with data from a new kinematic variable, designed to improve
slepton mass measurements, we demonstrate that a typical LHC experiment will be
able to determine squark, slepton and neutralino masses with an accuracy
sufficient to permit an optimised model to be distinguished from a similar
standard SUGRA point. The technique thus generalizes SUSY searches at the LHC.


title: Anomalous magnetic moment of muon in 3-3-1 models

abstract:
  A contribution from new gauge bosons in the ${SU}(3)_C\otimes {SU}(3)_L
\otimes {U}(1)_N$ (3 - 3 - 1) models to the anomalous magnetic moments of the
muon is calculated and numerically estimated. In the minimal 3 - 3 - 1 model, a
lower bound on the bilepton mass at a value of 167 GeV is derived. For an
expected precision($\sim 4\times 10^{-10}$) of the BNL measurements the
possible lower bounds on masses of the bileptons in the minimal version and in
the version with right-handed neutrinos are around 940 GeV and 250 GeV,
respectively.

categories: hep-ph cond-mat physics.atom-ph quant-ph


title: A neutrino mass matrix with seesaw mechanism and two-loop mass splitting

abstract:
  We propose a model which uses the seesaw mechanism and the lepton number
$\bar L = L_e - L_\mu - L_\tau$ to achieve the neutrino mass spectrum $m_1 =
m_2$ and $m_3 = 0$, together with a lepton mixing matrix $U$ with $U_{e3} = 0$.
In this way, we accommodate atmospheric neutrino oscillations. A small mass
splitting $m_1 > m_2$ is generated by breaking $\bar L$ spontaneously and using
Babu's two-loop mechanism. This allows us to incorporate ``just so''
solar-neutrino oscillations with maximal mixing into the model. The resulting
mass matrix has three parameters only, since $\bar L$ breaking leads
exclusively to a non-zero $ee$ matrix element.


title:
Precision Predictions for (Un)Stable W+W- Pair Production At and Beyond
  LEP2 Energies Beyond LEP2 Energies

abstract:
  We present precision calculations of the processes e+e- -> 4-fermions in
which the double resonant W+W- intermediate state occurs. Referring to this
latter intermediate state as the 'signal process', we show that, by using the
YFS Monte Carlo event generators YFSWW3-1.14 and KORALW1.42 in an appropriate
combination, we achieve a physical precision on the signal process, as isolated
with LEP2 MC Workshop cuts, below 0.5 per cent. We stress the full gauge
invariance of our calculations and we compare our results with those of other
authors where appropriate. In particular, sample Monte Carlo data are
explicitly illustrated and compared with the results of the program RacoonWW of
Dittmaier {\it et al.}. In this way, we show that the total (physical plus
technical) precision tag for the WW signal process cross section is 0.4 per
cent for 200 GeV, for example. Results are also given for 500 GeV with an eye
toward the LC.


title: Integrability of twist-three evolution equations in QCD

abstract:
  We describe a recent progress in finding solutions to three-particle
evolution equations at leading order in the QCD coupling constant for
multiparton correlation functions based on the integrability of corresponding
interaction Hamiltonians.


title:
Single spin asymmetries in $\gamma^* \gamma \to \pi \pi \pi$ at large
  Q^2

abstract:
  The $\gamma^* \gamma \to \pi \pi \pi$ reaction is analysed in QCD at large
photon virtuality Q and small hadronic mass W. Its amplitude factorizes in a $3
\pi$ generalized distribution amplitude and a hard subprocess $\gamma^* \gamma
\to q \bar q$ or $\gamma^* \gamma \to g g$. The interference of this process
with a Brehmsstrahlung process in e e or $e \gamma$ collisions gives rise to
interesting single spin asymmetries, particularly when W is near the $\omega$
mass.


title: Equation of state of cosmic strings with fermionic current-carriers

abstract:
  The relevant characteristic features, including energy per unit length and
tension, of a cosmic string carrying massless fermionic currents in the
framework of the Witten model in the neutral limit are derived through
quantization of the spinor fields along the string. The construction of a Fock
space is performed by means of a separation between longitudinal modes and the
so-called transverse zero energy solutions of the Dirac equation in the vortex.
As a result, quantization leads to a set of naturally defined state parameters
which are the number densities of particles and anti-particles trapped in the
cosmic string. It is seen that the usual one-parameter formalism for describing
the macroscopic dynamics of current-carrying vortices is not sufficient in the
case of fermionic carriers.


title: Can R-parity violation explain the LSND data as well?

abstract:
  The recent Super-Kamiokande data now admit only one type of mass hierarchy in
a framework with three active and one sterile neutrinos. We show that neutrino
masses and mixings generated by R-parity-violating couplings, with values
within their experimental upper limits, are capable of reproducing this
hierarchy, explaining all neutrino data particularly after including the LSND
results.


title: Final State Interactions in $\epsilon'/\epsilon$

abstract:
  Strong final state interaction (FSI) effects can play a central role in the
Standard Model prediction of weak $K\to 2\pi$ matrix elements. Here, I discuss
how FSI's affect the direct CP violation parameter $\vepp / \vep$ by solving
the Omn\`es problem for the necessary $K\to 2\pi$ amplitudes. The main results
of this analysis have been reported in a previous paper [1] and are further
discussed in Refs. [2,3]. The resulting Standard Model prediction ${Re} (\vepp
/ \vep) = (15\pm 5)\times 10^{-4}$ is in good agreement with the present
experimental world average.


title: Low-Scale See-Saw Mechanisms for Light Neutrinos

abstract:
  Alternatives to the see-saw mechanism are explored in supersymmetric models
with three right-handed or sterile neutrinos. Tree-level Yukawa couplings can
be drastically suppressed in a natural way to give sub-eV Dirac neutrino
masses. If, in addition, a B-L gauge symmetry broken at a large scale M_G is
introduced, a wider range of possibilities opens up. The value of the
right-handed neutrino mass M_R can be easily disentangled from that of M_G.
Dirac and Majorana neutrino masses at the eV scale can be generated radiatively
through the exchange of sneutrinos and neutralinos. Dirac masses m_D owe their
smallness to the pattern of light-heavy scales in the neutralino mass matrix.
The smallness of the Majorana masses m_L is linked to a similar see-saw pattern
in the sneutrino mass matrix. Two distinct scenarios emerge. In the first, with
very small or vanishing M_R, the physical neutrino eigenstates are, for each
generation, either two light Majorana states with mixing angle ranging from
very small to maximal, depending on the ratio m_D/M_R, or one light Dirac
state. In the second scenario, with a large value of M_R, the physical
eigenstates are two nearly unmixed Majorana states with masses \sim m_L and
\sim M_R. In both cases, the (B-L)-breaking scale M_G is, in general, much
smaller than that in the traditional see-saw mechanism.


title: Analyzing the 't Hooft Model on an x+ - p+ Lattice

abstract:
  We study the 't Hooft model (large N_c QCD in 2 space-time dimensions) using
an improved approach to digitizing the sum of gauge theory Feynman diagrams
based on light-cone gauge A+=0 and discretized p+ and ix+. Our purpose is to
test the new formalism in a solvable case, with the hope to gain some insight
into how it might be usefully applied to the physically interesting case of 4
dimensional QCD.


title: Bounds on Bosonic Topcolor

abstract:
  We consider the phenomenology of models in which electroweak symmetry
breaking is triggered by new strong dynamics affecting the third generation and
is transmitted to the light fermions via a fundamental Higgs doublet. While
similar in spirit to the old bosonic technicolor idea, such `bosonic topcolor'
models are allowed by current phenomenological constraints, and may arise
naturally in models with large extra dimensions. We study the parameter space
of a minimal low-energy theory, including bounds from Higgs boson searches,
precision electroweak parameters, and flavor changing neutral current
processes. We show that the model can provide a contribution to D0-D0-bar
mixing as large as the current experimental bound.


title: New inflation in supergravity with a chaotic initial condition

abstract:
  We propose a self-consistent scenario of new inflation in supergravity.
Chaotic inflation first takes place around the Planck scale, which solves the
longevity problem, namely, why the universe can live much beyond the Planck
time, and also gives an adequate initial condition for new inflation. Then, new
inflation lasts long enough to generate primordial fluctuations for the large
scale structure, which generally has a tilted spectrum with the spectral index
$n_{s} < 1$. The successive decay of the inflaton leads to the reheating
temperature low enough to avoid the overproduction of gravitinos in a wide
range of the gravitino mass.


title: Spin structure of the octet baryons

abstract:
  We analyze the semileptonic weak decays of the octet baryons in a "{\em model
independent}" approach, based on the algebraic structure of the Chiral
Quark-Soliton Model. We argue that this analysis is in fact more general than
the model itself. While the symmetry breaking for the semileptonic decays
themselves is not strong, other quantities like $\Delta s$ and $\Delta \Sigma$
are much more affected. We calculate $\Delta \Sigma$ and $\Delta q$ for all
octet baryons. Unfortunately, large experimental errors of $\Xi^-$ decays
propagate in our analysis, in particular, in the case of $\Delta\Sigma $ and
$\Delta s$. Only if the errors for these decays are reduced, the accurate
theoretical predictions for $\Delta\Sigma$ and $\Delta s$ will be possible.


title: Vacuum instability in the Abelian Higgs model with strings

abstract:
  Using the effective potential approach for composite operators, we have
analytically evaluated the truly nonperturbative vacuum energy density in the
Abelian Higgs model of dual QCD ground state. This quantity is defined as
integrating out of the truly nonperturbative part of the full gluon propagator
over the deep infrared region (soft momentum region). Defined in this way it is
manifestly gauge invariant.We have explicitly shown that the corresponding
effective potential always has an imaginary part. This means that the vacuum of
this model with string contributions is unstable against quantum corrections.


title: A Phenomenological Estimate of the Binding Energy of Heavy Dimesons

abstract:
  A phenomenological estimate is derived such that the binding energies of
dimesons are expressed as combinations of masses of different mesons and
baryons. The estimate is almost model-independent, the only major assumptions
being that the wave functions of the two light quarks in $\Lambda_c$,
$\Lambda_b$ and in the $\bar{c}\bar{c}qq$ and $\bar{b}\bar{b}qq$ dimesons are
very similar, and that for heavy quarks the $QQ$ interaction is half as strong
as the $Q\bar{Q}$ interaction. We get $\bar{b}\bar{b}qq$ (I=0, J=1) bound by
about 100 MeV and $\bar{c}\bar{c}qq$ unbound.


title:
Unitarity triangles and geometrical description of CP violation with
  Majorana neutrinos

abstract:
  We generalize the geometrical description of CP violation in the Standard
Model in terms of a unitarity triangle. For three left-handed Majorana
neutrinos CP violation in the lepton sector is determined by three unitarity
triangles. With three additional right-handed neutrinos 15 quadrangles are
required to characterize CP violation. We show the relation of the unitarity
polygons with physical observables.


title: Future High Q^2 Deep Inelastic Scattering at HERA

abstract:
  The luminosity of the electron-proton collider, HERA, will be increased by a
factor of five during the long shutdown starting September 2000. At the same
time longitudinal lepton beam polarisation will be provided for the collider
experiments H1 and ZEUS. These far reaching upgrades to the machine will be
matched by upgrades to the detectors. The result will be a unique facility for
the study of the structure of the proton and the nature of the strong and
electroweak interactions. The physics potential of the upgraded accelerator is
discussed here.


title: Absorption of Electro-magnetic Waves in a Magnetized Medium

abstract:
  In continuation to our earlier work, in which the structure of the vacuum
polarisation tensor in a medium was analysed in presence of a background
electro-magnetic field, we discuss the absorptive part of the vacuum
polarization tensor. Using the real time formalism of finite temperature field
theory we calculate the absorptive part of 1-loop vacuum polarisation tensor in
the weak field limit ($eB < m^2$). Estimates of the absorption probability are
also made for different physical conditions of the background medium.


title:
Thermal Freeze-out and Longitudinally Non-uniform Collective Expansion
  Flow in Relativistic Heavy Ion Collisions

abstract:
  The non-uniform longitudinal flow model (NUFM) propsed recently is extended
to include also transverse flow. The resulting longitudinally non-uniform
collective expansion model (NUCEM) is applied to the calculation of rapidity
distribution of kaons, lambdas and protons in relativistic heavy ion collisions
at CERN-SPS energies. The model results are compared with the 200 A GeV/$c$ S-S
and 158 A GeV/$c$ Pb-Pb collision data. The central dips observed in
experiments are reproduced in a natural way.


title: Reply to ``Is $U_{e3}$ really related to the solar neutrino solutions?''

abstract:
  In a recent paper [1] we showed that, assuming no fine tuning between certain
elements of the neutrino mass matrix, one can link the element U_{e3} of the
lepton mixing matrix to solar and atmospheric neutrino oscillation parameters.
This result has been recently criticized by Haba and Suzuki [2]. In the present
note we show that their criticism is not valid and just reflects their failure
to understand the content of our paper.


title: String Representation of Gauge Theories

abstract:
  In this talk, various approaches to the problem of evaluation of the field
strength correlators in the SU(3)-gluodynamics, which play the major role in
the Stochastic Vacuum Model, are reviewed. This is done in the framework of the
effective Abelian-projected theories under the various assumptions implied on
the properties of the ensemble of Abelian-projected monopoles. In particular,
within the assumption on the condensation of the monopole Cooper pairs, the
main method of investigation is the string representation of field strength
correlators. The calculation of the bilocal field strength correlator in the 3D
effective theory, where Abelian-projected monopoles are assumed to form a gas,
based on the string representation for the Wilson loop in this theory, is also
presented.


title: Twist-three effects in two-photon processes

abstract:
  We give a general treatment of twist-three effects in two-photon reactions.
We address the issue of the gauge invariance of the Compton amplitude in
generalized Bjorken kinematics and relations of twist-three `transverse' skewed
parton distributions to twist-two ones and interaction dependent three-particle
correlation functions. Finally, we discuss leading order evolution of
twist-three functions and their impact on the deeply virtual Compton
scattering.


title:
Analytical Result for Dimensionally Regularized Massless Master Double
  Box with One Leg off Shell

abstract:
  The dimensionally regularized massless double box Feynman diagram with powers
of propagators equal to one, one leg off the mass shell, i.e. with non-zero
q^2=p_1^2, and three legs on shell, p_i^2=0, i=2,3,4, is analytically
calculated for general values of q^2 and the Mandelstam variables s and t. An
explicit result is expressed through (generalized) polylogarithms, up to the
fourth order, dependent on rational combinations of q^2,s and t, and a
one-dimensional integral with a simple integrand consisting of logarithms and
dilogarithms.


title:
Neutrino Self-Energy and Index of Refraction in Strong Magnetic Field: A
  New Approach

abstract:
  The Ritus' $E_{p}$ eigenfunction method is extended to the case of spin-1
charged particles in a constant electromagnetic field and used to calculate the
one-loop neutrino self-energy in the presence of a strong magnetic field.From
the obtained self-energy, the neutrino dispersion relation and index of
refraction in the magnetized vacuum are determined within the field range
$m_{e}^{2}\ll eB\ll M_{W}^{2}$. The propagation of neutrinos in the magnetized
vacuum is anisotropic due to the dependence of the index of refraction on the
angle between the directions of the neutrino momentum and the external field.
Possible cosmological implications of the results are discussed.


title: Pi0 -> Gamma Gamma in Dense QCD

abstract:
  QCD superconductors in the color-flavor-locked (CFL) phase support light
excitations (generalized pions) in the form of particle-particle or hole-hole
excitations. We analyze the generalized process
$\tilde\pi^0\to\tilde{\gamma}\tilde{\gamma}$ in the weak coupling limit and
show that it is related to the recently suggested Wess-Zumino-Witten (WZW)
term. In dense QCD, the radiative decay of the generalized pion is constrained
by geometry and vanishes at large density.


title: Baryonic resonances mass spectrum from a modified perturbative QCD

abstract:
  A recently proposed modified perturbation expansion for QCD is employed to
evaluate the quark self-energies. Results of the order of 1/3 of the nucleon
mass are obtained for the effective masses of the up and down quarks in a first
approximation. Also, the predicted flavor dependence of the calculated quarks
masses turns out to be the appropriate to well reproduce the spectrum of the
ground states within the various groups of hadronic resonances through the
simple addition of the evaluated constituent quark masses. The results suggests
to conjecture that the modified expansion, after also introducing quark
condensates in a same token as the gluonic ones, would be able to furnish a
natural explanation of the mass spectrum of the three generations of
fundamental fermions.


title:
Off-forward parton distributions and impact parameter dependence of
  parton structure

abstract:
  The connection between parton distributions as a function of the impact
parameter and off-forward parton distributions is discussed in the limit of
vanishing skewedness parameter $\zeta$, i.e. when the off-forwardness is purely
transverse. For the $2^{nd}$ moment it is also illustrated how to relate
$\zeta\neq 0$ data to $\zeta=0$ data, which is important for experimental
measurements of these observables.


title:
Out of equilibrium O (N) linear-sigma system - Construction of
  perturbation theory with gap- and Boltzmann-equations

abstract:
  We establish from first principles a perturbative framework that allows us to
compute reaction rates for processes taking place in nonequilibrium $O (N)$
linear-sigma systems in broken phase. The system of our concern is quasiuniform
system near equilibrium or nonequilibrium quasistationary system. We employ the
closed-time-path formalism and use the so-called gradient approximation. No
further approximation is introduced. In the course of construction of the
framework, we obtain the gap equation that determines the effective masses of
$\pi$ and of $\sigma$, and the generalized Boltzmann equation that describes
the evolution of the number-density functions of $\pi$ and of $\sigma$.


title: B ->PV Decays in the QCD Improved Factorization Approach

abstract:
  Motivated by recent CELO measurements and the progress of the theory of B
decays, we investigate $B\to P V(P=\pi,K. V= K^{*},\rho,\omega)$ decay modes in
the framework of QCD improved factorization. We find that all the measured
branching ratios are well accommodated in the reasonable parameter space and
predictions for the other decay modes are well below the experimental upper
limits. We also have calculated CP asymmetries in these decay modes.


title: The b--> s g g decay in the general two Higgs doublet model

abstract:
  We study the decay width of the inclusive process b --> s g g in the two
Higgs doublet model with three level flavor changing neutral currents (model
III). We analyse the dependencies of the differential decay width to the s
quark energy E_s and model III parameters, charged Higgs mass m_{H^{\pm}} and
Yukawa coupling \bar{\xi}_{N,bb}^D. We observe that there exist a considerable
enhancement in the decay width for the relevant process. This enhancement can
be reduced by choosing C_7^{eff} as negative and increasing the lower bound of
m_{H^{\pm}} to the large values, such as 800 GeV . This is an interesting
result which gives an idea on the mass m_{H^{\pm}} and sign of C_7^{eff}.


title:
What is the Standard Model of Elementary Particles and Why We Have to
  Modify It

abstract:
  We introduce the standard model of elementary particles and discuss the
reasons why we have to modify it. Emphasis is put on the indications from the
neutrinos and on the role of the Higgs particle; some promising theoretical
ideas, like quark-lepton symmetry, existence of super-heavy ``right-handed''
neutrinos, grand unification and supersymmetry at the weak scale, are
introduced and shortly discussed.


title:
Constraints on both bilinear and trilinear R-parity violating couplings
  from neutrino laboratories and astrophysics data

abstract:
  We consider neutrino masses generated at tree level and at one loop, through
fermion--sfermion loop diagrams, in the MSSM with R-parity violation. Using the
$(3\times 3)$ mass and mixing matrices for three generations of neutrinos and
the present experimental results on neutrinos from laboratories and
astrophysics simultaneously, we put bounds on both trilinear ($\lambda_{ijk},
\lambda'_{ijk}$) and bilinear ($\mu_{e},\mu_\mu,\mu_\tau$) R-parity-violating
couplings.


title: Nucleon Spin Structure Functions

abstract:
  The review of the nucleon spin structure functions problems is presented. The
perturbative QCD predictions for the small x behaviour of the nucleon spin
structure functions are discussed. The role of the resummation of the ln^2 1/x
terms is emphasized. Predictions for the nonsinglet structure function g_1 in
case of a flat as well as a dynamical input are given. The so called "spin
crisis" on the context of both theoretical and experimental future hopes are
also briefly discussed.


title: Inflaton Particles in Reheating

abstract:
  In many theories of reheating starting from the classical spatially
homogeneous inflaton field, its accompanying inhomogeneous part (which arises
from primordial quantum fluctuations) is treated as a first order perturbation.
We examine some consequences of treating it non-perturbatively in a model where
a first order treatment is invalid. In particular we consider effects on the
long-wavelength curvature parameter relevant to the cosmic microwave background
fluctuations.


title: Proton polarizability contribution to the hydrogen hyperfine splitting

abstract:
  The contribution of the proton polarizability to the hydrogen hyperfine
splitting is evaluated on the basis of modern experimental and theoretical
results on the proton polarized structure functions. The value of this
correction is equal to 1.4 ppm.


title: Domain Walls in SU(5)

abstract:
  We consider the Grand Unified SU(5) model with a small or vanishing cubic
term in the adjoint scalar field in the potential. This gives the model an
approximate or exact Z$_2$ symmetry whose breaking leads to domain walls. The
simplest domain wall has the structure of a kink across which the Higgs field
changes sign ($\Phi \to -\Phi$) and inside which the full SU(5) is restored.
The kink is shown to be perturbatively unstable for all parameters. We then
construct a domain wall solution that is lighter than the kink and show it to
be perturbatively stable for a range of parameters. The symmetry in the core of
this domain wall is smaller than that outside. The interactions of the domain
wall with magnetic monopole is discussed and it is shown that magnetic
monopoles with certain internal space orientations relative to the wall pass
through the domain wall. Magnetic monopoles in other relative internal space
orientations are likely to be swept away on collision with the domain walls,
suggesting a scenario where the domain walls might act like optical
polarization filters, allowing certain monopole ``polarizations'' to pass
through but not others. As SU(5) domain walls will also be formed at small
values of the cubic coupling, this leads to a very complicated picture of the
evolution of defects after the Grand Unified phase transition.


title: Predictions for Fermion Pair Production at e+e- Colliders

abstract:
  We discuss the status and some ongoing upgrades of the ZFITTER program for
applications at e+e- colliders LEP1/SLC, LEP2, GigaZ, and TESLA. The inclusion
of top quark pair production is under work.


abstract:
  Transversely polarized Lambda production in hard scattering processes is
discussed in terms of a leading twist T-odd fragmentation function which
describes the fragmentation of an unpolarized quark into a transversely
polarized Lambda. We focus on the properties of this function and its relevance
for the RHIC and HERMES experiments.


title:
Ultraviolet dependence of Kaluza-Klein effects on electroweak
  observables

abstract:
  In extensions of the standard model (SM) with d extra dimensions at the TeV
scale the virtual exchange of Kaluza-Klein (KK) excitations of the gauge bosons
gives contributions that change the SM relations between electroweak
observables. These corrections are finite only for d=1; for d\ge 2 the infinite
tower of KK modes gives a divergent contribution that has to be regularized
introducing a cutoff (the string scale). However, the ultraviolet dependence of
the KK effects is completely different if the running of the couplings with the
scale is taken into account. We find that for larger d the number of
excitations at each KK level increases, but their larger number is compensated
by the smaller value of the gauge coupling at that scale. As a result, for any
number of extra dimensions the exchange of the complete KK tower always gives a
finite contribution. We show that (i) for d=1 the running of the gauge coupling
decreases an 14% the effect of the KK modes on electroweak observables; (ii) in
all cases more than 90% of the total effect comes from the excitations in the
seven lowest KK levels and is then independent of ultraviolet physics.


title:
Instanton Effects on the Role of the Low-Energy Theorem for the Scalar
  Gluonic Correlation Function

abstract:
  Instanton contributions to the Laplace sum-rules for correlation functions of
scalar gluonic currents are calculated. The role of the constant low-energy
theorem term, whose substantial contribution is unique to the leading Laplace
sum-rule $L_{-1}$, is shown to be diminished by instanton contributions,
significantly increasing the resulting mass bounds for the ground state of
scalar gluonium and improving compatibility with results from higher-weight
sum-rules.


title:
Next-to-Leading Order Corrections to Heavy Flavour Production in
  Longitudinally Polarized Photon-Nucleon Collisions

abstract:
  A complete next-to-leading order calculation of longitudinally polarized
heavy quark photoproduction is presented. All results of the purturbative
calculation are given in detail. For reactions and energies of interest cross
sections differential in the transverse momentum and rapidity of the heavy
quark, total cross sections and the corresponding asymmetries are given. Errors
in the asymmetries are estimated and the possibility to distinguish between
various scerarios of the polarized gluon distribution is discussed. Our results
are compared with other related publications.


title: Jets in Hadron Collisions

abstract:
  We discuss recent progress and open questions in QCD jet physics, with
particular emphasis on two areas: jet definitions and jet substructure.


title: Luminosity of Asymmetric e+e- Collider with Coupling Lattices

abstract:
  A formula of luminosity of asymmetric e+e- collider with coupled lattices is
derived explicitly. The calculation shows how the tilted angle and aspect ratio
of the beams affect the luminosity. Knowing the result of the calculation, we
measure the tilted angle of the luminous region of the collision for PEP-II
using two dimensional transverse scan of the luminosity. The method could be
applied to correct the coupling at the collision point.


title: Automatic Computation of Cross Sections in HEP

abstract:
  For the study of reactions in High Energy Physics (HEP) automatic computation
systems have been developed and are widely used nowadays. GRACE is one of such
systems and it has achieved much success in analyzing experimental data. Since
we deal with the cross section whose value can be given by calculating hundreds
of Feynman diagrams, we manage the large scale calculation, so that effective
symbolic manipulation, the treat of singularity in the numerical integration
are required. The talk will describe the software design of GRACE system and
computational techniques in the GRACE.


title: On |V_{ub}| from the B -> X_u l \nu dilepton invariant mass spectrum

abstract:
  The invariant mass spectrum of the lepton pair in inclusive semileptonic
$\bar B\to X_u \ell\bar\nu$ decay yields a model independent determination of
$|V_{ub}|$. Unlike the lepton energy and hadronic invariant mass spectra,
nonperturbative effects are only important in the resonance region, and play a
parametrically suppressed role when $d\Gamma / dq^2$ is integrated over $q^2 >
(m_B-m_D)^2$, which is required to eliminate the $\bar B\to X_c \ell\bar\nu$
background. We discuss these backgrounds for $q^2$ slightly below
$(m_B-m_D)^2$, and point out that instead of $q^2 > (m_B-m_D)^2 = 11.6 GeV^2$,
the cut can be lowered to $q^2 \gtrsim 10.5 GeV^2$. This is important
experimentally, particularly when effects of a finite neutrino reconstruction
resolution are included.


title:
Factorization Scheme and Parton Distributions in the Polarized Virtual
  Photon Target

abstract:
  We investigate spin-dependent parton distributions in the polarized virtual
photon target in perturbative QCD up to the next-to-leading order (NLO). In the
case $\Lambda^2 \ll P^2 \ll Q^2$, where $-Q^2$ ($-P^2$) is the mass squared of
the probe (target) photon, parton distributions can be predicted completely up
to NLO, but they are factorization-scheme-dependent.We analyze parton
distributions in six different factorization schemes and discuss their scheme
dependence. We study, in particular, the QCD and QED axial anomaly effects on
the first moments of parton distributions to see the interplay between the
axial anomalies and factorization schemes. We also show that the
factorization-scheme dependence is characterized by the large-$x$ behaviors of
quark distributions in the virtual photon. Gluon distribution is predicted to
be the same up to NLO among the six factorization schemes examined. In
particular, the first moment of gluon distribution is found to be
factorization-scheme independent up to NLO.


title: Low energy analysis of the nucleon electromagnetic form factors

abstract:
  We analyze the electromagnetic form factors of the nucleon to fourth order in
relativistic baryon chiral perturbation theory. We employ the recently proposed
infrared regularization scheme and show that the convergence of the chiral
expansion is improved as compared to the heavy fermion approach. We also
discuss the inclusion of vector mesons and obtain an accurate description of
all four nucleon form factors for momentum transfer squared up to Q^2 \simeq
0.4 GeV^2.


title: Testing Lorentz invariance violations in the tritium beta-decay anomaly

abstract:
  We consider a Lorentz non-invariant dispersion relation for the neutrino,
which would produce unexpected effects with neutrinos of few eV, exactly where
the tritium beta-decay anomaly is found. We use this anomaly to put bounds on
the violation of Lorentz invariance. We discuss other consequences of this
non-invariant dispersion relation in neutrino experiments and high-energy
cosmic-ray physics.


title: Single Top Quark in the SM and Beyond

abstract:
  The prospects of single top quark physics at colliders of the TeV energy
scale are discussed. Single top quark study allows a direct measurement of the
$Wtb$ vertex and a precise probing physics beyond the Standard Model in various
scenarios.


title:
B and B_s decays into three pseudoscalar mesons and the determination of
  the angle gamma of the unitarity triangle

abstract:
  We reconsider two classical proposals for the determination of the angle
gamma of the unitarity triangle: B^\pm => chi_{c0} \pi^\pm => \pi^+\pi^-\pi^\pm
and B_s => rho^0 K_S => \pi^+ \pi^- K_S. We point out the relevance, in both
cases, of non resonant amplitudes, where the \pi^+ \pi^- pair is produced by
weak decay of a B^* (J^P=1^-) or B_0 (J^P=0^+) off-shell meson. In particular,
for the B decay channel, the inclusion of the B_0 pole completes some previous
analyses and confirms their conclusions, provided a suitable cut in the Dalitz
plot is performed; for the B_s decay the inclusion of the B^*, B_0 amplitudes
enhances the role of the tree diagrams as compared to penguin amplitudes, which
makes the theoretical uncertainty related to the B_s => rho^0 K_S decay process
less significant. While the first method is affected by theoretical
uncertainties, the second one is cleaner, but its usefulness will depend on the
available number of events to perform the analysis.


title: Wavelet-patterns in nucleus-nucleus collisions at 158A GeV

abstract:
  We propose to use {\it multidimensional} \w \an for pattern recognition in
high multiplicity events and consider some examples. Wavelet analysis reveals
clustering phenomena in multiparticle production processes. Results of
event-by-event studies of some nucleus-nucleus collisions at 158A GeV are
reported. The clusterization topology is found to be different in different
events. Typical patterns include jets and ring-like structures. They are
demonstrated here for five high multiplicity events.


title: Strong Isospin Breaking in CP-even and CP-odd K -> pi pi Decays

abstract:
  Complete next-to-leading (chiral) order (NLO) expressions for the strong
isospin-breaking (IB) contributions in K -> pi pi are used to discuss (1) for
CP-even, the impact on the magnitude of the Delta I=1/2 Rule, and (2) for
CP-odd, the strong IB correction, Omega_st, for the gluonic penguin
contribution to epsilon'/epsilon, with particular emphasis on the strong
low-energy constant (LEC) and loop contributions, numerical values for which
are model-independent at NLO.


title: Complete one-loop corrections to e+ e- -> W+ W- in the MSSM

abstract:
  The complete O(\alpha) corrections including soft-photon bremsstrahlung to
the process e^+ e^- -> W^+ W^- in the MSSM are calculated for on-shell W
bosons. The relative difference between the MSSM and Standard Model corrections
is generally quite small. The maximum deviation from the Standard Model within
the scanned region of parameter space is \lesssim 1.5% for unpolarized and
transversally polarized W bosons, and \lesssim 2.7% for longitudinal W bosons.


title:
K_{L,S} \to \pi \pi \nu \bar{\nu} Decays Within and Beyond the Standard
  Model

abstract:
  The decays K_{L,S} -> \pi^o \pi^o \nu \bar{\nu} and K_{L,S} -> \pi^+ \pi^-
\nu \bar{\nu} involve the weak transition from a strange to a non-strange
quark. Although they have considerably smaller branching ratios than those for
the corresponding rare processes involving single pions, some may be more
distinguishable experimentally from background processes and thus could provide
another probe of the s -> d \nu \bar{\nu} transition. Using recent knowledge of
the CKM matrix elements and measurements of related processes, we give improved
predictions for their branching ratios both within and beyond the Standard
Model.


title:
Remark on approximation in the calculation of the primordial spectrum
  generated during inflation

abstract:
  We re-examine approximations in the analytical calculation of the primordial
spectrum of cosmological perturbation produced during inflation. Taking two
inflation models (chaotic inflation and natural inflation) as examples, we
numerically verify the accuracy of these approximations.


title:
Is the $\nu_\mu --> \nu_s$ oscillation solution to the atmospheric
  neutrino anomaly excluded by the superKamiokande data?

abstract:
  Recently the SuperKamiokande collaboration have claimed that their data
exclude the $\nu_\mu --> \nu_s$ solution to the atmospheric neutrino anomaly at
more than 99% C.L. We critically examine this claim.


title:
Quantum effects for the neutrino mixing matrix in the democratic-type
  model

abstract:
  We investigate the quantum effects for the democratic-type neutrino mass
matrix given at the right-handed neutrino mass scale $m_R$ in order to see (i)
whether $\theta_{23}=-\pi/4$ predicted by the model is stable to explain the
atmospheric neutrino anomaly, (ii) how $\theta_{12}$ and $\theta_{13}$ behave,
and (iii) whether the predicted Dirac CP phase $\delta$ keeps maximal size, at
the weak scale $m_Z$. We find that, for the (inversely) hierarchical mass
spectrum with $m_1\sim m_2$, $\theta_{23}$ and $\theta_{13}$ are stable, while
$\theta_{12}$ is not so, which leads to the possibility that the solar neutrino
mixing angle can become large at $m_Z$ even if it is taken small at $m_R$. We
also show that $\delta$ keeps almost maximal for the above mass spectrum, and
our model can give the large CP violation effect in the future neutrino
oscillation experiments if the solar neutrino puzzle is explained by the large
mixing angle MSW solution.


title: Properties of a family of n reggeized gluon states in multicolour QCD

abstract:
  A general relation between families of (n+1) gluon and n gluon eigenstates of
the BKP evolution kernels in the multicolour limit of QCD is derived. It allows
to construct an (n+1) gluon eigenstate if an n gluon eigenstate is known; this
solution is Bose symmetric and thus physical for even n. A recently found
family of odderon solutions corresponds to the particular case n=2.


title: Inclusive and Semi-Inclusive Polarized DIS Data Revisited

abstract:
  We perform a combined next to leading order analysis to both inclusive and
semi-inclusive polarized deep inelastic scattering data, assessing the impact
of new data in the extraction of the sea quark and gluon spin dependent
densities. In particular, we find that semi-inclusive data show a clear
preference for a positive 'Delta ubar' distribution, although are almost
insensitive to different alternatives to 'Delta dbar'.


title: Colour Deconfinement in Nuclear Collisions

abstract:
  QCD predicts that strongly interacting matter will undergo a transition from
a state of hadronic constituents to a plasma of unbound quarks and gluons. We
first survey the conceptual features of this transition and its description in
finite temperature lattice QCD, before we address its experimental
investigation through high energy nucleus-nucleus collisions. After considering
the conditions achievable in such collisions, we discuss the possible probes to
check if the produced medium in its early stages was indeed deconfined. We then
elaborate the method that has emerged and the results which were obtained using
the most extensively studied deconfinement probe, the suppression of charmonium
production. In closing, we discuss possible supporting information provided
through the study of soft hadronic probes.


title: Finite pion width effects on the rho--meson

abstract:
  We study the influence of the finite damping width of pions on the in-medium
properties of the rho-meson in an interacting meson gas model at finite
temperature. Using vector dominance also implications on the resulting dilepton
spectra from the decay of the rho-meson are presented. A set of coupled Dyson
equations with self energies up to the sunset diagram level is solved self
consistently. Following a Phi-derivable scheme the self energies are
dynamically determined by the self consistent propagators. Some problems
concerning the self consistent treatment of vector or gauge bosons on the
propagator level, in particular, if coupled to currents arising from particles
with a sizable damping width, are discussed.


title: Neutrino Zero Modes on Electroweak Strings

abstract:
  Zero modes of massive standard model fermions have been found on electroweak
Z-strings. A zero mode solution for a massless left-handed neutrino is also
known, but was thought to be non-normalizable. Here we show that although this
mode is not discretely normalizable, it is delta-function normalizable and the
correct interpretation of this solution is within the framework of the
continuum spectrum. We also analyze an extension of the standard model
including right-handed neutrinos in which neutrinos have Dirac masses, arising
from a Yukawa coupling to the usual SU(2) Higgs doublet, and right-handed
Majorana masses. The Majorana mass terms are taken to be spatially homogeneous
and are presumed to arise from the vacuum expectation value of some field
acquired in a phase transition well above the electroweak phase transition. The
resulting zero energy equations have a discrete zero mode.


title:
Green Functions in Coordinate Space for Gauge Bosons at Finite
  Temperature

abstract:
  The thermal Green function $D^{\mu\nu}(x)$ for free, massless gauge bosons is
computed exactly in a variety of gauges (Feynman, covariant, Coulomb, and
Landshoff-Rebhan). At large temporal separations it falls exponentially. At
large spatial separations it falls like $T/r$. In contrast, the
zero-temperature propagator falls quadratically in both regimes, being
proportional to $1/x^{2}$.


title:
Reach of the CERN LHC for the Minimal Anomaly-Mediated SUSY Breaking
  Model

abstract:
  We examine the reach of the CERN LHC pp collider for supersymmetric models
where the dominant contribution to soft SUSY breaking parameters arises from
the superconformal anomaly. In the simplest viable anomaly mediated SUSY
breaking (AMSB) model, tachyonic slepton squared masses are made positive by
adding a universal contribution m_0^2 to all scalars. We use the event
generator ISAJET to generate AMSB signal events as a function of model
parameter space. Assuming an integrated luminosity of 10 fb-1, the LHC can
reach to values of $m_{\tg}\sim 2.3$ TeV for low values of $m_0$, where the
dilepton plus jets plus E_T(missing) channel offers the best reach. For large
$m_0$, the best signature is typically 0 or 1 isolated lepton plus jets plus
E_T(missing); in this case the reach is typically diminished to values of
$m_{\tg}\sim 1.3$ TeV. The presence of terminating tracks in a subset of signal
events could serve to verify the presence of a long lived lightest chargino
which is generic in the minimal AMSB model.


title: Deconfinement in QCD at Finite Temperature

abstract:
  We present a simple and intuitive picture for the deconfinement of quarks and
gluons at finite temperature: as the temperature increases, QCD behaves like
QED at T=0. We show this by calculating the QCD coupling constant as a function
of the temperature and of the external momenta used to probe quarks and gluons.


title: On the use of the reciprocal basis in neutral meson mixing

abstract:
  In the presence of CP violation, the effective Hamiltonian matrix describing
a neutral meson anti-meson system does not commute with its hermitian
conjugate. As a result, this matrix cannot be diagonalized by a unitary
transformation and one needs to introduce a reciprocal basis. Although known,
this fact is seldom discussed and almost never used. Here, we use this concept
to highlight a parametrization of the Hamiltonian matrix in terms of physical
observables, and we show that using it reduces a number of long and tedious
derivations into simple matrix multiplications. These results have a
straightforward application for propagation in matter. We also comment on the
(mathematical) relation with neutrino oscillations.


title:
Analysis of the Superkamiokande atmospheric neutrino data in the
  framework of four neutrino mixings

abstract:
  Superkamiokande atmospheric neutrino data for 990 days are analyzed in the
framework of four neutrinos without imposing constraints of Big Bang
Nucleosynthesis. It is shown that the wide range of the oscillation parameters
is allowed at 90% confidence level ($0.1\lsim |U_{s1}|^2+|U_{s2}|^2\le 1$).


title: Microscopic Theory of the Standard Model

abstract:
  The operator manifold formalism (part I) enables the unification of the
geometry and the field theory, and yields the quantization of geometry. This is
the mathematical framework for our physical outlook that the geometry and
fields, with the internal symmetries and all interactions, as well the four
major principles of relativity (special and general), quantum, gauge and colour
confinement, are derivative, and come into being simultaneously in the stable
system of the underlying ``primordial structures''. In part II we attempt to
develop, further, the microscopic approach to the Standard Model of particle
physics, which enables an insight to the key problems of particle
phenomenology. We suggest the microscopic theory of the unified electroweak
interactions. The Higgs bosons have arisen on an analogy of the Cooper pairs in
superconductivity. Besides of microscopic interpretation of all physical
parameters the resulting theory also makes plausible following testable
implications for the current experiments: 1. The Higgs bosons never could
emerge in spacetime continuum, thus, they cannot be discovered in these
experiments nor at any energy range. 2. For each of the three SM families of
quarks and leptons there are corresponding heavy family partners with the same
quantum numbers lying far above the electroweak scale, respectively, at the
energy threshold values: $E_{1}>(419.6 \pm 12.0)GeV, \quad E_{2}= (457.6 \pm
13.2)GeV$ and $E_{3}=(521.4 \pm 15.0)GeV.$