title: A simple connection between neutrino oscillation and leptogenesis

abstract:
  The usual see-saw formula is modified by the presence of two Higgs triplets
in left-right symmetric theories. The contribution from the left-handed Higgs
triplet to the see-saw formula can dominate over the conventional one when the
neutrino Dirac mass matrix is identified with the charged lepton or down quark
mass matrix. In this case an analytic calculation of the lepton asymmetry,
generated by the decay of the lightest right-handed Majorana neutrino, is
possible. For typical parameters, the out-of-equilibrium condition for the
decay is automatically fulfilled. The baryon asymmetry has the correct order of
magnitude, as long as the lightest mass eigenstate is not much lighter then
10^{-6} to 10^{-8} eV, depending on the solution of the solar neutrino problem.
A sizable signal in neutrinoless double beta decay can be expected, as long as
the smallest mass eigenstate is not much lighter than 10^{-3} eV and the Dirac
mass matrix is identified with the charged lepton mass matrix.


title: Physical stability of the QED vacuum

abstract:
  The possibility of electron-positron pair creation by an electric field is
studied by using only those methods in field theory the predictions of which
are confirmed experimentally. These methods include the perturbative method of
quantum electrodynamics and the bases of classical electrodynamics. Such an
approach includes the back reaction. It is found that the vacuum is always
stable, in the sense that pair creation, if occurs, cannot be interpreted as a
decay of the vacuum, but rather as a decay of the source of the electric field
or as a process similar to bremsstrahlung. It is also found that there is no
pair creation in a static electric field, because it is inconsistent with
energy conservation. The non-perturbative aspects arising from the Borel
summation of a divergent perturbative expansion are discussed. It is argued
that the conventional methods that predict pair creation in a classical
background electric field cannot serve even as approximations. The analogy with
the possibility of particle creation by a gravitational field is qualitatively
discussed.


title: Models for Geometric CP Violation with Extra Dimensions

abstract:
  In a recent paper, two of us (D.C. and R.N.M.) proposed a new way to break CP
symmetry geometrically using orbifold projections. The mechanism can be
realized in the five dimensional brane bulk picture. In this paper, we
elaborate on this proposal and provide additional examples of models of this
type. We also note the phenomenological implications of some of these models.


title: Higgs bosons in the simplest SUSY models

abstract:
  Nowadays in the MSSM the moderate values of $\tan\beta$ are almost excluded
by LEP II lower bound on the lightest Higgs boson mass. In the Next-to-Minimal
Supersymmetric Standard Model the theoretical upper bound on it increases and
reaches maximal value in the strong Yukawa coupling limit when all solutions of
renormalization group equations are concentrated near the quasi-fixed point.
For calculation of Higgs boson spectrum the perturbation theory method can be
applied. We investigate the particle spectrum in the framework of the modified
NMSSM which leads to the self-consistent solution in the strong Yukawa coupling
limit. This model allows one to get $m_h\sim 125$ GeV at values of
$\tan\beta\ge 1.9$. In the investigated model the lightest Higgs boson mass
does not exceed $130.5\pm 3.5$ GeV. The upper bound on the lightest CP-even
Higgs boson mass in more complicated supersymmetric models is also discussed.


title: Scalar sigma meson effects in rho and omega decays into pi0 pi0 gamma

abstract:
  The complementarity between Chiral Perturbation Theory and the Linear Sigma
Model in the scalar channel is exploited to study $\pi^0\pi^0$ production in
$\rho$ and $\omega$ radiative decays, where the effects of a low mass scalar
resonance $\sigma(500)$ should manifest. The recently reported data on
$\rho\to\pi^0\pi^0\gamma$ seem to require the contribution of a low mass and
moderately narrow $\sigma(500)$. The properties of this controversial state
could be fixed by improving the accuracy of these measurements. Data on
$\omega\to\pi^0\pi^0\gamma$ can also be accommodated in our framework, but are
much less sensitive to the $\sigma(500)$ properties.


title: Supersymmetric dark matter and neutralino-nucleon cross section

abstract:
  We review the direct detection of supersymmetric dark matter in the light of
recent experimental results. In particular, we show that regions in the
parameter space of several supergravity scenarios with a neutralino-nucleon
cross section of order of $10^{-6}$ pb, i.e., where current dark matter
detectors are sensitive, can be obtained. These are scenarios with large $\tan
\beta$, with non-universal soft supersymmetry-breaking terms, with multi-TeV
masses for scalar superpartners known as `focus point' supersymmetry, and
finally scenarios with intermediate unification scale which appear naturally in
some superstring constructions.


title: Conformal Invariance of Unitarity Corrections

abstract:
  We study perturbative unitarity corrections in the generalized leading
logarithmic approximation in high energy QCD. It is shown that the
corresponding amplitudes with up to six gluons in the t-channel are conformally
invariant in impact parameter space. In particular we give a new representation
for the two-to-six reggeized gluon vertex in terms of conformally invariant
functions. With the help of this representation an interesting regularity in
the structure of the two-to-four and the two-to-six transition vertices is
found.


title: Indirect Search for Neutralino Dark Matter with High Energy Neutrinos

abstract:
  We investigate the prospects of indirect searches for supersymmetric
neutralino dark matter. Relic neutralinos gravitationally accumulate in the Sun
and their annihilations produce high energy neutrinos. Muon neutrinos of this
origin can be seen in large detectors like AMANDA, IceCube and ANTARES. We
evaluate the relic density and the detection rate in several models---the
minimal supersymmetric model, minimal supergravity, and supergravity with
non-universal Higgs boson masses at the grand unification scale. We make
realistic estimates for the indirect detection rates including effects of the
muon detection threshold, quark hadronization, and solar absorption. We find
good prospects for detection of neutralinos with mass above 200 GeV.


title: Thermal Gauge Field Theories

abstract:
  The real- and imaginary-time-formalisms of thermal field theory and their
extension to gauge theories is reviewed. Questions of gauge (in-)dependence are
discussed in detail, in particular the possible gauge dependences of the
singularities of dressed propagators from which the quasiparticle spectrum is
obtained. The existing results on next-to-leading order corrections to
non-Abelian screening and dispersion laws of hard-thermal-loop quasiparticles
are surveyed. Finally, the role of the asymptotic thermal masses in
self-consistent approximations to thermodynamic potentials is described and it
is shown how the problem of the apparently poor convergence of thermal
perturbation theory might be overcome.


title: Hadron Production in Neutrino-Nucleon Interactions at High Energies

abstract:
  The multi-particle production at high energy neutrino- nucleon collisions are
investigated through the analysis of the data of the experiment CERN-WA-025 at
neutrino energy less than 260GeV and the experiments FNAL-616 and FNAL-701 at
energy range 120-250 GeV. The general features of these experiments are used as
base to build a hypothetical model that views the reaction by a Feynman diagram
of two vertices. The first of which concerns the weak interaction between the
neutrino and the quark constituents of the nucleon. At the second vertex, a
strong color field is assumed to play the role of particle production, which
depend on the momentum transferred from the first vertex. The wave function of
the nucleon quarks are determined using the variation method and relevant
boundary conditions are applied to calculate the deep inelastic cross sections
of the virtual diagram.


title:
Determination of the strangeness contents of light-flavour isoscalars
  from its production rates in hadronic Z decays measured at LEP

abstract:
  A new phenomenological approach is suggested to determine the strangeness
contents of light-flavour isoscalars. This approach is based on
phenomenological laws of hadron production related to the spin, isospin,
strangeness content and mass of the particles. The ``effective'' numbers of s
and \bar{s} quarks in the isoscalar partners i_1 and i_2 are given by the
nonstrange-strange mixing angle \phi: k(i_1)=2\sin^2\phi and
k(i_2)=2\cos^2\phi. From the total production rates per hadronic Z decay of all
light-flavour hadrons measured so far at LEP the values for k are found to be:
k(\eta) \equiv 2-k(\eta^{\prime}) = 0.91 \pm 0.12, k(\phi) \equiv 2-k(\omega) =
1.94 \pm 0.09, k(f_2^{\prime}) \equiv 2-k(f_2) = 1.84 \pm 0.21 and k(f_0) =
0.09 \pm 0.13. Our results on the \eta--\eta^{\prime}, \omega--\phi and
f_2--f_2^{\prime} isoscalar mixing are consistent with the present experimental
evidence. Quite remarkably, our value for k(\eta) corresponds to the
singlet-octet mixing angle \theta_P = -12.4^{\circ} \pm 3.5^{\circ}. The
obtained strangeness content of the f_0(980) scalar/isoscalar is not consistent
with the values supported by different model studies. However, taking the
f_0(980) in our analysis with the mass of the bare state (K-matrix pole)
f_0^{bare}(720 \pm 100), the mixing angle is found to be: |\phi_S^{bare}| =
73^{\circ} \pm 7^{\circ} \pm 24^{\circ}, in good agreement with the prediction
of the K-matrix analysis.


title: A minimal model with large extra dimensions to fit the neutrino data

abstract:
  The existence of large extra dimensions enables to explain very simply the
various neutrino suppression data. The flavour neutrinos, confined on the
brane, are coupled to a "bulk" neutrino state, which is seen as an infinite
tower of Kaluza-Klein states from the 4-dimensional point of view. The
oscillation of flavour neutrinos into these states can lead to a global and
sizable energy-independent suppression at large distances, which can be related
to the solar neutrino puzzle.


title:
A Possibility to Measure CP-Violating Effects in the Decay K --> mu nu
  gamma

abstract:
  It is argued that a precise measurement of the transverse component of the
muon spin in the decay K --> mu nu gamma makes it possible to obtain more
stringent limits on CP-violating parameters of the leptoquark, SUSY and
left-right symmetric models. The results of the calculations of the CP-even
transverse component of the muon spin in the decay K --> mu nu gamma due to the
final-state electromagnetic interactions are presented. The weighted average of
the transverse component of the muon spin comprises 2.3 times 10^{-4}.


title: Pion light cone wave function in the non-local NJL model

abstract:
  We use the simple instanton motivated NJL-type model to calculate the leading
twist pion light cone wave function. The model consists in employing the
momentum dependent quark mass in the quark loop entering the definition of the
wave function. The result is analytical up to a solution of a certain algebraic
equation. Various properties including the kT dependence of the pion wave
function are discussed. The resulting kT integrated wave function is not
asymptotic and is in agreement with recent analysis of the CLEO data.


title: Parametric amplification versus collisions: An illustrative application

abstract:
  We investigate the time dependence of the quantum statistical model with
$\lambda \phi^4/4!$ self-interaction and consider the resulting induced
particle number density. For a special example in which the classical
approximation exhibits parametric resonance, the effects of the back reaction
and especially of collisions, treated in a perturbative way, are analysed.


title: Leptonic constants of heavy quarkonia in potential approach of NRQCD

abstract:
  We consider a general scheme for calculating the leptonic constant of heavy
quarkonium QQ-bar in the framework of nonrelativistic quantum chromodynamics,
NRQCD, operating as the effective theory of nonrelativistic heavy quarks. We
explore the approach of static potential in QCD, which takes into account both
the evolution of effective charge in the three-loop approximation and the
linearly raising potential term, which provides the quark confinement. The
leptonic constants of bb-bar and cc-bar systems are evaluated by making use of
two-loop anomalous dimension for the current of nonrelativistic quarks, where
the factor for the normalization of matrix element is introduced in order to
preserve the renormalization group invariance of estimates.


title: Large Neutrino Mixing in Grand Unified Theories

abstract:
  A non-minimal, semi-realistic version of supersymmetric SU(5) grand unified
theory is discussed. The solution of the doublet-triplet splitting problem
leads to a better agreement between the predicted and observed values of the
low-energy strong coupling constant and to a prolongation of the proton
lifetime. A U(1) flavor symmetry allows to accommodate a realistic mass
spectrum in the charged and in the neutral fermion sectors and protects
doublet-triplet splitting and proton decay from dangerous radiative corrections
or non-renormalizable operators.


title:
Charged Particle Fluctuation as Signal of the Dynamics in Heavy Ion
  Processes

abstract:
  We compare the dispersion of the charges in a central rapidity box according
to the Dual Parton Model with the predictions of statistical models.
Significant deviations are found in heavy ion collisions at RHIC and LHC
energies. Hence the charged particle fluctuations should provide a clear signal
of the dynamics of heavy ion processes. They should allow to directly measure
the degree of thermalization in a quantitative way.


title: Poincare Invariant Algebra From Instant to Light-Front Quantization

abstract:
  We present the Poincare algebra interpolating between instant and light-front
time quantizations. The angular momentum operators satisfying SU(2) algebra are
constructed in an arbitrary interpolation angle and shown to be identical to
the ordinary angular momentum and Leutwyler-Stern angular momentum in the
instant and light-front quantization limits, respectively. The exchange of the
dynamical role between the transverse angular mometum and the boost operators
is manifest in our newly constructed algebra.


title: New ways to explore factorization in b decays

abstract:
  We propose to study factorization breaking effects in exclusive b decays
where they are strongly enhanced over the factorizing contributions. This can
be done by selecting final-state mesons with a small decay constant or with
spin greater than one. We find a variety of decay modes which could help
understand the dynamical origin of factorization and the mechanisms responsible
for its breaking.


title: Energy Loss versus Shadowing in the Drell-Yan Reaction on Nuclei

abstract:
  We present a new analysis of the E772 and E866 experiments on the nuclear
dependence of Drell-Yan (DY) lepton pair production resulting from the
bombardment of $^2H$, Be, C, Ca, Fe, and W targets by 800 GeV/c protons at
Fermilab. We employ a light-cone formulation of the DY reaction in the rest
frame of the nucleus, where the dimuons detected at small values of Bjorken x_2
<< 1 may be considered to originate from the decay of a heavy photon radiated
from an incident quark in a bremsstrahlung process. We infer the energy loss of
the quark by examining the suppression of the nuclear-dependent DY ratios seen
as a function of projectile momentum fraction x_1 and dimuon mass M. Shadowing,
which also leads to nuclear suppression of dimuons, is calculated within the
same approach employing the results of phenomenological fits to deep inelastic
scattering data from HERA. The analysis yields -dE/dz =2.73 +/- 0.37 +/- 0.5
GeV/fm for the rate of quark energy loss per unit path length, a value
consistent with theoretical expectations including the effects of the inelastic
interaction of the incident proton at the surface of the nucleus. This is the
first observation of a nonzero energy loss effect in such experiments.


title:
Probing Flavor Changing Neutrino Interactions Using Neutrino Beams from
  a Muon Storage Ring

abstract:
  We discuss the capabilities of a future neutrino factory based on intense
neutrino beams from a muon storage ring to explore the non-standard neutrino
matter interactions, which are assumed to be sub-leading effects in the
standard mass induced neutrino oscillations. The conjunction of these two
mechanisms will magnify fake CP violating effect in the presence of matter
which is not coming from the CP phase in the neutrino mixing matrix. We show
that such fake CP violation can be observed in neutrino factory experiments by
measuring the difference between the neutrino and anti-neutrino probabilities.
In order to perform such test, we consider three neutrino flavors, admitting
the mixing parameters in the range consistent with the oscillation solution to
the atmospheric and the solar neutrino problems, as well as with the
constraints imposed by the reactor neutrino data. We show that with a 10 kt
detector with 5 years of operation, a stored muon energy E_\mu \ge 20 GeV, 2
\times 10^{20} muon decays per year, and a baseline L \sim 732 km, such a
neutrino facility can probe the non-standard flavor changing neutrino
interactions down to the level of (10^{-3}-10^{-2})~G_F, in both \nu_\mu \to
\nu_\tau/ \bar \nu_\mu \to \bar \nu_\tau and \nu_e \to \nu_\tau/\bar \nu_e \to
\bar \nu_\tau modes.


title: Is the Sullivan Process Compatible with QCD Chiral Dynamics?

abstract:
  We calculate the leading non-analytic quark-mass dependence in the moments of
isovector quark distributions using heavy-baryon chiral perturbation theory.
The results differ from those obtained from the Sullivan process in which hard
scattering occurs through the virtual pion cloud of the nucleon. Our results
provide useful guidance for improving upon the meson-cloud model and can be
used to constrain the extrapolations of the existing lattice QCD results to the
physical quark masses.


title: $dm/d\mu$ in the Nambu--Jona-Lasinio model

abstract:
  Using the Nambu--Jona-Lasinio (NJL) model we study responses of the pion and
kaon masses to changes in the chemical potential, $dm/d\mu$, at zero and finite
chemical potential. We find that the behavior of $dm/d\mu$ for the pion is
quite different from that for the kaon. Our results can give a clue for future
studies of $dm/d\mu$ on the lattice.


title: Discovery potential of charged Higgs at LHC in H+- ->tau nu decays

abstract:
  The discovery potential of charged Higgs from pp->tH+- in the H+- -> tau nu
decay channel is investigated in CMS and ATLAS. For m_H>m_t, the most relevant
channels are H+- -> tb and H+- -> tau nu. Whereas the former has the largest
branching ratio it suffers of large irreducible backgrounds, while the latter
offers a very clean enviroment when appropriate cuts are used. Making use of
the tau polarization effects, in the purely hadronic final states an almost
background-free signal is selected. The expected discovery range is evaluated
for CMS and ATLAS with 30 fb^-1 each in the low luminosity running conditions
and the combined results are presented.


title: Extended Minimal Flavour Violating MSSM and Implications for B Physics

abstract:
  The recently reported measurements of the CP asymmetry a(psi K) by the BABAR
and BELLE collaborations are in good agreement with the standard model (SM)
prediction, resulting from the unitarity of the CKM matrix. The so-called
minimal flavour violating (MFV) supersymmetric extensions of the standard
model, in which the CKM matrix remains the only flavour changing structure,
predict a(psi K) similar to the one in the SM. With the anticipated precision
in a(psi K) and other CP asymmetries at the B factories and hadron colliders,
one hopes to pin down any possible deviation from the SM. We discuss an
extension of the MFV-supersymmetric models which comfortably accommodates the
current measurements of the CP asymmetry a(psi K), but differs from the SM and
the MFV-supersymmetric models due to an additional flavour changing structure
beyond the CKM matrix. We suggest specific tests in forthcoming experiments in
B physics. In addition to the CP-asymmetries in B-meson decays, such as a(psi
K) and a(pi pi), and the mass difference Delta M_s in the Bs-bar(Bs) system, we
emphasize measurements of the radiative transition b -> d gamma as sensitive
probes of the postulated flavour changing structure. Interestingly, the
CKM-unitarity analysis in the Extended-MFV model also allows solutions rho < 0,
as opposed to the SM and the MFV models for which only rho > 0 solutions are
now admissible, implying gamma > pi/2, where gamma=- arg (Vub). Such large
values of gamma are hinted by the current measurements of the branching ratios
for the decays B -> pi pi and B -> K pi.


title: Strangeness enhancement in heavy ion collisions

abstract:
  We argue that the main features of baryon and anti-baryon enhancement
observed by the WA97 collaboration can be described using canonical formulation
of strangeness conservation. Within this formulation strangeness enhancement
could be larger at lower collision energies.


title:
Density Dependence of Nucleon Bag Constant, Radius and Mass in an
  Effective Field Theory Model of QCD

abstract:
  With the global color symmetry model (GCM) being extended to finite chemical
potential, the density dependence of the bag constant, the total energy and the
radius of a nucleon, as well as the quark condensate in nuclear matter are
investigated. A maximal nuclear matter density for the existence of the bag
with three quarks confined within is obtained. The calculated results indicate
that, before the maximal density is reached, the bag constant, the total energy
of a nucleon and the quark condensate decrease gradually, and the radius of a
nucleon increases, with the increasing of the nuclear matter density.
Nevertheless no sudden change emerges. As the maximal nuclear matter density is
reached, a phase transition from nucleons to quarks takes place and the chiral
symmetry is restored.


title:
High-energy neutrinos and hard $\gamma$-rays in coincidence with Gamma
  Ray Bursts

abstract:
  The observations suggest that $\gamma$-ray bursts (GRBs) are produced by jets
of relativistic cannonballs (CBs), emitted in supernova (SN) explosions. The
CBs, reheated by their collision with the SN shell, emit radiation and
Doppler-boost it to the few-hundred keV energy of the GRB's photons.
Chaperoning the GRB, there should be an intense flux of neutrinos of a few
hundreds of GeV energy, made in $\pi^\pm$ decays: the SN shell acts as a dump
of the beam of CBs. The $\nu$ beam carries almost all of the emitted energy,
but is much narrower than the GRB beam and should only be detected in
coincidence with the small fraction of GRBs whose CBs are very precisely
pointing to us. The $\pi^0$s made in the transparent outskirts of the SN shell
decay into energetic $\gamma$-rays (EGRs) of energy of ${\cal{O}}$(100) GeV.
The EGR beam, whose energy fluence is comparable to that of the companion GRB,
is as wide as the GRB beam and should be observable, in coincidence with GRBs,
with existing or planned detectors.


title: Effects of Neutrino Oscillation on the Supernova Neutrino Spectrum

abstract:
  The effects of three-flavor neutrino oscillation on the supernova neutrino
spectrum are studied. We calculate the expected event rate and energy spectra,
and their time evolution at the Superkamiokande (SK) and the Sudbury Neutrino
Observatory (SNO), by using a realistic neutrino burst model based on numerical
simulations of supernova explosions. We also employ a realistic density profile
based on a presupernova model for the calculation of neutrino conversion
probability in supernova envelopes. These realistic models and numerical
calculations allow us to quantitatively estimate the effects of neutrino
oscillation in a more realistic way than previous studies. We then found that
the degeneracy of the solutions of the solar neutrino problem can be broken by
the combination of the SK and SNO detections of a future Galactic supernova.


title: Saturation at low $x$

abstract:
  This talk is an attempt to review all our knowledge on saturation at low $x$
both theoretical and experimental, to stimulate a search for saturation effects
at THERA. The main goals of this presentation are 1. To discuss an intuitive
picture of the deep inelastic scattering that leads to the saturation of the
parton densities;
  2. To show that the saturation hypothesis has solid theoretical proof;
  3. To report on the theoretical progress that has been made over the past two
years in high parton density QCD, and on the property of the saturation phase
that emerges from the theory that has been developed;
  4. To collect all that we know theoretically and experimentally about the
saturation scale $Q_s(x)$ .


title: Weak Radiative Decays of Hyperons: Quark Model and Nonlocality

abstract:
  It is proved that symmetry structure of the parity-viol. (p.v.) amplitudes of
weak radiative hyperon decays in the VMD approach, and the violation of Hara's
theorem in particular, are also obtained when direct coupling e_q
\bar{q}\gamma_{\mu}q A^{\mu} of photon to quarks is used in place of VMD. Thus,
violation of Hara's theorem in VMD-based models does not result from the lack
of gauge invariance. It is further shown that, in the static limit of the quark
model, the CA commutator term in the p.v. amplitudes of nonleptonic hyperon
decays (NLHD) and the parity-violating \Sigma ^+ \to p \gamma decay amplitude
are proportional to each other. As a result, Hara's theorem may be satisfied in
this limit if and only if the contribution from the CA commutator in NLHD is
zero. Violation of Hara's theorem is traced back to the nonlocality of quark
model states in the static limit. It is argued that the ensuing intrinsic
baryon nonlocality does not have to be unphysical. It is stressed that the \Xi
^0 \to \Lambda \gamma asymmetry will provide very important information
concerning the presence or absence of nonlocal features in p.v. photon coupling
to baryons at vanishing photon momentum. If the \Xi ^0 \to \Lambda \gamma
asymmetry is found negative, Hara's theorem is satisfied but the
gauge-invariant quark model machinery predicting its violation must miss some
contribution, or be modified. If experiment confirms positive \Xi ^0 \to
\Lambda \gamma asymmetry, then, most likely, Hara's theorem is violated.
Although positive \Xi ^0 \to \Lambda \gamma asymmetry admits of the possibility
that Hara's theorem is satisfied, this alternative is in disagreement with
hints suggested by the similarity of photon and vector-meson couplings and the
observed size of p.v. nuclear forces.


title: Tests of goodness of fit to multiple data sets

abstract:
  We propose a new and rather stringent criterion for testing the goodness of
fit between a theory and experiment. It is motivated by the paradox that the
criterion on \chi^2 for testing a theory is much weaker than the criterion for
finding the best fit value of a parameter in the theory. We present a method by
which the stronger parameter-fitting criterion can be applied to subsets of
data in a global fit.


title:
Two-photon correlations as a sign of sharp transition in quark-gluon
  plasma

abstract:
  The photon production arising due to time variation of the medium has been
considered. The Hamilton formalism for photons in time-variable medium (plasma)
has been developed with application to inclusive photon production. The results
have been used for calculation of the photon production in the course of
transition from quark-gluon phase to hadronic phase in relativistic heavy ion
collisions. The relative strength of the effect as well as specific two- photon
correlations have been evaluated. It has been demonstrated that the opposite
side two-photon correlations are indicative of the sharp transition from the
quark-gluon phase to hadrons.


title: The First Three Pomerons

abstract:
  A model of a three Pomeron contribution to high energy elastic $pp$ and $\bar
p p$ scattering is proposed. The data are well described for all momenta
($0.01\le |t|\le 14. GeV^2$) and energies ($8.\le\sqrt{s}\le 1800. GeV$)
($\chi^2/{\rm d.o.f.}=2.74$). The model predicts the appearance of two dips in
the differential cross-section which will be measured at LHC. The parameters of
the Pomeron trajectories are: $\alpha(0)_{{\Bbb P}_1}=1.058, \alpha'(0)_{{\Bbb
P}_1}=0.560 (GeV^{-2});$ $\alpha(0)_{{\Bbb P}_2}=1.167, \alpha'(0)_{{\Bbb
P}_2}=0.273 (GeV^{-2});$ $\alpha(0)_{{\Bbb P}_3}=1.203, \alpha'(0)_{{\Bbb
P}_3}=0.094 (GeV^{-2}).$


title: Electroproduction of psi' and polarized gluon distribution in a proton

abstract:
  In order to get information about the polarized gluon distribution in a
proton, we studied the electroproduction of \psi' in polarized electron and
polarized proton collisions in the framework of the NRQCD factorization
approach. The value of the cross section d\Delta\sigma / dp_T^2 for color-octet
mechanism is about 5 times larger than that for color-singlet one, and it might
be another test of the color-octet model if the polarized gluon distribution
\Delta g(x) is well known. Furthermore, we found that this reaction is quite
effective for testing the model of gluon polarization by measuring the double
spin asymmetry A_{LL} for the initial electron and proton. Though the shape of
p_T^2 distribution of A_{LL} is quite similar for the production mechanism with
color-octet and color-singlet, we can see a big difference in A_{LL} among
various models of the polarized gluon distribution function \Delta g(x).


title: Insights on neutrino lensing

abstract:
  We discuss the gravitational lensing of neutrinos by astrophysical objects.
Unlike photons, neutrinos can cross a stellar core; as a result, the lens
quality improves. We also estimate the depletion of the neutrino flux after
crossing a massive object and the signal amplification expected. While Uranians
alone would benefit from this effect in the Sun, similar effects could be
considered for binary systems.


title: Softly broken lepton numbers and maximal neutrino mixing

abstract:
  We consider lepton mixing in an extension of the Standard Model with three
right-handed neutrino singlets. We require that the three lepton numbers L_e,
L_\mu, and L_\tau be separately conserved in the Yukawa couplings, and we
assume that they are softly broken only by the Majorana mass matrix M_R of the
neutrino singlets. In this framework, where lepton-number breaking occurs at a
scale much higher than the electroweak scale, deviations from
family-lepton-number conservation are calculable and finite, and lepton mixing
stems exclusively from M_R. We then show that a discrete symmetry exists such
that, in the lepton mixing matrix U, maximal atmospheric neutrino mixing
together with U_{e3}=0 can be obtained naturally. Alternatively, if one assumes
that there are two different scales in M_R and that the lepton number \bar L =
L_e - L_\mu - L_\tau is conserved in between them, then maximal solar neutrino
mixing follows naturally. If both the discrete symmetry and intermediate \bar L
conservation are introduced, bimaximal mixing is achieved.


title: Yet another way to measure $\gamma$

abstract:
  We show that the CKM phase $2 \beta+\gamma$ can be extracted from measurement
of the time dependent rates in the decays $\bar{B}^0 \to D^{(*)\pm} M^\mp$ and
$B^0 \to D^{(*)\pm} M^\mp$, where $M=a_0$, $\pi(1300)$, $b_1$, $a_2$, $\pi_2$,
$\rho_3$. These channels have a large asymmetry between decays of $\bar{B}^0$
and $B^0$ into the same final state. Even though the branching ratios are
small, their sensitivity to $\gamma$ can be competitive with decays into
$D^{(*)}$ and $(\pi,\rho,a_1)$.


title: Mass Expansions of Screened Perturbation Theory

abstract:
  The thermodynamics of massless phi^4-theory is studied within screened
perturbation theory (SPT). In this method the perturbative expansion is
reorganized by adding and subtracting a mass term in the Lagrangian. We
analytically calculate the pressure and entropy to three-loop order and the
screening mass to two-loop order, expanding in powers of m/T. The truncated
m/T-expansion results are compared with numerical SPT results for the pressure,
entropy and screening mass which are accurate to all orders in m/T. It is shown
that the m/T-expansion converges quickly and provides an accurate description
of the thermodynamic functions for large values of the coupling constant.


title: The width difference of B_s mesons

abstract:
  Next-to-leading order QCD corrections to the width difference Delta Gamma in
the B_s-meson system are presented. I further discuss how Delta Gamma can be
used to detect new physics.


title:
Hybrid Quintessence with an End or Quintessence from Branes and Large
  Dimensions

abstract:
  We describe a model of hybrid quintessence in which in addition to the
tracker field there is a trigger field which is responsible for ending
quintessence. As a result, hybrid quintessence does not suffer from the
problems associated with the eternal acceleration of the universe. We derive
the hybrid quintessence potential on branes from the interbrane interaction in
string theory and show that it requires TeV scale strings and two millimeter
size dimensions. This scenario predicts a dark energy density of $O(mm^{-4})$
and relates the smallness of this energy to the large size of the extra
dimensions.


title:
Improved Determination of |V_{ub}| from Inclusive Semileptonic B-Meson
  Decays

abstract:
  We reduce the perturbative uncertainty in the determination of |V_{ub}| from
inclusive semileptonic B decays by calculating the rate of B -> X_u l nu events
with dilepton invariant mass q^2>(M_B-M_D)^2 at subleading order in the hybrid
expansion, and to next-to-leading order in renormalization-group improved
perturbation theory. We also resum logarithmic corrections to the leading
power-suppressed contributions. Studying the effect of different b-quark mass
definitions we find that the branching ratio after the cut is Br(B -> X_u l
nu)=(20.9+-4.0)|V_{ub}|^2, where the dominant error is due to the uncertainty
in the b-quark mass. This implies that |V_{ub}| can be determined with a
precision of about 10%.


title: The Counting of Generalized Polarizabilities

abstract:
  We demonstrate a concise method to enumerate the number of generalized
polarizabilities---quantities characterizing the independent observables in
singly-virtual Compton scattering---for a target particle of arbitrary spin s.
By using crossing symmetry and J^{PC} conservation, we show that this number is
(10s+1+delta_{s,0}).


title: Slavnov-Taylor identity for nonequilibrium quark-gluon plasma

abstract:
  Within the closed-time-path formalism of nonequilibrium QCD, we derive a
Slavnov-Taylor (ST) identity for the gluon polarization tensor. The ST identity
takes the same form both in Coulomb and covariant gauges. Application to
quasi-uniform quark-gluon plasma (QGP) near equilibrium or nonequilibrium
quasistationary QGP is made.


title: Dynamical Doublet-Triplet Higgs Mass Splitting

abstract:
  We propose a new mechanism towards the solution to the doublet-triplet Higgs
mass splitting problem in the supersymmetric grand unified theory. Our model is
based on the gauge group $SU(5)_H \times SU(5)_{GUT}$, where $SU(5)_H$ and
$SU(5)_{GUT}$ are a new strong gauge interaction and the ordinary grand unified
gauge group, respectively. The doublet-triplet Higgs mass splitting is realized
through the quantum deformation of moduli space caused by the strong $SU(5)_H$
gauge dynamics. The low energy description of our model is given by the minimal
supersymmetric standard model.


title:
Preliminaries on a Lattice Analysis of The Pion Light-cone Wave
  function: a Partonic Signal?

abstract:
  We present the first attempt of a new method to compute the pion light-cone
wave function (LCWF) on the lattice. We compute the matrix element between the
pion and the vacuum of a non-local operator: the propagator of a ``scalar
quark'' (named for short "squark"). A theoretical analysis shows that for some
kinematical conditions (energetic pion and hard squark) this matrix element
depends dominantly on the LCWF $\Phi_\pi(u), u\in [0,1]$. On the lattice, the
discretization of the parton momenta imposes further constraints on the pion
momentum. The two-point Green functions made of squark-quark and squark-squark
fields show hadron-like bound-state behaviour and verify the standard energy
spectrum. We show some indications that during a short time, after being
created, the system of the spectator quark and the squark behave like partons,
before they form a hadron-like bound state. This short time is the place where
the partonic wave function has to be looked for.


title: QCD Duality and the Mass of the Charm Quark

abstract:
  The mass of the charm quark is analyzed in the context of QCD finite energy
sum rules using recent BESII e+e- annihilation data and a large momentum
expansion of the QCD correlator which incorporates terms to order (alpha_s)^2
(m_c^2/q^2)^6. Using various versions of duality, we obtain the consistent
result m_c(m_c)=(1.37 +- 0.09)GeV. Our result is quite independent of the ones
based on the inverse moment analysis.


title: A light sterile neutrino based on the seesaw mechanism

abstract:
  We propose a simple model of the neutrino mass matrix which can explain the
solar and atmospheric neutrino problems in a 3($\nu_L + \nu_R$) framework.
Assuming that only two right-handed neutrinos are heavy and a Dirac mass matrix
has a special texture, we construct a model with four light neutrinos. The
favorable structure of flavor mixings and mass eigenvalues required by those
neutrino deficits is realized as a result of the seesaw mechanism. Bi-maximal
mixing structure might be obtainable in this scheme. Since it contains a light
sterile neutrino, it has a chance to explain the LSND result successfully. We
consider an embedding of this scenario for the neutrino mass matrix into the
SU(5) grand unification scheme using the Froggatt-Nielsen mechanism based on
$U(1)_{F_1} \times U(1)_{F_2}$. Both a small mixing angle MSW solution and a
large mixing angle MSW solution are obtained for the solar neutrino problem
depending on the charged lepton mass matrix.


title: Rapidity Gap Higgs Signal at the Tevatron and the LHC

abstract:
  We quantify the rate and the signal-to-background ratio for Higgs --> b
anti-b detection in double-diffractive events at the Tevatron and the LHC. The
signal is predicted to be very small at the Tevatron, but observable at the
LHC. We show that the double-diffractive dijet production may serve as a unique
gluon factory. This process can be used also as a Pomeron-Pomeron luminosity
monitor.


title:
Chiral symmetry restoration and the linear form of baryonic Regge
  trajectories

abstract:
  It has recently been suggested that the observed structure of parity
doublets, seen in the spectrum of highly excited baryons, may be due to the
effective restoration of chiral symmetry for these states. This chiral symmetry
restoration high in the spectrum is consistent with the concept of quark-hadron
duality. Moreover, if QCD dynamics implies the linear Regge trajectories for
highly excited baryons, then the MacDowell symmetry requires the parity
doubling to appear, which shows that linear Regge trajectories and chiral
symmetry restoration are well compatible. On the contrary, in the low-energy
part of baryon spectrum the parity doublets are absent because of spontaneous
chiral symmetry breaking. Then the MacDowell symmetry implies that there should
be no linear parallel Regge trajectories. Experimental data shows that this is
indeed the case.


title: W/Z + b,bbar/jets at NLO using the Monte Carlo MCFM

abstract:
  We summarize recent progress in next-to-leading order QCD calculations made
using the Monte Carlo MCFM. In particular, we focus on the calculations of p
anti-p -> W b-bbar, Z b-bbar and highlight the significant corrections to
background estimates for Higgs searches in the channels WH and ZH at the
Tevatron. We also report on the current progress of, and strategies for, the
calculation of the process p anti-p -> W/Z + 2 jets.


title:
Spectral moments of two-point correlators in perturbation theory and
  beyond

abstract:
  We discuss the choice of weight functions for the moments of the spectral
density for two-point correlators of hadronic currents over a finite energy
interval. Of phenomenological relevance is an analysis of the spectra of tau
lepton decay on the energy interval [0,M_tau] and the low-energy hadron
production in e+ e- annihilation. General arguments are given for the
calculability of such moments in perturbation theory using both a finite-order
analysis and infinite resummation on the contour. Nonperturbative contributions
emerging from the operator product expansion for two-point correlators are
discussed within explicit models for the physical spectra. The quantitative
analysis strongly disfavours weight functions that suppress the high-energy
contribution to theoretical moments. This is in agreement with expectations
from qualitative considerations in perturbative QCD with asymptotic freedom. We
discuss the implication of our results for the ultimate accuracy that can be
reached in tau decays and low-energy e+ e- annihilation into hadrons with
present experimental data.


title:
Large mass splittings between charged and neutral Higgs bosons in the
  MSSM

abstract:
  We show that large ($> 100$ GeV) mass splittings between the charged Higgs
boson ($H^\pm$) and the neutral Higgs bosons ($H^0$ and $A^0$) are possible in
the Minimal Supersymmetric Standard Model (MSSM). Such splittings occur when
the $\mu$ parameter is considerably larger than the common SUSY scale,
$M_{SUSY}$, and have significant consequences for MSSM Higgs searches at future
colliders.


title: Hadron production in Au-Au collisions at RHIC

abstract:
  We present an analysis of particle production yields measured in central
Au-Au collisions at RHIC in the framework of the statistical thermal model. We
demonstrate that the model extrapolated from previous analyses at SPS and AGS
energy is in good agreement with the available experimental data at $\sqrt
s=130$ GeV implying a high degree of chemical equilibration. Performing a
$\chi^2$ fit to the data, the range of thermal parameters at chemical freezeout
is determined. At present, the best agreement of the model and the data is
obtained with the baryon chemical potential $\mu_B\simeq 46\pm 5$ MeV and
temperature $T\simeq 174\pm 7$ MeV. More ratios, such as multistrange baryon to
meson, would be required to further constrain the chemical freezeout
conditions. Extrapolating thermal parameters to higher energy, the predictions
of the model for particle production in Au-Au reactions at $\sqrt s=200$ GeV
are also given.


title: W Mass and W+W- Final State Interactions

abstract:
  Precise measurements of the mass and width of the
  W boson are carried out in e+e- collisions at LEP, by kinematic
reconstruction of the invariant mass distributions of WW->qqlv and
  WW->qqqq candidate events. The most recent combination of such results from
ALEPH, DELPHI, L3 and OPAL uses approximately 82% of the final LEP2 integrated
luminosity and is preliminary. The mass of the W boson so determined is
Mw=80.446 +-0.026+-0.030 GeV, while the corresponding direct measurement of the
W boson width gives
  Gamma_W= 2.148+-0.071+-0.063 GeV. These measurements are subject to sizeable
systematic uncertainties from the QCD phenomena of
  Bose-Einstein correlations and colour reconnection. Recent substantial
progress in both of these areas is reported


title: x_F-dependence of J/Psi suppression in pA collisions

abstract:
  Coherence effects are important in the description of collisions with
extended objects as nuclei. At fixed target energies and small x_F, the
coherence length of the fluctuation containing the $c\bar c$ is small and the
usual nuclear absorption model is valid. However, at higher energies and/or x_F
the nucleus is seen as a whole by the fluctuation. In this case, the total, not
the absorptive, $c\bar c-N$ cross section controls the suppression and also
shadowing of gluons appears. We propose that the growth of the coherence length
can explain the x_F-dependence of present experimental data. For this, we need
a ratio of absorptive over total $c\bar c-N$ cross section of 0.2.


title: On a three-body confinement force in hadron spectroscopy

abstract:
  Recently it has been argued that a three-body colour confinement interaction
can affect the stability condition of a three-quark system and the spectrum of
a tetraquark described by any constituent quark model. Here we discuss the role
of a three-body colour confinement interaction in a simple quark model and
present some of its implications for the spectra of baryons, tetraquarks and
six-quark systems.


title:
Particle candidates for dark matter: a case for (dominant or
  subdominant) relic neutralinos

abstract:
  After a short introduction on particle candidates for dark matter within
possible extensions of the standard model, we concentrate on Weakly Interacting
Massive Particles, and on one of their most interesting physical realizations:
the neutralino. We analyze how detectability of relic neutralinos by direct and
indirect means is related to their local and cosmological densities; we use
simple general arguments to discusss different scenarios where relic
neutralinos make up the dominant bulk of dark matter or only a small fraction
of it. Our general arguments are further corroborated by specific numerical
results. We show to which extent the present experiments of direct searches for
WIMPs, when interpreted in terms of relic neutralinos, probe interesting
regions of the supersymmetric parameter space. Our analysis is performed in a
number of different supersymmetric schemes.


title: String Breaking and Quarkonium Dissociation at Finite Temperatures

abstract:
  Recent lattice studies of string breaking in QCD with dynamical quarks
determine the in-medium temperature dependence of the heavy quark potential.
Comparing this to the binding energies of different quarkonium states, we check
if these can decay into open charm/beauty in a confined hadronic medium. Our
studies indicate in particular that the chi_c and the psi dissociate into open
charm below the deconfinement point.


title: Inflaton Condensate Fragmentation in Hybrid Inflation Models

abstract:
  Inflation ends with the formation of a Bose condensate of inflatons. We show
that in hybrid inflation models this condensate is typically unstable with
respect to spatial perturbations and can fragment to condensate lumps. The case
of D-term inflation is considered as an example and it is shown that
fragmentation occurs if \lambda > 0.2g, where \lambda is the superpotential
coupling and g is the U(1)_{FI} gauge coupling. Condensate fragmentation can
result in an effective enhancement of inflaton annihilations over decays as the
main mode of reheating. In the case of D-term inflation models in which the
Standard Model fields carry U(1)_{FI} charges, if condensate fragmentation
occurs then reheating is dominated by inflaton annihilations, typically
resulting in the overproduction of thermal gravitinos. Fragmentation may also
have important consequences for SUSY flat direction dynamics and for
preheating.


title: Dynamics of coupled bosonic systems with applications to preheating

abstract:
  Coupled, multi-field models of inflation can provide several attractive
features unavailable in the case of a single inflaton field. These models have
a rich dynamical structure resulting from the interaction of the fields and
their associated fluctuations. We present a formalism to study the
nonequilibrium dynamics of coupled scalar fields. This formalism solves the
problem of renormalizing interacting models in a transparent way using
dimensional regularization. The evolution is generated by a renormalized
effective Lagrangian which incorporates the dynamics of the mean fields and
their associated fluctuations at one-loop order. We apply our method to two
problems of physical interest: (i) a simple two-field model which exemplifies
applications to reheating in inflation, and (ii) a supersymmetric hybrid
inflation model. This second case is interesting because inflation terminates
via a smooth phase transition which gives rise to a spinodal instability in one
of the fields. We study the evolution of the zero mode of the fields and the
energy density transfer to the fluctuations from the mean fields. We conclude
that back reaction effects can be significant over a wide parameter range. In
particular for the supersymmetric hybrid model we find that particle production
can be suppressed due to these effects.


title: Family Unification, Exotic States and Magnetic Monopoles

abstract:
  The embedding in SU(4)xSU(3)xSU(3) of the well studied gauge groups
SU(4)xSU(2)xSU(2) and SU(3)xSU(3)xSU(3) naturally leads to family unification
as opposed to simple family replication. An inescapable consequence is the
predicted existence of (exotic)color singlet states that carry fractional
electric charge. The corresponding magnetic monopoles carry multiple Dirac
magnetic charge, can be relatively light (\sim 10^{7}-10^{13}GeV), and may be
present in the galaxy not far below the Parker bound.


title: Probing Anomalous Quartic Couplings in e-gamma and gamma-gamma Colliders

abstract:
  We analyze the potential of the e+e- Linear Colliders, operating in the
e-gamma and gamma-gamma modes, to probe anomalous quartic vector--boson
interactions through the multiple production of W's and Z's. We examine all
$SU(2)_L \otimes U(1)_Y$ chiral operators of order p^4 that lead to new
four--gauge--boson interactions but do not alter trilinear vertices. We show
that the e-gamma and gamma-gamma modes are able not only to establish the
existence of a strongly interacting symmetry breaking sector but also to probe
for anomalous quartic couplings of the order of 10^{-2} at 90% CL. Moreover,
the information gathered in the e-gamma mode can be used to reduced the
ambiguities of the e+e- mode.


title: Electroweak symmetry breaking from dimensional deconstruction

abstract:
  We propose a new class of four-dimensional theories for natural electroweak
symmetry breaking, relying neither on supersymmetry nor on strong dynamics at
the TeV scale. The new TeV physics is perturbative, and radiative corrections
to the Higgs mass are finite. The softening of this mass occurs because the
Higgs is an extended object in theory space, resulting in an accidental
symmetry. A novel Higgs potential emerges naturally, requiring a second light
SU(2) doublet scalar.


title: Quarkonium Spectroscopy and Perturbative QCD: A New Perspective

abstract:
  We report new aspects of the recent theoretical progress in heavy quarkonium
physics. (1) Contrary to wide beliefs, the gross structure of the bottomonium
spectrum is described well by the non-relativistic boundstate theory based on
perturbative QCD. (2) This leads to a new physical picture of the bottomonium
states: the boundstate mass is composed mainly of the self-energies of b and
bbar accumulated inside the boundstate. (3) A connection to the conventional
phenomenological potential-model approaches is provided.


title: Remarks on the Electron Structure Function

abstract:
  The electron and photon structure functions are compared. Advantages of the
electron structure function are demonstrated. At very high momenta
probabilistic (partonic) interpretation can be preserved despite strong
$\gamma$-$Z$ interference. At present energies analyses of both the electron
and the photon structure functions give an important test of the experimentally
applied methods. Predictions for the electron structure function at present and
future momenta are given.


title: On the Quasiparticle Description of Lattice QCD Thermodynamics

abstract:
  We propose a novel quasiparticle interpretation of the equation of state of
deconfined QCD at finite temperature. Using appropriate thermal masses, we
introduce a phenomenological parametrization of the onset of confinement in the
vicinity of the predicted phase transition. Lattice results of the energy
density, the pressure and the interaction measure of pure SU(3) gauge theory
are excellently reproduced. We find a relationship between the thermal energy
density of the Yang-Mills vacuum and the chromomagnetic condensate <B^2>_T.
Finally, an extension to QCD with dynamical quarks is discussed. Good agreement
with lattice data for 2, 2+1 and 3 flavour QCD is obtained. We also present the
QCD equation of state for realistic quark masses.


title: Model for dilepton rates from a fireball

abstract:
  We calculate the dilepton emission rate from a fireball created in an
ultra-relativistic heavy-ion collision. For the partonic phase, we complement
the perturbative results by a phenomenological approach based on lattice QCD
results, whereas in the hadronic phase temperature and finite baryon density
effects on the spectral function are considered. The resulting rates are
compared to data from CERES/NA45.


title:
Probing the medium-induced energy loss of bottom quarks by dimuon
  production in heavy ion collisions at LHC

abstract:
  The potential of coming experiments on Large Hadron Collider (LHC) to observe
the rescattering and energy loss of heavy quarks in the dense matter created in
heavy ion collisions is discussed. We analyze the sensitivity of high-mass
mu+mu- pairs from BBbar semileptonic decays and secondary J/Psi from single B
decays to the medium-induced bottom quark energy loss.


title: Very High Multiplicity Hadron Processes

abstract:
  The paper contains a description of a first attempt to understand the
extremely inelastic high energy hadron collisions, when the multiplicity of
produced hadrons considerably exceeds its mean value. Problems with existing
model predictions are discussed. The real-time finite-temperature $S$-matrix
theory is built to have a possibility to find model-free predictions. This
allows to include the statistical effects into consideration and build the
phenomenology. The questions to experiment are formulated at the very end of
the paper.


title: Semi-inclusive B Decays and Direct CP Violation in QCD Factorization

abstract:
  We have systematically investigated the semi-inclusive B decays B->MX, which
are manifestations of the quark decay b->Mq, within the framework of
QCD-improved factorization. These decays are theoretically clean and have
distinctive experimental signatures. We focus on a class of these that do not
require any form factor information and therefore may be especially suitable
for extracting information on the angles $\alpha$ and $\gamma$ of the unitarity
triangle. The nonfactorizable effects, such as vertex-type and penguin-type
corrections to the two-body b decay and hard spectator corrections to the
3-body decay are calculable in the heavy quark limit. QCD factorization is
applicable when the emitted meson is a light meson or a charmonium. We discuss
the issue of the CPT constraint on partial rate asymmetries. The strong phase
coming from final-state rescattering due to hard gluon exchange between the
final states can induce large rate asymmetries for tree-dominated
color-suppressed modes $(\pi^0,\rho^0,\omega)X_{\bar s}$. The nonfactorizable
hard spectator interactions in the 3-body decay, though phase-space suppressed,
are extremely important for the tree-dominated modes
$(\pi^0,\rho^0,\omega)X_{\bar s}, \phi X$, $J X_s,J X$ and the
penguin-dominated mode $\omega X_{s\bar s}$. In fact, they are dominated by the
hard spectator corrections. Our result for ${\cal B} (B\to J/\psi X_s)$ is in
agreement with experiment. The semi-inclusive decay modes: $B^0_s\to
(\pi^0,\rho^0,\omega)X_{\bar s}$, $\rho^0X_{s\bar s}$, $B^0\to(K^-X,K^{*-}X)$
and $B^-\to (K^0X_s,K^{*0}X_s)$ are the most promising ones in searching for
direct CP violation. In fact, they have branching ratios of order
$10^{-6}-10^{-4}$ and CP rate asymmetries of order $(10-40)%$.


title: Uraltsev Sum Rule in Bakamjian-Thomas Quark Models

abstract:
  We show that the sum rule recently proved by Uraltsev in the heavy quark
limit of QCD holds in relativistic quark models \`a la Bakamjian and Thomas,
that were already shown to satisfy Isgur-Wise scaling and Bjorken sum rule.
This new sum rule provides a {\it rationale} for the lower bound of the slope
of the elastic IW function $\rho^2 \geq {3 \over 4}$ obtained within the BT
formalism some years ago. Uraltsev sum rule suggests an inequality
$|\tau_{3/2}(1)| > |\tau_{1/2}(1)|$. This difference is interpreted in the BT
formalism as due to the Wigner rotation of the light quark spin, independently
of a possible LS force. In BT models, the sum rule convergence is very fast,
the $n = 0$ state giving the essential contribution in most of the
phenomenological potential models. We underline that there is a serious
problem, in the heavy quark limit of QCD, between theory and experiment for the
decays $B \to D^*_{0,1}(broad) \ell \nu$, independently of any model
calculation.


title: New Progress in Time-Like Exclusive Processes

abstract:
  We discuss a necessary nonvalence contribution in timelike exclusive
processes. Following a Schwinger-Dyson type of approach, we relate the
nonvalence contribution to an ordinary light-front wave function that has been
extensively tested in the spacelike exclusive processes. A complicate
multi-body energy denominator is exactly cancelled in summing the light-front
time-ordered amplitudes. Applying our method to $K_{\ell3}$ and $D^0\to K^-
\ell^+ \nu_l$ where a rather substantial nonvalence contribution is expected,
we find not only an improvement in comparing with the experimental data but
also a covariance(i.e. frame-indepndence) of existing light-front constituent
quark model.


title: Muon anomalous magnetic moment and supersymmetric dark matter

abstract:
  The anomalous magnetic moment of the muon has recently been measured to be in
conflict with the Standard Model prediction with an excess of 2.6 sigma. Taking
this result as a measurement of the supersymmetric contribution, we find that
at 95% confidence level it imposes an upper bound of about 500 GeV on the
neutralino mass and forbids higgsino dark matter. More interestingly, it
predicts an accessible lower bound on the direct detection rate, and it
strongly favors models detectable by neutrino telescopes. Cosmic ray
antideuterons may also be an interesting probe of such models.


title:
Constraints on extra dimensions from cosmological and terrestrial
  measurements

abstract:
  If quantum fields exist in extra compact dimensions, they will give rise to a
quantum vacuum or Casimir energy. That vacuum energy will manifest itself as a
cosmological constant. The fact that supernova and cosmic microwave background
data indicate that the cosmological constant is of the same order as the
critical mass density to close the universe supplies a lower bound on the size
of the extra dimensions. Recent laboratory constraints on deviations from
Newton's law place an upper limit. The allowed region is so small as to suggest
that either extra compact dimensions do not exist, or their properties are
about to be tightly constrained by experimental data.


title: Quintessence, Cosmological Horizons, and Self-Tuning

abstract:
  We point out that quintessence with an exponential potential V_0 exp(- beta
phi / 3^{1/2} M_p) can account for the present observed acceleration of the
universe, without necessarily leading to eternal acceleration. This occurs for
2.4 < beta < 2.8. Thus a cosmological horizon, which is supposed to be
problematic within the context of string theory, can be avoided. We argue that
this class of models is not particularly fine-tuned. We further examine this
question in the context of a modified Friedmann equation, H^2 ~ rho + p, which
is suggested by higher dimensional self-tuning approaches to the cosmological
constant problem. It is shown that the self-tuning case can also be consistent
with observations, if 1.8 < beta < 2.4. Future observations of high-z
supernovae will be able to test whether beta lies in the desired range.


title:
CP Violation and the Absence of Second Class Currents in Charmless B
  Decays

abstract:
  The absence of second class currents together with the assumption of
factorization for non-leptonic B decays provide new constraints on CP
observables in decay B to a0(980)(to eta pi) pi. The kinematics of this decay
do not allow interference between the oppositely charged resonances in the
Dalitz plot as in B0 to rho(770)pi. Nonetheless, under the assumption of
factorization,the a0pi two-body time-dependent isospin analysis leads to a more
robust extraction of the angle alpha than in the rhopi isospin-pentagon
analysis. The absence of second class currents might lead to enhanced direct CP
violation and/or allows for a test of some assumptions made in the alpha
analysis in other decays like B to a0rho, B to b1(1235)pi, B to a0 a0, B to
eta(eta')pipi and B to b1 a0. The effects from non-factorizable contributions
on the determination of alpha are estimated by means of a numerical study.


title:
Strange Quark Mass from the Invariant Mass Distribution of
  Cabibbo-Suppressed Tau Decays

abstract:
  Quark mass corrections to the tau hadronic width play a significant role only
for the strange quark, hence providing a method for determining its mass. The
experimental input is the vector plus axial-vector strange spectral function
derived from a complete study of tau decays into strange hadronic final states
performed by ALEPH. New results on strange decay modes from other experiments
are also incorporated. The present analysis determines the strange quark mass
at the Mtau mass scale using moments of the spectral function. Justified
theoretical constraints are applied to the nonperturbative components and
careful attention is paid to the treatment of the perturbative expansions of
the moments which exhibit convergence problems. The result obtained,
m_s(Mtau^2) = (120 +- 11_exp +- 8_Vus +- 19_th) MeV = (120^+21_-26) MeV, is
stable over the scale from Mtau down to about 1.4 GeV. Evolving this result to
customary scales yields m_s(1 GeV^2) = (160^+28_-35) MeV and m_s(4 GeV^2) =
(116^+20_-25) MeV.


title: Solving the strong CP problem with supersymmetry

abstract:
  We propose a new solution to the strong CP problem based on supersymmetric
non-renormalization theorems. CP is broken spontaneously and it's breaking is
communicated to the MSSM by radiative corrections. The strong CP phase is
protected by a susy non-renormalization theorem and remains exactly zero while
loops can generate a large CKM phase from wave function renormalization. We
present a concrete model as an example but stress that our framework is
general. We also discuss constraints on susy breaking and point out
experimental signatures.


title: Static properties of chiral models with SU(3) group structure

abstract:
  We investigate the strangeness in the framework of chiral models, such as the
Skyrmion, MIT bag, chiral bag and superqualiton models, with SU(3) flavor group
structure. We review the recent progresses in both the theoretical paradigm and
experimental verification for strange hadron physics, and in particular the
SAMPLE experiment results on the proton strange form factor. We study the color
flavor locking phase in the color superconducting quark matter at high density,
which might exist in the core of neutron stars, in the soliton-like
superqualiton description. We explain the difficulties encountered in the
application of the standard Dirac quantization to the Skyrmion and
superqualiton models and treat the geometrical constraints of these soliton
models properly to yield the relevant mass spectrum including the Weyl ordering
corrections and the BRST symmetry structures.


title: Exploring timelike exclusive processes in the light-front approach

abstract:
  We discuss a necessary nonvalence contribution in timelike exclusive
processes. Utilizing a Schwinger-Dyson type of approach, we relate the
nonvalence contribution to an ordinary light-front wave function that has been
extensively tested in the spacelike exclusive processes. An application to
$K_{\ell3}$ decays provides encouraging results.


title: Basic Structure in Hadrons

abstract:
  We have calculated the Structure function a constituent quark in the NLO and
from it we have derived the structure functions of hadrons. We found that
perturbative generation of hadron structure falls short of conforming with data
by a few percent. This is due to the presence of soft gluon and its radiation
in the hadron. This contribution is modeled into our calculations. It is also
responsible for the breaking of flavor symmetry in the nucleon sea.


title: Can One See the Number of Colors?

abstract:
  We formulate the standard model with an arbitrary number of colors N_c. The
cancellation of Witten's global SU(2)_L anomaly requires N_c to be odd, while
the cancellation of triangle anomalies determines the consistent N_c-dependent
values of the quark charges. In this theory, the width of the neutral pion
decay into two photons is not proportional to (N_c)^2. In fact, in the case of
a single generation and hence for two quark flavors (N_f = 2), N_c does not
appear explicitly in the low-energy effective theory of the standard model.
Hence, contrary to common lore, it is impossible to see the number of colors in
low-energy experiments with just pions and photons. For N_f > 2, on the other
hand, N_c explicitly enters the chiral Lagrangian as the quantized prefactor of
the Wess-Zumino-Witten term, but the contribution of this term to photon-pion
vertices is completely canceled by the N_c-dependent part of a
Goldstone-Wilczek term. However, the width of the eta decay into pi^+ pi^-
gamma survives the cancellation and is indeed proportional to (N_c)^2. By
detecting the emerging photon, this process thus allows one to literally see
N_c for N_f > 2.


title:
Perturbative QCD and factorization of coherent pion photoproduction on
  the deuteron

abstract:
  We analyze the predictions of perturbative QCD for pion photoproduction on
the deuteron, gamma D -> pi^0 D, at large momentum transfer using the reduced
amplitude formalism. The cluster decomposition of the deuteron wave function at
small binding only allows the nuclear coherent process to proceed if each
nucleon absorbs an equal fraction of the overall momentum transfer.
Furthermore, each nucleon must scatter while remaining close to its mass shell.
Thus the nuclear photoproduction amplitude, M_{gamma D -> pi^0 D}(u,t),
factorizes as a product of three factors: (1) the nucleon photoproduction
amplitude, M_{gamma N_1 -> pi^0 N_1}(u/4,t/4), at half of the overall momentum
transfer, (2) a nucleon form factor, F_{N_2}(t/4), at half the overall momentum
transfer, and (3) the reduced deuteron form factor, f_d(t), which according to
perturbative QCD, has the same monopole falloff as a meson form factor. A
comparison with the recent JLAB data for gamma D -> pi^0 D of Meekins et al.
[Phys. Rev. C 60, 052201 (1999)] and the available gamma p -> pi^0 p data shows
good agreement between the perturbative QCD prediction and experiment over a
large range of momentum transfers and center of mass angles. The reduced
amplitude prediction is consistent with the constituent counting rule, p^11_T
M_{gamma D -> pi^0 D} -> F(theta_cm), at large momentum transfer. This is found
to be consistent with measurements for photon lab energies E_gamma > 3 GeV at
theta_cm=90 degrees and $\elab > 10$ GeV at 136 degrees.


title:
B-meson dileptonic decays enhanced by supersymmetry with large
  $\tan\beta$

abstract:
  We examined the rare decays $B\to X_s\ell^+\ell^-$ and
$B_s\to\ell^+\ell^-\gamma$ in the minimal supersymmetric model with large
$\tan\beta$. Taking into account the gluino-loop and neutralino-loop effects,
we found that for a large $\tan\beta$ the neutral Higgs exchanging diagrams
could enhance $Br(B\to X_s\tau^+\tau^-)$ by a factor of 5 and
$Br(B_s\to\tau^+\tau^-\gamma)$ by a couple of orders in some part of
supersymmetric parameter space allowed by current experiments such as $b\to
s\gamma, B\to K^{(*)}\ell^+\ell^-$ and $B_s\to\ell^+\ell^-$. The
forward-backward asymmetry and the distributions of differential branching
ratios are also found to differ significantly from the standard model results.
  Such enhanced branching ratios reach the level of $10^{-5}$ and thus might be
observable in the new generation of B experiments.


title:
Neutrino Oscillations: Status, Prospects and Opportunities at a Neutrino
  Factory

abstract:
  We review the current status of neutrino oscillations after 1258 days of
Super-Kamiokande, assess their future prospects over the next 10 years as the
next generation of experiments come on-line, and discuss the longer-term
opportunities presented by a Neutrino Factory. We also give an introduction to
the see-saw mechanism and its application to atmospheric and solar neutrinos.


title: CP and Flavour in Effective Type I String Models

abstract:
  Effective type I string models allow stabilization of the dilaton and moduli
fields with only a single gaugino condensate. We show that, as well as breaking
supersymmetry, the stabilization can spontaneously break CP. We find that this
source of CP violation hints strongly at a natural solution to the
supersymmetric CP and flavour problems. Even though the CP violation generates
physical phases in the Yukawa couplings, all the supersymmetry breaking terms
are found to be automatically real and given by the U(1) charges of the
associated Yukawa couplings. These can be chosen to have a structure
(degenerate or non-universal) which suppresses FCNCs and EDMs. We examine the
phenomenological implications, including the generation of the $\mu$-term, and
the effect of higher order terms.


title:
Percolation of strings and the first RHIC data on multiplicity and
  tranverse momentum distributions

abstract:
  The dependence of the multiplicity on the number of collisions and the
transverse momentum distribution for central and peripheral Au-Au collisions
are studied in the model of percolation of strings relative to the experimental
conditions at RHIC. The comparison with the first RHIC data shows a good
agreement.


title:
Slope of the topological susceptibility at zero temperature and finite
  temperature in the Nambu-Jona-Lasinio model

abstract:
  We estimate the slope of the topological susceptibility in the three flavour
Nambu-Jona-Lasinio model with the 't Hooft interaction. The results are
consistent with the evaluation from the QCD sum rule in favour of the full
topological susceptibility. We apply it to the Shore-Veneziano formula to find
that it shows satisfactory agreement with the anomalous suppression of the
flavour-singlet axial charge. The behaviour at finite temperature is also
discussed.


title: A Neutrino Factory Manifesto

abstract:
  A neutrino factory is capable of answering basic questions in the physics of
neutrino oscillations, which address fundamental issues in Grand Unified
Theories and flavour physics. In addition, the front end of a neutrino factory
offers exciting prospects using slow and stopped muons, such as the search for
mu to e transitions and the muon electric dipole moment. There are also
opportunities to study muonic atoms and in other areas of science. One should
also keep in mind the long-term objective of building a muon collider, either
for Higgs physics or at the high-energy frontier.


title: Light Higgs Boson in the Spontaneously CP Violating NMSSM

abstract:
  We consider spontaneous CP violation in the Next to Minimal Supersymmetric
Standard Model, without the usual $Z_3$ discrete symmetry. CP violation can
occur at tree level, raising a potential conflict with the experimental bounds
on the electric dipole moments of the electron and neutron. One escape from
this is to demand that the CP violating angles are small, but we find that this
entails a light neutral Higgs particle. This is almost pseudoscalar, can have a
high singlet content, and will be hard to detect experimentally.


title: On the theoretical uncertainties in the muon anomalous magnetic moment

abstract:
  I present a fairly detailed discussion of various contributions to the
anomalous magnetic moment of the muon a_mu. I try to give an unbiased
evaluation of the validity of the SM prediction for this quantity and to point
out some delicate issues involved in its calculation. I conclude that the
theory uncertainties in the SM prediction for the muon anomalous magnetic
moment are underestimated and a great deal of work will be required to reduce
these uncertainties to the level required by experiment.


title: How Protons Shatter Colored Glass

abstract:
  We consider the implications of the Color Glass Condensate for the central
region of p+A collisions. We compute the k_t distribution of radiated gluons
and their rapidity distribution dN/dy analytically, both in the perturbative
regime and in the region between the two saturation momenta. We find an
analytic expression for the number of produced gluons which is valid when the
saturation momentum of the proton is much less than that of the nucleus. We
discuss the scaling of the produced multiplicity with A. We show that the slope
of the rapidity density dN/dy provides an experimental measure for the
renormalization-group evolution of the color charge density of the Color Glass
Condensate (CGC). We also argue that these results are easily generalized to
collisions of nuclei of different A at central rapidity, or with the same A but
at a rapidity far from the central region.


title: Solar and Atmospheric Four-Neutrino Oscillations

abstract:
  We present an analysis of the neutrino oscillation solutions of the solar and
atmospheric neutrino problems in the framework of four-neutrino mixing where a
sterile neutrino is added to the three standard ones and the mass spectra
presents two separated doublets. Such scenarios allow for simultaneous
transitions of solar $\nu_e$, as well as atmospheric $\nu_\mu$, into active and
sterile neutrinos controlled by the additional mixing angles $\vartheta_{23}$
and $\vartheta_{24}$, and they contain as limiting cases the pure solar
$\nu_e$-active and $\nu_e$-sterile neutrino oscillations, and the pure
atmospheric $\nu_\mu\to\nu_s$ and $\nu_\mu\to\nu_\tau$ oscillations,
respectively. We evaluate the allowed active-sterile admixture in both solar
and atmospheric oscillations from the combined analysis. Our results show that,
although the Super-Kamiokande data disfavour both the pure $\nu_\mu\to\nu_s$
atmospheric channel and the pure $\nu_e\to\nu_s$ solar channel, the result from
the combined analysis still favours close-to-pure active and sterile
oscillations and disfavours oscillations into a near-maximal active-sterile
admixture.


title: How natural is a small \bar\theta in left-right SUSY models ?

abstract:
  In the world without an axion the smallness of $\bar\theta$ may be achieved
due to a spontaneously broken discrete left-right symmetry. We analyze the
radiatively induced \bar\theta in the context of generic left-right symmetric
SUSY models without assuming flavor degeneracy in the squark sector. Left-right
symmetry allows to keep \bar\theta within its present bound only if the
inter-generational mass splitting in the squark sector at the scale of the
left-right symmetry breaking is smaller than 0.5%. We also consider the
naturalness of m_u=0 solution to the strong CP problem in the context of
horizontal flavor symmetries. A strong bound on the combination of the
horizontal charges in the Up quark sector is found in this case.


title: Prompt Atmospheric Neutrinos: Phenomenology and Implications

abstract:
  We present an overview of the phenomenology of prompt neutrinos produced in
the atmosphere by the decay of charmed particles. In face of the great activity
involving operational and proposed large scale neutrino telescopes, we discuss
the implications of different scenarios in calculating the prompt flux, upon
the detectable signals in these experiments.


title:
Formation and Collapse of False Vacuum Bubbles in Relativistic Heavy-Ion
  Collisions

abstract:
  It is possible that under certain situations, in a relativistic heavy-ion
collision, partons may expand out forming a shell like structure. We analyze
the process of hadronization in such a picture for the case when the
quark-hadron transition is of first order, and argue that the inside region of
such a shell must correspond to a supercooled (to $T = 0$) deconfined vacuum.
Hadrons from that region escape out, leaving a bubble of pure deconfined vacuum
with large vacuum energy. This bubble undergoes relativistic collapse, with
highly Lorentz contracted bubble walls, and may concentrate the entire energy
into extremely small regions. Eventually different portions of bubble wall
collide, with the energy being released in the form of particle production.
Thermalization of this system can lead to very high temperatures. With a
reasonably conservative set of parameters, at LHC, the temperature of the hot
spot can reach as high as 3 GeV, and well above it with more optimistic
parameters. Such a hot spot can leave signals like large $P_T$ partons,
dileptons, and enhanced production of heavy quarks. We also briefly discuss a
speculative possibility where the electroweak symmetry may get restored in the
highly dense region resulting from the decay of the bubble wall via the
phenomenon of non-thermal symmetry restoration (which is usually employed in
models of pre-heating after inflation). If that could happen then the
possibility may arise of observing sphaleron induced baryon number violation in
relativistic heavy-ion collisions.


title: Production of the D-wave $b \bar b$ states

abstract:
  The first and second families of D-wave $b \bar b$ quarkonium states are
expected to have masses near 10.16 and 10.44 GeV/$c^2$. The accuracy of these
predictions is discussed, and the prospects of two methods for producing these
states in electron-positron collisions are updated. Direct scans in the $e^+
e^-$ center-of-mass can give rise to the $^3D_1$ states. The $1^3D_J$ states
have also been searched for in the electromagnetic cascades from $\ups(3S) \to
\gamma \chi'_b \to \gamma \gamma ^3D_J$. The sample of $\ups(3S)$ decays
required to definitively observe the $1^3D_J$ states is found to be only
somewhat greater than the present world's total.


title: New Dimensions New Hopes

abstract:
  We live in a four dimensional world. But the idea of unification of
fundamental interactions lead us to higher dimensional theories. Recently a new
theory with extra dimensions has emerged, where only gravity propagates in the
extra dimension and all other interactions are confined in only four
dimensions. This theory gives us many new hopes. In earlier theories
unification of strong, weak and the electromagnetic forces was possible at
around (10^{16}) GeV in a grand unified theory (GUT) and it could get unified
with gravity at around the Planck scale of (10^{19}) GeV. With this new idea it
is possible to bring down all unification scales within the reach of the next
generation accelerators, i.e., around $10^4$ GeV.


title: A New Fit to Solar Neutrinos Using Extra Dimensions

abstract:
  A neutrino mass-mixing scheme which explains qualitatively all present
evidence for neutrino mass (the solar and atmospheric neutrino deficits, LSND,
and hot dark matter), and also makes possible heavy-element nucleosynthesis by
supernovae, requires at least one light sterile neutrino. String-inspired
models with sub-millimeter extra dimensions provide naturally light sterile
neutrinos, as is needed to explain the solar nu_e deficit. This bulk sterile
neutrino provides a better fit to the solar data than conventional models by
having vacuum oscillations of the nu_e to its zero mode and MSW oscillations to
its first few Kaluza-Klein modes. While the prediction of the Super-Kamiokande
energy spectrum gives a fit probability of 73%, the superior energy resolution
of SNO's charged-current spectrum will determine whether this neutrino scheme
is correct and can demonstrate that an extra dimension of ~60 mu m exists.
Should this be the case, there are important implications for supernovae,
ultra-high-energy cosmic rays, double beta decay, and dark matter.


title: Transverse Resummation for Direct Photon Production

abstract:
  Quantum Chromodynamics predicts radiative terms which, at low transverse
momentum of an observed multi-particle system, can be large enough to threaten
the legitimacy of a fixed-order perturbative treatment. We present a
subtraction-style calculation which sums these terms to all orders for a direct
photon plus jet final state, and show that the kinematic effect of such a
resummation is significant even after integration over the jet. An improved
matching algorithm is prescribed for the transition to the perturbative regime,
and re-examination of the nonperturbative regime indicates that simple Gaussian
parametrizations are to be favored, with coefficients that depend not on the
photon-jet mass, but on the color structure of the initiated subprocess.
Agreement with data is significantly improved, and the method is expected to
have applicability in general for processes with steeply-falling spectra.


title:
Regge models of the proton structure function with and without hard
  Pomeron: a comparative analysis

abstract:
  A comparative phenomenological analysis of Regge models with and without a
hard Pomeron component is performed using a common set of recently updated
data. It is shown that the data at small $x$ do not indicate explicitly the
presence of the hard Pomeron. Moreover, the models with two soft-Pomeron
components (simple and double poles in the angular momentum plane) with
trajectories having intercept equal one lead to the best description of the
data not only at $W>3$ GeV and at small $x$ but also at all $x\leq 0.75$ and
$Q^{2}\leq 30000$ GeV$^{2}$.


title:
Supersymmetric Model of Neutrino Mass and Leptogenesis with String-Scale
  Unification

abstract:
  Adjoint supermultiplets (1,3,0) and (8,1,0) modify the evolution of gauge
couplings. If the unification of gauge couplings occurs at the string scale,
their masses are fixed at around $10^{13}$ GeV. This scale coincides with
expected gaugino condensation scale in the hidden sector $M_{string}^{2/3}
m^{1/3}_{3/2} \sim 10^{13}$ GeV. We show how neutrino masses arise in this
unified model which naturally explain the present atmospheric and solar
neutrino data. The out-of-equilibrium decay of the superfield (1,3,0) at
$10^{13}$ GeV may also lead to a lepton asymmetry which then gets converted
into the present observed baryon asymmetry of the Universe.


title: Rare (B -> l^+ l^- gamma) decay and new physics effects

abstract:
  Using the most general, model independent form of the effective Hamiltonian
rare decays (B -> l^+ l^- gamma (l=mu, tau)) are studied. The sensitivity of
the photon energy distribution and branching ratio to the new Wilson
coefficients is investigated.


title:
Spontaneous Symmetry Broken Condition in (De)Constructing Dimensions
  from Noncommutative Geometry

abstract:
  In this short report, a brief introduction to Arkani-Hamed, Cohen, Georgi
model (ACG-model, (de)constructing dimensions model), whose main characters are
that extra-dimensional space-time are generated dynamically from a
four-dimensional gauge theory and that extra dimensions are lattices, will be
given first. Then after a concise review of NCG on cyclic groups, actions for
gauge fields along extra dimensions will be constructed by virtue of NCG and
classical (vacuum) solutions will be solved, with low energy phenomenology
being classified accordingly. As a conclusion, the behavior of spontaneous
symmetry broken within ACG-model can be determined by noncommutative Yang-Mills
theory.


title:
Naturally Light Neutrinos and Unification in Theories with Low Scale
  Quantum Gravity

abstract:
  Within low scale theories traditional see-saw and scalar triplet mechanisms,
for neutrino mass suppression, do not work out anymore and for realistic model
building some new ideas are needed. In this paper we suggest mechanism,
different from existing ones, which provides natural suppression of the
neutrino masses. The mechanism is realized through extended scalars of 4, 5 or
6 dimensional $SU(2)_L$ multiplets. Scenario, with fundamental mass scale $M_f$
in a $\sim 10^{3}$ TeV range, requires 4-plets guaranteeing neutrino masses
$\stackrel{<}{\sim}1$ eV. For theories with $M_f= few \cdot 10$ TeV 5-plets
should be involved, while in scenarios with $M_f=$ few TeV, 6-plets could be
efficient.
  The considered mechanism could be successfully applied also for
supersymmetric theories, building scenarios with various values of low $M_f$.
  Within considered models we also address the question of gauge coupling
unification. For low scale unification, existence of compact extra dimensions
turns out to be crucial. Due to additional scalar multiplets, some new examples
of unification are found for both - non SUSY and SUSY cases. Within non SUSY
scenarios introduced $SU(2)_L$ scalars take advantage and are important for
successful unification.


title: Theoretical issues at LEP2 and LC

abstract:
  After 12 years of glorious data taking LEP has been shut down. During the
past two years an incredible effort has been devoted to get more accurate
predictions and estimates of the related theoretical uncertainties. Many of the
theoretical questions driven by LEP are also relevant at the LC, where
predictions will be needed with even higher accuracy. This is particularly true
for 4-fermion Physics. In this contribution, I review some of the most
important theoretical achievements at LEP in understanding W and Z pair
production, 4-fermion + 1 visible photon signatures and in solving problems
related with gauge invariance. Issues on single W Physics are covered
elsewhere.
  Part of the presented work is in progress, the final LEP2 analysis still
being under way.


title: The Effective Fine Structure Constant at TESLA Energies

abstract:
  We present a new estimate of the hadronic contribution to the shift in the
fine structure constant at LEP and TESLA energies and calculate the effective
fine structure constant. Substantial progress in a precise determination of
this important parameter is a consequence of substantially improved total cross
section measurements by the BES II collaboration and an improved theoretical
understanding. In the standard approach which relies to a large extend on
experimental data we find $\Delta \al_{\rm hadrons}^{(5)}(\mz) = 0.027896 \pm
0.000395$ which yields $\alpha^{-1}(\mz) = 128.907 \pm 0.054$. Another
approach, using the Adler function as a tool to compare theory and experiment,
allows us to to extend the applicability of perturbative QCD in a controlled
manner. The result in this case reads $\Delta\alpha^{(5)}_{\rm had}(M_Z^2) =
0.027730 \pm 0.000209$ and hence $\alpha^{-1}(\mz) = 128.930 \pm 0.029$. At
TESLA energies a new problem shows up with the definition of an effective
charge. A possible solution of the problem is presented. Prospects for further
progress in a precise determination of the effective fine structure constant
are discussed.


title: Collisional Dark Matter and Scalar Phantoms

abstract:
  As has been previously proposed, a minimal modification of the standard
$SU(3)\times SU(2)\times U(1)$ theory provides a viable dark matter candidate.
Such a particle, a scalar gauge singlet, is naturally self-interacting---making
it of particular interest given recent developments in astrophysics. We review
this dark matter candidate, with reference to the parameter ranges currently
under discussion.


title: CP violation and modular symmetries

abstract:
  We reconsider the origin of CP violation in fundamental theory. Existing
string models of spontaneous CP violation make ambiguous predictions, due to
the arbitrariness of CP transformation and the apparent non-invariance of the
results under duality. We find an unambiguous modular CP invariance condition,
applicable to predictive models of spontaneous CP violation, which circumvents
these problems; it strongly constrains CP violation by heterotic string moduli.
The dilaton is also evaluated as a source of CP violation, but is likely
experimentally excluded. We consider the prospects for explaining CP violation
in strongly-coupled strings and brane worlds.


title:
Functional Integral Method in Quantum Theory of Composite Particles and
  Quasiparticles

abstract:
  In this series of lectures we present the universal method based on the use
of the functional integrals to derive the bound state equations for different
two-body systems in elementary particle physics as well as in condensed matter
theory: the relativistic Nambu-Jona-Lasinio equation and the relativistic
Bethe-Salpeter equation in elementary particle physics, the Bethe-Salpeter
equation for the bipolaritons. The bound state equation for the three-body
systems is also established.


title:
Mixing Matrix of Quarks Having Natural Twisting in E_6 Grand Unified
  Model

abstract:
  Mass matrix of quarks is studied in the Supersymmetric $E_6$ Grand Unified
Theory (GUT). The fundamental representation $\textbf{27}$ in $E_6$ which
corresponds to one generation contains two sets of $\textbf{5}^{*}$'s in SU(5),
so that there are six flavors of lepton doublets and right-handed down-quark
triplets. It is known that the twisting (interchange) among the
$\textbf{5}^{*}$ representations may reproduce the observed quark and lepton
mixing matrices. If $E_6$ is directly broken down to $SU(3)_C \times SU(2)_L
\times U(1)_Y$ and two extra U(1)'s, the extra 3 sets of down-type quarks do
not necessarily decouple from the quark mass matrix, under the appropriate
choice of the U(1) flavor charges on the quark and Higgs fields. Then, by
diagonalizing the 6 $\times$ 6 down-quark mass matrix, we find a certain set of
parameters, in which the twisting between a pair of the right-handed
down-quarks occurs naturally, reproducing the reasonable values for the $d$-,
$s$- and $b$-quark masses, and for $V_{ud}$, $V_{us}$, $V_{cd}$, $V_{cs}$ and
$V_{tb}$ of the CKM matrix elements. As a by-product, one vector-like
down-quark appears at the experimentally accessible TeV scale.


title: Neutrino anomalies and large extra dimensions

abstract:
  Theories with large extra dimensions can generate small neutrino masses when
the standard model neutrinos are coupled to singlet fermions propagating in
higher dimensions. The couplings can also generate mass splittings and mixings
among the flavour neutrinos in the brane. We systematically study the minimal
scenario involving only one singlet bulk fermion coupling weakly to the flavour
neutrinos. We explore the neutrino mass structures in the brane that can
potentially account for the atmospheric, solar and LSND anomalies
simultaneously in a natural way. We demonstrate that in the absence of a priori
mixings among the SM neutrinos, it is not possible to reconcile all these
anomalies. The presence of some structure in the mass matrix of the SM
neutrinos can solve this problem. This is exemplified by the Zee model, which
when embedded in extra dimensions in a minimal way can account for all the
neutrino anomalies.


title: Chiral corrections to baryon properties with composite pions

abstract:
  A calculational scheme is developed to evaluate chiral corrections to
properties of composite baryons with composite pions. The composite baryons and
pions are bound states derived from a microscopic chiral quark model. The model
is amenable to standard many-body techniques such as the BCS and RPA
formalisms. An effective chiral model involving only hadronic degrees of
freedom is derived from the macroscopic quark model by projection onto hadron
states. Chiral loops are calculated using the effective hadronic Hamiltonian. A
simple microscopic confining interaction is used to illustrate the derivation
of the pion-nucleon form factor and the calculation of pionic self-energy
corrections to the nucleon and Delta(1232) masses.


title: Detection of a Hypercharge Axion in ATLAS

abstract:
  This Master of Science thesis treats the hypercharge axion, which is a
hypothetical pseudo-scalar particle with electroweak interactions.
  First, the theoretical context and the motivations for this study are
discussed. In short, the hypercharge axion is introduced to explain the
dominance of matter over antimatter in the universe and the existence of
large-scale magnetic fields.
  Second, the phenomenological properties are analyzed and the distinguishing
marks are underlined. These are basically the products of photons and $Z^0$s
with high transverse momenta and invariant mass equal to that of the axion.
  Third, the simulation is carried out with two photons producing the axion
which decays into $Z^0$s and/or photons. The event simulation is run through
the simulator ATLFAST of ATLAS (A Toroidal Large Hadron Collider ApparatuS) at
CERN.
  Finally, the characteristics of the axion decay are analyzed and the criteria
for detection are presented. A study of the background is also included. The
result is that for certain values of the axion mass and the mass scale (both in
the order of a TeV), the hypercharge axion could be detected in ATLAS.


title:
Subtraction method for NLO corrections in Monte-Carlo event generators
  for Z boson production

abstract:
  We use a subtraction method to construct NLO corrections in a Monte-Carlo
event generator for the case of vector boson production in Drell-Yan processes.
Our calculations are carried out both for the Bengtsson-Sjostrand-van Zijl
(BSZ) algorithm and for a modified algorithm proposed by Collins. In the case
of the modified algorithm, we compute the relation between the parton
distribution functions and the ones in the MSbar scheme; this relation is the
same as the corresponding relation for DIS. For the BSZ algorithm, we show that
there is no simple relation.


title: Bounds on flavour violating parameters in supersymmetry

abstract:
  We investigate the constraints on the flavour violating parameters from the
decay B --> X_s gamma, taking into account the interplay of the various sources
of flavour violation in the unconstrained MSSM. We present a systematic leading
logarithmic QCD analysis of these model-independent constraints, including
contributions from gluinos, neutralinos, charginos, charged Higgs bosons and
interferences between them. We show that two simple combinations of elements of
the down squark mass matrix are stringently bounded over large parts of the
parameter space where only weak assumptions on the hierarchical structure of
the squark mass matrices are made. We also briefly analyse up to which values
SUSY contributions, compatible with B --> X_s gamma, can enhance the Wilson
coefficient C_8(m_W), which plays an important role in the phenomenology of
charmless hadronic B decays.


title:
Reconstruction of the Earth's matter density profile using a single
  neutrino baseline

abstract:
  In this paper, we show numerically that a symmetric Earth matter density
profile can, in principle, be reconstructed from a single baseline energy
spectrum up to a certain precision. For the numerical evaluations in the high
dimensional parameter space we use a genetic algorithm.


title: Status of the Gribov-Pontecorvo Solution to the Solar Neutrino Problem

abstract:
  We discuss the status of the Gribov-Pontecorvo (GP) solution to the solar
neutrino problem. This solution naturally appears in bimaximal neutrino mixing
and reduces the solar and atmospheric neutrino problems to vacuum oscillations
of three active neutrinos. The GP solution predicts an energy-independent
suppression of the solar neutrino flux. It is disfavoured by the rate of the
Homestake detector, but its statistical significance greatly improves, when the
chlorine rate and the boron neutrino flux are slightly rescaled, and when the
Super-Kamiokande neutrino spectrum is included in the analysis. Our results
show that rescaling of the chlorine signal by only 10% is sufficient for the GP
solution to exist, if the boron-neutrino flux is taken 10 -- 20% lower than the
SSM prediction. The regions allowed for the GP solution in the parameter space
are found and observational signatures of this solution are discussed.


title:
First principle derivation of semiclassical force for electroweak
  baryogenesis

abstract:
  We perform a systematic gradient expansion on kinetic equations and derive
the CP-violating semiclassical force for fermions propagating in presence of a
CP-violating wall at a first order electroweak phase transition. The force
appears at order h-bar in the flow term of the kinetic equation and agrees with
the semiclassical force used for baryogenesis computations. In particular we
consider the force for charginos in both the MSSM and NMSSM. We then study the
continuity equations for the vector and axial vector currents and stress the
role of the latter as the one containing baryogenesis sources. We also show
that there is no CP-violating force for bosons to order h-bar in gradient
expansion.


title:
Large-N_c Quark Distributions in the Delta and Chiral Logarithms in
  Quark Distributions of the Nucleon

abstract:
  In a world with two quark flavors and a large number of colors (N_c), the
polarized and unpolarized quark distributions in the delta are completely
determined by those in the nucleon up to {\cal O}(1/N_c). In particular, we
find q_{\Delta}(x) =[(1\pm 2T_z)u_N(x)+ (1\mp 2T_z)d_N(x)]/2 and \Delta
q_\Delta(x) =[(5\pm 2T_z)\Delta u_N(x) + (5\mp 2T_z)\Delta d_N(x)]/10, where q
= u, d and $T_z$ the charge state of a delta. The result can be used to
estimate the leading chiral-logarithmic corrections to the quark distributions
in the nucleon.


title: Physics Potential of Very Intense Conventional Neutrino Beams

abstract:
  The physics potential of high intensity conventional beams is explored. We
consider a low energy super beam which could be produced by a proposed new
accelerator at CERN, the Super Proton Linac. Water Cherenkov and liquid oil
scintillator detectors are studied as possible candidates for a neutrino
oscillation experiment which could improve our current knowledge of the
atmospheric parameters and measure or severely constrain the parameter
connecting the atmospheric and solar realms. It is also shown that a very large
water detector could eventually observe leptonic CP violation. The reach of
such an experiment to the neutrino mixing parameters would lie in-between the
next generation of neutrino experiments (MINOS, OPERA, etc) and a future
neutrino factory.