title:
Muon anomalous magnetic moment in supersymmetric scenarios with an
  intermediate scale and nonuniversality

abstract:
  We analyze the anomalous magnetic moment of the muon (a_{\mu}) in
supersymmetric scenarios. First we concentrate on scenarios with universal soft
terms. We find that a moderate increase of a_{\mu} can be obtained by lowering
the unification scale M_{GUT} to intermediate values 10^{10-12} GeV. However,
large values of \tan \beta are still favored. Then we study the case of
non-universal soft terms. For the usual value M_{GUT}~10^{16} GeV, we obtain
a_{\mu} in the favored experimental range even for moderate \tan \beta regions
\tan\beta ~ 5$. Finally, we give an explicit example of these scenarios. In
particular, we show that in a D-brane model, where the string scale is
naturally of order 10^{10-12} GeV and the soft terms are non universal, a_{\mu}
is enhanced with low \tan\beta.


title:
Supersymmetric enhancement of associated ZA^0 production at e^+e^-
  colliders

abstract:
  We study the associated production of the A^0 neutral CP-odd Higgs boson with
a neutral gauge boson Z in high energy e^+ e^- collisions at the one loop
level. We present a detailed discussion for the total cross-section predicted
in the context of the Minimal Supersymmetric Standard Model (MSSM) and make a
comparison with the non-SUSY Two Higgs Doublet Model (THDM). We show that the
MSSM cross-section may be enhanced compared to that for the THDM.


title: Natural Relations in the Standard Model

abstract:
  We establish the potential existence of natural relations between the Cabibbo
angle and the quark mass ratios, in a Standard Model with one Higgs doublet and
two quark generations. The argument is based on the calculation of the
divergent one-loop radiative corrections to the quark mass matrices.


title: Top Quark Production at TeV Energies as a Potential SUSY Detector

abstract:
  We consider the process of top-antitop production from electron-positron
annihilation, for c. m. energies in the few TeV regime, in the MSSM theoretical
framework. We show that, at the one loop level, the \underline{slopes} of a
number of observable quantities in an energy region around 3 TeV are only
dependent on $\tan\beta$. Under optimal experimental conditions, a combined
measurement of slopes might identify $\tan\beta$ values in a range $\tan\beta<
2$, $\tan\beta>20$ with acceptable precision.


title: Extrapolating Structure Functions to Very Small x

abstract:
  We review small $x$ contributions to perturbative evolution equations for
parton distributions, and their resummation. We emphasize in particular the
resummation technique recently developed in order to deal with the apparent
instability of naive small $x$ evolution kernels and understand the empirical
sucess of fixed--order perturbation theory. We give predictions for the gluon
distribution and the structure functions F_2(x,Q^2) and F_L(x,Q^2) in an
extended kinematic region, such as would be relevant for THERA or LEP+LHC ep
colliders.


title:
Three loop gauge beta-function for the most general single
  gauge-coupling theory

abstract:
  We calculate the three loop contribution to the beta-function of the gauge
coupling constant in a general, anomaly-free, renormalisable gauge field theory
involving a single gauge coupling using the background field method in the
MSbar scheme.


title: Gravitational couplings of charged leptons in a medium

abstract:
  We calculate the leading order matter-induced corrections to the
gravitational interactions of charged leptons and their antiparticles in a
medium that contains electrons but not the other charged leptons, such as
normal matter. The gravitational coupling, which is universal at the tree
level, is found to be flavor-dependent, and also different for the
corresponding antiparticles, when the corrections of $O(\alpha)$ are taken into
account. General expressions are obtained for the matter-induced corrections to
the gravitational mass in a generic matter background, and explicit formulas
for those corrections are given in terms of the macroscopic parameters of the
medium for particular conditions of the background gases.


title: Nonperturbative Phenomena and Phases of QCD

abstract:
  Lectures discuss applications of semiclassical methods based on instantons to
vacuum structure (chiral symmetry breaking), hadronic structure (various
correlation functions), and high energy collisions of hadrons and heavy ions.
We discuss phase diagram of hot/dense hadronic matter, and in the last lecture
review current puzzles/lesons from the first RHIC run in summer of 2000.


title: Sensitivity Study of Extra Dimensions at TeV $e^+ e^-$ colliders

abstract:
  We study the sensitivity reach of $0.5-2$ TeV $e^+ e^-$ linear colliders in
the context of the ADD model, in which gravity becomes strong at TeV scale. We
include the real emission channel $e^+ e^- \to \gamma G$, as well as the
virtual-graviton-exchange channels $e^+ e^- \to \gamma \gamma, q\bar q,
\mu^+\mu^-, \tau^+ \tau^-, e^+ e^-$. Assuming no excess of events over the
standard model predictions, we obtain the lower 95% C.L. limits on the
effective Planck scale. These limits are better than those obtained in the Run
II's of the Tevatron and comparable to those of the LHC.


title: Astroparticle physics signals beyond the Standard Model

abstract:
  In this thesis two signals pointing beyond the Standard Model are discussed.
The first signal is the presence of baryonic matter around us. The possibility
of baryogenesis in the Minimal Supersymmetric Standard Model (MSSM) was
studied. The bosonic part of the MSSM Lagrangian was put on the lattice. Finite
temperature and zero temperature simulations were performed to find the jump of
the Higgs length and the mass spectrum. The phase diagram of MSSM in the m_U^2
- T plane was determined. The properties of the bubble wall during the phase
transition were also analyzed. The second signal that is discussed in this
thesis comes from the observed cosmic rays. According to the so-called
''top-down'' scenarios, the highest energy cosmic rays can be the decay
products of some metastable superheavy particle. Based on the clustering
features of the detected events, first the source density was determined. Then
the mass of the decaying superheavy particle was found which is in rough
agreement with the grand unification scale. The lattice simulations of MSSM
require a large amount of CPU time. A PC based supercomputer was built at the
E\"otv\"os University to solve this problem. The hardware and software
architecture as well as the performance of the machine is discussed.


title: Electron-Nucleus Collisions at THERA

abstract:
  The nuclear option at THERA provides an ideal and unique opportunity to
investigate the black body limit (BBL) of high energy Deep Inelastic Scattering
of highly virtual photons off heavy nuclear targets and thereby probe QCD in a
new regime. At high enough energies, whichever hadronic configuration the
photon fluctuates into, the interaction at a given impact parameter with the
heavy nuclear target will eventually reach its geometrical limit corresponding
to the scattering from a black disk. An attractive feature of the BBL regime
for a large nucleus is that the interaction is strong although the coupling
constant is small. Predictions for longitudinal and transverse distributions of
the leading hadrons in inclusive and diffractive channels and exclusive vector
meson production are found to be strikingly different in BBL and the leading
twist approximation. In particular, the multiplicity of leading hadrons in the
current fragmentation region is strongly suppressed, while the cross section of
diffractive vector meson production by longitudinally polarized photons is $
\propto 1/Q^2$. The x and $Q^2$ ranges where BBL maybe reached are calculated
for the interaction of color triplet and color octet dipoles at central impact
parameters. We conclude that for heavy nuclei THERA would reach deep into BBL
for a wide range of $Q^2$. The connection between hard diffraction and leading
twist nuclear shadowing is analysed. It is demonstrated that the current
leading twist analyses of the HERA diffractive data lead to similar and very
large leading twist shadowing for gluons. Several processes sensitive to the
amount of nuclear shadowing for gluons are discussed.


title: Production of the $\eta_b(nS)$ states

abstract:
  The rates for magnetic dipole (M1) transitions $\Upsilon(nS) \to \eta_b(n'S)
+ \gamma$, $n' \le n$, are compared. The photon energies for allowed ($n' = n$)
M1 transitions are very small, so hindered ($n' < n$) transitions could be more
favorable for discovering the $\eta_b(1S,2S)$. The question then arises whether
$\Upsilon(2S)$ or $\Upsilon(3S)$ is a better source of $\eta_b(1S)$. Whereas
one nonrelativistic model favors $\eta_b(1S)$ production from $\Upsilon(2S)$,
this advantage is lost when relativistic corrections are taken into account,
and is not common to all sets of wave functions even in the purely
nonrelativistic limit. Thus, the prospects for discovering $\eta_b(1S)$ in
$\Upsilon(3S)$ radiative decays could be comparable to those in $\Upsilon(2S)$
decays. We also discuss a suggestion for discovering the $\eta_b$ via
$\Upsilon(3S) \to h_b(^1P_1) \pi \pi$, followed by $h_b \to \eta_b \gamma$.


title: Supersymmetric Relations Among Electromagnetic Dipole Operators

abstract:
  Supersymmetric contributions to all leptonic electromagnetic dipole operators
have essentially identical diagramatic structure. With approximate slepton
universality this allows the muon anomalous magnetic moment to be related to
the electron electric dipole moment in terms of supersymmetric phases, and to
radiative flavor changing lepton decays in terms of small violations of slepton
universality. If the current discrepancy between the measured and Standard
Model values of the muon anomalous magnetic moment is due to supersymmetry, the
current bound on the electron electric dipole moment then implies that the
phase of the electric dipole operator is less than $2 \times 10^{-3}$. Likewise
the current bound on $\mu \to e \gamma$ decay implies that the fractional
selectron-smuon mixing in the left-left mass squared matrix, $\delta m_{\smuon
\selectron}^2 / m_{\slepton}^2$, is less than $10^{-4}$. These relations and
constraints are fairly insensitive to details of the superpartner spectrum for
moderate to large $\tan \beta$.


title:
How parametric resonance mechanism follows quench mechanism in
  disoriented chiral condensate

abstract:
  We show how parametric resonance mechanism follows quench mechanism in the
classical linear sigma model. The parametric resonance amplifies long
wavelength modes of the pion for more than $10 fm/c$. The shifting from the
quench mechanism to the parametric resonance mechanism is described by a time
dependent quantity. After the quench mechanism is over, that quantity has an
oscillating part, which causes the parametric resonance. Since its frequency is
$2 m_\pi ~(m_\pi$ : pion mass), very long wavelength modes such as k = 40 MeV
of the pion are amplified by the parametric resonance.


title:
Coherence Phenomena in Charmonium Production off Nuclei at the Energies
  of RHIC and LHC

abstract:
  In the energy range of RHIC and LHC the mechanisms of nuclear suppression of
charmonia are expected to be strikingly different from what is known for the
energy of the SPS. One cannot think any more of charmonium produced on a bound
nucleon which then attenuates as it passes through the rest of the nucleus. The
coherence length of charmonium production substantially exceeds the nuclear
radius in the new energy range. Therefore the production amplitudes on
different nucleons, rather than the cross sections, add up and interfere, i.e.
shadowing is at work. So far no theoretical tool has been available to
calculate nuclear effects for charmonium production in this energy regime. We
develop a light-cone Green function formalism which incorporates the effects of
the coherence of the production amplitudes and of charmonium wave function
formation, and is the central result of this paper. We found a substantial
deviation from QCD factorization, namely, gluon shadowing is much stronger for
charmonium production than it is in DIS. We predict for nuclear effects $x_2$
scaling which is violated at lower energies by initial state energy loss which
must be also included in order to compare with available data. In this paper
only the indirect J/Psi originating from decay of P-wave charmonia are
considered. The calculated x_F-dependence of J/Psi nuclear suppression is in a
good accord with data. We predict a dramatic variation of nuclear suppression
with x_F in pA and a peculiar peak at x_F=0 in AA collisions at RHIC.


title: Scanning the Quark-Gluon Plasma with Charmonium

abstract:
  We suggest the variation of charmonium suppression with Feynman x_F in heavy
ion collisions as a novel and sensitive probe for the properties of the matter
created in such reactions. In contrast to the proton-nucleus case where nuclear
suppression is weakest at small x_F, final state interactions with the comoving
matter create a minimum at x_F=0, which is especially deep and narrow if a
quark-gluon plasma is formed. While a particularly strong effect is predicted
at SPS, at the higher RHIC energy it overlaps with the expected sharp variation
with x_F of nuclear effects and needs comparison with proton-nucleus data. If
thermal enhancement of J/\Psi production takes over at the energies of RHIC and
LHC, it will form an easily identified peak, rather than dip in x_F dependence.
We predict a steep dependence on centrality and suggest that this new probe is
complementary to the dependence on transverse energy, and is more sensitive to
a scenario of final state interactions.


title:
Implications of Muon anomalous magnetic moment for Direct detection of
  Neutralino Dark Matter

abstract:
  We investigate the implications of the recent measurement of muon anomalous
magnetic moment for the direct detection of neutralino dark matter in the three
different SUSY models: mSUGRA, a model with non-universal Higgs mass, and an
SO(10) GUT model. We consider two extreme scenario for $\Delta a_\mu$ bound,
i.e. $27 \times 10^{-10} < \Delta a_\mu < 59 \times 10^{-10}$ (1$\sigma$ bound)
and $0 < \Delta a_\mu < 11 \times 10^{-10}$ ($2\sigma$ below). In mSUGRA model,
the counting ratio may be above the sensitivity of the future experiments when
parameters are within $1\sigma$ bound of $\Delta a_{\mu}$. However, the
$\Omega_{\chi}$ tends to be high compared to the currently favored value
$\Omega=0.3$. For models with the non-universal scalar masses, the possibility
to have the consistent $\Omega_{\chi}$ and the high counting ratio is open up
in the region of parameter space where Higgsino mass $\mu$ is smaller than
mSUGRA prediction. In particular, in the SO(10) model, the LSP dark matter
detection rate may be enhanced by almost one order of magnitude compared to
mSUGRA and the model with non-universal Higgs mass, for cosmologically
acceptable $\Omega_{\chi} h^2$. The highest detection rate of LSP dark matter
occurs in the region where the LSP constitutes a subdominant part of local halo
DM. Implication of SUSY mass parameter measurement under the cosmological
constraint is also discussed.


title:
A Connection Between The Perturbative QCD Potential and Phenomenological
  Potentials

abstract:
  When the cancellation of the leading renormalon contributions is
incorporated, the total energy of a b bbar system, E_{tot,bbbar}(r) = 2
m_{pole,b} + V_QCD(r), agrees well with the potentials used in phenomenological
models for heavy quarkonia in the range 0.5 GeV^-1 < r < 3 GeV^-1. We provide a
connection between the conventional potential-model approaches to the
quarkonium spectroscopy and the recent computation based on perturbative QCD.


title:
Anomalous C-violating Three Photon Decay of the Neutral Pion in
  Noncommutative Quantum Electrodynamics

abstract:
  We show that a simple and reasonable generalization of the anomalous
interaction between the neutral pion and two photons can induce the C-violating
three photon decay of the neutral pion in noncommutative quantum
electrodynamics. We find that it is mandatory for consistency reasons to
include simultaneously the normal neutral pion and photon interaction in which
the neutral pion transforms under U(1) in a similar way as in the adjoint
representation of a non-Abelian gauge theory. We demonstrate that the decay has
a characteristic distribution although its rate still seems too small to be
experimentally reachable in the near future. We also describe how to manipulate
phase space integration correctly when Lorentz invariance is lost.


title:
Combining Parton Showers with Next-to-Leading Order QCD Matrix Elements
  in Deep-Inelastic eP Scattering

abstract:
  We have implemented a systematic procedure for combining parton shower
algorithms with next-to-leading order QCD calculations for the case of jet
production in deep-inelastic electron-proton scattering. Using this method we
have computed inclusive jet cross sections and jet shapes for the case of
single-jet production and compared them to data from the ZEUS collaboration at
HERA. We found good agreement between the data and our calculations, both for
the jet shapes and the inclusive spectra.


title: Ratio of strange to non-strange quark condensates in QCD

abstract:
  Laplace transform QCD sum rules for two-point functions related to the
strangeness-changing scalar and pseudoscalar Green's functions $\psi(Q^2)$ and
$\psi_5(Q^2)$, are used to determine the subtraction constants $\psi(0)$ and
$\psi_5(0)$, which fix the ratio $R_{su}\equiv \frac{<\bar{s}s>}{<\bar{u}u>}$.
Our results are $\psi(0)= - (1.06 \pm 0.21) \times 10^{-3} {GeV}^4$,
$\psi_5(0)= (3.35 \pm 0.25) \times 10^{-3} {GeV}^4$, and $R_{su}\equiv
\frac{<\bar{s}s>}{<\bar{u}u>} = 0.5 \pm 0.1$. This implies corrections to
kaon-PCAC at the level of 50%, which although large, are not inconsistent with
the size of the corrections to Goldberger-Treiman relations in $SU(3)\otimes
SU(3)$.


title:
CP Violation in Kaon System in Supersymmetric SU(5) Model with
  Seesaw-Induced Neutrino Masses

abstract:
  CP violations in the kaon system are studied in supersymmetric SU(5) model
with right-handed neutrinos. We pay a special attention to the renormalization
group effect on the off-diagonal elements of the squark mass matrices. In
particular, if the Yukawa couplings and mixings in the neutrino sector are
sizable, off-diagonal elements of the right-handed down-type squark mass matrix
are generated, which affect CP and flavor violations in decay processes of the
kaon. We calculate supersymmetric contributions to epsilon (as well as Delta
m_K), Br(K_L -> pi^0 nu \bar{nu}), and epsilon'/epsilon in this framework. We
will see that the supersymmetric contribution to the epsilon parameter can be
as large as (and in some case, larger than) the experimentally measured value.
We also discuss its implication to future tests of the unitarity triangle of
the Kobayashi-Maskawa matrix.


title: Rare radiative B decays to orbitally excited K mesons

abstract:
  The exclusive rare radiative B meson decays to orbitally excited axial-vector
mesons K_1^*(1270), K_1(1400) and to the tensor meson K_2^*(1430) are
investigated in the framework of the relativistic quark model based on the
quasipotential approach in quantum field theory. These decays are considered
without employing the heavy quark expansion for the s quark. Instead the s
quark is treated to be light and the expansion in inverse powers of the large
recoil momentum of the final K^{**} meson is used to simplify calculations. It
is found that the ratio of the branching fractions of rare radiative B decays
to axial vector K^*_1(1270) and K_1(1400) mesons is significantly influenced by
relativistic effects. The obtained results for B decays to the tensor meson
K_2^*(1430) agree with recent experimental data from CLEO.


title: Photoproduction of relativistic positronium atoms on extended targets

abstract:
  It is shown that the yield of relativistic positronium atoms in
photoproduction on extended targets is much larger than usually accepted.The
cause of such difference is transparent. At high energies, when the positronium
atom formation time $\tau_f$ becomes greater than the target length L, it is
the free $e^+e^-$ pair that propagates through the target and the formation of
positronium atoms take place out of the target.In the framework of the
light-cone technique we consider the interaction of $e^+e^-$ pair with the
screened Coulomb field of atoms in matter and obtain the analytical expressions
for relativistic positronium atoms photoproduction cross sections on extended
targets.The relations to free pair photoproduction on extended targets are
discussed.


title:
Prospect of a very long baseline neutrino oscillation experiment: HIPA
  to Beijing

abstract:
  We discuss the prospects of a very long baseline neutrino oscillation
experiment from HIPA to Beijing. The current understanding of neutrino
oscillations, both theoretically and experimentally, are summarized. The figure
of merits for interested physics measurements are defined and compared at
different distances: 300 km, 700 km, 2100 km and 3000 km. We conclude that a
baseline more than 2100 km is optimal. A large water cerenkov calorimeter was
proposed and its performance is satisfactory from a Monte Carlo simulation
study. Such a large detector can do many other measurements on cosmic-rays
physics and astrophysics.


title: Isospin Violation and the Magnetic Moment of the Muon

abstract:
  We calculate the leading isospin-violating and electromagnetic corrections
for the decay tau -> pi^0 pi nu_tau at low energies. The corrections are small
but relevant for the inclusion of tau decay data in the determination of
hadronic vacuum polarization especially for the anomalous magnetic moment of
the muon. We show that part of the systematic differences between the measured
form factors in tau -> pi^0 pi nu_tau and e^+ e^- -> pi^+ pi^- is due to
isospin violation .


title: Higgs: KeV precision and CP violation

abstract:
  The prospects for a muon collider operated as a Higgs factory are reviewed.
The large muon mass means that the s-channel Higgs production mechanism is
available, and simultaneously suppresses bremsstrahlung so that the beam energy
spread can be kept to the MeV level required to exploit this. Thus this is the
only machine which can make a direct scan over the Higgs resonance, and make an
extraordinary mass measurement. Further possibilities such as a scan of the H
and A of supersymmetry and CP violation are also mentioned.


title: Analysis of the first RHIC results in the String Fusion Model

abstract:
  First results from RHIC on charged multiplicities, evolution of
multiplicities with centrality, particle ratios and transverse momentum
distributions in central and minimum bias collisions, are analyzed in a string
model which includes hard collisions, collectivity in the initial state
considered as string fusion, and rescattering of the produced secondaries.
Multiplicities and their evolution with centrality are successfully reproduced.
Transverse momentum distributions in the model show a larger $p_T$-tail than
experimental data, disagreement which grows with increasing centrality.
Discrepancies with particle ratios appear and are examined comparing with
previous features of the model at SPS.


title:
Double chiral logarithms of Generalized Chiral Perturbation Theory for
  low-energy pi-pi scattering

abstract:
  We express the two-massless-flavor Gell-Mann--Oakes--Renner ratio in terms of
low-energy pi-pi observables, including the O(p^6) double chiral logarithms of
generalized chiral perturbation theory. Their contribution is sizeable and
tends to compensate the one from the single chiral logarithms. However it is
not large enough to spoil the convergence of the chiral expansion. As a signal
of reduced theoretical uncertainty, we find that the scale dependence from the
one-loop single logarithms is almost completely canceled by the one from the
two-loop double logarithms.


title:
Evolution of transverse momentum dependent distribution and
  fragmentation functions

abstract:
  We use Lorentz invariance and the QCD equations of motion to study the
evolution of functions that appear at leading order in a 1/Q expansion in
azimuthal asymmetries. This includes the evolution equation of the Collins
fragmentation function. The moments of these functions are matrix elements of
known twist two and twist three operators. We present the evolution in the
large N_c limit, restricting to non-singlet for the chiral-even functions.


title:
Influence of statistical fluctuations on $K/\pi$ ratios in relativistic
  heavy ion collisions

abstract:
  The influence of pure statistical fluctuations on $K/\pi$ ratio is
investigated in an event-by-event way. Poisson and the modified negative
binomial distributions are used as the multiplicity distributions since they
both have statistical background. It is shown that the distributions of the
ratio in these cases are Gaussian, and the mean and relative variance are given
analytically.


title: Geometry of Large Extra Dimensions versus Graviton Emission

abstract:
  We study how the geometry of the large extra dimensions may affect field
theory results on a three-brane. More specifically, we compare cross sections
for graviton emission from a brane when the internal space is a N-torus and a
N-sphere for N=2 to 6. The method we present can be used for other smooth
compact geometries. We find that the ability of high energy colliders to
determine the geometry of the extra dimensions is limited but there is an
enhancement when both the quantum gravity scale and N are large. Our field
theory results are compared with the low energy corrections to the
gravitational inverse square law due to large dimensions compactified on other
spaces such as Calabi-Yau manifolds.


title:
Solving the Hierarchy Problem without Supersymmetry or Extra Dimensions:
  An Alternative Approach

abstract:
  In this paper, we propose a possible new approach towards solving the gauge
hierarchy problem without supersymmetry and without extra spacetime dimensions.
This approach relies on the finiteness of string theory and the conjectured
stability of certain non-supersymmetric string vacua. One crucial ingredient in
this approach is the idea of ``misaligned supersymmetry'', which explains how
string theories may be finite even without exhibiting spacetime supersymmetry.
This approach towards solving the gauge hierarchy problem is therefore
complementary to recent proposals involving both large and small extra
spacetime dimensions. This approach may also give a new perspective towards
simultaneously solving the cosmological constant problem.


title: High Energy Neutrino Signals of Four Neutrino Mixing

abstract:
  We evaluate the upward shower and muon event rates for two characteristic
four neutrino mixing models for extragalactic neutrinos, as well as for the
atmospheric neutrinos, with energy thresholds of 1 TeV, 10 TeV and 100 TeV. We
show that by comparing the shower to muon event rates, one can distinguish
between oscillation and no-oscillation models. By measuring shower and muon
event rates for energy thresholds of 10 TeV and 100 TeV, and by considering
their ratio, it is possible to use extragalactic neutrino sources to determine
the type of four-flavor mixing pattern. We find that one to ten years of data
taking with kilometer-size detector has a very good chance of providing
valuable information about the physics beyond the Standard Model.


title: Some Recent Results from the Generic Supersymmetric Standard Model

abstract:
  The generic supersymmetric standard model is a model built from a
supersymmetrized standard model field spectrum the gauge symmetries only. The
popular minimal supersymmetric standard model differs from the generic version
in having R-parity imposed by hand. We review an efficient formulation of the
model and some of the recently obtained interesting phenomenological features.
The latter includes R-parity violating contributions to scalar masses that had
been largely overlooked and the related contributions to fermion electric
dipole moments and $\mu \to e \gamma$.


title: Resummation of non-global QCD observables

abstract:
  We discuss issues related to the resummation of non-global observables in
QCD, those that are sensitive to radiation in only a part of phase space.
Examples of such observables are certain single-hemisphere event shapes in e+e-
and DIS. Compared to global observables (those sensitive to all emissions, e.g.
the e+e- thrust) a new class of single-logarithmic terms arises. These have
been neglected in recent calculations in the literature. For a whole set of
single hemisphere e+e- and DIS event shapes, we analytically evaluate the first
such term, at order alpha_s^2, and give numerical results for the resummation
of these terms in the large-Nc limit.


title: Kaluza-Klein Theories and the Anomalous Magnetic Moment of the Muon

abstract:
  We discuss nonminimal couplings of fermions to the electromagnetic field,
which generically appear in models with extra dimensions. We consider models
where the electromagnetic field is generated by the Kaluza-Klein mechanism. The
nonminimal couplings contribute at tree-level to anomalous magnetic and
electric dipole moments of fermions. We use recent measurements of these
quantities to put limits on the parameters of models with extra dimensions.


title:
Single Top Production in $e^+ e^-$, $e^- e^-$, $\gamma e$ and $\gamma
  \gamma$ Collisions

abstract:
  Single top quark cross section evaluations for the complete sets of
tree-level diagrams in the $e^+ e^-$, $e^- e^-$, $\gamma e$ and $\gamma \gamma$
modes of the next linear collider with unpolarized and polarized beams are
performed within the Standard Model and beyond. From comparison of all
possibilities we conclude that the process $\gamma_+ e^-_L \to e^- t \bar b$ is
extremely favoured due to large cross section, no $t \bar t$ background, high
degrees of beam polarization, and exceptional sensitivities to $V_{tb}$ and
anomalous $Wtb$ couplings. Similar reasons favour the process $e^- e^- \to e^-
\nu_e \bar t b$ for probing top quark properties despite a considerably lower
cross section. Less favourable are processes like $e^+ e^-, \gamma \gamma \to
e^- \nu_e t \bar b$. Three processes were chosen to probe their sensitivity to
anomalous $Wtb$ couplings, with best bounds found for $\gamma_+ e^-_L \to e^- t
\bar b$ and $e^+_R e^-_R \to e^- \nu_e t \bar b$.


title: Note on the Extraction of |V_{ub}| using Radiative B Decays

abstract:
  The element |V_{ub}| of the quark mixing matrix can be extracted with small
theoretical uncertainties by combining weighted integrals over the endpoint
regions of the lepton spectrum in B -> X_u l nu decays and the photon spectrum
in B -> X_s gamma decays. The perturbative corrections to this determination
are computed at next-to-leading order including operator mixing, which has an
important impact. The effect of Sudakov resummation is shown to be numerically
insignificant.


title: Skyrme model and nonleptonic hyperon decays

abstract:
  This report is an attempt to explain both s- and p-wave nonleptonic hyperon
decays by means of the QCD enhanced effective weak Hamiltonian supplemented by
the SU(3) Skyrme model used to estimate nonperturbative matrix elements. The
model has only one free parameter, namely, the Skyrme charge $e$, which is
fixed through the experimental values of the octet-decuplet mass splitting
$\Delta $ and the axial coupling constant $g_{A}$. Such a dynamical approach
produces nonleptonic hyperon decay amplitudes that agree with experimental data
reasonably well.


title: Phases of QCD with nonvanishing isopin density

abstract:
  The propagation of low-momentum baryons through QCD matter at low isospin
density is studied using chiral perturbation theory. When the isospin chemical
potential exceeds a critical value, the dispersion relation for the lowest
nucleon mode becomes anomalous near zero momentum---increasing momentum yields
decreasing energy---so that the momentum for the lowest energy state, p_min,
becomes nonzero. This can be interpreted as a new phase of QCD, with p_min
serving as the order parameter and the kinetic mass (defined as the inverse of
the second derivative of the energy with respect to the momentum at p_min)
serving as the susceptibility. A lowest-order chiral-perturbation-theory
calculation yields a critical isospin chemical potential of 285 MeV. Since this
is small compared to the chiral-symmetry-breaking scale, corrections to it are
likely to be modest.


title: Transverse Polarisation of Quarks in Hadrons

abstract:
  We review the present state of knowledge regarding the transverse
polarisation (or transversity) distributions of quarks. After some generalities
on transverse polarisation, we formally define the transversity distributions
within the framework of a classification of all leading-twist distribution
functions. We describe the QCD evolution of transversity at leading and
next-to-leading order. A comprehensive treatment of non-perturbative
calculations of transversity distributions (within the framework of quark
models, lattice QCD and QCD sum rules) is presented. The phenomenology of
transversity (in particular, in Drell-Yan processes and semi-inclusive
leptoproduction) is discussed in some detail. Finally, the prospects for future
measurements are outlined.


title:
Analysis of Neutral Higgs-Boson Contributions to the Decays B_s ->
  l^+l^- and B -> K l^+l^-

abstract:
  We report on a calculation of Higgs-boson contributions to the decays B_s ->
l^+l^- and B -> K l^+l^- (l=e, mu) which are governed by the effective
Hamiltonian describing b -> s l^+ l^-. Compact formulae for the Wilson
coefficients are provided in the context of the type-II two-Higgs-doublet model
(2HDM) and supersymmetry (SUSY) with minimal flavour violation, focusing on the
case of large tan(beta). We derive, in a model-independent way, constraints on
Higgs-boson-mediated interactions, using present experimental results on rare B
decays including b -> s gamma, B_s -> mu^+ mu^-, and B -> K^(*) mu^+ mu^-. In
particular, we assess the impact of possible scalar and pseudoscalar
interactions transcending the standard model (SM) on the branching ratio of B_s
-> mu^+ mu^- and the forward-backward (FB) asymmetry of mu^- in B -> K mu^+
mu^- decay. We find that the average FB asymmetry, which is unobservably small
within the SM, and therefore a potentially valuable tool to search for new
physics, is predicted to be no greater than 4% for a nominal branching ratio of
about 6x10^{-7}. Moreover, striking effects on the decay spectrum of B -> K
mu^+ mu^- are already ruled out by experimental data on the B_s -> mu^+ mu^-
branching fraction. In addition, we study the constraints on the parameter
space of the 2HDM and SUSY with minimal flavour violation. While the type-II
2HDM does not give any sizable contributions to the above decay modes, we find
that SUSY contributions obeying the constraint on b -> s gamma can affect
significantly the branching ratio of B_s -> mu^+ mu^-. We also comment on
previous calculations contained in the literature.


title: The Color Glass Condensate and Small x Physics: 4 Lectures

abstract:
  The Color Glass Condensate is a state of high density gluonic matter which
controls the high energy limit of hadronic matter. These lectures begin with a
discussion of general problems of high energy strong interactions. The infinite
momentum frame description of a single hadron at very small x is developed, and
this picture is applied to the description of ultrarelativistic nuclear
collisions. Recent developments in the renormalization group description of the
Color Glass Condensate are reviewed.


title: Higgs Mass in the Standard Model from Coupling Constant Reduction

abstract:
  Plausible interrelations between parameters of the standard model are
studied. The empirical value of the top quark mass, when used in the
renormalization group equations, suggests that the ratio of the colour SU(3)
gauge coupling $g_3$, and the top coupling $g_t$ is independent of the
renormalization scale. On the other hand, variety of top-condensate models
suggest that the Higgs self-coupling $\lambda$ is proportional to $g_t^2$.
Invoking the requirement that the ratio $\lambda(t)/g_t^2(t)$ is independent of
the renormalization scale $t$, fixes the Higgs mass. The pole mass of the Higgs
[which differs from the renormalization group mass by a few percent] is found
to be $\sim 154$ GeV for the one-loop equations and $\sim 148$ GeV for the
two-loop equations.


title:
A note on inequalities for the masses of the lightest pi-pi resonances
  in large N_c QCD

abstract:
  We derive and analyse inequalities relating masses of the lightest pi-pi
resonances (rho and sigma) to low energy couplings of the effective chiral
Lagrangian in the limit of large number of colours.


title: TeV scale unification in four dimensions versus extra dimensions

abstract:
  The gauge coupling constant unification at the low ($O$(TeV)) scale can be
obtained just in four dimensions, without help of the power like
renormalization group evolution in extra dimensions, due to the presence of
some extra particle states at intermediate scales. We show explicit examples of
such extra states in the range of 100 GeV -- 1 TeV which can be easily observed
on future colliders and can have important impact on the particle
phenomenology. The problems of the low scale grand unification and proton
stability are also discussed.


title: Probing the structure of $f_0(980)$ through radiative $\phi$ decays

abstract:
  We consider the radiative transition $\phi \to f_0 \gamma$, which is a
sensitive probe of the nature of the $f_0(980)$ particle. Using the QCD
sum-rule technique, we estimate the branching ratio of such decay mode to be:
${\cal B}(\phi \to f_0 \gamma)=(2.7 \pm 1.1) ~ 10^{-4}$, in fair agreement with
present experimental data. As for the structure of the $f_0$, the result
suggests a sizeable $s {\bar s}$ component; however, this result does not
exclude the possibility of further components and allows a more complex
structure than indicated by the naive quark model.


title: On a QCD-based pion distribution amplitude vs. recent experimental data

abstract:
  Using QCD sum rules with nonlocal condensates the twist-2 pion distribution
amplitude is determined by means of its moments and their confidence intervals,
including also radiative corrections. An admissible set of pion distribution
amplitudes is constructed in the a_2, a_4 plane of the Gegenbauer polynomial
expansion coefficients. The determined a_2, a_4 region strongly overlaps with
that extracted from the CLEO data by Schmedding and Yakovlev. Comparisons are
given with results from Fermilab experiment E791 and recent lattice
calculations.


title: Structure Functions are not Parton Probabilities

abstract:
  The common view that structure functions measured in deep inelastic lepton
scattering are determined by the probability of finding quarks and gluons in
the target is not correct in gauge theory. We show that gluon exchange between
the fast, outgoing partons and target spectators, which is usually assumed to
be an irrelevant gauge artifact, affects the leading twist structure functions
in a profound way. This observation removes the apparent contradiction between
the projectile (eikonal) and target (parton model) views of diffractive and
small x_{Bjorken} phenomena. The diffractive scattering of the fast outgoing
quarks on spectators in the target causes shadowing in the DIS cross section.
Thus the depletion of the nuclear structure functions is not intrinsic to the
wave function of the nucleus, but is a coherent effect arising from the
destructive interference of diffractive channels induced by final state
interactions. This is consistent with the Glauber-Gribov interpretation of
shadowing as a rescattering effect.


title:
Lepton flavor violation in supersymmetric models with non--degenerate
  A-terms

abstract:
  We analyze the lepton-flavor violation in supersymmetric models with
non-universal soft breaking terms derived from strings. We show that the
non-universality of the scalar masses enhances the branching ratios more
significantly than the non-universality of the A-terms


title:
Neutrino oscillations and rare processes in models with a small extra
  dimension

abstract:
  We discuss Dirac neutrino masses and mixings in a scenario where both the
standard model fermions and right handed neutrinos are bulk fields in a
non-factorizable geometry in five dimensions. We show how the atmospheric and
solar neutrino anomalies can be satisfactorily resolved, and in particular how
bimaximal mixing is realized. We also consider rare processes such as
neutron-antineutron oscillations and mu --> e + gamma, which may occur at an
observable rate.


title:
Realization of the Large Mixing Angle Solar Neutrino Solution in an
  SO(10) Supersymmetric Grand Unified Model

abstract:
  An SO(10) supersymmetric grand unified model proposed earlier leading to the
solar solution involving ``just-so'' vacuum oscillations is reexamined to study
its ability to obtain the other possible solar solutions. It is found that all
four viable solar neutrino oscillation solutions can be achieved in the model
simply by modification of the right-handed Majorana neutrino mass matrix, M_R.
Whereas the small mixing and vacuum solutions are easily obtained with several
texture zeros in M_R, the currently-favored large mixing angle solution
requires a nearly geometric hierarchical form for M_R that leads by the seesaw
formula to a light neutrino mass matrix which has two or three texture zeros.
The form of the matrix which provides the ``fine-tuning'' necessary to achieve
the large mixing angle solution can be understood in terms of Froggatt-Nielsen
diagrams for the Dirac and right-handed Majorana neutrino mass matrices. The
solution fulfils several leptogenesis requirements which in turn can be
responsible for the baryon asymmetry in the universe.


title:
Additional ways to determination of structure of high energy elastic
  scattering amplitude

abstract:
  Several methods of extracting the magnitude of the real parts of the elastic
hadron scattering amplitude - from the experimental data are presented. These
methods allows us to obtain the real parts at one definite point of the
transfer momentum and with a high accuracy without knowledge of the precise
values of the normalization coefficient and with minimum theoretical
assumptions.


title: A two-dimensional QCD in the covariant gauge

abstract:
  A nonperturbative approach to 2D covariant gauge QCD is presented in the
context of the Schwinger-Dyson equations for quark and ghost propagators and
the corresponding Slavnov-Taylor identities. The distribution theory,
complemented by the dimensional regularization method, is used in order to
correctly treat the severe infrared singularities which inevitably appear in
the theory. By working out the multiplicative renormalization program we remove
them from the theory on a general ground and in a self-consistent way, proving
thus the infrared multiplicative renormalizability of 2D QCD within our
approach. This makes it possible to sum up the infinite series of the
corresponding planar skeleton diagrams in order to derive a closed set of
equations for the infrared renormalized quark propagator. We have shown that
complications due to ghost degrees of freedom can be considerable within our
approach. It is shown exactly that 2D covariant gauge QCD implies quark
confinement (the quark propagator has no poles, indeed) as well as dynamical
breakdown of chiral symmety (a chiral symmetry preserving solution is
forbidded). We also show explicitly how to formulate the bound-state problem
and the Schwinger-Dyson equations for the gluon propagator and the triple gauge
proper vertex, all free of the severe IR singularities.


title: Quantization of Solitons in Coset Space

abstract:
  The perturbation theory around the soliton fields of the sin-Gordon model is
developed in the coset space. It is shown by explicit calculations that all
corrections to the topological soliton contribution are canceled exactly.


title: Yang-Mills Fields Quantization in the Factor Space

abstract:
  The perturbation theory over inverse interaction constant $1/g$ is
constructed for Yang-Mills theory. It is shown that the new perturbation theory
is free from the gauge ghosts and Gribov's ambiguities, each order over $1/g$
presents the gauge-invariant quantity. It is remarkable that offered
perturbation theory did not contain divergences, at least in the vector fields
sector, and no renormalization procedure is necessary for it.


title:
Black hole physics, confining solutions of SU(3)-Yang-Mills equations
  and relativistic models of mesons

abstract:
  The black hole physics techniques and results are applied to find the set of
the exact solutions of the SU(3)-Yang-Mills equations in Minkowski spacetime in
the Lorentz gauge. All the solutions contain only the Coulomb-like or linear in
$r$ components of SU(3)-connection. This allows one to obtain some possible
exact and approximate solutions of the corresponding Dirac equation that can
describe the relativistic bound states. Possible application to the
relativistic models of mesons is also outlined.


title: Cross Sections and Lorentz Violation

abstract:
  The derivation of cross sections and decay rates in the Lorentz-violating
standard-model extension is discussed. General features of the physics are
described, and some conceptual and calculational issues are addressed. As an
illustrative example, the cross section for the specific process of
electron-positron pair annihilation into two photons is obtained.


title:
Perturbative Stability of the QCD Predictions for Single Spin Asymmetry
  in Heavy Quark Photoproduction

abstract:
  We present the threshold resummation for the single spin asymmetry in heavy
flavor production by linearly polarized photons. We analyze the soft-gluon
contributions to the asymmetry at fixed order in $\alpha_s$ to the
next-to-leading logarithmic accuracy. Our analysis shows that, contrary to the
production cross section, the azimuthal asymmetry is practically insensitive to
soft radiation. Our calculations of the asymmetry up to the 6th order in
$\alpha_s$ lead only to small corrections (of order of few percent) to the Born
predictions at energies of the fixed target experiments. Fast convergence of
the perturbative series for the azimuthal asymmetry is due to the factorization
properties of the photon-hadron cross section. We conclude that measurements of
the single spin asymmetry would provide an excellent test of pQCD applicability
to heavy flavor production.


title: About Superpartners and the Origins of the Supersymmetric Standard Model

abstract:
  We recall the obstacles which seemed, long ago, to prevent supersymmetry from
possibly being a fundamental symmetry of Nature. Which bosons and fermions
could be related? Is spontaneous supersymmetry breaking possible? Where is the
spin-1/2 Goldstone fermion of supersymmetry? Can one define conserved baryon
and lepton numbers in such theories, although they systematically involve
self-conjugate Majorana fermions? etc.. We then recall how an early attempt to
relate the photon with a ``neutrino'' led to the definition of R-invariance,
but that this ``neutrino'' had to be reinterpreted as a new particle, the
photino. This led us to the Supersymmetric Standard Model, involving the SU(3)
x SU(2) x U(1) gauge interactions of chiral quark and lepton superfields, and
of two doublet Higgs superfields responsible for the electroweak breaking and
the generation of quark and lepton masses. The original continuous R-invariance
was then abandoned in favor of its discrete version, R-parity -- reexpressed as
(-1)^2S (-1)^(3B+L) -- so that the gravitino and gluinos can acquire masses. We
also comment about supersymmetry breaking.


title:
Related Power-law Growth of Particle Multiplicities near Midrapidity in
  Central Au+Au Collisions and in $\ol{p}(p)-p$ Collisions

abstract:
  A simple power-law growth of charged-particle multiplicities near midrapidity
in central Au+Au collisions at $\sqrt{s_{NN}}=56$ and 130 GeV, recently
measured at RHIC, is derived. We give predictions for the central particle
densities up to $\sqrt{s_{NN}}=1800$ GeV. A strong growth of the Au+Au
densities above those for $\ol{p}(p)-p$ collisions is predicted.


title:
Hadronic Contributions to the Photon Vacuum Polarization and their Role
  in Precision Physics

abstract:
  I review recent evaluations of the hadronic contribution to the shift in the
fine structure constant and to the anomalous magnetic moment of the muon.
Substantial progress in a precise determination of these important observables
is a consequence of substantially improved total cross section measurement by
the CMD-2 and BES II collaborations and an improved theoretical understanding.
Prospects for further possible progress is discussed.


title: Possible Pseudogap Phase in QCD

abstract:
  Thermal pion fluctuations, in principle, can completely disorder the phase of
the quark condensate and thus restore chiral symmetry. If this happens before
the quark condensate melts, strongly-interacting matter will be in the
pseudogap state just above the chiral phase transition. The quark condensate
does not vanish locally and quarks acquire constituent masses in the pseudogap
phase, despite chiral symmetry is restored.


title: Nonperturbative Effects from the Resummation of Perturbation Theory

abstract:
  Using the general argument in Borel resummation of perturbation theory that
links the divergent perturbation theory to the nonperturbative effect we argue
that the nonperturbative effect associated with the perturbation theory should
have a branch cut only along the positive real axis in the complex coupling
plane. The component in the weak coupling expansion of the nonperturbative
amplitude, which usually includes the leading term in the weak coupling
expansion, that gives rise to the branch cut can be calculated in principle
from the perturbation theory combined with some exactly calculable properties
of the nonperturbative effect. The realization of this mechanism is
demonstrated in the double well potential and the two-dimensional O(N)
nonlinear sigma model. In these models the leading term in weak coupling of the
nonperturbative effect can be obtained with good accuracy from the first terms
of the perturbation theory. Applying this mechanism to the infrared renormalon
induced nonperturbative effect in QCD, we suggest some of the QCD condensate
effects can be calculated in principle from the perturbation theory.


title:
The $S_{11}- N$(1535) and $-N$(1650) Resonances in Meson-Baryon
  Unitarized Coupled Channel Chiral Perturbation Theory

abstract:
  The $s-$wave meson-baryon scattering is analyzed for the strangeness S=0
sector in a Bethe-Salpeter coupled channel formalism incorporating Chiral
Symmetry. Four channels have been considered: $\pi N$, $\eta N$, $K \Lambda$,
$K \Sigma$. The needed two particle irreducible matrix amplitude is taken from
lowest order Chiral Perturbation Theory in a relativistic formalism and low
energy constants are fitted to the elastic $\pi N $ phase-shifts and the $\pi^-
p \to \eta n$ and $\pi^- p \to K^0 \Lambda$ cross section data. The position of
the complex poles in the second Riemann sheet of the scattering amplitude
determine masses and widths of the $S_{11}-$ $N$(1535) and $-N$(1650)
resonances, in reasonable agreement with experiment. A good overall description
of data, from $\pi N$ threshold up to 2 GeV, is achieved keeping in mind that
the two pion production channel has not been included.


title: Detecting top-Higgs at high energy $e^{+}e^{-}$ colliders

abstract:
  We calculate the contributions of the top-Higgs $h_{t}^{0}$ predicted by
topcolor assisted technicolor(TC2) models to $e^{+}e^{-}\longrightarrow
\overline{t}c\overline{\nu}_{e}\nu_{e}$ and compare the results with the
contributions of $h^{0}_{t}$ to the processes $e^{+}e^{-}\longrightarrow Z
h^{0}_{t}\longrightarrow Z\overline{t}c$ and $e^+e^-\longrightarrow \gamma
h^{0}_{t} \longrightarrow \gamma \overline{t}c$. We find that $e^{+}e^{-}
\longrightarrow\overline{t}c\overline{\nu}_{e}\nu_{e}$ is very sensitive to
$h^{0}_{t}$, which can be easy detected via this process at high-energy
$e^{+}e^{-}$ collider(LC) experiments with $\sqrt{s}\geq 500$ $GeV$, as long as
its mass below the $\overline{t}t$ threshold. The process $e^{+}e^{-}
\longrightarrow \gamma\overline{t}c$ also can be used to detect $h^{0}_{t}$ at
LC experiments.


title: Double J/\psi Production at Photon Colliders

abstract:
  The double J/\psi(DJ) production in direct photon-photon collision is
investigated. It is found that the J/\psi production rate in this process is of
the same order of magnitude as those of previously discussed ones, which hints
the dominant J/\psi inclusive production process in the direct photon-photon
collision is still not being touched. As DJ production process has a clear
distinction from the single J/\psi inclusive processes in the final states,
experimental study on it would be helpful to clarify the validity of
color-singlet model.


title: Electroweak Sudakov effect on processes at TeV scale

abstract:
  In Next Linear Colliders at TeV scale, electroweak double logarithmic
corrections, which come from the infrared behaviors of theory can not be
neglected. It is well known that in QED and QCD, double logarithmic corrections
are resummed to all orders, and these corrections can be exponentiated,
resulting in the Sudakov form factor. However it is never trivial that double
logarithmic corrections in electroweak theory can be exponentiated, because of
the spontaneous breaking of symmetry and the pattern of that. We discuss the
electroweak double logarithmic corrections at two loop level and explain the
differences of ``Soft'' structure between the electroweak theory and QCD (the
unbroken non-abelian gauge theory).


title:
The explanation of unexpected temperature dependence of the muon
  catalysis in solid deuterium

abstract:
  It is shown that due to the smallness of the inelastic cross-section of the
$d\mu$-atoms scattering in the crystal lattice at sufficiently low temperatures
the $dd\mu$-mesomolecules formation from the upper state of the hyperfine
structure $d\mu (F=3/2)$ starts earlier than the mesoatoms thermolization. It
explains an approximate constancy of the $dd\mu$-mesomolecule formation rate in
solid deuterium.


title: Neutrino Masses and Lepton Flavour Violation in Thick Brane Scenarios

abstract:
  We address the issue of lepton flavour violation and neutrino masses in the
``fat-brane'' paradigm, where flavour changing processes are suppressed by
localising different fermion field wave-functions at different positions (in
the extra dimensions) in a thick brane. We study the consequences of
suppressing lepton number violating charged lepton decays within this scenario
for lepton masses and mixing angles. In particular, we find that charged lepton
mass matrices are constrained to be quasi-diagonal. We further consider whether
the same paradigm can be used to naturally explain small Dirac neutrino masses
by considering the existence of three right-handed neutrinos in the brane, and
discuss the requirements to obtain phenomenologically viable neutrino masses
and mixing angles. Finally, we examine models where neutrinos obtain a small
Majorana mass by breaking lepton number in a far away brane and show that, if
the fat-brane paradigm is the solution to the absence of lepton number
violating charged lepton decays, such models predict, in the absence of flavour
symmetries, that charged lepton flavour violation will be observed in the next
round of rare muon/tau decay experiments.


title: Understanding $K/\pi$ ratio distribution in the mixed events

abstract:
  The event mixing method is analyzed for the study of the event-by-event
$K/\pi$ ratio distribution. It is shown that there exists some correlation
between the kaon and pion multiplicities in the mixed events. The $K/\pi$ ratio
distributions in the mixed events for different sets of real events are shown.
The dependence of the distributions on the mean $K/\pi$ ratio, mean and
variance of multiplicity distribution in the real events is investigated
systematically. The effect of imperfect particle identification on the $K/\pi$
ratio distribution in the mixed event is also considered.


title: Event weights for simulating Bose-Einstein correlations

abstract:
  An event weighting method for simulating Bose-Einstein effects in hadronic
final states is presented. The weight for an event depends on the momentum
distribution of identical bosons in the event. By using a theoretically
motivated parametrisation allowing weights below as well as above unity, the
necessity of a weight-rescaling procedure is eliminated. A single parameter is
used to adjust the average event weight to unity. Once adjusted, the same value
of the parameter gives average event weights that are essentially independent
of energy, initial quark flavour, multiplicity and jet topology. The influence
of Bose-Estein correlations on various measurable quantities in W pair
production is found to be small. In particular, none of the scenarios
considered resulted in a W mass shift larger than 20 MeV.


title:
Multi-jet cross sections in deep inelastic scattering at next-to-leading
  order

abstract:
  We present the perturbative prediction for three-jet production cross section
in DIS at the NLO accuracy. We study the dependence on the renormalization and
factorization scales of exclusive three-jet cross section. The perturbative
prediction for the three-jet differential distribution as a function of the
momentum transfer is compared to the corresponding data obtained by the H1
collaboration at HERA.


title:
Ambiguity in source flux of high-energy cosmic/astrophysical neutrinos:
  Effects of bi-maximal mixing and quantum-gravity induced decoherence

abstract:
  For high energy cosmic neutrinos Athar, Jezabek, and Yasuda (AJY) have
recently shown that the existing data on neutrino oscillations suggests that
cosmic neutrino flux at the AGN/GRB source, F(nu_e):F(nu_mu):F(nu_tau) approx
1:2:0, oscillates to F(nu_e):F(nu_mu):F(nu_tau) approx 1:1:1. These results can
be confirmed at AMANDA, Baikal, ANTARES and NESTOR, and other neutrino
detectors with a good flavor resolution. Here, we re-derive the AJY result from
quasi bi-maximal mixing, and show that observation of
F(nu_e):F(nu_mu):F(nu_tau) approx 1:1:1 does not necessarily establish cosmic
neutrino flux at the AGN/GRB source to be F(nu_e):F(nu_mu):F(nu_tau) approx
1:2:0. We also note that if the length scale for the quantum-gravity induced
de-coherence for astrophysical neutrinos is of the order of a Mpc, then
independent of the MNS matrix, the Liu-Hu-Ge (LHG) mechanism would lead to flux
equalization for the cosmic/astrophysical neutrinos.


title:
Constraints on lepton flavor violation in the MSSM from the muon
  anomalous magnetic moment measurement

abstract:
  We establish a correspondence between those Feynman diagrams in the MSSM
which give supersymmetric contributions to the muon anomalous magnetic moment
and those which contribute to the flavor violating processes $\mu --> e\gamma$
and $\tau --> \mu\gamma$. Using current experimental limits on the branching
ratios of these decay modes, combined with the assumption of a supersymmetric
contribution to the muon anomalous magnetic moment, we establish bounds on the
size of the lepton flavor violating soft masses in the MSSM largely independent
of assumptions about other supersymmetric parameters. If the deviation measured
at Brookhaven National Laboratory is from supersymmetry, we find the bounds
${m^2}_{e \mu}/ {{\bar{m}}^2} \lsim 2 \times 10^{-4}$ and ${m^2}_{\tau \mu}/
{{\bar{m}}^2} \lsim 1 \times 10^{-1}$, where ${\bar{m}}^2$ is the mass of the
heaviest particle in any loop that contributes at this level to the anomalous
magnetic moment of the muon. This provides a significant constraint on the
non-flavor-blind mediation of supersymmetry breaking that often occurs at a
suppressed level in many models, including gaugino mediation.


title:
Density Fluctuations and Primordial Black Hole Formation in Natural
  Double Inflation in Supergravity

abstract:
  We investigate the recently proposed natural double inflation model in
supergravity. Chaotic inflation first takes place by virtue of the
Nambu-Goldstone-like shift symmetry. During chaotic inflation, an initial value
of second inflation (new inflation) is set, which is adequately far from the
local maximum of the potential due to the small linear term in the K\"ahler
potential. Then, primordial fluctuations within the present horizon scale may
be produced during both inflations. Primordial fluctuations responsible for
anisotropies of the cosmic microwave background radiation and the large scale
structure are produced during chaotic inflation, while fluctuations on smaller
scales are produced during new inflation. Because of the peculiar nature of new
inflation, they can become as large as $10^{-1}$-$10^{-2}$, which may lead to
the formation of primordial black holes.


title: TeV-scale electron Compton scattering in the Randall-Sundrum scenario

abstract:
  The spin-2 graviton excitations in the Randall-Sundrum gravity model provides
a t-channel contribution to electron Compton scattering which competes
favourably with the standard QED contributions. The phenomenological
implications of these contributions to the unpolarized and polarized
cross-sections are evaluated.


title: Leading-power contributions to $B\to\pi,\rho$ transition form factors

abstract:
  We calculate the $B\to\pi,\rho$ transition form factors in the framework of
perturbative QCD to leading power of $1/M_B$, $M_B$ being the $B$ meson mass.
We explain the basic principle by discussing the pion electromagnetic form
factor. It is shown that the logarithmic and linear singularities occurring at
small momentum fractions of light meson distribution amplitudes do not exist in
a self-consistent perturbative analysis, which includes $k_\perp$ and threshold
resummations.


title: How Finely Tuned is Supersymmetric Dark Matter?

abstract:
  We introduce a quantification of the question in the title: the logarithmic
sensitivity of the relic neutralino density Omega-hsquared to variations in
input parameters such as the supersymmetric mass scales m_0, m_1/2 and A_0, tan
beta and the top and bottom quark masses. In generic domains of the CMSSM
parameter space with a relic density in the preferred range 0.1 <
Omega-hsquared < 0.3, the sensitivities to all these parameters are moderate,
so an interesting amount of supersymetric dark matter is a natural and robust
prediction. Within these domains, the accuracy in measuring the CMSSM and other
input parameters at the LHC may enable the relic density to be predicted quite
precisely. However, in the coannihilation regions, this might require more
information on the supersymetric spectrum than the LHC is able to provide.
There are also exceptional domains, such as those where direct-channel pole
annihilation dominates, and in the `focus-point' region, where the logarithmic
sensitivity to the input parameters is greatly increased, and it would be more
difficult to predict Omega-hsquared accurately.


title:
Muon Anomalous Magnetic Moment and $\tau \to \mu \gamma$ in a Realistic
  String-Inspired Model of Neutrino Masses

abstract:
  We discuss the lepton sector of a realistic string-inspired model based on
the Pati-Salam $SU(4)\times SU(2)_L \times SU(2)_R$ gauge group supplemented by
a U(1) family symmetry. The model involves third family Yukawa unification,
predicts large $\tan \beta\sim 50$, and describes all fermion masses and mixing
angles, including approximate bi-maximal mixing in the neutrino sector.
Atmospheric neutrino mixing is achieved via a large 23 entry in the neutrino
Yukawa matrix which can have important phenomenological effects. We find that
the recent BNL result on the muon ($g-2$) can be easily accommodated in a large
portion of the SUSY parameter space of this model. Over this region of
parameter space the model predicts a CP-even Higgs mass near 115 GeV, and a
rate for $\tau\to \mu\gamma$ which is close to its current experimental limit.


title:
K_L -> pi0 gamma gamma and the bound on the CP-conserving K_L -> pi0
  e+e-

abstract:
  It has been known for many years that there is a CP-conserving component for
the decay mode K_L -> pi0 e+e- and that its magnitude can be obtained from a
measurement of the amplitudes in the K_L -> pi0 gamma gamma decay mode. We
point out that the usual description of the latter in terms of a single
parameter, a_V, is not sufficient to extract the former in a model independent
manner. We further show that there exist known physics contributions to K_L ->
pi0 gamma gamma that cannot be described in terms of the single parameter a_V.
We conclude that a model independent analysis requires the experimental
extraction of three parameters.


title:
Chiral Superconducting Strings and Nambu-Goto Strings in Arbitrary
  Dimensions

abstract:
  We present general solutions to the equations of motion for a superconducting
relativistic chiral string that satisfy the unit magnitude constraint in terms
of products of rotations. From this result we show how to construct a general
family of odd harmonic superconducting chiral loops. We further generalise the
product of rotations to an arbitrary number of dimensions.


title: Determination of the bottom quark mass from the $\Upsilon(1S)$ system

abstract:
  We approximately compute the normalization constant of the first infrared
renormalon of the pole mass (and the singlet static potential). Estimates of
higher order terms in the perturbative relation between the pole mass and the
$\MS$ mass (and in the relation between the singlet static potential and
$\alpha_s$) are given. We define a matching scheme (the renormalon subtracted
scheme) between QCD and any effective field theory with heavy quarks where,
besides the usual perturbative matching, the first renormalon in the Borel
plane of the pole mass is subtracted. A determination of the bottom $\MS$ quark
mass from the $\Upsilon(1S)$ system is performed with this new scheme and the
errors studied. Our result reads $m_{b,\MS}(m_{b,\MS})=4 210^{+90}_{-90}({\rm
theory})^{-25}_{+25}(\alpha_s)$ MeV. Using the mass difference between the $B$
and $D$ meson, we also obtain a value for the charm quark mass:
$m_{c,\MS}(m_{c,\MS})=1 210^{+70}_{-70}({\rm
theory})^{+65}_{-65}(m_{b,\MS})^{-45}_{+45}(\lambda_1)$ MeV. We finally discuss
upon eventual improvements of these determinations.


title: The Minimal CFL-Nuclear Interface

abstract:
  At nuclear matter density, electrically neutral strongly interacting matter
in weak equilibrium is made of neutrons, protons and electrons. At sufficiently
high density, such matter is made of up, down and strange quarks in the
color-flavor locked phase, with no electrons. As a function of increasing
density (or, perhaps, increasing depth in a compact star) other phases may
intervene between these two phases which are guaranteed to be present. The
simplest possibility, however, is a single first order phase transition between
CFL and nuclear matter. Such a transition, in space, could take place either
through a mixed phase region or at a single sharp interface with electron-free
CFL and electron-rich nuclear matter in stable contact. Here we construct a
model for such an interface. It is characterized by a region of separated
charge, similar to an inversion layer at a metal-insulator boundary. On the CFL
side, the charged boundary layer is dominated by a condensate of negative
kaons. We then consider the energetics of the mixed phase alternative. We find
that the mixed phase will occur only if the nuclear-CFL surface tension is
significantly smaller than dimensional analysis would indicate.


title: From a Thick to a Thin Supergravity Domain Wall

abstract:
  Within D=4 N=1 supergravity theory we obtain an effective theory of the thin
wall limit for a flat domain wall configuration, interpolating between isolated
supersymmetric extrema of the matter potential. We focus on the Z_2 symmetric
flat wall and derive the supersymmetric effective action both in the bulk and
on the wall; in the thin wall limit the scalar field, forming the wall, is
frozen, and provides the delta function domain wall source, while its fermionic
partner decouples due to its large mass. In addition, the interaction between
the gravitational supermultiplet and the interaction of the matter multiplet
decouples on the wall. While the results are explicitly demonstrated within N=1
D=4 supergravity, we also provide a generalization of the result to
D-dimensions.


title: The Standard Model Prediction for epsilon'/epsilon

abstract:
  We present a detailed analysis of epsilon'/epsilon within the Standard Model,
taking into account the strong enhancement through final-state interactions
identified in refs. [1] and [2]. The relevant hadronic matrix elements are
fixed at leading order in the 1/N_C expansion, through a matching procedure
between the effective short-distance Lagrangian and its corresponding
low-energy description in Chiral Perturbation Theory. All large logarithms are
summed up, both at short and long distances. Two different numerical analyses
are performed, using either the experimental or the theoretical value for
epsilon, with compatible results. We obtain Re(epsilon'/epsilon) = (1.7 +-
0.9)*10^{-3}. The error is dominated by the uncertainty in the value of the
strange quark mass and the estimated corrections from unknown 1/N_C-suppressed
local contributions. A better estimate of the strange quark mass would reduce
the uncertainty to about 30%. The Standard Model prediction agrees with the
present experimental world average Re(epsilon'/epsilon) =(1.93 +-
0.24)*10^{-3}.


title: Analysis of direct CP violation in $B^- \to D^0 D_s^-, D^0 D^-$ decays

abstract:
  We investigate the possibility of observing the direct CP violation in the
decay modes $B^- \to D^0 D_s^-$ and $D^0 D^-$ within the Standard Model.
Including the contributions arising from the tree, annihilation, QCD as well as
electroweak penguins with both time- and space-like components, we find that
the direct CP asymmetry in $B^- \to D^0 D_s^-$ is very small $\sim 0.2$ % but
in $B^- \to D^0 D^- $ decay it can be as large as 4%. Approximately $10^7$
charged $B$ mesons are required to experimentally observe the CP asymmetry
parameter for the later case. Since this is easily accessible with the
currently running B factories, the decay mode $B^- \to D^0 D^-$ may be pursued
to look for CP violation.


title:
Lattice spacing dependence of phase transition temperature in the
  classical linear sigma model

abstract:
  We have investigated the phase transition properties of classical linear
sigma model. The fields were kept in contact with a heat bath for sufficiently
long time such that fields are equilibrated at the temperature of the heat
bath. It was shown that the sigma model fields undergoes phase transition, but
the transition temperature depend crucially on the lattice spacing. In the
continuum limit, the transition temperature tends to zero or at least to a very
low value.


title: A Light Higgs Boson Explanation for the g-2 Crisis

abstract:
  A light CP-even Higgs boson with a mass of around 10 GeV could explain the
recent BNL measurement of the muon anomalous magnetic moment. This observation
is based on a general CP-conserving two Higgs doublet extension of the Standard
Model with no tree-level flavor changing neutral current couplings. The Higgs
mass is constrained by experiments at CESR and LEP to be less than twice the
lightest B-meson mass and greater than (roughly) the Upsilon mass. It may be
possible to exclude or discover such a Higgs boson by fully analyzing the
existing LEP data.


title: Power Corrections in Flavour-Singlet Deep Inelastic Scattering

abstract:
  We investigate the 1/Q^2 power-suppressed corrections to structure functions
in the flavour-singlet channel of deep inelastic lepton scattering arising from
renormalon insertions into an initial-state gluon, as obtained using the
dispersive approach. The pinch technique is used as a convenient tool in the
separation of contributions.


title:
A consistent treatment for pion form factors in space-like and time-like
  regions

abstract:
  We write down some relevant matrix elements for the scattering and decay
processes of the pion by considering a quark-meson vertex function. The pion
charge and transition form factors $F_\pi$, $F_{\pi\gamma}$, and
$F_{\pi\gamma^*}$ are extracted from these matrix elements using a relativistic
quark model on the light-front. We found that, the form factors $F_\pi$ and
$F_{\pi\gamma}$ in the space-like region agree well with experiment.
Furthermore, the branching ratios of all observed decay modes of the neutral
pion, that are related to the form factors $F_{\pi\gamma}$ and
$F_{\pi\gamma^*}$ in the time-like region, are all consistent with the data as
well. Additionally, $F_\pi$ in the time-like region, which deals with the
nonvalence contribution, is also discussed.


title: Difficulties in Obtaining Weak Phases from $b\to d$ Penguin Decays

abstract:
  We re-examine a recent proposal for obtaining \beta using the measurements of
the b -> d penguin decays B_d(t) -> K^0 \kbar and B_s(t) -> \phi K_S, along
with a theoretical assumption. We show that there are in fact three assumptions
one can make, so that the method can in principle be used to extract \alpha,
\beta or \gamma. We also show that it is the assumption which yields \gamma
which is the best. However, the theoretical error on this assumption is still
25-30%, which leads to an error on \gamma of at least 20-25%. Given our current
understanding of hadronic physics, it does not seem possible to reduce this
error.


title: Light Higgs bosons from a strongly interacting Higgs sector

abstract:
  The mass and the decay width of a Higgs boson in the minimal standard model
are evaluated by a variational method in the limit of strong self-coupling
interaction. The non-perturbative technique provides an interpolation scheme
between strong-coupling regime and weak-coupling limit where the standard
perturbative results are recovered. In the strong-coupling limit the physical
mass and the decay width of the Higgs boson are found to be very small as a
consequence of mass renormalization. Thus it is argued that the eventual
detection of a light Higgs boson would not rule out the existence of a strongly
interacting Higgs sector.


title: Lorentz Group in Feynman's World

abstract:
  R. P. Feynman was quite fond of inventing new physics. It is shown that some
of his physical ideas can be supported by the mathematical instruments
available from the Lorentz group. As a consequence, it is possible to construct
a Lorentz-covariant picture of the parton model. It is shown first how the
Lorentz group can be used for studying the internal space-time symmetries of
relativistic particles. These symmetries are dictated by Wigner's little
groups, whose transformations leave the energy-momentum four-vector of a given
particle invariant. The symmetry of massive particles is like the
three-dimensional rotation group, while the symmetry of massless particles is
locally isomorphic to the two-dimensional Euclidean group. It is noted that the
E(2)-like symmetry of massless particles can be obtained as an
infinite-momentum and/or zero-mass limit of the O(3)-like little group for
massive particles. It is shown that the formalism can be extended to cover
relativistic particles with space-time extensions, such as heavy ions and
hadrons in the quark model. It is possible to construct representations of the
little group using harmonic oscillators, which Feynman et al. used for studying
relativistic extended hadrons. This oscillator formalism allows us to show that
Feynman's parton model is a Lorentz-boosted quark model. The formalism also
allows us to explain in detail Feynman's rest of the universe which is
contained in his parton picture.

categories: hep-ph hep-th math-ph math.MP nucl-th quant-ph


title: Strangeness Suppression in Proton-Proton Collisions

abstract:
  We analyse strangeness production in proton-proton (pp) collisions at SPS and
RHIC energies, using the recently advanced NeXus approach. After having
verified that the model reproduces well the existing data, we interpret the
results: strangeness is suppressed in proton-proton collisions at SPS energy as
compared to electron-positron (e+e-) annihilation due to the limited masses of
the strings produced in the reaction, whereas high energy pp and e+e-
collisions agree quantitatively . Thus strangeness suppression at SPS energies
is a consequence of the limited phase-space available in string fragmentation.


title:
Casimir Energy and Radius Stabilization in Five and Six Dimensional
  Orbifolds

abstract:
  We compute the one-loop Casimir energy of gravity and matter fields, obeying
various boundary conditions, in 5-dimensional S^1/Z_2 and 6-dimensional T^2/Z_k
orbifolds. We discuss the role of the Casimir energy in possible radius
stabilization mechanisms and show that the presence of massive as well as
massless fields can lead to minima with zero cosmological constant. In the 5-d
orbifold, we also consider the case where kinetic terms localized at the fixed
points are not small. We take into account their contribution to the Casimir
energy and show that localized kinetic terms can also provide a mechanism for
radius stabilization. We apply our results to a recently proposed 5-dimensional
supersymmetric model of electroweak symmetry breaking and show that the Casimir
energy with the minimal matter content is repulsive. Stabilizing the radius
with zero cosmological constant requires, in this context, adding positive bulk
cosmological constant and negative brane-tension counterterms.


title:
Dependence of the Chiral Symmetry Restoration Transition on the Quark
  Self-Energy Kernel

abstract:
  The dependence of the dressed quark propagator on the quark chemical
potential is investigated in various models based on the Dyson-Schwinger
equations. We find that the critical chemical potential of the chiral symmetry
restoration transition is strongly dependent on the nature of the interaction
kernel in the infrared region.


title: QCD Sum Rule for Heavy Baryons

abstract:
  We construct the heavy baryonic currents by using the Bethe-Salpeter wave
functions in the heavy quark limit. We discuss the one-loop renormalization of
these heavy baryonic currents as well as their two-point correlators up to the
order $1/M_h$. For a special case, we do the QCD sum rule for masses of the
doublet (3/2,5/2).


title: Chiral Transition and the Scalar and Vector Correlations

abstract:
  The properties of the scalar and vector correlations in the hot and/or dense
hadronic matter close to chiral transition are discussed. Presuming that the
linear realization of chiral symmetry will become appropriate at least near the
critical point, we argue that the strength function in the $I=J=0$ channel will
soften near the critical point, and the sigma meson will accordingly become a
clearer resonance in hot and/or dense medium than in the free space. It is
shown that the steep rise of the baryon-number susceptibility $\chi_B$ around
the critical point seen in the lattice simulations may suggest that the
interactions between quarks in the vector channel become week near the critical
point; this implies that the peculiar behavior of the $\chi_B$ does not
necessarily imply a proliferation of baryons and antibaryons (Skyrmions) which
is though a natural scenario of chiral transition in the non-linear realization
of chiral symmetry.


title:
Slepton Flavor Nonuniversality, the Muon EDM and its Proposed sensitive
  Search at Brookhaven

abstract:
  We analyze the electric dipole moment of the electron ($d_e$), of the neutron
($d_n$) and of the muon ($d_{\mu}$) using the cancellation mechanism in the
presence of nonuniversalities of the soft breaking parameters. It is shown that
the nonuniversalities in the slepton sector produce a strong violation of the
scaling relation $d_{\mu}/d_e\simeq m_{\mu}/m_e$ in the cancellation region. An
analysis of $d_e, d_n$ and $d_{\mu}$ under the constraints of the current
experimental limits on $d_e$ and $d_n$ and under the constraints of the recent
Brookhaven result on $g_{\mu}-2$ shows that in the non-scaling region $d_{\mu}$
can be as large as ($10^{-24}-10^{-23}$)ecm and thus within reach of the
recently proposed Brookhaven experiment for a sensitive search for $d_{\mu}$ at
the level of $10^{-24}$ ecm.


title: Higgs and Supersymmetry searches at the Large Hadron Collider

abstract:
  We present here the results for Higgs and Supersymmetry prospective searches
at the Large Hadron Collider. We show that for one year at high luminosity,
Standard Model and MSSM Higgs should be observed within the theoretically
expected mass range. MSUGRA and restricted phenomenological MSSM searches lead
to discovery of up to 2.5 TeV squarks and gluinos.


title:
Exotic Solutions to the Solar Neutrino Problem and Some Implications for
  Low Energy Solar Neutrino Experiments

abstract:
  In this talk, I review, from the phenomenological point of view, solutions to
the solar neutrino problem, which are not provided by the conventional neutrino
oscillation induced by mass and flavor mixing, and show that they can provide a
good fit to the observed data. I also consider some simple implications for low
energy solar neutrino experiments.


title: Gluino-squark contributions to CP violations in the kaon system

abstract:
  Recently it was shown, within the mass insertion approximation (MIA), that
the gluino mediated flavor changing neutral current (FCNC) interactions can
saturate both epsilon_K and Re(epsilon'/epsilon_K) even for the real
Cabibbo-Kobayashi-Maskawa (CKM) matrix through a single CP violating parameter
(delta^d_12)_LL. In this work, we extend our previous analysis to the
nonvanishing KM phase, and to the effective SUSY model where the MIA is no
longer a good approximation. In our model, epsilon_K and B0 - B0 bar mixing can
receive significant SUSY contributions. Therefore the usual constraints on rho
and eta in the Wolfenstein parametrization of the CKM matrix can be relaxed
except for the |V_ub/V_cb| from the semileptonic b -> u transition. This
affects K -> pi nu nu bar and K_L -> mu+ mu- indirectly, even if they are not
directly induced by gluino-mediated FCNC, while K_L -> pi0 e+ e- is influenced
both directly and indirectly. Differences between our model and other SUSY
models enhancing Re(epsilon'/epsilon_K) are discussed in detail.


title: T violation in neutrino oscillations in matter

abstract:
  We consider the interplay of fundamental and matter-induced T violation
effects in neutrino oscillations in matter. After discussing the general
features of these effects we derive a simple approximate analytic expression
for the T-violating probability asymmetry \Delta P^T_{ab} for three-flavour
neutrino oscillations in a matter with an arbitrary density profile in terms of
the two-flavour neutrino amplitudes. Explicit examples are given for the cases
of a two-layer medium and for the adiabatic limit in the general case. We then
discuss implications of the obtained results for long baseline experiments. We
show, in particular, that asymmetric matter effects cannot hinder the
determination of the fundamental CP and T-violating phase \delta_{CP} in the
long baseline experiments as far as the error in this determination is larger
than 1% at 99% C.L. Since there are no T-violating effects in the two-flavour
case, and in the limits of vanishing \theta_{13} or \Delta m_{21}^2 the
three-flavour neutrino oscillations effectively reduce to the two-flavour ones,
studying the T-violating asymmetries \Delta P^T_{ab} can in principle provide
us with a complementary means of measuring \theta_{13} and \Delta m_{21}^2.


title: Unified QCD picture of hard diffraction

abstract:
  Using a combination of S-Matrix and perturbative QCD properties in the small
x_{Bjorken} regime, we propose a formulation of hard diffraction unifying the
partonic (Ingelman-Schlein) Pomeron, Soft Colour Interaction and QCD dipole
descriptions. In particular, we show that all three approaches give an unique
and mutually compatible formula for the proton diffractive structure functions
incorporating perturbative and non perturbative QCD features.


title: Supersymmetry Without Universality: CP Violation and Mixing in B Mesons

abstract:
  We study flavour physics and CP violation in the context of low energy
Supersymmetry with non-universal soft mass terms for sfermions. Large
deviations from Standard Model predictions are allowed in B-physics, as shown
in two explicit examples. In particular, the consequences of these models for
a_(J/\psi K) and Delta m_(B_s) are worked out.


title: Radiative Corrections to Polarized Inelastic Scattering in Coincidence

abstract:
  The coplete analysis of the model-independent leading radiative corrections
to cross-section and polarization observables in semi-inclusive deep-inelastic
electron-nucleus scattering with detection of a proton and scattered electron
in coincidence has been performed. The basis of the calculations consists of
the Drell-Yan like representation in electrodynamics for both spin-independent
and spin-dependent parts of the cross-section in terms of the electron
structure functions. The applications to the polarization transfer effect from
longitudinally polarized electron beam to detected proton as well as to
scattering by the polarized target are considered.


title: Threshold eta and eta' electroproduction off nucleons

abstract:
  The electroproduction of eta and eta' mesons on the proton and the neutron is
investigated at tree level within the framework of U(3) chiral perturbation
theory. In addition to the Born terms low-lying resonances such as the vector
mesons and J^P= 1/2^+, 1/2^- baryon resonances are included explicitly and
their contributions are calculated. Results for the separated differential
cross sections are presented.


title: Positronium Decay : Gauge Invariance and Analyticity

abstract:
  The construction of positronium decay amplitudes is handled through the use
of dispersion relations. In this way, emphasis is put on basic QED principles:
gauge invariance and soft-photon limits (analyticity).
  A firm grounding is given to the factorization approaches, and some
ambiguities in the spin and energy structures of the positronium wavefunction
are removed. Non-factorizable amplitudes are naturally introduced. Their
dynamics is described, especially regarding the enforcement of gauge invariance
and analyticity through delicate interferences. The important question of the
completeness of the present theoretical predictions for the decay rates is then
addressed. Indeed, some of those non-factorizable contributions are unaccounted
for by NRQED analyses. However, it is shown that such new contributions are
highly suppressed, being of order alpha^3.
  Finally, a particular effective form factor formalism is constructed for
parapositronium, allowing a thorough analysis of binding energy effects and
analyticity implementation.


title: Effective Beta-Functions for Effective Field Theory

abstract:
  We consider the problem of determining the beta-functions for any reduced
effective field theory. Even though not all the Green's functions of a reduced
effective field theory are renormalizable, unlike the full effective field
theory, certain effective beta- functions for the reduced set of couplings may
be calculated without having to introduce vertices in the Feynman rules for
redundant operators. These effective beta-functions suffice to apply the
renormalization group equation to any transition amplitude (i.e., S- matrix
element), thereby rendering reduced effective field theories no more cumbersome
than traditionally renormalizable field theories. These effective
beta-functions may equally be regarded as the running of couplings for a
particular redefinition of the fields.


title: What heavy quanta bounds could be inferred from a Higgs discovery?

abstract:
  The Higgs couplings can receive non-decoupling corrections due to heavy
quanta, and deviations from the SM can be used to test its presence. The
possible Higgs signal recently reported at LEP, with mh=115 GeV, severely
constrains the presence of heavy quanta, such as a heavy fourth family. At
Tevatron, the Higgs production by gluon fusion, followed by the decay h -> WW*,
can also be used to probe the existence of heavy colored particles, including
additional families, chiral sextet and octet quarks. Within the MSSM, we also
find that gluon fusion is a sensitive probe for the squark spectrum.


title:
Supersymmetric contributions to muon g-2 and the electroweak precision
  measurements

abstract:
  In view of the recent measurement of the muon g-2 and finalization of the LEP
electroweak data, we re-examine all the new particle contributions to those
observables in the MSSM. The SM fits the latest electroweak data excellently
with the observed top-quark mass and the Higgs-boson mass of around 100 GeV,
and so does the MSSM in the decoupling limit. The MSSM gives a slightly better
fit to the data than the SM (\Delta \chi^2_{min} \sim -2) when relatively light
left-handed sleptons of mass \sim 200 GeV and a light chargino of mixed
higgsino-wino character (\mu/M_2 \sim 1) with mass \sim 100 GeV co-exist. The
improvement in the fit diminishes quickly for wino- or higgsino- dominant
charginos, for heavier charginos, and for lighter sleptons. We find that the
MSSM contributions to the muon g-2 is most efficient when the light chargino
has a mixed character. If \tan\beta < 10, the set of a light mixed chargino and
light sleptons that is favored by the electroweak data is also favored by the
g-2 data for \mu >0. Models with light gauginos (\mu/M_2 > 10) or light
higgsinos (\mu/M_2 < 0.1) give significant contributions to muon g-2 only for
large \tan\beta (\simgt 15).


title: Anomalous dimension of non-singlet quark currents at O(1/Nf^2) in QCD

abstract:
  We compute the O(1/Nf^2) corrections to the flavour non-singlet quark
bilinear currents in QCD in arbitrary spacetime dimensions. Hence, the
anomalous dimension of the QED current $\bar{\psi} \sigma^{\mu\nu} \psi$ is
deduced at four loops in the MSbar scheme up to one unknown parameter.


title: Azimuthal decorrelation of forward and backward jets at the Tevatron

abstract:
  We analyse the azimuthal decorrelation of Mueller-Navelet dijets produced in
the collisions at Tevatron energies using a BFKL framework which incorporates
dominant subleading effects. We show that these effects significantly reduce
the decorrelation yet they are still insufficient to give satisfactory
description of experimental data. However a good description of the data is
obtained after incorporating within formalism the effective rapidity defined by
Del Duca and Schmidt.


title: Physics for the future colliders

abstract:
  Physics issues at the upcoming and planned colliders are discussed. We
critically review the the different arguments that suggest that New Physics is
bound to materialise at the TeV scale and why we should keep an open minded
approach. The complementarity of the LHC and a moderate energy e+ e- collider
is stressed together with the need for higher energy machines.


title:
Sudakov Resummation and Finite Order Expansions of Heavy Quark
  Hadroproduction Cross Sections

abstract:
  We resum Sudakov threshold enhancements in heavy quark hadroproduction for
single-heavy quark inclusive and pair-inclusive kinematics. We expand these
resummed results and derive analytical finite-order cross sections through
next-to-next-to-leading order. This involves the construction of
next-to-leading order matching conditions in color space. For the scale
dependent terms we derive exact results using renormalization group methods. We
study the effects of scale variations, scheme and kinematics choice on the
partonic and hadronic cross sections, and provide estimates for top and bottom
quark production cross sections.


title: The Standard Model on a D-brane

abstract:
  We present a consistent string theory model which reproduces the Standard
Model, consisting of a D3-brane at a simple orbifold singularity. We study some
simple features of the phenomenology of the model. We find that the scale of
stringy physics must be in the multi-TeV range. There are natural hierarchies
in the fermion spectrum and there are several possible experimental signatures
of the model.


title:
Electromagnetic Structure of the Nucleon in the Perturbative Chiral
  Quark Model

abstract:
  We apply the perturbative chiral quark model (PCQM) at one loop to analyse
the electromagnetic structure of nucleons. This model is based on an effective
Lagrangian, where baryons are described by relativistic valence quarks and a
perturbative cloud of Goldstone bosons. Including the electromagnetic
interaction we first develop the formalism up to one-loop in the Goldstone
boson fluctuation relying on renormalization by use of counterterms. Local
gauge invariance is satisfied both on the Lagrangian level and also for the
relevant baryon matrix elements in the Breit frame. We apply the formalism to
obtain analytical expressions for the nucleon charge and magnetic form factors,
which are expressed in terms of fundamental parameters of low-energy
pion-nucleon physics (weak pion decay constant, axial nucleon coupling, strong
pion-nucleon form factor) and of only one model parameter (radius of the
nucleonic three-quark core). A detailed numerical analysis for the nucleon
magnetic moments, charge and magnetic radii and also for the momentum
dependence of form factors is presented.


title: Nucleon Properties in the Perturbative Chiral Quark Model

abstract:
  We apply the perturbative chiral quark model (PCQM) to analyse low-energy
nucleon properties: electromagnetic form factors, meson-nucleon sigma-terms and
pion-nucleon scattering. Baryons are described as bound states of valence
quarks surrounded by a cloud of Goldstone bosons (pi, K, eta) as required by
chiral symmetry. The model is based on the following guide lines: chiral
symmetry constraints, fulfilment of low-energy theorems and proper treatment of
sea-quarks, that is meson cloud contributions. Analytic expressions for nucleon
observables are obtained in terms of fundamental parameters of low-energy
pion-nucleon physics (weak pion decay constant, axial nucleon coupling
constant, strong pion-nucleon form factor) and of only one model parameter
(radius of the nucleonic three-quark core). Our results are in good agreement
with experimental data and results of other theoretical approaches.


title:
Multiple-Scale Analysis and Renormalization of Quenched Second Order
  Phase Transitions

abstract:
  A quenched second order phase transition is modeled by an effective
$\Phi^4$-theory with a time-dependent Hamiltonian $\hat{H} (t)$, whose symmetry
is broken spontaneously in time. The quantum field evolves out of equilibrium
(nonequilibrium) during the phase transition as the density operator
significantly deviates from $\hat{\rho} (t) = e^{- \beta \hat{H} (t)}/Z_H$. The
recently developed Liouville-von Neumann (LvN) method provides various quantum
states for the phase transition in terms of a complex solution to the
mean-field equation, which is equivalent to the Gaussian effective potential in
the static case and to the time-dependent Hartree-Fock equation in the
nonequilibrium case. Using the multiple scale perturbation theory (MSPT) we
solve analytically the mean-field equation to the first order of coupling
constant and find the quantum states during the quenched second order phase
transition. We propose a renormalization scheme during the process of phase
transition to regularize the divergences, which originate from the mode
coupling between hard and hard modes or between the soft and hard modes. The
effect of mode coupling is discussed.


title: Hard exclusive meson production at next-to-leading order

abstract:
  We evaluate perturbative next-to-leading order corrections to the hard
exclusive leptoproduction of pi+ mesons on a transversely polarized proton
target. A model dependent study shows that these corrections can be large. We
analyze the scale dependence and explore the Brodsky-Lepage-Mackenzie scale
setting procedure. Although the predictions for the cross section suffer from
theoretical uncertainties, the transverse nucleon single spin asymmetry turns
out to be a rather stable observable since higher order effects approximately
cancel there.


title: Charmonium suppression in p-A collisions at RHIC

abstract:
  We discuss charmonium production in proton-nucleus collisions at RHIC
energies under the assumption of xF and x2 scaling. We find that all the
ambiguities due to energy loss are gone at this energy and therefore data will
reveal the scaling law, if any. These p-A data will also be crucial to
interpret nucleus-nucleus data with respect to a possible formation of a quark
gluon plasma because the extrapolations for charmonium production from the
present p-A data to RHIC energies, based on the two scaling laws, differ by a
factor of four.


title: Screened Potential of a Moving Meson In a Quark Gluon plasma

abstract:
  We consider the quark antiquark potential of a quarkonium moving with
velocity $v$ through a quark-gluon plasma at temperature T. An explicit,
configuration-space expression is found for the screened interaction between
the quarks constituting the meson. This potential is non-spherical, but axially
symmetric about the direction of $v$.