title:
Penetration of the Earth by ultrahigh energy neutrinos and the parton
  distributions inside the nucleon

abstract:
  In this talk we would like to present recent calculations of the cross
sections for the ultrahigh energy neutrinos interacting with nucleons. We
briefly present the framework of unifed BFKL/DGLAP equations which resums all
the leading log(1/x) effects as well as the subleading terms. The few free
parameters which specify the input parton distributions are determined by
fitting to HERA deep inelastic data. We then use these parton distributions to
calculate the cross section for the neutrino-nucleon interactions at very high
energies, up to 10^12 GeV.
  We do also investigate the attenuation of neutrinos when traversing through
the Earth. We use the transport equation which we solve for different fluxes of
high energy neutrinos (Active Galactic Nucleai, Gamma Ray Bursts, and top-down
models). We study the effects of the regeneration of the neutrino flux via
neutral current interaction.


title: BFKL and CCFM final states

abstract:
  I give a brief presentation of recent results on the equivalence of BFKL and
CCFM small-x final states, and discuss their implications for phenomenology.


title: On the Lifetime of the pi+pi- Atom

abstract:
  The pi+pi- atom decays -in the ground state - predominantly into two neutral
pions. We present a general expression for the corresponding decay width in the
framework of QCD (including photons). It contains all terms at leading and
next-to-leading order in isospin breaking. The result allows one to evaluate
the combination |a_0-a_2| of pi-pi S-wave scattering lengths from pi+pi-
lifetime measurements, like the one presently performed by the DIRAC experiment
at CERN.


title:
Higher twists and $\alpha_s(M_Z)$ extractions from the NNLO QCD analysis
  of the CCFR data for $xF_3$ structure function

abstract:
  A detailed next-to-next-to-leading order (NNLO) QCD analysis is performed for
the experimental data of the CCFR collaboration for the $xF_3$ structure
function. Theoretical ambiguities of the results of our NNLO fits are estimated
by application of the Pad\'e resummation technique and variation of the
factorization and renormalization scales. The NNLO and N$^3$LO $\alpha_s(Q^2)$
$\bar{MS}$-matching conditions are used. In the process of the fits we are
taking into account of twist-4 $1/Q^2$-terms. We found that the amplitude of
the $x$-shape of the twist-4 factor is decreasing in NLO and NNLO, though some
remaining twist-4 structure seems to retain in NNLO in the case when
statistical uncertainties are taken into account. The question of the stability
of these results to the application of the [0/2] Pad\'e resummation technique
is considered. Our NNLO results for $\alpha_s(M_Z)$ values, extracted from the
CCFR $xF_3$ data, are $\alpha_s(M_Z)=0.118 \pm 0.002 (stat) \pm 0.005 (syst)\pm
0.003 (theory)$ provided the twist-4 contributions are fixed through the
infrared renormalon model and $\alpha_s(M_Z)=0.121^{+0.007}_{0.010}(stat)\pm
0.005 (syst) \pm 0.003 (theory)$ provided the twist-4 terms are considered as
free parameters.


title: Direct collider signatures of large extra dimensions

abstract:
  The realization of low (TeV) scale strings usually requires the existence of
large (TeV) extra dimensions where gauge bosons live. The direct production of
Kaluza-Klein excitations of the photon and Z-boson at present and future
colliders is studied in this work. At the LEPII, NLC and Tevatron colliders,
these Kaluza-Klein modes lead to deviations from the standard model
cross-sections, which provide lower bounds on their mass. At the LHC the
corresponding resonances can be produced and decay on-shell, triggering a
characteristic pattern in the distribution of the dilepton invariant mass.


title:
QCD Factorization for $B\to\pi\pi$ Decays: Strong Phases and CP
  Violation in the Heavy Quark Limit

abstract:
  We show that, in the heavy quark limit, the hadronic matrix elements that
enter $B$ meson decays into two light mesons can be computed from first
principles, including `non-factorizable' strong interaction corrections, and
expressed in terms of form factors and meson light-cone distribution
amplitudes. The conventional factorization result follows in the limit when
both power corrections in $1/m_b$ and radiative corrections in $\alpha_s$ are
neglected. We compute the order-$\alpha_s$ corrections to the decays
$B_d\to\pi^+\pi^-$, $B_d\to\pi^0\pi^0$ and $B^+\to\pi^+\pi^0$ in the heavy
quark limit and briefly discuss the phenomenological implications for the
branching ratios, strong phases and CP violation.


title: Phenomenological Analysis of D Meson Lifetimes

abstract:
  The QCD-based operator-product-expansion technique is systematically applied
to the study of charmed meson lifetimes. We stress that it is crucial to take
into account the momentum of the spectator light quark of charmed mesons,
otherwise the destructive Pauli-interference effect in $D^+$ decays will lead
to a negative decay width for the $D^+$. We have applied the QCD sum rule
approach to estimate the hadronic matrix elements of color-singlet and
color-octet 4-quark operators relevant to nonleptonic inclusive $D$ decays. The
lifetime of $D_s^+$ is found to be longer than that of $D^0$ because the latter
receives a constructive $W$-exchange contribution, whereas the hadronic
annihilation and leptonic contributions to the former are compensated by the
Pauli interference. We obtain the lifetime ratio $\tau(D_s^+)/\tau(D^0)$
$\approx 1.08\pm 0.04$, which is larger than some earlier theoretical
estimates, but still smaller than the recent measurements by CLEO and E791.


title: Physics of the gauged four fermi model in $(1+1)$ dimensions

abstract:
  We analyze a two dimensional model of gauged fermions with quartic couplings
in the large-N limit. This combines the 't Hooft model and the Gross-Neveu
model where the coupling constants of both theories are arbitrary. Analytic
equations describing the meson states of the theory are derived and are solved
systematically using various methods. The physics of the model is investigated.


title:
Constraints on Parameters of the R_F Parity Model from Quark and
  Neutrino Mass Matrices

abstract:
  The forms of quark and lepton mass matrices are severely restricted in the
$R_F$ parity model. We determine the form of the quark mass matrix first and
derive the form of the neutrino mass matrix. For this to be consistent with the
present experiments, we conclude that the masses of the superpartners of the
right--handed down-type squarks and sneutrino vacuum expectation values
satisfy, ${m_{\tilde{d}_{Rj}}}\vmu \gtrsim 400 ~{\rm GeV}^2 $ or
${m_{\tilde{d}_{Rj}}}\vtau \gtrsim 400 ~{\rm GeV}^2 $. We also find that
without a sterile neutrino it is difficult to obtain a large mixing angle
solution of $\nu_\mu$ and $\nu_\tau$. With a sterile neutrino, we show a
possibility for a large mixing angle solution of $\nu_\mu$ with $\nu_{\rm
sterile}$.


title: Quark mass matrices and observable quantities

abstract:
  A nearly historical account of quark mass matrix models is given, and the
structure of quark mass matrices in the Standard Model is studied. For a
minimal parameter basis suggested earlier, where $M_u$ is diagonal and
$M_{d11}$, $M_{d13}$, $M_{d31}$ are zero, the dependence of mass matrices on
the CP violating phase $\delta$ of $V_{CKM}$ is reported: all parameters are
almost independent, except $M_{d22}$ and $M_{d23}$, and the equality
$|M_{d22}|=M_{d23}$ is obtained for a value of $\delta$ very close to the value
which is favoured by experiments. Moreover, on this basis, $M_{d12} \simeq
M_{d21}$ and $M_{d33} \simeq 2M_{d32}$. Some comments on mass matrices in
left-right symmetric models are added.


title: Nucleon Electric Dipole Moments from QCD Sum Rules

abstract:
  The electric dipole moments of nucleons (NEDM, d_N) are calculated using the
method of QCD sum rules. Our calculations are based on the parity and time
reversal violating parameter $\thetabar$ in QCD and establish a functional
dependence of the NEDM on $\thetabar$, without assuming a perturbative
expansion of this symmetry breaking parameter. The results obtained from the
QCD sum rules approach are shown to be consistent with the general symmetry
constraints on CP violations in QCD, including the necessity of: (1) finite
quark masses, (2) spontaneous chiral symmetry breaking, and (3) the U_A(1)
anomaly. Given the current experimental upper bound on the neutron electric
dipole moment (nEDM), d_n < 10^(-25) e-cm, we find | \thetabar | < 10^(-9).
This result is compatible with previous calculations of nEDM using different
techniques and excludes the possibility of solving the strong CP problem within
QCD via a dynamical suppression mechanism.


title:
Formation of color-singlet gluon-clusters and inelastic diffractive
  scattering

abstract:
  This is the extensive follow-up report of a recent Letter in which the
existence of self-organized criticality (SOC) in systems of interacting soft
gluons is proposed, and its consequences for inelastic diffractive scattering
processes are discussed. It is pointed out, that color-singlet gluon-clusters
can be formed in hadrons as a consequence of SOC in systems of interacting soft
gluons, and that the properties of such spatiotemporal complexities can be
probed experimentally by examing inelastic diffractive scattering. Theoretical
arguments and experimental evidences supporting the proposed picture are
presented --- together with the result of a systematic analysis of the existing
data for inelastic diffractive scattering processes performed at different
incident energies, and/or by using different beam-particles. It is shown in
particular that the size- and the lifetime-distributions of such gluon-clusters
can be directly extracted from the data, and the obtained results exhibit
universal power-law behaviors --- in accordance with the expected
SOC-fingerprints. As further consequences of SOC in systems of interacting soft
gluons, the $t$-dependence and the $(M_x^2/s)$-dependence of the double
differential cross-sections for inelastic diffractive scattering off
proton-target are discussed. Here $t$ stands for the four-momentum-transfer
squared, $M_x$ for the missing mass, and $\sqrt{s}$ for the total c.m.s.
energy. It is shown, that the space-time properties of the color-singlet
gluon-clusters due to SOC, discussed above, lead to simple analytical formulae
for $d^2\sigma/dt d(M_x^2/s)$ and for $d\sigma/dt$, and that the obtained
results are in good agreement with the existing data. Further experiments are
suggested.


title: Making glue in high energy nuclear collisions

abstract:
  We discuss a real time, non-perturbative computation of the transverse
dynamics of gluon fields at central rapidities in very high energy nuclear
collisions.


title: A 4-neutrino model with a Higgs triplet

abstract:
  We take as a starting point the Gelmini -- Roncadelli model enlarged by a
term with explicit lepton number violation in the Higgs potential and add a
neutrino singlet field coupled via a scalar doublet to the usual leptons. This
scenario allows us to take into account all three present indications in favour
of neutrino oscillations provided by the solar, atmospheric and LSND neutrino
oscillation experiments. Furthermore, it suggests a model which reproduces
naturally one of the two 4-neutrino mass spectra favoured by the data. In this
model the solar neutrino problem is solved by large mixing MSW \nu_e\to\nu_\tau
transitions and the atmospheric neutrino problem by transitions of \nu_\mu into
a sterile neutrino.


title:
Combined analysis of diffractive and inclusive structure functions in
  the semiclassical framework

abstract:
  Small-x DIS is described as the scattering of a partonic fluctuation of the
photon off a superposition of target color fields. Diffraction occurs if the
emerging partonic state is in a color singlet. Introducing a specific model for
the averaging over all relevant color field configurations, both diffractive
and inclusive parton distributions at some low scale Q_0^2 can be calculated. A
conventional DGLAP analysis results in a good description of diffractive and
inclusive structure functions at higher values of Q^2.


title: Generalized fluid dynamics and the boundary condition

abstract:
  We present the general formulation of the relativistic fluid dynamics with
vorticity (including relativistic superfluid) on a manifold with boundary.
Making use of the Hodge decomposition, we emphasize that the equations of
motion include a term due to non-trivial topology, while the pure vortex term
introduced by Carter and Langlois will be presented merely by a co-exact form.
We also consider a vortex sheet combined of individual vortices and discuss the
boundary problem.


title:
Analytical Result for Dimensionally Regularized Massless On-shell Double
  Box

abstract:
  The dimensionally regularized massless on-shell double box Feynman diagram
with powers of propagators equal to one is analytically evaluated for general
values of the Mandelstam variables s and t. An explicit result is expressed
either in terms of polylogarithms Li_a(-t/s), up to a=4, and generalized
polylogarithms S_{a,b}(-t/s), with a=1,2 and b=2, or in terms of these
functions depending on the inverse ratio, s/t.


title: The Infrared Behavior of Propagators in Landau Gauge QCD

abstract:
  A closed system of equations for the propagators of Landau gauge QCD is
obtained in a truncation scheme for their Dyson-Schwinger equations which
implements the Slavnov-Taylor identities for the 3-point vertex functions while
neglecting contributions from irreducible 4-point correlations. In the pure
gauge theory without quarks, non-perturbative solutions for the gluon and ghost
propagators are available in an approximation which allows for an analytic
discussion of their behavior in the infrared: The gluon propagator vanishes for
small spacelike momenta, whereas the ghost propagator is found to be infrared
enhanced. The running coupling of the non-perturbative subtraction scheme
approaches the finite value $\alpha_c \simeq 9.5$ at an infrared fixed point.
The gluon propagator entails a violation of positivity for transverse gluon
states implying their absence from a positive subspace expected for asymptotic
hadronic states and thus confinement. Both propagators, obtained for gluons and
ghosts in the present scheme, compare well with recent lattice calculations.
  In the quenched approximation, the quark propagator describes dynamical
chiral symmetry breaking well, although the corresponding interaction in the
gap equation for the quark self-energy is infrared suppressed. First results of
a simultaneous solution to the coupled system of gluons, ghosts {\sl and}
quarks indicate towards weak, and possibly negligible, vacuum polarisation
effects of dynamical quarks on the gluon and ghost correlations in the
infrared.


title: Symmetries of SU(2) Skyrmion in Hamiltonian and Lagrangian approaches

abstract:
  We apply the Batalin-Fradkin-Tyutin (BFT) method to the SU(2) Skyrmion to
study the full symmetry structure of the model at the first class Hamiltonian
level. On the other hand, we also analyze the symmetry structure of the action
having the WZ term, which corresponds to this Hamiltonian, in the framework of
the Lagrangian approach. Furthermore, following the BFV formalism we derive the
BRST invariant gauge fixed Lagrangian from the above extended action.


title:
The electroproduction of the $\Delta$(1232) in the chiral quark-soliton
  model

abstract:
  We calculate the ratios E2/M1 and C2/M1 for the electroproduction of the
$\Delta$(1232) in the region of photon virtuality $0<-q^2<1$ GeV$^2$. The
magnetic dipole amplitude M1 is also presented. The theory used is the chiral
quark-soliton model, which is based in the instanton vaccum of the QCD. The
calculations are performed in flavor SU(2) and SU(3) taking rotational
($1/N_c$) corrections into account. The results for the ratios agree
qualitatively with the available data, although the magnitude of both ratios
seems to underestimate the latest experimental results.


title: Flavor mixing and time of flight delay of supernova neutrinos

abstract:
  The neutrinos from galactic supernovae can be detected by the Sudbury
Neutrino Observatory and the Super-Kamiokande. The effect of neutrino mass can
show up in the observed neutrino signal by (i) delay in the time of flight and
(ii) distortion of the neutrino energy spectrum due to flavor mixing. We
discuss a combination of the two effects for both charged and neutral current
processes in the detectors for realistic three flavor scenarios and show that
neutrino flavor mixing can lead to non-trivial changes in the event rate as a
function of time.


title: The Pinch Technique Approach to the Physics of Unstable Particles

abstract:
  The consistent description of unstable particles within the framework of
perturbative gauge field theories necessitates the definition and resummation
of off-shell Green's functions, which must respect several crucial physical
requirements. We present the solution to this problem at one-loop, using the
pinch technique.


title:
Hadron Structure Functions in a Chiral Quark Model: Regularization,
  Scaling and Sum Rules

abstract:
  We provide a consistent regularization procedure for calculating hadron
structure functions in a chiral quark model. The structure functions are
extracted from the absorptive part of the forward Compton amplitude in the
Bjorken limit. Since this amplitude is obtained as a time-ordered correlation
function its regularization is consistently determined from the regularization
of the bosonized action. We find that the Pauli-Villars regularization scheme
is most suitable because it preserves both the anomaly structure of QCD and the
leading scaling behavior of hadron structure functions in the Bjorken limit. We
show that this procedure yields the correct pion structure function. In order
to render the sum rules of the regularized polarized nucleon structure
functions consistent with their corresponding axial charges we find it
mandatory to further specify the regularization procedure. This specification
goes beyond the double subtraction scheme commonly employed when studying
static hadron properties in this model. In particular the present approach
serves to determine the regularization prescription for structure functions
whose leading moments are not given by matrix elements of local operators. In
this regard we conclude somewhat surprisingly that in this model the Gottfried
sum rule does not undergo regularization.


title: The Higgs Boson: Shall We See It Soon Or Is It Still Far Away?

abstract:
  The status of the Higgs boson mass in the Standard Model and its
supersymmetric extensions is reviewed and the perspectives of Higgs searches
are discussed. The parameter space of the Minimal Supersymmetric Standard Model
(MSSM) is analysed with the emphasis on the lightest Higgs mass. The infrared
behaviour of renormalization group equations for the parameters of MSSM is
examined and infrared quasi-fixed points are used for the Higgs mass
predictions. They strongly suggest the Higgs mass to be lighter than 100 or 130
GeV for low and high $\tan\beta$ scenarios, respectively. Extended models,
however, allow one to increase these limits for low $\tan\beta$ up to 50%.


title: Radiative large-angle Bhabha scattering in collinear kinematics

abstract:
  The process of large-angle high energy electron-positron scattering with
emission of one hard photon almost collinear to one of the charged particles
momenta is considered. The differential cross section with radiative
corrections due to emission of virtual and soft real photons calculated to a
power accuracy is presented. Emission of two hard photons and total expressions
for radiative correction are given in leading logarithmical approximation. The
latter are illustrated by numeric estimates. A relation of the results with
structure function formalism is discussed.


title:
Off-diagonal quark distribution functions of the pion within an
  effective single instanton approximation

abstract:
  We develop a relativistic quark model for pion structure, which incorporates
the non-trivial structure of the vacuum of Quantum Chromodynamics as modelled
by instantons. Pions are boundstates of quarks and the strong quark-pion vertex
is determined from an instanton induced effective lagrangian. The interaction
of the constituents of the pion with the external electromagnetic field is
introduced in gauge invariant form. The parameters of the model, i.e.,
effective instanton radius and constituent quark masses, are obtained from the
vacuum expectation values of the lowest dimensional quark and gluon operators
and the low-energy observables of the pion. We apply the formalism to the
calculation of the pion form factor by means of the isovector nonforward parton
distributions and find agreement with the experimental data.


title: Ultra-High Energy Cosmic Rays and Stable H-dibaryon

abstract:
  It is shown that an instanton induced interaction between quarks produces a
very deeply bound H-dibaryon with mass below 2M_N, M_H=1718 MeV. Therefore the
H-dibaryon is predicted to be a stable particle. The reaction of
photodisintegration of H-dibaryon to $2\Lambda$ in during of its penetration
into cosmic microwave background will result in a new possible cut-off in the
cosmic-ray spectrum. This provides an explanation of ultra-high energy cosmic
ray events observed above the GZK cut-off as a result of the strong interaction
of high energy H-dibaryons from cosmic rays with nuclei in Earth's atmosphere.


title: Drell-Hearn-Gerasimov Sum Rule for the Nucleon in the Large-N_c Limit

abstract:
  We show that the Drell-Hearn-Gerasimov sum rule for the nucleon is entirely
saturated by the \Delta resonance in the limit of a large number of colors, N_c
\to \infty. Corrections are at relative order 1/N_c^2.


title: Impacts of the bounds on the Higgs mass and m_W on effective theories

abstract:
  We study the inter-relations that exist between the present experimental
bounds on the Higgs mass, as obtained from radiative corrections to $m_W$, and
the effective parameters, $\alpha_i$ and $\Lambda$. We find that the SM bounds
on $m_H$, arising from a precise determination of the $m_W$ mass, can be
substantially modified by the presence of dimension-6 operators which appear in
the linear realization of the effective Lagrangian approach. A Higgs mass as
heavy as 700 GeV can be allowed for scales of new physics of the order of 1
TeV.


title: Intrinsic transverse momentum and transverse spin asymmetries

abstract:
  We investigate leading twist transverse momentum dependent origins of
transverse spin asymmetries in hadron-hadron collisions. The chiral-odd T-odd
distribution function with intrinsic transverse momentum dependence, which
would signal an intrinsic handedness of quarks inside a hadron, could account
for single spin asymmetries and at the same time for the large cos(2 phi)
asymmetry in the unpolarized Drell-Yan cross section, which still lacks
understanding. We show explicitly how it would relate unpolarized and polarized
observables measurable with proton-proton collisions at RHIC. It would offer a
new possibility to access the transversity distribution function.


title:
Hard-thermal-loop Resummation of the Thermodynamics of a Hot Gluon
  Plasma

abstract:
  We calculate the thermodynamic functions of a hot gluon plasma to leading
order in hard-thermal-loop (HTL) perturbation theory. Effects associated with
screening, gluon quasiparticles, and Landau damping are resummed to all orders.
The ultraviolet divergences generated by the HTL propagator corrections can be
cancelled by a counterterm that depends on the thermal gluon mass parameter.
The HTL thermodynamic functions are compared to those from lattice gauge theory
calculations and from quasiparticle models. For reasonable values of the HTL
parameters, the deviations from lattice results for T > 2 T_c have the correct
sign and roughly the correct magnitude to be accounted for by next-to-leading
order corrections in HTL perturbation theory.


title:
Charmless Hardronic Decays $B_u \to V V $: Angular Distributions, Direct
  CP Violation and Determination of the Unitary Triangle

abstract:
  Two-body charmless nonleptonic decays of $B_u \to V V$ are studied within the
generalized factorization approach using a recent calculation of the effective
Wilson coefficients $c^{eff}_i$, which are not only renormalization-scale and
-scheme independent but also gauge invariant and infrared finite. After making
a universal ansatz for the nonfactorizable contributions, we parametrize these
effects in terms of $N_c^{eff}(LL)$ and $N_c^{eff}(LR)$, the effective numbers
of colors arising from $(V-A)(V-A)$ and $(V-A)(V+A)$ four-quark operators,
respectively. Three different schemes for these contributions are considered:
(i) the naive factorization, (ii) the large-N_c improved factorization, and
(iii) our preferred choice: $(N_c^{eff}(LL), N_c^{eff}(RR))=(2,5)$. We present
the full angular distribution of all charmless $B_u \to V V$ decays in both
transversity and helicity frames.Direct CP violation in these normalized
angular correlation coefficients is not negligible in $B^-_u \to K^{*-} \rho^0,
K^{*-} \omega$, and direct CP violation in the partial rate difference for
$B^-_u \to K^{*-} \omega, K^{*-} \rho$ and $\rho^- \omega$ can be as large as
45%, 25%, -10%, respectively. Due to the sizable QCD penguin contributions in
$\rho^- \omega$, the determination of the unitary triangle $\alpha$ via this
decay mode is more promising than via $\rho^- \rho^0$. It is also encouraging
to determine the unitary triangle $\gamma$ through $B^-_u \to K^{*-} \rho$
because of $N_c$-insensitivity and the not-so-small tree contribution. The
impacts of a negative $\rho$ on the branching ratios and CP violation are
studied. We also comment on the theoretical uncertainties and their possible
impacts.


title: Non-perturbative effects in the energy-energy correlation

abstract:
  The fully resummed next-to-leading-order perturbative calculation of the
energy-energy correlation in $e^+e^-$ annihilation is extended to include the
leading non-perturbative power-behaved contributions computed using the
``dispersive method'' applied earlier to event shape variables. The correlation
between a leading (anti)quark and a gluon produces a non-perturbative 1/Q
contribution, while non-perturbative effects in the quark-antiquark correlation
give rise to a smaller contribution $\ln Q^2/Q^2$. In the back-to-back region,
the power-suppressed contributions actually decrease much more slowly, as small
non-integer powers of 1/Q, as a result of the interplay with perturbative
effects. The hypothesis of a universal low-energy form for the strong coupling
relates the coefficients of these contributions to those measured for other
observables.


title: Neutrino mass induced radiatively by supersymmetric leptoquarks

abstract:
  We show how nonzero Majorana neutrino masses can be radiatively generated by
extending the MSSM with leptoquark chiral multiplets without violating
R-parity. It is found that, with these particles, the R-parity conservation
does not imply lepton number conservation. Neutrino masses generated at a
one-loop level are closely related to the down quark mass matrix. The ratio of
neutrino mass-squared splittings $\Delta m^2_{\nu_2-\nu_1}/\Delta
m^2_{\nu_3-\nu_2}$ obtained is naturally close to $\Delta m^2_{s-d}/\Delta
m^2_{b-s}\sim 10^{-3}$ which is in the right region required to explain both
the atmospheric neutrino data and the MSW solutions for the solar neutrino
data.


title: Radiation Zeros in W^+W^-\gamma Production at High-Energy Colliders

abstract:
  The vanishing of the cross section for particular points in phase space -
radiation zeros - is examined for the process $ q \bar q \to W^+W^- \gamma$ at
high energy. Unlike the process $q \bar q' \to W^\pm \gamma$, actual zeros only
occur in the soft-photon limit. However, for photon energies that are not too
large, the cross section does exhibit deep dips in regions of phase space
corresponding to the position of the actual zeros. We show that in these
regions the sensitivity to possible anomalous quartic couplings is very large.


title: On scale dependence of QCD string operators

abstract:
  We have obtained a general solution of evolution equations for QCD twist-2
string operators in form of expansion over complete set of orthogonal
eigenfunctions of evolution kernels in coordinate-space representation. In the
leading logarithmic approximation the eigenfunctions can be determined using
constraints imposed by conformal symmetry. Explicit formulae for the LO
scale-dependence of quark and gluon twist-2 string operators are given.


title: Skewed parton distributions for B->pi transitions

abstract:
  We investigate the b-u skewed parton distributions (SPDs) for B->pi
transitions and determine the contributions from several sources (overlaps of
soft light-cone wave functions, quark-antiquark annihilations and meson
resonances). The B->pi transition form factors, which are relevant in exclusive
semi-leptonic and non-leptonic B-decays, are obtained by integrating the b-u
SPDs over the momentum fraction x. A phenomenological determination of the
relevant parameters allows us to predict the form factors and to obtain the
branching ratios for semi-leptonic B->pi decays.


title:
On the extraction of non-perturbative effects in the fragmentation
  functions of heavy quarks in e+ e- annihilation

abstract:
  In this talk, we consider the computation of D and B fragmentation functions
in e+e- annihilation. We present an improved differential cross section that
merges together the O(alpha_s^2) fixed-order calculation and the
next-to-leading-logarithmic resummed one. We compare the results of fitting
present data using the next-to-leading-log cross section, the O(alpha_s^2)
fixed-order and the improved one.


title: The scalar meson puzzle beyond BCS

abstract:
  Les We present a new perspective on the scalar meson puzzle from spontaneous
breaking of chiral symmetry beyond BCS. We find that going beyond BCS does not
produce a systematic shift of the hadron spectrum. We also show that coupled
channels reduce the breaking of chiral symmetry, with the same Feynman diagrams
that appear in the coupling of a scalar meson to a pair of pseudoscalar mesons.
With a Lattice QCD inspired quark-quark interaction, we find that the
groundstate I=0, 3P0 quark antiquark meson is the f0(980) with a partial decay
width of 40MeV. We also find a 30% reduction of the chiral condensate due to
coupled channels.


title: SUSY QCD and Quintessence

abstract:
  Recent data point in the direction of a cosmological constant dominated
universe. We investigate the role of supersymmetric QCD with N_f < N_c as a
possible candidate for dynamical cosmological constant (``quintessence'').
  When N_f > 1, the multiscalar dynamics is fully taken into account, showing
that a certain degree of flavor symmetry in the initial conditions is necessary
in order to attain the required late-time ``tracking'' attractor behavior. A
possible solution to the problem of long-range interactions of gravitational
strength is proposed. Finally we show how, as a consequence of the interaction
with the Standard Model fields, the early cosmological evolution of the scalar
fields may be dramatically altered, and the approach to the tracking behavior
may become much more efficient.


title: Scalars from Top-condensation Models at Hadron Colliders

abstract:
  We study the production and decay of neutral scalars and pseudo-scalars at
hadron colliders, in theories where the top-quark mass is the result of a
$t\bar t$ condensate. We show that the dominant decay channel for masses below
the $t\bar t$ threshold is the flavor changing mode $tc$. This is a consequence
of the non-universal nature of the underlying interactions in all
top-condensation models and provides a model-independent signature of these
scenarios. We show that an upgraded Tevatron is sensitive to a sizeable region
of the interesting parameter space and that the LHC will highly constrain these
models through this flavor violating channel.


title:
Detailed Comparison of Next-to-Leading Order Predictions for Jet
  Photoproduction at HERA

abstract:
  The precision of new HERA data on jet photoproduction opens up the
possibility to discriminate between different models of the photon structure.
This requires equally precise theoretical predictions from perturbative QCD
calculations. In the past years, next-to-leading order calculations for the
photoproduction of jets at HERA have become available. Using the kinematic cuts
of recent ZEUS analyses, we compare the predictions of three calculations for
different dijet and three-jet distributions. We find that in general all three
calculations agree within the statistical accuracy of the Monte Carlo
integration yielding reliable theoretical predictions. In certain restricted
regions of phase space, the calculations differ by up to 5%.


title: Mirage gauge coupling unification

abstract:
  We use compact D=4, N=1, Type IIB orientifolds as a testing ground for recent
ideas about precocious gauge coupling unification and a low energy string
scale. We find that certain such orientifolds have the interesting property
that gauge couplings receive moduli-dependent corrections which mimic the
effect of field theoretical logarithmic running. The effective cut-off scale
for the logarithmic correction is not $M_{string}$ but rather
$M_X=\sqrt{\alpha}M_{Planck}M_c/M_{string}$, where $M_c$ is the
compactification scale. Thus there is just normal logarithmic running up to
$M_{string}$ and extra moduli dependent corrections which behave as if there
was further running to a higher virtual scale $M_X$. In this mechanism a
prominent role is played by anomalous U(1)'s with moduli dependent
Fayet-Iliopoulos terms. A vanishing FI-term fixes the modulus dependence of the
corrected gauge coupling. We discuss possible ways to implement this mechanism
in the context of a simple extension of the MSSM.


title: VMD, the WZW Lagrangian and ChPT: The Third Mixing Angle

abstract:
  We show that the Hidden Local Symmetry Model, supplemented with well-known
procedures for breaking flavor SU(3) and nonet symmetry, provides all the
information contained in the standard Chiral Perturbation Theory (ChPT)
Lagrangian ${\cal L}^{(0)}+{\cal L}^{(1)}$. This allows to rely on radiative
decays of light mesons ($VP\gamma$ and $P \gamma\gamma$) in order to extract
some numerical information of relevance to ChPT: a value for $\Lambda_1=0.20
\pm 0.04$, a quark mass ratio of $\simeq 21.2 \pm 2.4$, and a negligible
departure from the Gell-Mann--Okubo mass formula. The mixing angles are
$\theta_8=-20.40^\circ \pm 0.96^\circ$ and $\theta_0=-0.05^\circ \pm
0.99^\circ$. We also give the values of all decay constants. It is shown that
the common mixing pattern with one mixing angle $\theta_P$ is actually quite
appropriate and algebraically related to the $\eta/\eta'$ mixing pattern
presently preferred by the ChPT community. For instance the traditional
$\theta_P$ is functionally related to the ChPT $\theta_8$ and fulfills
$\theta_P \simeq \theta_8/2$. The vanishing of $\theta_0$, supported by all
data on radiative decays, gives a novel relation between mixing angles and the
violation of nonet symmetry in the pseudoscalar sector. Finally, it is shown
that the interplay of nonet symmetry breaking through U(3) $\ra$ SU(3)$\times$
U(1) satisfies all requirements of the physics of radiative decays without any
need for additional glueballs.


title: B -> X_u l nu decay distributions to order alpha_s

abstract:
  An analytic result for the O(alpha_s corrections to the triple differential B
-> X_u l nu decay rate is presented, to leading order in the heavy-quark
expansion. This is relevant for computing partially integrated decay
distributions with arbitrary cuts on kinematic variables. Several double and
single differential distributions are derived, most of which generalize known
results. In particular, an analytic result for the O(alpha_s) corrections to
the hadronic invariant mass spectrum is presented. The effects of Fermi motion,
which are important for the description of decay spectra close to infrared
sensitive regions, are included. The behaviour of perturbation theory in the
region of time-like momenta is also investigated


title:
Analysis on the diffractive production of W's and dijets at the DESY
  HERA and Fermilab Tevatron colliders

abstract:
  Hadronic processes in which hard diffractive production takes place have been
observed and analyzed in collider experiments for several years. The
experimental rates of diffractive W's and dijets measured at the Tevatron and
the cross sections of diffractively produced dijets recently obtained at the
HERA experiment are the object of this analysis. We use the Pomeron structure
function obtained from the HERA data by two different approaches to calculate
the rates and cross sections for these processes. The comparison of theoretical
predictions with the measured values reveals some discrepancies that make
evident conceptual difficulties with such approaches. A new version of the
Ingelman-Schlein model is proposed as an attempt to overcome such difficulties
and make theory and data compatible.


title:
Polarization effects on W boson pair productions with the extra neutral
  gauge boson at the e^+ e^- Linear Collider

abstract:
  We perform the comprehensive analysis of the polarization effects on the
e^+e^- -> W^+W^- process in the presence of the extra neutral gauge boson at
the LC energies. Consideration of the polarizations of the produced W bosons
and the beam polarizations provides substantial enhancements of the sensitivity
to the Z-Z' mixing angles in various models and the asymmetry variables also
give the strict constraints on the mixing angles. We find that the \chi-model
and the left-right model get the strict constraint from \sigma_{LL}^{unpol}
while the \psi-model and the \eta-model from the beam polarization asymmetry.


title:
Generating and Calculating One-loop Feynman Diagrams with FeynArts,
  FormCalc, and LoopTools

abstract:
  A set of programs is presented for automatically generating and calculating
Feynman diagrams. Diagrams are generated with FeynArts, then algebraically
simplified using a combination of Mathematica and FORM implemented in the
package FormCalc, and finally evaluated numerically using the LoopTools
package. FormCalc works either in dimensional regularization or in constrained
differential renormalization, the latter of which is equivalent at the one-loop
level to regularization by dimensional reduction. FormCalc combines the speed
of FORM with the powerful instruction set of Mathematica, and the latter
greatly eases further processing of the results (e.g. selecting or modifying
terms). The output is in a form well suited for numerical evaluation, which is
then straightforward using the implementations of the one-loop integrals in
LoopTools.


title: A Quark-Meson Model for Heavy Mesons: Semi-Leptonic Decays

abstract:
  I consider a model for heavy meson decays based on an effective quark-meson
Lagrangian. The model is constrained by the known symmetries of QCD in the m_Q
-> infinity limit for the heavy quarks, and chiral symmetry in the light quark
sector. Using a limited number of free parameters it is possible to compute
several phenomenological quantities, e.g. the leptonic B and B** decay
constants; the Isgur-Wise form factors: xi, tau(3/2), tau (1/2), describing the
semi-leptonic decays B -> D(*) l nu, B -> D** l nu; the form factors for heavy
to light decays B -> rho l nu, B -> a_1 l nu. I show that the semileptonic
heavy-to-light form factors calculated in the model fulfill the general
relations that hold in QCD in the large energy limit for the final hadron.


title: Is SAX J1808.4-3658 a Strange Star ?

abstract:
  One of the most important questions in the study of compact objects is the
nature of pulsars, including whether they are composed of $\beta$-stable
nuclear matter or strange quark matter. Observations of the newly discovered
millisecond X-ray pulsar \sax with the Rossi X-Ray Timing Explorer place firm
constraint on the radius of the compact star. Comparing the mass - radius
relation of \sax with the theoretical mass - radius relation for neutron stars
and for strange stars, we find that a strange star model is more consistent
with SAX J1808.4-3658, and suggest that it is a likely strange star candidate.


title: What comes beyond the standard model?

abstract:
  The Proceedings collects the results of ten days of discussions on the open
questions of the Standard electroweak model as well as the review of the
introductory talks, connected with the discussions.


title: Primordial Hypermagnetic Knots

abstract:
  Topologically non-trivial configurations of the hypermagnetic flux lines lead
to the formation of hypermagnetic knots (HK) whose decay might seed the Baryon
Asymmetry of the Universe (BAU).HK can be dynamically generated provided a
topologically trivial (i.e. stochastic) distribution of flux lines is already
present in the symmetric phase of the electroweak (EW) theory. In spite of the
mechanism generating the HK, their typical size must exceed the diffusivity
length scale. In the minimal standard model (MSM) (but not necessarily in its
supersymmetric extension) HK are washed out. A classical hypermagnetic
background in the symmetric phase of the EW theory can produce interesting
amounts of gravitational radiation.


title: Semileptonic B_c-meson decays in sum rules of QCD and NRQCD

abstract:
  The semileptonic B_c-meson decays into the heavy quarkonia J/\psi (\eta_c)
and a pair of leptons are investigated in the framework of three-point sum
rules of QCD and NRQCD. Calculations of analytical expressions for the spectral
densities of QCD and NRQCD correlators with account for the Coulomb-like
\alpha_s/v terms are presented. The generalized relations due to the spin
symmetry of NRQCD for the form factors of B_c\to J/\psi (\eta_c)l\nu_l
transitions with l denoting one of the leptons e, \mu or \tau, are derived at
the recoil momentum close to zero. This allows one to express all NRQCD form
factors through a single universal quantity, an analogue of Isgur-Wise function
at the maximal invariant mass of lepton pair. The gluon condensate corrections
to three-point functions are calculated both in full QCD in the Borel transform
scheme and in NRQCD in the moment scheme. This enlarges the parameteric
stability region of sum rule method, that makes the results of the approach to
be more reliable. Numerical estimates of widths for the transitions of B_c\to
J/\psi (\eta_c)l\nu_l are presented.


title:
Light-Cone Quark Model Analysis of Radially Excited Pseudoscalar and
  Vector Mesons

abstract:
  We present a relativistic constituent quark model to analyze the mass
spectrum and hadronic properties of radially excited u and d quark sector
mesons. Using a simple Gaussian function as a trial wave function for the
variational principle of a QCD motivated Hamiltonian, we obtain the mass
spectrum consistent with the experimental data. To do the same for several
observables such as decay constants and form factors, it seems necessary to
include both Dirac and Pauli form factors on the level of constituent quarks.
Taking into account the quark form factors, we thus present the generalized
formulas for the rho meson decay constant and form factors as well as the
$\pi\gamma$ transition form factor. We also predict several hadronic properties
for the radially excited states.


title:
pi0 pi0 Scattering Amplitudes in the pi- p Charge Exchange Process and
  pi0 pi0 Phase Shift Analysis

abstract:
  The amplitude analysis has been performed on the pi0 pi0 final state obtained
in the pi- p charge exchange process. The pi0 pi0 scattering amplitudes have
been obtained for the S and D waves by the Chew-Low extrapolation and the
partial wave analysis. Breit Wigner parameters have been obtained for f0(1370)
and f2(1270). I=0 S wave pi0 pi0 scattering phase shift has been obtained below
K Kbar threshold. They agree well with the pi+ pi- standard phase shift data
below 650GeV and deviate by about 10 degrees from the standard data above
650MeV. They show a different behavior from those of Cason and others. The pi0
pi0 phase shift data have been analyzed by the IA method. Resonance parameters
have been obtained to be m_sigma =588 pm 12MeV and Gamma_sigma =281 pm 25MeV
with r_c=2.76 pm 0.15GeV^-1. They are excellently in agreement with those
obtained in the reanlysis on the pi+ pi- phase shift data.


title:
Gauge Independence of Limiting Cases of One-Loop Electron Dispersion
  Relation in High-Temperature QED

abstract:
  Assuming high temperature and taking subleading temperature dependence into
account, gauge dependence of one-loop electron dispersion relation is
investigated in massless QED at zero chemical potential. The analysis is
carried out using a general linear covariant gauge. The equation governing the
gauge dependence of the dispersion relation is obtained and used to prove that
the dispersion relation is gauge independent in the limiting case of momenta
much larger than $eT$. It is also shown that the effective mass is not
influenced by the leading temperature dependence of the gauge dependent part of
the effective self-energy. As a result the effective mass, which is of order
$eT$, does not receive a correction of order $e^2T$ from one loop, independent
of the gauge parameter.


title:
Bs decays: CP asymmetries in left-right models with spontaneous CP
  violation

abstract:
  We present the contributions of new CP phases in CP asymmetries of two-body
neutral $B_s$ decays coming from a left--right model with spontaneous CP
violation. Large deviations from the Standard Model predictions can be
accommodated in a natural way by this type of models. The new physics effects
on the mixing, width difference and decays are analysed. In particular, we show
how the measurement of the angle $\gamma$ in electroweak penguin-dominated
processes can be largely affected.


title:
The effect of R parity violating couplings on e^-e^-->{\tilde e}_L
  {\tilde e}_R

abstract:
  In this work we study the effect of R parity breaking couplings on the
process e^-e^-->{\tilde e}_L{\tilde e}_R. We find that an e^-e^- linear
collider opearting at a center of mass energy of 500 Gev with a luminosity of
50 fb^{-1} will be able to probe the coupling
[\lambda_{211}+\lambda_{311}]^{1/2} down to .045 for a bino mass of 100 Gev and
selectron mass of 200 Gev. This would improve the current bound on it by a
factor of 3.5. More improved bounds can be obtained from precision measurement
of \sigma_{LR}-\sigma_{RR} which reduces the MSSM background.


title: Heavy Quark Production in Deep-Inelastic Scattering at HERA

abstract:
  We discuss two topics in the production of heavy quarks in deep-inelastic
scattering: the next-to-leading order Monte-Carlo HVQDIS and the
next-to-leading logarithmic resummation of soft gluon effects, including
estimates of next-to-next-to-leading order corrections therefrom.


title: Final-State Phases in Charmed Meson Two-Body Nonleptonic Decays

abstract:
  Observed decay rates indicate large phase differences among the amplitudes
for the charge states in $D \to \bar K \pi$ and $D \to \bar K^* \pi$ but
relatively real amplitudes in the charge states for $D \to \bar K \rho$. This
feature is traced using an SU(3) flavor analysis to a sign flip in the
contribution of one of the amplitudes contributing to the latter processes in
comparison with its contribution to the other two sets. This amplitude may be
regarded as an effect of rescattering and is found to be of magnitude
comparable to others contributing to charmed particle two-body nonleptonic
decays.


title:
Multiplicity Fluctuations in One- and Two-Dimensional Angular Intervals
  Compared with Analytic QCD Calculations

abstract:
  Multiplicity fluctuations in rings around the jet axis and in off-axis cones
have been measured by the DELPHI collaboration in $e^+e^-$ annihilations into
hadrons at LEP energies. The measurements are compared with analytical
perturbative QCD calculations for the corresponding multiparton system, using
the concept of Local Parton Hadron Duality. Some qualitative features are
confirmed by the data but substantial quantitative deviations are observed.


title:
Radial excitations of scalar and \eta, \eta' mesons in a chiral quark
  model

abstract:
  First radial excitations of the scalar meson nonet and pseudoscalar mesons
\eta, \eta' are described in a nonlocal chiral quark model of the
Nambu--Jona-Lasinio type with 't Hooft interaction. In this model simple form
factors are used, which allows us to describe first radial excitations of the
mesons and to conserve the gap equations describing spontaneous breaking of
chiral symmetry in the standard form. The external parameters of form factors
are fixed by masses of excited pseudoscalar mesons and the same form factors
are used for predicting the masses of excited scalar mesons. Strong decays of
excited scalar mesons and \eta, \eta' mesons are described in satisfactory
agreement with experiment.


title: Electroweak Symmetry Breaking and the Higgs Sector

abstract:
  These three lectures review the state of our understanding of electroweak
interactions and the search for the agent of electroweak symmetry breaking. The
themes of the lectures are (i) the electroweak theory and its experimental
status, (ii) the standard-model Higgs boson, and (iii) aspects of electroweak
theory beyond the standard SU(2)_L x U(1)_Y model.


title:
Critical Exponents of O(N) Scalar Model at Temperatures below the
  Critical Value using Auxiliary Mass Method

abstract:
  We investigate a phase transition of the O(N) invariant scalar model using
the auxiliary mass method. We determine the critical exponent $\beta$ by
calculating an effective potential below the critical temperature. This work
follows that of a previous paper.


title: Summary of the Experimental part of the XXXIVth Rencontre de Moriond

abstract:
  I summarise the experimental results presented during the hadronic session of
the XXXIVth Rencontre de Moriond.


title:
Deeply virtual electroproduction of photons and mesons on the nucleon :
  leading order amplitudes and power corrections

abstract:
  We estimate the leading order amplitudes for exclusive photon and meson
electroproduction reactions at large Q^2 in the valence region in terms of
skewed quark distributions. As experimental investigations can currently only
be envisaged at moderate values of Q^2, we estimate power corrections due to
the intrinsic transverse momentum of the partons in the meson wavefunction and
in the nucleon. To this aim the skewed parton distribution formalism is
generalized so as to include the parton intrinsic transverse momentum
dependence. Furthermore, for the meson electroproduction reactions, we
calculate the soft overlap type contributions and compare with the leading
order amplitudes. We give first estimates for these different power corrections
in kinematics which are relevant for experiments in the near future.


title: Local and global duality and the determination of \alpha(M_Z)

abstract:
  This talk presents work concepts and results for the determination of the
fine structure constant $\alpha$ at the $Z_0$ mass resonance. The problem
consisting of the break-down of global duality for singular integral weights is
circumvented by using a polynomial fit which mimics this weight function. This
method is conservative in the sense that it is mostly independent of special
assumptions. In this context the difference between local and global duality is
explained.


title: Anomalous Pseudoscalar-Photon Vertex In and Out of Equilibrium

abstract:
  The anomalous pseudoscalar-photon vertex is studied in real time in and out
of equilibrium in a constituent quark model. The goal is to understand the
in-medium modifications of this vertex, exploring the possibility of enhanced
isospin breaking by electromagnetic effects as well as the formation of neutral
pion condensates in a rapid chiral phase transition in peripheral,
ultrarelativistic heavy-ion collisions. In equilibrium the effective vertex is
afflicted by infrared and collinear singularities that require hard thermal
loop (HTL) and width corrections of the quark propagator. The resummed
effective equilibrium vertex vanishes near the chiral transition in the chiral
limit. In a strongly out of equilibrium chiral phase transition we find that
the chiral condensate drastically modifies the quark propagators and the
effective vertex. The ensuing dynamics for the neutral pion results in a
potential enhancement of isospin breaking and the formation of $\pi^0$
condensates. While the anomaly equation and the axial Ward identity are not
modified by the medium in or out of equilibrium, the effective real-time
pseudoscalar-photon vertex is sensitive to low energy physics.


title: An effective string theory of Abrikosov-Nielsen-Olesen vortices

abstract:
  We obtain an effective string theory of the Abrikosov-Nielsen-Olesen vortices
of the Abelian Higgs model. The theory has an anomaly free effective string
action which, when the extrinsic curvature is set equal to zero, yields the
Nambu-Goto action. This generalizes previous work in which a string
representation was obtained in the London limit, where the magnitude of the
Higgs field is fixed. Viewed as a model for long distance QCD, it provides a
concrete picture of the QCD string as a fluctuating Abrikosov-Nielsen-Olesen
vortex of a dual superconductor on the border between type I and type II.


title: Evolution and models for skewed parton distributions

abstract:
  We discuss the structure of the ``forward visible'' (FW) parts of double and
skewed distributions related to usual distributions through reduction
relations. We use factorized models for double distributions (DDs) f(x, alpha)
in which one factor coincides with the usual (forward) parton distribution and
another specifies the profile characterizing the spread of the longitudinal
momentum transfer. The model DDs are used to construct skewed parton
distributions (SPDs). For small skewedness, the FW parts of SPDs H(x, xi) can
be obtained by averaging forward parton densities f(x- xi alpha) with the
weight rho (alpha) coinciding with the profile function of the double
distribution f(x, alpha) at small x. We show that if the x^n moments f_n
(alpha) of DDs have the asymptotic (1-alpha^2)^{n+1} profile, then the
alpha-profile of f (x,alpha) for small x is completely determined by small-x
behavior of the usual parton distribution. We demonstrate that, for small xi,
the model with asymptotic profiles for f_n (alpha) is equivalent to that
proposed recently by Shuvaev et al., in which the Gegenbauer moments of SPDs do
not depend on xi. We perform a numerical investigation of the evolution
patterns of SPDs and gave interpretation of the results of these studies within
the formalism of double distributions.


title:
Prompt atmospheric neutrinos and muons: dependence on the gluon
  distribution function

abstract:
  We compute the next-to-leading order QCD predictions for the vertical flux of
atmospheric muons and neutrinos from decays of charmed particles, for different
PDF's (MRS-R1, MRS-R2, CTEQ-4M and MRST) and different extrapolations of these
at small partonic momentum fraction x. We find that the predicted fluxes vary
up to almost two orders of magnitude at the largest energies studied, depending
on the chosen extrapolation of the PDF's. We show that the spectral index of
the atmospheric leptonic fluxes depends linearly on the slope of the gluon
distribution function at very small x. This suggests the possibility of
obtaining some bounds on this slope in ``neutrino telescopes'', at values of x
not reachable at colliders, provided the spectral index of atmospheric leptonic
fluxes could be determined.


title: Conformal couplings and ``azimuthal matching'' of QCD Pomerons

abstract:
  Using the asymptotic conformal invariance of perturbative QCD we derive the
expression of the coupling of external states to all conformal spin-p
components of the forward elastic amplitude. Using the wave-function formalism
for structure functions at small x, we derive the perturbative coupling of the
virtual photon for p= 1, which is maximal for linear transverse polarization.
The non-perturbative coupling to the proton is discussed in terms of
``azimuthal matching'' between the proton color dipoles and the quark-
antiquark configurations of the photon. As an application, the recent
conjecture of a second QCD Pomeron related to the conformal spin-1 component is
shown to rely upon a strong azimuthal matching of the p= 1 component in gamma*
-proton scattering.


title: Recursion relations for two-loop self-energy diagrams on-shell

abstract:
  A set of recurrence relations for on-shell two-loop self-energy diagrams with
one mass is presented, which allows to reduce the diagrams with arbitrary
indices (powers of scalar propagators) to a set of the master integrals. The
SHELL2 package is used for the calculation of special types of diagrams. A
method of calculation of higher order \epsilon-expansion of master integrals is
demonstrated.


title: Low-energy neutrino-photon inelastic interactions

abstract:
  The computation of the polarized amplitudes and cross section of the
processes $\gamma\nu\to\gamma\gamma \nu$, $\gamma\gamma \to \gamma\nu\bar\nu$
and $\nu\bar\nu \to \gamma\gamma\gamma$ is described. We used an effective
lagrangian approach for energies below the threshold for $e^+e^-$ pair
production and the complete computation at higher energies for application in
supernova dynamics. Leading contributions of physics beyond the SM are also
commented.


title: Nearly degenerate neutrinos, Supersymmetry and radiative corrections

abstract:
  If neutrinos are to play a relevant cosmological role, they must be
essentially degenerate with a mass matrix of the bimaximal mixing type. We
study this scenario in the MSSM framework, finding that if neutrino masses are
produced by a see-saw mechanism, the radiative corrections give rise to mass
splittings and mixing angles that can accommodate the atmospheric and the
(large angle MSW) solar neutrino oscillations. This provides a natural origin
for the $\Delta m^2_{sol} << \Delta m^2_{atm}$ hierarchy. On the other hand,
the vacuum oscillation solution to the solar neutrino problem is always
excluded. We discuss also in the SUSY scenario other possible effects of
radiative corrections involving the new neutrino Yukawa couplings, including
implications for triviality limits on the Majorana mass, the infrared fixed
point value of the top Yukawa coupling, and gauge coupling and bottom-tau
unification.


title:
Large Possible retardation effects of quark confinement on the meson
  spectrum II

abstract:
  We present the results of a study of heavy-light-quark bound states in the
context of the reduced Bethe-Salpeter equation with relativistic vector and
scalar interactions. We find that satisfactory fits may also be obtained when
the retarded effect of the quark-antiquark interaction is concerned.


title: On Multiphoton Bremsstrahlung

abstract:
  Kinetic equations for the process of multiphoton bremsstrahlung of electron
in a matter have been used to derive the equations for the moments of
distributions of electrons over the number of emitted photons and over the
energy loss. The equations for the moments have been solved in continuous
slowing down approximation. It has been shown that the moments of multiphoton
distributions can be expressed in terms of the moments of macroscopic
differential cross section of the process. The results of analytical
calculations have been compared with the data of Monte Carlo simulation.


title: Instantons in the QCD Vacuum and in Deep Inelastic Scattering

abstract:
  We give a brief status report on our on-going investigation of the prospects
to discover QCD instantons in deep inelastic scattering (DIS) at HERA. A recent
high-quality lattice study of the topological structure of the QCD vacuum is
exploited to provide crucial support of our predictions for DIS, based on
instanton perturbation theory.


title:
Steps towards NNLO QCD calculations: collinear factorization at
  O(\alpha_S^2)

abstract:
  I consider the singular behaviour of tree-level QCD amplitudes when the
momenta of three partons become simultaneously parallel and I discuss the
universal factorization formula that controls the singularities of the
multiparton matrix elements in this collinear limit.


title: An update on vector boson pair production at hadron colliders

abstract:
  We present numerical results (including full one-loop QCD corrections) for
the processes p p-bar and pp -> W+ W-, W+/- Z/gamma* and Z/gamma* Z/gamma*
followed by the decay of the massive vector bosons into leptons. In addition to
their intrinsic importance as tests of the standard model, these processes are
also backgrounds to conjectured non-standard model processes. Because of the
small cross sections at the Tevatron, full experimental control of these
backgrounds will be hard to achieve. This accentuates the need for up-to-date
theoretical information. A comparison is made with earlier work and cross
section results are presented for p p-bar collisions at sqrt{s}=2 TeV and pp
collisions at sqrt{s}=14 TeV. Practical examples of the use of our calculations
are presented.


title:
Are there short distance non-perturbative contributions to the QCD
  static potential?

abstract:
  We find that perturbation theory fails to describe the short range static
potential as obtained from quenched lattice simulations, at least for source
separations r > 1/(6 GeV). The difference between the non-perturbatively
determined potential and perturbation theory at short distance is well
parameterised by a linear term with a slope of approximately 1.2 GeV^2 that is
significantly bigger than the string tension, sigma = 0.21 GeV^2


title:
Sterile Neutrinos in E_6 and a Natural Understanding of Vacuum
  Oscillation Solution to the Solar Neutrino Puzzle

abstract:
  If Nature has chosen the vacuum oscillation solution to the Solar neutrino
puzzle, a key theoretical challenge is to understand the extreme smallness of
the $\Delta m^2_{\nu_e-\nu_X}$ ($\sim 10^{-10} eV^2$) required for the purpose.
We find that in a class of models such as [SU(3)]^3 or its parent group E_6,
which contain one sterile neutrino, $\nu_{is}$ for each family, the $\Delta
m^2_{\nu_i-\nu_{is}}$ is proportional to the cube of the lepton Yukawa
coupling. Therefore fitting the atmospheric neutrino data then predicts the
$\nu_e-\nu_{es}$ mass difference square to be $\sim (\frac{m_e}{m_{\mu}})^3
\Delta m^2_{atmos}$, where the atmospheric neutrino data is assumed to be
solved via the $\nu_{\mu}-\nu_{\mu s}$ oscillation. This provides a natural
explanation of the vacuum oscillation solution to the solar neutrino problem.


title: Neutrinos and Muons from Atmospheric Charm

abstract:
  We evaluate the fluxes of neutrinos and muons from charmed particles produced
by cosmic ray interactions with air nuclei. Using next-to-leading order
perturbative QCD, we compare our results with calculations based on a PYTHIA
Monte Carlo evaluation of charm production. We investigate the sensitivity of
our results to the choice of parton distribution functions and the cosmic ray
spectrum. Perturbative QCD yields larger lepton fluxes than the PYTHIA
evaluation. The flux of muons from charm dominates the muon flux from pion and
kaon decays for energies above $\sim 10^5$ GeV.


title: Realistic Anomaly-mediated Supersymmetry Breaking

abstract:
  We consider supersymmetry breaking communicated entirely by the
superconformal anomaly in supergravity. This scenario is naturally realized if
supersymmetry is broken in a hidden sector whose couplings to the observable
sector are suppressed by more than powers of the Planck scale, as occurs if
supersymmetry is broken in a parallel universe living in extra dimensions. This
scenario is extremely predictive: soft supersymmetry breaking couplings are
completely determined by anomalous dimensions in the effective theory at the
weak scale. Gaugino and scalar masses are naturally of the same order, and
flavor-changing neutral currents are automatically suppressed. The most glaring
problem with this scenario is that slepton masses are negative in the minimal
supersymmetric standard model. We point out that this problem can be simply
solved by coupling extra Higgs doublets to the leptons. Lepton flavor-changing
neutral currents can be naturally avoided by approximate symmetries. We also
describe more speculative solutions involving compositeness near the weak
scale. We then turn to electroweak symmetry breaking. Adding an explicit \mu
term gives a value for B\mu that is too large by a factor of order 100. We
construct a realistic model in which the \mu term arises from the vacuum
expectation value of a singlet field, so all weak-scale masses are directly
related to m_{3/2}. We show that fully realistic electroweak symmetry breaking
can occur in this model with moderate fine-tuning.


title:
New Fits for the Non-Perturbative Parameters in the CSS Resummation
  Formalism

abstract:
  We update the non-perturbative function of the Collins-Soper- Sterman
resummation formalism in hadron collisions. Two functional forms in impact
parameter space are considered, one with a pure Gaussian form with two
parameters and the other with an additional linear term. The results for the
two parameter fit are found to be g1=0.24+0.08-0.07 GeV^2, g2=0.34+0.07-0.08
GeV^2. The results for the three parameter fit are g1=0.15+004-0.03 GeV^2,
g2=0.48+0.07-0.05 GeV^2, and g3=-0.58+0.26-0.20 GeV^-1. We discuss the
potential for the full Tevatron Run I Z boson data for further testing of the
universality of the non-perturbative function.


title:
Perturbative Effects in the Form Factor \gamma\gamma^*\to \pi and
  Extraction of the Pion Wave Function from CLEO Data

abstract:
  We study the pion form factor F^{\pi \gamma\gamma^*}(Q^2) in the light-cone
sum rule approach, accounting for radiative corrections and higher twist
effects.
  Comparing the results to the CLEO experimental data on F^{\pi
\gamma\gamma^*}(Q^2), we extract the the pion distribution amplitude of
twist-2. The deviation of the distribution amplitude from the asymptotic one is
small and is estimated to be a_2(\mu) = 0.12 \pm 0.03 at \mu=2.4 GeV, in the
model with one non-asymptotic term. The ansatz with two non-asymptotic terms
gives some region of a_2 and a_4, which is consistent with the asymptotic
distribution amplitude, but does not agree with some old models.


title: The annihilation decay B_c \to eta' l \nu

abstract:
  We first investigate the semileptonic annihilation decay B_c \to \eta' l\nu
in QCD. We find that the $\eta'$ momentum distribution is peaked within its
small recoil region due to the loop effects. The branching ratio is estimated
to be $ Br(B_c \to \eta' l\nu)=1.6\times 10^{-4}$ for $l=\mu,e$, which is
accessible at CERN LHC.


title: Interconnection Effects and W+W- Decays (a critical (p)(re)view)

abstract:
  Color reconnection and Bose-Einstein correlations not only can have an
influence on the measurement of the W-mass in the fully hadronic W+W- decay
channel at LEP2, but also can give essential information on the structure of
the QCD vacuum and the space-time development of a q_1\bar q_2 system. Recent
developments are critically analyzed, with particular emphasis on the models
used in this field. More sensitive variables are needed to distinguish between
color reconnection models, while more experimental knowledge has to be built
into the Bose-Einstein models and, above all, these two closely related
phenomena have to be treated in common. Both effects are determined by the
space-time overlap of the W+ and W- decay products. Vital experimental
information on the space-time development of the decay of the q_1\bar q_2
system is becoming available from the high-statistics data on hadronic Z decay
and models will have to be able to explain this evidence before being used to
predict interference effects in hadronic W+W- decay.


title:
Probing Large Extra Dimensions Using Top Production in Photon-Photon
  Collisions

abstract:
  Theories with large extra dimensions predict an infinite tower of
Kaluza-Klein states in the 1 TeV range, which can consequently have significant
implications for experimental observables. One such observable, which gets
affected by the exchange of spin-2 Kaluza-Klein particles, is the t t(bar)
production cross-section in photon-photon collisions at NLC energies. We study
this process and obtain bounds on the effective quantum gravity scale M_S
between 700 and 2400 GeV (depending on the centre-of-mass energy). We show that
the use of polarisation will further strengthen these bounds.


title: Study of leptoquark pair production at the LHC with the CMS detector

abstract:
  We study the discovery potential of the CMS detector for the scalar
leptoquark pair production at the LHC. Present and future exclusion limits are
considered. We find that the maximal leptoquark mass reach is about 1.47 TeV
for the branching ratio of Br(LQ_l -> l q)=100 %, while for Br(LQ_l -> l q)=50
% the upper limit is 1.2 TeV for an integrated luminosity of 100 fb-1. We
obtain comparable results for electron and muon-type leptoquarks. The pileup
effect at high luminosity is discussed.


title:
Constraining New Physics with the CDF Measurement of CP Violation in $B
  \to \psi K_S$

abstract:
  Recently, the CDF collaboration has reported a measurement of the CP
asymmetry in the $B\to\psi K_S$ decay: $a_{\psi K_S}=0.79^{+0.41}_{-0.44}$. We
analyze the constraints that follow from this measurement on the size and the
phase of contributions from new physics to $B-\barB$ mixing. Defining the
relative phase between the full $M_{12}$ amplitude and the Standard Model
contribution to be $2\theta_d$, we find a new bound: $\sin2\theta_d\gsim-0.6
(-0.87)$ at one sigma (95% CL). Further implications for the CP asymmetry in
semileptonic B decays are discussed.


title: Resonances in weak nonleptonic Omega^- decay

abstract:
  We examine the importance of J^P = 1/2^+, 1/2^- resonances for weak
nonleptonic Omega^- decays within the framework of chiral perturbation theory.
The spin-1/2 resonances are included into an effective theory and tree
contributions to the Omega^- decays are calculated. We find significant
contributions to the decay amplitudes and satisfactory agreement with
experiment. This confirms and extends previous results wherein such spin-1/2
resonances were included in nonleptonic and radiative-nonleptonic hyperon
decays.


title: Expected Muon Energy Spectra and Zenithal Distributions Deep Underwater

abstract:
  Energy spectra and zenith angle distributions of atmospheric muons are
calculated for the depths of operation of large underwater neutrino telescopes.
The estimation of the prompt muon contribution is performed with three
approaches to charm hadroproduction: recombination quark-parton model,
quark-gluon string model, and perturbative QCD based models. Calculations show
that the larger are zenith angles and water thickness above the detector, the
lower is the energy at which the prompt muon flux becomes equal to conventional
one (``crossing energy'') . For instance, for the depth of the Baikal Neutrino
Telescope and for zenith angle of 78 degrees the crossing energy is about 300
TeV, whereas it is only 8 TeV for the NESTOR depth. Nevertheless, the muon flux
of the crossing energy at NESTOR depth is in order of magnitude lower in
comparison with the Baikal depth.


title:
Constraints on spin observables in antiproton-proton to
  antiLambda-Lambda

abstract:
  It is recalled that spin-observables in the strangeness-exchange reaction
$\bar{p}{p} \to \bar{\Lambda}{\Lambda}$ are not independent but are related to
each other by simple algebraic relations. This provides constraints on the
existing data on polarization and spin-correlation coefficients, and also on
the forthcoming data obtained using a polarized proton target.


title: Formation of multiple winding topological defects in the early universe

abstract:
  The formation probability of multiple winding topological defects is
calculated by phase and flux distribution analysis based on the Kibble
mechanism. The core size of defects is taken into account so that when it is
much larger than the correlation length of the Higgs field, high winding
configuration can be realized. For example, if the self coupling constant of
the Higgs field is smaller than $4\times10^{-4}$, the topological inflation may
occur at the grand unification energy scale by the multiple winding string
produced during the GUT phase transition.


title: Leading nucleon and inelasticity in hadron-nucleus interactions

abstract:
  We present in this paper a calculation of the average proton-nucleus ine-
lasticity. Using an Iterative Leading Particle Model and the Glauber model, we
relate the leading particle distribution in nucleon-nucleus interactions with
the respective one in nucleon-proton collisions. To describe the leading
particle distribution in nucleon-proton collisions, we use the Regge-Mueller
formalism. To appear in Journal of Physics G.


title:
Measuring Gauge-Mediated SuperSymmetry Breaking Parameters at a 500 GeV
  e+e- Linear Collider

abstract:
  We consider the phenomenology of a class of gauge-mediated supersymmetry
(SUSY) breaking (GMSB) models at a e+e- Linear Collider (LC) with c.o.m. energy
up to 500 GeV. In particular, we refer to a high-luminosity (L ~ 3 x 10^34
cm^-2 s^-1) machine, and use detailed simulation tools for a proposed detector.
Among the GMSB-model building options, we define a simple framework and outline
its predictions at the LC, under the assumption that no SUSY signal is detected
at LEP or Tevatron. Our focus is on the case where a neutralino (N1) is the
next-to-lightest SUSY particle (NLSP), for which we determine the relevant
regions of the GMSB parameter space. Many observables are calculated and
discussed, including production cross sections, NLSP decay widths, branching
ratios and distributions, for dominant and rare channels. We sketch how to
extract the messenger and electroweak scale model parameters from a spectrum
measured via, e.g. threshold-scanning techniques. Several experimental methods
to measure the NLSP mass and lifetime are proposed and simulated in detail. We
show that these methods can cover most of the lifetime range allowed by
perturbativity requirements and suggested by cosmology in GMSB models. Also,
they are relevant for any general low-energy SUSY breaking scenario. Values of
c*tau_N1 as short as 10's of microns and as long as 10's of metres can be
measured with errors at the level of 10% or better after one year of LC running
with high luminosity. We discuss how to determine a narrow range (<~ 5%) for
the fundamental SUSY breaking scale sqrt(F), based on the measured m_N1,
c*tau_N1. Finally, we suggest how to optimise the LC detector performance for
this purpose.


title: Can One Measure the Weak Phase of a Penguin Diagram?

abstract:
  The b -> d penguin amplitude receives contributions from internal u, c and
t-quarks. We show that it is impossible to measure the weak phase of any of
these penguin contributions without theoretical input. However, it is possible
to obtain the weak phase if one makes a single assumption involving the
hadronic parameters. With such an assumption, one can test for the presence of
new physics in the b -> d flavour-changing neutral current by comparing the
weak phase of B_d^0-{\bar B}_d^0 mixing with that of the t-quark contribution
to the b -> d penguin.


title: A potential test of the CP properties and Majorana nature of neutrinos

abstract:
  The scattering of solar neutrinos on electrons may reveal their CP
properties, which are particularly sensitive to their Majorana nature. The
cross section is sensitive to the neutrino dipole moments through an
interference of electro-magnetic and weak amplitudes. We show how future solar
neutrino experiments with good angular resolution and low energy threshold,
such as Hellaz, can be sensitive to the resulting azimuthal asymmetries in
event number, and could therefore provide valuable information on the CP
properties and the nature of the neutrinos, provided the solar magnetic field
direction is fixed.


title: A remark on the muonium to antimuonium conversionin a 331 model

abstract:
  Here we analyze the relation between the search for muonium to antimuonium
conversion and the 331 model with doubly charged bileptons. We show that the
constraint on the mass of the vector bilepton obtained by experimental data can
be evaded even in the minimal version of the model since there are other
contributions to that conversion. We also discuss the condition for which the
experimental data constraint is valid.


title:
Flavor changing single top quark production channels at e^+e^- colliders
  in the effective Lagrangian description

abstract:
  We perform a global analysis of the sensitivity of LEP2 and e^+e^- colliders
with a c.m. energy in the range 500 - 2000 GeV to new flavor-changing single
top quark production in the effective Lagrangian approach. The processes
considered are sensitive to new flavor-changing effective vertices such as Ztc,
htc, four-Fermi tcee contact terms as well as a right-handed Wtb coupling. We
show that e^+ e^- colliders are most sensitive to the physics responsible for
the contact tcee vertices. For example, it is found that the recent data from
the 189 GeV LEP2 run can be used to rule out any new flavor physics that can
generate these four-Fermi operators up to energy scales of \Lambda > 0.7 - 1.4
TeV, depending on the type of the four-Fermi interaction. We also show that a
corresponding limit of \Lambda > 1.3 - 2.5 and \Lambda > 17 - 27 TeV can be
reached at the future 200 GeV LEP2 run and a 1000 GeV e^+e^- collider,
respectively. We note that these limits are much stronger than the typical
limits which can be placed on flavor diagonal four-Fermi couplings. Similar
results hold for \mu^+\mu^- colliders and for tu(bar) associated production.
Finally we briefly comment on the necessity of measuring all flavor-changing
effective vertices as they can be produced by different types of heavy physics.


title:
New Limits on the Couplings of Light Pseudoscalars from Equivalence
  Experiments

abstract:
  The exchange of light pseudoscalar quanta between fermions leads to
long-range spin-dependent forces in order g^2, where g is the
pseudoscalar-fermion coupling constant. We demonstrate that laboratory bounds
on the Yukawa couplings of pseudoscalars to nucleons can be significantly
improved using results from recent equivalence principle experiments, which are
sensitive to the spin-independent long-range forces that arise in order g^4
from two-pseudoscalar exchange.


title: High-Energy Hadron-Induced Dilepton Production from Nucleons and Nuclei

abstract:
  We review the production of high-mass lepton pairs in fixed-target
experiments, including both Drell-Yan (DY) and heavy quarkonium (J/Psi and
Upsilons) production.


title:
Generalized Sum Rules for Spin-Dependent Structure Functions of the
  Nucleon

abstract:
  The Drell-Hearn-Gerasimov and Bjorken sum rules are special examples of
dispersive sum rules for the spin-dependent structure function G_1(\nu, Q^2) at
Q^2=0 and \infty. We generalize these sum rules through studying the
virtual-photon Compton amplitudes S_1(\nu, Q^2) and S_2(\nu,Q^2). At small Q^2,
we calculate the Compton amplitudes at leading-order in chiral perturbation
theory; the resulting sum rules can be tested by data soon available from
Jefferson Lab. For Q^2>>\Lambda_{QCD}^2, the standard twist-expansion for the
Compton amplitudes leads to the well-known deep-inelastic sum rules. Although
the situation is still relatively unclear in a small intermediate-Q^2 window,
we argue that chiral perturbation theory and the twist-expansion alone already
provide strong constraints on the Q^2-evolution of the G_1(\nu,Q^2) sum rule
from Q^2=0 to Q^2=\infty.


title: Finite energy chiral sum rules in QCD

abstract:
  A set of well known chiral sum rules, expected to be valid in QCD, is
confronted with experimental data on the vector and axial-vector hadronic
spectral functions, obtained from tau-lepton decay by the ALEPH collaboration.
The Das-Mathur-Okubo sum rule, the first and second Weinberg sum rules, and the
electromagnetic pion mass difference sum rule are not well saturated by the
data. Instead, a modified set of sum rules having additional weight factors
that vanish at the end of the integration range on the real axis, is found to
be precociously saturated by the data to a remarkable extent.


title: NLL Corrections for B-Meson Radiative Exclusive Decays

abstract:
  We calculate the next-to-leading corrections to the branching ratio of
exclusive $B\to K^* \gamma$ decay. The renormalization scale dependence is
reduced compared to the leading logarithmic result but there remains a
dependence on a cutoff parameter of the hadronic model. The calculated
corrections increase the predicted branching ratio by about 10%, but it remains
in agreement with the experimental value.


title:
Precise measurement of Higgs decay rate into WW* at future e^+e^- Linear
  Colliders

abstract:
  Assuming a SM or MSSM scenario, one expects a light Higgs boson which could
be studied in great detail with a LC operating at \sqrt s>m_h+m_Z. In the TESLA
scenario, with 500 fb^-1 accumulated at \sqrt s = 350 GeV, about 10^5 hZ events
could be produced through the Higgstrahlung process. At a future LC with a \sim
1 cm beam-pipe radius and a thin Si detector there will be excellent separation
between the various flavours. With the high statistics available it will thus
become possible to measure the various branching ratios with a few % error.
Typically one expects 8 % precision on BR(h\to\bar cc), 6 % on BR(h\to gg) and
\sim 1 % on \sigma(hZ) x BR(h\to\bar bb) access to BR(h\to WW^*) and, as
explained in section 3, this measurement can give access to the Higgs total
decay width and therefore to all partial widths. In particular one can
precisely measure \Gamma(h\to\bar bb) and \Gamma(h\to\tau^+\tau^-) which have a
high sensitivity to MSSM effects\cite{gunion} and therefore allow an essential
test of the Higgs sector. If m_A < 1 TeV, it becomes possible to measure a
significant deviation and, within MSSM, to give an indirect estimate of m_A
thus extending the effective sensitivity above the discovery domain of LHC. In
the following section we describe a detailed analysis on the measurement of
BR(h\to WW^*).


title: Non-perturbative chiral corrections for lattice QCD

abstract:
  We explore the chiral aspects of extrapolation of observables calculated
within lattice QCD, using the nucleon magnetic moments as an example. Our
analysis shows that the biggest effects of chiral dynamics occur for quark
masses corresponding to a pion mass below 600 MeV. In this limited range chiral
perturbation theory is not rapidly convergent, but we can develop some
understanding of the behaviour through chiral quark models. This model
dependent analysis leads us to a simple Pad\'e approximant which builds in both
the limits $m_\pi \to 0$ and $m_\pi \to \infty$ correctly and permits a
consistent, model independent extrapolation to the physical pion mass which
should be extremely reliable.


title:
Probing the Nature of Compactification with Kaluza-Klein Excitations at
  the Large Hadron Collider

abstract:
  It is shown that the nature of compactification of extra dimensions in
theories of large radius compactification can be explored in several processes
at the Large Hadron Collider (LHC). Specifically it is shown that the
characteristics of the Kaluza-Klein (KK) excitations encode information on the
nature of compactification, i.e., on the number of compactified dimensions as
well as on the type of compactification, e.g., of the specific orbifold
compactification. The most dramatic signals arise from the interference pattern
involving the exchange of the Standard Model spin 1 bosons ($\gamma$ and Z) and
their Kaluza-Klein modes in the dilepton final state $pp\to l^+l^-X$. It is
shown that LHC with 100$fb^{-1}$ of luminosity can discover Kaluza-Klein modes
up to compactification scales of $\approx 6$ TeV as well as identify the nature
of compactification. Effects of the Kaluza-Klein excitations of the W boson and
of the gluon are also studied. Exhibition of these phenomena is given for the
case of one extra dimension and for the case of two extra dimensions with
$Z_2\times Z_2, Z_3$, and $Z_6$ orbifold compactifications.


title: Universal Seesaw Mass Matrix Model with an S_3 Symmetry

abstract:
  Stimulated by the phenomenological success of the universal seesaw mass
matrix model, where the mass terms for quarks and leptons f_i (i=1,2,3) and
hypothetical super-heavy fermions F_i are given by \bar{f}_L m_L F_R +\bar{F}_L
m_R f_R + \bar{F}_L M_F F_R + h.c. and the form of M_F is democratic on the
bases on which m_L and m_R are diagonal, the following model is discussed: The
mass terms M_F are invariant under the permutation symmetry S_3, and the mass
terms m_L and m_R are generated by breaking the S_3 symmetry spontaneously. The
model leads to an interesting relation for the charged lepton masses.


title: Deviations from the $1/r^2$ Newton law due to extra dimensions

abstract:
  We systematically examine corrections to the gravitational inverse square
law, which are due to compactified extra dimensions. We find the induced
Yukawa-type potentials for which we calculate the strength \alpha and range. In
general the range of the Yukawa correction is given by the wavelength of the
lightest Kaluza-Klein state and its strength, relative to the standard
gravitational potential, by the corresponding degeneracy. In particular, when n
extra dimensions are compactified on an n-torus, we find that the strength of
the potential is \alpha=2n, whereas the compactification on an n-sphere gives
\alpha= n+1. For Calabi-Yau compactifications the strength can be at most
\alpha=20.


title: Leading nucleon and the hadronic flux in the atmosphere

abstract:
  We present in this paper a calculation of the hadronic flux in the
atmosphere. Using an iterative leading particle model and the Glauber model, we
relate the moment of the leading particle distribution in nucleon-air
collisions with the respective one in nucleon-proton collisions. In this way,
we obtain a description of the nucleonic and hadronic fluxes in the atmosphere.
Contribution to the 26th International Cosmic Ray Conference, Salt Lake City -
Utah, August 1999 (HE 1.2.20).


title: Inelastic proton-air cross section in U.H.E

abstract:
  We calculate the inelastic proton-air cross section by means of the Glauber
model. As input, we use accelerator experimental data on the total
proton-proton cross section and compare with cosmic ray experimental data and
Monte Carlo simulations.
  Contribution to the 26th International Cosmic Ray Conference, Salt Lake City,
Utah. HE 1.3.13. August, 1999.


title: eta -> pi^+ pi^- pi^0 gamma in Chiral Perturbation Theory

abstract:
  We analyse the radiative decay $\eta \to \pi^+\pi^- \pi^0\gamma$ in the
low--energy expansion of the Standard Model. We employ the notion of
``generalized bremsstrahlung'' to take full advantage of the theoretical and
experimental information on the corresponding non-radiative $\eta \to 3 \pi$
decay. The direct emission amplitude of ${\cal O}(p^4)$ is due to one-loop
diagrams with intermediate pions (isospin violating) and kaons (isospin
conserving). The isospin conserving contributions to direct emission, including
vector meson exchange appearing at ${\cal O}(p^6)$, are suppressed.


title:
Mass bounds for Triplet Scalars of the Left-Right symmetric model and
  their future detection prospects

abstract:
  The standard formulation of the Left-Right symmetric model involves scalars
transforming as a triplet under SU(2)L. This multiplet contains particles which
are uncharged, singly-charged, and doubly-charged. We derive a bound on the
uncharged scalar mass of 55.4 GeV using results from LEP-II and find that a
range upto 110 GeV may be explored at the NLC at the 5sigma level. We also
discuss search strategies for the singly- and doubly-charged scalars at the
Tevatron and the LHC. Possible Standard Model backgrounds for the relevant
modes are estimated and compared with the signal. At the LHC, the prospects of
detecting the doubly-charged scalar are bright up to a mass of 850 GeV while
the 5sigma discovery limit of the singly-charged mode extends to 240 GeV for an
integrated luminosity of 100 inverse fb. At the Tevatron, with an integrated
luminosity of 25 inverse fb, the doubly-charged state can be detected if its
mass is less than 275 GeV while the reach for the singly charged scalar is 140
GeV.


title:
The Decay b -> s gamma, the Higgs Boson Mass, and Yukawa Unification
  without R-Parity

abstract:
  We review some properties of Bilinear R-Parity Violating models: simple
extensions of the Minimal Supersymmetric Standard Model motivated by
spontaneous breaking of R-Parity. We concentrate on the relaxation of the
bounds on the charged Higgs mass imposed by the measurement of B(b -> s gamma),
the effect on the mass of the lightest neutral Higgs boson, the radiative
breaking of the electroweak symmetry, the unification of bottom and tau Yukawa
couplings, and the relation of these phenomena to the radiatively generated
tau-neutrino mass.


title: Drell-Yan plus missing energy as a signal for extra dimensions

abstract:
  We explore the search sensitivity for signals of large extra dimensions at
hadron colliders via the Drell-Yan process pp -> l+ l- + E_T(miss) X (l = e,mu)
where the missing transverse energy is the result of escaping Kaluza-Klein
gravitons. We find that one is able to place exclusion limits on the gravity
scale up to 560 GeV at the Fermilab Tevatron, and to 4.0 (3.3) TeV at the CERN
LHC, for n = 3 (4) extra dimensions.


title: Corrections of Order \alpha_s^2 to the Forward-Backward Asymmetry

abstract:
  We calculate the second-order QCD corrections to the forward-backward
asymmetry in $e^+e^-$ annihilation. Using the quark axis definition, we do not
agree with either existing calculation, but the difference relative to one of
them is small and understood. In particular, we point out that the
forward-backward asymmetry of massive quarks is enhanced by logarithms of the
quark mass. This implies that the forward-backward asymmetry of massless quarks
is not computable in QCD perturbation theory and affected by
non-power-suppressed corrections coming from the non-perturbative fragmentation
functions. We also calculate the second-order corrections using the
experimentally-preferred thrust axis definition for the first time.


title: Measuring $\beta$ in $B \to D^{*+}D^{*-}K_s$ Decays

abstract:
  We consider the possibility of measuring both $\sin (2 \beta)$ and $\cos (2
\beta)$ in the KM unitarity triangle using the process $B^0 \to
D^{*+}D^{*-}K_s$. This decay mode has a higher branching fraction (O(1%)) than
the mode $B^0 \to D^{*+}D^{*-}$. We use the factorization assumption and heavy
hadron chiral perturbation theory to estimate the branching fraction and
polarization. The time dependent rate for $B^0(t) \to D^{*+} D^{*-} K_s$ can be
used to measure $\sin (2 \beta)$ and $\cos(2 \beta)$ . Furthermore, examination
of the $D^{*+} K_s$ mass spectrum may be the best way to experimentally find
the broad $1^+$ p-wave $D_s$ meson.


title: Exotic Explanations for Neutrino Anomalies

abstract:
  I review explanations for the three neutrino anomalies (solar, atmospheric
and LSND) which go beyond the ``conventional'' neutrino oscillations induced by
mass-mixing. Several of these require non-zero neutrino masses as well.


title:
Physical mechanisms generating spontaneous symmetry breaking and a
  hierarchy of scales

abstract:
  We discuss the phase transition in 3+1 dimensional lambda Phi^4 theory from a
very physical perspective. The particles of the symmetric phase (`phions')
interact via a hard-core repulsion and an induced, long-range -1/r^3
attraction. If the phion mass is sufficiently small, the lowest-energy state is
not the `empty' state with no phions, but is a state with a non-zero density of
phions Bose-Einstein condensed in the zero-momentum mode. The condensate
corresponds to the spontaneous-symmetry-breaking vacuum with <Phi> neq 0 and
its excitations ("phonons" in atomic-physics language) correspond to Higgs
particles. The phase transition happens when the phion's physical mass m is
still positive; it does not wait until m^2 passes through zero and becomes
negative. However, at and near the phase transition, m is much, much less than
the Higgs mass M_h. This interesting physics coexists with `triviality;' all
scattering amplitudes vanish in the continuum limit, but the vacuum condensate
becomes infinitely dense. The ratio m/M_h, which goes to zero in the continuum
limit, can be viewed as a measure of non-locality in the regularized theory. An
intricate hierarchy of length scales naturally arises. We speculate about the
possible implications of these ideas for gravity and inflation.


title: Theoretical Summary, Electroweak Physics

abstract:
  Aspects of theoretical electroweak physics are summarized, including the
status of electroweak radiative corrections, the hadronic contribution to the
running of alpha, global fits to precision data and their implication for
testing the standard model and constraining new physics, and electroweak
baryogenesis.


title:
Electric Dipole Moments and the Mass Scale of New T-Violating,
  P-Conserving Interactions

abstract:
  We consider the implications of experimental limits on the permanent electric
dipole moment (EDM) of the electron and neutron for possible new
parity-conserving (PC) time-reversal violating (TV) interactions. We show that
the constraints derived from one-loop contributions to the EDM exceed
previously reported two-loop limits by more than an order of magnitude and
imply a lower bound on the new TVPC mass scale $\lamtv$ of 100 TeV for new TVPC
strong interactions. These results imply a value of $10^{-15}$ or smaller for
the ratio of low-energy TVPC matrix elements to those of the residual strong
interaction.


title: Deformed Lorentz Symmetry and Ultra-High Energy Cosmic Rays

abstract:
  Lorentz symmetry violation (LSV) is often discussed using models of the
$TH\epsilon \mu $ type which involve, basically, energy independent parameters.
However, if LSV is generated at the Planck scale or at some other fundamental
length scale, it can naturally preserve Lorentz symmetry as a low-energy limit
(deformed Lorentz symmetry, DLS). Deformed relativistic kinematics (DRK) would
be consistent with special relativity in the limit $k$ (wave vector) $\to ~0$
and allow for a deformed version of general relativity and gravitation. We
present an updated discussion of the possible implications of this pattern for
cosmic-ray physics at very high energy. A $\approx ~10^{-6}$ LSV at Planck
scale, leading to a DLS pattern, would potentially be enough to produce very
important observable effects on the properties of cosmic rays at the $\approx
\~10^{20} eV$ scale (absence of GZK cutoff, stability of unstable particles,
lower interaction rates, kinematical failure of the parton model...). We
compare our approach with more recent similar claims made by S. Coleman and S.
Glashow from models of the $TH\epsilon \mu$ type.

categories: hep-ph astro-ph cond-mat hep-ex hep-th physics.hist-ph


title:
The lowest-order short-distance contribution to the
  $B_{s}\to\gamma\gamma$ decay

abstract:
  The complete calculation of the lowest order short-distance contributions to
the $B_{s}\to\gamma\gamma$ decay in the SM are presented. The amplitude and
branching ratio are calculated.


title: Relations among Elements of the Quark Mass Matrices

abstract:
  Current experimental data suggest some relations between the
Kobayashi-Maskawa Matrix and the quark mass ratios, namely $|V_{us}| \sim
\sqrt{m_d / m_s}$, $|V_{ub} / V_{cb}| \sim \sqrt{m_u / m_c}$ and $|V_{cb}| \sim
m_s / m_b$. We consider these relations seriously in this paper. As a result,
they offer us some attractive relations among the elements of the mass matrices
and bring us a problem. They might give us informations about the origin of
Yukawa couplings.


title: Factorization and Decay Constants $f_{D_s^*}$ and $f_{D_s}$

abstract:
  We calculate the decay constants of $D_s$ and $D_s^{*}$ with $\bar{B}^0 \ra
D^{+}\ell^{-}\nu$ and $\bar{B}^0 \ra D^{+}D_s^{-(*)}$ decays. In our analysis
we take the factorization method including non-factorizable term contributions
and used two different form factor behaviours (constant and monopole-type) for
$F_0(q^2)$. We also consider the QCD-penguin and Electroweak-penguin
contributions in hadronic decays within the NDR renormalization scheme at NLO
calculation. We estimate the decay constant of the $D_s$ meson to be $233\pm49$
${\rm MeV}$ for (pole/pole)-type form factor and $255\pm54$ ${\rm MeV}$ for
(pole/constant)-type form factor. For $D_s^{*}$ meson, we get $f_{D_s^{*}} =
346 \pm 82$ ${\rm MeV}$, and $f_{D_s^{*}}/f_{D_s} = 1.43 \pm 0.45$ for
(pole/constant)-type form factor.


title: Jet Production with Polarized Beams at Next-to-Leading Order

abstract:
  Jet production cross-sections in polarized proton-proton and electron-proton
collisions are studied to next-to-leading order accuracy. Phenomenological
results are presented for RHIC and HERA kinematics.


title: New Tests of Perturbative QCD Inspired by Hypothetical Tau Leptons

abstract:
  Inspired by the relation between the hadronic decay of the tau lepton and the
electron-positron annihilation into hadrons, we derive new tests of
perturbative QCD. We design a set of commensurate scale relations to test the
self-consistency of leading-twist QCD predictions for any observable which
defines an effective charge. This method provides renormalization scheme and
scale invariant probes of QCD which can be applied over wide data ranges.


title:
Implications of the precision data for very light Higgs boson scenario
  in 2HDM(II)

abstract:
  We present an up-to-date analysis of the constraints imposed bythe precision
data on the ($CP-$ conserving) Two-Higgs-Doublet Model of type II, with
emphasis on the possible existence of very light neutral (pseudo)scalar Higgs
boson with mass below 20--30 GeV. We show that even in the presence of such
light particles, the 2HDM(II) can describe the electroweak data with precision
comparable to that given by the SM. Particularly interesting lower limits on
the mass of the lighter neutral $CP-$even scalar $h^0$ are obtained in the
scenario with a light $CP-$odd Higgs boson $A^0$ and large $\tan\beta$.