title:
The matter effects to neutrino oscillations \nu_\mu \to \nu_e, \nu_\mu
  at very long baselines and the neutrino mixing angles \theta_13 and \theta_23

abstract:
  We study the matter effects to neutrino oscillations \nu_\mu \to \nu_e and
\nu_\mu \to \nu_\mu at very long baselines. It has been observed that, for a
very long baseline L~10000 km, the resonance peak for the \nu_\mu \to \nu_e
oscillation and the local minimum of the \nu_\mu survival probability occurs at
similar energies. With a good knowledge on the absolute value of \Delta
m_{31}^2, measurements of the above oscillation probabilities, P_{\mu e} and
P_{\mu\mu}, can be performed with the neutrino energy tuned to the resonance
peak of the \nu_\mu \to \nu_e oscillations. We show that the variations of CP
violating phase and the solar neutrino mixing parameters have negligible
effects on P_{\mu e} and P_{\mu\mu} for such a long baseline. Hence P_{\mu e}
and P_{\mu\mu} together determine the mixing angles \theta_{13} and
\theta_{23}. Around the resonance peak for \nu_\mu \to \nu_e oscillations, the
dependencies of P_{\mu e} and P_{\mu\mu} on the above mixing angles are worked
out in detail, and the implications of such dependencies are discussed.


title:
Stability of Proton and Maximally Symmetric Minimal Unification Model
  for Basic Forces and Building Blocks of Matter

abstract:
  With the hypothesis that all independent degrees of freedom of basic building
blocks should be treated equally on the same footing and correlated by a
possible maximal symmetry, we arrive at an 4-dimensional space-time unification
model. In this model the basic building blocks are Majorana fermions in the
spinor representation of 14-dimensional quantum space-time with a gauge
symmetry $G = SO(1,3)\times SU(32)\times U(1)_A \times SU(3)_F$. The model
leads to new physics including mirror particles of the standard model. It
enables us to issue some fundamental questions that include: why our living
space-time is 4-dimensional, why parity is not conserved in our world, how is
the stability of proton, what is the origin of CP violation and what can be the
dark matter.


title:
Toward dynamical understanding of the diquarks, pentaquarks and
  dibaryons

abstract:
  QCD instantons are known to produce deeply bound diquarks. We study whether
it may be used as building blocks in the formation of multiquark states, in
particular pentaquarks and dibaryons.
  A simple model is presented in which the lowest scalar diquark (and possibly
the tensor one) can be treated as an independent ``body'', with the same color
and (approximately) the same mass as a constituent (anti)quark. In it a new
symmetry exists between states with the same number of ``bodies'' but different
number of quarks appear, in particular the 3-``body'' pentaquarks can be
naturally related to some excited baryons. The limitations of this model are
seen from the fact that it leads to light dibaryon $H$. Another reported work
is based on a calculation of a large set of correlation functions for nonlocal
operators with 4 to 6 light quarks in the Random Instanton Liquid Model (RILM).
  The effective interaction between diquarks is studied and found to posses a
strongly {\em repulsive core}, due to the Pauli principle for quark zero modes.


title:
An approach to NLO QCD analysis of the semi-inclusive DIS data with
  modified Jacobi polynomial expansion method

abstract:
  It is proposed the modification of the Jacobi polynomial expansion method
(MJEM) which is based on the application of the truncated moments instead of
the full ones. This allows to reconstruct with a high precision the local quark
helicity distributions even for the narrow accessible for measurement Bjorken
$x$ region using as an input only four first moments extracted from the data in
NLO QCD. It is also proposed the variational (extrapolation) procedure allowing
to reconstruct the distributions outside the accessible Bjorken $x$ region
using the distributions obtained with MJEM in the accessible region. The
numerical calculations encourage one that the proposed variational
(extrapolation) procedure could be applied to estimate the full first
(especially important) quark moments.


title: The $\nu$MSM, Dark Matter and Baryon Asymmetry of the Universe

abstract:
  We show that the extension of the standard model by three right-handed
neutrinos with masses smaller than the electroweak scale (the $\nu$MSM) can
explain simultaneously dark matter and baryon asymmetry of the universe and be
consistent with the experiments on neutrino oscillations. Several constraints
on the parameters of the $\nu$MSM are derived.


title:
Inclusive production of a Higgs or Z boson in association with heavy
  quarks

abstract:
  We calculate the cross section for the production of a Z boson in association
with heavy quarks. We suggest that this cross section can be measured using an
inclusive heavy-quark tagging technique. This could be used as a feasibility
study for the search for a Higgs boson produced in association with bottom
quarks. We argue that the best formalism for calculating that cross section is
based on the leading-order process b b -> h, and that it is valid for all Higgs
masses of interest at both the Fermilab Tevatron and the CERN Large Hadron
Collider.


title:
Exploration prospects of a long baseline Beta Beam neutrino experiment
  with an iron calorimeter detector

abstract:
  A high intensity source of a single neutrino flavour with known spectrum is
most desirable for precision measurements, the consensus direction for the
future. The beta beam is an especially suitable option for this. We discuss the
prospects of a very long baseline beta beam experiment with a magnetized iron
calorimeter detector. In particular, with the source at CERN and the detector
at the proposed India-based Neutrino Observatory (INO) the baseline is near the
`magic' value where the effect of the CP phase is small. We observe that this
experiment will be well suited to determine the sign of $m_3^2 - m_2^2$ and
will be capable of probing $\theta_{13}$ down to about 1$^\circ$.


title: On the infrared freezing of perturbative QCD in the Minkowskian region

abstract:
  The infrared freezing of observables is known to hold at fixed orders of
perturbative QCD if the Minkowskian quantities are defined through the analytic
continuation from the Euclidean region. In a recent paper [1] it is claimed
that infrared freezing can be proved also for Borel resummed all-orders
quantities in perturbative QCD. In the present paper we obtain the Minkowskian
quantities by the analytic continuation of the all-orders Euclidean amplitudes
expressed in terms of the inverse Mellin transform of the corresponding Borel
functions [2]. Our result shows that if the principle of analytic continuation
is preserved in Borel-type resummations, the Minkowskian quantities exhibit a
divergent increase in the infrared regime, which contradicts the claim made in
[1]. We discuss the arguments given in [1] and show that the special
redefinition of Borel summation at low energies adopted there does not
reproduce the lowest order result obtained by analytic continuation.


title: The intrinsic and oscillated astrophysical neutrino flavor ratios

abstract:
  The pp interactions taking place in the cosmos around us are a source of the
astrophysical neutrinos of all the three flavors. In these interactions, the
electron and the muon neutrinos mainly come from the production and the decay
of the \pi^{\pm} mesons, whereas the tau neutrinos mainly come from the
production and the decay of the D^{\pm}_{S} mesons. We estimate the three
intrinsic neutrino flavor ratios for 1 GeV < E < 10^{12} GeV in the pp
interactions and found them to be 1 : 2 : 3\times 10^{-5}. We study the effects
of neutrino oscillations on these intrinsic ratios. We point out that the three
ratios become 1 : 1 : 1 if L(pc)/E(GeV)> 10^{-10} in the presence of neutrino
oscillations, where L is the distance to the astrophysical neutrino source in
units of parsecs.


title: New Physics in B and K Decays

abstract:
  Flavour physics offers interesting probes for the exploration of the Standard
Model and the search for new physics. In these lectures, we focus on B- and
K-meson decays, introduce the concept of low-energy effective Hamiltonians to
describe them theoretically, and discuss how physics beyond the Standard Model
may generically affect the roadmap of quark-flavour physics. We address then
both the implications of the B-factory data for the B_d -> J/psi K_S channel
and the prospects of B_s -> J/psi phi modes for hadron colliders, and discuss
how the Standard Model may be challenged through B_d -> phi K_S. Finally, as an
example of a systematic flavour strategy to search for new physics, we analyze
puzzling patterns in the B -> pi pi, pi K data and study their interplay with
rare K and B decays.


title: Direct detection of neutralino dark matter in supergravity

abstract:
  The direct detection of neutralino dark matter is analysed in general
supergravity scenarios, where non-universal soft scalar and gaugino masses can
be present. In particular, the theoretical predictions for the
neutralino-nucleon cross section are studied and compared with the sensitivity
of dark matter detectors. We take into account the most recent astrophysical
and experimental constraints on the parameter space, including the current
limit on B(Bs-> mu+ mu-). The latter puts severe limitations on the dark matter
scattering cross section, ruling out most of the regions that would be within
the reach of present experiments. We show how this constraint can be softened
with the help of appropriate choices of non-universal parameters which increase
the Higgsino composition of the lightest neutralino and minimise the chargino
contribution to the b->s transition.


title: Direct CP Violation in Hadronic B Decays

abstract:
  There are different approaches for the hadronic B decay calculations,
recently. In this paper, we upgrade three of them, namely factorization, QCD
factorization and the perturbative QCD approach based on $k_T$ factorization,
by using new parameters and full wave functions.
  Although they get similar results for many of the branching ratios, the
direct CP asymmetries predicted by them are different, which can be tested by
recent experimental measurements of B factories.


title: Seesaw Right Handed Neutrino as the Sterile Neutrino for LSND

abstract:
  We show that a double seesaw framework for neutrino masses with $\mu-\tau$
exchange symmetry can lead to one of the righthanded seesaw partners of the
light neutrinos being massless. This can play the role of a light sterile
neutrino, giving a $3+1$ model that explains the LSND results. We get a very
economical scheme, which makes it possible to predict the full $4\times 4$
neutrino mass matrix if CP is conserved. Once CP violation is included, effect
of the LSND mass range sterile neutrino is to eliminate the lower bound on
neutrinoless double beta decay rate which exists for the three neutrino case
with inverted mass hierarchy. The same strategy can also be used to generate a
natural $3+2$ model for LSND, which is also equally predictive for the CP
conserving case in the limit of exact $\mu-\tau$ symmetry.


title: Beam normal spin asymmetry in the equivalent photon approximation

abstract:
  The two-photon exchange contribution to the single spin asymmetries with the
spin orientation normal to the reaction plane is discussed for elastic
electron-proton scattering in Regge regime. For this, the equivalent photon
approximation is adopted. In this case, hadronic part of the two-photon
exchange amplitude describes real Compton scattering (RCS). The imaginary part
of helicity conserving RCS amplitudes are related to total photoabsorption
cross section. The contribution of the photon helicity flipping amplitudes is
estimated by the two pion exchange in the $t$-channel. We observe the double
logarithmic enhancement in the electron mass but find it's contribution to the
asymmetry negligibly small in the forward kinematics. These results are in
strong disagreement with the existing calculation.


title:
Neutron tagging of quasielastic J/psi photoproduction off nucleus in
  ultraperipheral heavy ion collisions at RHIC energies

abstract:
  We compare the coherent and quasielastic J/psi photoproduction in the
peripheral heavy ion collisions in kinematics of RHIC. Our improved estimate of
the total coherent cross section is a factor of two smaller than the earlier
ones. We find that the counting rate of quasielastic J/psi photoproduction
tagged by neutrons emitted due to cascading of the recoiled nucleon within the
residual nucleus exceeds the rate of the coherent events. We argue that
measurements of this process can be used to learn about the dynamics of color
dipole-nucleon interactions in nuclei in the wide effective range of energies
of gamma A interactions.


title: How to Detect Big Bang Relic Neutrinos?

abstract:
  The existence of big bang relic neutrinos - exact analogues of the big bang
relic photons comprising the cosmic microwave background radiation - is a basic
prediction of standard cosmology. At present, the observational evidence for
their existence rests entirely on cosmological measurements, such as the light
elemental abundances, anisotropies in the cosmic microwave background, and the
large-scale matter power spectrum. In this review, we concentrate on the
prospects of more direct, weak interaction based relic neutrino detection
techniques which are sensitive to the cosmic neutrino background near the
present epoch and in our local neighborhood in the universe. In this
connection, we emphasize the necessity to take into account the gravitational
clustering of the relic neutrinos in the cold dark matter halos of our Milky
Way and nearby galaxy clusters.


title: Dynamic canonical suppression of strangeness in transport models

abstract:
  It is investigated whether canonical suppression associated with the exact
conservation of an U(1)-charge can be reproduced correctly by current transport
models. Therefore a pion-gas having a volume-limited cross section for kaon
production and annihilation is simulated within two different transport
prescriptions for realizing the inelastic collisions. It is found that both
models can indeed dynamically account for the canonical suppression in the
yields of rare strange particles.


title:
Holes in the walls: primordial black holes as a solution to the
  cosmological domain wall problem

abstract:
  We propose a scenario in which the cosmological domain wall and monopole
problems are solved without any fine tuning of the initial conditions or
parameters in the Lagrangian of an underlying filed theory. In this scenario
domain walls sweep out (unwind) the monopoles from the early universe, then the
fast primordial black holes perforate the domain walls, change their topology
and destroy them. We find further that the (old vacuum) energy density released
from the domain walls could alleviate but not solve the cosmological flatness
problem.


title: Family Dependence in SU(3)_C X SU(3)_L X U(1)_X models

abstract:
  Using experimental results at the Z-pole and atomic parity violation, we
perform a chi-squared fit at 95% CL to obtain family-dependent bounds to Z_2
mass and Z-Z' mixing angle in the framework of SU(3)_C X SU(3)_L X U(1)_X
models. The allowed regions depend on the assignment of the quark families in
mass eigenstates into the three different families in weak eigenstates that
cancel anomalies


title: Estimate of neutrino masses from Koide's relation

abstract:
  We apply Koide's mass relation of charged leptons to neutrinos and quarks,
with both the normal and inverted mass schemes of neutrinos discussed. We
introduce the parameters $k_{\nu}$, $k_u$ and $k_d$ to describe the deviations
of neutrinos and quarks from Koide's relation, and suggest a quark-lepton
complementarity of masses such as $ k_{l}+k_{d} \approx k_{\nu}+k_{u} \approx
2$. The masses of neutrinos are determined from the improved relation, and they
are strongly hierarchical (with the different orders of magnitude of $10^{-5}
eV$, $10^{-3} eV$, and $10^{-2} eV$).

categories: hep-ph astro-ph hep-ex math-ph math.MP nucl-ex nucl-th


title: Lorentz Violating Supersymmetric Quantum Electrodynamics

abstract:
  Theory of Supersymmetric Quantum Electrodynamics is extended by interactions
with external vector and tensor backgrounds, that are assumed to be generated
by some Lorentz-violating (LV) dynamics at an ultraviolet scale perhaps related
to the Planck scale. Exact supersymmetry requires that such interactions
correspond to LV operators of dimension five or higher, providing a solution to
the naturalness problem in the LV sector. We classify all dimension five and
six LV operators, analyze their properties at the quantum level and describe
observational consequences of LV in this theory. We show that LV operators do
not induce destabilizing D-terms, gauge anomaly and the Chern-Simons term for
photons. We calculate the renormalization group evolution of dimension five LV
operators and their mixing with dimension three LV operators, controlled by the
scale of the soft-breaking masses. Dimension five LV operators are constrained
by the low-energy precision measurements at 10^{-10}-10^{-5} level in units of
the inverse Planck scale, while the Planck-scale suppressed dimension six LV
operators are allowed by observational data.


title:
Quark mass effects in the soft-collinear effective theory and B -> X_s +
  photon in the endpoint region

abstract:
  We consider the effects of a light quark mass in the soft-collinear effective
theory (SCET) and we apply them to B -> X_s gamma in the endpoint region. We
find that the reparameterization invariance can be extended by including the
collinear quark mass in the SCET Lagrangian. This symmetry constrains the
theory with the quark mass terms, and we present explicit results at one loop.
It also relates the Wilson coefficients of some mass operators to those of the
leading operators, which are useful in organizing the subleading effects due to
the quark mass in B -> X_s gamma. We present strange quark mass corrections to
B -> X_s gamma in the endpoint region as an application. The forward scattering
amplitude from the mass corrections is factorized, and it can be expressed as a
convolution of the m_s^2/p_X^2-suppressed jet function and the leading-order
shape function of the B meson. This contribution should be added to the
existing subleading contributions from the B meson shape functions to obtain
complete subleading corrections.


title: Prediction of Ue3 and \cos 2\theta_23 from discrete symmetry

abstract:
  We discuss the question why the mixing $U_{e3}$ is small. The natural answer
is $U_{e3}=0$ in some symmetric limit, in which two large mixings are realized.
It is possible to force $U_{e3}$ and $\cos{2 \theta_{23}}$ to be zero by
imposing a discrete symmetry. We investigate a special class of symmetries
$Z_2$ and of the consequences of their perturbative violation.


title:
J/$\psi$ suppression at $\sqrt{{\bf s}} =$ 200 GeV in the comovers
  interaction model

abstract:
  The yield of $J/\psi$ per binary nucleon-nucleon collision in $AuAu$ and
$CuCu$ collisions at $\sqrt{s} = 200$ GeV is computed in the framework of the
dual parton model, supplemented with final state interaction (comovers
interaction). For the latter we use the same value of the cross-section,
$\sigma_{co} = 0.65$ mb, which describes the anomalous $J/\psi$ suppression
observed at CERN-SPS energies. Several possibilities for the value of the
absorptive cross-section are considered. Shadowing is introduced in both the
comovers and the $J/\psi$ yields. A comparison with the results at CERN-SPS,
including a prediction for $InIn$ collisions, is also presented.


title: Merging gauge coupling constants without Grand Unification

abstract:
  The merging of the running couplings constants of the weak, strong, and
electromagnetic fields does not require the unification of these gauge fields
at high energy. It can, in fact, be the property of a general fermionic system
in which gauge bosons are not fundamental.


title:
Static QCD Potential at r < 1/Lambda_QCD: Perturbative expansion and
  operator-product expansion

abstract:
  We analyze the static QCD potential V_QCD(r) in the distance region 0.1 fm <
r < 1 fm using perturbative QCD and OPE as basic theoretical tools. We assemble
theoretical developments up to date and perform a solid and accurate analysis.
The analysis consists of 3 major steps: (I) We study large-order behavior of
the perturbative series of V_QCD(r) analytically. (II) In the frame of OPE, we
define two types of renormalization schemes for the leading Wilson coefficient.
(III) We compare numerically perturbative predictions of the Wilson coefficient
and lattice computations of V_QCD(r). We perform fits to simultaneously
determine non-perturbative contribution and the relation between lattice scale
and Lambda_MSbar. (Short version)


title:
Antiparticle to Particle Production Ratios in Hadron-Hadron and d-Au
  Collisions in the DPMJET-III Monte Carlo

abstract:
  To understand baryon stopping we analyse new RHIC and Fermilab data within
the framework of the multichain Monte Carlo DPMJET-III. The present
consideration is restricted to to hadron-hadron and d-Au collisions.


title:
Pion structure functions at 2 loops: final state interaction with
  spectator

abstract:
  Pion structure functions are considered in the framework of QCD sum rules at
the next to leading order. The 2-loop diargam, representing the gluon exchange
between the struck quark and spectator, is calculated for space-like pion
momentum p^2<0. After Borel transformation we obtain a leading twist correction
to the pion structure function, which does not violate Bjorken scaling. Partial
results can be used in the calculation of complete set of alpha_s corrections
to the pion structure functions, which may serve as an intitial condition in
the evolution equation. Probabilistic interpretation of the structure functions
is discussed.


title: Dijet Event Shapes as Diagnostic Tools

abstract:
  Event shapes have long been used to extract information about hadronic final
states and the properties of QCD, such as particle spin and the running
coupling. Recently, a family of event shapes, the angularities, has been
introduced that depends on a continuous parameter. This additional
parameter-dependence further extends the versatility of event shapes. It
provides a handle on nonperturbative power corrections, on non-global
logarithms, and on the flow of color in the final state.


title: Asymptotics of Feynman Diagrams and The Mellin-Barnes Representation

abstract:
  It is shown that the integral representation of Feynman diagrams in terms of
the traditional Feynman parameters, when combined with properties of the
Mellin--Barnes representation and the so called {\it converse mapping theorem},
provide a very simple and efficient way to obtain the analytic asymptotic
behaviours in both the large and small ratios of mass scales.


title:
Large Component QCD and Theoretical Framework of Heavy Quark Effective
  Field Theory

abstract:
  Based on a large component QCD derived directly from full QCD by integrating
over the small components of quark fields with $|{\bf p}| < E + m_Q$, an
alternative quantization procedure is adopted to establish a basic theoretical
framework of heavy quark effective field theory (HQEFT) in the sense of
effective quantum field theory. The procedure concerns quantum generators of
Poincare group, Hilbert and Fock space, anticommutations and velocity
super-selection rule, propagator and Feynman rules, finite mass corrections,
trivialization of gluon couplings and renormalization of Wilson loop. The
Lorentz invariance and discrete symmetries in HQEFT are explicitly illustrated.
Some new symmetries in the infinite mass limit are discussed. Weak transition
matrix elements and masses of hadrons in HQEFT are well defined to display a
manifest spin-flavor symmetry and $1/m_Q$ corrections. A simple trace
formulation approach is explicitly demonstrated by using LSZ reduction formula
in HQEFT, and shown to be very useful for parameterizing the transition form
factors via $1/m_Q$ expansion. As the heavy quark and antiquark fields in HQEFT
are treated on the same footing in a fully symmetric way, the quark-antiquark
coupling terms naturally appear and play important roles for simplifying the
structure of transition matrix elements, and for understanding the concept of
`dressed heavy quark' - hadron duality. In the case that the `longitudinal' and
`transverse' residual momenta of heavy quark are at the same order of power
counting, HQEFT provides a consistent approach for systematically analyzing
heavy quark expansion in terms of $1/m_Q$. Some interesting features in
applications of HQEFT to heavy hadron systems are briefly outlined.


title:
Non-interacting KN contribution in the QCD sum rule for the pentaquark
  Theta^+(1540)

abstract:
  We perform a QCD sum rule analysis for the pentaquark baryon Theta^+ with the
non-interacting $KN$ contribution treated carefully. The coupling of the
Theta^+ current to the $KN$ state is evaluated by applying the soft kaon
theorem and vacuum saturation. When using a five-quark current including scalar
and pseudo-scalar diquarks, the KN contribution turns out not to be very
important and the previous result of the negative parity Theta^+ is reproduced
again. The Borel analysis of the correlation function for Theta^+ with the KN
continuum states subtracted yields the mass of the J^P= 1/2^- Theta^+ around
1.5 GeV.


title:
Precise numerical evaluation of the two loop sunrise graph Master
  Integrals in the equal mass case

abstract:
  We present a double precision routine in Fortran for the precise and fast
numerical evaluation of the two Master Integrals (MIs) of the equal mass
two-loop sunrise graph for arbitrary momentum transfer in d=2 and d=4
dimensions. The routine implements the accelerated power series expansions
obtained by solving the corresponding differential equations for the MIs at
their singular points. With a maximum of 22 terms for the worst case expansion
a relative precision of better than a part in 10^{15} is achieved for arbitrary
real values of the momentum transfer.


title:
Electroweak corrections to charged-current e+e- --> 4 fermion processes
  - technical details and further results

abstract:
  The complete electroweak O(alpha) corrections have been calculated for the
charged-current four-fermion production processes e+e- --> nu_tau tau+ mu-
anti-nu_mu, u anti-d mu- anti-nu_mu, and u anti-d s anti-c. Here, technical
details of this calculation are presented. These include the algebraic
reduction of spinor chains to a few standard structures and the consistent
implementation of the finite width of the W boson. To this end, a
generalization of the complex-mass scheme to the one-loop level is proposed,
and the practical application of this method is described. Finally, the effects
of the complete O(alpha) corrections to various differential cross sections of
physical interest are discussed and compared to predictions based on the
double-pole approximation, revealing that the latter approximation is not
sufficient to fully exploit the potential of a future linear collider in an
analysis of W-boson pairs at high energies.


title:
Including the $\Delta(1232)$ resonance in baryon chiral perturbation
  theory

abstract:
  Baryon chiral perturbation theory with explicit $\Delta(1232)$ degrees of
freedom is considered. Using the extended on-mass-shell renormalization scheme,
a manifestly Lorentz-invariant effective field theory with a systematic power
counting is obtained. As applications we discuss the mass of the nucleon, the
pion-nucleon sigma term, and the pole of the $\Delta$ propagator.


title: The neural network approach to parton fitting

abstract:
  We introduce the neural network approach to global fits of parton
distribution functions. First we review previous work on unbiased
parametrizations of deep-inelastic structure functions with faithful estimation
of their uncertainties, and then we summarize the current status of neural
network parton distribution fits.


title: B meson wave function from the $B\to\gamma l\nu$ decay

abstract:
  We show that the leading-power $B$ meson wave function can be extracted
reliably from the photon energy spectrum of the $B\to\gamma l\nu$ decay up to
$O(1/m_b^2)$ and $O(\alpha_s^2)$ uncertainty, $m_b$ being the $b$ quark mass
and $\alpha_s$ the strong coupling constant. The $O(1/m_b)$ corrections from
heavy-quark expansion can be absorbed into a redefined leading-power $B$ meson
wave function. The two-parton $O(1/m_b)$ corrections cancel exactly, and the
three-parton $B$ meson wave functions turn out to contribute at $O(1/m_b^2)$.
The constructive long-distance contribution through the $B\to V\to\gamma$
transition, $V$ being a vector meson, almost cancels the destructive
$O(\alpha_s)$ radiative correction. Using models of the leading-power $B$ meson
wave function available in the literature, we obtain the photon energy spectrum
in the perturbative QCD framework, which is then compared with those from other
approaches.


title: Constraints on SUSY Lepton Flavour Violation by rare processes

abstract:
  We study the constraints on flavour violating terms in low energy SUSY coming
from several processes as li -> lj gamma, li -> lj lj lj and mu -> e in Nuclei.
We show that a combined analysis of the processes allows us to extract
additional information with respect to an individual analysis of all the
processes. In particular, it makes possible to put bounds on sectors previously
unconstrained by li -> lj gamma. We perform the analysis both in the mass
eigenstate and in the mass insertion approximations clarifying the limit of
applicability of these approximations.


title: Electroweak Evolution Equations

abstract:
  Enlarging a previous analysis, where only fermions and transverse gauge
bosons were taken into account, we write down infrared-collinear evolution
equations for the Standard Model of electroweak interactions computing the full
set of splitting functions. Due to the presence of double logs which are
characteristic of electroweak interactions (Bloch-Nordsieck violation), new
infrared singular splitting functions have to be introduced. We also include
corrections related to the third generation Yukawa couplings.


title:
B -> K1 gamma and tests of factorization for two-body non leptonic
  Bdecays with axial-vector mesons

abstract:
  The large branching ratio for B-> K1 gamma recently measured at Belle implies
a large B -> K1 transition form factor and large branching ratios for non
leptonic B decays involving an axial-vector meson. In this paper we present an
analysis of two-body B decays with an axial-vector meson in the final state
using naive factorization and the B -> K1 form factors obtained from the
measured radiative decays. We find that the predicted B -> J/psi K1 branching
ratio is in agreement with experiment. We also suggest that the decay rates of
B -> K1 pi, B -> a1 K and B -> b1 K could be used to test the factorization
ansatz.


title: Neutrino oscillations, a historical overview and its projection

abstract:
  Three topics are discussed : 1 Base fermions and scalars in SO10, 2 Neutrino
'mass from mixing' in vacuo and in matter, 3 Some perspectives .


title:
Quasi-thermal Universe and its implications for gravitino production,
  baryogenesis and dark matter

abstract:
  Under general circumstances full thermal equilibrium may not be established
for a long period after perturbative or non-perturbative decay of the inflaton
has completed. One can instead have a distribution of particles which is in
kinetic equilibrium and evolves adiabatically during this period.
Number-violating reactions which are required to establish chemical equilibrium
can become efficient only at much later times. We highlight some of the
striking consequences of such a quasi-thermal Universe. In particular, thermal
gravitino production yields {\it no bound} on the maximum temperature of the
primordial thermal bath alone. As another consequence, the lower bound on the
mass of the lightest right-handed (s)neutrino from thermal leptogenesis can be
$\gg 10^{9}$ GeV. Depending on the phase, a Wino or Higgsino considerably
lighter than TeV, or a Bino in the bulk region, can be a viable {\it thermal}
dark matter candidate. Finally the electroweak symmetry may never be restored
in the early Universe, therefore weakening any hopes of realizing a successful
electroweak baryogenesis.


title: Effective Supergravity from the Weakly Coupled Heterotic String

abstract:
  The motivation for Calabi-Yau-like compactifications of the weakly coupled
$E_8\otimes E_8$ heterotic string theory, its particle spectrum and the issue
of dilaton stabilization are briefly reviewed. Modular invariant models for
hidden sector condensation and supersymmetry breaking are described at the
quantum level of the effective field theory. Their phenomenological and
cosmological implications, including a possible origin for R-parity, are
discussed.


title: Saturation Physics and Deuteron--Gold Collisions at RHIC

abstract:
  We present a review of parton saturation/Color Glass Condensate physics in
the context of deuteron-gold ($d+Au$) collisions at RHIC. Color Glass
Condensate physics is a universal description of all high energy hadronic and
nuclear interactions. It comprises classical (McLerran-Venugopalan model and
Glauber-Mueller rescatterings) and quantum evolution (JIMWLK and BK equations)
effects both in small-$x$ hadronic and nuclear wave functions and in the high
energy scattering processes. Proton-nucleus (or $d+A$) collisions present a
unique opportunity to study Color Glass Condensate predictions, since many
relevant observables in proton-nucleus collisions are reasonably
well-understood theoretically in the Color Glass Condensate approach. In this
article we review the basics of saturation/Color Glass Condensate physics and
reproduce derivations of many important observables in proton
(deuteron)--nucleus collisions. We compare the predictions of Color Glass
physics to the data generated by $d+Au$ experiments at RHIC and observe an
agreement between the data and the theory, indicating that Color Glass
Condensate has probably been discovered at RHIC. We point out further
experimental measurements which need to be carried out to test the discovery.


title: Heavy quark potential and quarkonia dissociation rates

abstract:
  Quenched lattice data for the quark-antiquark interaction (in terms of heavy
quark free energies) in the color singlet channel at finite temperatures are
fitted and used within the nonrelativistic Schroedinger equation formalism to
obtain binding energies and scattering phase shifts for the lowest eigenstates
in the charmonium and bottomonium systems in a hot gluon plasma. The partial
dissociation rate due to the Bhanot-Peskin process is calculated using
different assumptions for the gluon distribution function, including free
massless gluons, massive gluons, and massive damped gluons. It is demonstrated
that a temperature dependent gluon mass has an essential influence on the heavy
quarkonia dissociation, but that this process alone is insufficient to describe
the heavy quarkonia dissociation rates.


title: Monochromatic neutrino beams

abstract:
  In the last few years spectacular results have been achieved with the
demonstration of non vanishing neutrino masses and flavour mixing. The ultimate
goal is the understanding of the origin of these properties from new physics.
In this road, the last unknown mixing [Ue3] must be determined. If it is proved
to be non-zero, the possibility is open for Charge Conjugation-Parity (CP)
violation in the lepton sector. This will require precision experiments with a
very intense neutrino source. Here a novel method to create a monochromatic
neutrino beam, an old dream for neutrino physics, is proposed based on the
recent discovery of nuclei that decay fast through electron capture. Such
nuclei will generate a monochromatic directional neutrino beam when decaying at
high energy in a storage ring with long straight sections. We also show that
the capacity of such a facility to discover new physics is impressive, so that
fine tuning of the boosted neutrino energy allows precision measurements of the
oscillation parameters even for a [Ue3] mixing as small as 1 degree. We can
thus open a window to the discovery of CP violation in neutrino oscillations.


title: The Last of the Finite Loop Amplitudes in QCD

abstract:
  We use on-shell recursion relations to determine the one-loop QCD scattering
amplitudes with a massless external quark pair and an arbitrary number (n-2) of
positive-helicity gluons. These amplitudes are the last of the unknown
infrared- and ultraviolet-finite loop amplitudes of QCD. The recursion
relations are similar to ones applied at tree level, but contain new
non-trivial features corresponding to poles present for complex momentum
arguments but absent for real momenta. We present the relations and the compact
solutions to them, valid for all n. We also present compact forms for the
previously-computed one-loop n-gluon amplitudes with a single negative helicity
and the rest positive helicity.


title: Kinetics of Oscillating Neutrinos

abstract:
  In the context of core-collapse supernovae, Strack and Burrows (Phys. Rev. D
71, 093004 (2005)) have recently developed an extension of the classical
Boltzmann kinetic formalism that retains all the standard neutrino oscillation
phenomenology, including resonant flavor conversion (the MSW effect), neutrino
self-interactions, and the interplay between neutrino-matter coupling and
flavor oscillations. In this thesis, I extend the Strack & Burrows formalism to
incorporate general relativity, spin degrees of freedom, and a possible
neutrino magnetic-moment/magnetic-field interaction.


title: Coherent lunar effect on solar neutrino

abstract:
  Coherent interaction of solar neutrino with the moon and its implication are
investigated. We solve the Dirac equation with the moon potential and show that
a phase shift of the neutrino wave function becomes almost one unit if the
neutrino penetrates the moon. Spatial interference is generated for the
neutrino wave packets during eclipse and possibility of observing interference
effect that is similar to that of a double slit experiment is pointed out.


title:
Predictions of pp, pbar p total cross section and rho ratio at LHC and
  cosmic-ray energies

abstract:
  We propose to use rich informations on the pp, pbar p total cross sections
sigma below N=10 GeV in order to predict the total cross section and rho ratio
at very high energies. Using the FESR as a constraint for high energy
parameters, we search for the simultaneous best fit to the data points of sigma
and rho ratio up to some energy (e.g., ISR, Tevatron) to determine the
high-energy parameters. We then predict sigma and rho in the LHC and
high-energy cosmic-ray regions. Using the data up to sqrt s =1.8 TeV(Tevatron),
we predict sigma(pp) and rho(pp) at the LHC energy(sqrt s = 14 TeV) as 106.3 +-
5.1(syst) +- 2.4(stat) mb and 0.126 +- 0.007(syst) +- 0.004(stat),
respectively. The predicted values of sigma in terms of the same parameters are
in good agreement with the cosmic-ray experimental data sample up to Plab =
10^(8--9) GeV by Block, Halzen, and Stanov.


title:
Light Composite Higgs from Higher Representations versus Electroweak
  Precision Measurements -- Predictions for LHC

abstract:
  We investigate theories in which the technifermions in higher dimensional
representations of the technicolor gauge group dynamically break the
electroweak symmetry of the standard model. For the two-index symmetric
representation of the gauge group the lowest number of techniflavors needed to
render the underlying gauge theory quasi conformal is two. We confront the
models with the recent electroweak precision measurements and demonstrate that
the two technicolor theory is a valid candidate for a dynamical breaking of the
electroweak symmetry. The electroweak precision measurements provide useful
constraints on the relative mass splitting of the new leptons needed to cure
the Witten anomaly. In the case of a fourth family of leptons with ordinary
lepton hypercharge the new heavy neutrino can be a natural candidate of cold
dark matter. We also propose theories in which the critical number of flavors
needed to enter the conformal window is higher than the one with fermions in
the two-index symmetric representation, but lower than in the walking
technicolor theories with fermions only in the fundamental representation of
the gauge group. Due to the near conformal/chiral phase transition, we show
that the composite Higgs is very light compared to the intrinsic scale of the
technicolor theory. For the two technicolor theory we predict the composite
Higgs mass not to exceed 150 GeV.


title: A Critical Study of the B -> K \pi Puzzle

abstract:
  In the light of new experimental results on B -> K pi decays, we critically
study the decay processes B -> K pi in a phenomenological way. Using the quark
diagram approach and the currently available data, we determine the allowed
values of the relevant theoretical parameters, corresponding to the electroweak
(EW) penguin, the color-suppressed tree contribution, etc. In order to find the
most likely values of the parameters in a statistically reliable way, we use
the chi^2 minimization technique. Our result shows that the current data for B
to K pi decays strongly indicate (large) enhancements of both the EW penguin
and the color-suppressed tree contributions. In particular, the
color-suppressed tree effect needs to be enhanced by about an order of
magnitude to fit the present data.


title: On the Ground State of Two Flavor Color Superconductor

abstract:
  The diquark condensate susceptibility in neutral color superconductor at
moderate baryon density is calculated in the frame of two flavor
Nambu-Jona-Lasinio model. When color chemical potential is introduced to keep
charge neutrality, the diquark condensate susceptibility is negative in the
directions without diquark condensate in color space, which may be regarded as
a signal of the instability of the conventional ground state with only diquark
condensate in the color 3 direction.


title: Time Series Analysis Methods Applied to the Super-Kamiokande I Data

abstract:
  The need to unravel modulations hidden in noisy time series of experimental
data is a well known problem, traditionally attacked through a variety of
methods, among which a popular tool is the so called Lomb-Scargle periodogram.
Recently, for a class of problems in the solar neutrino field, it has been
proposed an alternative maximum likelihood based approach, intended to overcome
some intrinsic limitations affecting the Lomb-Scargle implementation. This work
is focused to highlight the features of the likelihood methodology, introducing
in particular an analytical approach to assess the quantitative significance of
the potential modulation signals. As an example, the proposed method is applied
to the time series of the measured values of the 8B neutrino flux released by
the Super-Kamiokande collaboration, and the results compared with those of
previous analysis performed on the same data sets. It is also examined in
detail the comparison between the Lomb-Scargle and the likelihood methods,
giving in the appendix the complete demonstration of their close relationship.


title: The Fine-Tuning Problem in Little Higgs Models

abstract:
  Little Higgs models represent an alternative to Supersymmetry as a solution
to the Hierarchy Problem. After introducing the main physical ideas of these
models, we present the fine-tuning associated to the electroweak breaking in
Little Higgs scenarios. Taking into account the most general properties of this
scenarios and focusing on two representative ``Little Higgs'' models, we find
that the fine-tuning is much higher than suggested by the rough estimates
usually made. The main sources that increase the fine-tuning in these models
are identified, then they can be taken into account in order to construct a
successful model.


title: Discrete Symmetry and CP Phase of the Quark Mixing Matrix

abstract:
  A simple specific pattern of the two 3 X 3 quark mass matrices is proposed,
resulting in a prediction of the CP phase of the charged-current mixing matrix
V_CKM, i.e. sin 2 phi_1 (beta) = 0.733, which is in remarkable agreement with
data, i.e. sin 2 phi_1 = 0.728 +/- 0.056 +/- 0.023 from Belle and sin 2 beta =
0.722 +/- 0.040 +/- 0.023 from Babar. This pattern can be maintained by a
discrete family symmetry, an example of which is D_7, the symmetry group of the
heptagon.


title: Radiative Corrections to Bremsstrahlung in Radiative Return

abstract:
  Radiating a photon from the initial state provides a useful tool for studying
a range of low energy physics using a high-energy e+ e- accelerator. Accurate
results require careful calculation of the first order virtual photon
corrections. We compare exact results for initial state radiative corrections,
finding agreement to an order of 10^{-5} or better as a fraction of the Born
cross-section for most of the range of photon energies, at CMS energies
relevant in both high-energy collision and radiative return experiments.


title: Non-universality of transverse Coulomb exchange at small x

abstract:
  Within an explicit scalar QED model we compare, at fixed x << 1, the
leading-twist K_T-dependent `quark' distribution f_q(x, K_T) probed in deep
inelastic scattering and Drell-Yan production, and show that the model is
consistent with the universality of f_q(x, K_T). The extension of the model
from the aligned-jet to the 'symmetric' kinematical regime reveals interesting
properties of the physics of Coulomb rescatterings when comparing DIS and DY
processes. At small x the transverse momentum <k_T^2> induced by multiple
scattering on a single centre is process dependent, as well as the transverse
momentum broadening occurring in collisions on a finite size nuclear target.


title: Screening of Dirac flavor structure in the seesaw and neutrino mixing

abstract:
  We consider the mechanism of screening of the Dirac flavor structure in the
context of the double seesaw mechanism. As a consequence of screening, the
structure of the light neutrino mass matrix, m_\nu, is determined essentially
by the structure of the (Majorana) mass matrix, M_S, of new super-heavy (Planck
scale) neutral fermions S. We calculate effects of the renormalization group
running in order to investigate the stability of the screening mechanism with
respect to radiative corrections. We find that screening is stable in the
supersymmetric case, whereas in the standard model it is unstable for certain
structures of M_S. The screening mechanism allows us to reconcile the
(approximate) quark-lepton symmetry and the strong difference of the mixing
patterns in the quark and lepton sectors. It opens new possibilities to explain
a quasi-degenerate neutrino mass spectrum, special ``neutrino'' symmetries and
quark-lepton complementarity. Screening can emerge from certain flavor
symmetries or Grand Unification.


title:
Reduction of Charm Quark Mass Scheme Dependence in $\bar B \to X_s
  \gamma$ at the NNLL Level

abstract:
  The uncertainty of the theoretical prediction of the $\bar B \to X_s \gamma$
branching ratio at NLL level is dominated by the charm mass renormalization
scheme ambiguity. In this paper we calculate those NNLL terms which are related
to the renormalization of $m_c$, in order to get an estimate of the
corresponding uncertainty at the NNLL level. We find that these terms
significantly reduce (by typically a factor of two) the error on ${BR}(\bar B
\to X_s \gamma)$ induced by the definition of $m_c$. Taking into account the
experimental accuracy of around 10% and the future prospects of the $B$
factories, we conclude that a NNLL calculation would increase the sensitivity
of the observable $\bar B \to X_s \gamma$ to possible new degrees of freedom
beyond the SM significantly.


title: The electron energy spectrum in muon decay through O(alpha^2)

abstract:
  We compute the complete O(alpha^2) QED corrections to the electron energy
spectrum in unpolarized muon decay, including the full dependence on the
electron mass. Our calculation reduces the theoretical uncertainty on the
electron energy spectrum well below 10^{-4}, the precision anticipated by the
TWIST experiment at TRIUMF, which is currently performing this measurement. For
this calculation, we extend techniques we have recently developed for
performing next-to-next-to-leading order computations to handle the decay
spectra of massive particles. Such an extension enables further applications to
precision predictions for b, t, and Higgs differential decay rates.


title:
Non-Fermi Liquid Behavior Induced by Resonant Diquark-pair Scattering in
  Heated Quark Matter

abstract:
  We show how the quasiparticle picture of quarks changes near but above the
critical temperature T_c of the color-superconducting phase transition in the
heated quark matter. We demonstrate that a non-Fermi liquid behavior of the
matter develops drastically when the diquark coupling constant is increased
owing to the coupling of the quark with the pairing soft mode: We clarify that
the depression and eventually the appearance of a gap structure in the spectral
function as well as the anomalous quark dispersion relation of the quark can be
understood in terms of the resonant scattering between the incident quark and a
particle near the Fermi surface to make the pairing soft mode.


title: Towards a Precision Determination of alpha in B \to pi pi Decays

abstract:
  An assumption of isospin symmetry permits the determination of sin(2 alpha)
from the experimental study of B\to pi pi decays. Isospin, however, is merely
an approximate symmetry; its breaking predicates a theoretical systematical
error sigma_\alpha^{\rm IB} in the extraction of alpha. We focus on the impact
of \pi^0-\eta,\eta^\prime mixing, as well as the manner in which it is amenable
to empirical constraint, and determine that \sigma_\alpha^{\rm IB} can
potentially be controlled to {\cal O}(1^\circ).


title: Anomalous Axion Interactions and Topological Currents in Dense Matter

abstract:
  Recently an effective Lagrangian for the interactions of photons,
Nambu-Goldstone bosons and superfluid phonons in dense quark matter has been
derived using anomaly matching arguments. In this paper we illuminate the
nature of certain anomalous terms in this Lagrangian by an explicit microscopic
calculation. We also generalize the corresponding construction to introduce the
axion field. We derive an anomalous axion effective Lagrangian describing the
interactions of axions with photons and superfluid phonons in the dense matter
background. This effective Lagrangian, among other things, implies that an
axion current will be induced in the presence of magnetic field. We speculate
that this current may be responsible for the explanation of neutron star kicks.


title: Results from Lattice QCD

abstract:
  I present our recent results on the critical end point in the \mu_B-T phase
diagram of QCD with two flavours of light dynamical quarks and compare them
with similar results from other groups. Implications for a possible energy scan
at the RHIC are discussed. I also comment briefly on the new results of great
relevance to heavy ion collisions from finite temperature lattice QCD
simulations on speed of sound, specific heat and on the fate of J/\psi.


title:
Collider phenomenology of Higgs bosons in Left-Right symmetric
  Randall-Sundrum models

abstract:
  We investigate the collider phenomenology of a left-right symmetric
Randall-Sundrum model with fermions and gauge bosons in the bulk. We find that
the model is allowed by precision electroweak data as long as the ratio of the
(unwarped) Higgs vev to the curvature scale is $v/k \le 1/4$. In that region
there can be substantial modifications to the Higgs properties. In particular,
the couplings to $WW$ and $ZZ$ are reduced, the coupling to gluons is enhanced,
and the coupling to $\gamma\gamma$ can receive shifts in either direction. The
Higgs mass bound from LEP II data can potentially be relaxed to $m_H \gtrsim
80$ GeV.


title:
Corrections to sin(2 beta) from CP asymmetries in B^0 ->
  (pi^0,rho^0,eta,eta^',omega,phi) K_S decays

abstract:
  Neglecting smaller amplitudes the time-dependent CP asymmetry in
penguin-dominated b -> s q \bar q transitions (such as B -> phi K_S) is
expected to equal sin(2 beta), an expectation not borne out by the present
average experimental data. I compute and discuss the correction due to the
smaller amplitudes in the framework of QCD factorization.


title: Cosmological Family Asymmetry and CP violation

abstract:
  We discuss how the cosmological baryon asymmetry can be achieved by the
lepton family asymmetries of heavy Majorana neutrino decays and they are
related to CP violation in neutrino oscillation, in the minimal seesaw model
with two heavy Majorana neutrinos. We derive the most general formula for CP
violation in neutrino oscillation in terms of the heavy Majorana masses and
Yukawa mass term. It is shown that the formula is very useful to classify
several models in which $e-$, $\mu-$ and $\tau-$leptogenesis can be separately
realized and to see how they are connected with low energy CP violaton. To make
the models predictive, we take texture with two zeros in the Dirac neutrino
Yukawa matrix. In particular, we find some interesting cases in which CP
violation in neutrino oscillation can happen while lepton family asymmetries do
not exist at all. On the contrary, we can find $e-$, $\mu-$ and
$\tau-$leptogenesis scenarios in which the cosmological CP violation and low
energy CP violation measurable via neutrino oscillations are very closely
related to each other. By determining the allowed ranges of the parameters in
the models, we predict the sizes of CP violation in neutrino oscillation and
$|V_{e3}^{MNS}|$. Finally, the leptonic unitarity triangles are reconstructed.


title:
Radiative corrections in weak semi-leptoni processes at low energy: a
  two-step matching determination

abstract:
  We focus on the chiral Lagrangian couplings describing radiative corrections
to weak semi-leptonic decays and relate them to the decay amplitude of a
lepton, computed by Braaten and Li at one loop in the Standard Model. For this
purpose, we follow a two-step procedure. A first matching, from the Standard
Model to Fermi theory, yields a relevant set of counterterms. The latter are
related to chiral couplings thanks to a second matching, from Fermi theory to
the chiral Lagrangian, which is performed using the spurion method. We show
that the chiral couplings of physical relevance obey integral representations
in a closed form, expressed in terms of QCD chiral correlators and vertex
functions. We deduce exact relations among the couplings, as well as numerical
estimates which go beyond the usual $\log(M\_Z/M\_\rho)$ approximation.


title: Decoupling, lepton flavour violation and leptogenesis

abstract:
  Several classes of neutrino mass models, which can naturally account for
hierarchical masses and the bi-large pattern of neutrino mixing, are
constructed from a bottom-up perspective based on the idea of decoupling of one
right-chiral neutrino from the seesaw mechanism. The interplay between the
predictions for the lepton-flavour violation in the MSSM with universal soft
masses and for leptogenesis is studied. In particular, classes of neutrino mass
models in which successful leptogenesis implies BR(mu->e gamma) potentially
observable in upcoming experiments are identified.


title:
Analytical formulas for elastic neutrino-fermion scattering cross
  sections

abstract:
  In this paper, analytical formulas for elastic neutrino-fermion scattering
cross sections are presented. These are evaluated in the limit where the
neutrino mass is neglible compared to the incoming momentum. The fermion mass
is taken into account, however, yielding a good approximation to realistic
scattering reactions. The intended level of readership is for
undergraduates/graduates in the fields of relativistic quantum mechanics and
quantum field theory. In addition to a detailed and pedagogical derivation of
the analytical expressions, numerical results are also provided for $f=e,n,p$.


title: Hadronic Modes and Quark Properties in the Quark-Gluon Plasma

abstract:
  Based on interaction potentials between a heavy quark and antiquark as
extracted from recent QCD lattice calculations, we set up a Brueckner-type
many-body scheme to study the properties of light (anti-) quarks in a
Quark-Gluon Plasma at moderate temperatures, $T\simeq$ 1-2 $T_c$. The
quark-antiquark $T$-matrix, including both color-singlet and -octet channels,
and corresponding quark self-energies and spectral functions are calculated
self-consistently. The repulsive octet potential induces quasiparticle masses
of up to 150 MeV, whereas the attractive color-singlet part generates resonance
structures in the $q$-$\bar q$ $T$-matrix, which in turn lead to quasiparticle
widths of $\sim$200 MeV. This corresponds to scattering rates of $\sim$1
fm$^{-1}$ and may reflect liquid-like properties of the system.


title:
KamLAND neutrino spectra in energy and time: Indications for reactor
  power variations and constraints on the georeactor

abstract:
  The Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND) is sensitive
to the neutrino event spectrum from (mainly Japanese) nuclear reactors in both
the energy domain and the time domain. While the energy spectrum of KamLAND
events allows the determination of the neutrino oscillation parameters, the
time spectrum can be used to monitor known and unknown neutrino sources. By
using available monthly-binned data on event-by-event energies in KamLAND and
on reactor powers in Japan, we perform a likelihood analysis of the neutrino
event spectra in energy and time, and find significant indications in favor of
time variations of the known reactor sources, as compared with the hypothetical
case of constant reactor neutrino flux. We also find that the KamLAND data
place interesting upper limits on the power of a speculative nuclear reactor
operating in the Earth's core (the so-called georeactor); such limits are
strengthened by including solar neutrino constraints on the neutrino mass and
mixing parameters. Our results corroborate the standard interpretation of the
KamLAND signal as due to oscillating neutrinos from known reactor sources.


title: Magnetic moment versus tensor charge

abstract:
  We express the baryon magnetic moments in terms of the baryon tensor charges,
considering the quarks as relativistic interacting objects. Once tensor charges
get measured accurately, the formula for the baryon magnetic moment will serve
to extract precise information on the quark anomalous magnetic moment, the
quark effective mass and the ratio of the quark constituent mass to the quark
effective mass. The analogous formula for the baryon electric dipole moment is
of no great use as it gets eventually sizable contributions from various CP-
violating sources not necessary associated to the quark electric dipole moment.


title:
Density resummation of perturbation series in a pion gas to leading
  order in chiral perturbation theory

abstract:
  The mean field (MF) approximation for the pion matter, being equivalent to
the leading ChPT order, involves no dynamical loops and, if self-consistent,
produces finite renormalizations only. The weight factor of the Haar measure of
the pion fields, entering the path integral, generates an effective Lagrangian
$\delta \mathcal{L}_{H}$ which is generally singular in the continuum limit.
There exists one parameterization of the pion fields only, for which the weight
factor is equal to unity and $\delta \mathcal{L}_{H}=0$, respectively. This
unique parameterization ensures selfconsistency of the MF approximation. We use
it to calculate thermal Green functions of the pion gas in the MF approximation
as a power series over the temperature. The Borel transforms of thermal
averages of a function $\mathcal{J}(\chi ^{\alpha}\chi ^{\alpha})$ of the pion
fields $\chi ^{\alpha}$ with respect to the scalar pion density are found to be
$\frac{2}{\sqrt{\pi}}\mathcal{J}(4t)$. The perturbation series over the scalar
pion density for basic characteristics of the pion matter such as the pion
propagator, the pion optical potential, the scalar quark condensate
$<{\bar{q}}q>$, the in-medium pion decay constant ${\tilde{F}}$, and the
equation of state of pion matter appear to be asymptotic ones. These series are
summed up using the contour-improved Borel resummation method. The quark scalar
condensate decreases smoothly until $T_{max}\simeq 310$ MeV. The temperature
$T_{max}$ is the maximum temperature admissible for thermalized non-linear
sigma model at zero pion chemical potentials. The estimate of $T_{max}$ is
above the chemical freeze-out temperature $T\simeq 170$ MeV at RHIC and above
the phase transition to two-flavor quark matter $T_{c} \simeq 175$ MeV,
predicted by lattice gauge theories.


title: Proton Lifetime from SU(5) in Extra Dimensions

abstract:
  We perform a detailed analysis in order to estimate the proton lifetime in
the context of simple supersymmetric SU(5) model with an extradimension
compactified on the orbifold S^1/(Z_2 x Z_2').


title:
Some Global Aspects of Gauge Anomalies of Semisimple Gauge Groups and
  Fermion Generations in GUT and Superstring Theories

abstract:
  We study more extensively and completely for global gauge anomalies with some
semisimple gauge groups as initiated in ref.1. A detailed and complete proof or
derivation is provided for the Z_2 global gauge anomaly given in ref.1 for a
gauge theory with the semisimple gauge group SU(2)\times SU(2)\times SU(2) in
D=4 dimensions and Weyl fermions in the irreducible representation (IR)
\omega=(2,2,2) with 2 denoting the corresponding dimensions. This Z_2 anomaly
was used in the discussions related to generic SO(10) and supersymmetric SO(10)
unification theories^1 for the total generation numbers of fermions and mirror
fermions. Our result^1 that the global anomaly coefficient formula is given by
A(\omega)=exp[i{\pi}Q_2(\Box)]=-1 in this case with Q_2(\Box) being the Dynkin
index for SU(8) in the fundamental IR (\Box)=(8) is also discussed, and as
shown by our results^1 that the semisimple gauge transformations collectively
may have physical consequences which do not correspond to successive simple
gauge transformations. The similar result given in ref.1 for the Z_2 global
gauge anomaly of gauge group SU(2)\times SU(2) is also discussed. We also give
a complete proof for some relevent topological results. Gauge anomalies for the
relevant semisimple gauge groups are also briefly discussed in higher
dimensions, especially for self-contragredient representations, with
discussions involving trace identities relating to ref.14. We also remark the
connection of our results and discussions to the total generation numbers in
relevant theories.


title:
NLO Supersymmetric QCD Corrections to $t \bar t h^0$ Associated
  Production at Hadron Colliders

abstract:
  We calculate NLO QCD corrections to the lightest neutral Higgs boson
production associated with top quark pair at hadron colliders in the minimal
supersymmetric standard model(MSSM). Our calculation shows that the total QCD
correction significantly reduces its dependence on the
renormalization/factorization scale. The relative correction from the SUSY QCD
part approaches to be a constant, if either $M_S$ or $m_{\tilde{g}}$ is heavy
enough. The corrections are generally moderate(in the range of few percent to
20%) and under control in most of the SUSY parameter space. The relative
correction is obviously related to $m_{\tilde{g}}$, $A_t$ and $\mu$, but not
very sensitive to $\tan\beta$, $M_S$ at both the Tevatron and the LHC with our
specified parameters.


title:
Spin rotation and oscillations for high energy particles in a crystal
  and possibility to measure the quadrupole moments and tensor polarizabilities
  of elementary particles and nuclei

abstract:
  It is shown that particle motion in a bent (straight) crystal is accompanied
by particle spin rotation and oscillations that allows to measure the tensor
electric and magnetic polarizabilities of nuclei and elementary particles. It
is shown that channelling of particles in either straight or bent crystal with
the polarized nuclei could be used both to analyze polarization of high energy
particles and polarize them.


title: Proton-nucleus scattering and cross section fluctuations at RHIC and LHC

abstract:
  We consider high-energy proton-heavy nucleus scattering within the framework
of the Glauber-Gribov approximation and taking into account cross section
fluctuations. Fixing parameters of the model for cross section fluctuations by
the available data, we make predictions for the total, elastic and coherent
diffractive dissociation proton-nucleus cross sections for the RHIC and LHC
energy range. We predict a strong change of the A-dependence of diffraction
dissociation from A^{0.42} at RHIC energies to A^{0.27} at LHC energies.
  Based on the obtained results, we discuss the approach of the interactions to
the black body (unitarity) limit. We estimate the electromagnetic contribution
to coherent pA diffraction and find that it dominates the coherent diffractive
cross section on heavy nuclear targets in the RHIC and LHC kinematics.


title:
Nambu Jona-Lasinio Model of \bar q q Bose Einstein Condensation and
  pseudogap phase

abstract:
  We show the existence of a pseudogap phase in the Nambu Jona-Lasinio model of
quark interactions. In the pseudogap phase chiral symmetry is restored but
q\bar q pseudoscalar mesons still exist and they are massive. Such a behavior
is intermediate between a BCS superconductor and a Bose Einstein Condensate. We
suggest the relevance of this phenomenon for an understanding of recent lattice
QCD and experimental data.


title: Nucleon-Nucleon Bremsstrahlung emission of massive Axion

abstract:
  We consider the problem of axion production by bremsstrahlung emission in a
nuclear medium. The usual assumption of a massless axion is replaced by more
general hypotheses, so that we can describe the emission process for axions
with mass up to a few MeV. We point out that in certain physical situations the
contribution from non-zero mass is non-negligible. In particular, in the
mechanism for the production of Gamma Ray Bursts via emission of heavy axions
the axion mass m_a ~ 1MeV is comparable with the temperature of the nuclear
medium and thus can not be disregarded. Looking at our results we find, in
fact, a fairly considerable reduction of the axion luminosity in that
mechanism.


title:
Hadronic mass and q^2 moments of charmless semileptonic B decay
  distributions

abstract:
  We report OPE predictions for hadronic mass and q^2 moments in inclusive
semileptonic B decays without charm, taking into account experimental cuts on
the charged lepton energy and on the hadronic invariant mass, and address the
related theoretical uncertainty.


title: Neutrino dispersion in external magnetic fields

abstract:
  We calculate the neutrino self-energy operator Sigma (p) in the presence of a
magnetic field B. In particular, we consider the weak-field limit e B <<
m_\ell^2, where m_\ell is the charged-lepton mass corresponding to the neutrino
flavor \nu_\ell, and we consider a "moderate field" m_\ell^2 << e B << m_W^2.
Our results differ substantially from the previous literature. For a moderate
field, we show that it is crucial to include the contributions from all Landau
levels of the intermediate charged lepton, not just the ground-state. For the
conditions of the early universe where the background medium consists of a
charge-symmetric plasma, the pure B-field contribution to the neutrino
dispersion relation is proportional to (e B)^2 and thus comparable to the
contribution of the magnetized plasma.


title: Majorana Neutrino Masses from Flavor Symmetries

abstract:
  In this talk we discuss the implications of the Minimal Supersymmetric
Standard Model augmented by a single U(1) anomalous family symmetry for
neutrino masses and mixing angles. The left-handed neutrino states are provided
with Majorana masses through a dimension-five operator in the absence of right
handed neutrino components. Assuming symmetric lepton mass matrices, the model
predicts inverse hierarchical neutrino mass spectrum, theta_13=0 and large
mixing while at the same time it provides acceptable mass matrices for the
charged fermions.


title: K -> pi nu nubar and R-parity violating supersymmetry

abstract:
  Motivated by the recent experimental data of the E787, E949 and E865
collaborations and by the difference between the standard model (SM) prediction
and data, we consider in detail R-parity violating (RPV) supersymmetric
contributions to K -> pi nu nubar. The theoretical cleaness of this decay
constitutes a useful way to provide constraints, independent of long distance
effects. Including the possiblity of interferences between one-loop R-parity
conserving (RPC) supersymmetry and tree-level RPV supersymmetric contributions,
our results allow to improve the limits on R-parity violating couplings with
respect to previous analyses.


title: Classical chromodynamics and heavy ion collisions

abstract:
  This paper is a slightly modified version of the introductory part of a
doctoral dissertation also containing the articles hep-ph/0303076,
hep-ph/0409328 and hep-ph/0409058. The paper focuses on the calculation of
particle production in a relativistic heavy ion collision using the
McLerran-Venugopalan model. The main part of the paper summarizes the
background of these numerical calculations. First we relate this calculation of
the initial stage af a heavy ion collision to our understanding of the whole
collision process. Then we discuss the saturation physics of the small x
wavefunction of a hadron or a nucleus. The classical field model of Kovner,
McLerran and Weigert is then introduced before moving to discuss the numerical
algorithms used to compute gluon and quark pair production in this model.
Finally we shortly review the results on gluon and quark-antiquark production
obtained in the three articles mentioned above.


title: Renormalization Group and Grand Unification with 331 Models

abstract:
  By making a renormalization group analysis we explore the possibility of
having a 331 model as the only intermediate gauge group between the standard
model and the scale of unification of the three coupling constants. We shall
assume that there is no necessarily a group of grand unification at the scale
of convergence of the couplings. With this scenario, different 331 models and
their corresponding supersymmetric versions are considered, and we find the
versions that allow the symmetry breaking described above. Besides, the allowed
interval for the 331 symmetry breaking scale, and the behavior of the running
coupling constants are obtained. It worths saying that some of the
supersymmetric scenarios could be natural frameworks for split supersymmetry.
Finally, we look for possible 331 models with a simple group at the grand
unification scale, that could fit the symmetry breaking scheme described above.


title:
The photon energy spectrum in B-> X_s + \gamma in perturbative QCD
  through O(\alpha_s^2)

abstract:
  We derive the dominant part of the O(\alpha_s^2) correction to the photon
energy spectrum in the inclusive decay B-> X_s+gamma. The detailed knowledge of
the spectrum is important for relating the theoretical calculations of the B->
X_s + \gamma decay rate and the experimental measurements where a cut on the
photon energy is applied. In addition, moments of the photon energy spectrum
are used for the determination of the b-quark mass and other fundamental
parameters of heavy quark physics. Our calculation reduces the theoretical
uncertainty associated with uncalculated higher orders effects and shows that,
for B-> X_s+\gamma, QCD radiative corrections to the photon energy spectrum are
under theoretical control.


title: Impact of A0 on the mSUGRA parameter space

abstract:
  In mSUGRA models the lightest supersymmetric particle (assumed to be the
lightest neutralino) provides an excellent cold dark matter (CDM) candidate.
The supersymmetric parameter space is significantly reduced, if the limits on
the CDM relic density, obtained from WMAP data, are used. Assuming a vanishing
trilinear scalar coupling A0 and fixed values of tan(beta), these limits result
in narrow lines of allowed regions in the m0-m12 plane, the so called WMAP
strips. In this analysis the trilinear coupling A0 has been varied within
+/-4TeV resulting in largely extended areas in the m0-m12 plane which are no
longer excluded.


title: Pair production in inhomogeneous fields

abstract:
  We employ the recently developed worldline numerics, which combines
string-inspired field theory methods with Monte-Carlo techniques, to develop an
algorithm for the computation of pair-production rates in scalar QED for
inhomogeneous background fields. We test the algorithm with the classic Sauter
potential, for which we compute the local production rate for the first time.
Furthermore, we study the production rate for a superposition of a constant E
field and a spatially oscillating field for various oscillation frequencies.
Our results reveal that the approximation by a local derivative expansion fails
already for frequencies small compared to the electron mass scale, whereas for
strongly oscillating fields a derivative expansion for the averaged field
represents an acceptable approximation. The worldline picture makes the
nonlocal nature of pair production transparent and facilitates a profound
understanding of this important quantum phenomenon.


title: Lambda-Baryon Production in pi(+-)n Interactions

abstract:
  The process of Lambda-baryon production in pi-p collisions is considered. The
contribution of the string-junction mechanism to the strange baryon production
in meson-baryon scattering is anlysed. The results of numerical calculations in
the framework of the Quark-Gluon String model are in reasonable agreement with
the data.


title: The high energy asymptotics of scattering processes in QCD

abstract:
  High energy scattering in the QCD parton model was recently shown to be a
reaction-diffusion process, and thus to lie in the universality class of the
stochastic Fisher-Kolmogorov-Petrovsky-Piscounov equation. We recall that the
latter appears naturally in the context of the parton model. We provide a
thorough numerical analysis of the mean field approximation, given in QCD by
the Balitsky-Kovchegov equation. In the framework of a simple stochastic toy
model that captures the relevant features of QCD, we discuss and illustrate the
universal properties of such stochastic models. We investigate in particular
the validity of the mean field approximation and how it is broken by
fluctuations. We find that the mean field approximation is a good approximation
in the initial stages of the evolution in rapidity.


title: Pion Parton Distributions in a non local Lagrangian

abstract:
  We use phenomenological nonlocal Lagrangians, which lead to non trivial forms
for the quark propagator, to describe the pion. We define a procedure, based on
the Dyson-Schwinger equations, for the calculation of the pion parton
distributions at low Q^2. The obtained parton distributions fulfill all the
wishful properties. Using a convolution approach we incorporate the composite
character of the constituent quarks in the formalism. We evolve, using the
Renormalization Group, the calculated parton distributions to the experimental
scale and compare favorably with the data and draw conclusions.


title: MSSM Electroweak Baryogenesis and Flavour Mixing in Transport Equations

abstract:
  We make use of the formalism developed in Ref. [1], and calculate the
chargino mediated baryogenesis in the Minimal Supersymmetric Standard Model.
The formalism makes use of a gradient expansion of the Kadanoff-Baym equations
for mixing fermions. For illustrative purposes, we first discuss the
semiclassical transport equations for mixing bosons in a space-time dependent
Higgs background. To calculate the baryon asymmetry, we solve a standard set of
diffusion equations, according to which the chargino asymmetry is transported
to the top sector, where it biases sphaleron transitions. At the end we make a
qualitative and quantitative comparison of our results with the existing work.
We find that the production of the baryon asymmetry of the Universe by
CP-violating currents in the chargino sector is strongly constrained by
measurements of electric dipole moments.


title: Invisible Higgs in large extra dimensions

abstract:
  We discuss the possibility of detecting a Higgs boson in electron-positron
collider experiments if large extra dimensions are realized in nature. In such
a case, the Higgs boson can decay invisibly by oscillating into a graviscalar
Kaluza-Klein (KK) tower. We show that the search for such a Higgs at an $e^+
e^-$ linear collider entails more complications than are usually thought of in
relation to an invisibly decaying Higgs.


title: Supersymmetry and the MSSM: An Elementary Introduction

abstract:
  These notes are an expanded version of a short course of lectures given for
graduate students in particle physics at Oxford. The level was intended to be
appropriate for students in both experimental and theoretical particle
physics.The purpose is to present an elementary and self-contained introduction
to SUSY that follows on, relatively straightforwardly, from graduate-level
courses in relativistic quantum mechanics and introductory quantum field
theory. The notation adopted, at least initially, is one widely used in RQM
courses, rather than the `spinor calculus' (dotted and undotted indices)
notation found in most SUSY sources, though the latter is introduced in
optional Asides. There is also a strong preference for a `do-it-yourself'
constructive approach, rather than for a top-down formal deductive treatment.
The main goal is to provide a practical understanding of how the softly broken
MSSM is constructed. Relatively less space is devoted to phenomenology, though
simple `classic' results are covered, including gauge unification, the bound on
the mass of the lightest Higgs boson, and sparticle mixing. By the end of the
course students (readers) should be provided with access to the contemporary
phenomenological literature.


title: Quark Spectrum near Chiral Transition Points

abstract:
  Near the critical temperature of the chiral phase transition, a collective
excitation due to fluctuation of the chiral order parameter appears. We
investigate how it affects the quark spectrum near but above the critical
temperature. The calculated spectral function has many peaks. We show this
behavior can be understood in terms of resonance scatterings of a quark off the
collective mode.


title:
Infrared renormalons and the relations between the Gross-Llewellyn Smith
  and the Bjorken polarized and unpolarized sum rules

abstract:
  It is demonstrated that the infrared renormalon calculus indicates that the
QCD theoretical expressions for the Gross-Llewelln Smith sum rules and for the
Bjorken polarized and unpolarized ones contain an identical negative twist-4
1/Q^2 correction. This observation is supported by the consideration of the
results of calculations of the corresponding twist-4 matrix elements. Together
with the indication of the similarity of perturbative QCD corrections to these
three sum rules, this observation leads to simple new theoretical relations
between the Gross-Llewellyn Smith and Bjorken polarized and unpolarized sum
rules in the energy region $Q^2\geq 1 GeV^2$. The validity of this relation is
checked using concrete experimental data for the Gross-Llewellyn Smith and
Bjorken polarized sum rules


title: Casimir effect in a six-dimensional vortex scenario

abstract:
  Recently Randjbar-Daemi and Shaposhnikov put forward a 4-dimensional
effective QED coming from a Nielsen-Olesen vortex solution of the abelian Higgs
model with fermions coupled to gravity in D=6. However, exploring possible
physical consequences of such an effective QED was left open. In this letter we
study the corresponding effective Casimir effect. We find that the extra
dimensions yield fifth and third inverse powers in the separation between
plates for the modified Casimir force which are in conflict with known
experiments, thus reducing the phenomenological viability of the model.


title: Upper Bounds on Rare K and B Decays from Minimal Flavour Violation

abstract:
  We study the branching ratios of rare K and B decays in models with minimal
flavour violation, using the presently available information from the universal
unitarity triangle analysis and from the measurements of Br(B -> X_s gamma),
Br(B -> X_s l^+l^-) and Br(K^+ -> pi^+ nu nubar). We find the following upper
bounds: Br(K^+ -> pi^+ nu nubar)< 11.9 10^{-11}, Br(K_L -> pi^0 nu nubar)< 4.6
10^{-11}, Br(K_L -> mu mubar)_{SD}< 1.4 10^{-9}, Br(B -> X_s nu nubar)< 5.2
10^{-5}, Br(B -> X_d nu nubar)< 2.2 10^{-6}, Br(B_s -> mu mubar)< 7.4 10^{-9},
Br(B_d -> mu mubar)< 2.2 10^{-10} at 95 % probability. We analyze in detail
various possible scenarios with positive or negative interference of Standard
Model and New Physics contributions, and show how an improvement of
experimental data corresponding to the projected 2010 B factory integrated
luminosities will allow to disentangle and test these different possibilities.
Finally, anticipating that subsequently the leading role in constraining this
kind of new physics will be taken over by the rare decays K^+ -> pi^+ nu nubar,
K_L -> pi^0 nu nubar and B_{s,d} -> mu mubar, that are dominated by the Z^0
-penguin function C, we also present plots for several branching ratios as
functions of C . We point out an interesting triple correlation between K^+ ->
pi^+ nu nubar, B -> X_s gamma and B -> X_s l^+l^- present in MFV models.


title: Antenna Subtraction at NNLO

abstract:
  The computation of exclusive QCD jet observables at higher orders requires a
method for the subtraction of infrared singular configurations arising from
multiple radiation of real partons. We present a subtraction scheme relevant
for NNLO perturbative calculations in $e^+e^- \to $ jets. The building blocks
of the scheme are antenna functions derived from the matrix elements for
tree-level $1\to 3$ and $1 \to 4$ and one-loop $1 \to 3$ processes. By
construction, these building blocks have the correct infrared behaviour when
one or two particles are unresolved. At the same time, their integral over the
antenna phase space is straightforward. As an example of how to use the scheme
we compute the NNLO contributions to the subleading colour QED-like
contribution to $e^+e^- \to 3$ jets.
  To illustrate the application of NNLO antenna subtraction for different
colour structures, we construct the integrated forms of the subtraction terms
needed for the five-parton and four-parton contributions to $e^+e^- \to 3$ jets
at NNLO in all colour factors, and show that their infrared poles cancel
analytically with the infrared poles of the two-loop virtual correction to this
observable.


title:
Why black hole production in scattering of cosmic ray neutrinos is
  generically suppressed

abstract:
  It has been argued that neutrinos originating from ultra-high energy cosmic
rays produce black holes deep in the atmosphere in models with TeV-scale
quantum gravity. Such black holes would initiate quasi-horizontal showers of
particles far above the standard model rate, so that the Auger Observatory
would observe hundreds of black hole events. This would provide the first
opportunity for experimental study of microscopic black holes. However, any
phenomenologically viable model with a low scale of quantum gravity must
explain how to preserve protons from rapid decay mediated by virtual black
holes. We argue that unless this is accomplished by the gauging of baryon or
lepton number, the suppression of proton decay will also suppress quantum
gravity mediated lepton-nucleon scattering, and hence black hole production by
scattering of ultra-high energy cosmic ray neutrinos in the atmosphere. We
demonstrate this explicitly for the split fermion solution to the problem of
fast proton decay.


title:
The flavor physics in unified gauge theory from an S_3*P discrete
  symmetry

abstract:
  We investigate the phenomenological implication of the discrete symmetry
S_3*P on flavor physics in SO(10) unified theory. We construct a minimal
renormalizable model which reproduces all the masses and mixing angle of both
quarks and leptons. As usually the SO(10) symmetry gives up to relations
between the down sector and the charged lepton masses. The underlining discrete
symmetry gives a contribution (from the charged lepton sector) to the PMNS
mixing matrix which is bimaximal. This gives a strong correlation between the
down quark and charged lepton masses, and the lepton mixing angles. We obtain
that the small entries V_{ub}, V_{cb}, V_{td}, and V_{ts} in the CKM matrix are
related to the small value of the ratio "dm^2_{sol}/dm^2_{atm}": they come from
both the S_2*P structure of our model and the small ratio of the other quark
masses with respect to m_t.


title: Phenomenology of next-leading BFKL

abstract:
  We propose a phenomenological study of the Balitsky-Fadin-Kuraev-Lipatov
(BFKL) approach applied to the data on the proton structure function $F_2$
measured at HERA in the small-$x_{Bj}$ region ($x_{Bj}<0.01$) and $Q^2$ in the
range 5 to 120 GeV$^2$. With a simplified ``effective kernel'' approximation,
we present a comparison between leading-logs (LO) and next-to-leading logs
(NLO) BFKL approaches in the saddle-point approximation, using known resummed
NLO-BFKL kernels. The LO result gives a very good description of the data with
a three parameters fit of $F_2$ but an unphysical value of the strong coupling
constant, whereas the NLO two parameters fit leads to a qualitatively
satisfactory account of the running coupling constant effect but
quantitatively, for $Q^2 < 10$ GeV$^2$, it fails to reproduce properly the
data.


title: Exploiting non-adiabatic density shifts in neutrino interactions

abstract:
  In this paper, we give an exact analytical solution to the case of neutrinos
propagating through multiple non-adiabatic density profiles. The resulting
oscillation probability needs to be modelled in 4-dimensional parameter space
$\{n,L_0,d,\Delta L\}$, where $n$ is the number of iterations, $L_0$ is the
distance from source to first density shift, $d$ is the length of the material
slabs, while $\Delta L$ is the space between them. We show that a set of
resonance parameters can be found to obtain a complete flavor conversion of any
neutrino species. This can be done for both neutrinos and antineutrinos.


title: Divergences and Symmetries in Higgs-Gauge Unification Theories

abstract:
  In theories with extra dimensions the Standard Model Higgs field can be
identified with the internal components of higher-dimensional gauge fields
(Higgs-gauge unification). The higher-dimensional gauge symmetry prevents the
Higgs mass from quadratic divergences, but at the fixed points of the orbifold
this symmetry is broken and divergences can arise if U(1) subgroups are
conserved. We show that another symmetry, remnant of the internal rotation
group after orbifold projection, can avoid the generation of such divergences.


title:
Production of four charged leptons in elecroweak gamma gamma
  interactions

abstract:
  At present paper we performed a detailed numerical analysis of four charged
leptons photoproduction in frame of standard theory of electroweak interaction.
Total and differential cross sections are obtained by using of the Monte-Carlo
method of numerical integration. Different energies of initial photons (60-2000
GeV in c.m.s.), definite and averaged spin states of interacting particles and
fixed kinematical cuts are considered.


title: Excited $[{\bf 70, \ell^+}]$ baryons in large $N_c$ QCD

abstract:
  The masses of the positive parity $[{\bf 70},0^+]$ and $[{\bf 70},2^+]$
non-strange baryons are calculated in large $N_c$ QCD by considering the most
dominant operators in an $1/N_c$ expansion. The approach is based on the
introduction of an excited core, obtained after the last particle (an excited
quark) has been removed. Configuration mixing is neglected, for simplicity.
Although being a sub-leading $1/N_c$ order, we find that the spin-spin
interaction plays a dominant role in describing the data. The role of $N_c^ 0$
operators is also pointed out. We show how the contribution of the linear term
in $N_c$, of the spin-spin and spin-orbit terms vary with the excitation
energy.


title: B mesons and form factors

abstract:
  In order to extract some information on the CKM matrix element |Vcb|, we have
to determine form factors in B decays. For this, we show that it is relevant to
consider the non-forward amplitude between the heavy-light B and D mesons
within the Heavy Quark Effective Theory. This method provides us bounds on the
shape of the elastic Isgur-Wise function. These bounds should be taken into
account in the parametrizations of the Isgur-Wise function used to extract
|Vcb|. Besides, we have also obtain new information on subleading functions at
the order O(1/mQ) where mQ is the heavy quark mass.


title: The Fourth SM Family Neutrino at Future Linear Colliders

abstract:
  It is known that Flavor Democracy favors the existence of the fourth standard
model (SM) family. In order to give nonzero masses for the first three family
fermions Flavor Democracy has to be slightly broken. A parametrization for
democracy breaking, which gives the correct values for fundamental fermion
masses and, at the same time, predicts quark and lepton CKM matrices in a good
agreement with the experimental data, is proposed. The pair productions of the
fourth SM family Dirac $(\nu_{4})$ and Majorana $(N_{1})$ neutrinos at future
linear colliders with $\sqrt{s}=500$ GeV, 1 TeV and 3 TeV are considered. The
cross section for the process $e^{+}e^{-}\to\nu_{4}\bar {\nu_{4}}(N_{1}N_{1})$
and the branching ratios for possible decay modes of the both neutrinos are
determined. The decays of the fourth family neutrinos into muon channels
$(\nu_{4}(N_{1})\to\mu^{\pm}W^{\mp})$ provide cleanest signature at
$e^{+}e^{-}$ colliders. Meanwhile, in our parametrization this channel is
dominant. $W$ bosons produced in decays of the fourth family neutrinos will be
seen in detector as either di-jets or isolated leptons. As an example we
consider the production of 200 GeV mass fourth family neutrinos at
$\sqrt{s}=500$ GeV linear colliders by taking into account di-muon plus
four-jet events as signatures.


title: CP Violation in Charged Higgs Production

abstract:
  I present a study estimating the amount of CP violation present in the
production of charged Higgs bosons due to the presence of complex trilinear
scalar couplings. I compare the results of my study with previous results for
the decay. I briefly comment on the possibility of observing this CP asymmetry
at the LHC.


title: Determination of |V_us| from hadronic tau decays

abstract:
  The recent update of the strange spectral function and the moments of the
invariant mass distribution by the OPAL collaboration from hadronic tau decay
data are employed to determine |V_us| as well as m_s. Our result,
|V_us|=0.2208\pm0.0034, is competitive to the standard extraction of |V_us|
from K_e3 decays and to the new proposals to determine it. Furthermore, the
error associated to our determination of |V_us| can be reduced in the future
since it is dominated by the experimental uncertainty that will be eventually
much improved by the B-factories hadronic tau data. Another improvement that
can be performed is the simultaneous fit of both |V_us| and m_s to a set of
moments of the hadronic tau decays invariant mass distribution, which will
provide even a more accurate determination of both parameters.


title:
Microscopic Description of Deeply Virtual Compton Scattering off Spin-0
  Nuclei

abstract:
  We evaluate within a microscopic calculation the contributions of both
coherent and incoherent deeply virtual Compton scattering from a spin-0
nucleus. The coherent contribution is obtained when the target nucleus recoils
as a whole, whereas for incoherent scattering break-up configurations for the
final nucleus into a an outgoing nucleon and an $A-1$ system are considered.
The two processes encode different characteristics of generalized parton
distributions.


title: Dark Energy and Right-Handed Neutrinos

abstract:
  We explore the possibility that a CP violating phase of the neutrino mass
matrix is promoted to a pseudo-Goldstone-boson field and is identified as the
quintessence field for Dark Energy. By requiring that the quintessence
potential be calculable from a Lagrangian, and that the extreme flatness of the
potential be stable under radiative corrections, we are led to an essentially
unique model. Lepton number is violated only by Majorana masses of light,
right-handed neutrinos, comparable to the Dirac masses that mix right- with
left-handed neutrinos. We outline the rich and constrained neutrino
phenomenology that results from this proposal.


title:
What we (don't) know about black hole formation in high-energy
  collisions

abstract:
  Higher-dimensional scenarios allow for the formation of mini-black holes from
TeV-scale particle collisions. The purpose of this paper is to review and
compare different methods for the estimate of the total gravitational energy
emitted in this process. To date, black hole formation has mainly been studied
using an apparent horizon search technique. This approach yields only an upper
bound on the gravitational energy emitted during black hole formation.
Alternative calculations based on instantaneous collisions of point particles
and black hole perturbation theory suggest that the emitted gravitational
energy may be smaller. New and more refined methods may be necessary to
accurately describe black hole formation in high-energy particle collisions.


title: D-type supersymmetry breaking and brane-to-brane gravity mediation

abstract:
  We revisit the issue of gravitational contributions to soft masses in
five-dimensional sequestered models. We point out that, unlike for the case of
F-type supersymmetry breaking, for D-type breaking these effects generically
give positive soft masses squared for the sfermions. This drastically improves
model building. We discuss the phenomenological implications of our result.


title: Parity-violating asymmetry of $W$ bosons produced in $p$-$p$ collisions

abstract:
  The parity-violating asymmetry is an ideal tool to study the quark helicity
distribution in the proton. We study the parity-violating asymmetry of
$W^{\pm}$ bosons produced by longitudinally polarized $p$-$p$ collision in
RHIC, based on predictions of quark distributions of the proton in the SU(6)
quark-spectator-diquark model and a perturbative QCD based counting rule
analysis. We find that the two models give nearly equal asymmetry for $W^+$ but
that for $W^-$ quite different. Therefore future experiments on such quantity
can help to clarify different predictions of the value $\Delta d(x)/d(x)$ at $x
\to 1$ in the proton.


title:
An "all-poles" approximation to collinear resummations in the Regge
  limit of perturbative QCD

abstract:
  The procedure to improve the convergence in transverse momentum space of the
NLL BFKL kernel using a w-shift is revisited. An accurate approximation to this
shift only depending on transverse momenta is presented. This approximation is
based on a Bessel function of the first kind with argument depending on the
strong coupling and a double logarithm of the ratio of transverse scales. A
comparison between different renormalization schemes is also included.


abstract:
  Heavy-to-light meson form factors at large recoil can be described using the
same techniques as for hard exclusive processes involving only light hadrons.
Two competing mechanisms appear in the large-recoil regime, describing
so-called ``soft-overlap'' and ``hard-scattering'' components of the form
factors. It is shown how existing experimental data from B and D decays
constrain the relative size of these components, and how lattice data can be
used to study properties such as the energy scaling laws obeyed by the
individual components. Symmetry relations between different form factors (F_+,
F_0 and F_T), and between different heavy initial-state mesons (B and D), are
derived in the combined heavy-quark and large-recoil limits, and are shown to
generalize corresponding relations valid at small recoil. Form factor
parameterizations that are consistent with the large-recoil limit are
discussed.


title: Probing Lorentz violation with Doppler-shift experiments

abstract:
  We analyze Doppler-effect experiments in terms of a general framework for
violations of Lorentz symmetry: the Standard-Model Extension. These experiments
are found to be sensitive to heretofore unprobed combinations of
Lorentz-violation coefficients associated with protons and electrons. New
bounds at the level of $10^{-11}$ and $10^{-8}$ for proton coefficients and
$10^{-2}$ for electron coefficients emerge from a recent experiment.


title: Matching Parton Showers to NLO Computation

abstract:
  In this review a new method is presented for attaching parton shower
algorithms to NLO partonic jet cross sections in electron-positron
annihilation. Our method is based on the Catani-Seymour dipole subtraction
method and also uses an adaptation of the matching scheme of Catani, Krauss,
Kuhn, and Webber.


title:
An Analytical Description of Spin Effects in Hadron-Hadron Scattering
  via PMD-SQS Optimum Principle

abstract:
  In this paper an analytical description of spin-effects in hadron-hadron
scattering is presented by using PMD-SQS-optimum principle in which the
differential cross sections in the forward and backward c.m. angles are
considered fixed from the experimental data. The experimental tests of the
optimal predictions, obtained by using the available phase shifts, are
discussed.