title: Dark Energy and Dark Matter in Galaxy Halos

abstract:
  We consider the possibility that the dark matter is coupled through its mass
to a scalar field associated with the dark energy of the Universe. In order for
such a field to play a role at the present cosmological distances, it must be
effectively massless at galactic length scales. We discuss the effects of the
field on the distribution of dark matter in galaxy halos. We show that the
profile of the distribution outside the galaxy core remains largely unaffected
and the approximately flat rotation curves persist. The dispersion of the dark
matter velocity is enhanced by a potentially large factor relative to the case
of zero coupling between dark energy and dark matter. The counting rates in
terrestrial dark matter detectors are similarly enhanced. Existing bounds on
the properties of dark matter candidates can be extended to the coupled case,
by taking into account the enhancement factor.


title: Signals for Low Scale Gravity in the Process $\gamma \gamma \to ZZ$

abstract:
  We investigate the sensitivity of future photon-photon colliders to low scale
gravity scenarios via the process $\gamma\gamma \to ZZ$ where the Kaluza-Klein
boson exchange contributes only when the initial state photons have opposite
helicity. We contrast this with the situation for the process $\gamma \gamma
\to \gamma \gamma$ where the $t$ and $u$ channel also contribute. We include
the one-loop Standard Model background whose interference with the graviton
exchange determines the experimental reach in measuring any deviation from the
Standard Model expectations and explore how polarization can be exploited to
enhance the signal over background. We find that a 1 TeV linear collider has an
experimental reach to mass scale of about 4 TeV in this channel.


title: The Effect of Penguins in the B_d to J/psi K^0 CP asymmetry

abstract:
  Performing a fit to the available experimental data, we quantify the effect
of long-distance contributions from penguin contractions in B^0 to J/psi K^0
decays. We estimate the deviation of the measured S_CP term of the
time-dependent CP asymmetry from sin(2 beta) induced by these contributions and
by the penguin operators. We find Delta S = 0.000 +- 0.012 ([-0.025,0.024] @
95% probability).


title: Conditions for existance of neutral strange quark matter

abstract:
  Breached pairing solutions to the gap equation are obtained analytically in
for two and three quarks and for low and high temperatures. We compare the
energy of these states to that of other homogeneous states under the condition
of electric neutrality. We found the two-flavor BP and the three flavor mixed
BCS-BP phases, which are stable over a wide range of parameters. Both phases
contain four BP modes in the quasiparticle spectrum.


title: Five-dimensional Trinification Improved

abstract:
  We present improved models of trinification in five dimensions. Unified
symmetry is broken by a combination of orbifold projections and a boundary
Higgs sector. The latter can be decoupled from the theory, realizing a
Higgsless limit in which the scale of exotic massive gauge fields is set by the
compactification radius. Electroweak Higgs doublets are identified with the
fifth components of gauge fields and Yukawa interactions arise via Wilson
loops. The result is a simple low-energy effective theory that is consistent
with the constraints from proton decay and gauge unification.


title:
Full one-loop supersymmetric electroweak corrections to $t\bar{t}h^{0}$
  associated production in $e^+e^-$ annihilation

abstract:
  We present a precise calculation of the lightest neutral Higgs boson
production associated with top quark pair at a linear collider. The full
one-loop electroweak ${\cal O}(\alpha_{ew})$ contributions to the process
$e^+e^- \to t\bar t h^0$ within the minimal supersymmetric standard model
(MSSM) are included. We analyze the dependence of the electroweak corrections
on the MSSM parameters such as $M_{A^0}$, $\tan\beta$, $M_2$, $A_{f}$,
$M_{SUSY}$ and $\mu$. The results show that the full one-loop electroweak
radiative corrections turn out to be about -20% quantitatively and thus are
important for future $e^+e^-$ linear colliders.


title: Generalized mirror matter models

abstract:
  Non-minimal gauge models with exact unbroken improper space-time symmetries
are constructed and their cosmological and astrophysical implications explored.


title: Factorization and polarization in two charmed-meson B decays

abstract:
  We provide a comprehensive test of factorization in the heavy-heavy $B$
decays motivated by the recent experimental data from BELLE and BABAR
collaborations. The penguin effects are not negligible in the B decays with two
pseudoscalar mesons. The direct CP asymmetries are found to be a few percent.
We give estimates on the weak annihilation contributions by analogy to the
observed annihilation-dominated processes. The $N_c$ insensitivity of branching
ratios indicates that the soft final state interactions are not dominant. We
also study the polarizations in $B\to D^*D_{(s)}^*$ decays. The power law shows
that the transverse perpendicular polarization fraction is small. The effects
of the heavy quark symmetry breaking caused by the perturbative QCD and power
corrections on the transverse polarization are also investigated.


title:
Distinguishing a SM-like MSSM Higgs boson from SM Higgs boson at muon
  collider

abstract:
  We explore the possibility of distinguishing the SM-like MSSM Higgs boson
from the SM Higgs boson via Higgs boson pair production at future muon
collider. We study the behavior of the production cross section in SM and MSSM
with Higgs boson mass for various choices of MSSM parameters tan \beta and
m\sub A. We observe that at fixed CM energy, in the SM, the total cross section
increases with the increase in Higgs boson mass whereas this trend is reversed
for the MSSM case. The changes that occur for the MSSM case in comparison to
the SM predictions are quantified in terms of the relative percentage deviation
in cross section. The observed large deviations in cross section for different
choices of Higgs mass suggest that the measurements of the cross section could
possibly distinguish the SM-like MSSM Higgs boson from the SM Higgs boson.


title: Constituent quark model study of light- and strange-baryon spectra

abstract:
  We investigate the structure of the SU(3) octet and decuplet baryons
employing a constituent quark model designed for the study of the baryon-baryon
interaction and successfully applied to the meson spectra. The model considers
through the interacting potential perturbative, one-gluon exchange, and
non-perturbative, boson exchanges and confinement, aspects of the underlying
theory, QCD. We solve the three-quark problem by means of the Faddeev method in
momentum space. We analyze the effect of the different terms in the interaction
and make contact with the use of relativistic kinematics. We find an
explanation to the strong contribution of the pseudoscalar forces in the
semirelativistic approach for the octet baryons. A phenomenological recipe for
the regularization parameter of the one-gluon exchange is found.


title: Supersymmetry for Fermion Masses

abstract:
  It is proposed that supersymmetry (SUSY) maybe used to understand fermion
mass hierarchies. A family symmetry Z_{3L} is introduced, which is the cyclic
symmetry among the three generation SU(2) doublets. SUSY breaks at a high
energy scale ~ 10^{11} GeV. The electroweak energy scale ~ 100 GeV is
unnaturally small. No additional global symmetry, like the R-parity, is
imposed. The Yukawa couplings and R-parity violating couplings all take their
natural values which are about (10^0-10^{-2}). Under the family symmetry, only
the third generation charged fermions get their masses. This family symmetry is
broken in the soft SUSY breaking terms which result in a hierarchical pattern
of the fermion masses. It turns out that for the charged leptons, the tau mass
is from the Higgs vacuum expectation value (VEV) and the sneutrino VEVs, the
muon mass is due to the sneutrino VEVs, and the electron gains its mass due to
both Z_{3L} and SUSY breaking. The large neutrino mixing are produced with
neutralinos playing the partial role of right-handed neutrinos. |V_{e3}| which
is for nu_e-nu_{tau} mixing is expected to be about 0.1. For the quarks, the
third generation masses are from the Higgs VEVs, the second generation masses
are from quantum corrections, and the down quark mass due to the sneutrino
VEVs. It explains m_c/m_s, m_s/m_e, m_d > m_u and so on. Other aspects of the
model are discussed.


title: Perturbative approach to U_A(1) breaking

abstract:
  The six-quark instanton induced 't Hooft interaction is considered in
combination with the Nambu-Jona-Lasinio (NJL) type U_L(3)X U_R(3) chiral
symmetric Lagrangian. We discuss the bosonization of this multi-quark
interaction, taking the U_A(1) breaking as a perturbation. We discuss its
relation with the usual approach.


title: Flavor Symmetry L_mu - L_tau and quasi-degenerate Neutrinos

abstract:
  Current data implies three simple forms of the neutrino mass matrix, each
corresponding to the conservation of a non-standard lepton charge. While models
based on L_e and L_e - L_mu - L_tau are well-known, little attention has been
paid to L_mu - L_tau. A low energy mass matrix conserving L_mu - L_tau implies
quasi-degenerate light neutrinos. Moreover, it is mu-tau symmetric and
therefore (in contrast to L_e and L_e - L_mu - L_tau) automatically predicts
maximal atmospheric neutrino mixing and zero U_{e3}. A see-saw model based on
L_mu - L_tau is investigated and testable predictions for the neutrino mixing
observables are given. Renormalization group running below and in between the
see-saw scales is taken into account in our analysis, both numerically and
analytically.


title:
Investigation of g_f0-omega-gamma coupling constant in three point QCD
  sum rules and light cone sum rules

abstract:
  The coupling constant of f0-->omega-gamma decay is calculated using 3-point
sum rule and light cone QCD sum rules. We investigate the results within the
two-models which depend on mixing angle.


title: Distinguishing Between Hierarchical and Lop-sided SO(10) Models

abstract:
  A comparative study of two predictive SO(10) models, namely the BPW model
(proposed by Babu, Pati and Wilczek) and the AB model (proposed by Albright and
Barr) is done based on their predictions regarding CP and flavor violations.
The values of \Delta m_K, \epsilon_K, \Delta m_{B_d} and S(B_d\to J/\psi K_S)
are found, in both models, to be close to SM predictions, in good agreement
with data. Both models predict that S(B_d\to \phi K_S) should lie in the range
+0.65-0.74, close to the SM prediction and that the EDM of the neutron \approx
(few\times 10^{-26})e-cm. It is found that $Br(\mu\to e\gamma)$ in the AB model
is generically much larger than that in the BPW model, being consistent with
the experimental limit only with a rather heavy SUSY spectrum. The BPW model,
on the other hand, is consistent with a much lighter SUSY spectrum. In the AB
model d_e lies in the range 10^{-27}-10^{-28}e-cm. The BPW model gives d_e to
be typically 100 times lower than that in the AB case. Thus the two models can
be distinguished based on their predictions regarding CP and flavor violating
processes, and can be tested in future experiments.


title: Gluonic phase in neutral two-flavor dense QCD

abstract:
  In the Ginzburg-Landau approach, we describe a new phase in neutral
two-flavor quark matter in which gluonic degrees of freedom play a crucial
role. We call it a gluonic phase. In this phase gluonic dynamics cure a
chromomagnetic instability in the 2SC solution and lead to spontaneous
breakdown of the color gauge symmetry, the electromagnetic U(1), and the
rotational SO(3). In other words, the gluonic phase describes an anisotropic
medium in which the color and electric superconductivities coexist. Because
most of the initial symmetries in this system are spontaneously broken, its
dynamics is very rich.


title:
Topics in quantum field theory: Renormalization groups in Hamiltonian
  framework and baryon structure in a non-local QCD model

abstract:
  In this thesis we investigate aspects of two problems. In the first part of
this thesis, we concentrate on renormalization group methods in Hamiltonian
framework. We show that the well-known coupled-cluster many-body theory
techniques can be incorporated in the Wilsonian renormalization group to
provide a very powerful framework for construction of effective Hamiltonian
field theories. Eventhough the formulation is intrinsically non-perturbative,
we have shown that a loop-expansion can be implemented. As illustrative
examples, we apply our formulation on the $\Phi^{4}$ theory and an extended Lee
model. The many-body problem in an extended Lee model is also studied. We show
that a combination of the coupled-cluster theory and the Feshbach projection
techniques leads to a renormalized generalized Brueckner theory. The second
part of the thesis is rather phenomenologically orientated. In this part, we
will employ an effective field-theoretical model as can be constructed by means
of the techniques of the first part of the thesis, a quark-confining non-local
NJL model and study the baryon and diquarks in this model. After truncation of
the two-body channels to the scalar and axial-vector diquarks, a relativistic
Faddeev equation for nucleon bound states is solved in the covariant
diquark-quark picture. We study the possible implications of quark confinement
for the description of the diquarks and the nucleon. We also examine
alternative field theoretical approaches for describing baryons.


title: Diffractive Higgs production

abstract:
  We review the advantages of observing exclusive diffractive Higgs production
at the LHC. We note the importance of the Sudakov form factor in predicting the
event rate. We discuss briefly other processes which may be used as `standard
candles'.


title: A Neutral Two Flavor Loff Color Superconductor

abstract:
  In this paper we construct analytically a LOFF color superconducting state
that is both color and charge neutral using the weak coupling approximation. We
demonstrate that this state is free from chromomagnetic instabilities. Its
relevance to the realistic quark matter at moderately high baryon density is
discussed.


title: A Unified Picture with Neutrino As a Central Feature

abstract:
  In the first part of this talk it is discussed why observed neutrino
oscillations (which suggest the existence of right-handed neutrinos with
certain Dirac and Majorana masses) seem to select out the route to higher
unification based on the symmetry SU(4)-color. This in turn selects out the
effective symmetry in 4D near the GUT/string scale to be either SO(10) or
minimally G(224)= SU(2)_L\times SU(2)_R \times SU(4)^c. The same conclusion is
reached by the likely need for leptogenesis as the means for baryogenesis and
also by the success of certain fermion mass-relations including
m_b(M_{GUT})\approx m_\tau, together with m(\nu^\tau)_{Dirac}\approx
m_{top}(M_{GUT}). In the second part, an attempt is made to provide a unified
picture of a set of diverse phenomena based on an effective G(224) symmetry or
SO(10), possessing supersymmetry. The phenomena in question include: (a)
fermion masses and mixings, (b) neutrino oscillations, (c) CP non-conservation,
(d) flavor violations in quark and lepton sectors, as well as (e) baryogenesis
via leptogenesis. Including SM and SUSY contributions, the latter being
sub-dominant, the framework correctly accounts for \Delta m_K, \Delta m_{B_d},
  S(B_d -> J/\psi K_s) and \epsilon_K, and predicts S(B_d-> \phi K_s) to be in
the range +(0.65-0.73), close to the SM-prediction. It also quite plausibly
accounts for the observed baryon excess Y_B\approx 10^{-10}. Furthermore the
model predicts enhanced rates for mu -> e gamma, tau-> mu gamma and mu N-> e N
and also measurable electric dipole moment for the neutron. Expectations
arising within the same framework for proton decay are summarized at the end.
It is stressed that the potential for discovering proton decay in a
megaton-size detector would be high.


title: Deducing Rest Masses of Quarks With a Three Step Quantization

abstract:
  Using a three step quantization and phenomenological formulae, we can deduce
the rest masses and intrinsic quantum numbers (I, S, C, B and Q) of quarks from
only one unflavored elementary quark family $\epsilon$ with S = C = B = 0 in
the vacuum. Then using sum laws, we can deduce the rest masses and intrinsic
quantum numbers of baryons and meson from the deduced quarks. The deduced
quantum numbers match experimental results exactly. The deduced rest masses are
consistent with experimental results. This paper predicts some new quarks
[d_{s}(773), d_{s}(1933), u_{c}(6073), d_{b}(9333)], baryons
[$\Lambda_{c}$(6699), $\Lambda_{b}$(9959)] and mesons [D(6231), B(9502)]. PACS:
12.60.-i; 12.39.-x; 14.65.-q; 14.20.-c Key word: beyond the standard model


title: Determination of electroweak parameters at HERA with the H1 experiment

abstract:
  Using deep inelastic $e^{\pm}p$ charged and neutral current scattering cross
sections previously published, a combined electroweak and QCD analysis is
performed to determine electroweak parameters accounting for their correlation
with parton distributions. The data used have been collected by the H1
experiment in 1994-2000 and correspond to an integrated luminosity of 117.2
pb$^{-1}$. The $W$ boson mass is determined via the propagator and in the
on-mass-shell scheme. A first measurement at HERA is made of the light quark
weak couplings to the $Z^0$ boson.


title:
Leading twist nuclear shadowing and suppression of hard coherent
  diffraction in proton-nucleus scattering

abstract:
  We use the Glauber-Gribov multiple scattering formalism and the theory of
leading twist nuclear shadowing to develop a method for the calculation of
leading twist hard coherent diffraction in hadron-nucleus processes. We
demonstrate that soft multiple rescatterings lead to the factorization breaking
of hard diffraction in proton-nucleus scattering, which is larger than in
hadron-nucleon scattering. At the LHC and RHIC kinematics, we compare the hard
diffractive to e.m.~mechanisms of hard coherent production of two jets in
proton-nucleus scattering. We study the x_{\Pomeron}, \beta and A-dependence of
the ratio of the dijet production cross sections due to the two effects, R. We
demonstrate that in proton-heavy nucleus hard coherent diffraction at the LHC,
R is small, which offers a clean method to study hard photon-proton scattering
at the energies exceeding the HERA energies by the factor of ten. On the other
hand, the use of lighter nuclei, such as Ca-40, will allow to study the
screened nuclear diffractive parton distribution. Moreover, a comparison of the
dijet diffractive production to the heavy-quark-jet diffractive production will
estimate the screened nuclear diffractive gluon PDF, which will be measured in
nucleus-nucleus ultraperipheral collisions at the LHC.


title:
Rare Weak Decays and Direct Lepton Number Violating Signals in a Minimal
  R-Parity Violating Model of Neutrino Mass

abstract:
  Within the framework of R-parity violating minimal supergravity model, at
least three relatively large lepton-number violating $\l'$ type trilinear
couplings at the GUT scale, not directly related to neutrino physics, can
naturally generate via renormalization group (RG) evolution and/or CKM rotation
the highly suppressed bilinear and trilinear parameters at the weak scale
required to explain the neutrino oscillation data. The structure of the RG
equations and the CKM matrix restrict the choices of the three input couplings
to only eight possible combinations, each with its own distinctive experimental
signature. The relatively large input couplings may lead to spectacular low
energy signatures like rare weak decays of the $\tau$ lepton and K mesons,
direct lepton number violating decays of several sparticles, and unconventional
decay modes (and reduced lifetime) of the lightest neutralino, assumed to be
the lightest supersymmetric particle (LSP), all with sizable branching ratios.
Several low background signals at the Tevatron and LHC have been suggested and
their sizes are estimated to be at the observable level. From the particle
content of the signal and the relative rate of different final states the input
couplings at the GUT scale, i.e., the origin of neutrino masses and mixing
angles, can be identified.


title: Broken mu-tau Symmetry and Leptonic CP Violation

abstract:
  We propose that leptonic CP violation arises from a breaking of the mu-tau
exchange symmetry in the neutrino mass matrix which in turn is indicated by the
near maximal atmospheric neutrino mixing and the near zero \theta_{13}. We find
that for the case of a normal hierarchy, present data already restricts the way
CP violation may appear in the neutrino mass matrix and there is an interesting
correlation between the mixing angle \theta_{13}, the solar mixing angle
\theta_{12} and the Dirac CP phase. In the inverted hierarchy only \theta_{13}
and the Dirac phase are linked. We also discuss the impact of this kind of CP
violation on the deviation of the atmospheric mixing from its maximal value.
Moreover, if corrections to mu-tau symmetry arise from the charged lepton
sector, where mu-tau symmetry is known to be broken anyway, we find interesting
connections between the CP-even and -odd terms as well. Our predictions are
testable in the proposed long baseline neutrino experiments.


title: Kaluza-Klein Mesons in Universal Extra Dimensions

abstract:
  In models with universal extra dimensions, the isosinglet Kaluza-Klein (KK)
quarks, q^1, have very narrow widths, of O(5-10) MeV, and will thus hadronize.
Studies of KK-quarkonia, \bar{q}^1 q^1, show very sharp resonances and dramatic
signatures at the Linear Collider. In this Brief Report, we consider the
possibility of detecting KK-mesons, \bar{q}^1 q, and show that detection at a
Linear Collider is unlikely.


title: Bottomonium Production at RHIC and LHC

abstract:
  Properties of bottomonia (Upsilon, chi_b and Upsilon') in the Quark-Gluon
Plasma (QGP) are investigated by assessing inelastic reaction rates and their
interplay with open-bottom states (b-quarks or B-mesons) and color-screening.
The latter leads to vanishing quarkonium binding energies at sufficiently high
temperatures (close to the dissolution point), which, in particular, renders
standard gluo-dissociation, g+Upsilon -> b + b-bar, inefficient due to a
substantial reduction in final-state phase space. This problem is overcome by
invoking a "quasifree" destruction mechanism, g,q,q-bar + Upsilon -> g,q,q-bar
+ b + b-bar, as previously introduced for charmonia. The pertinent reaction
rates are implemented into a kinetic theory framework to evaluate the time
evolution of bottomonia in heavy-ion reactions at RHIC and LHC within an
expanding fireball model. While bottom quarks are assumed to be exclusively
produced in primordial nucleon-nucleon collisions, their thermal relaxation
times in the QGP, which importantly figure into Upsilon-formation rates, are
estimated according to a recent Fokker-Planck treatment. Predictions for the
centrality dependence of Upsilon production are given for upcoming experiments
at RHIC and LHC. At both energies, Upsilon suppression turns out to be the
prevalent effect.


title: Suppressing Super-Horizon Curvature Perturbations?

abstract:
  We consider the possibility of suppressing superhorizon curvature
perturbations after the end of the ordinary slow-roll inflationary stage. This
is the opposite of the curvaton limit. We assume that large curvature
perturbations are created by the inflaton and investigate if they can be
diluted or suppressed by a second very homogeneous field which starts to
dominate the energy density of the universe shortly after the end of inflation.
We show explicit that the gravitational sourcing of inhomogeneities from the
more inhomogeneous fluid to the more homogeneous fluid makes the suppression
difficult if not impossible to achieve.


title:
Pion and Quark Annihilation Mechanisms of Dilepton Production in
  Relativistic Heavy-Ion Collisions

abstract:
  We revise the pion-pion and quark-quark annihilation mechanisms of dilepton
production during relativistic heavy-ion collisions. We focus on the
modifications caused by the specific features of intramedium pion states rather
than by medium modification of the rho-meson spectral density. The main
ingredient emerging in our approach is a form-factor of the multi-pion
(multi-quark) system. Replacing the usual delta-function the form-factor plays
the role of distribution which, in some sense, "connects" the 4-momenta of the
annihilating and outgoing particles. The difference between the c.m.s.
velocities attributed to annihilating and outgoing particles is a particular
consequence of this replacement and results in the appearance of a new factor
in the formula for the dilepton production rate. We obtained that the
form-factor of the multi-pion (multi-quark) system causes broadening of the
rate which is most pronounced for small invariant masses, in particular, we
obtain a growth of the rate for the invariant masses below two masses of the
annihilating particles.


title: W production at large transverse momentum at the Large Hadron Collider

abstract:
  We study the production of W bosons at large transverse momentum in pp
collisions at the Large Hadron Collider (LHC). We calculate the complete
next-to-leading order (NLO) corrections to the differential cross section. We
find that the NLO corrections provide a large increase to the cross section
but, surprisingly, do not reduce the scale dependence relative to leading order
(LO). We also calculate next-to-next-to-leading-order (NNLO) soft-gluon
corrections and find that, although they are small, they significantly reduce
the scale dependence thus providing a more stable theoretical prediction.


title: Heavy Quark Diffusion from the Lattice

abstract:
  We study the diffusion of heavy quarks in the Quark Gluon Plasma using the
Langevin equations of motion and estimate the contribution of the transport
peak to the Euclidean current-current correlator. We show that the Euclidean
correlator is remarkably insensitive to the heavy quark diffusion coefficient
and give a simple physical interpretation of this result using the free
streaming Boltzmann equation. However if the diffusion coefficient is smaller
than $\sim 1/(\pi T)$, as favored by RHIC phenomenology, the transport
contribution should be visible in the Euclidean correlator. We outline a
procedure to isolate this contribution.


title:
Neutrino Mixing Predictions of a Minimal SO(10) Model with Suppressed
  Proton Decay

abstract:
  During the past year, a minimal renormalizable supersymmetric SO(10) model
has been proposed with the following properties: it predicts a naturally stable
dark matter and neutrino mixing angles theta_atm and theta_13 while at the same
time accommodating CKM CP violation among quarks with no SUSY CP problem.
Suppression of proton decay for all allowed values of tan beta strongly
restricts the flavor structure of the model making it predictive for other
processes as well. We discuss the following predictions of the model in this
paper, e.g. down-type quark masses, and neutrino oscillation parameters, U_e3,
delta_MNSP, which will be tested by long baseline experiments such as T2K and
subsequent experiments using the neutrino beam from JPARC. We also calculate
lepton flavor violation and the lepton asymmetry of the Universe in this model.


title: Impact of the pion mass on nonpower expansion for QCD observables

abstract:
  A new set of functions, which form a basis of the massive nonpower expansion
for physical observables, is presented in the framework of the analytic
approach to QCD at the four-loop level. The effects due to the $\pi$ meson mass
are taken into account by employing the dispersion relation for the Adler
function. The nonvanishing pion mass substantially modifies the functional
expansion at low energies. Specifically, the spacelike functions are affected
by the mass of the $\pi$ meson in the infrared domain below few GeV, whereas
the timelike functions acquire characteristic plateaulike behavior below the
two-pion threshold. At the same time, all the appealing features of the
massless nonpower expansion persist in the considered case of the nonvanishing
pion mass.


title: The Quartic Higgs Coupling at Hadron Colliders

abstract:
  The quartic Higgs self-coupling is the final measurement in the Higgs
potential needed to fully understand electroweak symmetry breaking. None of the
present or future colliders are known to be able to determine this parameter.
We study the chances of measuring the quartic self-coupling at hadron colliders
in general and at the VLHC in particular. We find the prospects challenging.


title:
Improved theoretical prediction for the 2s hyperfine interval in helium
  ion

abstract:
  We consider the uncertainty of theoretical calculations for a specific
difference of the hyperfine intervals in the 1s and 2s states in a light
hydrogen-like atom. For a number of crucial radiative corrections the result
for hydrogen atom and helium ion appears as an extrapolation of the numerical
data from medium to low Z. An approach to a plausible estimation of the
uncertainty is suggested using the example of the difference $D_{21}=
8E_{hfs}(2s)-E_{hfs}(1s)$.


title: Isospin odd pi K scattering length

abstract:
  We make use of the chiral two-loop representation of the pi K scattering
amplitude [J. Bijnens, P. Dhonte and P. Talavera, JHEP 0405 (2004) 036] to
investigate the isospin odd scattering length at next-to-next-to-leading order
in the SU(3) expansion. This scattering length is protected against
contributions of m_s in the chiral expansion, in the sense that the corrections
to the current algebra result are of order M_pi^2. In view of the planned
lifetime measurement on pi K atoms at CERN it is important to understand the
size of these corrections.


title:
Polarization effects in exclusive semileptonic (Lambda_b -> Lambda l^+
  l^-) decay

abstract:
  The independent helicity amplitudes in the (Lambda_b -> \Lambda l^+ l^-)
decay in the standard model and its minimal extension, i.e., with the new
vector type interactions, are calculated. We calculate various asymmetry
parameters characterizing the angular dependence of the differential decay
width for the cascade decay (Lambda_b -> Lambda(-> a+b) V^* (-> l^+ l^-)) with
polarized and unpolarized heavy baryons. The sensitivity of the asymmetry
parameters to the new Wilson coefficients are analyzed.


title: Electroweak Baryogenesis, Large Yukawas and Dark Matter

abstract:
  It has been recently shown that the electroweak baryogenesis mechanism is
feasible in Standard Model extensions containing extra fermions with large
Yukawa couplings. We show here that the lightest of these fermionic fields can
naturally be a good candidate for cold dark matter. We find regions in the
parameter space where the thermal relic abundance of this particle is
compatible with the dark matter density of the Universe as determined by the
WMAP experiment. We study direct and indirect dark matter detection for this
model and compare with current experimental limits and prospects for upcoming
experiments. We find, contrary to the standard lore, that indirect detection
searches are more promising than direct detection ones, and they already
exclude a portion of the parameter space.


title: Revisiting the annihilation decay $\bar{B}_{s}\to\pi^{+}\pi^{-}$

abstract:
  It is very important to know the strength of annihilation contribution in B
charmless nonleptonic decays. $\bar{B}_{s}\to \pi^{+}\pi^{-}$ process could
serve a good probe of the strength. We have studied the process in QCD
factorization framework. Using a gluon mass scale indicted by the studies of
infrared behavior of gluon propagators to avoid enhancements in the soft end
point regions, we find that the CP averaged branching ratio is about
$1.24\times 10^{-7}$, the direct CP asymmetry $C_{\pi\pi}$ is about -0.05,
while the mixing-induced CP asymmetry quite large with the value
$S_{\pi\pi}$=0.18. The process could be measured at LHC-b experiments in the
near future and would deepen our understanding of dynamics of B charmless
decays.


title: g1(x) and g2(x) in the Meson Cloud Model

abstract:
  We calculate the spin dependent structure functions g1(x) and g2(x) of the
proton and neutron. Our calculation uses the meson cloud model of nucleon
structure and includes the effects of kinematic terms which mix transverse and
longitudinal spin components. We find small corrections to the nucleon
structure functions, however these are significant for the neutron.


title:
The extension to the transverse momentum of the statistical parton
  distributions

abstract:
  By extending the statistical distributions to the transverse degree of
freedhom, we account for a multiplicative factor in the Fermi-Dirac functions
of the light quarks, we were led to introduce in a previous work to comply with
experiment. We can also get light antiquark distributions, similar to those we
proposed earlier


title: Some remarks on tree-level vacuum stability in two Higgs doublet models

abstract:
  It is proved that the minimum of a general two Higgs doublet models'
potential is stable at tree level. A relation between stability and flavour
changing neutral currents at tree level is shown.


title: Confinement and parity doubling in heavy-light mesons

abstract:
  In this paper, we study the chiral symmetry restoration in the hadronic
spectrum in the framework of generalised Nambu-Jona-Lasinio quark models with
instantaneous confining quark kernels. We investigate a heavy-light quarkonium
and derive its bound-state equation in the form of a Schroedingerlike equation
and, after the exact inverse Foldy-Wouthuysen transformation, in the form of a
Diraclike quation. We discuss the Lorentz nature of confinement for such a
system and demonstrate explicitly the effective chiral symmetry restoration for
highly excited states in the mesonic spectrum. We give an estimate for the
scale of this restoration.


title:
Soft Gluon Resummation Effects in Single Slepton Production at Hadron
  Colliders

abstract:
  We investigate QCD effects in the production of a single slepton at hadron
colliders in the Minimal Supersymmetric Standard Model without R-parity. We
calculate the total cross sections and the transverse momentum distributions at
next-to-leading order in QCD. The NLO corrections enhance the total cross
sections and decrease the dependence of the total cross sections on the
factorization and renormalization scales. For the differential cross sections,
we resum all order soft gluon effects to give reliable predictions for the
transverse momentum distributions. We also compare two approaches to the
non-perturbative parametrization and found that the results are slightly
different at the Tevatron and are in good agreement at the LHC. Our results can
be useful to the simulation of the events and to the future collider
experiments.


title: Determination of Neutrino Mass Texture for Maximal CP Violation

abstract:
  We show a general form of neutrino mass matrix (M), whose matrix elements are
denoted by M_{ij} (i.j=e, mu, tau) as flavor neutrino masses, that induces
maximal CP violation as well as maximal atmospheric neutrino mixing. The masses
of M_{mu mu}, M_{tau tau} and M_{mu tau}+sigma M_{ee} (sigma =\pm 1) turn out
to be completely determined by M_{e mu} and M_{e tau} for given mixing angles.
The appearance of CP violation is found to originate from the interference
between the mu-tau symmetric part of M and its breaking part. If |M_{e
mu}|=|M_{e tau}|, giving either M_{e mu}=-sigma e^{i theta} M_{e tau} or M_{e
mu}=-sigma e^{i theta}M*_{e tau} with a phase parameter theta, is further
imposed, we find that |M_{mu mu}|=|M_{tau tau}|is also satisfied. These two
constraints can be regarded as an extended version of the constraints in the
mu-tau symmetric texture given by M_{e mu}=-sigma M_{e tau} and M_{mu
mu}=M_{tau tau}. Majorana CP violation becomes active if arg(M_{mu tau})\neq
arg(M_{e mu})+theta/2 for M_{e mu}=-sigma e^{i theta} M_{e tau} and if
arg(M_{mu tau})\neq theta/2 for M_{e mu}=-sigma e^{i theta} M*_{e tau}.


title: Leptogenesis in Unified Theories with Type II See-Saw

abstract:
  In some classes of flavour models based on unified theories with a type I
see-saw mechanism, the prediction for the mass of the lightest right-handed
neutrino is in conflict with the lower bound from the requirement of successful
thermal leptogenesis. We investigate how lifting the absolute neutrino mass
scale by adding a type II see-saw contribution proportional to the unit matrix
can solve this problem. Generically, lifting the neutrino mass scale increases
the prediction for the mass of the lightest right-handed neutrino while the
decay asymmetry is enhanced and washout effects are reduced, relaxing the lower
bound on the mass of the lightest right-handed neutrino from thermal
leptogenesis. For instance in classes of unified theories where the lightest
right-handed neutrino dominates the type I see-saw contribution, we find that
thermal leptogenesis becomes possible if the neutrino mass scale is larger than
about 0.15 eV, making this scenario testable by neutrinoless double beta decay
experiments in the near future.


title: Subcritical Fission Reactor Based on Linear Collider

abstract:
  The beams of Linear Collider after main collision can be utilized to build an
accelerator--driven sub--critical reactor.


title: Neutrino Factory Based on Linear Collider

abstract:
  The beams of Linear Collider after main collision can be utilized to build
neutrino factory with exceptional parameters. We also discuss briefly possible
applications of some elements of proposed scheme for standard fixed target
experiments, new experiments with \nu_\mu N interactions and in material
sciences.


title:
Electromagnetic structure and weak decay of pseudoscalar mesons in a
  light-front QCD-inspired model

abstract:
  We study the scaling of the $^3S_1-^1S_0$ meson mass splitting and the
pseudoscalar weak decay constants with the mass of the meson, as seen in the
available experimental data. We use an effective light-front QCD-inspired
dynamical model regulated at short-distances to describe the valence component
of the pseudoscalar mesons. The experimentally known values of the mass
splittings, decay constants (from global lattice-QCD averages) and the pion
charge form factor up to 4 [GeV/c]$^2$ are reasonably described by the model


title:
Space-like and time-like pion electromagnetic form factor and Fock state
  components within the Light-Front dynamics

abstract:
  The simultaneous investigation of the pion electromagnetic form factor in the
space- and time-like regions within a light-front model allows one to address
the issue of non-valence components of the pion and photon wave functions. Our
relativistic approach is based on a microscopic vector meson dominance (VMD)
model for the dressed vertex where a photon decays in a quark-antiquark pair,
and on a simple parametrization for the emission or absorption of a pion by a
quark. The results show an excellent agreement in the space like region up to
-10 $(GeV/c)^2$, while in time-like region the model produces reasonable
results up to 10 $(GeV/c)^2$.


title: High Energy Neutrino Interactions

abstract:
  We study ultrahigh energy astrophysical neutrinos and their interactions
within the Standard Model and beyond. We consider propagation of muon
neutrinos, tau neutrinos that originate in $\nu_\mu \to \nu_\tau$ oscillations,
and tau leptons produced in charged-current neutrino interactions. We show that
high energy taus lose their energy through bremsstrahlung, pair production and
photonuclear processes until they reach energy of $\sim 10^8$ GeV, bellow which
they are more likely to decay. Neutrino interactions at energies above
$10^8$GeV could lead to the production of microscopic black holes predicted in
theories of extra dimensions, or they can undergo instanton-induced processes.
We discuss potential signals for these processes in detectors such as IceCube
and ANITA.


title: Ultrahigh Energy Tau Neutrinos

abstract:
  We study ultrahigh energy astrophysical neutrinos and the contribution of tau
neutrinos from neutrino oscillations, relative to the contribution of the other
flavors. We show the effect of tau neutrino regeneration and tau energy loss as
they propagate through the Earth. We consider a variety of neutrino fluxes,
such as cosmogenic neutrinos and neutrinos that originate in Active Galactic
Nuclei. We discuss signals of tau neutrinos in detectors such as IceCube, RICE
and ANITA.


title: $\theta-$ Parameter in 2 Color QCD at Finite Baryon and Isospin Density

abstract:
  We use 2-color QCD as a model to study the effects of simultaneous presence
of the so-called $\theta$ parameter, chemical potentials for baryon number,
$\mu_B$ and for isospin charge, $\mu_I$. We pay special attention to $\theta$,
$\mu_B$, $\mu_I$ dependence of different vacuum condensates, including chiral
and diquark condensates, as well as the gluon condensate, $<G^2>$, and the
topological susceptibility. We find that two phase transitions of the second
order will occur when $\theta$ relaxes from $\theta=2\pi$ to $\theta=0$, if
$\mu$ is of order of the pion mass. We demonstrate that the transition to the
superfluid phase at $\theta = \pi$ occurs at a much lower chemical potential
than at $\theta = 0$. We also show that the strong $\theta$ dependence present
near $\theta = \pi$ in vacuum (Dashen's phenomenon), becomes smoothed out in
the superfluid phase. Finally, we comment on the relevance of this study for
the real world with N_c=3.


title: Summary of the "Diffraction & Vector Mesons" working group at DIS05

abstract:
  We survey the contributions presented in the working group "Diffraction &
Vector Mesons" at the XIII International Workshop on Deep Inelastic Scattering
(http://www.hep.wisc.edu/dis05)


title:
Littlest Higgs model and top-charm production at high-energy linear
  colliders

abstract:
  Due to the presence of extra top quark T in the little Higgs models, the
$CKM$ matrix is not unitary and the flavor changing neutral currents may exist
at the tree level. In the context of the Littlest Higgs(LH) model, we discuss
the top-charm production at the high-energy linear $e^{+}e^{-}$ collider $(LC)$
via the processes $e^{+}e^{-}\to \bar{t}c +t\bar{c}$, $e^{+}e^{-}\to (\bar{t}c
+t\bar{c})\nu_{e}\bar{\nu_{e}}$, and $e^{-}\gamma\to e^{-}\bar{t}c$. We find
that the resonance production cross section for the process $e^{+}e^{-}\to
\bar{t}c+ t\bar{c} $ is significantly larger, which can be detected in future
$LC$ experiments.


title: A Unified Model for inelastic e-N and nu-N cross sections at all Q2

abstract:
  We present results using a new scaling variable, xi_w in modeling electron-
and neutrino-nucleon scattering cross sections with effective leading order
PDFs.Our model uses all inelastic charged lepton F_2 data
(SLAC/BCDMS/NMC/HERA), and photoproduction data on hydrogen and deuterium. We
find that our model describes all inelastic scattering charged lepton data, the
average of JLAB resonance data, and neutrino data at all Q2. This model is
currently used by current neutrino oscillation experiments in the few GeV
region.


title: What if $\theta_{13}$ Is Small?

abstract:
  In the basis where the charged lepton mass matrix is diagonal, the
left-handed neutrino mass matrix is invariant under the permutation of the
second and third generations if, and only if, the reactor angle $\theta_{13}$
is zero and the atmospheric mixing angle $\theta_{23}$ is maximal. In the
presence of the seesaw mechanism, this symmetry leads to an inverted hierarchy,
with $m_3=0$. This inverted mass spectrum is doubly protected if the
right-handed neutrinos also have a 2-3 symmetry.


title: Looking for the Top-squark at the Tevatron with four jets

abstract:
  The scalar partner of the top quark is relatively light in many models of
supersymmetry breaking. We study the production of top squarks (stops) at the
Tevatron collider and their subsequent decay through baryon-number violating
couplings such that the final state contains no leptons. Performing a
detector-level analysis, we demonstrate that, even in the absence of leptons or
missing energy, stop masses upto 210 \gev/c^2 can be accessible at the
Tevatron.


title:
Light-cone sum rules for the heavy-to-light transition in the effective
  theory

abstract:
  Heavy-to-light weak form factor is calculated using the light-cone sum rule
(LCSR)in the framework of soft-collinear effective theory (SCET). There are
spin-symmetric and spin-nonsymmetric contributions. Leading order
spin-symmetric contribution corresponds to the ''soft overlap'' where some of
the partons carry very small momentum. The next-to-leading order spin-symmetric
and spin-nonsymmetric parts are characterized by a collinear gluon exchange
with the spectator quark. We reproduce the full theory LCSR results and give
comments on recent LCSR in SCET.


title: Goldstone boson counting in linear sigma models with chemical potential

abstract:
  We analyze the effects of finite chemical potential on spontaneous breaking
of internal symmetries within the class of relativistic field theories
described by the linear sigma model. Special attention is paid to the emergence
of ``abnormal'' Goldstone bosons with quadratic dispersion relation. We show
that their presence is tightly connected to nonzero density of the Noether
charges, and formulate a general counting rule. The general results are
demonstrated on an SU(3)xU(1) invariant model with an SU(3)-sextet scalar
field, which describes one of the color-superconducting phases of QCD.


title:
Covariant Extremisation of Flavour-Symmetric Jarlskog Invariants and the
  Neutrino Mixing Matrix

abstract:
  We examine the possibility that the form of the lepton mixing matrix can be
determined by extremising the Jarlskog flavour invariants associated, eg. with
the commutator ($C$) of the lepton mass matrices. Introducing a strictly
covariant approach, keeping masses fixed and extremising the determinant (Tr
$C^3/3$) leads to maximal CP violation, while extremising the sum of the $2
\times 2$ principal minors ($-{\rm Tr} C^2/2$), leads to a non-trivial mixing
with zero CP violation. Extremising, by way of example, a general linear
combination of two CP-symmetric invariants together, we show that our
procedures can lead to acceptable mixings and to non-trivial predictions, eg.\
$|U_{e3}| \simeq \sqrt{2}/3 \sqrt{\Delta m_{12}^2/\Delta m_{23}^2}
(1-m_{\mu}/m_{\tau})^2 \simeq 0.07$.


title:
Bottom-quark fragmentation: comparing results from tuned event
  generators and resummed calculations

abstract:
  We study bottom-quark fragmentation in e+e- annihilation, top and Higgs decay
H -> b bbar, using Monte Carlo event generators, as well as calculations, based
on the formalism of perturbative fragmentation functions, which resum soft- and
collinear-radiation effects in the next-to-leading logarithmic approximation.
We consider the PYTHIA and HERWIG generators, and implement matrix-element
corrections to the parton shower simulation of the H -> b bbar process in
HERWIG. We tune the Kartvelishvili, string and cluster models to B-hadron data
from LEP and SLD, and present results in both x_B and moment spaces. The
B-hadron spectra yielded by HERWIG, PYTHIA and resummed calculations show small
discrepancies, which are due to the different approaches and models employed
and to the quality of the fits to the e+e- data.


title: Chiral Fermion Delocalization in Deconstructed Higgsless Theories

abstract:
  {I construct a renormalizable $SU(2)^{89}\times U(1)$ gauge theory with
standard-model-like phenomenology for the gauge bosons masses and the weak
interactions of the light fermions (including the $b$) but in which all vacuum
expectation values are about 2 TeV. This is a deconstructed version of a
Higgsless model with a flat extra dimension. The fermions are delocalized on
the theory space in an unusual way, with LH and RD fermions on alternate nodes.


title: PHOTOS as a pocket parton shower: flexibility tests for the algorithm

abstract:
  In this note we will recall the main tests that document robustness and
flexibility of the PHOTOS design. This aspect may be of broader use and may
find extensions in future applications, also outside the simple case of purely
QED bremsstrahlung in decays. The components of the PHOTOS algorithm will be
presented using operator language. The results of some flexibility tests, not
documented before, will also be presented.


title:
Next-to-Leading Order QCD Corrections to the Direct Top Quark Production
  via Model-independent FCNC Couplings at Hadron Colliders

abstract:
  We calculated the next-to-leading order (NLO) QCD corrections to the cross
sections for direct top quark productions induced by model--independent flavour
changing neutral current couplings at hadron colliders. The NLO results
increase the experimental sensitivity to the anomalous couplings. Our results
show that the NLO QCD corrections enhance the leading order (LO) total cross
sections at the Tevatron Run 2 about 60% for both of $\kappa_{tc}^g$ and
$\kappa_{tu}^g$ couplings, and enhance the LO total cross sections at the LHC
about 40% for $\kappa_{tc}^g$ couplings and 50% for $\kappa_{tu}^g$ couplings,
respectively. Moreover, the NLO QCD corrections vastly reduce the dependence of
the total cross sections on the renormalization or factorization scale, which
leads to increased confidence in predictions based on these results.


title:
Some comments on the divergence of perturbation series in Quantum
  Eletrodynamics

abstract:
  It has been argued by Dyson that the perturbation series in coupling constant
in QED can not be convergent. We find that similiar albeit slightly different
arguments lead to the divergence of the series of $1/N_f$ expansion in QED.


title: Cosmological constant from gauge fields on extra dimensions

abstract:
  We present a new model of dark energy which could explain the observed
accelerated expansion of our Universe. We show that a five-dimensional
Einstein-Yang-Mills theory defined in a flat Friedmann-Robertson-Walker
universe compactified on a circle possesses degenerate vacua in four
dimensions. The present Universe could be trapped in one of these degenerate
vacua. With the natural requirement that the size of the extra dimension could
be of the GUT scale or smaller, the energy density difference between the
degenerate vacua and the true ground state can provide us with just the right
amount of dark energy to account for the observed expansion rate of our
Universe.


title: The Higgs boson as a gauge field in extra dimensions

abstract:
  I review, at a general non-technical level, the main properties of models in
extra dimensions where the Higgs field is identified with some internal
component of a gauge field.


title: Tree-level unitarity constraints in the most general 2HDM

abstract:
  We obtain tree-level unitarity constraints for the most general Two Higgs
Doublet Model (2HDM) with explicit CP-violation. We briefly discuss
correspondence between possible violation of tree level unitarity limitation
and physical content of the theory.


title:
Determining the Stau Trilinear Coupling A_tau in Supersymmetric Higgs
  Decays

abstract:
  The measurement of the trilinear couplings A in the part of the Lagrangian
which breaks supersymmetry softly will be a difficult experimental task. In
this report the heavy Higgs decays H,A -> stau_1 stau_2 to stau pairs are
investigated for measuring the stau trilinear coupling A_tau. Based on detailed
simulations of signal and backgrounds for a specific reference point in future
high luminosity e+e- linear collider experiments, it is concluded that the
parameter $_tau can be determined with a precision at the 10% level in the
region of moderate to large tan(beta).


title:
NMHDECAY 2.0: An updated program for Sparticle masses, Higgs masses,
  couplings and decay widths in the NMSSM

abstract:
  We describe the the improved properties of the NMHDECAY program, that is
designed to compute Higgs and sparticle masses and Higgs decay widths in the
NMSSM. In the version 2.0, Higgs decays into squarks and sleptons are included,
accompagnied by a calculation of the squark, gluino and slepton spectrum and
tests against constraints from LEP and the Tevatron. Further radiative
corrections are included in the Higgs mass calculation. A link to MicrOMEGAs
allows to compute the dark matter relic density, and a rough (lowest order)
calculation of the BR(s -> b gamma) is performed.


title: Quantum and Classical divide: the gravitational case

abstract:
  We study the transition between quantum and classical behavior of particles
in a gravitational quantum well. We analyze how an increase in the particles
mass turns the energy spectrum into a continuous one, from an experimental
point of view. We also discuss the way these effects could be tested by
conducting experiments with atoms and fullerene-type molecules.


title: Probing Flavor Structure in Supersymmetric Theories

abstract:
  We analyze the possibility of probing the supersymmetric flavor structure
through the constraints of the K and B meson systems and those of the electric
dipole moments. We show that combining these constraints would favor SUSY
models with large flavor mixing either in LR(RL) or LL but with a very small RR
and intermediate/large tan beta. Large LR mixing requires specific patterns for
trilinear A-terms, while LL mixing seems quite natural and easier to obtain. We
present an example for this class of models and show how it can accommodate the
current CP asymmetries experimental results.


title: Superheavy dark matter and ultrahigh energy cosmic rays

abstract:
  The phase of inflationary expansion in the early universe produces superheavy
relics in a mass window between 10^{12} GeV and 10^{14} GeV. Decay or
annihilation of these superheavy relics can explain the observed ultrahigh
energy cosmic rays beyond the Greisen-Zatsepin-Kuzmin cutoff. We emphasize that
the pattern of cosmic ray arrival directions with energies beyond 20 EeV will
decide between the different proposals for the origin of ultrahigh energy
cosmic rays.


title:
Has saturation physics been observed in deuteron-gold collisions at
  RHIC?

abstract:
  In the framework of the recently proposed saturation picture, we examine in a
systematic way whether the nuclear modification factor measured for d-Au
collisions at RHIC may be simply explained. The Cronin peak which is obtained
at mid-rapidity around $k_{\bot}\simeq 3$ GeV may be reproduced at the proper
height only by boosting the saturation momentum by an additional nuclear
component as already shown in the literature. In this respect, mid-rapidity
RHIC data cannot necessarily be seen as a probe of the saturation picture. The
large rapidity ($\eta\simeq 3$) region allows us to test the shape of the
unintegrated gluon distribution in the nucleus, investigating various
parameterizations inspired by large rapidity solutions (of the BFKL and) of the
Balitsky-Kovchegov (BK) equation. A satisfactory description of $R_{CP}$ at
RHIC is obtained in the BK picture.


title: Lightest Neutralino in Extensions of the MSSM

abstract:
  We study neutralino sectors in extensions of the MSSM that dynamically
generate the mu-term. The extra neutralino states are superpartners of the
Higgs singlets and/or additional gauge bosons. The extended models may have
distinct lightest neutralino properties which can have important influences on
their phenomenology. We consider constraints on the lightest neutralino from
LEP, Tevatron, and (g-2)_mu measurements and the relic density of the dark
matter. The lightest neutralino can be extremely light and/or dominated by its
singlino component which does not couple directly to SM particles except Higgs
doublets.


title:
Contributions from Goldstone-boson-exchange to baryon spectra in the MIT
  Bag Model

abstract:
  We discuss contributions of chiral bosons to baryon spectra in the MIT bag
model. It is believed that within hadrons, chiral bosons are degrees of freedom
which are independent of gluons to provide strong interactions between quarks.
In the original MIT bag model, only interaction mediated by gluon exchanges was
considered, by contrast, in this work we take into account the interaction
mediated by the exchanges of chiral bosons $\sigma$ and $\pi^{(\pm,0)}$. Then
following the standard approach, we minimize the effective hamiltonian which
includes both the contributions from gluon and chiral-boson exchanges with
respect to the bag radius to obtain the effective radius. By re-fitting the
spectra of baryons, we find that the contributions from the boson-exchange may
be 40% of that from gluon-exchanges and meanwhile the bag constant $B$, the
zero-point energy $z_0$ almost do not change. It indicates that in the original
version of the MIT bag model, the intermediate-distance interaction due to the
chiral-boson exchanges is attributed into the effective coupling $\alpha_c$
which stood for the short-distance interaction caused by the gluon exchanges
and the long-distance effects reflected by $B$ and $z_0$ are not influenced.


title: Little SUSY hierarchy in mixed modulus-anomaly mediation

abstract:
  Motivated by the KKLT string compactification involving a
supersymmetry-breaking uplifting potential, we examine 4D effective
supergravity with a generic form of uplifting potential, focusing on the
possibility that the resulting mixed modulus-anomaly mediated soft terms
realize the little hierarchy between the Higgs boson masses $m_H$ and the
sparticle masses $m_{SUSY}$. It is noted that for some type of uplifting
potential, the anomaly-mediated contribution to $m_H^2$ at $M_{GUT}$ can cancel
the subsequent renormalization group evolution of $m_H^2$ down to TeV scale,
thereby the model can naturally realize the little hierarchy $m_H^2\sim
m_{SUSY}^2/8\pi^2$ which is desirable for the lightest Higgs boson mass to
satisfy the experimental bound. In such models, the other Higgs mass parameters
$\mu$ and $B$ can have the desirable size $\mu \sim B \sim m_H$ without severe
fine-tuning of parameters, although the gravitino is much heavier than the
Higgs boson. Those models for the little hierarchy avoid naturally the
dangerous SUSY flavor and CP violations, and predict nearly degenerate low
energy gaugino masses, pure Higgsino LSP, and also a specific relation between
the stop and gaugino masses.


title: Efficacious Additions to the Standard Model

abstract:
  If split supersymmetry can be advocated as a means to have gauge-coupling
unification as well as dark matter, another plausible scenario is to enlarge
judiciously the particle content of the Standard Model to achieve the same
goals without supersymmetry. A simple efficacious example is presented.


title: A Maximal Atmospheric Mixing from a Maximal CP Violating Phase

abstract:
  We point out an elegant mechanism to predict a maximal atmospheric angle,
which is based on a maximal CP violating phase difference between second and
third lepton families in the flavour symmetry basis. In this framework, a
discussion of the predictions for theta_{12}, |U_{e3}|, delta and their
possible correlations is provided. We also present an explicit realisation in
terms of an SO(3) flavour symmetry model.


title:
Branching Ratio and Polarization of $B\to\rho(\omega)\rho(\omega)$
  Decays in Perturbative QCD Approach

abstract:
  In this work, we calculated the branching ratios, polarization fractions and
CP asymmetry of decay modes $B\to\rho(\omega)\rho(\omega)$ in the Perturbative
QCD approach, which is based on $\mathbf{k}_T$ factorization. After
calculation, we find the the branching ratios of $B^0 \to \rho^+ \rho^-$, $B^+
\to \rho^+ \rho^0$ and $B^+ \to \rho^+ \omega$ are at the order of $10^{-5}$,
and their longitudinal polarization fractions are more than 90%. The above
results agree with BarBar's measurements. We also predict the branching ratios
and polarizations of $B^0 \to \rho^0 \rho^0$, $B^0 \to \rho^0 \omega$ and $B^0
\to \omega \omega$, which will be measured in future. We predicted the CP
asymmetry of $B^0 \to \rho^+ \rho^-$ and $B^+ \to \rho^+ \rho^0$, which will
play important role in determining angle $\alpha$.


title: Model independent analysis of a class of $\bar{B}_s^0 $ decay modes

abstract:
  The widths of a class of two-body $\bar{B}_s^0 $ decays induced by $b \to c
\bar u d$ and $b \to c \bar u s$ transitions are determined in a
model-independent way, using $SU(3)_F$ symmetry and existing information on
$\bar B \to D_{(s)} P$ and $\bar B \to D_{(s)} V$ decays, with $P$ and $V$ a
light pseudoscalar or vector meson. The results are relevant for the $B_s$
physics programmes at the hadron colliders and at the $e^+ e^-$ factories
running at the peak of $\Upsilon(5S)$.


title: Measurement of three-family neutrino mixing and search for CP violation

abstract:
  The measurements of the parameters of the neutrino mixing matrix in the
present and future neutrino oscillation experiments at accelerators are
presented. The perspectives for high intensity new neutrino facilities as
SuperBeams, BetaBeams and Neutrino Factories devoted to precise measurements
subleading numu to nue oscillation parameters at the atmospheric scale are
discussed. Emphasis is on the determination of the currently unknown 1-3 sector
of the leptonic mixing matrix (i.e. the mixing between the first and third
generation and the CP violating Dirac phase) and on possible experimental
programs to be developed in Europe.


title: Polymer Chains and Baryons in a Strongly Coupled Quark-Gluon Plasma

abstract:
  Recently there was a significant change of views on physical properties and
underlying dynamics of Quark-Gluon Plasma at $T=170-350 MeV$, produced in heavy
ion collisions at RHIC. Instead of being a gas of $q,g$ quasiparticles, a
near-perfect liquid is observed. Also, precisely in this temperature interval,
the interaction deduced from lattice studies is strong enough to support
multiple binary bound states. This work is the first variational study of {\em
multibody} bound states. We will consider: (i) ``polymer chains'' of the type
$\bar q g g ..g q$; (ii) baryons $(qqq)$; (iii) closed (3-)chains of gluons
$(ggg)$. We found that chains (i) form in exactly the same $T$ range as binary
states, with the same binding {\em per bond}. The binding and $T$-range for
diquarks, baryons and closed 3-chains are also established. We point out that
the presence of chains, or possibly even a chain network, may drastically
change the transport properties of matter, such as charm diffusion or jet
energy loss. We further suggest that it seems to exist only for $T=(1-1.5)T_c$
and thus there may be a ``latent period'' for charm/jet quenching in RHIC
collisions, while matter cools down to such $T$.


title:
Erratum: Atomic Mass Dependence of Hadron Production in Deep Inelastic
  Scattering on Nuclei

abstract: Erratum to hep-ph/0502072


title: TeV Scale Leptogenesis, theta_13 And Doubly Charged Particles At LHC

abstract:
  We explore a realistic supersymmetric SU(2)_L \times SU(2)_R \times U(1)_B-L
model spontaneously broken at around 10^12 GeV. The presence of D and F-flat
directions gives rise to TeV mass doubly charged particles which can be found
at the LHC. We implement TeV scale leptogenesis and employing both type I and
II seesaw, the three light neutrinos are partially degenerate with masses in
the 0.02-0.1 eV range. The effective mass parameter for neutrinoless double
beta decay is 0.03-0.05 eV. We also find the interesting relation tan 2
\theta_13 ~ [\Delta m^2_{\odot} / \Delta m^2_{atm}] [sin 2 \theta_12 /tan 2
\theta_23] <~ 0.02.


title: Skyrme model and Isospin Chemical Potential

abstract:
  We discuss the stability of the Skyrmion solution in the presence of a finite
isospin chemical potential $\mu$. Solving numerically the mass of the Skyrmion
as function of $\mu$, we find a critical value $\mu_c=222.8$ MeV where the
Skyrmion mass vanishes. We compare the exact numerical treatment with an
analytical discussion based on a special shape for the profile of the Skyrmion
due to Atiyah and Manton. The extension of this ansatz for finite $\mu$ works
quite well for $\mu<121$ MeV. Then, for small values of $\mu$, where the
analytical approach is valid, we consider the possibility of having an angular
deformation for the Skyrmionic profile, which is possible for finite values of
$\mu$. This is however, a small effect. Finally we introduce finite temperature
corrections, which strength the instability induced by the chemical potential,
finding the dependence of the critical temperature on $\mu$.


title: Excellent approximate solution to the mysterious mass equation by Koide

abstract:
  It is shown that the efficient mass formula we found for charged leptons in
1992 can be considered as an excellent approximate solution to the mysterious
charged-lepton mass equation proposed by Koide in 1981.


title: A unitarity analysis on the I=0 $d$ wave $\pi\pi$ scattering amplitude

abstract:
  We study I=0 $d$ wave $\pi\pi$ scattering phase shift using a proper
unitarization approach. It is verified that the $f_2(1270)$ resonance
corresponds to a twin pole structure: one on the second sheet, another one on
the third sheet. Also we find fair agreement on $f_2(1270)$ pole's mass and
width between our results and the PDG values. Besides, our analysis reveals the
existence of a virtual state in this channel. Its pole location is determined
by fitting experimental data and it is found to be in good agreement with the
prediction from chiral perturbation theory. Our analysis demonstrates that
partial wave amplitudes calculated in chiral perturbation theory are reliable
in the small $|s|$ region, contrary to some unitarization models.


title: Resolution to the B -> pi K puzzle

abstract:
  We calculate the important next-to-leading-order contributions to the B -> pi
K, pi pi decays from the vertex corrections, the quark loops, and the magnetic
penguins in the perturbative QCD approach. It is found that the latter two
reduce the leading-order penguin amplitudes by about 10%, and modify only the B
-> pi K branching ratios. The main effect of the vertex corrections is to
increase the small color-suppressed tree amplitude by a factor of 3, which then
resolves the large difference between the direct CP asymmetries of the B^0 ->
pi^\mp K^\pm and B^\pm -> pi^0 K^\pm modes. The puzzle from the large B^0 ->
pi^0 pi^0 branching ratio still remains.


title: Searching for effects of Spatial Noncommutativity via a Penning Trap

abstract:
  The possibility of testing spatial noncommutativity via a Penning trap is
explored. The case of both space-space and momentum-momentum noncommuting is
considered. Spatial noncommutativity leads to the spectrum of the orbital
angular momentum of a Penning trap possessing fractional values, and in the
limits of vanishing kinetic energy and subsequent vanishing magnetic field,
this system has non-trivial dynamics. The dominant value of the lowest orbital
angular momentum is $\hbar/4$, which is a clear signal of spatial
noncommutativity. An experimental verification of this prediction by a
Stern-Gerlach-type experiment is suggested.


title:
Production and FCNC decay of supersymmetric Higgs bosons into heavy
  quarks in the LHC

abstract:
  We analyze the production and subsequent decay of the neutral MSSM Higgs
bosons (h = h^0, H^0, A^0) mediated by flavor changing neutral currents (FCNC)
in the LHC collider. We have computed the h-production cross-section times the
FCNC branching ratio, \sigma(pp -> h -> qq') = \sigma(pp -> h) B(h -> qq'), in
the LHC focusing on the strongly-interacting FCNC sector. Here qq' is an
electrically neutral pair of quarks of different flavors, the dominant modes
being those containing a heavy quark: tc or bs. We determine the maximum
production rates for each of these modes and identify the relevant regions of
the MSSM parameter space, after taking into account the severe restrictions
imposed by low energy FCNC processes. The analysis of \sigma(pp -> h -> qq')
singles out regions of the MSSM parameter space different from those obtained
by maximizing only the branching ratio, due to non-trivial correlations between
the parameters that maximize/minimize each isolated factor. The production
rates for the bs channel can be huge for a FCNC process (0.1-1 pb), but its
detection can be problematic. The production rates for the tc channel are more
modest (10^{-3}-10^{-2} pb), but its detection should be easier due to the
clear-cut top quark signature. A few thousand tc events could be collected in
the highest luminosity phase of the LHC, with no counterpart in the SM.


title:
Charged Lepton Corrections to Neutrino Mixing Angles and CP Phases
  Revisited

abstract:
  We re-analyze charged lepton corrections to neutrino mixing angles and CP
phases, carefully including CP phases from the charged lepton sector. We
present simple analytical formulae for including the charged lepton corrections
and derive compact new results for small neutrino and charged lepton mixings
$\theta^{\nu}_{13}$ and $\theta^{e}_{13}$. We find a generic relation
$\theta_{12} + \frac{1}{\sqrt{2}} \theta^{e}_{12} \cos(\delta - \pi) \approx
\theta^{\nu}_{12}$, which relates the prediction from the neutrino sector
$\theta^{\nu}_{12}$ to the charged lepton mixing $\theta^{e}_{12}$ and to the
MNS neutrino oscillation phase $\delta$. We apply our formula to the examples
of bimaximal or tri-bimaximal neutrino mixing. One implication is that the
so-called quark-lepton complementarity relation $\theta_{12} + \theta_C =
45^\circ$ can only hold for $\delta = \pi$ and it gets modified in the presence
of leptonic CP violation. On the other hand, the lepton mixing $\theta_{13}$
generated from the charged lepton correction $\theta^{e}_{12}$ is independent
of CP phases and given by $\theta_{13} = \frac{1}{\sqrt{2}} \theta^{e}_{12}$.
Combining these results leads to a model-independent sum rule: $\theta_{12} +
\theta_{13} \cos(\delta - \pi) \approx \theta^{\nu}_{12}$ where
$\theta^{\nu}_{12} = (35.26^\circ) 45^\circ$ in the case of (tri-)bimaximal
neutrino mixing, for example.


title:
Scalar sector of Supersymmetric ${SU}(3)_C\otimes {SU}(3)_L \otimes
  {U}(1)_N$ Model with right-handed neutrinos

abstract:
  We investigate a scalar sector of the supersymmetric $ SU_C(3) \otimes
SU_L(3)\otimes U_N(1)$ model with right-handed neutrinos. The mass spectra are
derived. We show that only neutral Higgs sector with lepton number L=0 could
have a VEV. There is no mixing between scalars having L=0 and bilepton scalars
having L=2. There are six Goldstone bosons: two in neutral sector, three in
pseudo-scalar sector and one in charged scalar sector. For a given set of input
parameters (five from the $F$ terms and two from the soft term) all the scalar
sectors in this model contain the upper limit of 230 GeV to the mass of the
lightest scalar, which are in agreement with the lower limit of the SM Higgs
boson obtained by LEP.


title: Using SU(3) Relations to bound the CP Asymmetries in $B \to KKK$ decays

abstract:
  We consider three body $\Delta s = 1$ $B \to f$ decays with $f=KKK$. The
deviations of $-\eta_f S_f$ from $S_{\psi K_S}$ and of $C_f$ from zero can be
bounded using the approximate SU(3) flavor symmetry of the strong interactions
and branching ratios of various $\Delta s = 0$ modes. We present the most
promising SU(3) amplitude relations that can be used to obtain these bounds.


title: A precise sum rule among four B -> Kpi CP asymmetries

abstract:
  A sum rule relation is proposed for direct CP asymmetries in $B\to K\pi$
decays. Leading terms are identical in the isospin symmetry limit, while
subleading terms are equal in the flavor SU(3) and heavy quark limits. The sum
rule predicts $A_{\rm CP}(B^0\to K^0\pi^0)=-0.17 \pm 0.06$ using current
asymmetry measurements for the other three $B\to K\pi$ decays. A violation of
the sum rule would be evidence for New Physics in $b\to s\bar qq$ transitions.


title: KamLAND results and the radiogenic terrestrial heat

abstract:
  We find that recent results from the KamLAND collaboration on geologically
produced antineutrinos, N(U+Th) = 28+16-15 events, correspond to a radiogenic
heat production from Uranium and Thorium decay chains H(U+Th) = 38+35-33 TW.
The 99% confidence limit on the geo-neutrino signal translates into the upper
bound H(U+Th) < 162 TW, which is much weaker than that claimed by KamLAND,
H(U+Th) < 60 TW, based on a too narrow class of geological models. We also
performed an analysis of KamLAND data including recent high precision
measurements of the C13(\alpha,n)O16 cross section. The result, N(U+Th) =
31+14-13, corroborates the evidence (approx 2.5\sigma) for geo-neutrinos in
KamLAND data.

categories: hep-ph astro-ph nucl-ex nucl-th physics.geo-ph


title: Neutrino geophysics with KamLAND and future prospects

abstract:
  The Kamioka liquid scintillator anti-neutrino detector (KamLAND) is a
low-energy and low-background neutrino detector which could be a useful probe
for determining the U and Th abundances of the Earth. We constructed a model of
the Earth in order to evaluate the rate of geologically produced anti-neutrinos
(geo-neutrinos) detectable by KamLAND. We found that KamLAND can be used to
determine the absolute abundances of U and Th in the Earth with an accuracy
sufficient for placing important constraints on Earth's accretional process and
succeeding thermal history. The present observation of geo-neutrinos with
KamLAND is consistent with our model prediction based on the bulk silicate
Earth (BSE) composition within the uncertainty of the measurement. If a
neutrino detector were to be built in Hawaii, where effects of the continental
crust would be negligible, it could be used to estimate the U and Th content in
the lower mantle and the core. Our calculation of the geo-neutrino event rate
on the Earth's surface indicates that geo-neutrino observation can provide key
information for testing the current models for the content and distribution of
U and Th in the Earth.


title: TeV leptogenesis in Z-prime models and its collider probe

abstract:
  We show that the U(1)-prime models linked with the seesaw mechanism at TeV
scale can lead to a successful baryogenesis through soft leptogenesis with a
resonant behavior in the B parameter. Such a consideration constrains the
Z-prime mass to be larger than 2-3 TeV depending on the seesaw scale and the
spharelon rate. Together with multi-TeV Z-prime, large sneutrino-antisneutrino
mixing and CP violating phenomena required by TeV leptogenesis could be
searched for in future colliders by observing the distinct same-sign
dilepton--dichargino as well as dislepton--diHiggs signatures.


title:
331 vector-like models with mirror fermions as a possible solution for
  the discrepancy in the b-quark asymmetries, and for the neutrino mass and
  mixing pattern

abstract:
  A general study of the fermionic structure of the 331 models with \beta
arbitrary shows the possibility of obtaining 331 vector-like models with mirror
fermions. On one hand, the existence of mirror fermions gives a possible way to
fit the discrepancy in the bottom quark asymmetries from the prediction of the
standard model. On the other hand, the vector-like nature of the model permits
to address the problem of the fermion mass hierarchy, and in particular the
problem of the neutrino mass and mixing pattern. Specifically, we consider a
model with four families and \beta =-1/\sqrt{3} where the additional family
corresponds to a mirror fermion of the third generation of the Standard Model.
We also show how to generate ansatzs about the mass matrices of the fermions
according to the phenomenology. In particular, it is possible to get a natural
fit for the neutrino hierarchical masses and mixing angles. Moreover, by means
of the mixing between the third quark family and its mirror fermion, a possible
solution for the A_{FB}^{b} discrepancy is obtained.


title:
Methane ionization chamber to search for spin-dependent dark matter
  interactions

abstract:
  A liquid-methane ionization chamber is proposed as a setup to search for
spin-dependent interactions of dark-matter particles with hydrogen


title: Normal and Special Models of Neutrino Masses and Mixings

abstract:
  One can make a distinction between "normal" and "special" models. For normal
models $\theta_{23}$ is not too close to maximal and $\theta_{13}$ is not too
small, typically a small power of the self-suggesting order parameter
$\sqrt{r}$, with $r=\Delta m_{sol}^2/\Delta m_{atm}^2 \sim 1/35$. Special
models are those where some symmetry or dynamical feature assures in a natural
way the near vanishing of $\theta_{13}$ and/or of $\theta_{23}- \pi/4$. Normal
models are conceptually more economical and much simpler to construct. Here we
focus on special models, in particular a recent one based on A4 discrete
symmetry and extra dimensions that leads in a natural way to a
Harrison-Perkins-Scott mixing matrix.


title:
Higgs-Mediated tau --> mu and tau --> e transitions in II Higgs doublet
  Model and Supersymmetry

abstract:
  We study the phenomenology of the mu-tau and e-tau lepton flavour violation
(LFV) in a general two Higgs Doublet Model (2HDM) including the supersymmetric
case. We consider several LFV decay modes of the charged fermion tau, namely
tau-> l_jgamma, tau->l_j l_k l_k and tau-> l_jeta. The predictions and the
correlations among the rates of the above processes are computed. In
particular, it is shown that tau->l_jgamma processes are the most sensitive
channels to Higgs-mediated LFV specially if the splitting among the neutral
Higgs bosons masses is not below the 10% level.


title: Three-Loop Results for Quark and Gluon Form Factors

abstract:
  We study the photon-quark-quark and Higgs-gluon-gluon form factors for
on-shell massless quarks and gluons in perturbative QCD. Previous third-order
results for the quark case are extended by calculating the fermion-loop
contributions up to the finite terms in dimensional regularization. For the
gluon case the complete set of infrared poles at three loops is derived. Using
the exponentiation of the form factor, the latter results are employed to
extract a function entering the infrared factorization of general third-order
amplitudes. We evaluate the infrared finite absolute ratio of the time-like and
space-like gluon form factors up to the fourth order in the strong coupling
constant. The result supports previous indications that the perturbative
expansion of the Higgs boson production rate at the LHC is under control.


title: Spontaneous CP and R parity breaking in supersymmetry

abstract:
  We show that a model where both CP and R-parity are spontaneously broken
exists. We study the electroweak symmetry breaking sector of the model and find
minima consistent with experimentally viable Higgs boson masses. We also
demonstrate that one can obtain neutrino masses and mixing angles within
measured values.


title:
Electroexcitation of nucleon resonances at Q^2=0.65 GeV/c^2 from a
  combined analysis of single- and double-pion electroproduction data

abstract:
  Data on single- and double-charged pion electroproduction off protons are
successfully described in the second and third nucleon resonance regions with
common N* photocouplings. The analysis was carried out using separate isobar
models for both reactions. From the combined analysis of two exclusive
channels, the gamma* p --> N*+ helicity amplitudes are obtained for the
resonances P11(1440), D13(1520), S31(1620), S11(1650), F15(1680), D33(1700),
D13(1700), and P13(1720) at Q2=0.65 GeV/c^2.


title: Multi-quark interactions with a globally stable vacuum

abstract:
  It is shown that $U(3)_L\times U(3)_R$ eight-quark interactions stabilize the
asymmetric ground state of the well-known model with four-quark Nambu --
Jona-Lasinio and six-quark 't Hooft interactions. The result remains when the
reduced SU(3) f\mbox{}lavour symmetry is explicitly broken by the general
current quark mass term with $\hat{m}_u\neq\hat{m}_d\neq\hat{m}_s$.


title: Spontaneous Leptogenesis in Brans-Dicke Cosmology

abstract:
  The role of the auxiliary scalar field $\phi$ of Brans-Dicke theory played in
baryon number asymmetry is discussed in this paper. We consider a derivative
coupling of this gravitational scalar field to the baryon current ${J^{\mu}}_B$
or the current of the baryon number minus lepton number ${J^{\mu}}_{B-L}$ based
on a series of works of R. Morganstern about the Brans-Dicke cosmology. We find
that the spontaneous baryogenesis by this coupling is capable to yield a
sufficient baryon asymmetry $n_B/s\sim 10^{10} $ for the time of the grand
unification is in a little advanced. In addition, Davoudiasl et al have
recently introduced a new type of interaction between the Ricci scalar $R$ and
the bayon current $J^{\mu}$, $\partial_{\mu}R J^{\mu}$ and also proposed a
mechanism for baryogenesis, the gravitational baryogenesis. However, the
Einstein equation tell us that $\dot{R}=0$ in the radiation-dominated epoch of
the standard FRW cosmology. In this paper we reconsider the feasibility of
having gravitational baryongenesis with such a form of interaction in
radiation-filled Brans-Dicke cosmology. We will show that $\dot{R}$ does not
vanish in this case and the required baryon number asymmetry can also be
achieved.


title:
Electromagnetic Nucleon-to-Delta Transition in Chiral Effective-Field
  Theory

abstract:
  We perform a relativistic chiral effective-field theory calculation of the
pion electroproduction off the nucleon ($e^- N \to e^- N \pi$) in the
Delta(1232)-resonance region. After fixing the three low-energy constants,
corresponding to the magnetic (M1), electric (E2), and Coulomb (C2) $\gamma
N\Delta $ couplings, our calculation provides a prediction for the
momentum-transfer and pion-mass dependence of the $\gamma N\Delta $ form
factors. The prediction for the pion-mass dependence resolves the discrepancy
between the recent lattice QCD results and the experimental value for the
"C2/M1 ratio" at low $Q^2$.


title:
Is it possible to predict the sign of the Matter-Antimatter Asymmetry in
  the Universe?

abstract:
  I investigate the possibility to define the sign of the leptonic asymmetry by
the low energy parameters. It is shown that in the context of the minimal
renormalizable SO(10) model the sign of the matter-antimatter asymmetry can be
defined by the leptonic mixing and masses in the case of Type II see-saw.


title: Isobar rescattering model and light scalar mesons

abstract:
  We use a toy model to discuss the problem of parameterizing the possible
contribution of a light scalar meson, sigma, to the final state interactions in
the non leptonic decays of heavy mesons.


title: Effects of Final-State Interactions in Hadronic B Decays

abstract:
  Final-state rescattering effects on the hadronic B decays and their impact on
direct and mixing-induced CP asymmetries are examined. Implications for some
phenomenologies are briefly discussed.


title: The antinucleon-nucleon quasi-bound states: J/psi and atomic evidence

abstract:
  The measurements of J/psi decays into photon, proton and antiproton show a
strong enhancement at the proton-antiproton threshold not seen in the decays
into neutral pion, proton and antiproton. What is the nature of this
enhancement? A natural interpretation can be performed in terms of a classical
model of nucleon-antinucleon interactions based on G-parity transformation. The
observed proton-antiproton structure is the consequence of the strong
attraction in the singlet S-wave state related predominantly to pion exchanges.
Similar attractions generate near threshold: an isospin-zero virtual (or
quasi-bound) state in singlet S-wave, an isospin-one quasi-bound state in
triplet P-wave with total angular momentum one and an isospin-zero resonance in
triplet P-wave with total angular momentum zero. These P-wave structures find
support in the antiproton-atomic data.


title: Top Mode Standard Model in Six Dimensions

abstract:
  We construct a top-mode standard model where the third generation fermions
and the SU(2)_L \times U(1)_Y gauge bosons are put on a 6-dimensional
brane(5-brane) with the extra dimensions compactified on the TeV
scale(R_5^{-1}=R_6^{-1} \equiv R^{-1}= 1-10 TeV), while only the gluons live in
a compactified 8-dimensional bulk(R_7^{-1}=R_8^{-1} \equiv \Lambda \gg
R^{-1}).On the 5-brane, Kaluza-Klein (KK) modes of the bulk gluons give rise to
induced four-fermion interactions which, combined with the gauge interactions,
are shown to be strong enough to trigger the top quark condensate, based on the
dynamics of 6-dimensional gauged Nambu-Jona-Lasinio (NJL) model. Moreover, we
can use a freedom of the brane positions to tune the four-fermion coupling
close to the critical line of 6-dimensional gauged NJL model, so that the gap
equation can ensure the top condensate on the weak scale while keeping other
fermions massless. There actually exists a scale (``tMAC scale''), \Lambda_{\rm
tM} = (7.8-11.0) R^{-1}, where the running gauge couplings combined with the
induced four-fermion interactions trigger only the top condensate while no
bottom and tau condensates. Furthermore, presence of such explicit four-fermion
interactions enables us to formulate straightforwardly the compositeness
conditions at \Lambda=\Lambda_{\rm tM}, which, through the
renormalization-group analysis, yields a prediction of masses of the top quark
and the Higgs boson, m_t = 177 - 187 GeV and m_H = 183 - 207 GeV.


title:
Regge behaviour of distribution functions and t and x-evolutions of
  gluon distribution function at low-x

abstract:
  In this paper t and x-evolutions of gluon distribution function from
Dokshitzer-Gribov-Lipatov-Altarelli-Parisi(DGLAP) evolution equation in leading
order(LO) at low-x, assuming the Regge behaviour of quark and gluon at this
limit, are presented. We compare our results of gluon distribution function
with MRST 2001, MRST 2004 and GRV '98 parameterizations and show the
compatibility of Regge behaviour of quark and gluon distribution functions with
perturbative quantum chromodynamics(PQCD) at low-x. We also discuss the
limitations of Taylor series expansion method used earlier to solve DGLAP
evolution equations, in the Regge behaviour of distribution functions.


title: Neutrino oscillations and new physics

abstract:
  I discuss the theoretical background and the status of neutrino oscillation
parameters from the current worlds' global data sample and latest flux
calculations. I give their allowed ranges, best fit values and discuss the
small parameters and sin2theta13, which characterize CP violation in neutrino
oscillations. I mention the significance of neutrinoless double beta decay and
current expectations in view of oscillation results.


title:
Transverse-momentum resummation and the spectrum of the Higgs boson at
  the LHC

abstract:
  We consider the transverse-momentum (q_T) distribution of generic high-mass
systems (lepton pairs, vector bosons, Higgs particles, ....) produced in hadron
collisions. At small q_T, we concentrate on the all-order resummation of the
logarithmically-enhanced contributions in QCD perturbation theory. We elaborate
on the $b$-space resummation formalism and introduce some novel features: the
large logarithmic contributions are systematically exponentiated in a
process-independent form and, after integration over q_T, they are constrained
by perturbative unitarity to give a vanishing contribution to the total cross
section. At intermediate and large q_T, resummation is consistently combined
with fixed-order perturbative results, to obtain predictions with uniform
theoretical accuracy over the entire range of transverse momenta. The formalism
is applied to Standard Model Higgs boson production at LHC energies. We combine
the most advanced perturbative information available at present for this
process: resummation up to next-to-next-to-leading logarithmic accuracy and
fixed-order perturbation theory up to next-to-leading order. The results show a
high stability with respect to perturbative QCD uncertainties.


title: Quasi-particle model of QGP - a revisit

abstract:
  The quasi-particle model of quark gluon plasma (QGP) is revisited here with
thermodynamically consistent formalism, different from earlier studies, without
the need of temperature dependent bag constant as well as other effects such as
confinement effects, effective degrees of freedom etc. Our model has only one
system dependent parameter and surpraisingly good fit to lattice results for
gluon plasma, 2-flavor and 3-flavor QGP are obtained. The basic idea is to
evaluate energy density $\epsilon$ first from grand partition function of
quasi-particle QGP and then derive all other thermodynamic functions from
$\epsilon$. Quasi-particles are assumed to have temperature dependent mass
equal to plasma frequency. Energy density, pressure and speed of sound are
evaluated and compared with available lattice data. We further extend the model
to finite chemical potential, without any new parameters, to obtain quark
density, quark susceptibility etc. and fits very well with the lattice results
on 2-flavor QGP.


title: Temperature of the inflaton and duration of inflation from WMAP data

abstract:
  If the initial state of the inflaton field is taken to have a thermal
distribution instead of the conventional zero particle vacuum state then the
curvature power spectrum gets modified by a temperature dependent factor such
that the fluctuation spectrum of the microwave background radiation is enhanced
at larger angles. We compare this modified cosmic microwave background spectrum
with Wilkinson microwave anisotropy probe data to obtain an upper bound on the
temperature of the inflaton at the time our current horizon crossed the horizon
during inflation. We further conclude that there must be additional e-foldings
of inflation beyond what is needed to solve the horizon problem.


title: Electromagnetic corrections to non-leptonic two-body B and D decays

abstract:
  We present analytic expressions to evaluate at O(alpha) the effects of
soft-photon emission, and the related virtual corrections, in non-leptonic
decays of the type B,D -> P1 P2, where P1 and P2 are scalar or pseudoscalar
particles. The phenomenological implications of these results are briefly
discussed. For B decays into charged pions the effects of soft-photon emission
are quite large: the corrections to the rates can easily exceed the 5% level if
tight cuts on the photon energy are applied.


title:
How strongly does dating meteorites constrain the time-dependence of the
  fine-structure constant?

abstract:
  We review our argument on the nature of the so-called meteorite constraint on
the possible time-dependence of the fine-structure constant, emphasizing that
dating meteorites at the present time is different in principle from searching
directly for the traces in the past, as in the Oklo phenomenon and the QSO
absorption lines. In the related literature, we still find some arguments not
necessarily consistent with this difference to be taken properly into account.
It does not immediately follow that any model-dependent approaches are useless
in practice, though we cannot help suspecting that dating meteorites is no
match for the Oklo and the QSO in probing the time-variability of the
fine-structure constant, at this moment. Some of the relevance to the QSO data
particularly in terms of the scalar field will be discussed.


title: Production and Decay of Saxion in $e^+e^-$ Collisions

abstract:
  The production of saxion in $e^{+}$$e^{-}$ collider and the saxion decay into
two photons were calculated in detail. Based on results it shows that the
saxion is stable in our universe and can play the role of the late decaying
particle (LDP) in a dark matter.


title: Multiplicity Difference between Heavy and Light Quark Jets Revisited

abstract:
  The perturbative QCD approach to multiparticle production predicts a
characteristic suppression of particle multiplicity in a heavy quark jet as
compared to a light quark jet. In the Modified Leading Logarithmic
Approximation (MLLA) the multiplicity difference \delta_{Q\ell} between heavy
and light quark jets is derived in terms of a few other experimentally measured
quantities. The earlier prediction for b-quarks needs revision in the light of
new experimental results and the improvement in the understanding of the
experimental data. We now find \delta_{b\ell}=4.4\pm0.4. The updated MLLA
results on \delta_{b\ell} and \delta_{c\ell} are compared with the present data
from e^+e^- annihilation. Their expected energy independence is confirmed
within the energy range between 29 and 200 GeV; the absolute values are now in
better agreement with experiment than in the previous analysis, and the
remaining difference can be attributed largely to next-to-MLLA contributions,
an important subset of which are identified and evaluated.


title:
Telltale Traces of U(1) Fields in Noncommutative Standard Model
  Extensions

abstract:
  Restrictions imposed by gauge invariance in noncommutative spaces together
with the effects of ultraviolet/infrared mixing lead to strong constraints on
possible candidates for a noncommutative extension of the Standard Model. In
this paper, we study a general class of 4-dimensional noncommutative models
consistent with these restrictions. Specifically we consider models based upon
a gauge theory with the gauge group U(N_1)\times U(N_2) \times ... \times
U(N_m) coupled to matter fields transforming in the (anti)-fundamental,
bi-fundamental and adjoint representations. Noncommutativity is introduced
using the Weyl-Moyal star-product approach on a continuous space-time. We pay
particular attention to overall trace-U(1) factors of the gauge group which are
affected by the ultraviolet/infrared mixing. We show that, in general, these
trace-U(1) gauge fields do not decouple sufficiently fast in the infrared, and
lead to sizable Lorentz symmetry violating effects in the low-energy effective
theory. Making these effects unobservable in the class of models we consider
would require pushing the constraint on the noncommutativity mass scale far
beyond the Planck mass (M_{NC}\gtrsim 10^{100} M_{P}) and severely limits the
phenomenological prospects of such models.


title:
An Effective Operators Analysis of Leptonic CP Violation : Bridging High
  and Low Energy Processes

abstract:
  We study the leptonic CP violation by employing the complete set of
dimension-six pure leptonic effective operators. Connection among the
observable at different energy scales can be made by the running of the
renormalization group equations. Explicitly, we study the charged lepton
electric dipole moment, muon Michel decay, and the triple spin-momentum
correlations at the Linear Collider. We found the electron electric dipole
moment, which starts at 2-loop level, severely constrains the possibilities to
detect the CP violating signatures in muon decay and at the linear colliders.


title: Heavy Majorana Neutrino Production at e- gamma Colliders

abstract:
  We study signatures of heavy Majorana neutrinos at e- gamma colliders. Since
these particles violate lepton number, they can give rise to the reactions e-
gamma -> W- W- e+ and e- gamma -> W+ mu- mu- nu. The Standard Model background
contains extra light neutrinos that escape detection, and can be reduced
significantly after imposing appropriate kinematical cuts. We analyze the
physics potential of an e- gamma collider, with centre of mass energies sqrt(s)
= 0.5--1 TeV and a total integrated luminosity of 100/fb, for detecting heavy
Majorana neutrinos with masses mN = 100--400 GeV. Assuming that heavy neutrinos
couple predominantly to one lepton flavour at a time, we find that 10 expected
background-free events can be established for |B_{eN}| >~ 4.6 x 10^{-3}.
Instead, if no signal is observed, this will imply that |B_{eN}| ~< 2.7 x
10^{-3} and |B_{\mu N}| ~< 0.05 at the 90% confidence level.


title: Properties of the Charmed P-wave Mesons

abstract:
  Two broad charmed mesons, the D_0^* and D_1', have recently been observed. We
examine the quark model predictions for the D_0^* and D_1' properties and
discuss experimental measurements that can shed light on them. We find that
these states are well described as the broad, j=1/2 non-strange charmed P-wave
mesons. Understanding the D_0^* and D_1' states can provide important insights
into the D_{sJ}^*(2317), D_{sJ}(2460) states whose unexpected properties have
led to renewed interest in hadron spectroscopy.


title: Reexamining $ B\to \pi\pi,\pi K$ Decays in QCD Factorization Approach

abstract:
  Motivated by the recent experimental data, we have revisited the $B\to \pi
K,\pi \pi$ decays in the framework of QCD factorization, with inclusion of the
important strong penguin corrections of order $\alpha_s^2$ induced by $b\to D
g^\ast g^\ast$ ($D=d$ or $s$ and $g^\ast$ denotes an off-shell gluon)
transitions. We find that these higher order strong penguin contributions can
provide $\sim 30%$ enhancement to the penguin-dominated $B\to \pi K$ decay
rates, and such an enhancement can improve the consistency between the
theoretical predictions and the experimental data significantly, while for the
tree-dominated $B\to \pi\pi$ decays, these higher order contributions play only
a minor role. When these strong penguin contributions are summed, only a small
strong phase remains and the direct CP asymmetries get small corrections. We
also find patterns of the ratios between the CP-averaged branching fractions
remain nearly unaffected even after including these higher order corrections
and the $\pi K$ puzzle still persists. Our results may indicate that to resolve
the puzzle one would have to resort to new physics contributions in the
electroweak penguin sector as found by Buras {\it et al}.


title:
Study of $B\to K^* \rho, K^*\omega$ Decays with Polarization in
  Perturbative QCD Approach

abstract:
  The $B \to K^{*}\rho$, $ K^{*}\omega$ decays are useful to determine the CKM
angle $\phi_3=\gamma$. Their polarization fractions are also interesting since
the polarization puzzle of the $B\to \phi K^*$ decay. We study these decays in
the perturbative QCD approach based on $k_T$ factorization.
  After calculating of the non-factorizable and annihilation type
contributions, in addition to the conventional factorizable contributions, we
find that the contributions from the annihilation diagrams are crucial. They
give dominant contribution to the strong phases and suppress the longitudinal
polarizations. Our results agree with the current existing data. We also
predict a sizable direct CP asymmetries in $B^+ \to K^{*+}\rho^0$, $B^0 \to
K^{*+}\rho^-$, and $B^+ \to K^{*+}\omega$ decays, which can be tested by the
oncoming measurements in the B factory experiments.