99 research outputs found
On supersymmetric contributions to the CP asymmetry of the B -> phi K_S
We analyse the CP asymmetry of the B -> phi K_S process in general
supersymmetric models. In the framework of the mass insertion approximation, we
derive model independent limits for the mixing CP asymmetry. We show that
chromomagnetic type of operator may play an important role in accounting for
the deviation of the mixing CP asymmetry between B -> phi K_S and B -> J/psi
K_S processes observed by Belle and BaBar experiments. A possible correlation
between the direct and mixing CP asymmetry is also discussed. Finally, we apply
our result in minimal supergravity model and supersymmetric models with
non-universal soft terms.Comment: 19 pages, 3 figure
A nonlinear hydrodynamical approach to granular materials
We propose a nonlinear hydrodynamical model of granular materials. We show
how this model describes the formation of a sand pile from a homogeneous
distribution of material under gravity, and then discuss a simulation of a
rotating sandpile which shows, in qualitative agreement with experiment, a
static and dynamic angle of repose.Comment: 17 pages, 14 figures, RevTeX4; minor changes to wording and some
additional discussion. Accepted by Phys. Rev.
Charged lepton electric dipole moments with the localized leptons and the new Higgs doublet in the two Higgs doublet model
We study the lepton electric dipole moments in the split fermion scenario, in
the two Higgs doublet model, where the new Higgs scalars are localized around
the origin in the extra dimension, with the help of the localizer field. We
observe that the numerical value of the electron (muon, tau) electric dipole
moment is at the order of the magnitude of 10^{-31} (10^{-24}, 10^{-22}) (e-cm)
and this quantity is sensitive the new Higgs localization in the extra
dimension.Comment: 20 pages, 7 figure
Four Light Neutrinos in Singular Seesaw Mechanism with Abelian Flavor Symmetry
The four light neutrino scenario, which explains the atmosphere, solar and
LSND neutrino experiments, is studied in the framework of the seesaw mechanism.
By taking both the Dirac and Majorana mass matrix of neutrinos to be singular,
the four neutrino mass spectrum consisting of two almost degenerate pairs
separated by a mass gap eV is naturally generated. Moreover the
right-handed neutrino Majorana mass can be at GeV scale unlike
in the usual singular seesaw mechanism. Abelian flavor symmetry is used to
produce the required neutrino mass pattern. A specific example of the flavor
charge assignment is provided to show that maximal mixings between the
and are respectively attributed to the
atmosphere and solar neutrino anomalies while small mixing between two pairs to
the LSND results. The implication in the other fermion masses is also
discussed.Comment: Firnal version to appear in PR
B_s --> mu+ mu- decay in the R-parity violating minimal supergravity
We study B_s --> mu+ mu- in the context of the R-parity violating minimal
supergravity in the high tan beta regime. We find that the lowest value of the
branching ratio can go well below the present LHCb sensitivity and hence B_s
--> mu+ mu- can even be invisible to the LHC. We also find that the present
upper bound on Br(B_s --> mu+ mu-) puts strong constraint on the minimal
supergravity parameter space. The constraints become more severe if the upper
bound is close to its standard model prediction.Comment: 18 pages, 10 figures; version to be published in European Physical
Journal
Effect of FCNC mediated Z boson on lepton flavor violating decays
We study the three body lepton flavor violating (LFV) decays , and the semileptonic decay in the flavor changing neutral current (FCNC) mediated boson
model. We also calculate the branching ratios for LFV leptonic B decays,
, , and the
conversion of muon to electron in Ti nucleus. The new physics parameter space
is constrained by using the experimental limits on and
. We find that the branching ratios for and processes could be as large as and . For other LFV B decays the branching ratios are found to be too
small to be observed in the near future.Comment: 15 pages, 8 figures, typos corrected, one more section added, version
to appear in EPJ
Lepton polarization correlations in
In this work we will study the polarizations of both leptons () in the
decay channel . In the case of the dileptonic inclusive
decay , where apart from the polarization asymmetries
of single lepton , one can also observe the polarization asymmetries of
both leptons simultaneously. If this sort of measurement is possible then we
can have, apart from decay rate, FB asymmetry and the six single lepton
polarization asymmetries (three each for and ), nine more
double polarization asymmetries. This will give us a very useful tool in more
strict testing of SM and the physics beyond. We discuss the double polarization
asymmetries of leptons in the decay mode within
the SM and the Minimal Supersymmetric extensions of it.Comment: 21 pages, 21 figures; version to match paper to appear in PR
T-odd correlation in the K+ ->pi l nu gamma decays beyond Standard Model
The dependence of the T-odd correlation on the effective Lagrangian
parameters in the decays is analyzed. It
is shown that the introduced observable is perspective in a search for new
physics in the vector and pseudovector sector of the Lagrangian. As for scalar
and pseudoscalar sectors, the T-odd correlation studies will not allow one to
improve current restrictions on parameters of models beyond SM.Comment: 18 pages, 1 figur
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