57,639 research outputs found
Supersymmetric contributions to B --> K pi in the view of recent experimental result
Supersymmetric contributions to the branching ratios and CP asymmetries of
B--> K pi decays are analyzed in the view of recent experimental measurements.
We show that supersymmetry can still provide a natural solution to the apparent
discrepancy between theses results and the standard model expectations. We
emphasize that chargino contributions may enhance the electroweak penguin
effects that can resolve to the B--> K pi puzzle. We also point out that a
non-universal -terms is an essential requirement for this solution.Comment: 9 pages, 2 figure
CP violation in supersymmetric theories
We review the present status of CP violating problem in supersymmetric
extensions of the standard model. We analyze the constraints imposed by the
experimental limits of the electron, neutron, and mercury electric dipole
moments on the supersymmetric CP phases and show that only the scenarios with
flavour-off- diagonal CP violation remain attractive. These scenarios require
hermitian Yukawa matrices which naturally arise in models with left-right
symmetry or a SU(3) flavour symmetry. In this case, epsilon_K and
epsilon'/epsilon can be saturated by a small non-universality of the soft
scalar masses through the gluino and chargino contributions respectively. The
model also predicts a strong correlation between A_{CP}(b-> s gamma) and the
neutron electric dipole moment. In this framework, the standard model gives a
the leading contribution to the CP asymmetry in B ->psi K_S decay, while the
dominant chargino contribution to this asymmetry is < 0.2. Thus, no constraint
is set on the non-universality of this model by the recent BaBar and Belle
measureets.Comment: 34 pages, 10 figures. Invited review article for International
Journal of Modern Physics
Dark Left-Right Model: CDMS, LHC, etc
The Standard Model of particle interactions is extended to include fermion
doublets (n,e)_R transforming under the gauge group SU(2)_R such that n is a
Dirac scotino (dark-matter fermion), with odd R parity. Based on recent CDMS
data, it is shown how this new dark left-right model (DLRM2) favors a Z' gauge
boson at around 1 or 2 TeV and be observable at the LHC. The new W_R gauge
bosons may also contribute significantly to lepton-flavor-changing processes
such as mu to e gamma and mu-e conversion in a nucleus or muonic atom.Comment: 7 pages, 4 figures, typo corrected, talk at Dark Side of Universe
2010, Leon, Mexic
Heat flux of a granular gas with homogeneous temperature
A steady state of a granular gas with homogeneous granular temperature, no
mass flow, and nonzero heat flux is studied. The state is created by applying
an external position--dependent force or by enclosing the grains inside a
curved two--dimensional silo. At a macroscopic level, the state is identified
with one solution to the inelastic Navier--Stokes equations, due to the
coupling between the heat flux induced by the density gradient and the external
force. On the contrary, at the mesoscopic level, by exactly solving a BGK model
or the inelastic Boltzmann equation in an approximate way, a one--parametric
family of solutions is found. Molecular dynamics simulations of the system in
the quasi--elastic limit are in agreement with the theoretical results
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