17,157 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
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
A simple symmetry as a guide toward new physics beyond the Standard Model
There exists one experimental result that cannot be explained by the Standard
Model (SM), the current theoretical framework for particle physics: non-zero
masses for the neutrinos (elementary particles travelling close to light speed,
electrically neutral and weakly interacting). The SM assumes that they are
massless. Therefore, particle physicists are now exploring new physics beyond
the SM. There is strong anticipation that we are about to unravel it, in the
form of new matter and/or forces, at the Large Hadron Collider (LHC), presently
running at CERN. We discuss a minimal extension of the SM, based on a somewhat
larger version of its symmetry structure and particle content, that can
naturally explain the existence of neutrino masses while also predicting novel
signals accessible at the LHC, including a light Higgs boson, as evidenced by
current data.Comment: 5 pages: version to be published in Frontiers in High-Energy and
Astroparticle Physics following a change of title and minor changes to the
tex
The Supersymmetric Standard Model with Inverse Seesaw at the Large Hadron Collider
We review the TeV scale extension of the Minimal Supersymmetric
Standard Model (BLSSM) where an inverse seesaw mechanism of light neutrino mass
generation is naturally implemented and concentrate on its hallmark
manifestations at the Large Hadron Collider (LHC).Comment: 26 pages, 4 tables, 13 figures, to appear in Reports on Progress in
Physic
Upper bounds on SUSY contributions to b to s transitions from B_s - B_sbar mixing
We study the constraints on supersymmetric contributions to b to s
transitions from the recent allowed range and measurement of Bs-Bsbar mixing
obtained by the D0 and CDF collaborations at the Tevatron. We compute the upper
bounds on the relevant off-diagonal squark mass terms and compare them with the
bounds coming from Delta F=1 decays. We find that the constraints on
chirality-flipping mass insertions are unaffected. Conversely, the measurement
of Bs-Bsbar mixing is effective in constraining chirality-conserving mass
insertions, and it has striking effects in the case in which left- and
right-handed insertions have similar size. Finally, we discuss the phase of the
Bs-Bsbar mixing amplitude in the presence of SUSY contributions.Comment: 4 pages, 4 figures; v2: CDF measurement include
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
Chargino Contributions to Epsilon and Epsilon-Prime
We analyze the chargino contributions to the K-\bar K mixing and
epsilon-prime in the mass insertion approximation and derive the corresponding
bounds on the mass insertion parameters. We find that the chargino
contributions can significantly enlarge the regions of the parameter space
where CP violation can be fully supersymmetric. In principle, the observed
values of epsilon and epsilon-prime may be entirely due to the chargino --
up-squark loops.Comment: 9 pages, 2 figures, to appear in PL
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