7,938 research outputs found
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
Dark Matter Annihilation and the PAMELA, FERMI and ATIC Anomalies
If dark matter (DM) annihilation accounts for the tantalizing excess of
cosmic ray electron/positrons, as reported by the PAMELA, ATIC, HESS and FERMI
observatories, then the implied annihilation cross section must be relatively
large. This results, in the context of standard cosmological models, in very
small relic DM abundances that are incompatible with astrophysical
observations. We explore possible resolutions to this apparent conflict in
terms of non-standard cosmological scenarios; plausibly allowing for large
cross sections, while maintaining relic abundances in accord with current
observations.Comment: 13 pages, 3 figures; published for publication in Physical Review
Flavour-Dependent CP Violation and Natural Suppression of the Electric Dipole Moments
We revisit the supersymmetric CP problem and find that it can be naturally
resolved if the origin of CP violation is closely related to the origin of
flavour structures. In this case, the supersymmetry breaking dynamics do not
bring in any new CP-violating phases. This mechanism requires hermitian Yukawa
matrices which naturally arise in models with a U(3) flavour symmetry. The
neutron electric dipole moment (NEDM) is predicted to be within one-two orders
of magnitude below the current experimental limit. The model also predicts a
strong correlation between A_{CP}(b --> s gamma)and the NEDM. The strong CP
problem is mitigated although not completely solved.Comment: revtex, 4 page
Supersymmetric origin of a low CP asymmetry
We show that general Minimal Supersymmetric extensions of the Standard Model
(MSSM) allow for a CP asymmetry in B --> J/psi K(S) well bellow the SM
expectations with dominant Supersymmetric contributions to epsilon_K and
epsilon'/epsilon. Indeed, we provide an explicit example of an MSSM with
non-universal soft breaking terms fully consistent with the low results of this
asymmetry recently announced by Babar and Belle collaborations.Comment: 6 pages, no figures. Reference added, typos correcte
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