Enhancement of Br(B_d -> mu^+mu^-)/Br(B_s -> mu^+mu^-) in Supersymmetric Unified Models

We explain the 2.3 sigma deviation in the recent measurements of the neutral B mesons decay into muon pairs from the standard model prediction in the framework of supersymmetric grand unified models using anti-symmetric coupling as a new source of flavor violation. We show a correlation between the B_d -> mu^+mu^- decay and the CP phase in the B_d -> J/psi K decay and that their deviations from the standard model predictions can be explained after satisfying constraints arising from various hadronic and leptonic rare decay processes, B-bar{B}, K-bar{K} oscillations data and electric dipole moments of electron and neutron. The allowed parameter space is typically represented by pseudoscalar Higgs mass m_A < 1 TeV and tan beta_H (= {v_u}/{v_d}) < 20 for squark and gluino masses around 2 TeV.Comment: 6 pages, 3 figure

Supersymmetric constraints from Bs -> mu+mu- and B -> K* mu+mu- observables

We study the implications of the recent LHCb limit and results on Bs -> mu+mu- and B -> K* mu+mu- observables in the constrained SUSY scenarios. After discussing the Standard Model predictions and carefully estimating the theoretical errors, we show the constraining power of these observables in CMSSM and NUHM. The latest limit on BR(Bs -> mu+mu-), being very close to the SM prediction, constrains strongly the large tan(beta) regime and we show that the various angular observables from B -> K* mu+mu- decay can provide complementary information in particular for moderate tan(beta) values.Comment: 30 pages, 14 figure

Faking Bs→μ+μ−B_s \to \mu^+\mu^-

Recent evidence from observation of the flavor-changing neutral current decay B_s to mu+ mu- by the LHCb collaboration B(B_s to mu^+ mu^-) = (3.2 * 10^{-9}), is consistent with the latest standard model prediction B(B_s to mu^+ mu^-) = (3.23 +- 0.27) * 10^{-9}. While New Physics can still affect this decay amplitude, its contribution is certainly not the dominant one. We analyze branching ratios of the decays B_s to mu+ mu- X, with X = a photon or neutrino anti-neutrino pair, which can mimic B_s to mu+ mu- on portions of the parameter space where X is soft. We perform a model-independent standard model calculation of those processes incorporating heavy quark and chiral symmetries of QCD. We show that the considered contributions contribute to B_s to mu+ mu- at a sub-percent level.Comment: 14 pages, 7 figures, .v2 changes : fixed diagram TeX, small notation change, fixed referenc