Revisiting B_s\toμ^+μ^- and B\to K^{(*)}μ^+μ^- decays in the MSSM with and without R-parity

Abstract

The rare decays B_s -> μ^+μ^- and B -> K^{(*)}μ^+μ^- are sensitive to new particles and couplings via their interferences with the standard model contributions. Recently, the upper bound on B(B_s -> μ^+μ^-) has been improved significantly by the CMS, LHCb, CDF, and DØ experiments. Combining with the measurements of B(B-> K^{(*)}μ^+μ^-), we derive constraints on the relevant parameters of minimal supersymmetic standard model with and without R-parity, and examine their contributions to the dimuon forward-backward asymmetry in B-> K^{*}μ^+μ^- decay. We find that (i) the contribution of R-parity violating coupling products λ^{\prime}_{2i2}λ^{\prime*}_{2i3} due to squark exchange is comparable with the theoretical uncertainties in B-> K μ^+μ^- decay, but still could be significant in B-> K^{*}μ^+μ^- decay and could account for the forward-backward asymmetry in all dimuon invariant mass regions; (ii) the constrained mass insertion (δ^{u}_{LL})_{23} could have significant contribution to dA_{FB}(B-> K^{*}μ^+μ^-)/ds, and such effects are favored by thr recent results of the Belle, CDF, and LHCb experiments.