Constraints from the decay Bs0→μ+μ− and LHC limits on Supersymmetry

The pure leptonic decay Bs0→μ+μ− is strongly suppressed in the Standard Model (SM), but can have large enhancements in Supersymmetry, especially at large values of β. New limits on this decay channel from recent LHC data have been used to claim that these limits restrict the SUSY parameter space even more than the direct searches. However, direct searches are hardly dependent on tanβ, while Br(Bs0→μ+μ−) is proportional to tan6β. The relic density constraint requires large tanβ in a large region of the parameter space, which can lead to large values of Bs0→μ+μ−. Nevertheless, the experimental upper limit on Br(Bs0→μ+μ−) is not constraining the parameter space of the CMSSM more than the direct searches and the present Higgs limits, if combined with the relic density. We also observe SUSY parameter regions with negative interferences, where the Bs0→μ+μ− value is up to a factor three below the SM expectation, even at large values of tanβ.