Supersymmetry confronts Bs -> mu+mu-: Present and future status

Abstract

The purely leptonic rare decay B s → µ + µ − is very sensitive to supersymmetric contributions which are free from the helicity suppression of its Standard Model diagrams. The recent observation of the decay by the LHCb experiment and the first determination of its branching fraction motivate a review of their impact on the viable parameter space of supersymmetry. In this paper we discuss the implications of the present and expected future accuracy on BR(B s → µ + µ − ) for constrained and unconstrained MSSM scenarios, in relation to the results from direct SUSY searches and the Higgs data at the LHC. While the constraints from BR(B s → µ + µ − ) can be very important in specific SUSY regions, we show that the current result, and even foreseen future improvements in its accuracy, will leave a major fraction of the SUSY parameter space, compatible with the results of direct searches, unconstrained. We also highlight the complementarity of the B s → µ + µ − decay with direct SUSY searches.

Status of the charged Higgs boson in two Higgs doublet models

“…The decay B s → µ + µ − , which is very constraining in supersymmetric models [176,177], is sensitive to large values of λ µµ , λ bb and λ tt , and small charged Higgs masses. In the 2HDM, it constrains therefore mainly the low tan β region.…”

B_{s,d} -> l+ l- in the Standard Model with Reduced Theoretical Uncertainty

“…Ref. [1]). However, one of the key factors in determining the constraints is the SM prediction accuracy.…”

New physics contribution toBs→μ+μ−within R-parity violating supersymmetric models

“…Some of the popular SM extensions do predict indeed a negligible NP contribution to the B s → µ + µ − decay rate, due to strong correlations between the B s − B s mixing and B s → µ + µ − amplitudes [5]. Yet, for other SM extensions the problem of New Physics contribution to B s → µ + µ − in light of the recent observation of this decay by LHCb is the subject of discussion in the literature [2,[6][7][8][9]. In particular, it has been argued in [6][7][8] that the LHCb result still leaves room for a non-negligible NP contribution, due to the uncertainty in the experimental value of the B(B s → µ + µ − ).…”

“…Yet, for other SM extensions the problem of New Physics contribution to B s → µ + µ − in light of the recent observation of this decay by LHCb is the subject of discussion in the literature [2,[6][7][8][9]. In particular, it has been argued in [6][7][8] that the LHCb result still leaves room for a non-negligible NP contribution, due to the uncertainty in the experimental value of the B(B s → µ + µ − ).…”

“…1 may have a vanishing contribution to B s → µ + µ − . In addition, one should also take into account the impact of the R-conserving sector of the theory on the B s → µ + µ − transition amplitude as well [6]. Thus, in a realistic scenario one has different sources of a NP contribution to B s → µ + µ − that may in general interfere both constructively and destructively [28].…”