Analysis of the B s 0 $ B_s^0 $ → µ+µ– decay in the MSSM

Abstract

The first observation of the B s 0 $ B_s^0 $ → µ+µ– decay mode was reported by the CMS and LHCb collaboration. The small branching ratio inherent to this decay mode makes it highly sensitive for probing physics beyond the SM and we analyze this decay in the framework of the Minimal Supersymmetric Standard Model (MSSM). Complete analytical expressions for the decay amplitude at the one-loop order have been obtained with the aid of computational tools such as FeynArts and FeynCalc. The general recipe for utilising these computational tools to aid theoretical calculations in the MSSM is discussed. Working in the phenomenological MSSM with reduced parameter space, a simplification of the complete analytical expression was done to express the B s 0 $ B_s^0 $ → µ+µ– branching ratio as a function of these parameters. Numerical studies of the parametric dependence of B s 0 $ B_s^0 $ → µ+µ– branching ratio in the phenomenological MSSM can be easily performed with the obtained analytical expression.