Relating B_s Mixing and B_s -> mu+mu- with New Physics

Abstract

We perform a study of the Standard Model (SM) fit to the mixing quantities $ΔM_{B_s}$, and $ΔΓ_{B_s}/ΔM_{B_s}$ in order to bound contributions of New Physics to $B_s$ mixing. We then use this to explore the branching fraction of $B_{s} \to μ^+μ^-$ in certain models of New Physics (NP). In most cases, this constrains NP amplitudes for $B_{s} \to μ^+μ^-$ to lie below the SM component.

27 pages, 5 figures; corrected misprints, updated numerical inputs and new references