$B_s^0\to {\mu }^{+}{\mu }^{-}$ at LHC

Abstract

Rare leptonic decays of $B_{(s)}^0$ mesons are sensitive probes of New Physics effects. A combination of the CMS and LHCb analyses on the search of the rare decays $B_s^0\to {\mu }^{+}{\mu }^{-}$ and $B^0\to {\mu }^{+}{\mu }^{-}$ is presented. The branching fractions of $B_s^0\to {\mu }^{+}{\mu }^{-}$ and $B^0\to {\mu }^{+}{\mu }^{-}$ are measured to be $\mathcal{B}(B_s^0\to {\mu }^{+}{\mu }^{-})=(2.8{}_{-0.6}^{+0.7})\times 10^{-9}$ and $\mathcal{B}(B^0\to {\mu }^{+}{\mu }^{-})=(3.9{}_{-1.4}^{+1.6})\times 10^{-10}$ respectively. A statistical significances of $6.2\sigma$ is evaluated for $B_s^0\to {\mu }^{+}{\mu }^{-}$ from the Wilks' theorem while a significance of $3.0\sigma$ is measured for $B^0\to {\mu }^{+}{\mu }^{-}$ from the Feldman-Cousins procedure.

Proceedings of the 8th International Workshop on the CKM Unitarity Triangle (CKM 2014), Vienna, Austria, September 8-12, 2014