Brief review of the searches for the rare decays $B^0_s \rightarrow \mu^+ \mu^-$ and $B^0 \rightarrow \mu^+ \mu^-$

TL;DR

This paper reviews the latest experimental searches for the rare decays of B mesons into muon pairs, highlighting recent measurements and their implications for physics beyond the Standard Model.

Contribution

It provides a comprehensive overview of recent experimental results from major collaborations and discusses their impact on constraining new physics models.

Findings

Combined upper limits on branching fractions: 4.2×10⁻⁹ for Bₛ⁰ and 0.8×10⁻⁹ for B⁰.

Most sensitive measurements from CDF, ATLAS, CMS, and LHCb.

Implications for extensions of the Standard Model, especially in scalar and pseudoscalar sectors.

Abstract

The current experimental status of the searches for the very rare decays $B^0_s \rightarrow \mu^+ \mu^-$ and $B^0 \rightarrow \mu^+ \mu^-$ is discussed. These channels are highly sensitive to various extensions of the Standard Model, specially in the scalar and pseudoscalar sector. The recent, most sensitive measurements from the CDF, ATLAS, CMS and LHCb collaborations are discussed and the combined upper exclusion limit on the branching fractions determined by the LHC experiments is shown to be $4.2\times 10^{-9}$ for $B^0_s \rightarrow \mu^+ \mu^-$ and $0.8\times 10^{-9}$ for $B^0 \rightarrow \mu^+ \mu^-$. The implications of these tight bounds on a selected set of New Physics models is sketched.