Search for $B$ meson decays to multimuon final states

Abstract

A search for decays of $B$ mesons to final states with four or six muons using $pp$ collision data recorded by the LHCb experiment corresponding to an integrated luminosity of $5.4{\text{fb}}^{-1}$ is presented. The decay modes of interest are $B_{(s)}^0\to {\mu }^{+}{\mu }^{-}{\mu }^{+}{\mu }^{-}$, $B^{+}\to K^{+}{\mu }^{+}{\mu }^{-}{\mu }^{+}{\mu }^{-}$, $B_{(s)}^0\to {\mu }^{+}{\mu }^{-}{\mu }^{+}{\mu }^{-}{\mu }^{+}{\mu }^{-}$ and $B^{+}\to K^{+}{\mu }^{+}{\mu }^{-}{\mu }^{+}{\mu }^{-}{\mu }^{+}{\mu }^{-}$, proceeding via both prompt and long-lived intermediate particles. No evidence for any of the signal modes is found, and upper limits spanning the range of $0.6\times 10^{-9}$ to $5.4\times 10^{-7}$ at the $95\%$ confidence level are set on their branching fractions, depending on the intermediate-particle masses and lifetimes. In addition, mass-integrated limits across the intermediate-particle lifetime ranges considered in this analysis are determined.

arXiv commentAll figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://lhcb-glance.cern.ch/alcm/public/analysis/full-details/5232/ (LHCb public pages)