Search for the rare decay $B^{+}\to {\mu }^{+}{\mu }^{-}{\mu }^{+}{\nu }_{\mu }$

Abstract

A search for the rare leptonic decay $B^{+}\to {\mu }^{+}{\mu }^{-}{\mu }^{+}{\nu }_{\mu }$ is performed using proton-proton collision data corresponding to an integrated luminosity of $4.7$ fb${}^{-1}$ collected by the LHCb experiment. The search is carried out in the region where the lowest of the two ${\mu }^{+}{\mu }^{-}$ mass combinations is below $980$MeV/c${}^2$. The data are consistent with the background-only hypothesis and an upper limit of $1.6\times 10^{-8}$ at 95% confidence level is set on the branching fraction in the stated kinematic region.

All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2018-037.html