# Search for the rare decay $B^{+} \rightarrow μ^{+}μ^{-}μ^{+}ν_{μ}$

collaboration, LHCb, Aaij, R, Beteta, C Abellán, Adeva, B, Adinolfi, M, Aidala, CA, Ajaltouni, Z, Akar, S, Albicocco, P, Albrecht, J
et al (show 839 more authors) (2019) Search for the rare decay $B^{+} \rightarrow μ^{+}μ^{-}μ^{+}ν_{μ}$. Eur. Phys. J. C, 79. 675 - 675.

A search for the rare leptonic decay $B^{+} \rightarrow {\mu}^{+}{\mu}^{-}{\mu}^{+}{\nu}_{{\mu}}$ 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.