PT Journal AU LHCb Collaboration (Aaij, Rea Garcia Martin, LM Henry, L Jashal, BK Martinez-Vidal, F Oyanguren, A Remon Alepuz, C Ruiz Vidal, J Sanchez Mayordomo, C TI Search for the rare decay B+ -> mu(+) mu(-) mu(+)nu(mu) SO European Physical Journal C JI Eur. Phys. J. C PY 2019 BP 675 - 12pp VL 79 IS 8 DI 10.1140/epjc/s10052-019-7112-x LA English AB A search for the rare leptonic decay B +. μ+ μ- μ+.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 μ+ μ- mass combinations is below 980 MeV/ c2. The data are consistent with the background- only hypothesis and an upper limit of 1.6x10 – 8 at 95% confidence level is set on the branching fraction in the stated kinematic region. ER