Badalov, AlexeyCalvo Gómez, MíriamCamboni, AlessandroComerma Montells, AlbertGarrido Beltrán, LluísGascón Fora, DavidGraciani Díaz, RicardoGraugés Pous, EugeniOyanguren Campos, Arantza dePicatoste Olloqui, EduardoPotterat, CédricRives Molina, Vicente JoséRuiz, Hugo (Ruiz Pérez)Ruiz Valls, PabloVilasis-Cardona, XavierLHCb Collaboration2019-05-132019-05-132014-04-030031-9007https://hdl.handle.net/2445/133072A search for heavy Majorana neutrinos produced in the B − → π + μ − μ − decay mode is performed using 3     fb − 1 of integrated luminosity collected with the LHCb detector in p p collisions at center-of-mass energies of 7 and 8 TeV at the LHC. Neutrinos with masses in the range 250 to 5000 MeV and lifetimes from zero to 1000 ps are probed. In the absence of a signal, upper limits are set on the branching fraction B ( B − → π + μ − μ − ) as functions of neutrino mass and lifetime. These limits are on the order of 10 − 9 for short neutrino lifetimes of 1 ps or less. Limits are also set on the coupling between the muon and a possible fourth-generation neutrino.8 p.application/pdfengcc by (c) CERN; LHCb Collaboration, 2014http://creativecommons.org/licenses/by/3.0/es/Física de partículesExperimentsParticle physicsExperimentsinfo:eu-repo/semantics/article6457762019-05-13info:eu-repo/semantics/openAccess