Garra Ticó, JordiGraugés Pous, EugeniBABAR Collaboration2019-04-052019-04-052009-05-281550-7998https://hdl.handle.net/2445/131664We have performed a search for the rare leptonic decays B + → ℓ + ν ℓ ( l = e , μ ), using data collected at the Υ ( 4 S ) resonance by the BABAR detector at the PEP-II storage ring. In a sample of 468 × 10 6 B ¯¯¯ B pairs we find no evidence for a signal and set an upper limit on the branching fractions B ( B + → μ + ν μ ) < 1.0 × 10 − 6 and B ( B + → e + ν e ) < 1.9 × 10 − 6 at the 90% confidence level, using a Bayesian approach.9 p.application/pdfeng(c) American Physical Society, 2009Física de partículesExperimentsParticle physicsExperimentsinfo:eu-repo/semantics/article5777522019-04-05info:eu-repo/semantics/openAccess