Garra Ticó, JordiGraugés Pous, EugeniBABAR Collaboration2019-07-292019-07-292008-08-200031-9007https://hdl.handle.net/2445/138517We present a study of the decays B 0 , + → J / ψ ω K 0 , + using 383 × 10 6 B ¯¯¯ B events obtained with the BABAR detector at PEP-II. We observe Y ( 3940 ) → J / ψ ω , with mass 3914.6 + 3.8 − 3.4 ( stat ) ± 2.0 ( syst )     MeV / c 2 , and width 34 + 12 − 8 ( stat ) ± 5 ( syst )     MeV . The ratio of B 0 and B + decay to Y K is 0.27 + 0.28 − 0.23 ( stat ) + 0.04 − 0.01 ( syst ) , and the relevant B 0 and B + branching fractions are reported.7 p.application/pdfeng(c) American Physical Society, 2008Física de partículesExperimentsParticle physicsExperimentsinfo:eu-repo/semantics/article5777022019-07-29info:eu-repo/semantics/openAccess