Garrido Beltrán, LluísLHCb Collaboration2023-04-192023-04-192013-01-011126-6708https://hdl.handle.net/2445/196916The decay B+ c → J/ψ K+ is observed for the first time using a data sample, corresponding to an integrated luminosity of 1.0 fb−1 , collected by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. A yield of 46 ± 12 events is reported, with a significance of 5.0 standard deviations. The ratio of the branching fraction of B+ c → J/ψ K+ to that of B+ c → J/ψ π+ is measured to be 0.069 ± 0.019 ± 0.005, where the first uncertainty is statistical and the second is systematic.14 p.application/pdfengcc by (c) Garrido Beltrán, Lluís et al., 2013http://creativecommons.org/licenses/by/3.0/es/Física de partículesExperimentsParticle physicsExperimentsinfo:eu-repo/semantics/article6844812023-04-19info:eu-repo/semantics/openAccess