The decay B-c(+) -> J/psi 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 p p 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/psi K+ to that of B-c(+) -> J/psi pi(+) is measured to be 0.069 +/- 0.019 +/- 0 : 005, where the first uncertainty is statistical and the second is systematic.
Julia Schmale, Ivo Fabio Beck, Benjamin Jérémy Laurent Heutte, Nora Bergner, Hélène Paule Angot, Lubna Dada
Julia Schmale, Ivo Fabio Beck, Benjamin Jérémy Laurent Heutte, Lubna Dada
Nicolas Lawrence Etienne Longeard