The decays B+c→J/ψD+s and B+c→J/ψD*+s are observed for the first time using a dataset, corresponding to an integrated luminosity of 3 fb−1, collected by the LHCb experiment in proton-proton collisions at center-of-mass energies of s√=7 and 8 TeV. The statistical significance for both signals is in excess of 9 standard deviations. The following ratios of branching fractions are measured to be ℬ(B+c→J/ψD+s)/ℬ(B+c→J/ψπ+)=2.90±0.57±0.24, ℬ(B+c→J/ψD*+s)/ℬ(B+c→J/ψD+s)=2.37±0.56±0.10, where the first uncertainties are statistical and the second systematic. The mass of the B+c meson is measured to be mB+c=6276.28±1.44(stat)±0.36(syst) MeV/c2, using the B+c→J/ψD+s decay mode.
Observation of B-c(+) -> J/ psi D-s(+) and B-c(+) -> J/ psi D-s*(+) decays
CARDINALE, ROBERTA;FONTANELLI, FLAVIO;PATRIGNANI, CLAUDIA;PETROLINI, ALESSANDRO;SANNINO, MARIO;
2013-01-01
Abstract
The decays B+c→J/ψD+s and B+c→J/ψD*+s are observed for the first time using a dataset, corresponding to an integrated luminosity of 3 fb−1, collected by the LHCb experiment in proton-proton collisions at center-of-mass energies of s√=7 and 8 TeV. The statistical significance for both signals is in excess of 9 standard deviations. The following ratios of branching fractions are measured to be ℬ(B+c→J/ψD+s)/ℬ(B+c→J/ψπ+)=2.90±0.57±0.24, ℬ(B+c→J/ψD*+s)/ℬ(B+c→J/ψD+s)=2.37±0.56±0.10, where the first uncertainties are statistical and the second systematic. The mass of the B+c meson is measured to be mB+c=6276.28±1.44(stat)±0.36(syst) MeV/c2, using the B+c→J/ψD+s decay mode.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.