ausblenden:
Schlagwörter:
B Physics, Branching fraction, Hadron-Hadron Scattering
MPINP:
LHCb - Abteilung Hinton
Zusammenfassung:
A study of Bc+ → χcπ+ decays is reported using proton-proton collision data, collected with the LHCb detector at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb−1. The decay Bc+ → χc2π+ is observed for the first time, with a significance exceeding seven standard deviations. The relative branching fraction with respect to the Bc+ → J/ψπ+ decay is measured to be (BBc+ →χc2π+) / (BBc+ →J/ψπ+) = 0.37 ± 0.06 ± 0.02 ± 0.01, where the first uncertainty is statistical, the second is systematic, and the third is due to the knowledge of the χc2 → J/ψγ branching fraction. No significant Bc+ → χc1π+ signal is observed and an upper limit for the relative branching fraction for the Bc+ → χc1π+ and Bc+ → χc2π+ decays of (BBc+ →χc1π+) / (BBc+ →χc2π+) < 0.49 is set at the 90% confidence level.