Measurements of Bc+ production and mass with the Bc+→J/ ψπ+ decay

Measurements of Bc+ production and mass are performed with the decay mode Bc+ -> J/Psi pi+ using 0.37 fb-1 of data collected in pp collisions at s = 7 TeV by the LHCb experiment. The ratio of the production cross-section times branching fraction between the Bc+ -> J/Psi pi+ and the B+ -> J/Psi K+ decays is measured to be (0.68+-0.10(stat.)+-0.03(syst.)+-0.05(lifetime))% for Bc+ and B+ mesons with transverse momenta pT > 4 GeV/c and pseudorapidities 2.5<4.5. The Bc+ mass is directly measured to be 6273.7+-1.3 (stat.)+-1.6(syst.) MeV/c2, and the measured mass difference with respect to the B+ meson is M(Bc+)-M(B+)=994.6+-1.3(stat)+-0.6(syst) MeV/c2.