Measurements of B-c(+) production and mass are performed with the decay mode B-c(+) -> J/psi pi(+) using 0.37 fb(-1) of data collected in pp collisions at root s = 7 TeV by the LHCb experiment. The ratio of the production cross section times branching fraction between the B-c(+) -> 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 B-c(+) and B+ mesons with transverse momenta p(T) > 4 GeV/c and pseudorapidities 2.5 < eta < 4.5. The B-c(+) mass is directly measured to be 6273.7 +/- 1.3(stat) +/- 1.6(syst) MeV/c(2), and the measured mass difference with respect to the B+ meson is M(B-c(+)) - M(B+) = 994.6 +/- 1.3(stat) +/- 0.6(syst) MeV/c(2).
Jian Wang, Matthias Finger, Qian Wang, Yiming Li, João Miguel das Neves Duarte, Matthias Wolf, Varun Sharma, Yi Zhang, Tian Cheng, Yixing Chen, Alexis Kalogeropoulos, Ioannis Papadopoulos, Hua Zhang, Siyuan Wang, Xin Chen, Michele Bianco, Sebastiana Gianì, Sun Hee Kim, Rakesh Chawla, Jan Steggemann, Konstantin Androsov, Anna Mascellani, Federica Legger, Matteo Galli, Gabriele Grosso