Precision measurement of the Bc+ meson mass

Abstract

A precision measurement of the B+c meson mass is performed using proton- proton collision data collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to a total integrated luminosity of 9.0 fb−1. The B+c mesons are reconstructed via the decays B+c → J/ψπ+, B+c → J/ψπ+π−π+, B+c→J/ψpp¯¯¯π+, B+c→J/ψD+s, B+c → J/ψ D0K+ and B+c→B0sπ+. Combining the results of the individual decay channels, the B+c mass is measured to be 6274.47 ± 0.27 (stat) ± 0.17 (syst) MeV/c2. This is the most precise measurement of the B+c mass to date. The difference between the B+c and B0s meson masses is measured to be 907.75 ± 0.37 (stat) ± 0.27 (syst) MeV/c.