Precision measurement of the B c + $$ {B}_c^{+} $$ meson mass

Abstract A precision measurement of the B c + $$ {B}_c^{+} $$ 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 + $$ {B}_c^{+} $$ mesons are reconstructed via the decays B c + $$ {B}_c^{+} $$ → J/ψπ +, B c + $$ {B}_c^{+} $$ → J/ψπ + π − π +, B c + → J / ψp p ¯ π + $$ {B}_c^{+}\to J/\psi p\overline{p}{\pi}^{+} $$ , B c + → J / ψ D s + $$ {B}_c^{+}\to J/\psi {D}_s^{+} $$ , B c + $$ {B}_c^{+} $$ → J/ψ D 0 K + and B c + → B s 0 π + $$ {B}_c^{+}\to {B}_s^0{\pi}^{+} $$ . Combining the results of the individual decay channels, the B c + $$ {B}_c^{+} $$ mass is measured to be 6274.47 ± 0.27 (stat) ± 0.17 (syst) MeV/c 2. This is the most precise measurement of the B c + $$ {B}_c^{+} $$ mass to date. The difference between the B c + $$ {B}_c^{+} $$ and B s 0 $$ {B}_s^0 $$ meson masses is measured to be 907.75 ± 0.37 (stat) ± 0.27 (syst) MeV/c.