Precision measurement of the $B_c^{+}$ 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 $9.0{\mathrm{fb}}^{-1}$. The $B_c^{+}$ mesons are reconstructed via the decays $B_c^{+}\to J/\psi {\pi }^{+}$, $B_c^{+}\to J/\psi {\pi }^{+}{\pi }^{-}{\pi }^{+}$, $B_c^{+}\to J/\psi p\bar{p}{\pi }^{+}$, $B_c^{+}\to J/\psi D_s^{+}$, $B_c^{+}\to J/\psi D^0{K}^{+}$ and $B_c^{+}\to B_s^0{\pi }^{+}$. Combining the results of the individual decay channels, the $B_c^{+}$ mass is measured to be $6274.47\pm 0.27(\mathrm{stat})\pm 0.17(\mathrm{syst})\mathrm{Me}\mathrm{V}/c^2$. This is the most precise measurement of the $B_c^{+}$ mass to date. The difference between the $B_c^{+}$ and $B_s^0$ meson masses is measured to be $907.75\pm 0.37(\mathrm{stat})\pm 0.27(\mathrm{syst})\mathrm{Me}\mathrm{V}/c^2$.

All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2020-003.html