Observation of $B_c^{+}\to D^0{K}^{+}$ decays

Abstract

Using proton-proton collision data corresponding to an integrated luminosity of 3.0 fb${}^{-1}$, recorded by the LHCb detector at centre-of-mass energies of 7 and 8 TeV, the $B_c^{+}\to D^0{K}^{+}$ decay is observed with a statistical significance of 5.1 standard deviations. By normalising to $B^{+}\to {\bar{D}}^0\ddot{I}{€}^{+}$ decays, a measurement of the branching fraction multiplied by the production rates for $B_c^{+}$ relative to $B^{+}$ mesons in the LHCb acceptance is obtained, $$R_{D^{0}K}=\frac{f_c}{f_u}\times \mathcal{B}(B_c^{+}\to D^0{K}^{+})=(9.3{}_{-2.5}^{+2.8}\pm 0.6)\times 10^{-7},$$ where the first uncertainty is statistical and the second is systematic. This decay is expected to proceed predominantly through weak annihilation and penguin amplitudes, and is the first $B_c^{+}$ decay of this nature to be observed.

All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-058.html