First observation of a baryonic $B_s^0$ decay

Abstract

We report the first observation of a baryonic $B_s^0$ decay, $B_s^0\to p\overline{\hat{I}›}{K}^{-}$, using proton-proton collision data recorded by the LHCb experiment at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of $3.0{\mathrm{fb}}^{-1}$. The branching fraction is measured to be $\mathcal{B}(B_s^0\to p\overline{\hat{I}›}{K}^{-})+\mathcal{B}(B_s^0\to \bar{p}\hat{I}›K^{+})=\left[5.46\pm 0.61\pm 0.57\pm 0.50(\mathcal{B})\pm 0.32(f_s/f_d)\right]\times 10^{-6},$ where the first uncertainty is statistical and the second systematic, the third uncertainty accounts for the experimental uncertainty on the branching fraction of the $B^0\to p\overline{\hat{I}›}\ddot{I}{€}^{-}$ decay used for normalization, and the fourth uncertainty relates to the knowledge of the ratio of $b$-quark hadronization probabilities $f_s/f_d$.

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-2017-012.html