First observation and branching fraction measurement of the {Lambda}_b^0to {D}_s^{-}p decay

Abstract

The first observation of the {Lambda}_b^0to {D}_s^{-}p decay is presented using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of sqrt{s} = 13 TeV, corresponding to a total integrated luminosity of 6 fb−1. Using the {Lambda}_b^0to {Lambda}_c^{+}{pi}^{-} decay as the normalisation mode, the branching fraction of the {Lambda}_b^0to {D}_s^{-}p decay is measured to be mathcal{B}left({Lambda}_b^0to {D}_s^{-}pright)=left(12.6pm 0.5pm 0.3pm 1.2right)times {10}^{-6} , where the first uncertainty is statistical, the second systematic and the third due to uncertainties in the branching fractions of the {Lambda}_b^0to {Lambda}_c^{+}{pi}^{-} , {D}_s^{-}to {K}^{-}{K}^{+}{pi}^{-} and {Lambda}_c^{+}to p{K}^{-}{pi}^{+} decays.