First observation and branching fraction measurement of the Λb0→Ds−p decay

Abstract

The first observation of the Λb0→Ds−p$$ {\Lambda}_b^0\to {D}_s^{-}p $$ decay is presented using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of s$$ \sqrt{s} $$ = 13 TeV, corresponding to a total integrated luminosity of 6 fb−1. Using the Λb0→Λc+π−$$ {\Lambda}_b^0\to {\Lambda}_c^{+}{\pi}^{-} $$ decay as the normalisation mode, the branching fraction of the Λb0→Ds−p$$ {\Lambda}_b^0\to {D}_s^{-}p $$ decay is measured to be BΛb0→Ds−p=12.6±0.5±0.3±1.2×10−6$$ \mathcal{B}\left({\Lambda}_b^0\to {D}_s^{-}p\right)=\left(12.6\pm 0.5\pm 0.3\pm 1.2\right)\times {10}^{-6} $$, where the first uncertainty is statistical, the second systematic and the third due to uncertainties in the branching fractions of the Λb0→Λc+π−$$ {\Lambda}_b^0\to {\Lambda}_c^{+}{\pi}^{-} $$, Ds−→K−K+π−$$ {D}_s^{-}\to {K}^{-}{K}^{+}{\pi}^{-} $$ and Λc+→pK−π+$$ {\Lambda}_c^{+}\to p{K}^{-}{\pi}^{+} $$ decays.