Observation of the suppressed decay $Lambda^{0}_{b}rightarrow ppi^{-}mu^{+}mu^{-}$

The suppressed decay $Lambda^{0}_{b}rightarrow ppi^{-}mu^{+}mu^{-}$, excluding the $J/psi$ and $psi(2S)rightarrow mu^{+}mu^{-}$ resonances, is observed for the first time with a significance of 5.5 standard deviations. The analysis is performed with proton-proton collision data corresponding to an integrated luminosity of $3mathrm{fb}^{-1}$ collected with the LHCb experiment. The $Lambda^{0}_{b}rightarrow ppi^{-}mu^{+}mu^{-}$ branching fraction is measured relative to the $Lambda^{0}_{b}rightarrow J/psi(rightarrow mu^{+}mu^{-})ppi^{-}$ branching fraction giving begin{align} onumber frac{mathcal{B}(Lambda^{0}_{b}rightarrow ppi^{-}mu^{+}mu^{-})}{mathcal{B}({Lambda^{0}_{b}rightarrow J/psi(rightarrow mu^{+}mu^{-})ppi^{-}})} &= 0.044pm0.012pm0.007, end{align} where the first uncertainty is statistical and the second is systematic. This is the first observation of a $brightarrow d$ transition in a baryonic decay.