Observation of the suppressed decay ${\Lambda }_b^0\to p{\pi }^{-}{\mu }^{+}{\mu }^{-}$

LHCb collaboration, R. Aaij, B. Adeva +768

The suppressed decay ${\Lambda }_b^0\to p{\pi }^{-}{\mu }^{+}{\mu }^{-}$, excluding the $J/\psi$ and $\psi (2S)\to {\mu }^{+}{\mu }^{-}$ resonances, is observed for the first time with a significance o…