Observation of the very rare ${\Sigma }^{+}\to p{\mu }^{+}{\mu }^{-}$ decay

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb +1131

The first observation of the ${\Sigma }^{+}\to p{\mu }^{+}{\mu }^{-}$ decay is reported with high significance using proton-proton collision data, corresponding to an integrated luminosity of $5.4\,\rm…