Searches for lepton flavour and lepton number violation in $K^{+}$ decays at NA62

Joel Swallow, for the NA62 Collaboration

A search for the lepton number violating $K^{+}\to {\pi }^{-}{\mu }^{+}{e}^{+}$ and lepton flavour violating $K^{+}\to {\pi }^{+}{\mu }^{-}{e}^{+}$ decays is reported using NA62 data collect…