Problem 6.308

Which of the following processes are forbidden by the law of conservation of lepton charge: (1) \(n \rightarrow p+e^{-}+v\) (2) \(\pi^{+} \rightarrow \mu^{+}+e^{-}+e^{+}\) (3) \(\pi^{-} \rightarrow \mu^{-}+v\) (4) \(p+e^{-} \rightarrow n+v\) (5) \(\mu^{+} \rightarrow e^{+}+v+\tilde{v}\) (6) \(K^{-} \rightarrow \mu^{-}+\tilde{v} ?\)