# Muon decay - Type of interaction

Why does weak interaction occur when a muon decays? Why can't electromagnetic interaction occur when a muon decays?

$$\mu^- \rightarrow e^- + \gamma$$
• Neutrino mixing violates lepton flavour conservation. $\mu \to e \gamma$ is allowed but extremely suppressed. – dukwon Oct 19 '18 at 6:52