It is because they are always very energetic. This, together with random quantum behavior, allows the “energetic-muon” to decay (not decompose) into different p

It is because they are always very energetic. This, together with random quantum behavior, allows the “energetic-muon” to decay (not decompose) into different particles (usually electron etc.). This is a quantum effect, and it is not a decomposition but the disappearing of the muon and the appearing of the others (+ a lot of energy in between, coming and going). An electron is an electron. However, when moving between orbitals in an atom, it “gets” a photon if it jumps “out”, it “loses” a photon when jumping “in”. But it is just an electron (with more or less energy).