Heavy leptons, lepton mixing, and nonconservation of lepton-type number

Abstract

Introducing a new weak doublet of heavy leptons, one is led to a mixing of the various lepton states with respect to the weak interaction and subsequently to the violation of electron and muon number conservation (e.g., the decay μ→e γ). The new charged lepton can only decay via such a mixing and is therefore relatively long-lived ( τ>10 −11 sec). It can be produced singly in ν μ nucleus scattering at high energies. Various other phenomenological consequences are discussed.