Enhanced lepton flavor violation with massless neutrinos: a study of muon and tau decays

Lepton flavor violating rates can be experimentally measurable even if the observed neutrinos are strictly massless. We make a study of the attainable rates for anomalous leptonic muon and tau number violating decays such as μ→eγ, μ→3e, τ→μγ, τ→eγ, τ→μμ+ μ−, τ→ ee+e−, τ→eμ+μ−, etc. as well as semileptonic lepton flavor violating tau decays such as τ→μπ0, τ→eπ0, τ→eη, etc. All muonic violating decays can be as large as the present limits from LAMPF, TRIUMF and PSI. The corresponding tau violating processes can all be at the limit of sensitivity of the upcoming τ factories