Is theτa Paraelectron?

Abstract

I show that the equality of the rates for $\tau \to {\mu }^{+}+\mathrm{neutrinos}$ and ${\tau }^{+}\to e^{+}+\mathrm{neutrinos}$ does not necessarily exclude the possibility that ${\tau }^{+}$ is a paraelectron with the same lepton number as $e^{-}$, but it does require some rather unconventional decay matrix element. Different matrix elements predict different values for Michel $\rho$ parameters and daughter lepton helicities; tests for the paraelectron assignment occur in $e^{+}{e}^{-}$ annihilation.