\cl{\bf $\tau\rightarrow\mu\mu{\bar\mu}$ and $\tau\rightarrow\mu e{\bar e}$ Decays in String Models with $\e6$ Symmetry

Abstract

A detailed analysis on the rare $\tau$ decay {\it via} $\taumue$ and $\taumus$ in the string models with $\e6$ symmetry is reported. It is found that $\Gamma(\taumue)\sim(6-7)\Gamma(\taumus)$ and these rates are in general about 1000 times less than that of $\Gamma(\mu\rightarrow e\gamma)$. It is also found that the out-going muon in $\taumue$ is almost 100\% right-handed polarized and the out-going electrons would be predominately parallel to each other. These decay processes may be accessible at the SSC.