Flavour violating - decays in magnetic interaction and $E_6$ models

Özet

In the view of future $c - \tau$-factories, we report an analysis of the rare decays of the $\tau$ lepton via $\tau \to \mu e \overline{e}, \tau \to e \mu \overline{\mu}, \tau \to \mu \mu \overline{\mu}$ and $\tau \to ee \overline{e}$ in the two models, i.e., in Barut's magnetic interaction model (MIM) and in an $E_6$ model proposed by Gürsey and his collaborators. The energy distributions of one of the final leptons are given for both models. Numerical estimates reveal that these decays can be as large as $10^{-6}$, which may be observed in LEP experiments or at other $c - \tau$ factories.