τ→μγdecay in extensions with a vectorlike generation

Abstract

An analysis is given of the decay $\ensuremath{\tau}\ensuremath{\rightarrow}\ensuremath{\mu}+\ensuremath{\gamma}$ in minimal supersymmetric standard model extensions with a vectorlike generation. Here mixing with the mirrors allows the possibility of this decay. The analysis is done at one loop with the exchange of charginos and neutralinos and of sleptons and mirror sleptons in the loops. It is shown that a branching ratio $\mathcal{B}(\ensuremath{\tau}\ensuremath{\rightarrow}\ensuremath{\mu}\ensuremath{\gamma})$ in the range $4.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}\ensuremath{-}{10}^{\ensuremath{-}9}$ can be gotten which would be accessible to improved experiment such as at SuperB factories for this decay. The effects of $CP$ violation on this decay are also analyzed.