$\tau\to \mu \gamma$ Decay in Extensions with a Vector Like Generation
  An analysis is given of the decay $\tau \to \mu+ \gamma$ in MSSM extensions with a vector like 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 ${\cal B}(\tau\to \mu+\gamma)$ in the range $4.4\times 10^{-8} -10^{-9}$ 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. 
Tarek Ibrahim and Pran Nath
hep-ph hep-ex