Search for Lepton Flavour Violation in the Decay tau +/- to mu +/- gamma

A search for the lepton flavour violating decay {tau}{sup {+-}} {yields} {mu}{sup {+-}}{gamma} has been performed using 221.4 fb{sup -1} of data collected at an e{sup +}e{sup -} centre-of-mass energy of 10.58 GeV with the BABAR detector at the PEP-II storage ring. The search has an efficiency of 7.45 {+-} 0.65% for an expected background level of 6.2 {+-} 0.5 events. In the final sample 4 candidate events are selected. As there is no evidence for a signal in this data, for this preliminary result we set an upper limit of {Beta}({tau}{sup {+-}} {yields} {mu}{sup {+-}}{gamma}) < 9 x 10{sup -8} at 90% CL using the method of Feldman and Cousins.