Upper bound on the decay tau ->mu gamma from the Belle detector

Abstract

We have performed a search for the lepton-flavor-violating decay tau-->mugamma using a data sample of 86.3 fb(-1) accumulated by the Belle detector at KEK. No evidence for a signal is seen, and we set an upper limit for the branching fraction of B(tau-->mugamma) < 3.1x10(-7) at the 90% confidence level