Search for lepton-flavor-violating τ decays into three leptons with 719 million produced τ+ τ- pairs

We present a search for lepton-flavor-violating τ decays into three leptons (electrons or muons) using 782 fb-1 of data collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. No evidence for these decays is observed and we set 90% confidence level upper limits on the branching fractions between 1.5 × 10- 8 and 2.7 × 10- 8. © 2010 Elsevier B.V.