Search for lepton flavor violating decays tau- -> l- pi0, l- eta, l- eta'

Abstract

We have searched for lepton flavor violating semileptonic tau decays using a data sample of 153.8/fb accumulated with the Belle detector at the KEKB e+e- collider. For the six decay modes studied, the observed yield is compatible with the estimated background and the following upper limits are set at the 90% confidence level: B(tau- -> e- eta) < 2.3 x 10^-7, B(tau- -> mu- eta) < 1.5 x 10^-7, B(tau- -> e- pi0) < 1.9 x 10^-7, B(tau- -> mu- pi0) < 4.1 x 10^-7, B(tau- -> e- eta') < 10 x 10^-7, and B(tau- -> mu- eta') < 4.7 x 10^-7. These results are 10 to 64 times more restrictive than previous limits.