Search for lepton flavor violating τ- decays into ℓ- η, ℓ- η′ and ℓ- π0

We have searched for lepton-flavor-violating τ decays with a pseudoscalar meson (η, η′ and π0) using a data sample of 401 fb-1 collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. No evidence for these decays is found and we set the following upper limits on the branching fractions: B (τ- → e- η) < 9.2 × 10-8, B (τ- → μ- η) < 6.5 × 10-8, B (τ- → e- η′) < 1.6 × 10-7, B (τ- → μ- η′) < 1.3 × 10-7, B (τ- → e- π0) < 8.0 × 10-8 and B (τ- → μ- π0) < 1.2 × 10-7 at the 90% confidence level. These results improve our previously published upper limits by factors from 2.3 to 6.3. © 2007 Elsevier B.V. All rights reserved.