Search for neutrinoless decays τ→ℓhh and τ→ℓV0

We have searched for neutrinoless τ lepton decays into ℓhh or ℓV0, where ℓ stands for an electron or muon, h for a charged light hadron, π or K, and V0 for a neutral vector meson, ρ0, K∗(892)0 and ϕ, using a 158 fb−1 data sample collected with the Belle detector at the KEKB e+e− collider. Since the number of events observed are consistent with the expected background, we set upper limits on the branching fractions in the range of (1.6–8.0)×10−7 for various decay modes at the 90% confidence level.