Lepton Flavour Violation and Baryon Number Non-conservation in τ→Λ+h

We have searched for the violation of baryon number B and lepton number L in the (B–L)-conserving modes and as well as the (B–L)-violating modes τ−→Λπ− and τ−→ΛK− using 237 fb−1 of data collected with the BaBar detector at the PEP-II asymmetric-energy e+e− storage rings. We do not observe any signal and we determine preliminary upper limits on the branching fractions , B(τ−→Λπ−)<5.8×10−8, , and B(τ−→ΛK−)<15×10−8 at 90% confidence level.