UC Berkeley

We present a search for the lepton flavor violating decay modes B ±→h ±τ l (h=K, π; l=e, μ) using the BABAR data sample, which corresponds to 472×106 BB̄ pairs. The search uses events where one B meson is fully reconstructed in one of several hadronic final states. Using the momenta of the reconstructed B, h, and l candidates, we are able to fully determine the τ four-momentum. The resulting τ candidate mass is our main discriminant against combinatorial background. We see no evidence for B ±→h ±τ l decays and set a 90% confidence level upper limit on each branching fraction at the level of a few times 10 -5. © 2012 American Physical Society.