Search for B0 →τ±∓ (ℓ=e, μ) with a hadronic tagging method at Belle SEARCH for B0 →τ±∓ (ℓ=e, μ) with A ... H. ATMACAN et al.

We present a search for the lepton-flavor-violating decays B0→τ±∓, where ℓ=(e,μ), using the full data sample of 772×106 BB¯ pairs recorded by the Belle detector at the KEKB asymmetric-energy e+e- collider. We use events in which one B meson is fully reconstructed in a hadronic decay mode. The τ± lepton is reconstructed indirectly using the momentum of the reconstructed B and that of the ∓ from the signal decay. We find no evidence for B0→τ±∓ decays and set upper limits on their branching fractions at 90% confidence level of B(B0→τ±μ∓)<1.5×10-5 and B(B0→τ±e∓)<1.6×10-5.