Searches for the baryon- and lepton-number violating decays B^{0}→Λ_{c}^{+}l^{-}, B^{-}→Λl^{-}, and B^{-}→Λ[over ̄]l^{-}

Searches for B mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either Λc or Λ and the lepton is a muon or an electron. These decays violate both baryon and lepton number and would be a signature of physics beyond the standard model. No significant signal is observed in any of the decay modes, and upper limits in the range (3.2–520)×10-8 are set on the branching fractions at the 90% confidence level.