  Searches for $B$ mesons decaying to final states containing a baryon and a
lepton are performed, where the baryon is either $\Lambda_c$ or $\Lambda$ 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 $(3.2-520) \times 10^{-8}$ are set on the branching fractions at the
90% confidence level.

High Energy Physics - Experiment