Observation of the baryonic B decay B ̄0→Λc+Λ̄K-

Abstract

We report the observation of the baryonic B decay B̄0→ Λc+Λ̄K- with a significance larger than 7 standard deviations based on 471×106 BB̄ pairs collected with the BABAR detector at the PEP-II storage ring at SLAC. We measure the branching fraction for the decay B̄0→Λc+Λ̄K- to be (3.8±0.8stat±0.2sys±1.0 Λc+)×10-5. The uncertainties are statistical, systematic, and due to the uncertainty in the Λc+ branching fraction. We find that the Λc+K- invariant-mass distribution shows an enhancement above 3.5GeV/c2. © 2011 American Physical Society.