Observation of the baryonic B-decay ¯¯¯B0→Λ+c¯pK−π+

Abstract

We report the observation of the baryonic B -decay ¯¯¯ B 0 → Λ + c ¯ p K − π + , excluding contributions from the decay ¯¯¯ B 0 → Λ + c ¯¯¯ Λ K − . Using a data sample of 467 × 10 6 B ¯¯¯ B pairs collected with the BABAR detector at the PEP-II storage ring at SLAC, the measured branching fraction is ( 4.33 ± 0.82 stat ± 0.33 syst ± 1.13 Λ + c ) × 10 − 5 . In addition we find evidence for the resonant decay ¯¯¯ B 0 → Σ c ( 2455 ) ++ ¯ p K − and determine its branching fraction to be ( 1.11 ± 0.30 stat ± 0.09 syst ± 0.29 Λ + c ) × 10 − 5 . The errors are statistical, systematic, and due to the uncertainty in the Λ + c branching fraction. For the resonant decay ¯¯¯ B 0 → Λ + c ¯ p ¯¯¯¯ K * 0 we obtain an upper limit of 2.42 × 10 − 5 at 90% confidence level.