Observation of the baryonic B-decay B0bar -> Lambda_c^+ antiproton K^- pi^+

TL;DR

This paper reports the first observation of a specific baryonic B-decay involving Lambda_c^+ and measures its branching fraction, along with evidence for a resonant decay mode, using a large data sample from the BABAR experiment.

Contribution

The study provides the first measurement of the branching fraction for B0bar -> Lambda_c^+ antiproton K^- pi^+ and evidence for B0bar -> Sigma_c(2455)^++ antiproton K^- decay, with an upper limit set for another decay mode.

Findings

Measured branching fraction for B0bar -> Lambda_c^+ antiproton K^- pi^+ is (4.33 +/- 0.82_stat +/- 0.33_syst +/- 1.13_Lambda_c^+) x 10^-5.

Evidence found for B0bar -> Sigma_c(2455)^++ antiproton K^- with a branching fraction of (1.11 +/- 0.30_stat +/- 0.09_syst +/- 0.29_Lambda_c^+ ) x 10^-5.

Upper limit of 2.42 x 10^-5 at 90% confidence level for B0bar -> Lambda_c^+ antiproton K^*0.

Abstract

We report the observation of the baryonic B-decay B0bar -> Lambda_c^+ antiproton K^- pi^+, excluding contributions from the decay B0bar -> Lambda_c^+ anti-Lambda K^-. Using a data sample of 467*10^6 BBbar 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_Lambda_c^+)*10^-5. In addition we find evidence for the resonant decay B0bar -> Sigma_c(2455)^++ antiproton K^- and determine its branching fraction to be (1.11 +/- 0.30_stat +/- 0.09_syst +/- 0.29_Lambda_c^+)*10^-5. The errors are statistical, systematic, and due to the uncertainty in the Lambda_c^+ branching fraction. For the resonant decay B0bar -> Lambda_c^+ antiproton K^*0 we obtain an upper limit of 2.42*10^-5 at 90% confidence level.