Observation of the baryonic B decay B0bar --> Lambda_c^+ anti-Lambda K-

TL;DR

This paper reports the first observation of the baryonic decay B0bar --> Lambda_c^+ anti-Lambda K- with a high significance, measuring its branching fraction and analyzing the invariant mass distribution of the decay products.

Contribution

The study provides the first experimental evidence of the B0bar --> Lambda_c^+ anti-Lambda K- decay and measures its branching fraction, contributing new data to baryonic B decay research.

Findings

Decay observed with >7 sigma significance

Branching fraction measured as (3.8 ± 0.8 ± 0.2 ± 1.0) x 10^{-5}

Invariant mass distribution shows enhancement above 3.5 GeV/c^2

Abstract

We report the observation of the baryonic B decay B0bar --> Lambda_c^+ anti-Lambda K- with a significance larger than 7 standard deviations based on 471x10^6$ BBbar pairs collected with the BABAR detector at the PEP-II storage ring at SLAC. We measure the branching fraction for the decay B0bar --> Lambda_c^+ anti-Lambda K- to be (3.8 \pm 0.8_{stat} \pm 0.2_{sys} \pm 1.0_{Lambda_c^+})x10^{-5}. The uncertainties are statistical, systematic, and due to the uncertainty in the Lambda_c^+ branching fraction. We find that the Lambda_c^+ K^- invariant mass distribution shows an enhancement above 3.5 GeV/c^2.