Observation of B+->Lambda_c+Lambda_c-K+ and B0->Lambda_c+Lambda_c^-K0 decays

TL;DR

This paper reports the first measurements of specific doubly charmed baryonic B decays, observing two decay modes with significant statistical confidence and providing their branching fractions based on Belle detector data.

Contribution

First measurement of B->Lambda_c+Lambda_c-K decays, including observation and branching fraction determination with detailed uncertainty analysis.

Findings

B+->Lambda_c+Lambda_c-K+ decay observed with 15.4sigma significance.

B0->Lambda_c+Lambda_c-K0 decay observed with 6.6sigma significance.

Branching fractions measured as approximately 6.5x10^{-4} and 7.9x10^{-4}.

Abstract

We report first measurements of the doubly charmed baryonic B decays B->Lambda_c+Lambda_c-K. The B+->Lambda_c+Lambda_c-K+ decay is observed with a branching fraction of (6.5+1.0-0.9+-1.1+-3.4)x10^{-4} and a statistical significance of 15.4sigma. The B0->Lambda_c+Lambda_c-K0 decay is observed with a branching fraction of (7.9+2.9-2.3+-1.2+-4.2)x10^{-4} and a statistical significance of 6.6sigma. The branching fraction errors are statistical, systematic, and the error resulting from the uncertainty of Lambda_c+->pK-pi+ decay branching fraction. The analysis is based on 357fb-1 of data accumulated at the Y(4S) resonance with the Belle detector at the KEKB asymmetric e+e- collider.