Observation of ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\Lambda}}_{c}^{+}{\ensuremath{\Lambda}}_{c}^{\ensuremath{-}}{K}^{+}$ and ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\Lambda}}_{c}^{+}{\ensuremath{\Lambda}}_{c}^{\ensuremath{-}}{K}^{0}$ Decays

Observation of $B^{+} \to Λ_{c}^{+} Λ_{c}^{-} K^{+}$ and $B^{0} \to Λ_{c}^{+} Λ_{c}^{-} K^{0}$ Decays

N. Gabyshev et al. (Belle Collaboration)

Phys. Rev. Lett. 97, 202003 – Published 17 November 2006

Abstract

We report the first measurements of the doubly charmed baryonic $B$ decays $B \to Λ_{c}^{+} Λ_{c}^{-} K$ . The $B^{+} \to Λ_{c}^{+} Λ_{c}^{-} K^{+}$ decay is observed with a branching fraction of $({6.5}_{- 0.9}^{+ 1.0} \pm 1.1 \pm 3.4) \times 10^{- 4}$ and a statistical significance of $15.4 σ$ . The $B^{0} \to Λ_{c}^{+} Λ_{c}^{-} K^{0}$ decay is observed with a branching fraction of $({7.9}_{- 2.3}^{+ 2.9} \pm 1.2 \pm 4.1) \times 10^{- 4}$ and a statistical significance of $6.6 σ$ . The branching fraction errors are statistical, systematic, and the error resulting from the uncertainty of the $Λ_{c}^{+} \to p K^{-} π^{+}$ decay branching fraction. The analysis is based on $357 {fb}^{- 1}$ of data accumulated at the $Υ (4 S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+} e^{-}$ collider.