Observation of the Λ0b→Λ+cK+K−π− decay
The Λ0b→Λ+cK+K−π−Λb0→Λc+K+K−π− decay is observed for the first time using a data sample of proton-proton collisions at centre-of-mass energies of s√=7s=7 and 8 TeVTeV collected by the LHCbLHCb detector, corresponding to an integrated luminosity of 3fb−13fb−1. The ratio of branching fractions between the Λ0b→Λ+cK+K−π−Λb0→Λc+K+K−π− and the Λ0b→Λ+cD−sΛb0→Λc+Ds− decays is measured to be
where the first uncertainty is statistical, the second systematic and the third is due to the knowledge of the D−s→K+K−π−Ds−→K+K−π− branching fraction. No structure on the invariant mass distribution of the Λ+cK+Λc+K+ system is found, consistent with no open-charm pentaquark signature.