Observation of the Λb0 → Λc+ K+ K− π− Decay

The 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 = 7 and 8 TeV collected by the LHCb detector, corresponding to an integrated luminosity of 3 fb^−1. The ratio of branching fractions between the Λb0 → Λc+ K+ K− π− and the Λb0 → Λc+ Ds− decays is measured to be B(Λb0 → Λc+ K+ K− π−)/B(Λb0 → Λc+ Ds−) = (9.26 ± 0.29 ± 0.46 ± 0.26) × 10^−2, where the first uncertainty is statistical, the second systematic and the third is due to the knowledge of the Ds− → K+ K− π− branching fraction. No structure on the invariant mass distribution of the Λc+ K+ system is found, consistent with no open-charm pentaquark signature.