Observation of the Decay Ξb-→p K-K-

Abstract

Decays of the Ξb- and Ωb- baryons to the charmless final states p h-h'- , where h(') denotes a kaon or pion, are searched for with the LHCb detector. The analysis is based on a sample of proton-proton collision data collected at center-of-mass energies √{s }=7 and 8 TeV, corresponding to an integrated luminosity of 3 fb-1 . The decay Ξb- →p K-K- is observed with a significance of 8.7 standard deviations, and evidence at the level of 3.4 standard deviations is found for the Ξb- →p K-π- decay. Results are reported, relative to the B- →K+K-K- normalization channel, for the products of branching fractions and b -hadron production fractions. The branching fractions of Ξb- →p K-π- and Ξb- →p π-π- relative to Ξb- →p K-K- decays are also measured.