Study of b-hadron decays to Λ+ c h −h ′− final states

Decays of Ξ − b and Ω − b baryons to Λ + c h −h ′− fnal states, with h −h ′− being π −π −, K−π − and K−K− meson pairs, are searched for using data collected with the LHCb detector. The data sample studied corresponds to an integrated luminosity of 8.7 fb−1 of pp collisions collected at centre-of-mass energies √ s = 7, 8 and 13 TeV. The products of the relative branching fractions and fragmentation fractions for each signal mode, relative to the B− → Λ + c pπ− mode, are measured, with Ξ − b → Λ + c K−π −, Ξ − b → Λ + c K−K− and Ω − b → Λ + c K−K− decays being observed at over 5 σ signifcance. The Ξ − b → Λ + c K−π − mode is also used to measure the Ξ − b production asymmetry, which is found to be consistent with zero. In addition, the B− → Λ + c pK− decay is observed for the frst time, and its branching fraction is measured relative to that of the B− → Λ + c pπ− mode.