Search for CP violation in Ξb⁻ → pK⁻K⁻ decays

A search for CP violation in charmless three-body Ξb⁻ → pK⁻K⁻ decays is performed using pp collision data recorded with the LHCb detector, corresponding to integrated luminosities of 1 fb⁻¹ at a center-of-mass energy √s = 7 TeV, 2 fb⁻¹ at √s = 8 TeV and 2 fb⁻¹ at √s = 13 TeV. A good description of the phase-space distribution is obtained with an amplitude model containing contributions from Σ(1385), Λ(1405), Λ(1520), Λ(1670), Σ(1775) and Σ(1915) resonances. The model allows for CP violation effects, which are found to be consistent with zero. The branching fractions of Xi⁻(b) → Σ(1385)K⁻, Ξ⁻(b) → Λ(1405)K⁻, Ξ⁻(b) → Λ(1520)K⁻, Ξ⁻(b) → Λ(1670)K-, Ξ⁻(b) → Σ(1775)K- and Ξ⁻(b) → Σ(1915)K⁻ decays arc also reported. In addition, an upper limit is placed on the product of ratios of Ω⁻(b) and Ξ⁻(b) fragmentation fractions and the Ω⁻(b) → pK⁻K⁻ and Ξ⁻(b) → pK⁻K⁻ branching fractions.