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 Ξb−→Σ(1385)K−, Ξb−→Λ(1405)K−, Ξb−→Λ(1520)K−, Ξb−→Λ(1670)K−, Ξb−→Σ(1775)K− and Ξb−→Σ(1915)K− decays are also reported. In addition, an upper limit is placed on the product of ratios of Ωb− and Ξb− fragmentation fractions and the Ωb−→pK−K− and Ξb−→pK−K− branching fractions.7 MoreReceived 3 May 2021Accepted 11 August 2021DOI:https://doi.org/10.1103/PhysRevD.104.052010Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.© 2021 CERN, for the LHCb CollaborationPhysics Subject Headings (PhySH)Physical SystemsBaryonsPropertiesCP violationParticles & Fields