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

A search for $CP$ violation in charmless three-body $\\Xi_b^- \\to p K^- K^-$ decays is performed using $pp$ collision data recorded with the LHCb detector, corresponding to integrated luminosities of $1\\,\\text{fb}^{-1}$ at a centre-of-mass energy $\\sqrt{s} = 7\\,\\text{TeV}$, $2\\,\\text{fb}^{-1}$ at $\\sqrt{s} = 8\\,\\text{TeV}$ and $2\\,\\text{fb}^{-1}$ at $\\sqrt{s} = 13\\,\\text{TeV}$. A good description of the phase-space distribution is obtained with an amplitude model containing contributions from $\\Sigma(1385)$, $\\Lambda(1405)$, $\\Lambda(1520)$, $\\Lambda(1670)$, $\\Sigma(1775)$ and $\\Sigma(1915)$ resonances. The model allows for $CP$-violation effects, which are found to be consistent with zero. The branching fractions of $\\Xi_b^- \\to \\Sigma(1385) K^-$, $\\Xi_b^- \\to \\Lambda(1405) K^-$, $\\Xi_b^- \\to \\Lambda(1520) K^-$, $\\Xi_b^- \\to \\Lambda(1670) K^-$, $\\Xi_b^- \\to \\Sigma(1775) K^-$ and $\\Xi_b^- \\to \\Sigma(1915) K^-$ decays are also reported. In addition, an upper limit is placed on the product of ratios of $\\Omega_b^-$ and $\\Xi_b^-$ fragmentation fractions and the $\\Omega_b^- \\to p K^- K^-$ and $\\Xi_b^- \\to p K^- K^-$ branching fractions.