Limits on Spin-Dependent WIMP-Nucleon Cross Section Obtained from the Complete LUX Exposure

We present experimental constraints on the spin-dependent WIMP-nucleon elastic cross sections from the total 129. 5 kg yr exposure acquired by the Large Underground Xenon experiment (LUX), operating at the Sanford Underground Research Facility in Lead, South Dakota (USA). A profile likelihood ratio analysis allows 90% C. L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σ₍=1. 6×10^-41 cm^2 (σ₏=5×10^-40 cm^2) at 35 GeV c^-2, almost a sixfold improvement over the previous LUX spin-dependent results. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.