Results on the Spin-Dependent Scattering of Weakly Interacting Massive Particles on Nucleons from the Run 3 Data of the LUX Experiment

TL;DR

This paper reports the first experimental constraints on spin-dependent WIMP-nucleon cross sections from LUX data, setting the most sensitive limits to date on WIMP-neutron interactions at 33 GeV/c².

Contribution

It provides the first experimental limits on spin-dependent WIMP-nucleon interactions using LUX data, improving the sensitivity of previous constraints.

Findings

90% CL upper limit on WIMP-neutron cross section: 9.4×10⁻⁴¹ cm²

90% CL upper limit on WIMP-proton cross section: 2.9×10⁻³⁹ cm²

Most sensitive constraint on WIMP-neutron interactions to date

Abstract

We present the first experimental constraints on the spin-dependent WIMP-nucleon elastic cross sections from LUX data acquired in 2013. LUX is a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota), which is designed to observe the recoil signature of galactic WIMPs scattering from xenon nuclei. A profile likelihood ratio analysis of $1.4~\times~10^{4}~\text{kg}\cdot~\text{days}$ of fiducial exposure allows 90% CL upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of $\sigma_n~=~9.4~\times~10^{-41}~\text{cm}^2$ ($\sigma_p~=~2.9~\times~10^{-39}~\text{cm}^2$) at 33 GeV/c$^2$. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.