# Limits on spin-dependent WIMP-nucleon cross section obtained from the complete LUX exposure

## TL;DR

This paper reports new experimental constraints on spin-dependent WIMP-nucleon interactions from the complete LUX exposure, significantly improving previous limits and providing the most sensitive WIMP-neutron constraint to date.

## Contribution

The study provides the most sensitive constraints on spin-dependent WIMP-nucleon cross sections using the full LUX data set, employing a profile likelihood analysis.

## Key findings

- 90% CL upper limit on WIMP-neutron cross section: 1.6×10⁻⁴¹ cm²
- 90% CL upper limit on WIMP-proton cross section: 5×10⁻⁴⁰ cm²
- Almost sixfold improvement over previous LUX results

## Abstract

We present experimental constraints on the spin-dependent WIMP-nucleon elastic cross sections from the total 129.5 kg-year 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% CL upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of $\sigma_n$ = 1.6$\times 10^{-41}$ cm$^{2}$ ($\sigma_p$ = 5$\times 10^{-40}$ 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.