Direct dark matter searches with the full data set of XMASS-I

TL;DR

This paper reports on comprehensive WIMP dark matter searches using the full dataset of XMASS-I, setting new limits on WIMP-nucleon interactions across a wide mass range with improved analysis techniques.

Contribution

It presents the first full dataset analysis of XMASS-I, including low-threshold triggers and multiple search strategies for WIMP signals and signatures.

Findings

Set a 90% CL limit of 1.4×10⁻⁴⁴ cm² for 60 GeV/c² WIMPs.

Conducted annual modulation analysis with a 90% CL limit of 2.3×10⁻⁴² cm² for 8 GeV/c² WIMPs.

Evaluated Migdal and Bremsstrahlung effects, establishing limits at low WIMP masses.

Abstract

Various WIMP dark matter searches using the full data set of XMASS-I, a single-phase liquid xenon detector, are reported in this paper. Stable XMASS-I data taking accumulated a total live time of 1590.9 days between November 20, 2013 and February 1, 2019 with an analysis threshold of ${\rm 1.0\,keV_{ee}}$. In the latter half of data taking a lower analysis threshold of ${\rm 0.5\,keV_{ee}}$ was also available through a new low threshold trigger. Searching for a WIMP signal in the detector's 97~kg fiducial volume yielded a limit on the WIMP-nucleon scattering cross section of ${\rm 1.4\times 10^{-44}\, cm^{2}}$ for a ${\rm 60\,GeV/c^{2}}$ WIMP at the 90$\%$ confidence level. We also searched for WIMP induced annual modulation signatures in the detector's whole target volume, containing 832~kg of liquid xenon. For nuclear recoils of a ${\rm 8\,GeV/c^{2}}$ WIMP this analysis yielded a 90\% CL cross section limit of ${\rm 2.3\times 10^{-42}\, cm^{2}}$. At a WIMP mass of ${\rm 0.5\, GeV/c^{2}}$ the Migdal effect and Bremsstrahlung signatures were evaluated and lead to 90\% CL cross section limits of ${\rm 1.4\times 10^{-35}\, cm^{2}}$ and ${\rm 1.1\times 10^{-33}\, cm^{2}}$ respectively.