Limits on WIMP cross-sections from the NAIAD experiment at the Boulby Underground Laboratory

TL;DR

The NAIAD experiment at Boulby Underground Laboratory searched for WIMP dark matter interactions using NaI(Tl) detectors from 2000 to 2003, setting new upper limits on WIMP-nucleon cross-sections through pulse shape discrimination.

Contribution

This work provides the first comprehensive analysis of WIMP search data from the NAIAD experiment, establishing the most stringent constraints on spin-dependent WIMP-proton interactions to date.

Findings

No WIMP signal detected in the data.

Set the most stringent limits on WIMP-proton cross-section.

Provided upper bounds on WIMP-nucleon interactions.

Abstract

The NAIAD experiment (NaI Advanced Detector) for WIMP dark matter searches at the Boulby Underground Laboratory (North Yorkshire, UK) ran from 2000 until 2003. A total of 44.9 kg x years of data collected with 2 encapsulated and 4 unencapsulated NaI(Tl) crystals with high light yield were included in the analysis. We present final results of this analysis carried out using pulse shape discrimination. No signal associated with nuclear recoils from WIMP interactions was observed in any run with any crystal. This allowed us to set upper limits on the WIMP-nucleon spin-independent and WIMP-proton spin-dependent cross-sections. The NAIAD experiment has so far imposed the most stringent constraints on the spin-dependent WIMP-proton cross-section.