Constraints on Low-Mass WIMP Interactions on 19F from PICASSO

TL;DR

The PICASSO experiment set new limits on low-mass WIMP interactions using fluorine detectors, achieving low energy thresholds and no dark matter detection, thus constraining certain WIMP parameter spaces.

Contribution

This study provides the first constraints on low-mass WIMPs using fluorine-based detectors with ultra-low energy thresholds at SNOLAB.

Findings

No dark matter signal was observed.

Excluded spin-dependent WIMP-proton cross sections down to 0.032 pb at 20 GeV/c^2.

Excluded spin-independent cross sections above 1.41x10^-4 pb near 7 GeV/c^2.

Abstract

Recent results from the PICASSO dark matter search experiment at SNOLAB are reported. These results were obtained using a subset of 10 detectors with a total target mass of 0.72 kg of 19F and an exposure of 114 kgd. The low backgrounds in PICASSO allow recoil energy thresholds as low as 1.7 keV to be obtained which results in an increased sensitivity to interactions from Weakly Interacting Massive Particles (WIMPs) with masses below 10 GeV/c^2. No dark matter signal was found. Best exclusion limits in the spin dependent sector were obtained for WIMP masses of 20 GeV/c^2 with a cross section on protons of sigma_p^SD = 0.032 pb (90% C.L.). In the spin independent sector close to the low mass region of 7 GeV/c2 favoured by CoGeNT and DAMA/LIBRA, cross sections larger than sigma_p^SI = 1.41x10^-4 pb (90% C.L.) are excluded.