Improved Spin-Dependent WIMP Limits from a Bubble Chamber

TL;DR

This paper demonstrates the use of a room-temperature bubble chamber with superheated CF$_{3}$I to set new limits on spin-dependent WIMP interactions, showcasing its potential for dark matter detection with high background rejection.

Contribution

First application of a bubble chamber for dark matter search with improved spin-dependent WIMP limits and ultra-low background rejection capabilities.

Findings

Achieved over 250 kg-days exposure with 80% live-time.

Set new limits on spin-dependent WIMP-proton cross section.

Measured photon rejection factor of ~10^{-10}.

Abstract

Bubble Chambers provided the dominant particle detection technology in accelerator experiments for several decades, eventually falling into disuse with the advent of other techniques. We report here on the first period of operation of an ultra-clean, room-temperature bubble chamber containing 1.5 kg of superheated CF$_{3}$I, a target maximally sensitive to spin-dependent and -independent Weakly Interacting Massive Particle (WIMP) couplings. An exposure in excess of 250 kg-days is obtained, with a live-time fraction reaching 80%. This illustrates the ability to employ bubble chambers in a new realm, the search for dark matter particles. Improved limits on the spin-dependent WIMP-proton scattering cross section are extracted from this first period. An extreme intrinsic insensitivity to the backgrounds commonly limiting these experiments (a rejection factor for photon-induced electrons of $\sim10^{-10}$) has been measured in operating conditions leading to the detection of low-energy nuclear recoils such as those expected from WIMPs.