2025/03/05 by Chang, C. L., Chang, Y. -Y., Chaplinsky, L. +45 · 13 citations
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Instrumentation and Detectors (physics.ins-det)
paper · doi:10.48550/arxiv.2503.03683
We present results of a search for spin-independent dark matter-nucleon interactions in a 1 cm2 by 1 mm thick (0.233 gram) high-resolution silicon athermal phonon detector operated above ground. For interactions in the substrate, this detector achieves a r.m.s. baseline energy resolution of 361.5 ± 0.4 MeV/c2, the best for any athermal phonon detector to date. With an exposure of 0.233g × 12 hours, we place the most stringent constraints on dark matter masses between 44 and 87 MeV/c2, with the lowest unexplored cross section of 4 × 10-32 cm2 at 87 MeV/c2. We employ a conservative salting technique to reach the lowest dark matter mass ever probed via direct detection experiment. This constraint is enabled by two-channel rejection of low-energy backgrounds that are coupled to individual sensors.