The low-energy spectrum in DAMIC at SNOLAB

TL;DR

The DAMIC experiment uses advanced CCD detectors to search for low-mass dark matter particles, reporting an unexplained excess of low-energy events and ongoing efforts to improve measurement precision with new detector technology.

Contribution

This paper presents the first dark matter search results from DAMIC at SNOLAB, including an analysis of low-energy events and plans for enhanced measurements with skipper CCDs.

Findings

Observed an excess of events below 200 eV$_{ m ee}$

Detailed spectral analysis of the collected data

Upcoming deployment of skipper CCDs for improved measurements

Abstract

The DAMIC experiment employs large-area, thick charge-coupled devices (CCDs) to search for the interactions of low-mass dark matter particles in the galactic halo with silicon atoms in the CCD target. From 2017 to 2019, DAMIC collected data with a seven-CCD array (40-gram target) installed in the SNOLAB underground laboratory. We report dark-matter search results, including a conspicuous excess of events above the background model below 200 eV$_{\rm ee}$, whose origin remains unknown. We present details of the published spectral analysis, and update on the deployment of skipper CCDs to perform a more precise measurement by early 2023.