January 6, 2021
Journal Article

Results on low-mass weakly interacting massive particles from an 11 kg d target exposure of DAMIC at SNOLAB

A. Aguilar-Arevalo
D. Amidei
Daniel Baxter
G. Cancelo
B Cervantes Vergara
Alvaro Chavarria
J.C. D'Olivo
Juan Estrada
Romain Gaior
Y Guardincerri
Eric Hoppe
Todd Hossbach
Ben Kilminster
Steven Lee
Antoine Letessier-Selvon
Ariel Matalon
Pitam Mitra
Cory Overman
A. Piers
Paolo Privitera
Karthik Ramanathan
Joao Da Rocha
Mariangela Settimo
Radomir Smida
Ryan Thomas
Javier Tiffenberg
M Traina
A.L. Virto
Rocio Vilar
F Favela-Perez
Ian Lawson
Y Sarkis

Abstract

We present constraints on the existence of weakly interacting massive particles (WIMPs) from a 11 kg-day target exposure of the DAMIC experiment at the SNOLAB underground laboratory. The observed energy spectrum and spatial distribution of ionization events with electron-equivalent energies $>$200 eV$_{\rm ee}$ in the DAMIC CCDs are consistent with backgrounds from natural radioactivity. An excess of ionization events is observed above the analysis threshold of 50 eV$_{\rm ee}$. While the origin of this low-energy excess requires further investigation, our data exclude spin-independent WIMP-nucleon scattering cross sections $\sigma_{\chi-n}$ as low as $3\times 10^{-41}$ cm$^2$ for WIMPs with masses $m_{\chi}$ from 7 to 10 GeV$c^{-2}$ . These results are the strongest constraints from a silicon target on the existence of WIMPs with $m_{\chi}$$

Revised: January 6, 2021 | Published: December 11, 2020

Citation

Aguilar-Arevalo A., D. Amidei, D. Baxter, G. Cancelo, B.A. Cervantes Vergara, A. Chavarria, and J. D'Olivo, et al. 2020. "Results on low-mass weakly interacting massive particles from an 11 kg d target exposure of DAMIC at SNOLAB." Physical Review Letters 125, no. 24:Article No. 241803. PNNL-SA-155070. doi:10.1103/PhysRevLett.125.241803