Centers and Institutes
Published March 21, 2022 | Version v1
Journal article Open

Characterization of the background spectrum in DAMIC at SNOLAB

Creators

  • 1. Universidad Nacional Autónoma de México
  • 2. University of Michigan
  • 3. Pacific Northwest National Laboratory
  • 4. University of Chicago
  • 5. Fermi National Accelerator Laboratory
  • 6. University of Washington
  • 7. Sorbonne Université
  • 8. Universität Zürich Physik Institut
  • 9. SNOLAB

Description

We construct the first comprehensive radioactive background model for a dark matter search with charge-coupled devices (CCDs). We leverage the well-characterized depth and energy resolution of the DAMIC at SNOLAB detector and a detailed geant4-based particle-transport simulation to model both bulk and surface backgrounds from natural radioactivity down to $50  eV_{ee}$. We fit to the energy and depth distributions of the observed ionization events to differentiate and constrain possible background sources, for example, bulk $^3H$ from silicon cosmogenic activation and surface < $^{210}Pb$ from radon plate-out. We observe the bulk background rate of the DAMIC at SNOLAB CCDs to be as low as $3.1±0.6  counts kg^{−1} day^{−1} keV_{ee}^{-1}$, making it the most sensitive silicon dark matter detector. Finally, we discuss the properties of a statistically significant excess of events over the background model with energies below $200  eV_{ee}$.

Notes

Due to the large number of authors, only the first 20 and the University of Chicago authors are included on the above author list. Please download the article for the complete list of authors.

Files

PhysRevD.105.062003.pdf

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Additional details

Identifiers

DOI
10.1103/PhysRevD.105.062003
Other
oai:uchicago.tind.io:14208

UChicago Information

Division(s)
Physical Sciences Division
Department(s)
Enrico Fermi Institute
Center(s) or Institute(s)
Kavli Institute for Cosmological Physics