The Phonon Background from Gamma Rays in Sub-GeV Dark Matter Detectors

Abstract

High-energy photons with $\mathcal{O}$(MeV) energies from radioactive contaminants can scatter in a solid-state target material and constitute an important low-energy background for sub-GeV dark matter direct-detection searches. This background is most noticeable for energy deposits in the $1-100$ meV range due to the partially coherent scattering enhancement in the forward scattering direction. We comprehensively quantify the resulting single- and multi-phonon background in Si, Ge, GaAs, SiC, and Al${}_2$O${}_3$ target materials, which are representative of target materials of interest in low-mass dark matter searches. We use a realistic representation of the high-energy photon background, and contrast the expected background phonon spectrum with the expected dark matter signal phonon spectrum. An active veto is needed to suppress this background sufficiently in order to allow for the detection of a dark matter signal, even in well-shielded environments. For comparison we also show the expected single- and multi-phonon event rates from coherent neutrino-nucleus scattering due to solar neutrinos, and find that they are sub-dominant to the photon-induced phonon background.

arXiv comment14 pages, 6 figures, 1 table; v2: Added Appendix D with derivation of solar neutrino background. Added solar neutrino background to Fig.3. Added acoustic corrections to light-dark-photon signal displayed in Fig.3 with clarifications in main text. Fixed typos in Fig.3 legend, eq.19, and A25

References in corpus (52)

• New solar opacities, abundances, helioseismology, and neutrino fluxes
• Direct Detection of Sub-GeV Dark Matter
• A search for light dark matter in XENON10 data
• Light Dark Matter Search with Ionization Signals in XENON1T
• First results from the CRESST-III low-mass dark matter program
• First Direct Detection Limits on sub-GeV Dark Matter from XENON10
• SENSEI: Direct-Detection Results on sub-GeV Dark Matter from a New Skipper-CCD
• New Constraints and Prospects for sub-GeV Dark Matter Scattering off Electrons in Xenon
• First Dark Matter Constraints from a SuperCDMS Single-Charge Sensitive Detector
• Projected Sensitivity of the SuperCDMS SNOLAB experiment
• Single-electron and single-photon sensitivity with a silicon Skipper CCD
• Superconducting Detectors for Super Light Dark Matter
• Constraints on Sub-GeV Dark Matter-Electron Scattering from the DarkSide-50 Experiment
• Constraints on Light Dark Matter Particles Interacting with Electrons from DAMIC at SNOLAB
• Detection of sub-MeV Dark Matter with Three-Dimensional Dirac Materials
• First germanium-based constraints on sub-MeV Dark Matter with the EDELWEISS experiment
• Detecting Superlight Dark Matter with Fermi-Degenerate Materials
• Detection of Light Dark Matter With Optical Phonons in Polar Materials
• Semiconductor Probes of Light Dark Matter
• Detecting Dark Matter with Superconducting Nanowires
• Constraints on low-mass, relic dark matter candidates from a surface-operated SuperCDMS single-charge sensitive detector
• Directional Detection of Dark Matter with Two-Dimensional Targets
• Results on MeV-scale dark matter from a gram-scale cryogenic calorimeter operated above ground
• On the Detectability of Light Dark Matter with Superfluid Helium
• New Constraints on Dark Photon Dark Matter with Superconducting Nanowire Detectors in an Optical Haloscope
• Direct Detection of sub-GeV Dark Matter with Scintillating Targets
• Directional Detection of Light Dark Matter with Polar Materials
• Modulation Effects in Dark Matter-Electron Scattering Experiments
• Diamond Detectors for Direct Detection of Sub-GeV Dark Matter
• Light Dark Matter Search with a High-Resolution Athermal Phonon Detector Operated Above Ground
• A low-mass dark matter search using ionization signals in XENON100
• Multi-Channel Direct Detection of Light Dark Matter: Target Comparison
• Multi-Channel Direct Detection of Light Dark Matter: Theoretical Framework
• Solar Neutrinos as a Signal and Background in Direct-Detection Experiments Searching for Sub-GeV Dark Matter With Electron Recoils
• Determining Dark Matter-Electron Scattering Rates from the Dielectric Function
• SiC Detectors for Sub-GeV Dark Matter
• Performance of the EDELWEISS-III experiment for direct dark matter searches
• DarkELF: A python package for dark matter scattering in dielectric targets
• Sub-GeV Dark Matter Detection with Electron Recoils in Carbon Nanotubes
• Dark matter-electron scattering in dielectrics
• Searches for electron interactions induced by new physics in the EDELWEISS-III germanium bolometers
• Dark Matter-Electron Scattering from Aromatic Organic Targets
• Investigation of background electron emission in the LUX detector
• Extended Calculation of Dark Matter-Electron Scattering in Crystal Targets
• Effective Field Theory of Dark Matter Direct Detection With Collective Excitations
• Thermal detection of single e-h pairs in a biased silicon crystal detector
• Sources of Low-Energy Events in Low-Threshold Dark Matter and Neutrino Detectors
• Direct Detection of Spin-(In)dependent Nuclear Scattering of Sub-GeV Dark Matter Using Molecular Excitations
• Multiphonon excitations from dark matter scattering in crystals
• Sub-MeV Dark Matter and the Goldstone Modes of Superfluid Helium
• Nuclear-recoil energy scale in CDMS II silicon dark-matter detectors
• The coherent photon scattering background in sub-GeV/$c^2$ direct dark matter searches

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