Collective excitations and low-energy ionization signatures of relativistic particles in silicon detectors

Abstract

Solid-state detectors with a low energy threshold have several applications, including searches of non-relativistic halo dark-matter particles with sub-GeV masses. When searching for relativistic, beyond-the-Standard-Model particles with enhanced cross sections for small energy transfers, a small detector with a low energy threshold may have better sensitivity than a larger detector with a higher energy threshold. In this paper, we calculate the low-energy ionization spectrum from high-velocity particles scattering in a dielectric material. We consider the full material response including the excitation of bulk plasmons. We generalize the energy-loss function to relativistic kinematics, and benchmark existing tools used for halo dark-matter scattering against electron energy-loss spectroscopy data. Compared to calculations commonly used in the literature, such as the Photo-Absorption-Ionization model or the free-electron model, including collective effects shifts the recoil ionization spectrum towards higher energies, typically peaking around 4--6 electron-hole pairs. We apply our results to the three benchmark examples: millicharged particles produced in a beam, neutrinos with a magnetic dipole moment produced in a reactor, and upscattered dark-matter particles. Our results show that the proper inclusion of collective effects typically enhances a detector's sensitivity to these particles, since detector backgrounds, such as dark counts, peak at lower energies.

25 pages, 9 figures including appendices and references. Error corrected in Eqs. (1, 2, 3). Numerical shift in cross section but qualitative results unchanged

References in corpus (33)

• SENSEI: Direct-Detection Results on sub-GeV Dark Matter from a New Skipper-CCD
• Single-electron and single-photon sensitivity with a silicon Skipper CCD
• SENSEI: Direct-Detection Constraints on Sub-GeV Dark Matter from a Shallow Underground Run Using a Prototype Skipper-CCD
• First germanium-based constraints on sub-MeV Dark Matter with the EDELWEISS experiment
• Constraints on low-mass, relic dark matter candidates from a surface-operated SuperCDMS single-charge sensitive detector
• Search for low-mass WIMPs in a 0.6 kg day exposure of the DAMIC experiment at SNOLAB
• Search for Light Dark Matter-Electron Scatterings in the PandaX-II Experiment
• First Constraints from DAMIC-M on Sub-GeV Dark-Matter Particles Interacting with Electrons
• Emission of Single and Few Electrons in XENON1T and Limits on Light Dark Matter
• Determining Dark Matter-Electron Scattering Rates from the Dielectric Function
• The Migdal effect in semiconductors
• DarkELF: A python package for dark matter scattering in dielectric targets
• Ionization Yield in Silicon for eV-Scale Electron-Recoil Processes
• A Dark Matter Interpretation of Excesses in Multiple Direct Detection Experiments
• Elastic and Inelastic Scattering of Cosmic-Rays on Sub-GeV Dark Matter
• Scalar Direct Detection: In-Medium Effects
• The physics potential of a reactor neutrino experiment with Skipper CCDs: Measuring the weak mixing angle
• Solar reflection of light dark matter with heavy mediators
• Probing dark photons with plasma haloscopes
• Present and future status of light dark matter models from cosmic-ray electron upscattering
• Snowmass2021 Cosmic Frontier: The landscape of low-threshold dark matter direct detection in the next decade
• Millicharged Cosmic Rays and Low Recoil Detectors
• Constraining light dark matter upscattered by ultrahigh-energy cosmic rays
• EXCEED-DM: Extended Calculation of Electronic Excitations for Direct Detection of Dark Matter
• Directional detection of dark matter with anisotropic response functions
• Accelerating Earth-Bound Dark Matter
• The physics potential of a reactor neutrino experiment with Skipper-CCDs: Searching for new physics with light mediators
• Experimental Limits on Solar Reflected Dark Matter with a New Approach on Accelerated-Dark-Matter-Electron Analysis in Semiconductors
• DM-electron scattering in materials: sum rules and heterostructures
• Linear response theory for light dark matter-electron scattering in materials
• Searching for millicharged particles with 1 kg of Skipper-CCDs using the NuMI beam at Fermilab
• Beyond-DFT $\text{ab initio}$ Calculations for Accurate Prediction of Sub-GeV Dark Matter Experimental Reach
• Solar reflection of dark matter with dark-photon mediators

Cited by in corpus (3)

• SENSEI at SNOLAB: Single-Electron Event Rate and Implications for Dark Matter
• Underground Production of Electromagnetic Dark States by MeV-scale Electron Beams and Detection with CCDs
• Nuclear and electron scattering by neutrinos and dark matter in condensed systems