arXiv · 1908.10881
On the relation between Migdal effect and dark matter-electron scattering in isolated atoms and semiconductors
Abstract
A key strategy for the direct detection of sub-GeV dark matter is to search for small ionization signals. These can arise from dark matter-electron scattering or when the dark matter-nucleus scattering process is accompanied by a "Migdal" electron. We show that the theoretical descriptions of both processes are closely related, which allows for a principal mapping between dark matter-electron and dark matter-nucleus scattering rates once the dark matter interactions with matter are specified. We explore this parametric relationship for noble-liquid targets and, for the first time, provide an estimate of the "Migdal" ionization rate in semiconductors that is based on evaluating a crystal form factor that accounts for the semiconductor band structure. We also present new dark-matter-nucleus scattering limits down to dark matter masses of 500 keV using published data from XENON10, XENON100, and a SENSEI prototype Skipper-CCD. For a dark photon mediator, the dark matter-electron scattering rates dominate over the Migdal rates for dark matter masses below 100 MeV. We also provide projections for proposed experiments with xenon and silicon targets.
Explore related subjects
Keep this discovery
Explore connections, maps & timelines
Rouven Essig, Josef Pradler, Mukul Sholapurkar, Tien-Tien Yu. 2020-02-03. On the relation between Migdal effect and dark matter-electron scattering in isolated atoms and semiconductors. https://doi.org/10.1103/physrevlett.124.021801
Cite the original work for its findings. Save a collection to share your selection of sources.