Absorption of Sub-MeV Fermionic Dark Matter by Electron Targets
  We study a new class of signals where fermionic dark matter is absorbed by
bound electron targets. Fermionic absorption signals in direct detection and
neutrino experiments are sensitive to dark matter with sub-MeV mass, probing a
region of parameter space in which dark matter is otherwise challenging to
detect. We calculate the rate and energy deposition spectrum in xenon-based
detectors, making projections for current and future experiments. We present
two possible models that display fermionic absorption by electrons and study
the detection prospects in light of other constraints.
