Revisiting the fermionic dark matter absorption on electron target

A bstract We perform a systematic study of the fermionic DM absorption interactions on electron target in context effective field theory. The is not just sensitive to sub-MeV with efficient energy release, but also gives unique signature clear peak recoil spectrum whose shape largely determined by atomic effects. Fitting Xenon1T and PandaX-II data prefers mass at m χ = 59 keV 105 keV, respectively, while cut-off scale probed up around 1 TeV. overproduction early Universe, invisible decay effect cosmological evolution, visible signal collected astrophysical X(gamma)-ray observations (Insight-HXMT, NuSTAR, HEAO-1, INTEGRAL) are thoroughly explored constrain interactions. With stringent bounds tensor pseudo-scalar operators, other operators particular interest tonne-scale direct detection experiments such as PandaX-4T, XENONnT, LZ.