EFT Approach of Inelastic Dark Matter for Xenon Electron Recoil Detection

Understand

Measuring dark matter (DM) signals via electron recoil provides an important means for direct detection of light DM particles.

• The recent XENON1T anomaly with electron recoil energy around $\,E_R^{}\!=\!(2-3)$keV can be naturally explained by DM inelastic scattering which injects energy to the recoiled electrons and gives a narrow peak structure in the recoil spectrum.
• We present an effective field theory (EFT) approach to exothermic inelastic DM signals for the Xenon electron recoil detection.
• For relatively heavy mediator, we fairly formulate the DM-lepton interactions by effective contact operators with two DM fields $(X,\,X')$ and two leptons.