DAMA annual modulation is not due to electron recoils from Plasma/Mirror Dark Matter with Kinetic Mixing

Abstract

If dark matter is composed of new fundamental particles, Earth's orbital motion around the Sun may induce an annual modulation in the rate at which these particles interact in a terrestrial detector. The DAMA collaboration has identified at a 12$\sigma$ confidence level such an annual modulation in their event rate. One previously proposed explanation is `plasma dark matter' (e.g. mirror dark matter) which would have electron recoils in the detector from interactions via kinetic mixing. We perform a chi-squared goodness of fit test of this plasma dark matter model to DAMA/LIBRA modulation amplitude which rejects the hypothesis of plasma dark matter as an explanation of this data at greater than 7$\sigma$.