Implications of direct detection experiments in search of mirror dark matter in Galaxy

Abstract: We explore the possibilities of the mirror dark sector and its potential discovery in present and future experiments. Certainly, the mirror dark matters are isomorphic to the standard model lives in the hidden dark sector, and can be investigated in direct detection experiments if kinetic mixing interaction with ordinary matter exists. In this work, we study mirror electrons and mirror nuclei dark matter kinetic mixing interactions with the germanium and xenon targets. We estimate an upper limit on kinetic mixing $\epsilon\leq 10^{-9}$ at 95\% C.L. for mirror electrons in dark plasma at local temperature ranges from 0.1 to 0.3 KeV. This limit manifests strong agreement with the experimental bound from LUX, and appreciably constrain the parameter space for the mirror electrons temperature below 0.3 KeV in the Milky Way halo around spiral galaxies. For mirror nuclei dark matter potentially viable parameter space on kinetic mixing of $10^{-11}$ to $4\cdot 10^{-10}$ can be probed at 95\% C.L for the mirror carbon, mirror oxygen to mirror neon compositions in halos within the mirror dark matter theory. In addition, we examine the dependence of the mirror nuclei dark matter scattering rate on the choice of halo model parameters, mirror nuclear form factors and demonstrate how these choices propagate to the predicted events and kinetic mixing sensitivity limits. We find the choice of halo model parameters affects the predicted sensitivity up to $(15-71)\%$ and parameterizations in nuclear form factor can lead to less than $2\%$ effect on kinetic mixing sensitivity in the allowed parameter space over the mass scale $(11-20)$ GeV. Analyzing all these aspects, we forecast direct detection experiments are highly sensitive and will allow a test of the mirror dark matter theory.