Energy Dependence of Direct Detection Cross Section for Asymmetric Mirror Dark Matter

TL;DR

This paper explores how a mirror neutron dark matter model predicts a unique energy-dependent direct detection cross section, potentially explaining experimental signals like DAMA and CoGeNT.

Contribution

It introduces a novel energy dependence in the direct detection cross section for mirror neutron dark matter, highlighting its distinguishable features from conventional WIMPs.

Findings

Cross section increases at low recoil energy for mirror neutron dark matter.

Spin-dependent scattering can significantly contribute to detection rates.

Model can potentially explain DAMA and CoGeNT experimental results.

Abstract

In a recent paper, four of the present authors proposed a class of dark matter models where generalized parity symmetry leads to equality of dark matter abundance with baryon asymmetry of the Universe and predicts dark matter mass to be around 5 GeV. In this note we explore how this model can be tested in direct search experiments. In particular, we point out that if the dark matter happens to be the mirror neutron, the direct detection cross section has the unique feature that it increases at low recoil energy unlike the case of conventional WIMPs. It is also interesting to note that the predicted spin-dependent scattering could make significant contribution to the total direct detection rate, especially for light nucleus. With this scenario, one could explain recent DAMA and CoGeNT results.