Simplified Dark Matter Models with Charged Mediators: Prospects for Direct Detection

Understand

We consider direct detection prospects for a class of simplified models of fermionic dark matter (DM) coupled to left and right-handed Standard Model fermions via two charged scalar mediators with arbitrary mixing angle $\alpha$.

• DM interactions with the nucleus are mediated by higher electromagnetic moments, which, for Majorana DM, is the anapole moment.
• After giving a full analytic calculation of the anapole moment, including its $\alpha$ dependence, and matching with limits in the literature, we compute the DM-nucleon scattering cross-section and show the LUX and future LZ constraints on the parameter space of these models.
• We then compare these results with constraints coming from $Fermi$-LAT continuum and line searches.