Electroweak corrections to the direct detection cross section of inert Higgs dark matter

Abstract

The inert higgs model is a minimal extension of the Standard Model that features a viable dark matter candidate, the so-called inert higgs ($H^0$). In this paper, we compute and analyze the dominant electroweak corrections to the direct detection cross section of dark matter within this model. These corrections arise from one-loop diagrams mediated by gauge bosons that, contrary to the tree-level result, do not depend on the unknown scalar coupling $\lambda$. We study in detail these contributions and show that they can modify in a significant way the prediction of the spin-independent direct detection cross section. In both viable regimes of the model, $\mh<M_W$ and $\mh\gtrsim 500 \gev$, we find regions where the cross section at one-loop is much larger than at tree-level. We also demonstrate that, over the entire viable parameter space of this model, these new contributions bring the spin-independent cross section within the reach of future direct detection experiments.