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

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, M-H0 < M-W and M-H0 greater than or similar to 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. DOI: 10.1103/PhysRevD.87.075025