A revisit to scalar dark matter with radiative corrections

Extended Higgs sectors have been studied extensively in context of dark matter phenomenology in tandem with other aspects. In this study, we compute radiative corrections to the dark matter-Higgs portal coupling, which is in fact a common feature of all scalar dark matter models irrespective of the hypercharge of the multiplet from which the dark matter candidate emerges. We select the popular Inert Doublet Model (IDM) as a prototype in order to demonstrate the impact of the next-to-leading order corrections, thereby probing the plausibility of extending the allowed parameter space through quantum effects. This turns out to be true since the loop corrections are sizeable in magnitude even in a scenario where all the inert scalars are decoupled. Given that the tree level portal coupling is a \emph{prima facie} free parameter, the percentage change from loop effects can be large. This modifies the dark matter phenomenology at a quantitative level. It also encourages one to include loop corrections to all other interactions that are deemed relevant in this context.