Speaker
Description
In this talk, I'll present results from a global analysis of effective Higgs portal dark matter (DM) models in the frequentist and Bayesian statistical frameworks. In particular, we use the GAMBIT software to determine the preferred mass and coupling ranges for vector, Majorana and Dirac fermion DM models. We also assess the relative plausibility of all four (including scalar DM) models using Bayesian model comparison. Our analysis includes up-to-date likelihood functions for the DM relic density, invisible Higgs decays, and direct and indirect searches for weakly-interacting DM, including the latest XENON1T data. We also account for important systematic uncertainties arising from the local density and velocity distribution of DM, nuclear matrix elements relevant for direct detection, and Standard Model masses and couplings. From our global study, we find the parameter regions that can explain all of the DM and give a good fit to the observed data. The case of vector DM requires the most tuning and is therefore slightly disfavoured from a Bayesian point of view, whereas the fermionic DM case requires a strong preference for including a CP-violating phase which allows for a suppression of direct detection limits. Finally, we present $\mathsf{DDCalc~2.0.0}$, a tool for calculating direct detection observables and likelihoods for arbitrary non-relativistic effective operators. All of our results and samples are publicly available via Zenodo.
