Speaker
Description
Dark matter direct searches place very stringent constraints on the possible DM candidates proposed in extensions of the Standard Model. There are however models where these constraints are avoided. One of the simplest and most striking examples comes from a straightforward Higgs portal pseudoscalar DM model featured with a softly broken U(1) symmetry. In this model the tree-level DM-nucleon scattering cross section vanishes in the limit of zero momentum-transfer. It has also been argued that the leading-order DM-nucleon cross section appears at the one-loop level. We have calculated the exact cross section at the one-loop level, which is several orders of magnitude larger than the tree-level one. We will also present results for a simple model with a vector dark
matter particle.
