Hunting for WIMPs: How low should we go?
This event is part of the HET Seminar Series.
Direct detection experiments are rapidly improving their sensitivity to weak scale Dark Matter. A particular interesting (and minimal) possibility is that the Dark matter interacts with ordinary matter via the exchange of weak bosons: the W, Z, and Higgs. Dark matter with substantial coupling to the Higgs boson is already under significant tension from limits on spin-independent scattering. We discuss the power of spin-dependent scattering as a probe of Z-mediated dark matter, both in a simple effective theory, and in the so-called Singlet-Doublet Model, which we argue is a useful benchmark. We also review the case where the cosmology of the WIMP is dominated by co-annihilation processes, focusing on the stop co-annihilation region of the Minimal Supersymmetric Standard Model, and discuss prospects for direct detection in this case.