21st Patras Workshop on Axions, WIMPs and WISPs

Where can Dark Matter be hiding?

Not scheduled

20m

University of Western Australia

Oral Presentation

Speaker

Prof. Anthony Williams (University of Adelaide)

Description

The absence of signals in Dark Matter (DM) detection experiments to date motivates scenarios in which the leading detection signals are absent or suppressed. We examine two such cases, using the framework of Effective Field Theory.

i) Pseudoscalar-mediated dark matter: For fermionic DM that is coupled to Standard Model (SM) fermions via pseudoscalar interactions, the tree-level elastic scattering amplitude is extremely small – it is both momentum suppressed and spin-dependent. However, a spin independent scattering amplitude can be induced at loop level and can dominate over the highly suppressed tree level amplitude.

ii) Neutrino portal dark matter: If DM coupled to the SM only via couplings to neutrinos, it would have evaded detection. We ask whether it is possible for DM-neutrino interactions to account for the observed DM relic abundance through standard thermal freeze-out, without violating bounds on neutrinos or charged leptons.