Speaker
Description
We consider a new mechanism for enhancing the self-scattering and annihilation cross sections for dark matter with multiple components but without a light mediator. The lighter dark matter component plays a role of the u-channel pole in the elastic co- scattering for dark matter, leading to a large self-scattering cross section and a Som- merfeld enhancement for semi-annihilation processes. Taking the effective theory ap- proach for self-resonant dark matter, we present various combinations of multiple dark matter components with spins and parities that show a u-channel pole in the co- scattering processes. Adopting dark photon and dark Higgs portals for self-resonant dark matter, we impose the relic density condition and indirect detection bounds on semi-annihilation channels with Sommerfeld enhancement and discuss potential signals for direct detection experiments.
