|DATE||October 14 (Thu), 2021|
|TITLE||Self-Resonant Dark Matter|
We present a novel mechanism for Sommerfeld enhancement for dark matter interactions without the need for light mediators. Considering a model for two-component scalar dark matter with a triple coupling, we find that there appears an u-channel resonance in dark matter elastic scattering. From the sum of the corresponding ladder diagrams, we obtain a Bethe-Salpeter equation with a delay term and identify the Sommerfeld factor for two-component dark matter from the effective Yukawa potential for the first time. We discuss the implications of our results for enhancing dark matter self-scattering and annihilation.