Models for Self-resonant Dark Matter

TL;DR

This paper introduces a new mechanism for enhancing dark matter self-scattering and semi-annihilation without a light mediator, using multiple components and effective theory, with implications for detection experiments.

Contribution

It proposes a novel self-resonant dark matter model with multiple components, demonstrating enhanced cross sections via a $u$-channel pole and Sommerfeld effect, and explores detection prospects.

Findings

Large self-scattering cross sections achieved without light mediators.

Sommerfeld enhancement significantly boosts semi-annihilation signals.

Model consistent with relic density and indirect detection constraints.

Abstract

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 Sommerfeld enhancement for semi-annihilation processes. Taking the effective theory approach for self-resonant dark matter, we present various combinations of multiple dark matter components with spins and parities, showing 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 as well as indirect detection bounds on semi-annihilation channels with a Sommerfeld enhancement and discuss potential signals for direct detection experiments.