Asymmetric dark matter: residual annihilations and self-interactions

TL;DR

This paper explores asymmetric dark matter models with light mediators, showing that detectable residual annihilations are possible even with large asymmetries, and identifies viable self-interacting dark matter scenarios constrained by multiple observational searches.

Contribution

It demonstrates that residual annihilations can occur in asymmetric dark matter with light mediators and derives observational bounds, expanding the understanding of viable dark matter models.

Findings

Detectable residual annihilations occur even with large asymmetries.

Bounds from CMB, gamma-ray, neutrino, and antiproton searches constrain these models.

Direct detection offers a test for the viable self-interacting dark matter scenarios.

Abstract

Dark matter (DM) coupled to light mediators has been invoked to resolve the putative discrepancies between collisionless cold DM and galactic structure observations. However, $\gamma$-ray searches and the CMB strongly constrain such scenarios. To ease the tension, we consider asymmetric DM. We show that, contrary to the common lore, detectable annihilations occur even for large asymmetries, and derive bounds from the CMB, $\gamma$-ray, neutrino and antiproton searches. We then identify the viable space for self-interacting DM. Direct detection does not exclude this scenario, but provides a way to test it.