Sommerfeld Enhancements for Asymmetric Dark Matter

TL;DR

This paper investigates how Sommerfeld enhancement, caused by long-range interactions, affects the relic density of asymmetric Dark Matter with a massive mediator, including the impact of kinetic decoupling and observational constraints.

Contribution

It extends previous analyses by considering a massive mediator and explores the combined effects of Sommerfeld enhancement and kinetic decoupling on Dark Matter relic density.

Findings

Sommerfeld enhancement significantly alters relic density calculations.

Kinetic decoupling impacts the effectiveness of annihilation cross sections.

Constraints on model parameters are derived from observational Dark Matter data.

Abstract

We extend the analysis of asymmetric Dark Matter relic density with Sommerfeld enhancement to the case where the mediator is massive. In asymmetric Dark Matter models, the asymmetric Dark Matter is assumed to couple to light scalar or vector boson. Asymmetric Dark Matter annihilation cross section is enhanced by the Sommerfeld effect which exists due to the distortion of wavefunction of asymmetric Dark Matter particle and anti--particle by long--range interactions. The impacts of Sommerfeld enhancement on the relic densities of asymmetric Dark Matter particle and anti--particle are discussed. The effect of kinetic decoupling on the relic density is also probed when the annihilation cross section is enhanced by Sommerfeld enhancement. Finally, the constraints on the parameter space is given by using the observational data of Dark Matter.