Impact of bound states on non-thermal dark matter production

TL;DR

This paper investigates how non-perturbative effects like Sommerfeld enhancement and bound state formation influence the early Universe production of non-thermal dark matter, revealing significant impacts on model parameters and collider testability.

Contribution

It demonstrates the substantial suppression of dark matter yield due to non-perturbative effects in simplified models with t-channel mediators, altering the cosmological parameter space.

Findings

Dark matter yield is significantly suppressed by non-perturbative effects.

Revised constraints on non-thermal dark matter models from LHC bounds.

Testing these models at the LHC is more challenging than previously thought.

Abstract

We explore the impact of non-perturbative effects, namely Sommerfeld enhancement and bound state formation, on the cosmological production of non-thermal dark matter. For this purpose, we focus on a class of simplified models with t-channel mediators. These naturally combine the requirements for large corrections in the early Universe, i.e. beyond the Standard Model states with long range interactions, with a sizable new physics production cross section at the LHC. We find that the dark matter yield of the superWIMP mechanism is suppressed considerably due to the non-perturbative effects under consideration. This leads to a significant shift in the cosmologically preferred parameter space of non-thermal dark matter in these models. We also revisit the implications of LHC bounds on long-lived particles associated with non-thermal dark matter and find that testing this scenario at the LHC is a bigger challenge than previously anticipated.