SIMP model at NNLO in chiral perturbation theory

TL;DR

This paper assesses the viability of a composite dark matter model using advanced chiral perturbation theory calculations, revealing that higher order corrections challenge the model's compatibility with observational constraints.

Contribution

It provides a detailed NNLO chiral perturbation theory analysis of SIMP dark matter models, highlighting the importance of higher order effects in evaluating their phenomenological viability.

Findings

Higher order corrections increase tension with constraints.

Leading order analysis is insufficient for viability assessment.

The simplest SIMP models face significant challenges from phenomenological constraints.

Abstract

We investigate the phenomenological viability of a recently proposed class of composite dark matter models where the relic density is determined by 3 to 2 number-changing processes in the dark sector. Here the pions of the strongly interacting field theory constitute the dark matter particles. By performing a consistent next-to-leading and next-to-next-to-leading order chiral perturbative investigation we demonstrate that the leading order analysis cannot be used to draw conclusions about the viability of the model. We further show that higher order corrections substantially increase the tension with phenomenological constraints challenging the viability of the simplest realisation of the strongly interacting massive particle (SIMP) paradigm.