The Reach of Threshold-Corrected Dark QCD

TL;DR

This paper extends a dark QCD model by calculating threshold corrections to the renormalization group flow, revealing a broader parameter space where the model can explain the observed dark matter relic density.

Contribution

It introduces explicit threshold corrections to the RG flow in a dark QCD model, expanding the viable parameter space for explaining dark matter.

Findings

Threshold corrections significantly affect the RG flow.

A wider range of models can account for relic density.

Many models remain consistent with observations after correction.

Abstract

We consider a recently-proposed model which posits the existence of composite dark matter, wherein dark "quarks" transforming as fundamentals under an $SU(3)_d$ gauge group undergo a confining phase and form dark baryons. The model attempts to explain both the $\mathcal{O}(1)$ relic density ratio, $\Omega_{\mathrm{dark}}/\Omega_{\mathrm{baryon}}\sim 5.4$, as well as the asymmetric production of both dark and baryonic matter via leptogenesis. Though the solution of $\beta$ functions for $SU(3)_c$ and $SU(3)_d$ constitutes the main drive of the model, no threshold corrections were taken into account as the renormalization scale crosses the mass threshold of the heavy new fields in the model. We extend this work by explicitly calculating the threshold-corrected renormalization-group flow for the theory using an effective-field matching technique. We find that the theory has a much wider range of applicability than previously thought, and that a significant fraction of models (defined by the number of fields contained therein) is able to account for the observed relic density.