2025/06/12 by Chung, Yi · 1 citation
#Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2506.10928
The similarity between dark matter and baryon energy densities suggests the existence of a dark sector analogous to the visible QCD sector. In addition, small-scale structure issues can be addressed by dark matter self-interactions with a cross section comparable to that of QCD. Both observations point to a GeV-scale dark QCD sector. In this letter, guided by these two coincidences, we investigate how a chiral dark QCD model with a MeV-scale dark photon can resolve the core-cusp problem. A potential third coincidence, associated with the latest measurement of N\rm eff being lower than the Standard Model prediction, is also discussed. Current constraints leave a finite window in the parameter space, which can be tested by future experiments such as Gamma Factory.