2025/01/25 by Zhaofeng Kang, J. Zhu, Jiang Zhu +2
Chemistry · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Molecular Spectroscopy and Structure #Molecular spectroscopy and chirality #Quantum, superfluid, helium dynamics
paper · pdf · doi:10.48550/arxiv.2501.15242
openalex publication_date 2025/01/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this article, for the first time, we explore the scenario that the dark-QCD sector has a large chemical potential μ (on the order of magnitude of temperature) of dark quarks. It leads to a complex-valued Polyakov loop and tilts the partial confinement effect, driving the dark-QCD phase transition to a first-order one in the early universe. We present a toy model via the Affleck-Dine mechanism that could generate degenerate dark quarks. Our study, in the framework of PNJL, focuses on the dynamical impacts of a large chemical potential on the chiral phase transition without turning on the KMT instanton term. We plot the phase diagram of the dark-QCD in the chiral limit. The resulting first-order phase transition actually refers to a chiral phase transition, with the transition to the confinement vacuum being a cross-over. Following the phase diagram, we find that increasing μ can considerably prolong the duration of the phase transition and also the release of latent heat, which together make the cosmic dark-QCD phase transition at the critical temperature above 1 GeV and below 100 GeV produce gravitational wave signal in the intermediate frequency band, which is well probable in space detectors such as BBO