2025/09/03 by Bikai Gao, Gao, Bikai, Michał Marczenko +1 · 1 citation
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Nuclear Theory (nucl-th) #Pulsars and Gravitational Waves Research #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2509.03138
openalex publication_date 2025/09/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the appearance of quark degrees of freedom in dense isospin-symmetric nuclear matter. We employ the parity doublet model to incorporate chiral dynamics. Specifically, we contrast quarkyonic matter, in which quarks occupy states above the nucleon Fermi surface, with baryquark matter, in which quarks populate states inside the nucleonic Fermi sea. We find that while baryquark matter is generally energetically favored over quarkyonic matter, the self-consistent treatment of the momentum-space shell reveals that purely hadronic matter provides the lowest free energy up to densities well beyond nuclear saturation. Consequently, the contribution of quarks is not relevant within the model's domain of applicability, even though chiral symmetry becomes restored. This demonstrates that the onset of quark degrees of freedom and the restoration of chiral symmetry need not coincide.