Thermal Quarks and Polyakov Loops in Two-Color Dense QCD

We study confinement and deconfinement in dense two-color QCD by analyzing the dynamics of thermal quarks and gluons. The Polyakov loop is used as a probe of the relevant thermal excitations, distinguishing quark- and hadron-dominated regimes in dense matter. To describe the Polyakov loop, we adopt both lattice-informed phenomenological models and the massive Yang–Mills framework. After calibrating these models at zero density, we investigate in-medium modifications of the Polyakov loops and gluon propagators at finite temperature and density. Diquark gaps control the screening at zero temperature, whereas the screening due to thermal quarks is sensitive to the Polyakov loop. Inclusion of the Polyakov loop helps to reproduce lattice data at low temperature, suggesting that thermal excitations are predominantly hadronic rather than uncorrelated quarks.