Charmed Meson Structure across Crossover from SU(4) Polyakov Quark Meson Model with Isospin Asymmetry

TL;DR

This paper extends the Polyakov Quark Meson model to include charm quarks and isospin asymmetry, providing insights into the QCD phase diagram, meson masses, and thermodynamics at high temperatures relevant to heavy-ion collisions.

Contribution

The study introduces an SU(4) PQM model with charm quarks and isospin asymmetry, enhancing the understanding of QCD matter and phase transitions at high temperatures.

Findings

Decreased pseudo-critical temperature with increasing isospin chemical potential.

Charm sector remains thermally stable over a wide temperature range.

Model shows good qualitative agreement with lattice QCD results.

Abstract

The Polyakov Quark Meson (PQM) model is extended to SU(4) flavor symmetry by incorporating the charm quark and introducing a finite isospin asymmetry. This model incorporates the light, strange, and charm chiral condensates, along with the Polyakov-loop variables, to describe the confinement--deconfinement phase transition in a thermal and dense QCD medium. The inclusion of the charm quark condensate enhances the capability of the SU(4) PQM model to explore the spatial and thermal resolution of the chiral phase structure, particularly in the crossover and high-temperature regimes. We construct the QCD phase diagram ($T/T_\chi-\mu_I/m_\pi$) plane, indicating a decrease in the pseudo-critical temperature as the isospin chemical potential increases and explore thermodynamic quantities related to the QCD equation of state at very high temperatures. Fluctuations of quark flavors, conserved charges and baryon-charm correlations are studied across a wide temperature range. The SU(4) PQM model exhibits good qualitative agreement with lattice QCD calculations. Additionally, we calculate the meson mass spectrum at zero and finite temperature, showing that the charm sector remains thermally stable over a wide temperature range. Overall, this study highlights the capability of the SU(4) PQM model to describe key features of QCD matter at high temperatures and its relevance to heavy-ion collisions and astrophysical studies.