Thermodynamical Analysis of QGP Using Effective PNJL Model with Quasiparticle Approach

We study the thermodynamics of the quark–gluon plasma using an effective 2-flavor Polyakov–Nambu–Jona-Lasinio (PNJL) model extended by a quasiparticle description for quarks and gluons, incorporating temperature-dependent quark masses within the PNJL framework. Two variants, Quasiparticle Model-I and Quasiparticle Model-II, are implemented to investigate bulk thermodynamic observables such as pressure, energy density, entropy density, specific heat, and the speed of sound. The combined framework yields a robust baseline for the description of hot QGP dynamics in the high-temperature regime at vanishing chemical potential and zero magnetic field. Systematic comparison with lattice QCD results shows excellent agreement and a clear improvement over conventional PNJL implementations. We observe that both variants complement each other, offering mutually consistent insight into quasiparticle mass effects and medium response in the deconfined phase. This mutual consistency validates the physical foundation of the overall quasiparticle mechanism, reinforcing the credibility of the calculated Equation of State. Finally, the quasiparticle model extension improves PNJL from a descriptive tool to a more qualitative phenomenological approach, enabling an improved description of the strongly interacting quark–gluon plasma. Abstract Published by the Jagiellonian University 2026 authors