On thermodynamically consistent quasiparticle model at finite chemical potential

TL;DR

This paper develops a thermodynamically consistent quasiparticle model at finite chemical potential, introducing a momentum-dependent effective mass as a novel solution to an integro-differential equation, expanding the model's generality beyond previous approaches.

Contribution

It proposes a new momentum-dependent effective mass in the quasiparticle model, derived from thermodynamic consistency, and adopts a bottom-up approach with analytic ansatzes at finite chemical potential.

Findings

The momentum dependence of the effective mass is more general than previous models.

The model maintains thermodynamic consistency through a novel integro-differential equation.

Physical quantities are derived without fitting to lattice QCD data at zero chemical potential.

Abstract

We explore the quasiparticle model at finite chemical potential related to Ru-Keng Su's distinguished contributions to the topic. Besides, we discuss recent developments in the model, and in particular, one argues that the effective mass of the quasiparticle might attain a specific form as a function of momentum, in addition to its dependence on temperature and chemical potential. Unlike the approaches based on the properties of underlying symmetry or renormalization group, the momentum dependence emerges as a special solution to an integro-differential equation resulting from the underlying thermodynamic consistency. Moreover, this special solution to the problem is shown to be more general than previously explored in the literature. Instead of fitting to the lattice QCD data at vanishing chemical potential, in this work, we adopt a ``bottom-up'' approach by assuming some analytic ansatzes that are manifestly thermodynamically consistent. The remaining physical quantities are subsequently derived, and possible implications are also addressed.