Equation of state for QCD with a critical point from the 3D Ising Model

TL;DR

This paper develops a QCD equation of state incorporating a critical point by mapping the 3D Ising model's scaling form to QCD, enabling improved hydrodynamic simulations at finite density.

Contribution

It introduces a novel method to incorporate critical behavior into the QCD equation of state using a 3D Ising model mapping, compatible with lattice QCD results.

Findings

Constructed a family of equations of state with critical behavior

Matches lattice QCD calculations at zero chemical potential

Suitable for hydrodynamic simulations of heavy ion collisions

Abstract

Current knowledge of the finite-density QCD equation of state from first principles is limited to a Taylor expansion in the baryonic chemical potential around $\mu_B=0$. By means of a scaling form for the equation of state of the 3D Ising model and a non-universal, parametrized map to QCD coordinates, we construct a family of equations of state matching state of the art first principle Lattice QCD calculations and including the correct critical behavior, which can be readily employed in hydrodynamical simulations of heavy ion collisions at finite density, covering most of the BES range at RHIC. This contribution reports on work done within the Fluctuations/Equation of State working group of the BEST Collaboration.