Strangeness neutral equation of state with a critical point

TL;DR

This paper develops a family of QCD equations of state incorporating a critical point, consistent with lattice results and universal scaling, to aid hydrodynamic modeling of heavy-ion collisions.

Contribution

It introduces a flexible, lattice-based EoS with a tunable critical point aligned with the 3D Ising universality class for heavy-ion collision simulations.

Findings

EoS matches lattice QCD results up to $ ext{O}(oldsymbol{rac{ ext{B}}{4}})$

Critical point placement within RHIC Beam Energy Scan II range

Adjustable critical features via four free parameters

Abstract

We formulate a family of equations of state for Quantum Chromodynamics that exhibit critical features and obey the charge conservation conditions present in heavy-ion collisions (HICs). This construction utilizes the first-principle Lattice QCD (LQCD) results up to $\mathcal{O}(\mu_B^4)$ by matching the Taylor coefficients at each order. The criticality of the equation of state (EoS) is implemented based on the well-established principle of universal scaling behavior, where QCD belongs to the 3D Ising Model universality class. The critical point can be placed in a range of temperature and baryonic chemical potential relevant for the Beam Energy Scan II at RHIC. Furthermore, the strength of the critical features can be varied as well. This flexibility is embedded in four free parameters, that could potentially be constrained by the experimental data. We will discuss the features and versatility of our EoS, as well as present the relevant thermodynamic quantities which are important for hydrodynamical simulations of HICs.