Extending a Scaling Equation of State to QCD

TL;DR

This paper extends a scaling equation of state, inspired by the 3D Ising model, to QCD, aiming to identify the critical point in the QCD phase diagram through experimental data comparison.

Contribution

It combines a parametric scaling equation of state with a smooth crossover background for QCD, facilitating the search for a critical point in heavy ion collision data.

Findings

Potential to determine QCD critical exponents from experimental data

Provides a framework for identifying the QCD critical point

Enhances understanding of the QCD phase transition

Abstract

Whether Quantum Chromodynamics (QCD) exhibits a phase transition at finite temperature and density is an open question. It is important for hydrodynamic modeling of heavy ion collisions and neutron star mergers. Lattice QCD simulations have definitively shown that the transition from hadrons to quarks and gluons is a crossover when the baryon chemical potential is zero or small. We combine the parametric scaling equation of state, usually associated with the 3D Ising model, with a background equation of state based on a smooth crossover from hadrons to quarks and gluons. Comparison to experimental data from the Beam Energy Scan II at the Relativistic Heavy Ion Collider or in heavy ion experiments at other accelerators may allow the critical exponents and amplitudes in the scaling equation of state to be determined for QCD if a critical point exists.