Scale for the Phase Diagram of Quantum Chromodynamics

TL;DR

This paper compares lattice QCD predictions with experimental data from heavy-ion collisions to identify the crossover temperature, providing a scale for the QCD phase diagram and evidence of thermalization.

Contribution

It offers a novel comparison between theoretical lattice QCD calculations and experimental fluctuation data to determine the QCD phase transition temperature.

Findings

Evidence for thermalization in heavy-ion collisions

Identification of the crossover temperature for QCD matter

Establishment of a scale for the QCD phase diagram

Abstract

Matter described by Quantum Chromodynamics (QCD), the theory of strong interactions, may undergo phase transitions when its temperature and the chemical potentials are varied. QCD at finite temperature is studied in the laboratory by colliding heavy-ions at varying beam energies. We present a test of QCD in the non-perturbative domain through a comparison of thermodynamic fluctuations predicted in lattice computations with the experimental data of baryon number distributions in high-energy heavy-ion collisions. This study provides evidence for thermalization in these collisions, and allows us to find the crossover temperature between normal nuclear matter and a deconfined phase called the quark gluon plasma. This value allows us to set a scale for the phase diagram of QCD.