Probing bulk dynamics of the QGP with correlations and fluctuations

Abstract

Ultrarelativistic heavy-ion collisions are considered ideal environments for exploring the QCD phase diagram and probing the properties of the QGP as functions of temperature and baryon chemical potential. At the highest energies, such as those reached at the Large Hadron Collider (LHC), and near vanishing baryon chemical potential, the transition from hadronic matter to the QGP is expected to occur as a smooth crossover. At larger baryon chemical potentials, this crossover may end at a critical point, beyond which the transition becomes first order. Locating this critical point remains a central goal of current and future beam energy scan programs at RHIC, the CERN SPS, and FAIR/GSI. Fluctuation and correlation measurements are widely used to probe the QCD phase structure, as they provide information on the system's dynamical evolution and the nature of the phase transition at different regions of the phase diagram. This report presents an overview of recent experimental results across a broad energy range and discusses their implications for our current understanding of the QCD phase diagram.