Fluctuations and correlations in heavy-ion collisions as a probe of the QCD phase structure

Abstract

The phase structure of QCD and the nature of the transition between ordinary hadronic matter and the deconfined state of quark-gluon plasma remain among the key open questions in high-energy physics. This talk will explore how these questions can be addressed using fluctuation observables, with a focus on event-by-event fluctuations in heavy-ion collisions and the search for the QCD critical point at finite baryon number density. I will discuss the dynamical description of proton number cumulants and correlation functions in heavy-ion collisions based on relativistic hydrodynamics, and will put these predictions in the context of new STAR data from BES-II.