Relativistic hydrodynamics in heavy-ion collisions: general aspects and recent developments

TL;DR

This paper reviews recent advances in relativistic hydrodynamics modeling of heavy-ion collisions, focusing on key ingredients, observables, and new developments like fluctuations and flow in small systems.

Contribution

It provides a comprehensive overview of recent theoretical and computational progress in relativistic hydrodynamics applied to heavy-ion collision experiments.

Findings

Viscosity significantly affects particle spectra and flow observables.

Event-by-event fluctuations influence flow measurements and correlations.

Flow phenomena are observed even in small systems like proton-proton collisions.

Abstract

Relativistic hydrodynamics has been quite successful in explaining the collective behaviour of the QCD matter produced in high energy heavy-ion collisions at RHIC and LHC. We briefly review the latest developments in the hydrodynamical modeling of relativistic heavy-ion collisions. Essential ingredients of the model such as the hydrodynamic evolution equations, dissipation, initial conditions, equation of state, and freeze-out process are reviewed. We discuss observable quantities such as particle spectra and anisotropic flow and effect of viscosity on these observables. Recent developments such as event-by-event fluctuations, flow in small systems (proton-proton and proton-nucleus collisions), flow in ultra central collisions, longitudinal fluctuations and correlations and flow in intense magnetic field are also discussed.