Flow in heavy-ion collisions - Theory Perspective

TL;DR

This paper reviews recent advances in relativistic hydrodynamics applied to heavy-ion collisions at RHIC and LHC, focusing on higher-order theories, temperature-dependent viscosities, and event-by-event simulations to better understand quark-gluon plasma properties.

Contribution

It introduces developments beyond second-order hydrodynamics, including temperature-dependent viscosities and coupling with microscopic models, enhancing the modeling of heavy-ion collision dynamics.

Findings

Higher harmonic flow coefficients computed with event-by-event simulations.

Comparison of hydrodynamic models with experimental data from RHIC and LHC.

Insights into initial state conditions and medium properties of quark-gluon plasma.

Abstract

I review recent developments in the field of relativistic hydrodynamics and its application to the bulk dynamics in heavy-ion collisions at the Relativistic Heavy- Ion Collider (RHIC) and the Large Hadron Collider (LHC). In particular, I report on progress in going beyond second order relativistic viscous hydrodynamics for conformal fluids, including temperature dependent shear viscosity to entropy density ratios, as well as coupling hydrodynamic calculations to microscopic hadronic rescattering models. I describe event-by-event hydrodynamic simulations and their ability to compute higher harmonic flow coefficients. Combined comparisons of all harmonics to recent experimental data from both RHIC and LHC will potentially allow to determine the desired details of the initial state and the medium properties of the quark-gluon plasma produced in heavy-ion collisions.