Anisotropic collective phenomena in ultra-relativistic nuclear collisions

TL;DR

This paper reviews recent advances in understanding anisotropic phenomena in ultra-relativistic nuclear collisions, focusing on viscous hydrodynamics, initial state fluctuations, and novel correlations related to fundamental symmetries.

Contribution

It highlights recent progress in modeling and interpreting anisotropic flow and correlations, emphasizing the role of initial conditions and fluctuations in heavy-ion collisions.

Findings

Significant progress in viscous hydrodynamics calculations

Clarification of initial eccentricity and flow fluctuations

Observation of azimuthal correlations sensitive to parity violation

Abstract

For a detailed review of this subject I refer to a recent paper \cite{Voloshin:2008dg}; in this talk I only very briefly comment on a few most important questions: (a) Very recent significant progress in viscous hydrodynamics calculations (b) Initial eccentricity/flow fluctuations, the effect of which has been clarified recently (c) Initial conditions, in particular the role of the gradients in the initial velocity field, (d) Puzzling system size dependence of directed flow (e) Azimuthal correlations that are sensitive to the strong parity violation (f) Future measurements at RHIC and LHC, including pp-collisions