Influence of the shear viscosity of the quark-gluon plasma on elliptic flow in ultrarelativistic heavy-ion collisions

TL;DR

This study examines how the temperature-dependent shear viscosity affects the elliptic flow in heavy-ion collisions, revealing different sensitivities at RHIC and LHC energies.

Contribution

It demonstrates the varying influence of shear viscosity in different phases of the collision, highlighting the importance of QGP viscosity at LHC energies.

Findings

Elliptic flow at RHIC is dominated by hadronic phase viscosity.

At LHC, elliptic flow is sensitive to QGP viscosity.

Elliptic flow shows phase-dependent sensitivity to shear viscosity.

Abstract

We investigate the influence of a temperature-dependent shear viscosity over entropy density ratio eta/s on the transverse momentum spectra and elliptic flow of hadrons in ultrarelativistic heavy-ion collisions. We find that the elliptic flow in sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC is dominated by the viscosity in the hadronic phase and in the phase transition region, but largely insensitive to the viscosity of the quark-gluon plasma (QGP). At the highest LHC energy, the elliptic flow becomes sensitive to the QGP viscosity and insensitive to the hadronic viscosity.