Effect of temperature-dependent eta/s on flow anisotropies

TL;DR

This study explores how a temperature-dependent shear viscosity to entropy density ratio influences flow anisotropies v_2 and v_4 in ultrarelativistic heavy-ion collisions, revealing different sensitivities at various energies.

Contribution

It introduces a detailed analysis of temperature-dependent eta/s effects on flow anisotropies, highlighting the differential impact on v_2 and v_4 across collision energies.

Findings

v_4 is more sensitive to low-temperature viscosity than v_2

v_2 is affected by viscosity near the phase transition at RHIC

Higher collision energies increase the influence of QGP viscosity on v_2

Abstract

We investigate the effects of a temperature-dependent shear viscosity over entropy density ratio eta/s on the flow anisotropy coefficients v_2 and v_4 in ultrarelativistic heavy-ion collisions at RHIC and LHC. We find that v_4 is more sensitive to the viscosity at low temperatures than v_2. At RHIC v_2 is mostly affected by the viscosity around the phase transition, but the larger the collision energy, the more the quark-gluon plasma viscosity affects v_2.