Viscosity from elliptic flow: Clearing the path towards precision

Abstract

Using viscous relativistic hydrodynamics we show that systematic studies of the impact parameter dependence of the eccentricity-scaled elliptic flow ${v}_{2}/\ensuremath{\varepsilon}$ can distinguish between different models for the calculation of the initial source eccentricity $\ensuremath{\varepsilon}$. This removes the largest present uncertainty in the extraction of the specific viscosity of the matter created in relativistic heavy-ion collisions from precise elliptic-flow measurements.