Elliptic flow at energies available at the CERN Large Hadron Collider: Comparing heavy-ion data to viscous hydrodynamic predictions

摘要

I compare the first viscous hydrodynamic prediction for integrated ellipticflow in Pb-Pb collisions at the LHC with the first data released by the ALICEcollaboration. These new data are found to be consistent with hydrodynamicextrapolations of RHIC data with no change in medium parameters (e.g., averageviscosity). I also discuss how, in general, a precise comparison of data totheoretical calculations requires an understanding of some subtleties of themeasurement -- most notably the cut on transverse momentum of the particlesused and the differing sensitivities to flow fluctuations and non-flow effectsof the various measurement methods.