Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sqrt(sNN) = 200 GeV
Abstract
Differential measurements of the elliptic (v2) and hexadecapole (v4) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum (pT) and collision centrality or the number of participant nucleons (Npart) for Au+Au collisions at sqrt(sNN)=200 GeV. The v2,4 measurements at pseudorapidity |η|<=0.35 obtained with four separate reaction plane detectors positioned in the range 1.0<|η|<3.9 show good agreement, indicating the absence of significant η-dependent nonflow perturbations. Sizable values for v4(pT) are observed with a ratio v4(pT,Npart)/v22(pT,Npart)~0.8 for 50<Npart<200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For Npart>200 this ratio increases up to 1.7 in the most central collisions.