Azimuthal anisotropy of π0 and η mesons in Au + Au collisions at sNN−−−√=200 GeV
Abstract
The azimuthal anisotropy coefficients v2 and v4 of π0 and η mesons are measured in Au + Au collisions at sNN−−−√=200 GeV as a function of transverse momentum pT (1-14 GeV/c) and centrality. The extracted v2 coefficients are found to be consistent between the two meson species over the measured pT range. The ratio of v4/v22 for π0 mesons is found to be independent of pT for 1-9 GeV/c, implying a lack of sensitivity of the ratio to the change of underlying physics with pT. Furthermore, the ratio of v4/v22 is systematically larger in central collisions, which may reflect the combined effects of fluctuations in the initial collision geometry and finite viscosity in the evolving medium.