Saturation of azimuthal anisotropy in Au+Au collisions at root s(NN) = 62 – 200 GeV.

New measurements are presented for charged hadron azimuthal correlations at midrapidity in Au+Au collisions at {radical}(s{sub NN})=62.4 and 200 GeV. They are compared to earlier measurements obtained at {radical}(s{sub NN})=130 GeV and in Pb+Pb collisions at {radical}(s{sub NN})=17.2 GeV. Sizeable anisotropies are observed with centrality and transverse momentum (p{sub T}) dependence characteristic of elliptic flow (v{sub 2}). For a broad range of centralities, the observed magnitudes and trends of the differential anisotropy, v{sub 2}(p{sub T}), change very little over the collision energy range {radical}(s{sub NN})=62-200 GeV, indicating saturation of the excitation function for v{sub 2} at these energies. Such a saturation may be indicative of the dominance of a very soft equation of state for {radical}(s{sub NN}){approx}60-200 GeV.