Abstract

We present high precision measurements of elliptic flow near midrapidity (vertical bar y vertical bar 1.0) for multistrange hadrons and phi meson as a function of centrality and transverse momentum in Au + Au collisions at center of mass energy root S (NN) = 200 GeV. We observe that the transverse momentum dependence of phi and Omega v(2) is similar to that of pi and p, respectively, which may indicate that the heavier strange quark flows as strongly as the lighter up and down quarks. This observation constitutes a clear piece of evidence for the development of partonic collectivity in heavy-ion collisions at the top RHIC energy. Number of constituent quark scaling is found to hold within statistical uncertainty for both 0%-30% and 30%-80% collision centrality. There is an indication of the breakdown of previously observed mass ordering between phi and proton v(2) at low transverse momentum in the 0%-30% centrality range, possibly indicating late hadronic interactions affecting the proton v(2).