Centrality and transverse momentum dependence of elliptic flow of multi-strange hadrons and $\varphi$ meson in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV

We present high precision measurements of elliptic flow near midrapidity ($\mathrm{\mid }y\mathrm{\mid }<1.0$) for multi-strange hadrons and $\varphi$ meson as a function of centrality and transverse momentum in Au+Au collisions at center of mass energy $\sqrt{s_{NN}}=$ 200 GeV. We observe that the transverse momentum dependence of $\varphi$ and $\mathrm{\Omega }$ $v_2$ 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$\mathrm{\%}$ and 30-80$\mathrm{\%}$ collision centrality. There is an indication of the breakdown of previously observed mass ordering between $\varphi$ and proton $v_2$ at low transverse momentum in the 0-30$\mathrm{\%}$ centrality range, possibly indicating late hadronic interactions affecting the proton $v_2$.