Speaker
Description
A wide variety of recent measurements from small systems indicate that there are collective flow phenomena in these systems, which are well described by hydrodynamics. However, it is widely understood that all flow measurements are affected by non-flow correlations. In order to disentangle the genuine hydrodynamical flow from other contributions, we have systematically studied the $v_2$ as a function of $p_T$ and $\eta$ in p+Au and d+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV with a mixture of different detector combinations and by comparing several non-flow subtraction methods. We have also measured 4-particle cumulants in p+Au and d+Au at $\sqrt{s_{NN}}$ = 200 GeV with subevents, which kinematically suppress non-flow via removal of short-range correlations. As found in heavy ion collisions, the quark mass dependence of the flow will further provide an evidence of collective effects. PHENIX has measured $v_2$ vs $p_T$ of muons at forward rapidity originating from heavy quark decays in d+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. We will show these results and discuss implications for the underlying mechanism that drives both light and heavy quark collectivity.
