Centrality dependence of identified particle elliptic flow in relativistic heavy ion collisions at $\sqrt{s_{NN}}$=7.7–62.4 GeV

The collaboration
Phys.Rev.C 93 (2016) 014907, 2016.

Abstract (data abstract)
BNL-RHIC. Elliptic flow ($v_{2}$) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at $\sqrt{s_{NN}}$ = 7.7-62.4 GeV are presented for three centrality classes. The centrality dependence and the data at $\sqrt{s_{NN}}$ = 14.5 GeV are new. Except at the lowest beam energies we observe a similar relative $v_{2}$ baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger $v_{2}$ for most particles relative to antiparticles, already observed for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with A Multiphase Transport Model and fit with a Blast Wave model.

Version 2 modifications: Include data points for Figs. 6 and 7.