Inclusive charged hadron elliptic flow in Au + Au collisions at [ over S [ subscript NN ] ] = 7 . 7 – 39 GeV

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. A systematic study is presented for centrality, transverse momentum (p T), and pseudorapidity (η) dependence of the inclusive charged hadron elliptic flow (v 2) at midrapidity (|η| < 1.0) in Au + Au collisions at The results obtained with different methods, including correlations with the event plane reconstructed in a region separated by a large pseudorapidity gap and four-particle cumulants (v 2 {4}), are presented to investigate nonflow correlations and v 2 fluctuations. We observe that the difference between v 2 {2} and v 2 {4} is smaller at the lower collision energies. Values of v 2 , scaled by the initial coordinate space eccentricity, v 2 /ε, as a function of p T are larger in more central collisions, suggesting stronger collective flow develops in more central collisions, similar to the results at higher collision energies. These results are compared to measurements at higher energies at the Relativistic Heavy Ion Collider (√ s NN = 62.4 and 200 GeV) and at the Large Hadron 054908-2 INCLUSIVE CHARGED HADRON ELLIPTIC FLOW IN Au. .. Collider (Pb + Pb collisions at √ s NN = 2.76 TeV). The v 2 (p T) values for fixed p T rise with increasing collision energy within the p T range studied (<2 GeV/c). A comparison to viscous hydrodynamic simulations is made to potentially help understand the energy dependence of v 2 (p T). We also compare the v 2 results to UrQMD and AMPT transport model calculations, and physics implications on the dominance of partonic versus hadronic phases in the system created at beam energy scan energies are discussed.