Document Type


Publication Date




Publication Title

Physical Review C






054908 (1-16)


A systematic study is presented for centrality, transverse momentum pT, and pseudorapidity (η) dependence of the inclusive charged hadron elliptic flow v2 at midrapidity (|η| < 1.0) in Au + Au collisions at √ˢᴺᴺ = 7.7, 11.5, 19.6, 27, and 39 GeV. 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 (v2{4}), are presented to investigate nonflow correlations and v2 fluctuations. We observe that the difference between v2{2} and v2{4} is smaller at the lower collision energies. Values of v2, scaled by the initial coordinate space eccentricity, v2/ϵ, as a function of pT 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 √ˢᴺᴺ = 62.4 and 200 GeV) and at the Large Hadron Collider (Pb + Pb collisions at √ˢᴺᴺ = 2.76 TeV). The v2(pT) values for fixed pT rise with increasing collision energy within the pT range studied (<2 GeV/c). A comparison to viscous hydrodynamic simulations is made to potentially help understand the energy dependence of v2(pT). We also compare the v2 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.


"Yes, the author or the author's employer may use all or part of the APS published article, including the APS-prepared version (e.g., the PDF from the online journal) without revision or modification, on the author's or employer's website as long as a fee is not charged. If a fee is charged, then APS permission must be sought. In all cases, the appropriate bibliographic citation and notice of the APS copyright must be included."

© American Physical Society

Original Publication Citation

Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., . . . Zyzak, M. (2012). Inclusive charged hadron elliptic flow in Au + Au collisions at √ˢᴺᴺ = 7.7-39 GeV. Physical Review C, 86(5), 054908. doi:10.1103/PhysRevC.86.054908

Included in

Nuclear Commons