Inclusive charged hadron elliptic flow in Au + Au collisions at √sNN = 7.7–39 GeV

Scientific paper - Original scientific paper

• Author: L. Adamczyk
• Author: ...
• Author: Mirko Planinić
• Author: ...
• Author: Nikola Poljak
• Author: ...
• Author: M. Zyzak
• Collaboration: STAR Collaboration
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

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/ɛ, 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.

• Keywords (english): inclusive; flow; collision; STAR
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review C - Nuclear Physics
• Numbering: vol. 86, no. 5, 054908
• p-ISSN: 0556-2813
• e-ISSN: 1089-490X
• DOI: https://doi.org/10.1103/PhysRevC.86.054908
• URN:NBN: urn:nbn:hr:217:761051
• Publication: 2012
• Project: Number: 119-0982887-1006; Title (croatian): Istraživanje hadronskih sustava upotrebom relativističkih projektila; Leader: Mirko Planinić; Jurisdiction: Croatia; Funding stream: ZP
• Document URL: http://link.aps.org/doi/10.1103/PhysRevC.86.054908
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2012) by the American Physical Society. Received 25 June 2012; revised manuscript received 11 September 2012; published 15 November 2012.
• Created on: 2019-11-21 12:05:15