Measurements of azimuthal anisotropy and charged-particle multiplicity in d + Au collisions at √sNN=200, 62.4, 39, and 19.6 GeV

Scientific paper - Original scientific paper

• Author: C. Aidala
• Author: ...
• Author: Mirta Dumancic
• Author: ...
• Author: Mihael Makek
• Author: ...
• Author: L. Zou
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

We present measurements of the elliptic flow (v2) as a function of transverse momentum (pT), pseudorapidity (η), and centrality in d+Au collisions at √sNN=200, 62.4, 39, and 19.6 GeV. The beam-energy scan of d+Aucollisions provides a testing ground for the onset of flow signatures in small collision systems. We measure a nonzero v2 signal at all four collision energies, which, at midrapidity and low pT, is consistent with predictions from viscous hydrodynamic models. Comparisons with calculations from parton transport models (based on the ampt Monte Carlo generator) show good agreement with the data at midrapidity to forward (d-going) rapidities and low pT. At backward (Au-going) rapidities and pT>1.5GeV/c, the data diverges from ampt calculations of v2 relative to the initial geometry, indicating the possible dominance of nongeometry related correlations, referred to as nonflow. We also present measurements of the charged-particle multiplicity (dNch/dη) as a function of η in central d+Au collisions at the same energies. We find that in d+Au collisions at √sNN=200 GeV the v2 scales with dNch/dη over all η in the PHENIX acceptance. At √sNN=62.4, and 39 GeV, v2 scales with dNch/dη at midrapidity and forward rapidity, but falls off at backward rapidity. This departure from the dNch/dη scaling may be a further indication of nonflow effects dominating at backward rapidity.

• Keywords (english): azimuthal anisotropy; charged-particle multiplicity; d+Au; PHENIX; RHIC
• 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
• Numbering: vol. 96, no. 6, 064905
• p-ISSN: 2469-9985
• e-ISSN: 2469-9993
• DOI: https://doi.org/10.1103/PhysRevC.96.064905
• URN:NBN: urn:nbn:hr:217:751316
• Publication: 2017
• Document URL: https://journals.aps.org/prc/abstract/10.1103/PhysRevC.96.064905
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2017 American Physical Society. Received 24 August 2017; revised manuscript received 14 November 2017; published 26 December 2017.
• Created on: 2020-02-24 21:24:12