Azimuthal anisotropy in Cu+Au collisions at √sNN=200 GeV

• Verfasst von: Adamczyk, Leszek [VerfasserIn]
• Verfasst von: Deppner, Ingo Martin [VerfasserIn]
• Verfasst von: Herrmann, Norbert [VerfasserIn]
• Titel: Azimuthal anisotropy in Cu+Au collisions at √sNN=200 GeV
• Körperschaft: STAR Collaboration [VerfasserIn]
• Verf.angabe: L. Adamczyk, I.M. Deppner, N. Herrmann [und 350 weitere] (STAR Collaboration)
• E-Jahr: 2018
• Jahr: 31 July 2018
• Umfang: 22 S.
• Fussnoten: Im Titel steht der Ausdruck "sNN" unter dem Wurzelsymbol, "NN" ist dabei tiefgestellt ; Gesehen am 05.07.2019
• Titel Quelle: Enthalten in: Physical review
• Ort Quelle: Woodbury, NY : Inst., 2016
• Jahr Quelle: 2018
• Band/Heft Quelle: 98(2018,1) Artikel-Nummer 014915, 22 Seiten
• ISSN Quelle: 2470-0029
• DOI: doi:10.1103/PhysRevC.98.014915
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1668669250

Abstract

The azimuthal anisotropic flow of identified and unidentified charged particles has been systematically studied in Cu+Au collisions at √sNN=200 GeV for harmonics n=1-4 in the pseudorapidity range |η|<1. The directed flow in Cu+Au collisions is compared with the rapidity-odd and, for the first time, the rapidity-even components of charged particle directed flow in Au+Au collisions at √sNN=200 GeV. The slope of the directed flow pseudorapidity dependence in Cu+Au collisions is found to be similar to that in Au+Au collisions, with the intercept shifted toward positive pseudorapidity values, i.e., the Cu-going direction. The mean transverse momentum projected onto the spectator plane ⟨px⟩ in Cu+Au collision also exhibits approximately linear dependence on pseudorapidity with the intercept at about η≈−0.4 (shifted from zero in the Au-going direction), closer to the rapidity of the Cu+Au system center of mass. The observed dependencies find a natural explanation in a picture of the directed flow originating partly due the “tilted source” and partly due to the asymmetry in the initial density distribution. A charge dependence of ⟨px⟩ was also observed in Cu+Au collisions, consistent with an effect of the initial electric field created by charge difference of the spectator protons in two colliding nuclei. The rapidity-even component of directed flow in Au+Au collisions is close to that in Pb+Pb collisions at √sNN=2.76 TeV, indicating a similar magnitude of dipolelike fluctuations in the initial-state density distribution. Higher harmonic flow in Cu+Au collisions exhibits similar trends to those observed in Au+Au and Pb+Pb collisions and is qualitatively reproduced by a viscous hydrodynamic model and a multiphase transport model. For all harmonics with n≥2 we observe an approximate scaling of vn with the number of constituent quarks; this scaling works as well in Cu+Au collisions as it does in Au+Au collisions.