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Title: Azimuthal anisotropy in Cu+Au collisions at √s NN = 200 GeV

Abstract

Here, the azimuthal anisotropic flow of identified and unidentified charged particles has been systematically studied in Cu+Au collisions at √s NN = 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 √s NN = 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 natural explanation in a picture of the directed flow originating partly due the “tilted source” and partly due to the rapidity dependent asymmetry in the initial density distribution. Charge-dependence of the hpxi was also observed in Cu+Au collisions, indicating an effect of the initial electric field created bymore » 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 √s NN = 2.76 TeV, indicating a similar magnitude of dipole-like 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.« less

Authors:
 [1]
  1. AGH Univ. of Science and Technology, Cracow (Poland). et al.
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Contributing Org.:
STAR Collaboration
OSTI Identifier:
1460829
Alternate Identifier(s):
OSTI ID: 1462294; OSTI ID: 1477346
Report Number(s):
BNL-207844-2018-JAAM
Journal ID: ISSN 2469-9985; TRN: US1901924
Grant/Contract Number:  
SC0012704; AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 98; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats

Adamczyk, Leszek. Azimuthal anisotropy in Cu+Au collisions at √sNN = 200 GeV. United States: N. p., 2018. Web. doi:10.1103/PhysRevC.98.014915.
Adamczyk, Leszek. Azimuthal anisotropy in Cu+Au collisions at √sNN = 200 GeV. United States. doi:10.1103/PhysRevC.98.014915.
Adamczyk, Leszek. Tue . "Azimuthal anisotropy in Cu+Au collisions at √sNN = 200 GeV". United States. doi:10.1103/PhysRevC.98.014915. https://www.osti.gov/servlets/purl/1460829.
@article{osti_1460829,
title = {Azimuthal anisotropy in Cu+Au collisions at √sNN = 200 GeV},
author = {Adamczyk, Leszek},
abstractNote = {Here, 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 natural explanation in a picture of the directed flow originating partly due the “tilted source” and partly due to the rapidity dependent asymmetry in the initial density distribution. Charge-dependence of the hpxi was also observed in Cu+Au collisions, indicating 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 dipole-like 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.},
doi = {10.1103/PhysRevC.98.014915},
journal = {Physical Review C},
number = ,
volume = 98,
place = {United States},
year = {2018},
month = {7}
}

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