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Title: Elliptic Flow of Identified Hadrons in Au+Au Collisions at sqrt(s_NN)=200 GeV

Authors:
Publication Date:
Research Org.:
ORNL Oak Ridge National Laboratory
Sponsoring Org.:
USDOE; COLLIDER-ACCELERATOR & PHYS. DEPTS. AT BNL
OSTI Identifier:
829393
Report Number(s):
P03-117515
Journal ID: 0031-9007
DOE Contract Number:
AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 91
Country of Publication:
United States
Language:
English

Citation Formats

Adler, S.S.. Elliptic Flow of Identified Hadrons in Au+Au Collisions at sqrt(s_NN)=200 GeV. United States: N. p., 2003. Web. doi:10.1103/PhysRevLett.91.182301.
Adler, S.S.. Elliptic Flow of Identified Hadrons in Au+Au Collisions at sqrt(s_NN)=200 GeV. United States. doi:10.1103/PhysRevLett.91.182301.
Adler, S.S.. Wed . "Elliptic Flow of Identified Hadrons in Au+Au Collisions at sqrt(s_NN)=200 GeV". United States. doi:10.1103/PhysRevLett.91.182301.
@article{osti_829393,
title = {Elliptic Flow of Identified Hadrons in Au+Au Collisions at sqrt(s_NN)=200 GeV},
author = {Adler, S.S.},
abstractNote = {},
doi = {10.1103/PhysRevLett.91.182301},
journal = {Physical Review Letters},
number = ,
volume = 91,
place = {United States},
year = {Wed Oct 01 00:00:00 EDT 2003},
month = {Wed Oct 01 00:00:00 EDT 2003}
}
  • Differential measurements of the elliptic (v{sub 2}) and hexadecapole (v{sub 4}) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum (p{sub T}) and collision centrality or number of participant nucleons (N{sub part}) for Au+Au collisions at {radical}s{sub NN} = 200 GeV. The v{sub 2,4} measurements at pseudorapidity |{eta}| {le} 0.35, obtained with four separate reaction-plane detectors positioned in the range 1.0 < |{eta}| < 3.9, show good agreement, indicating the absence of significant {Delta}{eta}-dependent nonflow correlations. Sizable values for v{sub 4}(p{sub T}) are observed with a ratio v{sub 4}(p{sub T},N{sub part})/v{sub 2}{sup 2}(p{sub T},N{sub part})more » {approx} 0.8 for 50 {le} N{sub part} {le} 200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For N{sub part} {ge} 200 this ratio increases up to 1.7 in the most central collisions.« less
  • Differential elliptic flow (v{sub 2}) for {phi} mesons and (anti)deuterons ({bar d})d is measured for Au+Au collisions at {radical}s{sub NN}=200 GeV. The v{sub 2} for {phi} mesons follows the trend of lighter {pi}{sup {+-}} and K{sup {+-}} mesons, suggesting that ordinary hadrons interacting with standard hadronic cross sections are not the primary driver for elliptic flow development. The v{sub 2} values for ({bar d})d suggest that elliptic flow is additive for composite particles. This further validation of the universal scaling of v{sub 2} per constituent quark for baryons and mesons suggests that partonic collectivity dominates the transverse expansion dynamics.
  • We present inclusive charged hadron elliptic flow (v{sub 2}) measured over the pseudorapidity range |{eta}| < 0.35 in Au+Au collisions at {radical}s{sub NN} = 200 GeV. Results for v{sub 2} are presented over a broad range of transverse momentum (p{sub T} = 0.2-8.0 GeV/c) and centrality (0-60%). To study nonflow effects that are correlations other than collective flow, as well as the fluctuations of v{sub 2}, we compare two different analysis methods: (1) the event-plane method from two independent subdetectors at forward (|{eta}| = 3.1-3.9) and beam (|{eta}| > 6.5) pseudorapidities and (2) the two-particle cumulant method extracted using correlationsmore » between particles detected at midrapidity. The two event-plane results are consistent within systematic uncertainties over the measured p{sub T} and in centrality 0-40%. There is at most a 20% difference in the v{sub 2} between the two event-plane methods in peripheral (40-60%) collisions. The comparisons between the two-particle cumulant results and the standard event-plane measurements are discussed.« less
  • The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured electrons with 0.3<p{sub T}<9 GeV/c at midrapidity (|y|<0.35) from heavy-flavor (charm and bottom) decays in Au+Au collisions at {radical}(s{sub NN})=200 GeV. The nuclear modification factor R{sub AA} relative to p+p collisions shows a strong suppression in central Au+Au collisions, indicating substantial energy loss of heavy quarks in the medium produced at RHIC energies. A large azimuthal anisotropy v2 with respect to the reaction plane is observed for 0.5<p{sub T}<5 GeV/c indicating substantial heavy-flavor elliptic flow. Both R{sub AA} and v{sub 2} show a p{sub T} dependence differentmore » from those of neutral pions. A comparison to transport models which simultaneously describe R{sub AA}(p{sub T}) and v{sub 2}(p{sub T}) suggests that the viscosity to entropy density ratio is close to the conjectured quantum lower bound, i.e., near a perfect fluid.« less