A data-driven method was applied to Au+Au collisions at √sNN = 200 GeV made with the STAR detector at RHIC to isolate pseudorapidity distance Δη-dependent and Δη-independent correlations by using two- and four-particle azimuthal cumulant measurements. We identified a Δη-independent component of the correlation, which is dominated by anisotropic flow and flow fluctuations. It was also found to be independent of η within the measured range of pseudorapidity |η| < 1. In 20–30% central Au+Au colli- sions, the relative flow fluctuation was found to be 34% ± 2%(stat.) ± 3%(sys.) for particles with transverse momentum PT less than 2 GeV/c. The Δη-dependent part, attributed to nonflow correlations, is found to be 5% ± 2%(sys.) relative to the flow of the measured second harmonic cumulant at |Δη| > 0.7.

Document Type


Publication Date


Notes/Citation Information

Published in Physics Letters B, v. 745, p. 40-47.

© 2015 The Authors. Published by Elsevier B.V.

This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3.

Due to the large number of authors involved, only the first 10 and the ones affiliated with the University of Kentucky are listed in the author section above. The authors of this article are collectively known as STAR Collaboration. To see a full list of authors, please download this article or visit: http://dx.doi.org/10.1016/j.physletb.2015.04.033

Digital Object Identifier (DOI)


Funding Information

We thank the RHIC Operations Group and RCF at BNL, the NERSC Center at LBNL, the KISTI Center in Korea, and the Open Science Grid consortium for providing resources and support. This work was supported in part by the Offices of NP and HEP within the U.S. DOEOffice of Science, the U.S. NSF, CNRS/IN2P3, FAPESPCNPq of Brazil, the Ministry of Education and Science of the Russian Federation, NNSFC, CAS, MoST and MoE of China, the Korean Research Foundation, GA and MSMT of the Czech Republic, FIAS of Germany, DAE, DST, and CSIR of India, the National Science Centre of Poland, National Research Foundation (NRF-2012004024), the Ministry of Science, Education and Sports of the Republic of Croatia, and RosAtom of Russia.