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.
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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.
Adkins, James K.; Fatemi, Renee H.; Ramachandran, Suvarna; Abdelwahab, N. M.; Adamczyk, L.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; and Arkhipkin, D., "Isolation of Flow and Nonflow Correlations by Two- and Four-Particle Cumulant Measurements of Azimuthal Harmonics in √sNN=200 GeV Au+Au collisions" (2015). Physics and Astronomy Faculty Publications. 354.