The study of non-collectivity by the forward–backward multiplicity correlation function

Abstract

We propose a forward–backward multiplicity correlation function CNFB, which is experimentally accessible, to measure the non-collectivity contribution. It is found that the function is sensitive to both the jet contribution and small number statistics. We point out that the effect of the latter is also involved in the previous studies of the forward–backward elliptic correlation function but was misinterpreted as a contribution from jets. We study the CNFB in Au+Au collision at GeV with a multiphase transport model (AMPT). The result shows that the estimated jet contribution is much smaller than in the previous study due to the finite number statistics which has not been noticed before. The connection between this study and the forward–backward elliptic correlation function is also discussed.