Forward-backward multiplicity correlations in pp, p-barp and Au+Au collisions at RHIC energy

The strength of charged particle forward-backward multiplicity correlation in p-barp and pp collisions at √(s)=200GeV is studied by the PYTHIA model and compared with the UA5 and STAR data correspondingly. It turns out that a factor of 3-4 apparent discrepancy between UA5 and STAR data can be attributed to the differences in detector acceptance and observing bin width. We have also studied the centrality bin size dependence of the correlation strength in 0-10 to 0-5 and to 5% most central Au+Au collisions at √(sNN)=200GeV with the PACIAE model. It turns out that the correlation strength decreases with decreasing centrality bin size monotonously.