The effect of many sources on the genuine multiparticle correlations

Abstract We report on a study aimed to explore the dependence of the genuine multiparticle correlations on the number of sources when the influence of other possible factors during multi-hadron production is avoided. The analysis utilised the normalised cumulants calculated in three-dimensional phase space of the reaction e + e − →Z 0 →hadrons using a large Monte Carlo sample. The multi-sources reactions were simulated by overlaying a few independent single e + e − annihilation events. It was found that as the number of sources S increases, the cumulants do not change significantly their structure, but those of an order q >2 decrease fast in their magnitude. This reduction in the one-dimensional rapidity cumulants can be understood in terms of combinatorial considerations of source mixing which dilutes the correlations by a factor of about 1/ S q −1 . The diminishing of the genuine correlations is consistent with recent cumulant measurements in hadron and nucleus induced reactions and should also be relevant to other dynamical correlations like the Bose–Einstein one, in e + e − →W + W − →hadrons and in nucleus–nucleus reactions.