Bose-Einstein correlations in perturbative QCD: v_n dependence on multiplicity

摘要

In this paper we study the dependence of Bose-Einstein correlations on the multiplicity of an event. We find that events with large multiplicity stem from the production of several-parton showers, while the additional production of small multiplicity in the central rapidity region (central diffraction) gives a negligible contribution due to emission of soft gluons, which leads to the Sudakov suppression of the exclusive production of two-gluon jets. Hence, the Bose-Einstein correlation is the main source of the azimuthal angle correlations which generate v_n with odd and even n.We find that without this suppression, the measurement of an event with given multiplicity yields v_(n,n) < 0 for odd n. It appears that in hadronnucleus and nucleus-nucleus collisions, the Bose-Einstein correlations do not depend on multiplicity, while for hadron-hadron scattering such dependence can be considerable. We propose a simple Kharzeev-Levin- Nardi type model to describe the dependence of azimuthal angle correlations on the centrality of the event in ion-ion collisions.