出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We investigate the centrality dependence of the pT -correlations in the event-by-event analysis of
relativistic heavy-ion collisions at RHIC made recently by the PHENIX and STAR Collaborations.
We notice that s 2
dyn scales to a very good accuracy with the inverse number of the produced
particles, n. This scaling can be naturally explained by formation of clusters. We discuss the
nature of clusters and provide numerical estimates of correlations coming from resonance decays,
which are tiny, and a model where particle are emitted from local thermalized sources moving
at the same collective velocity. This "lumped cluster. model can explain the data when on the
average 6-15 particles are contained in a cluster. We also point out simple relations of the popular
correlation measures to the covariance, which arise under the assumptions (well holding at
RHIC) that the distributions are sharply peaked in n and that the dynamical compared to statistical
uctuations are small.
