Paper detail

Interplay of correlations and fluctuations in Au+Au collisions at RHIC

Dynamic fluctuations in the local density of non-identified hadron tracks reconstructed in the STAR TPC are studied using the discrete wavelet transform power spectrum technique which involves mixed event reference sample comparison. The two-dimensional event-by-event analysis is performed in pseudo-rapidity (eta) and azimuthal angle (phi). HIJING simulations indicate that jets and mini-jets result in signals, visible without high pT selection, when the dynamic texture analysis is applied. Scanning a broad range of event multiplicities, we study the dependence of the signals on the initial conditions. Event structures are studied separately with positive and negative tracks, as well as both charges. A change of regime is observed in AuAu collisions at sqrt(S_NN}=130 GeV as event multiplicity is increased: a long range eta correlation (or suppressed fluctuation vis-a-vis mixed events) is seen in same charge data. This effect is qualitatively similar to one of the predicted manifestations of the Color Glass Condensate.