Transverse-momentum pt correlations on (η, φ) from mean-pt fluctuations in Au–Au collisions at VSNN = 200 GEV

Abstract

We present first measurements of the pseudorapidity and azimuth (η, φ) binsize dependence of event-wise mean transverse-momentum pt fluctuations for Au–Au collisions at VsNN = 200 GeV. We invert that dependence to obtain pt autocorrelations on differences (η , φ ) interpreted to represent velocity/temperature distributions on (η, φ). The general form of the autocorrelations suggests that the basic correlation mechanism is parton fragmentation. The autocorrelations vary rapidly with collision centrality, which suggests that fragmentation is strongly modified by a dissipative