On heavy-quarkonia suppression by final-state multiple scatterings in most central Au + Au collisions at RHIC

We study heavy-quarkonia suppression under final-state multiple scatterings in most central Au+Au collisions at RHIC energy. We first calculate the survival probability of a heavy quarkonium under multiple scattering in Bjorken's expanding QGP at large Nc. Then, we calculate the rapidity dependence of the nuclear modification factor RAA for heavy-quarkonia production by considering final-state multiple scatterings in most central Au+Au collisions in a simplified model. In our formula a constant P0 is also introduced to estimate the possible cold nuclear effects. By fitting the data for J/Ψ production in most central Au+Au collisions at at RHIC, we find that the transportation coefficient , and, accordingly, the energy density at τ0 is ϵ0≃(1.39–5.62) GeV/fm3 in perturbative thermal QCD. A better understanding of cold nuclear effects is essential for us to get a more accurate analysis. The small values of the transportation coefficient in our estimate are in sharp contrast with those obtained by the analysis of high-pT hadron spectra in Eskola et al. (2005) [31].