Speaker
Matthew Wysocki
(University of Colorado Boulder)
Description
The production of heavy quarkonia in high-energy nuclear collisions is a problem that is still poorly understood, even without the presence of the quark-gluon plasma. The most common method of calculation is with nuclear-modified parton distribution functions and a break-up cross section for the (pre-J/psi) c-cbar pair passing through the nucleus. Calculations of this nature will be presented (as detailed in arXiv:1011.4534) with different assumptions about the geometric dependence of the nuclear modifications, and the results will be compared to the latest PHENIX d+Au experimental data. It will be demonstrated that no combination of nPDFs and sigma_breakup, regardless of the nPDF parameter set and the assumed geometric dependence, can simultaneously describe the entire rapidity and centrality dependence of J/psi modifications in d+Au collisions at sqrt(s_NN) = 200 GeV. We will also extend the calculations to include a simple model of initial-state parton energy loss, with the same result. We will then compare the results of these calculations with others using coherent J/psi production and gluon saturation at low x. Finally, we will project these calculations to Au+Au collisions at sqrt(s_NN) = 200 GeV, and compare to the latest experimental data for that case.
Author
Matthew Wysocki
(University of Colorado Boulder)