In-medium formation of quarkonium

Abstract

We confront preliminary RHIC data on J/ψ production in nuclear interactions with expectations which follow in scenarios involving charm quark recombination in a region of colour deconfinement. The focus is on transverse momentum and rapidity spectra of the J/ψ, which carry a memory of the spectra of the charm quarks. In such a scenario, one predicts that both spectra will be narrower than those expected without recombination. Preliminary results for the transverse momentum spectra point towards a preference for the recombination picture, while the rapidity spectra do not exhibit any narrowing within present large uncertainties. We present new calculations in the recombination model for the centrality behaviour of these signals, which map out the necessary experimental precision required for a definitive test.