Quarkonia production at RHIC

Quarkonia (J/ψ, ψ', ) production provides a sensitive probe of gluon distributions and their modification in nuclei, and is a leading probe of the hot-dense (deconfined) matter created in high-energy collisions of heavy ions. I will discuss our current understanding of the modification of gluon distributions in nuclei and other cold-nuclear-matter effects in the context of recent p–p and p(d)–A quarkonia measurements. Then I will review the latest results for nucleus–nucleus collisions from RHIC, and together with the baseline results from d–A and p–p collisions, discuss several alternative explanations for the observed suppressions and future prospects for distinguishing these different pictures.