Quarkonia production in pp, p(d)A and AA Collisions

Quarkonia (J/ψ,ψ′,ϒ) production provides a sensitive probe of gluon distributions and their modification in nuclei; and is a leading probe of the hotdense (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.