J/psi, psi' and Upsilon Production at Hadron Colliders: a review

We give an overview of the present status of knowledge of the production of J/psi, psi' and Upsilon in high-energy hadron collisions. We first present two early models, namely the Colour-Singlet Model (CSM) and the Colour-Evaporation Model (CEM). The first is the natural application of pQCD to quarkonium production and has been shown to fail dramatically to describe data, the second is its phenomenological counterpart and was introduced in the spirit of the quark-hadron duality in the late seventies. Then, we expose the most recent experimental measurements of J/psi, psi' and Upsilon prompt and direct production at nonzero p_T from two high-energy hadron colliders, the Tevatron and RHIC. In a third part, we review six contemporary models describing J/psi, psi' and Upsilon production at nonzero p_T.