J/psi Production: Tevatron and Fixed-Target Collisions

Abstract

In this talk I show the results of a fit of the NRQCD matrix elements to the CDF data for direct $J/\psi$ production, by including the radiative corrections to the colour-singlet channel and the effect of the $k_T$-smearing. Furthermore I perform the NLO NRQCD analysis of $J/\psi$ production in fixed-target proton-nucleon collisions and I fit the colour-octet matrix elements to the available experimental data. The results are compared to the Tevatron ones.

Comments: 6 pages, 3 figures. Talk given at the QCD99 Euroconference, Montpellier, France, July 1999