J/Psi production in direct and resolved gamma gamma collisions

Abstract

The production of J/Psi mesons in gamma gamma collisions allows for a test of factorization in color-octet processes as predicted by NRQCD and observed at the Tevatron. We calculate the cross sections for J/Psi production with direct and resolved photons, including also the feed-down from chi_{cJ} and Psi' decays. Our NRQCD predictions are nicely confirmed by recent data from the DELPHI collaboration at CERN LEP2.

Comments: Talk presented at the RADCOR/LL 2002 conference. 5 pages, 3 postscript figures