Analysis of charmonium production at fixed-target experiments in the NRQCD approach

F. Maltoni, J. Spengler, M. Bargiotti, A. Bertin, M. Bruschi, S. De Castro, L. Fabbri, P. Faccioli, B. Giacobbe, F. Grimaldi, I. Massa, M. Piccinini, N. Semprini-Cesari, R. Spighi, M. Villa, A. Vitale, A. Zoccoli

Published 2006-01-25, updated 2006-02-13Version 2

We present an analysis of the existing data on charmonium hadro-production based on non-relativistic QCD (NRQCD) calculations at the next-to-leading order (NLO). All the data on J/psi and psi' production in fixed-target experiments and on pp collisions at low energy are included. We find that the amount of color octet contribution needed to describe the data is about 1/10 of that found at the Tevatron.