Color Evaporation Description of Inelastic Photo-Production of J/ψat HERA

Abstract

The H1 Collaboration recently reported a new analysis on the inelastic photo- production of J/ψmesons at DESY HERA ep collider. We show that these new experimental results are well described by the Color Evaporation Model for quarkonium production. Moreover, this new data requires the introduction of resolved photon contributions in order to explain the results on small charmonium energy fraction, indicating that colored c \bar{c} pairs also contribute to the process.

2-column, six pages, Revtex4, uses epsfig.sty, 7 postscript figures