Color Octet Contribution to J/psi Photoproduction Asymmetries

Abstract

We investigate $J/\psi$ photoproduction asymmetries in the framework of the NRQCD factorization approach. It is shown that the color octet contribution leads to large uncertainties in the predicted asymmetries which rules out the possibility to precisely measure the gluon polarization in the nucleon through this final state. For small values of the color octet parameters being compatible with $J/\psi$ photoproduction data it appears possible that a measurement of $J/\psi$ asymmetries could provide a new test for the NRQCD factorization approach, on one hand, or a measurement of the polarized gluon distribution from low inelasticity events $(z<0.7)$, on the other

10 pages, LaTeX, with 6 eps figs included with epsfig.sty

References in corpus (7)

• Inelastic photoproduction of polarised $J/\psi$
• Charmonium Production in Deep Inelastic Scattering at HERA
• Quarkonium Production through Hard Comover Scattering
• Inelastic $J/\psi$ production in polarized photon-hadron collisions
• Quarkonium Polarization in Non-relativistic QCD and the Quark-Gluon Plasma
• Double Spin Asymmetries in P-wave Charmonium Hadroproduction
• ${\rm Y}$ Polarization at HERA-$B$

Cited by in corpus (3)

• Theory of hard photoproduction
• Charmonium production in polarized high-energy collisions
• Electroproduction of psi' and polarized gluon distribution in a proton