Polarized J/ψ production in deep inelastic scattering at DESY HERA -: art. no. 034017

We perform a calculation on the polarization of J/psi production in deep inelastic scattering in the DESY HERA energy range. For the inclusive production distributions, we find that the color-singlet contributions are consistent with the experimental data in the major region of z (z > 0.4). Only in low z regions are there some hints of the need for the color-octet contributions to describe the experimental data. For the polarization of J/psi in deep inelastic scattering processes, we find the parameter a changes with Q(2). Especially at higher Q(2), the difference in a between color-singlet and color-octet contributions becomes more distinctive. In the two regions of lower and larger z, the polarization parameter a has different features. These properties can provide important information on the polarization mechanism for J/psi production.