QED contribution to the production of J/ψ plus c(c)over-bar + X at the Tevatron and LHC

We calculate alpha(2)alpha(2)(s) order QED contribution to J/psi production in the pp((p) over bar) -> J/psi + c (c) over bar color-singlet process at the Tevatron and LHC in the framework of nonrelativistic QCD. The contribution of the interference between the alpha 2 alpha(2)(s) QED and alpha(4)(s) QCD is also taken into account. The J/psi production associated with a charm-quark pair could be a measurable signal at hadron collider experiment. Our calculations show that by including the QED contribution, the p(t) distribution is enhanced by a factor of 1.5 (1.9) at the Tevatron (LHC) at p(t) 50(100) GeV. In addition, the polarization of J/psi turns from unpolarized in all regions to increasingly transverse when pt becomes larger.