Quark-antiquark contribution to the hadroproduction ofψin the color-singlet model

We consider the contribution to $\psi$ hadroproduction due to the elementary subprocess $q\overline{q}\to \psi \mathrm{GG}$. The color-singlet nature and observed spin-parity of the $\psi$ are incorporated and the normalization of the cross section is predicted by the $\psi$ wave function at the origin as measured in the leptonic $\psi$ decay. We expect this process to dominate the difference in $\psi$ production from particle versus antiparticle beams. The energy dependence of $\psi$ production as well as distributions in $x_F$ and $P_T$ are predicted.