Second-order quantum-chromodynamic effect inJψphotoproduction

Abstract

Second-order quantum-chromodynamics (QCD) contributions are calculated for $\frac{J}{\psi }$ photoproduction. We show that the measurement of the nonforward structure of the cross section $\frac{d\sigma }{\mathrm{dt}}$ at large $-t(\ge 1 \mathrm{Ge}{\mathrm{V}}^2)$ could be an excellent test for QCD.