Diffractive Photoproduction of $\ups$ at HERA
Abstract
Predictions for the diffractive photoproduction of the $\ups$-family at HERA energies, within the framework of the analysis by Frankfurt, Koepf and Strikman, are presented. Two novel effects lead to a significant enhancement of the original calculation: the non-diagonal (or skewed) kinematics, calculated to leading-log(Q^2) accuracy, and the large magnitude of the real part of the amplitude. The resultant cross sections are found to agree with recent preliminary data from ZEUS and H1. A strong correlation between the mass of the diffractively produced state and the energy dependence of the cross section is found. In particular, a considerably stronger rise in energy is predicted than that found in $J/\psi$-production.Keywords
All Related Versions
This publication has 0 references indexed in Scilit: