Predictions for the diffractive photoproduction of the γ-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(Q2) accuracy, and the large magnitude of the real part of the amplitude. The resultant cross sections are found to agree fairly well with recent preliminary data from ZEUS and HI. 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/ψ-production.
|Original language||English (US)|
|Journal||Journal of High Energy Physics|
|State||Published - Dec 1 1999|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics