Diffractive Photoproduction of $\Upsilon$ at HERA
Abstract
Predictions for the diffractive photoproduction of the -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() 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 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 -production.
Cite
@article{arxiv.hep-ph/9812316,
title = {Diffractive Photoproduction of $\Upsilon$ at HERA},
author = {L. L. Frankfurt and M. F. McDermott and M. Strikman},
journal= {arXiv preprint arXiv:hep-ph/9812316},
year = {2010}
}
Comments
13 pages, latex2e, 5 figures, 5 tables. Revised version corrects a bug in the original code, the effect is to reduce the normalization by about 40%. Figures 3-5 updated. Minor modifications and clarifications included in the text in response to referees report. Qualitative conclusions remain unchanged