Energy dependence of diffractive production at HERA Original Research Article

Intrigued by the unexpected recent results from HERA, that the ratio σdiff/σtot is only weakly dependent on energy, we have attempted to reproduce this result within the framework of perturbative QCD. To this end we generalize the Kovchegov–McLerran formula for the ratio using Glauber–Mueller approach for shadowing corrections and AGK cutting rules. We investigate several phenomenological approaches and also compare with the successful Golec-Biernat–Wüsthoff model. We have not managed to reproduce the data, and conclude that, apparently, there are soft nonperturbative contributions present at short distances which should be included.