A model for the gluonic Pomeron and its unitarization

Abstract

First, an approach for the gluonic Pomeron, based on dispersion theory (N/D method), is presented. The input is the O( α s ) gauge invariant set of QCD graphs for gluon-gluon scattering. The resulting amplitude, analytically continued in complex angular momentum, leads to a fixed branch point with an intercept similar to that of the Lipatov Pomeron. Next, the above amplitude is unitarized via eikonal methods amounting to its iteraction along the s-channel. A specific model is considered, and the energy dependence of the elastic, total and diffraction dissociation cross sections and of the slope parameter is obtained in accord with experiment.