Diffusion into infra-red and unitarization of the BFKL pomeron

Abstract

The BFKL pomeron in perturbative QCD is plagued by the lack of unitarity and diffusion into the infra-red region of gluon virtualities. These two problems are intimately related. We perform numerical studies of the evolution equation proposed by Balitsky and Kovchegov which unitarizes the BFKL pomeron. We show how diffusion into the infra-red region is suppressed due to the emergence of a saturation scale and scaling behaviour. We study universality of this phenomenon as well as its dependence on subleading corrections to the BFKL pomeron such as the running coupling and kinematic constraint. These corrections are very important for phenomenological applications.