The BFKL and GLDAP regimes for the perturbative QCD pomeron

Abstract

The $S$-matrix of diffractive scattering is diagonalized in terms of the colour dipole-dipole cross section. Recently, we have shown that the dipole cross section satisfies the generalized BFKL equation. In this paper we discuss the spectrum and solutions of our generalized BFKL equation with allowance for the finite gluon correlation radius $R_{c}$. The latter is introduced in the gauge invariant manner. We present estimates of the intercept of the pomeron and find the asymptotic form of the dipole cross section. We consider the difference between the BFKL and GLDAP evolutions and conclude that the GLDAP evolution remains a viable description of deep inelastic scattering well beyond the kinematical range of the HERA experiments. We suggest methods of measuring the pomeron intercept in the HERA experiments.