Introduction to low x physics and diffraction

Abstract

The basic concepts relevant for the theoretical description of deep inelastic scattering within the QCD improved parton model are introduced. Recent developments in low $x$ DIS and in deep inelastic diffraction are briefly summarised. This includes discussion of the BFKL dynamics including the subleading effects and of the saturation model. The dedicated measurements, which probe the QCD pomeron are also discussed.

10 pages, introductory talk presented at the 30th International Symposium on Multiparticle Dynamics (ISMD 2000), 9-15 Oct 2000, Tihany, Lake Balaton, Hungary