DIRECT PHOTOPRODUCTION OF JETS IN THE KT-FACTORIZATION PRESCRIPTION

We study the cross section for dijet production via direct photons, as seen at the HERA collider. Rather than assuming the standard factoris ation formula for the cross section (where the incoming partons are as sumed to be on-shell), we use the k(T)-factorisation formula. This for malism ought to be more appopriated for jet production in regions wher e the cross section is sensitive to the small-x parton distribution fu nctions. We study the rapidity distribution, the azimuthal angular dis tribution and the p(T) distribution of the jets and compare with the t raditional approach. Our calculations reveal a breakdown of the tradit ional approach as one moves into the regime of small x.