New insight in global QCD fits using Regge theory

Abstract

In global QCD fits, one has to choose an initial parton distribution at Q^2=Q_0^2. I shall argue that the initial condition choses in usual standard sets is inconsistent with analytic S-matrix theory. I shall show how one can combine these two approaches, leading to a Regge-compatible next-to-leading order global QCD fit. This allows one to extend the parametrisation in the low-Q^2 region. Finally, I shall discuss how it it possible to use the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) equation to obtain information on Regge models at high Q^2.