The Three-Loop Splitting Functions in QCD

Abstract

We have computed the next-to-next-to-leading-order (NNLO) contributions to the evolution of unpolarized parton distributions in perturbative QCD. In this talk, we briefly recall why this huge computation was necessary and outline how it was performed. We then illustrate the structure of the results and discuss their end-point limits which include the three-loop cusp anomalous dimensions of the Wilson lines. Finally the numerical impact of the new contributions is illustrated.

18 pages, LaTeX, 6 figures. Presented by A.V. at DIS 2004, Strbske Pleso (Slovakia), April 2004 and QCD 04, Montpellier (France), July 2004. To appear in the proceedings of DIS 2004 and, substantially shortened, of QCD 04