Four-Loop Tadpoles: Applications in QCD

Abstract

Recent applications of single-scale four-loop tadpoles are briefly reviewed. An algorithm for the evaluation of current correlators based on differential equations is described and applied to obtain high moments of the vacuum polarization function at O(alphas^2) as a preparation of O(alphas^3) calculations.Comment: 5 pages, 1 figure, to appear in the proceedings of the 8th DESY Workshop on Elementary Particle Theory, Loops and Legs in Quantum Field Theory, April 23-28, 2006, Eisenach, German