R-evolving QCD matrix elements

Abstract

© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. MS, combined with dimensional regularization, is one of the most popular and practical renormalization scheme in quantum field theory. One of the drawbacks of this scheme is however that undesired infrared contributions hide in the short-distance calculations and manifest themselves as the so called renormalon ambiguities. We have found a simple way to remove these terms which retains the properties of calculation of MS. The subtraction requires the introduction of a new cutoff scale, R, that controls power divergences. The variation of the final result with R is solved with an appropriate differential equation, very similar to the usual Renormalization Group equations. The evolution so defined is called R-evolution. We illustrate the application to Ellis-Jaffe sum rule. Preprint numbers: MPP-2010-5, MIT-CTP 4114.