Solving Renormalization Group Equations by Recursion Relations

Abstract

Renormalization Group Equations in integro-differential form describing the evolution of cascades or resumming logarithmic scaling violations have been known in quantum field theory for a long time. These equations have been traditionally solved by turning to Mellin moments, since in this space they become algebraic. x-space solutions are less known, but special asymptotic expansions exists which allow a fast numerical implementation of these equations. We illustrate how the equations can be solved using recursion relations in the next-to-leading order approximation.

8 pages, 2 Figures, Presented at the Intl. Workshop ``Nonlinear Physics: Theory and Experiment II'', Gallipoli, Lecce, Italy, June 28 - July 4, 2002