Numerical Evaluation of One-Loop Diagrams Near Exceptional Momentum Configurations

Abstract

One problem which plagues the numerical evaluation of one-loop Feynman diagrams using recursive integration by part relations is a numerical instability near exceptional momentum configurations. In this contribution we will discuss a generic solution to this problem. As an example we consider the case of forward light-by-light scattering.Comment: 5 pages, 5 figures, Talk given at the 7th DESY Workshop on Elementary Particle Theory, Loops and Legs in Quantum Field Theory, Zinnowitz 200