Two-loop helicity amplitudes for fermion-fermion scattering
Abstract
Description
We discuss the calculation of two-loop helicity amplitudes for quark-quark scattering in QCD and four-gluino scattering in N=1 supersymmetric Yang-Mills theory. We study the dependence of the results on different variants of dimensional regularization. In particular, we consider the 't Hooft-Veltman and four-dimensional helicity (FDH) schemes. We also discuss ambiguities in continuing the Dirac algebra to D dimensions. For the four-gluino case, once the infrared divergent part of the amplitude is subtracted, the finite remainder is free of these ambiguities.
Presented at 7th DESY Workshop on Elementary Particle Theory: Loops and Legs in Quantum Field Theory, Zinnowitz, Germany, 25-30 Apr 2004
Presented at 7th DESY Workshop on Elementary Particle Theory: Loops and Legs in Quantum Field Theory, Zinnowitz, Germany, 25-30 Apr 2004