Paper
The Singular Behaviour of QCD Amplitudes at Two-loop Order
Authors
Stefano Catani
Abstract
We discuss the structure of infrared singularities in on-shell QCD amplitudes at two-loop order. We present a general factorization formula that controls all the -poles of the dimensionally regularized amplitudes. The dependence on the regularization scheme is considered and the coefficients of the and poles are explicitly given in the most general case. The remaining single-pole contributions are also explicitly evaluated in the case of amplitudes with a pair.