We use the known soft and collinear limits of tree- and one-loop scattering amplitudes -- computed over a decade ago -- to explicitly construct a subtraction scheme for next-to-next-to-leading order (NNLO) computations. Our approach combines partitioning of the final-state phase space together with the technique of sector decomposition, following recent suggestions in Ref. [1]. We apply this scheme to a toy example: the NNLO QED corrections to the decay of the Z boson to a pair of massless leptons. We argue that the main features of this subtraction scheme remain valid for computations of processes of arbitrary complexity with NNLO accuracy.
@article{arxiv.1111.7041,
title = {A subtraction scheme for NNLO computations},
author = {Radja Boughezal and Kirill Melnikov and Frank Petriello},
journal= {arXiv preprint arXiv:1111.7041},
year = {2015}
}