The soft current describes the factorization behavior of quantum chromodynamics (QCD) scattering amplitudes in the limit of vanishing energy of one of the external partons. It is process-independent and can be expanded in a perturbative series in the coupling constant. To all orders in the dimensional regularization parameter, we compute the two-loop correction to the soft current for processes involving two hard partons.
@article{arxiv.1309.4393,
title = {The two-loop soft current in dimensional regularization},
author = {Claude Duhr and Thomas Gehrmann},
journal= {arXiv preprint arXiv:1309.4393},
year = {2015}
}