Paper
Single soft gluon emission at two loops
Authors
Ye Li, Hua Xing Zhu
Abstract
We study the single soft-gluon current at two loops with two energetic partons in massless perturbative QCD, which describes, for example, the soft limit of the two-loop amplitude for . The results are presented as Laurent expansions in in spacetime dimension. We calculate the expansion to order analytically, which is a necessary ingredient for Higgs production at hadron colliders at next-to-next-to-next-to-leading order in the soft-virtual approximation. We also give two-loop results of the single soft-gluon current in Super-Yang-Mills theory, and find that it has uniform transcendentality. By iteration relation of splitting amplitudes, our calculations can determine the three-loop single soft-gluon current to order in Super-Yang-Mills theory in the limit of large .