Abstract
The resummation of soft-gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions. We compute this matrix directly for arbitrary massless processes for the first time at two loops. Using color-generator notation, we show that it is proportional to the one-loop matrix. This result reproduces all pole terms in dimensional regularization of the explicit calculations of massless amplitudes in the literature, and it predicts all poles at next-to-next-to-leading order in any process that has been computed at next-to-leading order. The proportionality of the one- and two-loop matrices makes possible the resummation in closed form of the next-to-next-to-leading logarithms and poles in dimensional regularization for the processes.
- Received 26 June 2006
DOI:https://doi.org/10.1103/PhysRevLett.97.072001
©2006 American Physical Society