The Two-loop Anomalous Dimension Matrix for Soft Gluon Exchange

Aybat, S. Mert; Dixon, Lance J.; Sterman, George

The Two-loop Anomalous Dimension Matrix for Soft Gluon Exchange

Authors

Aybat, S. Mert

Dixon, Lance J.

Sterman, George

Description

The resummation of soft gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions. We compute this matrix directly for arbitrary 2 to n 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 2 to 2 amplitudes in the literature, and it predicts all poles at next-to-next-to-leading order in any 2 to n 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 2 to n processes.
5 pages, 1 figure, revtex