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arXiv · 1001.4709

All-order results for infrared and collinear singularities in massless gauge theories

Lance J. Dixon·Einan Gardi·Lorenzo Magnea
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Abstract

We review recent results concerning the all-order structure of infrared and collinear divergences in massless gauge theory amplitudes. While the exponentiation of these divergences for nonabelian gauge theories has been understood for a long time, in the past couple of years we have begun to unravel the all-order structure of the anomalous dimensions that build up the perturbative exponent. In the large-Nc limit, all infrared and collinear divergences are determined by just three functions; one of them, the cusp anomalous dimension, plays a key role also for non-planar contributions. Indeed, all infrared and collinear divergences of massless gauge theory amplitudes with any number of hard partons may be captured by a surprisingly simple expression constructed as a sum over color dipoles. Potential corrections to this expression, correlating four or more hard partons at three loops or beyond, are tightly constrained and are currently under study.

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Lance J. Dixon, Einan Gardi, Lorenzo Magnea. 2010-01-26. All-order results for infrared and collinear singularities in massless gauge theories. https://arxiv.org/abs/1001.4709

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