# Cusp anomalous dimension in QCD

What is the "cusp anomalous dimension", starting from the basics? I came across this term while reading some QCD papers.

-
Better to ask what it is than to ask where to read about it. People will provide references if they need to. I'm editing accordingly. –  David Z Dec 2 '11 at 9:40
@David: I looked up the reference, as the original question asked. I hope this is still useful. –  Ron Maimon Dec 2 '11 at 11:38
Yeah, of course. If you don't know what something is but you can find a reference for it, that's generally a fine answer to a question asking what it is. –  David Z Dec 2 '11 at 15:16
I think it's best as a comment, since it no longer answers the question. It is described here: arxiv.org/abs/hep-ph/9210281 . This is referenced by: arxiv.org/abs/hep-th/0204051 , which describes the string theory point of view about this. –  Ron Maimon Dec 2 '11 at 18:25