Multi-loop Amplitudes and Resummation
Abstract
We explore the relation between resummation and explicit multi-loop calculations for QCD hard-scattering amplitudes. We describe how the factorization properties of amplitudes lead to the exponentiation of double and single poles at each order of perturbation theory. For these amplitudes, previously-observed relations between single and double poles in different 2 to 2 processes can now be interpreted in terms of universal functions associated with external partons and process-dependent anomalous dimensions that describe coherent soft radiation. Catani's proposal for multiple poles in dimensionally-continued amplitudes emerges naturally.
Cite
@article{arxiv.hep-ph/0210130,
title = {Multi-loop Amplitudes and Resummation},
author = {George Sterman and Maria E. Tejeda-Yeomans},
journal= {arXiv preprint arXiv:hep-ph/0210130},
year = {2014}
}
Comments
14 pages, LateX2e using elsart.cls (included). Typographical errors corrected and expansion in renormalized coupling clarified. Thanks added to Z. Bern and L. Dixon for critical readings of the original version