Soft Collinear Degeneracies in an Asymptotically Free Theory
arXiv:1008.3949
Abstract
In asymptotically free theories with collinear divergences it is sometimes claimed that these divergences cancel if one sums over initial and final state degenerate cross-sections and uses an off-shell renormalisation scheme. We show for scalar $Ï^3$ theory in six dimensions that there are further classes of soft collinear divergences and that they do not cancel. Furthermore, they yield a non-convergent series of terms at a fixed order of perturbation theory. Similar effects in gauge theories are also summarised.
10 pages with embedded figures in LaTeX