Perturbative versus Non-perturbative QFT -- Lessons from the O(3) NLS Model
arXiv:hep-th/9604161 · doi:10.1016/0370-2693(96)00906-9
Abstract
The two-point functions of the energy-momentum tensor and the Noether current are used to probe the O(3) nonlinear sigma model in an energy range below 10^4 in units of the mass gap . We argue that the form factor approach, with the form factor series trunctated at the 6-particle level, provides an almost exact solution of the model in this energy range. The onset of the (2-loop) perturbative regime is found to occur only at energies around .
13 pages LaTex, 4 PostScript figures; version published in Physics Letters B