English

Nothing anomalous about two-loop HBCPT: consistency with the LET for spin-dependent Compton scattering

High Energy Physics - Phenomenology 2008-11-26 v2 Nuclear Theory

Abstract

The leading order contributions of processes involving anomalous pion-photon vertices to forward spin-dependent Compton scattering from nucleons are considered in heavy-baryon chiral perturbation theory. These all involve the exchange of three pions between one or two photons and the nucleon, and hence are two-loop processes. We find that the sum of these processes vanishes in the manner predicted by the low energy theorem of Low, Gell-Mann and Goldberger as the photon energy goes to zero. This provides the first consistency test of two-loop HBCPT.

Keywords

Cite

@article{arxiv.hep-ph/9908249,
  title  = {Nothing anomalous about two-loop HBCPT: consistency with the LET for spin-dependent Compton scattering},
  author = {Judith A. McGovern and Michael C. Birse},
  journal= {arXiv preprint arXiv:hep-ph/9908249},
  year   = {2008}
}

Comments

Minor typos corrected. 7 pages RevTeX, 1 eps figure

R2 v1 2026-07-22T14:52:58.399Z