Low-Energy Photon-Photon Collisions to Two-Loop Order
High Energy Physics - Phenomenology
2011-07-19 v1
Abstract
We evaluate the amplitude for to two loops in chiral perturbation theory. The three new counterterms which enter at this order in the low-energy expansion are estimated with resonance saturation. We find that the cross section agrees rather well with the available data and with dispersion theoretic calculations even substantially above threshold. Numerical results for the Compton cross section and for the neutral pion polarizabilities are also given to two-loop accuracy.
Cite
@article{arxiv.hep-ph/9401206,
title = {Low-Energy Photon-Photon Collisions to Two-Loop Order},
author = {S. Bellucci and J. Gasser and M. E. Sainio},
journal= {arXiv preprint arXiv:hep-ph/9401206},
year = {2011}
}
Comments
48 pages, LaTex, 11 figs. (figures not included; available upon request from sainio@finuhcb.bitnet),BUTP-93/18,LNF-93/077(P),PSI-PR-93-17