Light-by-light scattering sum rules constraining meson transition form factors
Abstract
Relating the forward light-by-light scattering to energy weighted integrals of the \gamma* \gamma -fusion cross sections, with one real photon (\gamma) and one virtual photon (\gamma*), we find two new exact super-convergence relations. They complement the known super-convergence relation based on the extension of the GDH sum rule to the light-light system. We also find a set of sum rules for the low-energy photon-photon interaction. All of the new relations are verified here exactly at leading order in scalar and spinor QED. The super-convergence relations, applied to the \gamma* \gamma -production of mesons, lead to intricate relations between the \gamma \gamma -decay widths or the \gamma* \gamma -transition form factors for (pseudo-) scalar, axial-vector and tensor mesons. We discuss the phenomenological implications of these results for mesons in both the light-quark sector and the charm-quark sector.
Cite
@article{arxiv.1204.0740,
title = {Light-by-light scattering sum rules constraining meson transition form factors},
author = {Vladimir Pascalutsa and Vladyslav Pauk and Marc Vanderhaeghen},
journal= {arXiv preprint arXiv:1204.0740},
year = {2013}
}
Comments
32 pages, 7 figures