The lowest resonance in QCD from low--energy data
High Energy Physics - Phenomenology
2015-06-18 v1
Abstract
We show that a generalization of Chiral Perturbation Theory, including a perturbative singlet scalar field, converges faster towards the physical value of sensible low--energy observables. The physical mass and width of the scalar particle are obtained through a simultaneous analysis of the pion radius and the gamma gamma -> pi^0 pi^0 cross-section. Both values are statistically consistent with the ones obtained by using Roy equations in pi-pi scattering. In addition we find indications that the photon-photon-singlet coupling is quite small.
Cite
@article{arxiv.1402.2649,
title = {The lowest resonance in QCD from low--energy data},
author = {L. Ametller and P. Talavera},
journal= {arXiv preprint arXiv:1402.2649},
year = {2015}
}
Comments
pdfLatex 15 pages, 3 figures