Rescattering effects in eta {\to} 3pi decays
Abstract
The isospin-breaking decay eta {\to} 3pi is an ideal tool to extract information on light quark mass ratios from experiment. For a precise determination, however, a detailed description of the Dalitz plot distribution is necessary. In that respect, in particular the slope parameter alpha of the neutral decay channel causes some concern, since the one-loop prediction from chiral perturbation theory misses the experimental value substantially. We use the modified non-relativistic effective field-theory, a dedicated framework to analyze final-state interactions beyond one loop including isospin-breaking corrections, to extract charged and neutral Dalitz plot parameters. Matching to chiral perturbation theory at next-to-leading order, we find alpha = -0.025 +- 0.005, in marginal agreement with experimental findings. We derive a relation between charged and neutral decay parameters that points towards a significant tension between the most recent KLOE measurements of these observables.
Cite
@article{arxiv.1010.3946,
title = {Rescattering effects in eta {\to} 3pi decays},
author = {Sebastian P. Schneider and Bastian Kubis and Christoph Ditsche},
journal= {arXiv preprint arXiv:1010.3946},
year = {2011}
}
Comments
48 pages, 5 figures; appendix C added, version published in JHEP