[Submitted on 11 May 2017] (cross-list from hep-ph)
Dispersion relations for
Tobias Isken🇩🇪 · Bastian Kubis🇩🇪 · Sebastian P. Schneider🇩🇪 · Peter Stoffer🇩🇪
We present a dispersive analysis of the decay amplitude for that is based on the fundamental principles of analyticity and unitarity. In this framework, final-state interactions are fully taken into account. Our dispersive representation relies only on input for the and scattering phase shifts. Isospin symmetry allows us to describe both the charged and neutral decay channel in terms of the same function. The dispersion relation contains subtraction constants that cannot be fixed by unitarity. We determine these parameters by a fit to Dalitz-plot data from the VES and BES-III experiments. We study the prediction of a low-energy theorem and compare the dispersive fit to variants of chiral perturbation theory.
- Comments:
- 22 pages, 10 figures; v2: added footnote, version published in EPJC
- Subjects:
- High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
- arXiv:
- 1705.04339 [pdf]