Scalar resonances: scattering and production amplitudes
arXiv:0705.3260 · doi:10.1103/PhysRevD.76.094011
Abstract
Scattering and production amplitudes involving scalar resonances are known, according to Watson's theorem, to share the same phase . We show that, at low energies, the production amplitude is fully determined by the combination of with another phase , which describes intermediate two-meson propagation and is theoretically unambiguous. Our main result is a simple and almost model independent expression, which generalizes the usual -matrix unitarization procedure and is suited to be used in analyses of production data involving scalar resonances.
10 pages, 4 figures. Minor changes, references added, version to appear in Phys. Rev. D