Chiral Breit-Wigner

Abstract

Chiral symmetry and unitarization are combined into generalized Breit-Wigner expressions describing scalar resonances, which contain free parameters and allow flexible descriptions of masses, widths and pole positions. This theoretical tool is especially designed to be used in analyses of low-energy data.Comment: Talk given at the XI International Conference on Hadron Spectroscopy, Rio de Janeiro, Brazil, August 200