Peláez Sagredo, José RamónYnduráin, F.J.2023-06-202023-06-2020050-7354-0241-810.1063/1.1920932https://hdl.handle.net/20.500.14352/53486©2005 American Institute of Physics. ISSN: 0094-243X Conference on Quark Confinement and the Hadron Spectrum (6. 2004. Helsinki, Finlandia). F.J. Ynduráin is grateful to the organizing committee for the opprtunity to talk at the meeting and for financial support.We have evaluated forward dispersion relations for scattering amplitudes that follow from direct fits to several sets of ππ scattering experiments, together with the precise K decay results, and high to energy data. We find that some of the most commonly used experimental sets, as well as some recent theoretical analyses based on Roy equations, do not satisfy these constraints by several standard deviations. Finally, we provide a consistent ππ amplitude by improving a global fit to data with these dispersion relations.engbook parthttp://dx.doi.org/10.1063/1.1920932http://scitation.aip.orgopen access51-73Phase-shift analysisGev-cParametersAmplitudesπ&πFísica-Modelos matemáticosFísica matemática