Peláez Sagredo, José RamónGómez Nicola, Ángel2023-06-202023-06-2020030-7354-0120-910.1063/1.1570564https://hdl.handle.net/20.500.14352/60911© Amer Inst Physics. International Workshop on Hadron Physics (2. 2002. Coimbra, Portugal). A.G.N and J.R.P wish to thank the organizers of the "2nd International Workshop on Hadron Physics" for their kind invitation and for their efforts to offer us such a pleasant and lively workshop in Coimbra. Work supported by the Spanish CICYT projects, FPA2000-0956, PB98-0782 and BFM2000-1326. J.R.P. acknowledges support from the CICYT-INFN collaboration grant 003P 640.15.We report on our recent progress in the generation of resonant behavior in unitarized meson-meson scattering amplitudes obtained from Chiral Perturbation Theory. These amplitudes provide simultaneously a remarkable description of the resonance region up to 1.2 GeV as well as the low energy region, since they respect the chiral symmetry expansion. By studying the position of the poles in these amplitudes it is possible to determine the mass and width of the associated resonances, as well as to get a hint on possible classification schemes, that could be of interest for the spectroscopy of the scalar sector.engbook parthttp://dx.doi.org/10.1063/1.1570564http://scitation.aip.org/http://arxiv.org/abs/hep-ph/0301049open access51-73Pi-pi-scatteringInverse amplitude methodMulti-quark hadronsOne-loopGev-cK scatteringPhase-shiftDecayLagrangiansParticleFísica-Modelos matemáticosFísica matemática