RT Book, Section T1 Poles of light resonances from unitarized Chiralperturbation Theory and their large N_c behavior A1 Peláez Sagredo, José Ramón AB We have recently completed the one loop calculation of meson-meson scattering within Chiral Perturbation Theory. Once unitarized, these amplitudes provide simultaneously a remarkable description of the resonance region up to 1.2 GeV as well as the low energy region, respecting the chiral symmetry expansion. The position of the poles in these amplitudes is related to the mass and width of the associated resonances that are generated without being explicitly included in the Lagrangian. The spectroscopic nature of these states can then be deduced by studying the behavior of these poles, through the N_c dependence of the Chiral Perturbation Theory parameters, which can be obtained from QCD in the large N_c limit. PB Amer Inst Physics SN 0-7354-0161-6 YR 2003 FD 2003 LK https://hdl.handle.net/20.500.14352/60961 UL https://hdl.handle.net/20.500.14352/60961 LA eng NO ©Amer Inst Physics.Annual Montreal-Rochester-Syracuse-Toronto Conference on High Energy Physics (MRST 2003) (15. 2003. Siracusa,Nueva York).First of all, I wish to thank the MRST’03 organizers, and specially A. Fariborz, for their kind invitation and for their efforts to offer us such a pleasant and lively workshop in Syracuse. In addition, I wish to thank A. Gómez Nicola for his comments and his careful reading of the manuscript. I also thank A. Andrianov, E. Espriu, F. Kleefeld for encouraging me to look for the large Nc behavior of the poles, as well as R. Jaffe for his comments on the large Nc behavior of multiquark hadrons. Work supported by a Marie Curie fellowship, contract MCFI-2001-01155, the Spanish CICYT projects, FPA2000-0956, PB98-0782 and BFM2000-1326, the CICYT-INFN collaboration grant 003P 640.15, and the E.U. EURIDICE network contract no. HPRN-CT-2002-00311. NO Marie Curie fellowship NO Spanish CICYT NO CICYT-INFN NO E.U. EURIDICE network DS Docta Complutense RD 4 abr 2025