Oller, JAOset, E.Peláez Sagredo, José Ramón2023-06-202023-06-201999-04-010556-282110.1103/PhysRevD.59.074001https://hdl.handle.net/20.500.14352/60093©1999 The American Physical Society. We are grateful to A. Dobado for discussions concerning the tadpole contributions and for his careful reading of the manuscript. Two of us, J.A.O and E.O., would like to thank the kind hospitality of the Complutense University of Madrid. J.R.P. wishes to thank the hospitality of the University of Valencia and the SLAC Theory Group, as well as M. Suzuki for his comments on the octet f. This work was partially supported by DGICYT under contracts PB96-0753 and AEN93-0776. J.A.O. and J.R.P. acknowledge financial support from the Generalitat Valenciana and the Ministerio de Educación y Cultura, respectively.A nonperturbative method which combines constraints from chiral symmetry breaking and coupled channel unitarity is used to describe the meson-meson interaction up to about 1.2 GeV. The approach uses the O(p_2) and O(p^4) chiral Lagrangians. The seven free parameters of the O(p^4) Lagrangian are fitted to the data. The results are in good agreement with a vast amount of experimental analyses. The amplitudes develop poles in the complex plane corresponding to the f_0, a_0, ρ, K^*, φ, δ and ĸ resonances, the latter two being very broad. The total and partial decay widths of the resonances are also well reproduced. Further extensions and applications of this chiral nonperturbative scheme are also discussed. [S0556-2821(99)05003-1].engjournal articlehttp://dx.doi.org/10.1103/PhysRevD.59.074001http://journals.aps.orgopen access51-73Symmetry-breaking sectorCoupled-channel analysisPerturbation-theoryPi-scatteringScalar mesonsPhase-shiftGev-cDispersionF(0)(980)A(0)(980)Física-Modelos matemáticosFísica matemática