Dobado González, AntonioPeláez Sagredo, José Ramón2023-06-202023-06-202002-04-011. S. Weinberg, Physica A 96, 327 (1979); J. Gasser and H. Leutwyler, Ann. Phys. (N.Y.) 158, 142 (1984); J. Gasser and H. Leutwyler, Nucl. Phys. B250, 465 (1985); B250, 517 (1985); B250, 539 (1985). 2. H. Leutwyler, hep-ph/0008124; A. Dobado, A. Gómez-Nicola, A.L. Maroto, and J.R. Peláez, Effective Lagrangians for the Standard Model, Texts and Monographs in Physics (Springer-ag, Berlin, 1997); A. Pich, Rep. Prog. Phys. 58, 563 (1995); U.G. Meißner, ibid. 56, 903 (1993). 3. G. Ecker et al., Nucl. Phys. B321, 311 (1989). 4. J.F. Donoghue et al., Phys. Rev. D 39, 1947 (1989). 5. Y. V. Novozhilov, Introduction to Elementary Particle Physics (Pergamon, New York, 1975). 6. Particle Data Group, D. Groom et al., Eur. Phys. J. C 15, 1 (2000). 7. J.A. Oller, E. Oset, and J.E. Palomar, Phys. Rev. D 63, 114009 (2001). 8. J. Bijnens et al., Phys. Lett. B 374, 210 (1996); Nucl. Phys. B508, 263 (1997). 9. T.N. Truong, Phys. Rev. Lett. 61, 2526 (1988); 67, 2260 (1991); A. Dobado, M.J. Herrero, and T.N. Truong, Phys. Lett. B 235, 134 (1990); A. Dobado and J.R. Peláez, Phys. Rev. D 47, 4883 (1993); 56, 3057 (1997). 10. J.A. Oller, E. Oset, and J.R. Peláez, Phys. Rev. Lett. 80, 3452 (1998); Phys. Rev. D 59, 074001 (1999); 60, 099906(E) (1999); F. Guerrero and J.A. Oller, Nucl. Phys. B537, 459 (1999); B602, 641(E) (2001); A. Gomez Nicola and J. Peláez, Phys. Rev. D 65, 054009 (2002). 11. J. Nieves and E. Ruiz-Arriola, Phys. Rev. D 65, 036002 (2002). 12. S.D. Protopopescu et al., Phys. Rev. D 7, 1279 (1973). 13. P. Estabrooks and A.D. Martin, Nucl. Phys. B79, 301 (1974). 14. C.D. Froggat and J.L. Petersen, Nucl. Phys. B129, 89 (1977).0556-282110.1103/PhysRevD.65.077502https://hdl.handle.net/20.500.14352/58657©2002 The American Physical Society. This work was supported by the Spanish CICYT projects FPA2000-0956, PB98-0782 and BFM2000-1326Within chiral perturbation theory, we study elastic pion scattering in the I=0,J=2, channel, whose main features are the f(1270) resonance and the vanishing of the lowest order. By means of a chiral model that includes an explicit resonance coupled to pions, we describe the data and calculate the resonance contribution to the O(p(4)) and O(p(6)) chiral parameters. We also generalize the inverse amplitude method to higher orders, which allows us to study channels with vanishing lowest order. In particular, we apply it to the I=0,J=2 case, finding a good description of the f(2)(1270) resonance, as a pole in the second Riemann sheet.engChiral perturbation theory and the f(2)(1270) resonancejournal articlehttp://prd.aps.org/abstract/PRD/v65/i7/e077502http://prd.aps.orgopen access53Pion-Pion ScatteringOne-LoopMeson InteractionsForm-FactorsLow-EnergyLagrangiansUnitarizationAmplitudeFísica (Física)22 Física