Quark-mass dependence of the ρ and σ mesons from dispersion relations and chiral perturbation theory

Hanhart, ChristophPeláez Sagredo, José RamónRios, G.2023-06-202023-06-202008-030031-900710.1103/PhysRevLett.100.152001https://hdl.handle.net/20.500.14352/51707©2008 The American Physical Society. We thank G. Colangelo, S. Du¨rr, V. V. Flambaum, U. G. Meißner, and A. Rusetsky for their useful comments.We use the one-loop chiral perturbation theory π π -scattering amplitude and dispersion theory in the form of the inverse amplitude method to study the quark-mass dependence of the two lightest resonances of the strong interactions, the f_0(600) (σ) and the ρ meson. As the main results, we find that the rho π π coupling constant is almost quark mass independent and that the ρ mass shows a smooth quark-mass dependence while that of the σ shows a strong nonanalyticity. These findings are important for studies of the meson spectrum on the lattice.engQuark-mass dependence of the ρ and σ mesons from dispersion relations and chiral perturbation theoryjournal articlehttp://dx.doi.org/10.1103/PhysRevLett.100.152001http://journals.aps.orgopen access51-73Light scalar mesonsOne-loopScatteringUnitarizationParticlesAmplitudeUniverseFísica-Modelos matemáticosFísica matemática