f_(600), ρ(800), ρ(770) and K*(892), quark mass dependence from unitarized SU(3) Chiral Perturbation Theory

Abstract

We study the strange and non-strange quark mass dependence of the parameters of the f_0(600), κ(800), ρ(770) and K*(892) resonances generated from elastic meson-meson scattering using unitarized one-loop Chiral Perturbation Theory. We fit simultaneously all experimental scattering data up to 0.8-1 GeV together ith lattice results on decay constants and scattering lengths up to a pion mass of 440 MeV. Then, the strange and non-strange quark masses are varied from the chiral limit up to values of interest for lattice studies. In these amplitudes, the mass and width of the ρ(770) and K* (892) present a similar and smooth quark mass dependence. In contrast, both scalars present a similar non-analyticity at high quark masses. Nevertheless the f_0(600) dependence on both quark masses is stronger than for the к(800) and the vectors. We also confirm the lattice assumption of quark mass independence of the vector two-meson coupling that, in contrast, is violated for scalars