Seminar über aktuelle Frage der theoretischen Kernphysik
Quark mass dependence of meson-meson scattering amplitudes and elastic resonances from unitarized ChPT
José R. Peláez (Madrid)
We will discuss some of the recent results and current developments of our group on the study of the quark mass dependence of meson-meson scattering using unitarized Chiral Perturbation Theory (ChPT). We will review how using ChPT to calculate the subtraction constants in a dispersion relation, we are able to reproduce the elastic meson-meson scattering up to roughly 1 GeV, including the poles associated to the light vector and scalar mesons. Then, by changing the light and strange quark masses we can study the behavior of the mass, width and couplings of these light resonances. Predictions for the pion-pion phase shift behavior, either for standard or unitarized ChPT will also be shown. All these results compare fairly well with recent calculations on the lattice.