A coupled channel unitary chiral approach to the meson-meson interaction and pion-pion scattering in a nuclear medium

摘要

A new tool which combines chiral perturbation theory and unitarity in coupled channels is applied with success to the study of the meson-meson interaction, extending the theoretical predictions up to {radical}s = 1.2 GeV, hence improving considerably the convergence radius of conventional chiral perturbation theory, {chi}PT. The method is applied to obtain the meson-meson phase shifts and inelasticities as well as the isoscalar {pi}{pi} scattering amplitude inside a nuclear medium.