Nonperturbative Approach to Effective Chiral Lagrangians and Meson Interactions

Abstract

We develop a coupled channel unitary approach describing the behavior at higher energies of systems whose low-energy dynamics is given by effective $O({p}^{2})$ and $O({p}^{4})$ chiral Lagrangians. Our free parameters are those of the $O({p}^{4})$ Lagrangian. When applied to the meson-meson interaction, it yields a remarkable agreement with data up to $\sqrt{s}\ensuremath{\simeq}1.2\mathrm{GeV}$, dynamically generating the $\ensuremath{\sigma}$, ${f}_{0}$, ${a}_{0}$, $\ensuremath{\rho}$, and ${K}^{*}$ resonances. Further applications are also proposed.