Chiral dynamics with vector fields: an application to $\pi \pi$ and $\pi K$ scattering

A theoretical study of Goldstone boson scattering based on the chiral Lagrangian with vector meson fields is presented. In application of a recently developed novel approach we extrapolate subthreshold partial-wave amplitudes into the physical region. The constraints set by micro-causality and coupled-channel unitarity are kept rigourously. It is shown that already the leading order subthreshold amplitudes lead to s- and p-wave $\pi \pi$ and $\pi K$ phase shifts are in agreement with the experimental data up to about 1.2 GeV.