The properties of the σ and κ resonances in a new unitarization approach

A new unitarization approach is discussed and applied to study the elastic πK scattering process. The existence of the light κ resonance is firmly established if the scattering length in the I=1/2 channel does not deviate too much from its value obtained from chiral perturbation theory, and a precise determination of the mass and width of the κ resonance requires a precise determination of the scattering length parameter.