Comparison of scalar resonances using two unitarisation procedures in ππ and πK scattering

We review two previous approaches to studying pseudoscalar meson-meson scattering amplitudes to beyond 1 GeV using non-linear and linear chiral Lagrangians. In these approaches we use two different unitarisation techniques - a generalised Breit Wigner prescription and K-matrix unitarization respectively. We report some new findings on K-matrix unitarisation of ππ and πK scattering in the non-linear chiral Lagrangian approach and make some related remarks about the light scalar mesons.