We argue that the low-lying scalar-meson nonet [1] makes part of a subset of a family of infinitely many scalar-meson nonets, which in turn makes part of a family of infinitely many quark-antiquark bound states and resonances. We outline the properties of this subset.

By means of a coupled channel non-perturbative unitary approach, it is possible to extend the strong constrains of Chiral Perturbation Theory to higher energies. In particular, it is possible to reproduce the lowest lying resonances in meson-meson scattering up to 1.2 GeV using the parameters of the O(p) and O(p) Chiral Lagrangian. We report on an update of these results examining their possibl...

The S-matrix characterizing the scattering of pions from nucleons is calcu-lated in the context of skyrmion models of the nucleon. These are models inwhich the nucleon is considered a soliton in the field of pions. The spectrum ofnucleon and delta resonances in the Skyrme model is calculated and found o bein overall good agreement with Nature. Model-independent sum rules between...