Generalized Linear Sigma Model Framework for Scalar and Pseudoscalar Mesons Below 2 GeV

Within the framework of a generalized linear sigma model that includes two nonets of scalar mesons (a two-quark nonet and a four-quark nonet) and two nonets of pseudoscalar mesons (a two-quark nonet and a four-quark nonet) a collective description of scalar and pseudoscalar mesons below 2 GeV will be presented. Particularly, the quark contents of these states as well as their roles in various low-energy processes (such as various scattering amplitudes as well as decays) will be discussed.