The $\sigma$-meson: four-quark vs. two-quark components and decay width in a Bethe-Salpeter approach

Nico Santowsky, Gernot Eichmann, Christian S. Fischer +2

We study the dynamical generation of resonances in isospin singlet channels with mixing between two- and four-quark states. To this end we generalise a Bethe-Salpeter approach to f…