Propagators of resonances and rescatterings of the decay products
  Hadronic resonance propagators which take into account the analytical properties of decay processes are built in terms of the dispersion relation technique. Such propagators can describe multi-component systems, for example, those when quark degrees of freedom create a resonance state, and decay products correct the corresponding pole by adding hadronic deuteron-like components. Meson and baryon states are considered, examples of particles with different spins are presented. 
A.V. Anisovich, V.V. Anisovich, M.A. Matveev, A.V. Sarantsev, A.N.   Semenova, J. Nyiri
hep-ph