Multi-meson model applied to D → hhh

In this work, we discuss a new phenomenological model suited to all SU(3) mesonic two-body final-state interactions up to energies around 2 GeV to replace the standard isobar model. We show that the new model provides a clear indication of the mechanism responsible for the sharp rise observed in the ππ phase around 1 GeV. The phenomenological amplitudes proposed here are suited to any number of resonances, incorporate chiral symmetry at low energies, include coupled channels, and respect unitarity.