Decays of mesons and tau leptons into three hadrons serve as a tool in studying both
spectroscopy and the weak dynamics of heavy flavour decays. State of the art analyses of
experimental data are now able to determine the underlying decay amplitudes with less and less
model dependence, often projected onto the JPC of a 2-body subsystem. To explore the wealth
of new information and to extract the sought-for physics observables, however, requires a new
quality of mathematical description of such amplitudes. These are governed by the strong
interaction among these hadrons. While for almost 50 years such descriptions relied on the
idealized isobar picture (including S-wave scattering of two hadrons), high precision data
require a more refined understanding covering the full spectral distribution of these complex
amplitudes. Final state interaction, triangular diagrams, chiral dynamics, Regge phenomenology
and dispersion relations are just some of the ingredients used for this purpose.
The TRR110 workshop will joint theorists and experimentalists aiming to address above topics.