We perform detailed studies of charmonium decays and the decays of the recently discussed charmonium-like X, Y and Z states using amplitude analysis tools. Our first object of study are the decays of a J/ψ or a ψ' to three pions, which are surprisingly different - see the plots below - a problem known as the ρπ-puzzle.
More information about amplitude analysis and tools development in Mainz can be found on the pages of the PALUMA group, with which we are closely collaborating.