Scattering parameters from Production Reactions

Highly non-trivial information about the strong interaction in its non-perturbative regime can be extracted from studies of hadron-hadron interactions at low energies. Moreover, these scattering parameters are an important input for few and many body calculations. Unfortunately direct scattering experiments are possible only for very few systems such that production reactions need to be employed to get access to few hadron systems. In this talk I will discuss how final state interactions shape invariant mass distributions of particle pairs in near threshold production reactions and how dispersion theory can be used to extract e.g. scattering lengths directly from those. In the chosen kinematics Dalitz plots can be used to monitor cross channel effects and to in this way control systematics. The method is contrasted with the so called femtoscopy that is used with the same goals, however, for production reactions far from threshold — differences and similarities are highlighted.