Since the turn of the century it becomes evident that the naive quark model is not capable to describe the rich phenomenology of hadrons, especially in the doubly heavy sector. For a large number of those states a molecular structure, where the states are understood as analogs to atomic nuclei, appears to be a natural description. In this talk I review the theory of hadronic molecules, how they can be described systematically in effective field theories and what imprint this structure leaves in observables. On a two examples I explain non-trivial predictions emerging from the molecular hypothesis that can be tested in future experiments and lattice QCD calculations, promising deep insights into the inner workings of QCD.

Biography

Christoph Hanhart is the recipient of the PIFI Distinguished Scientist Award (2025) and a member of the Particle Data Group (PDG). He studied physics in Bonn and Sydney. As a theoretical physicist he works on phenomena of the strong interaction at the boundary between nuclear and particle physics at the Jülich Research Centre and at the University of Bonn, where he also holds an extraordinary professorship. He is a world leading expert on investigations of exotic hadron states. He received the Teaching Award of the University of Bonn in 2018.

Inviter: Feng-Kun Guo