**Principal Investigator:** Andreas Schäfer, Institute for Theoretical Physics, Regensburg University

**HPC Platform used:** SuperMUC and SuperMUC-NG of LRZ

**Local Project ID:** pn56yo

The nucleon has an extremely complicated many-body wave function because QCD is very strongly coupled, very non-linear and characterized by massive quantum fluctuations. Its investigation started with collinear processes and has by now progressed to non-collinear ones. The latter are characterized by non-trivial parallel transport, leading to observable effects. Many of these are described by TMDs the properties of which are not yet well understood and are planned to be studied at the new Electron Ion Collider. We have calculated one of the most important of these properties on the lattice. Only in 2020, first lattice calculations, all using alternative approaches, of this quantity were published. All results agree within error.