Dispersive analysis of pion-nucleon scattering and the pion-nucleon sigma term

Pion–nucleon scattering is one of the most fundamental processes in nuclear and hadronic physics, with applications that range from the scalar couplings of the nucleon to the long-range part of two-pion-exchange potentials and three-nucleon forces in Chiral Effective Field Theory. In this talk, we show how the fruitful combination of dispersion-theoretical methods with modern high- precision data of hadronic atoms allows for a determination of pion–nucleon scattering amplitudes at low energies with an unprecedented accuracy. Special attention will be paid to the extraction of the pion–nucleon σ-term, discussing in detail the current tension with recent lattice results, the determination of the pion–pion continuum in the electromagnetic nucleon form factors, and the determination of the low-energy constants of chiral perturbation theory.