The constituent structure of hadrons from a non-perturbative QCD approach

The nonperturbative regime of Quantum Chromodynamics (QCD) is to this day a challenging issue in many seemingly disconnected fields of hadron and flavor physics. Several approaches to numerical techniques and effective modeling have been developed over the past three decades to compute hadronic amplitudes dominated by nonperturbative contributions, amongst which leptonic decay constants, charge radii, electromagnetic and transition form factors or parton distribution functions at large x. The most popular approaches comprise relativistic quark models, QCD sum rules and most recently AdS/QFT models, whereas Lattice-QCD provides in principle an ab initio machinery within certain approximations and limitations.

A particular nonperturbative formulation of QCD are Dyson-Schwinger equations using symmetry-preserving and Poincaré-invariant truncation schemes. I will discuss the current status and review recent results in Dyson-Schwinger approaches to meson and baryon phenomenology. Among the topics to be high-lighted are: a symmetry-preserving computation and predictions for the q^2-dependence of u- and d-quark Dirac and Pauli form factors in the proton, which exposes the critical role played by diquark correlations within the nucleon; effective heavy-meson couplings and transition form factors; and what is to be expected from a Dyson-Schwinger based computation that simultaneously correlates the masses of meson and baryon ground- and excited-states.