Baryons as Relativistic Three-Quark Bound States

by Prof. Reinhard Dr. Alkofer (Universität Graz)

Monday 9 Jul 2018, 14:15 → 16:45 Europe/Berlin

3344 (TUM - Physics Department - Garching)

The spectrum and electromagnetic properties of baryons described as relativistic three-quark bound states within QCD are investigated by employing a functional approach based on Dyson-Schwinger and Bethe-Salpeter equations. The general aim of the presented approach is to identify the underlying physical mechanisms behind the plethora of observable phenomena in hadron physics in terms of the underlying quark and gluon degrees of freedom. Considering the composite nature of baryons, while keeping Poincaré-invariance, leads in a model independent way to highly non-trivial structural properties explored by the coupling to external (electromagnetic and axial) currents and a rich excitation spectrum.

It is described how quantitative results are obtained in this framework. The connection to lattice QCD as well as the relation to the quark model, which still serves as a reference to distinguish `expected' from `unexpected’ physics, are elucidated. Recent results on the spectrum of non-strange and strange baryons as well as on their elastic and transition form factors will be given. The perspective on two-photon processes and Compton scattering within the Dyson-Schwinger framework is outlined and confronted with lattice QCD and the available experimental data.