Progress in the calculation of nucleon transition form factors

Abstract

We give a brief account of the Dyson-Schwinger and Faddeev-equation approach and its application to nucleon resonances and their transition form factors. We compare the three-body with the quark-diquark approach and present a quark-diquark calculation for the low-lying nucleon resonances including scalar, axialvector, pseudoscalar and vector diquarks. We also discuss the timelike structure of transition form factors and highlight the advantages of form factors over helicity amplitudes.

Comments: 8 pages, 8 figures, 2 tables. Proceedings of the ECT* Workshop "Nucleon Resonances: From Photoproduction to High Photon Virtualities", October 12-16, 2015, Trento, Italy