Speaker
Description
Electromagnetic Form factors give information on the internal dynamics of hadrons. They are theoretical input to hadron transition electromagnetic currents in calculations of the structure of hadrons. Their direct measurement in the space-like and time-like kinematic regime, respectively, is made through differential cross sections and polarization observables of electron scattering and electron-positron annihilation reactions. In this talk I review what a variety of recent experimental data on low-lying nucleon resonance electromagnetic excitations can tell us about the evolution of the relevant degrees of freedom and the photon-baryon couplings in different regimes. The importance of multiquark meson-baryon decay channels and meson-cloud configurations is addressed within a relativistic quark model calculation.
