Photoexcitation of Baryon Resonances - News from the D13(1520)

Abstract

The so-called second resonance region of the nucleon comprises the states P11(1440), D13(1520) and S11(1535). During the last few years photoproduction experiments have largely contributed to a better understanding of these states, but the strong suppression of the resonance structure in total photoabsorption experiments from nuclei is still not understood. The D13-resonance dominates the resonance structure due to its large photon coupling. In this contribution new results for the excitation and decay modes of the D13 on the free nucleon and first results for the in-medium behavior of the resonance are summarised.