In-medium properties of the D-13(1520) nucleon resonance

The in-medium properties of the D-13(1520) nucleon resonance were studied v ia photoproduction of pi (0) mesons from nuclei (C, Ca, Nb, Pb) with the TA PS detector at the Mainz Microton accelerator. The inclusive (single and mu ltiple pion production) data disagree with model predictions which explain the disappearance of the second resonance bump in total photoabsorption via a medium modification of the D-13 --> N rho decay. The exclusive single pi (0) production data show no broadening of the resonance structure beyond F ermi smearing. Both results together cast doubt on attempts to explain the vanishing of the second resonance bump for nuclei by a broadening of the D- 13 resonance.