N∗N∗ and Δ∗Δ∗ decays into Nπ0π0Nπ0π0

Decays of baryon resonances in the second and the third resonance region into Nπ0π0Nπ0π0 are studied by photoproduction of two neutral pions off protons. Partial decay widths of N∗N∗ and Δ∗Δ∗ resonances decaying into Δ(1232)πΔ(1232)π, N(ππ)SN(ππ)S, N(1440)P11πN(1440)P11π, and N(1520)D13πN(1520)D13π are determined in a partial wave analysis of this data and of data from other reactions. Several partial decay widths were not known before. Interesting decay patterns are observed which are not even qualitatively reproduced by quark model calculations. In the second resonance region, decays into Δ(1232)πΔ(1232)π dominate clearly. The N(ππ)SN(ππ)S-wave provides a significant contribution to the cross section, especially in the third resonance region. The P13P13(1720) properties found here are at clear variance to PDG values.