Measurement of polarization observables in multi-meson photoproduction off the proton with the CBELSA/TAPS experiment

The reaction γp → pπ 0π 0 was analyzed using data of the CBELSA/TAPS experiment where linearly polarized photons impinged on a transversely polarized butanol target. Single and double polarization observables were extracted. Within the BnGa-PWA resonance parameters were determined. N∗ and ∆∗ resonances demonstrated systematic differences in their decay branching ratios via excited hadrons which hint at the internal structure of these states.