2π-PHOTOPRODUCTION from Clas and Cb-Elsa - the Search for Missing Resonances

2π-photoproduction is one of the promising reactions to search for baryon resonances that have been predicted but have not yet been observed. The γp → pπ⁰π⁰ (CB-ELSA) and the γp → pπ⁺π^- (CLAS) data show interesting resonance structures. A partial wave analysis (PWA) has to be done to determine which baryon resonances contribute, what their quantum numbers and their relative couplings to the different accessible p2π-channels and to the photon are. First preliminary PWA-results on the lowest energy pπ⁰π⁰ data (√ s < 1.8 {GeV}; ) look very promising. From an extension of this analysis to higher energies combining the pπ⁰π⁰ and the pπ⁺π^--data, one can expect interesting results on resonances decaying into ∆π, Nρ, N(ππ)_s, N*π, and Δ*π.