We report further evidence for N(1900)P13 from an analysis of a large variety of photo- and pion-induced reactions, in particular from the new CLAS measurements of double polarization observables for photoproduction of hyperons. The data are consistent with two classes of solutions both requiring contributions from N(1900)P13 but giving different N(1900)P13 pole positions. (M−iΓ/2)=(1915±50)−i(90±25) MeV covers both solutions. The small elasticity of 10% or less explains why it was difficult to observe the state in πN elastic scattering. N(1900)P13 is a 2-star resonance which is predicted by symmetric three-quark models. In diquark-quark models, the existence of the state is not expected.
@article{arxiv.0707.3600,
title = {Further evidence for N(1900)P_{13} from photoproduction of hyperons},
author = {V. A. Nikonov and A. V. Anisovich and E. Klempt and A. V. Sarantsev and U. Thoma},
journal= {arXiv preprint arXiv:0707.3600},
year = {2008}
}