Evidence for a missing nucleon resonance in kaon photoproduction

New SAPHIR $p\left(\gamma {,K}^{+}\right)\Lambda$ total cross section data show a resonance structure at a total c.m. energy around 1900 MeV. We investigate this feature with an isobar model and find that the structure can be well explained by including a new $D_{13}$ resonance at 1895 MeV. Such a state has been predicted by a relativistic quark model at 1960 MeV with significant $\gamma N$ and $K\Lambda$ branching ratios. We demonstrate how the measurement of the photon asymmetry can be used to further study this resonance. In addition, verification of the predicted large decay widths into the $\eta N$ and ${\eta }^{\prime }N$ channels would allow distinguishing between other nearby $D_{13}$ states.