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Results are presented for the first measurement of the double-polarizationhelicity asymmetry E for the $\eta$ photoproduction reaction $\gamma p\rightarrow \eta p$. Data were obtained using the FROzen Spin Target (FROST)with the CLAS spectrometer in Hall B at Jefferson Lab, covering a range ofcenter-of-mass energy W from threshold to 2.15 GeV and a large range incenter-of-mass polar angle. As an initial application of these data, theresults have been incorporated into the J\"ulich model to examine the case forthe existence of a narrow $N^*$ resonance between 1.66 and 1.70 GeV. Theaddition of these data to the world database results in marked changes in thepredictions for the E observable using that model. Further comparison withseveral theoretical approaches indicates these data will significantly enhanceour understanding of nucleon resonances.

First measurement of the helicity asymmetry $E$ in $\eta$ photoproduction on the proton