Test forN*(1400)Dominance of Nucleonic Form Factors

Abstract

By assuming that "nucleonic" form factors are dominated by the contribution of the $N^{*}\mathrm{}\left(1400\right)\mathrm{}$ resonance (which is the only object having the same quantum numbers as the nucleon), the relation $\frac{g_{\gamma }\mathrm{NN}}{g_{\pi }\mathrm{NN}}=\frac{g_{\gamma }N{N}^{*}}{g_{\pi }N{N}^{*}}$ is derived (the $g$'s are coupling constants, and only magnetic coupling to the photon is considered). A recent phase-shift analysis of photoproduction off protons by Chau, Dombey, and Moorhouse gives a value for $g_{\gamma }N{N}^{*}$ agreeing in sign but twice too large.