Measurement of the Electromagnetic-Transition Form Factor for theS11(1535)Resonance

We have measured the cross section for the process $e+p\to e^{\prime }+p+{\eta }^0$ near threshold for values of the four-momentum transfer between 0.15 and 1.5 ${\left(\frac{\mathrm{GeV}}{c}\right)}^2$. Assuming that the cross section is dominated by production of the $S_{11}\mathrm{}\left(1535\right)\mathrm{}$ resonance, we have compared our data with quark-model calculations which predict the transition matrix elements for the reaction $e+p\to e^{\prime }+S_{11}\mathrm{}\left(1535\right)\mathrm{}$.