A recently developed quark model approach to pseudoscalar meson photoproduction is extended to electroproduction process for the $\eta$ meson in the kinematics of momentum transfer $Q^2 \leq$ 4 (GeV/c)$^2$ and total center of mass energy $W \leq$ 1.6 GeV. Existing data are well reproduced and the roles of the $S_{ 11}(1535)$ and $D_{ 13}(1520)$ resonances are closely investigated. In the study of the longitudinal excitation of the $S_{ 11}(1535)$ resonance, a reliable constraint on the $S_{ 11}(1535)$ properties is obtained by cleanly removing the electromagnetic transition from the $\gamma_{ (v)} p \to S_{ 11}(1535) \to \eta p$ amplitude. Thus, the fitted quantities can be determined with an uncertainty of about 15%. This could be the first direct constraint on the $S_{ 11}(1535)$ properties in theory.
Categories: nucl-th