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The helicity amplitudes $A^{p}_{1/2}$ and $S^{p}_{1/2}$ for theelectromagnetic transition $\gamma^{*} N\to N^{*}(1535)$ are calculated in thequark model that is extended to include the lowest lying $qqqq\bar{q}$components in addition to the $qqq$ component. It is found that with admixtureof 5-quark components with a proportion of 20% in the nucleon and 25-65% in the$N^{*}(1535)$ resonance the calculated helicity amplitude $A^{p}_{1/2}$decreases at the photon point, $Q^{2}=0$ to the empirical range. The$qqqq\bar{q}$ components contain $s\bar s$ pairs, which is consistent with thesubstantial width for $N\eta$ decay of the $N^{*}(1535)$. The best descriptionof the momentum dependence of the empirical helicity amplitudes is obtained byassuming that the $qqqq\bar{q}$ components are more compact than the $qqq$component. However, this version of extended quark model still does not lead toa satisfactory simultaneous description of both $A^{p}_{1/2}$ and $S^{p}_{1/2}$although with significant improvement.

The role of the $qqqq\bar{q}$ components in the electromagnetic transition $\gamma^*N\to N^*(1535)$

The role of the $qqqq\bar{q}$ components in the electromagnetic transition $\gamma^N\to N^(1535)$