Extracting meson-baryon contributions to the electroexcitation of the $N(1675){\frac{5}{2}}^-$ nucleon resonance

Abstract

We report on the determination of the electrocouplings for the transition from the proton to the $N(1675){\frac{5}{2}}^-$ resonance state using recent differential cross section data on $e p \rightarrow e\pi^+ n$ by the CLAS collaboration at $1.8 \le Q^2 < 4.5$GeV$^2$. The data have been analyzed using two different approaches, the unitary isobar model and fixed-t dispersion relations. The extracted $\gamma^* p\rightarrow N(1675){\frac{5}{2}}^-$ helicity amplitudes show considerable coupling through the $A^p_{1/2}$ amplitude, that is significantly larger than predicted three-quark contribution to this amplitude. The amplitude $A^p_{3/2}$ is much smaller. Both results are consistent with the predicted sizes of the meson-baryon contributions at $Q^2 \geq 1.8 $GeV$^2$ from the dynamical coupled-channel model.