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

TL;DR

This paper determines the electrocouplings of the $N(1675)5/2^-$ resonance using recent CLAS data, revealing significant meson-baryon contributions to the transition amplitudes at high momentum transfer.

Contribution

It provides the first detailed extraction of the $N(1675)5/2^-$ electrocouplings from CLAS data, highlighting the importance of meson-baryon effects over three-quark models.

Findings

The $A_{1/2}^p$ amplitude is significantly larger than three-quark predictions.

The $A_{3/2}^p$ amplitude is much smaller than $A_{1/2}^p$.

Results align with dynamical coupled-channel model predictions.

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.