Coincidence Experiment on Inelastic Electron-Proton Scattering in the Region of theΔ(1236)atq2=−0.35and−1.0(GeVc)2

Abstract

We present measurements on inelastic electron-proton scattering in the region of the $\Delta \mathrm{}\left(1236\right)\mathrm{}$ resonance for two values of $q^2$. A fit to the single-arm and the ${\pi }^0$-electroproduction cross sections gave a separation of the resonance and the nonresonant background contribution. The transition form factor $G_M^{*}\left(q^2\right)$ was determined and shown to have a different dependence on $q^2$ than the magnetic nucleon form factor, confirming earlier measurements. A fit to the angular dependence of the ${\pi }^0$-electroproduction cross section gives some indications that smaller multipole amplitudes contribute to the resonance besides the dominating $M_{1+}$ amplitude.