Phenomenological Analysis of Neutral Pion Electroproduction and theγNN*Form Factor

Abstract

We have analyzed recent data on neutral pion electroproduction in the region of the $N^{*}\mathrm{}\left(1236\right)\mathrm{}$ resonance phenomenologically to determine the magnitude of the dominant magnetic dipole amplitude and its interference with the ${E_1}^{+}$ electric quadrupole amplitude. Evidence is found for the existence of significant scalar multipoles. The four-momentum-transfer dependence of the magnetic dipole amplitude is interpreted in terms of the $\gamma N{N}^{*}$ transition form factor between 0.05 and 0.4 ${(\mathrm{B}\mathrm{e}\mathrm{V}/\mathit{c})}^2$.