It is shown that the quadrupole transition in the processes γ+p⇆Δ is caused by quantum effects in the Skyrme model. Also the longitudinal cross section of ep→eΔ exists in this model. A new formula for ${\mu }_{\Delta p}$ is obtained. The mean-square radii of $G_M$($q^2$), $G_E$($q^2$), and $G_S$($q^2$) are computed.

• Received 8 September 1987

DOI:https://doi.org/10.1103/PhysRevD.37.1226