  Recent experiment indicates that the behavior exhibited by the ratios
$E_{1^+}/M_{1^+}$ and $S_{1^+}/M_{1^+}$ of the $\gamma^* N \leftrightarrow
\Delta$ transition remain small and negative for $Q^2 \le 4.0 GeV^2$. It
implies that the perturbative QCD is still not applicable at these momentum
transfers. We show that these data can be explained in a dynamical model for
electromagnetic production of pions, together with a simple scaling assumption
for the bare $\gamma^* N \Delta$ form factors. Within our model we find that
the bare $\Delta$ is almost spherical and the electric E2 and Coulomb C2
quardrupole excitations of the physical $\Delta$ are nearly saturated by pion
cloud contribution in $Q^2 \le 4.0 GeV^2$.

Nuclear Theory;High Energy Physics - Phenomenology