Electromagnetic nucleon-delta transition in the perturbative chiral quark model

We apply the perturbative chiral quark model to the $\gamma \overrightarrow{N}\Delta$ transition. The four-momentum dependence of the respective transverse helicity amplitudes $A_{1/2}$ and $A_{3/2}$ is determined at one loop in the pseudoscalar Goldstone boson fluctuations. Inclusion of excited states in the quark propagator is shown to result in a reasonable description of the experimental values for the helicity amplitudes at the real-photon point.