arXiv:hep-ph/0304033·v2·High Energy Physics — Phenomenology
Electromagnetic nucleon-delta transition in the perturbative chiral quark model
K. Pumsa-ard🇩🇪 · V.E. Lyubovitskij🇩🇪 · Th. Gutsche🇩🇪 · Amand Faessler🇩🇪 · S. Cheedket (Tuebingen U.)🇩🇪
Abstract
We apply the perturbative chiral quark model to the gamma 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.
Comments: 25 pages