Insights into the gamma* N -> Delta transition

Abstract

The γ* N -> Δ(1232) transition is a window on hadron shape deformation, the applicability of perturbative QCD at moderate momentum transfers, and the influence of nonperturbative phenomena on hadronic observables. We explain that the Ash-convention magnetic transition form factor must fall faster than the neutron's magnetic form factor and nonzero values for the associated quadrupole ratios reveal the impact of quark orbital angular momentum within the nucleon and Δ(1232); and show that these quadrupole ratios do approach their predicted asymptotic limits, albeit slowly.

6 pages, 5 figures. To appear in Phys. Rev. C (Rapid Comm.)