Measurement of spin correlation parameters in the Δ region for the 1H⃗(e⃗,e′) reaction

Sensitivity to the quadrupole transition form factors (C2 and E2) of the N-Δ excitation can be obtained by measuring double-polarization electromagnetic observables in the Δ-region. Such measurements have been carried out with the internal target facility at NIKHEF. Radiative corrections are an important ingredient of the data interpretation. They need to be evaluated carefully, taking into account their spin-dependence, in order to compare the data to theoretical models of pion electroproduction. From these comparisons the E2/M1 and C2/M1 ratios can be extracted.