RECOIL POLARIZATION OBSERVABLES IN COINCIDENT PION ELECTROPRODUCTION

We present an analysis of the recoil polarization observables in neutral pion electroproduction on the proton. In particular, for the N → Δ transition, we investigate the sensitivity of these observables to models of the resonant and non-resonant amplitudes. We find that the resonant quadrupole amplitudes have a large effect on the polarization response functions in the reaction plane while the Born terms significantly influence the polarization normal to this plane. At large four-momentum transfer, the higher nucleon resonances are found to interfere strongly with the Δ amplitudes. © 1990.