Photoproduction of a πN pair on nuclei and isobar configurations

A model of πN pair photoproduction on nuclei at high momentum transfer is presented. The A(γ,πN)B reaction amplitude is obtained by means of an extended impulse approximation, according to which the nuclear wave function includes delta-isobar components in addition to nucleon components. A one-particle transition operator is defined in terms of the two-body γN→πN and γΔ→πN photoproduction amplitudes. Direct and exchange mechanisms of the nuclear photoproduction reaction are studied, and numerical estimates are made and presented of and differential cross sections at photon incident energies in the Δ(1232) resonance region.