Coherent γ-production in (p,p′) reactions in nuclei in the Δ resonance region

We study the process of coherent photon production in nuclei induced by the (p,p′) reaction around the Δ excitation region. The cross sections are about 200 times smaller than the corresponding ones for coherent pion production but within measurable range with present machines. The cross section selects the transverse part of the NN→NΔ transition, while coherent pion production selects the longitudinal one. The reactions are complementary and show different aspects of Δh propagation through the nucleus which are discussed here.