A relativistic model for the quasifree exclusive photoproduction of η
mesons on nuclei is extended to include both non-local and medium effects. The
reaction is assumed to proceed via the dominant contribution of the
S11​(1535) resonance. The complicated integrals resulting from the
non-locality are simplified using a modified version of a method given by
Cooper and Maxwell. The non-locality effects are found to affect the magnitude
of the cross section. Some possibilities reflecting the effects of the medium
on the propagation and properties of the intermediate S11​ resonance are
studied. The effects of allowing the S11​ to interact with the medium via
mean field scalar and vector potentials are considered. Both broadening of
width and reduction in mass of the resonance lead to a suppression of the
calculated cross sections.Comment: 19 pages, 7 figure