A high-resolution study of the C(γ,p) reaction with 49-78.5 MeV tagged photons

We present tabulated cross-section measurements for the reaction C(γ, p) leading to resolved, low-lying, excited states of B. The measurements were obtained using tagged photons of 49-78.5 MeV and for mean laboratory proton emission angles from 65° to 115°. The proton excitation energy spectra are dominated by the ground state ( 3 2), 2.13 MeV ( 1 2), 5.02 MeV ( 3 2) and doublet ( 7 2, 1 2) states of B. No evidence is found for the population of the 4.45 MeV ( 5 2) state. Our analysis demonstrates that both the ground-state and excited-state cross-section data scale with momentum mismatch. The data are qualitatively discussed within the context of the existing (e, e'p) data and direct knockout and quasideuteron models. A consistent and quantitative understanding of the data will require more sophisticated models than are currently available.