Photoproton cross section for 19F

Proton energy spectra have been measured at 900 for the 19F(e,e'p)18O reaction in the giant resonance region. The (γ,p0) and (γ,p1) differential cross sections are extracted from the proton energy spectra by using virtual-photon spectra. The integrated differential cross section of the (γ,p0) and (γ,p1) reactions are 1.80+-0.27 and 0.50+-0.45 MeV-mb/sr, respectively. The results are discussed with the shell model theory by comparing with the (γ,p0) cross section of the neighboring 4n-nucleus 20Ne. A significant increase of the proton yield leaving the non-ground states is found at 25 MeV of the incident electron energy. This is discussed in terms of the core excitation effect. (auth.)