γ-ray production in neutral-current neutrino-oxygen interactions at energies above 200 MeV

We report the results of a calculation of the neutrino- and antineutrino-induced γ-ray production cross section for oxygen target. Our analysis is focused on the kinematical region of neutrino energy larger than ∼200 MeV, in which single-nucleon knockout is known to be the dominant reaction mechanism. The numerical results have been obtained using a realistic model of the target spectral function, extensively tested against electron-nucleus scattering data. We find that at neutrino energy 600 MeV the fraction of neutral-current interactions leading to emission of γ-rays of energy larger than 6 MeV is ∼41%, and that the contribution of the p3/2 state is overwhelming.