The \gamma-ray production in neutral-current neutrino oxygen interaction in the energy range above 100 MeV

Abstract

We calculate the cross section of the gamma-ray production from neutral-current neutrino-oxygen quasi-elastic interaction, $\nu +\widehat{16}O\to \nu +p{+}^{15}N\ast$, or $\nu {+}^{16}O\to \nu +n{+}^{15}O\ast$, in which the residual nuclei (15N* or 15O*) lead to the gamma-ray emission with gamma-ray energy >6 MeV at the branching ratio of 41%. Above 200 MeV, this cross section dominates over that of gamma-ray production from the inelastic reaction, $\nu {+}^{16}O->\nu {+}^{16}O\ast$. In the present calculation, spectral function and the spectroscopic factors of $1p_{1/2},1p_{3/2}and1s_{1/2}$ states are essential. The gamma-ray production is dominated by the deexcitation of $1p_{3/2}$ state of the residual nucleus.