Neutrino-nucleus reactions via neutral and charged currents by the quasi-particle random phase approximation (QRPA)

We developed the quasi-particle random phase approximation (QRPA) for neutrino reactions on even-even nuclei via neutral current (NC) and charged current (CC). The QRPA has been successfully applied for nuclear beta and beta beta decays. To describe neutrino-nucleus reactions, general multipole transitions by the weak interaction with finite momentum transfers are calculated for NC and CC reactions with detailed formulas. Since we consider neutron-proton (np) pairing as well as neutron-neutron (nn) and proton-proton (pp) pairing correlations, the nn + pp QRPA and the np QRPA are combined in a framework, which enables us to describe both NC and CC reactions in a consistent way. Numerical results for nu-C-12, -Fe-56 and -Ni-56 reactions are shown to match with other theoretical calculations and well reproduce available experimental data.