Nuclear de-excitation associated with neutrino-carbon interactions

Neutrino interactions in low energy regions below 30 MeV, where the experimental searches for supernova relic neutrino are conducted, have a large uncertainty due to complicated nuclear effects such as the Pauli blocking effect and de-excitation of a residual nucleus. Understanding the effect of nuclear de-excitation is especially critical since neutrons measured by liquid scintillator detectors can be emitted via de-excitation. We build a systematic method to predict nuclear de-excitation associated with neutrino-carbon interaction using TALYS and Geant4. This prediction is combined with the results of neutrino event generators, and we find a large increase in neutron multiplicity.