The NINJA experiment aims at a precise measurement of neutrino-nucleus interactions in sub-multi GeV region using a nuclear emulsion detector at J-PARC.
By using nuclear emulsions, NINJA can measure neutrino interactions with high precision, including acceptance close to 4pi, very low energy threshold (energy threshold for protons is 20MeV), good particle identification capability, and various targets such as water, CH, and iron targets. It also allows us to study multi-nucleon interactions (2 particle-2 hole interactions).
We implemented a physics run of 75kg water target, 15kg CH target, and 130kg iron target at J-PARC neutrino beamline in 2019-2020. Then in 2020-2021, we also implemented a test experiment with a heavy water target to measure neutrino-nucleon interactions. (neutrino-nucleon interactions are extracted by subtracting the heavy water and water measurements)
Since it is expected that such precise data on neutrino-nucleus cross-sections will be available in the near future, so in this mini-workshop, we will discuss with theorists what they think is important for current and future studies of neutrino-nucleus interaction.