Measurement of neutrino-water interactions using nuclear emulsion detectors

Measurement of neutrino-water interactions is important for the current and future long-baseline neutrino oscillation experiments. The NINJA experiment aims to measure such interactions using a nuclear emulsion detector called Emulsion Cloud Chamber (ECC). The ECC has a sub-micron position resolution, thus short tracks of low-momentum charged particles can be detected. The momentum threshold for protons can be down to 200 MeV/c.
From November 2019 to February 2020, the NINJA experiment conducted its first physics run in J-PARC using the T2K high-intensity neutrino beam. To achieve a better understanding of neutrino interactions, we have improved methods of event reconstructions from the previous pilot experiments. In this poster, the current status of the neutrino interaction analysis and expected outcomes will be discussed.