Measurements of protons and charged pions emitted from $\nu_{\mu}$ charged-current interactions on iron at a mean neutrino energy of 1.49$\,$GeV using a nuclear emulsion detector

TL;DR

This paper presents detailed measurements of muons, protons, and pions emitted from muon neutrino interactions on iron using a nuclear emulsion detector, revealing discrepancies with models and demonstrating the detector's high-resolution capabilities.

Contribution

First detailed measurements of neutrino-induced charged particles on iron at low momentum thresholds using a nuclear emulsion detector, providing data to improve interaction models.

Findings

Observed significant differences between data and Monte Carlo predictions.

Achieved lowest momentum thresholds for protons and pions in such measurements.

Demonstrated the effectiveness of nuclear emulsion detectors for detailed neutrino interaction studies.

Abstract

This study conducted an analysis of muons, protons, and charged pions emitted from $\nu_{\mu}$ charged-current interactions on iron using a nuclear emulsion detector. The emulsion detector with a 65$\,$kg iron target was exposed to a neutrino beam corresponding to 4.0$\times$10$^{19}$ protons on target with a mean neutrino energy of 1.49$\,$GeV. The measurements were performed at a momentum threshold of 200 (50)$\,$MeV/$c$ for protons (pions), which are the lowest momentum thresholds attempted up to now. The measured quantities are the multiplicities, emission angles, and momenta of the muons, protons, and charged pions. In addition to these inclusive measurements, exclusive measurements such as the muon-proton emission-angle correlations of specific channels and the opening angle between the protons of CC0$\pi$2$p$ events were performed. The data were compared to Monte Carlo (MC) predictions and some significant differences were observed. The results of the study demonstrate the capability of detailed measurements of neutrino-nucleus interactions using a nuclear emulsion detector to improve neutrino interaction models.