First measurement using a nuclear emulsion detector of theνμcharged-current cross section on iron around the 1 GeV energy region

Abstract

We have carried out νμ charged-current interaction measurement on iron using an emulsion detector exposed to the T2K neutrino beam in the J-PARC neutrino facility. The data samples correspond to 4.0 × 1019 protons on target, and the neutrino mean energy is 1.49 GeV. The emulsion detector is suitable for precision measurements of charged particles produced in neutrino-iron interactions with a low momentum threshold thanks to a thin-layered structure and sub-μm spatial resolution. The charged particles are successfully detected, and their multiplicities are measured using the emulsion detector. The cross section was measured to be σFeCC = (1.28 ± 0.11(stat.)+0.12-0.11(syst.)) × 10-38 cm2/nucleon. The cross section in a limited kinematic phase space of induced muons, θμ < 45° and pμ > 400 MeV/c, on iron was σFeCC phase space= (0.84 ± 0.07(stat.)+0.07-0.06(syst.)) × 10-38 cm2/nucleon. The cross-section results are consistent with previous values obtained via different techniques using the same beamline, and they are reproduced well by current neutrino interaction models. These results demonstrate the capability of the detector in the detailed measurement of neutrino-nucleus interactions around the 1 GeV energy region.

Design and performance of a scintillation tracker for track matching in nuclear-emulsion-based neutrino interaction measurement

“…The other efficiencies will be described in another paper. In the results from the NINJA pilot runs [6,7], the muon detection efficiency was dropped mainly due to inefficiency in matching between the emulsion detectors and the scintillator detectors which was around 90%. The improvement in this efficiency will be also reported in another paper.…”

“…Neutrino Interaction research with Nuclear emulsion and J-PARC Accelerator (NINJA) is an experiment aiming to measure neutrino-nucleus, especially neutrino-water, interactions using a high-intensity neutrino beam produced in Japan Proton Accelerator Research Complex (J-PARC), and nuclear emulsion films. Since 2014, the NINJA experiment has carried out a series of pilot runs [5,6,7]. Nuclear emulsion films have sub-µm position resolution and O(mrad) angle resolution thanks to their fine granularity.…”

“…In the previous runs of the NINJA experiment, an emulsion shifter [7,10] or a scintillating fiber tracker [6] was used for the muon track matching and covered an area around 30 cm × 30 cm. The emulsion shifter was originally developed for cosmic-ray electron balloon experiments [11] and used in the GRAINE experiment [12,13].…”

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

“…A series of neutrino-nucleus interaction measurements were conducted as part of the NINJA experiment [14][15][16] using an emulsion detector in the near detector hall of the T2K experiment at J-PARC. The aim was to precisely measure charged particles from neutrino interactions in the 1 GeV energy region.…”

“…Previous studies have reported the detector performance of the 2 kg iron pilot measurement [14] and the results of the 3 kg water pilot measurement [15]. Further, the measurement of the flux-averaged cross-sections and muon kinematics of the ν µ CC interaction of the 65 kg iron pilot measurement [16] have also been reported. The cross-section results of these studies are consistent with the T2K results [17][18][19] and Monte Carlo (MC) simulations.…”