The OPERA experiment was designed to discover the v
appearance in a v
beam, due to neutrino oscillations. The detector, located in the underground Gran Sasso Laboratory, consisted of a nuclear ...photographic emulsion/lead target with a mass of about 1.25 kt, complemented by electronic detectors. It was exposed from 2008 to 2012 to the CNGS beam: an almost pure v
beam with a baseline of 730 km, collecting a total of 1.8·10
protons on target. The OPERA Collaboration eventually assessed the discovery of v
→v
oscillations with a statistical significance of 6.1 σ by observing ten v
CC interaction candidates. These events have been published on the Open Data Portal at CERN. This paper provides a detailed description of the v
data sample to make it usable by the whole community.
Abstract
We have carried out $\nu_{\mu}$ 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 $4.0 \times 10^{19}$ 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-$\mu$m spatial resolution. The charged particles are successfully detected, and their multiplicities are measured using the emulsion detector. The cross section was measured to be $\sigma^{\mathrm{Fe}}_{\mathrm{CC}} = (1.28 \pm 0.11({\mathrm{stat.}})^{+0.12}_{-0.11}({\mathrm{syst.}})) \times 10^{-38} \, {\mathrm{cm}}^{2}/{\mathrm{nucleon}}$. The cross section in a limited kinematic phase space of induced muons, $\theta_{\mu} < 45^{\circ}$ and $p_{\mu} > 400 \, {\rm MeV}/c$, on iron was $\sigma^{\mathrm{Fe}}_{\mathrm{CC \hspace{1mm} phase \hspace{0.5mm} space}} = (0.84 \pm 0.07({\mathrm{stat.}})^{+0.07}_{-0.06}({\mathrm{syst.}})) \times 10^{-38} \, {\mathrm{cm}}^{2}/{\mathrm{nucleon}}$. 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.
The Search for Hidden Particles (SHiP) experiment proposal at CERN demands a dedicated dipole magnet for its scattering and neutrino detector. This requires a very large volume to be uniformly ...magnetized at B>1.2 T, with constraints regarding the inner instrumented volume as well as the external region, where no massive structures are allowed and only an extremely low stray field is admitted. In this paper we report the main technical challenges and the relevant design options providing a comprehensive design for the magnet of the SHiP Scattering and Neutrino Detector.
Abstract
Precise neutrino–nucleus interaction measurements in the sub-multi-GeV region are important to reduce the systematic uncertainty in future neutrino oscillation experiments. Furthermore, an ...excess of
${\nu_e}$
interactions, as a possible interpretation of the existence of a sterile neutrino, has been observed in such an energy region. The nuclear emulsion technique can measure all the final state particles with low energy threshold for a variety of targets (Fe, C, H
${_2}$
O, and so on). Its sub-
$\mu$
m position resolution allows measurements of the
${\nu_e}$
cross-section with good electron/gamma separation capability. We started a new experiment at J-PARC to study sub-multi-GeV neutrino interactions by introducing the nuclear emulsion technique. The J-PARC T60 experiment has been implemented as a first step in such a project. Systematic neutrino event analysis with full scanning data in the nuclear emulsion detector was performed for the first time. The first neutrino event detection and its analysis are described in this paper.
Abstract
We describe the first ever implementation of a clock-based, multi-stage emulsion shifter in an accelerator neutrino experiment. The system was installed in the neutrino monitoring building ...at the Japan Proton Accelerator Research Complex as part of a test experiment, T60, and stable operation was maintained for a total of 126.6 days. By applying time information to emulsion films, various results were obtained. Time resolutions of 5.3–14.7 s were evaluated in an operation spanning 46.9 days (yielding division numbers of 1.4–3.8
$\times10^{5}$
). By using timing and spatial information, reconstruction of coincident events consisting of high-multiplicity and vertex-contained events, including neutrino events, was performed. Emulsion events were matched to events observed by INGRID, one of the on-axis near detectors of the T2K experiment, with high reliability (98.5%), and hybrid analysis of the emulsion and INGRID events was established by means of the multi-stage shifter. The results demonstrate that the multi-stage shifter can feasibly be used in neutrino experiments.
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