First demonstration of emulsion multi-stage shifter for accelerator neutrino experiment in J-PARC T60

TL;DR

This paper reports the first successful implementation of an emulsion multi-stage shifter in an accelerator neutrino experiment, demonstrating its stable operation, precise timing, and effective event reconstruction capabilities over several months.

Contribution

It introduces a novel emulsion multi-stage shifter system for neutrino experiments, showing its feasibility and high reliability in event timing and reconstruction.

Findings

Achieved time resolutions of 5.3 to 14.7 seconds.

Matched emulsion events with near detector data at 98.5% reliability.

Demonstrated stable operation over 126.6 days.

Abstract

We describe the first ever implementation of an emulsion multi-stage shifter in an accelerator neutrino experiment. The system was installed in the neutrino monitor building in J-PARC as a 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 to 14.7 s were evaluated in an operation spanning 46.9 days (time resolved numbers of 3.8--1.4$\times10^{5}$). By using timing and spatial information, a reconstruction of coincident events that consisted of high multiplicity events and vertex events, including neutrino events was performed. Emulsion events were matched to events observed by INGRID, one of near detectors of the T2K experiment, with high reliability (98.5\%) and hybrid analysis was established via use of the multi-stage shifter. The results demonstrate that the multi-stage shifter is feasible for use in neutrino experiments.