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