Study on the accidental background of the JSNS${}^2$ experiment

Abstract

JSNS${}^2$ (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment which searches for sterile neutrinos via the observation of $\bar{\hat{I}}{½}_{\hat{I}}¼\to \bar{\hat{I}}{½}_e$ appearance oscillations using muon decay-at-rest neutrinos. The data taking of JSNS${}^2$ have been performed from 2021. In this manuscript, a study of the accidental background is presented. The rate of the accidental background is (9.29$\pm 0.39)\times 10^{-8}$ / spill with 0.75 MW beam power and comparable to the number of searching signals.

arXiv admin note: substantial text overlap with arXiv:2111.07482