Pulse shape discrimination in JSNS

Dodo, Taku; Haga, Katsuhiro  ; Harada, Masahide   ; Hasegawa, Shoichi   ; Kasugai, Yoshimi  ; Kinoshita, Hidetaka   ; Masuda, Shiho; Meigo, Shinichiro   ; Sakai, Kenji ; Suzuya, Kentaro; Yamaguchi, Yuji   ; 43 of others*

JSNS (J-PARC Sterile Neutrino Search a t J-PARC Spallation Neutron Source) is an experiment that is searching for sterile neutrinos via the observation of appearance oscillations using neutrinos from muon decay-at-rest. For this search, rejecting cosmic-ray-induced neutron events by Pulse Shape Discrimination (PSD) is essential because the JSNS detector is located above ground, on the third floor of the building. We have achieved 94.95 rejection of neutron events while keeping 92.82 of signal, electron-like events using a data-driven likelihood method. This article will report the PSD technique using the full fiducial volume of the JSNS detector.