Search for neutral-current induced single photon production at the ND280 near detector in T2K

All rights reserved. Neutrino neutral-current (NC) induced single photon production is a subleading order process for accelerator-based neutrino beam experiments including T2K. It is, however, an important process to understand because it is a background for electron (anti)neutrino appearance oscill...

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Bibliographic Details
Main Authors: Abe, K, Akutsu, R, Ali, A, Andreopoulos, C, Anthony, L, Antonova, M, Aoki, S, Ariga, A, Ashida, Y, Awataguchi, Y, Azuma, Y, Ban, S, Barbi, M, Barker, GJ, Barr, G, Barry, C, Batkiewicz-Kwasniak, M, Bench, F, Berardi, V, Berkman, S, Berner, RM, Berns, L, Bhadra, S, Bienstock, S, Blondel, A
Format: Journal article
Published: IOP Publishing 2019
Description
Summary:All rights reserved. Neutrino neutral-current (NC) induced single photon production is a subleading order process for accelerator-based neutrino beam experiments including T2K. It is, however, an important process to understand because it is a background for electron (anti)neutrino appearance oscillation experiments. Here, we performed the first search of this process below 1 GeV using the finegrained detector at the T2K ND280 off-axis near detector. By reconstructing single photon kinematics from electron positron pairs, we achieved 95% pure gamma ray sample from 5.738 1020 protons-on-targets neutrino mode data. We do not find positive evidence of NC induced single photon production in this sample. We set the model-dependent upper limit on the cross-section for this process, at 0.114 10-38 cm2 (90% C.L.) per nucleon, using the J-PARC off-axis neutrino beam with an average energy of .En. ~ 0.6 GeV. This is the first limit on this process below 1.GeV which is important for current and future oscillation experiments looking for electron neutrino appearance oscillation signals.