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, G.J.Barr, G.Barry, C.Batkiewicz-Kwasniak, M.Karlen, Deanet al.2021-05-102021-05-1020192019Abe, K., Akutsu, R., Ali, A., Andreopoulos, C., Anthony, L., Karlen, D., … Zykova, A. (2019). Search for neutral-current induced single photon production at the ND280 near detector in T2K. Journal of Physics G: Nuclear and Particle Physics, 46, 1-16. https://doi.org/10.1088/1361-6471/ab227d.https://doi.org/10.1088/1361-6471/ab227dhttp://hdl.handle.net/1828/12960Neutrino neutral-current (NC) induced single photon production is a sub-leading 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 fine-grained 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 $5.738\times {10}^{20}$ 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 $0.114\times {10}^{-38}$ cm2 (90% C.L.) per nucleon, using the J-PARC off-axis neutrino beam with an average energy of $\left\langle {E}_{\nu }\right\rangle \sim 0.6$ 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.enArticleDepartment of Physics and Astronomy