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

• Published in: arXiv.org 2019-02
• Main Authors: Abe, K, Ali, A, Antonova, M, Aoki, S, Ariga, A, Barbi, M, Barr, G, Berns, L, Bienstock, S, Boyd, S B, Calcutt, J, Checchia, C, Cherdack, D, Collazuol, G, Coplowe, D, Denner, P F, F Di Lodovico, Drapier, O, Duffy, K E, Ereditato, A, Fujita, R, Gizzarelli, F, Haigh, J T, Hiramoto, A, Hogan, M, N T Hong Van, Hosomi, F, Ikeda, M, Intonti, R A, Ishii, T, Jesus, C, Jiang, M, Johnson, S, Kajita, T, Katori, T, Kato, Y, Kearns, E, Kim, H, King, S, Koch, L, Konaka, A, Lagoda, J, Lamoureux, M, Lawe, M, Longhin, A, Lux, T, Mahn, K, Matsubara, T, Mavrokoridis, K, McFarland, K S, Mezzetto, M, Moriyama, S, Murphy, S, Nakadaira, T, Nakamura, K G, Nakamura, K D, Nakanishi, Y, Nakayoshi, K, Niewczas, K, Nishimura, Y, Nonnenmacher, T S, O'Sullivan, L, Okumura, K, Owen, R A, Oyama, Y, Palladino, V, Pickering, L, Pidcott, C, Pinzon Guerra, E S, Pistillo, C, Porwit, K, Radermacher, T, Radicioni, E, Reinherz-Aronis, E, Rychter, A, Sakashita, K, Sasaki, S, Scott, M, Sekiguchi, T, Shah, R, Sobczyk, J T, Sobel, H, Stewart, T, Stowell, P, Suvorov, S, Sztuc, A A, Tzanov, M, Vasseur, G, Vilela, C, Volkov, V V, Wendell, R, Wilking, M J, Yamamoto, K, Yanagisawa, C, Yasutome, K, Yen, S, Yokoyama, M, Zimmerman, E D, Zsoldos, S, Zykova, A
• Format: Article
• Language: English
• Subjects: Electron-positron pairs; Electrons; Experiments; Kinematics; Neutral currents; Neutrino beams; Neutrinos; Particle physics; Proton accelerators; Quantum theory; Sensors
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1902.03848

Neutrino neutral-current 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 neutral current induced single photon production in this sample. We set the model-dependent upper limit on the cross-section for this process, at 0.114\(\times 10^{-38}\) cm\(^2\) (90\% C.L.) per nucleon, using the J-PARC off-axis neutrino beam with an average energy of \(\left\sim 0.6\) 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.