Evidence of Antineutrinos from Distant Reactors Using Pure Water at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>SNO</mml:mi><mml:mo>+</mml:mo></mml:mrow></mml:math>
A. Allega, Mark R. Anderson, S. Andringa, J. Rodrigues Antunes, M. Askins, D. J. Auty, A. Bacon, N. Barros, F. Barão, N. Barros, E. W. Beier, T. S. Bezerra, A. Białek, S. D. Biller, E. Blucher, E. Caden, E. J. Callaghan, S. H. Cheng, M. Chen, B. T. Cleveland, D. Cookman, J. Corning, M. A. Cox, R. Dehghani, J. Deloye, C. Deluce, M. M. Depatie, J. Dittmer, K. H. Dixon, F. Di Lodovico, E. Falk, N. Fatemighomi, R. Ford, K. Frankiewicz, A. Gaur, O. I. González-Reina, D. Gooding, C. Grant, J. E. Grove, A. L. Hallin, D. Hallman, W. J. Heintzelman, R. L. Helmer, Jun Hu, R. Hunt-Stokes, S. Hussain, A. S. Inácio, C. Jillings, S. Kaluzienski, T. Kaptanoglu, P. Khaghani, Hamza Khan, J. Klein, L. L. Kormos, B. Krar, C. Kraus, C. B. Krauss, Tereza Kroupova, I. Lam, Benjamin Land, I. Lawson, L. Lebanowski, J. Lee, C. Lefebvre, J. Lidgard, Yen-Hsun Lin, V. Lozza, M. Luo, A. Maio, S. Manecki, J. Maneira, R. D. Martín, N. McCauley, A. B. McDonald, C. Mills, I. Morton-Blake, S. Naugle, L. J. Nolan, H. M. O’Keeffe, G. D. Orebi Gann, J. Page, William C. Parker, J. Paton, S. J. M. Peeters, L. Pickard, P. Ravi, A. Reichold, S. Riccetto, R. Richardson, M. Rigan, J. Rose, R. Rosero, J. Rumleskie, I. Semenec, P. Skensved, M. Smiley, R. Svoboda, B. Tam, J. C-L. Tseng, E. Turner
Abstract
The SNO+ Collaboration reports the first evidence of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240 km away in Ontario, Canada. This analysis uses events with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods are used to distinguish reactor antineutrinos from background events in 190 days of data and yield consistent evidence for antineutrinos with a combined significance of 3.5σ.