Event-by-event direction reconstruction of solar neutrinos in a high light-yield liquid scintillator
A. Allega, Mark R. Anderson, S. Andringa, J. Rodrigues Antunes, M. Askins, D. J. Auty, A. Bacon, Joy Don Baker, N. Barros, F. Barão, R. Bayes, E. W. Beier, T. S. Bezerra, A. Białek, S. D. Biller, E. Blucher, E. Caden, E. J. Callaghan, M. Chen, S. H. Cheng, B. T. Cleveland, D. Cookman, J. Corning, M. A. Cox, R. Dehghani, J. Deloye, M. M. Depatie, F. Di Lodovico, J. Dittmer, K. H. Dixon, E. Falk, N. Fatemighomi, R. Ford, A. Gaur, O. I. González-Reina, D. Gooding, C. Grant, J. E. Grove, S. Hall, A. L. Hallin, W. J. Heintzelman, R. L. Helmer, C. Hewitt, B. Hreljac, Virginia J. Howard, Jun Hu, R. Hunt-Stokes, Safeer Hussain, A. S. Inácio, C. Jillings, S. Kaluzienski, T. Kaptanoglu, P. Khaghani, Hamza Khan, J. R. Klein, L. L. Kormos, B. Krar, C. Kraus, C. B. Krauss, Tereza Kroupova, C. Raymond Lake, L. Lebanowski, J. Lee, C. Lefebvre, Yen-Hsun Lin, V. Lozza, M. Luo, A. Maio, S. Manecki, J. Maneira, R. D. Martin, N. McCauley, A. B. McDonald, C. Mills, G.M. Milton, I. Morton-Blake, Muhammad Mubasher, A. Molina Colina, Daniel A. Morris, S. Naugle, L. J. Nolan, H. M. O’Keeffe, G. D. Orebi Gann, J. Page, K. Paleshi, William C. Parker, J. Paton, S. J. M. Peeters, L. Pickard, P. Ravi, A. Reichold, S. Riccetto, M. Rigan, J. Rose, R. Rosero, J. Rumleskie, I. Semenec, P. Skensved, M. Smiley, J. D. Smith
Abstract
The direction of individual <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mmultiscripts><a:mrow><a:mi mathvariant="normal">B</a:mi></a:mrow><a:mprescripts/><a:none/><a:mrow><a:mn>8</a:mn></a:mrow></a:mmultiscripts></a:mrow></a:math> solar neutrinos has been reconstructed using the <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:mrow><d:mi>SNO</d:mi><d:mo>+</d:mo></d:mrow></d:math> liquid scintillator detector. Prompt, directional Cherenkov light was separated from the slower, isotropic scintillation light using time information, and a maximum likelihood method was used to reconstruct the direction of individual scattered electrons. A clear directional signal was observed, correlated with the solar angle. The observation was aided by a period of low primary fluor concentration that resulted in a slower scintillator decay time. This is the first time that event-by-event direction reconstruction in high light-yield liquid scintillator has been demonstrated in a large-scale detector. Published by the American Physical Society 2024