Event-by-Event Direction Reconstruction of Solar Neutrinos in a High Light-Yield Liquid Scintillator

Kormos, L. L. and O'Keeffe, H. M. (2024) Event-by-Event Direction Reconstruction of Solar Neutrinos in a High Light-Yield Liquid Scintillator. Physical Review D, 109 (7): 072002. ISSN 1550-7998

Text (2309.06341v1)
2309.06341v1.pdf - Submitted Version
Download (451kB)

Abstract

The direction of individual $^8$B solar neutrinos has been reconstructed using the SNO+ 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.