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

Understand

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.