The direction of individual B 8 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. Published by the American Physical Society 2024
The SNO+ collaboration reports its first spectral analysis of long-baseline
reactor antineutrino oscillation using 114 tonne-years of data. Fitting the
neutrino oscillation probability to the ...observed energy spectrum yields
constraints on the neutrino mass-squared difference $\Delta m^2_{21}$. In the
ranges allowed by previous measurements, the best-fit $\Delta m^2_{21}$ is
(8.85$^{+1.10}_{-1.33}$) $\times$ 10$^{-5}$ eV$^2$. This measurement is
continuing in the next phases of SNO+ and is expected to surpass the present
global precision on $\Delta m^2_{21}$ with about three years of data.
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.
