Measurement of the ${}^8$B Solar Neutrino Flux Using the Full SNO+ Water Phase Dataset

Abstract

The SNO+ detector operated initially as a water Cherenkov detector. The implementation of a sealed covergas system midway through water data taking resulted in a significant reduction in the activity of ${}^{222}$Rn daughters in the detector and allowed the lowest background to the solar electron scattering signal above 5 MeV achieved to date. This paper reports an updated SNO+ water phase ${}^8$B solar neutrino analysis with a total livetime of 282.4 days and an analysis threshold of 3.5 MeV. The ${}^8$B solar neutrino flux is found to be $\left(2.32_{-0.17}^{+0.18}{\text{(stat.)}}_{-0.05}^{+0.07}\text{(syst.)}\right)\times 10^6$ cm${}^{-2}$s${}^{-1}$ assuming no neutrino oscillations, or $\left(5.36_{-0.39}^{+0.41}{\text{(stat.)}}_{-0.16}^{+0.17}\text{(syst.)}\right)\times 10^6$ cm${}^{-2}$s${}^{-1}$ assuming standard neutrino oscillation parameters, in good agreement with both previous measurements and Standard Solar Model Calculations. The electron recoil spectrum is presented above 3.5 MeV.

arXiv comment9 pages, 10 figures, v2: minor updates to match PRD publication

References in corpus (20)

• Measurement of the Total Active 8B Solar Neutrino Flux at the Sudbury Neutrino Observatory with Enhanced Neutral Current Sensitivity
• New solar opacities, abundances, helioseismology, and neutrino fluxes
• Electron Energy Spectra, Fluxes, and Day-Night Asymmetries of ${}^8$B Solar Neutrinos from the 391-Day Salt Phase SNO Data Set
• The Sudbury Neutrino Observatory
• Combined Analysis of all Three Phases of Solar Neutrino Data from the Sudbury Neutrino Observatory
• Measurement of the solar 8B neutrino rate with a liquid scintillator target and 3 MeV energy threshold in the Borexino detector
• Neutrino masses and mixings: Status of known and unknown $3\nu$ parameters
• The SNO+ Experiment
• Updated determination of the solar neutrino fluxes from solar neutrino data
• Measurement of the 8B Solar Neutrino Flux with the KamLAND Liquid Scintillator Detector
• The ${}^8$B Neutrino Spectrum
• Search for invisible modes of nucleon decay in water with the SNO+ detector
• Solar neutrino measurements using the full data period of Super-Kamiokande-IV
• Measurement of the ${}^8$B Solar Neutrino Flux in SNO+ with Very Low Backgrounds
• Solar Neutrino Spectroscopy
• Improved search for invisible modes of nucleon decay in water with the SNO+ detector
• Evidence of Antineutrinos from Distant Reactors using Pure Water at SNO+
• Status of Direct Determination of Solar Neutrino Fluxes after Borexino
• Measurement of neutron-proton capture in the SNO+ water phase
• Optical calibration of the SNO+ detector in the water phase with deployed sources

Cited by in corpus (1)

• New Spallation Background Rejection Techniques to Greatly Improve the Solar Neutrino Sensitivity of JUNO