Measurement of the 8B solar neutrino flux using the full sno+ water phase

TheSNO+detector operated initially as a water Cherenkov detector. The implementation of a sealed cover gas system midway through water data taking resulted in a significant reduction in the activity of222Rndaughters in the detector and allowed the lowest background to the solar electron scattering signal above 5 MeV achieved to date. This paper reports an updatedSNO+water phase8Bsolar neutrino analysis with a total livetime of 282.4 days and an analysis threshold of 3.5 MeV. The8Bsolar neutrino flux is found to be(2.3⁢2+0.18−0.17⁢(stat)+0.07−0.05⁢(syst))×106 cm−2 s−1assuming no neutrino oscillations, or(5.3⁢6+0.41−0.39⁢(stat)+0.17−0.16⁢(syst))×106 cm−2 s−1assuming 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.