Search for invisible modes of nucleon decay in water with the SNO+ detector

This paper reports results from a search for nucleon decay through invisible modes, where no visible energy is directly deposited during the decay itself, during the initial water phase of SNO+. However, such decays within the oxygen nucleus would produce an excited daughter that would subsequently deexcite, often emitting detectable gamma rays. A search for such gamma rays yields limits of 2.5×1029  y at 90% Bayesian credibility level (with a prior uniform in rate) for the partial lifetime of the neutron, and 3.6×1029  y for the partial lifetime of the proton, the latter a 70% improvement on the previous limit from SNO. We also present partial lifetime limits for invisible dinucleon modes of 1.3×1028  y for nn, 2.6×1028  y for pn and 4.7×1028  y for pp, an improvement over existing limits by close to 3 orders of magnitude for the latter two

Measurement of Reactor Antineutrino Oscillation at SNO.

SNO+ Collaboration reports its second spectral analysis of reactor antineutrino oscillation using 286 ton-yr of new data. The measured energies of reactor antineutrino candidates were fitted to obtain the second-most precise determination of the neutrino mass-squared difference Δm_{21}^{2}=(7.96_{-0.42}^{+0.48})×10^{-5}  eV^{2}. Constraining Δm_{21}^{2} and sin^{2}θ_{12} with measurements from long-baseline reactor antineutrino and solar neutrino experiments yields Δm_{21}^{2}=(7.58_{-0.17}^{+0.18})×10^{-5}  eV^{2} and sin^{2}θ_{12}=0.308±0.013. This fit also yields a first measurement of the flux of geoneutrinos in the Western Hemisphere, with 73_{-43}^{+47} TNU at SNO+

Measurement of reactor antineutrino oscillation at SNO+

SNO+ Collaboration reports its second spectral analysis of reactor antineutrino oscillation using 286 ton-yr of new data. The measured energies of reactor antineutrino candidates were fitted to obtain the second-most precise determination of the neutrino mass-squared difference Δm212=(7.96−0.42+0.48)×10−5  eV2. Constraining Δm212 and sin2θ12 with measurements from long-baseline reactor antineutrino and solar neutrino experiments yields Δm212=(7.58−0.17+0.18)×10−5  eV2 and sin2θ12=0.308±0.013. This fit also yields a first measurement of the flux of geoneutrinos in the Western Hemisphere, with 73−43+47 TNU at SNO+.</p