Observations of neutral-current $\nu$ interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current (NC), elastic scattering, and charged current reactions and assuming the standard ${}^8\mathrm{B}$ shape, the ${\nu }_e$ component of the ${}^8\mathrm{B}$ solar flux is ${\phi }_e{=1.76\mathrm{}}_{-0.05\mathrm{}}^{+0.05\mathrm{}}\left(\mathrm{stat}{)}_{-0.09\mathrm{}}^{+0.09\mathrm{}}\right(\mathrm{syst})\times {10}^6{\mathrm{cm}}^{-2\mathrm{}}{\mathrm{s}}^{-1\mathrm{}}$ for a kinetic energy threshold of 5 MeV. The non- ${\nu }_e$ component is ${\phi }_{\mu \tau }{=3.41\mathrm{}}_{-0.45\mathrm{}}^{+0.45\mathrm{}}\left(\mathrm{stat}{)}_{-0.45\mathrm{}}^{+0.48\mathrm{}}\right(\mathrm{syst})\times {10}^6{\mathrm{cm}}^{-2\mathrm{}}{\mathrm{s}}^{-1\mathrm{}}$, $5.3\sigma$ greater than zero, providing strong evidence for solar ${\nu }_e$ flavor transformation. The total flux measured with the NC reaction is ${\phi }_{\mathrm{NC}}{=5.09\mathrm{}}_{-0.43\mathrm{}}^{+0.44\mathrm{}}\left(\mathrm{stat}{)}_{-0.43\mathrm{}}^{+0.46\mathrm{}}\right(\mathrm{syst})\times {10}^6{\mathrm{cm}}^{-2\mathrm{}}{\mathrm{s}}^{-1\mathrm{}}$, consistent with solar models.

The Daya Bay Reactor Neutrino Experiment has measured a nonzero value for the neutrino mixing angle ${\theta }_{13}$ with a significance of 5.2 standard deviations. Antineutrinos from six 2.9 $\mathrm{G}{\mathrm{W}}_{\mathrm{th}}$ reactors were detected in six antineutrino detectors deployed in two near (flux-weighted baseline 470 m and 576 m) and one far (1648 m) underground experimental halls. With a $43000\mathrm{ton}–\mathrm{G}{\mathrm{W}}_{\mathrm{th}}–\mathrm{day}$ live-time exposure in 55 days, 10 416 (80 376) electron-antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to expected number of antineutrinos at the far hall is $R=0.940\pm 0.011(\mathrm{stat}.)\pm 0.004(\mathrm{syst}.)$. A rate-only analysis finds ${sin}^{2}2{\theta }_{13}=0.092\pm 0.016(\mathrm{stat}.)\pm 0.005(\mathrm{syst}.)$ in a three-neutrino framework.

Solar neutrinos from ${}^8\mathrm{B}$ decay have been detected at the Sudbury Neutrino Observatory via the charged current (CC) reaction on deuterium and the elastic scattering (ES) of electrons. The flux of ${\nu }_e$’s is measured by the CC reaction rate to be ${\phi }^{\mathrm{CC}}\left({\nu }_e\right)=1.75\mathrm{}\pm 0.07\left(\mathrm{stat}{)}_{-0.11\mathrm{}}^{+0.12\mathrm{}}\right(\mathrm{syst})\pm 0.05(\mathrm{theor})\times {10}^6{\mathrm{cm}}^{-2\mathrm{}}{\mathrm{s}}^{-1\mathrm{}}$. Comparison of ${\phi }^{\mathrm{CC}}\left({\nu }_e\right)$ to the Super-Kamiokande Collaboration’s precision value of the flux inferred from the ES reaction yields a $3.3\sigma$ difference, assuming the systematic uncertainties are normally distributed, providing evidence of an active non- ${\nu }_e$ component in the solar flux. The total flux of active ${}^8\mathrm{B}$ neutrinos is determined to be $5.44\pm 0.99\times {10}^6{\mathrm{cm}}^{-2\mathrm{}}{\mathrm{s}}^{-1\mathrm{}}$.

The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted ${}^8\mathrm{B}$ spectrum, the night minus day rate is $14.0\%\pm 6.3{\%}_{-1.4\mathrm{}}^{+1.5\mathrm{}}\%$ of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the ${\nu }_e$ asymmetry is found to be $7.0\%\pm 4.9{\%}_{-1.2\mathrm{}}^{+1.3\mathrm{}}\%$. A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution.

The Sudbury Neutrino Observatory has precisely determined the total active (${\nu }_x$) ${}^8\mathrm{B}$ solar neutrino flux without assumptions about the energy dependence of the ${\nu }_e$ survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be $5.21\pm 0.27\mathrm{(}\mathrm{stat}\mathrm{)}\pm 0.38\mathrm{(}\mathrm{syst}\mathrm{)}\times {10}^6{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$, in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields $\Delta m^2={7.1}_{-0.6}^{+1.2}\times {10}^{-5}{\mathrm{eV}}^2$ and $\theta ={32.5}_{-2.3}^{+2.4}$ degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

We report results from a combined analysis of solar neutrino data from all phases of the Sudbury Neutrino Observatory (SNO). By exploiting particle identification information obtained from the proportional counters installed during the third phase, this analysis improved background rejection in that phase of the experiment. The combined analysis of the SNO data resulted in a total flux of active neutrino flavors from ${}^8\mathrm{B}$ decays in the Sun of $(5.25\pm 0.16{(\mathrm{stat}.)}_{-0.13}^{+0.11}(\mathrm{syst}.))\times {10}^6{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$, while a two-flavor neutrino oscillation analysis yielded $\Delta m_{21}^2=(5.6_{-1.4}^{+1.9})\times {10}^{-5}{\mathrm{eV}}^2$ and ${\tan }^2{\theta }_{12}=0.{427}_{-0.029}^{+0.033}$. A three-flavor neutrino oscillation analysis combining the SNO result with results of all other solar neutrino experiments and reactor neutrino experiments yielded $\Delta m_{21}^2=(7.{46}_{-0.19}^{+0.20})\times {10}^{-5}{\mathrm{eV}}^2$, ${\tan }^2{\theta }_{12}=0.{443}_{-0.025}^{+0.030}$, and ${\sin }^2{\theta }_{13}=(2.{49}_{-0.32}^{+0.20})\times {10}^{-2}$.