The Sudbury Neutrino Observatory (SNO) used an array of $^{3}\mathrm{He}$ proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (${\ensuremath{\nu}}_{x}$) $^{8}\mathrm{B}$ solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be ${5.54}_{\ensuremath{-}0.31}^{+0.33}(\mathrm{\text{stat}}{)}_{\ensuremath{-}0.34}^{+0.36}(\mathrm{\text{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{6}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$, in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields $\ensuremath{\Delta}{m}^{2}={7.59}_{\ensuremath{-}0.21}^{+0.19}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}\text{ }\text{ }{\mathrm{eV}}^{2}$ and $\ensuremath{\theta}={34.4}_{\ensuremath{-}1.2}^{+1.3}$ degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.
Independent Measurement of the Total ActiveB8Solar Neutrino Flux Using an Array ofHe3Proportional Counters at the Sudbury Neutrino Observatory | Litlas
