| The Sudbury Neutrino Observatory, through its measurements of the solar 8B neutrino flux via the charged current (CC) and neutral current (NC) interactions, has successfully demonstrated that solar electron neutrinos undergo flavor transformation enroute to Earth. This work presents a measurement of the 8B neutrino flux combining the pure D2O (283 days) and the salt phases (391 days) of data using an energy threshold of 4.0 MeV. The measured CC flux, which is sensitive only to electron neutrinos, is 1.67+0.04-0.04stat. +0.10-0.07 (syst.) × 106cm-2s-1 and the NC flux, sensitive to all active neutrino flavors, is 4.98+0.17-0.16stat. +0.20-0.26 (syst.) × 106cm-2s-1. While the measured NC flux agrees with the flux predicted by the Standard Solar Model, the CC flux is strongly suppressed. These results are consistent with the prediction of matter enhanced neutrino oscillations (MSW) with a large mixing angle (LMA).;The measured fluxes were determined without assumptions about the energy spectrum of the neutrinos interacting via the CC and elastic scattering (ES) interactions. This work presents the extracted CC and ES energy spectra at an energy threshold of 4.0 MeV and finds that both spectra are consistent with an undistorted 8B neutrino energy spectrum. |
