| This work presents experimental measurements obtained by analyzing the first 254 live days of data from the SNO NaCl run. The electron neutrino flux was measured to be 1.66 ± 0.10 (syst.) × 106cm−2s−l and the non-electron neutrino flux was measured to be 3.32 ± 0.38 (syst.) × 106cm−2s−1. Using the above results we determined the integrated electron neutrino survival probability to be 0.33 ± 0.04 (syst.). This rejects maximum mixing in the solar neutrino sector at more than 3σ using SNO data only under the assumption that the flavor changing mechanism is due to the MSW effect in the solar interior.; The capability of the Sudbury Neutrino Observatory (SNO) to distinguish between the Charged-Current (CC) and Neutral-Current(NC) neutrino interactions made possible the first simultaneous measurements of the electron and non-electron solar neutrino flux, providing a direct test of the hypothesis that neutrinos change flavor as they propagate from the Sun to the Earth. Two tonnes of purified NaCl were added to the one kilotonne of heavy water target of SNO to enhance the neutron capture efficiency and detection of capture gamma-rays. Neutron capture on 35Cl often produces multiple gamma-rays, which permits a statistical separation of neutron capture and electron events based on the event isotropy, the increased statistical separation between event categories, using the degree of event isotropy, made possible a significant improvement on the measured fluxes. Moreover, the flux analysis does not require any assumption regarding the energy dependence of the flavor changing mechanism. |
