First Neutrino Observations from the Sudbury Neutrino Observatory [chapter]

David Sinclair
2001 Dark Matter in Astro- and Particle Physics  
The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D 2 O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar ν e flux and the total flux of all active neutrino species. Solar neutrinos from the decay of 8 B have been detected at SNO by the charged-current (CC) interaction on the deuteron and by the elastic scattering (ES) of electrons.
more » ... ) of electrons. While the CC reaction is sensitive exclusively to ν e , the ES reaction also has a small sensitivity to ν µ and ν τ . In this paper, recent solar neutrino results from the SNO experiment are presented. It is demonstrated that the solar flux from 8 B decay as measured from the ES reaction rate under the no-oscillation assumption is consistent with the high precision ES measurement by the Super-Kamiokande experiment. The ν e flux deduced from the CC reaction rate in SNO differs from the Super-Kamiokande ES results by 3.3σ . This is evidence for an active neutrino component, in additional to ν e , in the solar neutrino flux. These results also allow the first experimental determination of the total active 8 B neutrino flux from the Sun, and is found to be in good agreement with solar model predictions.
doi:10.1007/978-3-642-56643-1_44 fatcat:hh7fx7ljnbbrbmdqrhihnvjpxi