Direct evidence for neutrino flavor transformation from neutral-current interactions in the Sudbury Neutrino Observatory -: art. no. 011301

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 B-8 shape, the nu(e) component of the B-8 solar flux is phi(e)=1.76(-0.05)(+0.05)( stat)(+0.09)(-0.09)( syst)x10(6) cm(-2) s(-1) for a kinetic energy threshold of 5 MeV. The non-nu(e) component is phi(mutau)=3.41(+0.45) (-0.45)(stat)(+0.48) (-0.45)(syst)x10(6) cm(-2) s(-1) , 5.3sigma greater than zero, providing strong evidence for solar nu(e) flavor transformation. The total flux measured with the NC reaction is phi(NC)=5.09(-0.43)(+0.44) (stat)(+0.46)(-0.43) (syst)x10(6) cm (-2) s (-1) , consistent with solar models.