Published April 2003 | Version v1
Journal article

Neutral current and day night measurements from the pure D2O phase of SNO

Description

The Sudbury Neutrino Observatory is a 1000 T D2O Cerenkov detector that is sensitive to 8B solar neutrinos. The energy, radius, and direction with respect to the sun is measured for each neutrino event; these distributions are used to separately determine the rates of the charged current, neutral current and electron scattering reactions of neutrinos on deuterium. Assuming an undistorted 8B spectrum, the νe component of the 8B solar flux is phie = 1.76+0.05-0.05(stat.)+0.09-0.09 (syst.) x 106 cm-2s-1 based on events with a measured kinetic energy above 5 MeV. The non-νe component is phiμτ 3.41+0.45-0.45(stat.)+0.48-0.45 (syst.) x 106 cm-2s-1, 5.3σ greater than zero, providing strong evidence for solar νe flavor transformation. The total flux measured with the NC reaction is phiNC = 5.09+0.044-0.43(stat.)+0.46-0.43 (sy st.) x 106 cm-2s-1, consistent with solar models. The night minus day rate is 14.0% ± 6.3%+1.5-1.4% of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the νe asymmetry is found to be 7.0% ± 4.9%+1.3-1.2%. A global solar neutrino analysis is terms of matter-enhanced oscillations of two active flavors strongly favors the Large Mixing Angle (LMA) solution

Additional details

Identifiers

PII
S0920563203012982;

Publishing Information

Journal Title
Nuclear Physics. B, Proceedings Supplements
Journal Volume
118
Journal Issue
3
Journal Page Range
p. 3-14
ISSN
0920-5632
CODEN
NPBSE7

Conference

Title
20. international conference on neutrino physics and astrophysics
Dates
25-30 May 2002
Place
Munich (Germany)

Optional Information

Copyright
Copyright (c) 2003 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.