skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Electron energy spectra, fluxes, and day-night asymmetries of {sup 8}B solar neutrinos from measurements with NaCl dissolved in the heavy-water detector at the Sudbury Neutrino Observatory

Abstract

Results are reported from the complete salt phase of the Sudbury Neutrino Observatory experiment in which NaCl was dissolved in the {sup 2}H{sub 2}O (''D{sub 2}O'') target. The addition of salt enhanced the signal from neutron capture as compared to the pure D{sub 2}O detector. By making a statistical separation of charged-current events from other types based on event-isotropy criteria, the effective electron recoil energy spectrum has been extracted. In units of 10{sup 6}cm{sup -2}s{sup -1}, the total flux of active-flavor neutrinos from {sup 8}B decay in the Sun is found to be 4.94{sub -0.21}{sup +0.21}(stat){sub -0.34}{sup +0.38}(syst) and the integral flux of electron neutrinos for an undistorted {sup 8}B spectrum is 1.68{sub -0.06}{sup +0.06}(stat){sub -0.09}{sup +0.08}(syst); the signal from ({nu}{sub x},e) elastic scattering is equivalent to an electron-neutrino flux of 2.35{sub -0.22}{sup +0.22}(stat){sub -0.15}{sup +0.15}(syst). These results are consistent with those expected for neutrino oscillations with the so-called large mixing angle parameters and also with an undistorted spectrum. A search for matter-enhancement effects in the Earth through a possible day-night asymmetry in the charged-current integral rate is consistent with no asymmetry. Including results from other experiments, the best-fit values for two-neutrino mixing parameters are {delta}m{sup 2}=(8.0{sub -0.4}{sup +0.6})x10{sup -5}more » eV{sup 2} and {theta}=33.9{sub -2.2}{sup +2.4} degrees.« less

Authors:
; ; ; ; ; ; ;  [1]; ; ; ; ; ; ; ; ; ; ; ;  [2]
  1. Department of Physics and Astronomy, Laurentian University, Sudbury, Ontario, P3E 2C6 (Canada)
  2. Department of Physics, Queen's University, Kingston, Ontario, K7L 3N6 (Canada) [and others
Publication Date:
OSTI Identifier:
20699143
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 72; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevC.72.055502; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA). SNO Collaboration
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ASYMMETRY; BORON 8; CAPTURE; CHARGED CURRENTS; COSMIC NEUTRINOS; ELASTIC SCATTERING; ELECTRON NEUTRINOS; ELECTRONS; ENERGY SPECTRA; HEAVY WATER; ISOTROPY; NEUTRINO DETECTION; NEUTRINO OSCILLATION; NEUTRINO-ELECTRON INTERACTIONS; NEUTRON REACTIONS; NUCLEAR DECAY; SODIUM CHLORIDES; SOLAR NEUTRINOS; SUDBURY NEUTRINO OBSERVATORY; WEINBERG ANGLE

Citation Formats

Aharmim, B., Fleurot, F., Hallman, E.D., Krueger, A., Luoma, S., Schwendener, M.H., Tafirout, Virtue, C.J.R., Ahmed, S.N., Chen, M., Duncan, F.A., Earle, E.D., Evans, H.C., Ewan, G.T., Fulsom, B.G., Graham, K., Hallin, A.L., Handler, W.B., Harvey, P.J., and Howard, C. Electron energy spectra, fluxes, and day-night asymmetries of {sup 8}B solar neutrinos from measurements with NaCl dissolved in the heavy-water detector at the Sudbury Neutrino Observatory. United States: N. p., 2005. Web. doi:10.1103/PhysRevC.72.055502.
Aharmim, B., Fleurot, F., Hallman, E.D., Krueger, A., Luoma, S., Schwendener, M.H., Tafirout, Virtue, C.J.R., Ahmed, S.N., Chen, M., Duncan, F.A., Earle, E.D., Evans, H.C., Ewan, G.T., Fulsom, B.G., Graham, K., Hallin, A.L., Handler, W.B., Harvey, P.J., & Howard, C. Electron energy spectra, fluxes, and day-night asymmetries of {sup 8}B solar neutrinos from measurements with NaCl dissolved in the heavy-water detector at the Sudbury Neutrino Observatory. United States. doi:10.1103/PhysRevC.72.055502.
Aharmim, B., Fleurot, F., Hallman, E.D., Krueger, A., Luoma, S., Schwendener, M.H., Tafirout, Virtue, C.J.R., Ahmed, S.N., Chen, M., Duncan, F.A., Earle, E.D., Evans, H.C., Ewan, G.T., Fulsom, B.G., Graham, K., Hallin, A.L., Handler, W.B., Harvey, P.J., and Howard, C. Tue . "Electron energy spectra, fluxes, and day-night asymmetries of {sup 8}B solar neutrinos from measurements with NaCl dissolved in the heavy-water detector at the Sudbury Neutrino Observatory". United States. doi:10.1103/PhysRevC.72.055502.
@article{osti_20699143,
title = {Electron energy spectra, fluxes, and day-night asymmetries of {sup 8}B solar neutrinos from measurements with NaCl dissolved in the heavy-water detector at the Sudbury Neutrino Observatory},
author = {Aharmim, B. and Fleurot, F. and Hallman, E.D. and Krueger, A. and Luoma, S. and Schwendener, M.H. and Tafirout and Virtue, C.J.R. and Ahmed, S.N. and Chen, M. and Duncan, F.A. and Earle, E.D. and Evans, H.C. and Ewan, G.T. and Fulsom, B.G. and Graham, K. and Hallin, A.L. and Handler, W.B. and Harvey, P.J. and Howard, C.},
abstractNote = {Results are reported from the complete salt phase of the Sudbury Neutrino Observatory experiment in which NaCl was dissolved in the {sup 2}H{sub 2}O (''D{sub 2}O'') target. The addition of salt enhanced the signal from neutron capture as compared to the pure D{sub 2}O detector. By making a statistical separation of charged-current events from other types based on event-isotropy criteria, the effective electron recoil energy spectrum has been extracted. In units of 10{sup 6}cm{sup -2}s{sup -1}, the total flux of active-flavor neutrinos from {sup 8}B decay in the Sun is found to be 4.94{sub -0.21}{sup +0.21}(stat){sub -0.34}{sup +0.38}(syst) and the integral flux of electron neutrinos for an undistorted {sup 8}B spectrum is 1.68{sub -0.06}{sup +0.06}(stat){sub -0.09}{sup +0.08}(syst); the signal from ({nu}{sub x},e) elastic scattering is equivalent to an electron-neutrino flux of 2.35{sub -0.22}{sup +0.22}(stat){sub -0.15}{sup +0.15}(syst). These results are consistent with those expected for neutrino oscillations with the so-called large mixing angle parameters and also with an undistorted spectrum. A search for matter-enhancement effects in the Earth through a possible day-night asymmetry in the charged-current integral rate is consistent with no asymmetry. Including results from other experiments, the best-fit values for two-neutrino mixing parameters are {delta}m{sup 2}=(8.0{sub -0.4}{sup +0.6})x10{sup -5} eV{sup 2} and {theta}=33.9{sub -2.2}{sup +2.4} degrees.},
doi = {10.1103/PhysRevC.72.055502},
journal = {Physical Review. C, Nuclear Physics},
number = 5,
volume = 72,
place = {United States},
year = {Tue Nov 01 00:00:00 EST 2005},
month = {Tue Nov 01 00:00:00 EST 2005}
}