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Title: Determination of the {nu}{sub e} and total {sup 8}B solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set

Abstract

This article provides the complete description of results from the Phase I data set of the Sudbury Neutrino Observatory (SNO). The Phase I data set is based on a 0.65 kiloton-year exposure of {sup 2}H{sub 2}O (in the following denoted as D{sub 2}O) to the solar {sup 8}B neutrino flux. Included here are details of the SNO physics and detector model, evaluations of systematic uncertainties, and estimates of backgrounds. Also discussed are SNO's approach to statistical extraction of the signals from the three neutrino reactions (charged current, neutral current, and elastic scattering) and the results of a search for a day-night asymmetry in the {nu}{sub e} flux. Under the assumption that the {sup 8}B spectrum is undistorted, the measurements from this phase yield a solar {nu}{sub e} flux of {phi}({nu}{sub e})=1.76{sub -0.05}{sup +0.05}(stat.){sub -0.09}{sup +0.09}(syst.)x10{sup 6} cm{sup -2} s{sup -1} and a non-{nu}{sub e} component of {phi}({nu}{sub {mu}}{sub {tau}})=3.41{sub -0.45}{sup +0.45}(stat.){sub -0.45}{sup +0.48}(syst.)x10{sup 6} cm{sup -2} s{sup -1}. The sum of these components provides a total flux in excellent agreement with the predictions of standard solar models. The day-night asymmetry in the {nu}{sub e} flux is found to be A{sub e}=7.0{+-}4.9(stat.){sub -1.2}{sup +1.3}%(syst.), when the asymmetry in the total fluxmore » is constrained to be zero.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1]; ; ; ;  [2]
  1. Department of Physics and Astronomy, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada)
  2. Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, Washington 98195 (United States) (and others)
Publication Date:
OSTI Identifier:
20995235
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevC.75.045502; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; BORON 8; ELECTRON NEUTRINOS; HEAVY WATER; NEUTRINO REACTIONS; SOLAR NEUTRINOS; STAR MODELS; SUDBURY NEUTRINO OBSERVATORY

Citation Formats

Aharmim, B., Bigu, J., Cowan, J. H. M., Farine, J., Fleurot, F., Hallman, E. D., Haq, R. U., Hewett, J., Hykaway, J. G., Krueger, A., Luoma, S., Roberge, A., Saettler, E., Schwendener, M. H., Tafirout, R., Virtue, C. J., Ahmad, Q. R., Bullard, T. V., Burritt, T. H., and Cox, G. A. Determination of the {nu}{sub e} and total {sup 8}B solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set. United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.045502.
Aharmim, B., Bigu, J., Cowan, J. H. M., Farine, J., Fleurot, F., Hallman, E. D., Haq, R. U., Hewett, J., Hykaway, J. G., Krueger, A., Luoma, S., Roberge, A., Saettler, E., Schwendener, M. H., Tafirout, R., Virtue, C. J., Ahmad, Q. R., Bullard, T. V., Burritt, T. H., & Cox, G. A. Determination of the {nu}{sub e} and total {sup 8}B solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set. United States. doi:10.1103/PHYSREVC.75.045502.
Aharmim, B., Bigu, J., Cowan, J. H. M., Farine, J., Fleurot, F., Hallman, E. D., Haq, R. U., Hewett, J., Hykaway, J. G., Krueger, A., Luoma, S., Roberge, A., Saettler, E., Schwendener, M. H., Tafirout, R., Virtue, C. J., Ahmad, Q. R., Bullard, T. V., Burritt, T. H., and Cox, G. A. Sun . "Determination of the {nu}{sub e} and total {sup 8}B solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set". United States. doi:10.1103/PHYSREVC.75.045502.
@article{osti_20995235,
title = {Determination of the {nu}{sub e} and total {sup 8}B solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set},
author = {Aharmim, B. and Bigu, J. and Cowan, J. H. M. and Farine, J. and Fleurot, F. and Hallman, E. D. and Haq, R. U. and Hewett, J. and Hykaway, J. G. and Krueger, A. and Luoma, S. and Roberge, A. and Saettler, E. and Schwendener, M. H. and Tafirout, R. and Virtue, C. J. and Ahmad, Q. R. and Bullard, T. V. and Burritt, T. H. and Cox, G. A.},
abstractNote = {This article provides the complete description of results from the Phase I data set of the Sudbury Neutrino Observatory (SNO). The Phase I data set is based on a 0.65 kiloton-year exposure of {sup 2}H{sub 2}O (in the following denoted as D{sub 2}O) to the solar {sup 8}B neutrino flux. Included here are details of the SNO physics and detector model, evaluations of systematic uncertainties, and estimates of backgrounds. Also discussed are SNO's approach to statistical extraction of the signals from the three neutrino reactions (charged current, neutral current, and elastic scattering) and the results of a search for a day-night asymmetry in the {nu}{sub e} flux. Under the assumption that the {sup 8}B spectrum is undistorted, the measurements from this phase yield a solar {nu}{sub e} flux of {phi}({nu}{sub e})=1.76{sub -0.05}{sup +0.05}(stat.){sub -0.09}{sup +0.09}(syst.)x10{sup 6} cm{sup -2} s{sup -1} and a non-{nu}{sub e} component of {phi}({nu}{sub {mu}}{sub {tau}})=3.41{sub -0.45}{sup +0.45}(stat.){sub -0.45}{sup +0.48}(syst.)x10{sup 6} cm{sup -2} s{sup -1}. The sum of these components provides a total flux in excellent agreement with the predictions of standard solar models. The day-night asymmetry in the {nu}{sub e} flux is found to be A{sub e}=7.0{+-}4.9(stat.){sub -1.2}{sup +1.3}%(syst.), when the asymmetry in the total flux is constrained to be zero.},
doi = {10.1103/PHYSREVC.75.045502},
journal = {Physical Review. C, Nuclear Physics},
number = 4,
volume = 75,
place = {United States},
year = {Sun Apr 15 00:00:00 EDT 2007},
month = {Sun Apr 15 00:00:00 EDT 2007}
}
  • The Sudbury Neutrino Observatory (SNO) used an array of {sup 3}He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active ({nu}{sub x}) {sup 8}B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54{sub -0.31}{sup +0.33}(stat){sub -0.34}{sup +0.36}(syst)x10{sup 6} cm{sup -2} s{sup -1}, in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields {delta}m{sup 2}=7.59{sub -0.21}{sup +0.19}x10{sup -5} eV{sup 2} and {theta}=34.4{sub -1.2}{sup +1.3} degrees. The uncertainty on the mixing anglemore » has been reduced from SNO's previous results.« less
  • This article provides the complete description of resultsfrom the Phase I data set of the Sudbury Neutrino Observatory (SNO). ThePhase I data set is based on a 0.65 kt-year exposure of heavy water tothe solar 8B neutrino flux. Included here are details of the SNO physicsand detector model, evaluations of systematic uncertainties, andestimates of backgrounds. Also discussed are SNO's approach tostatistical extraction of the signals from the three neutrino reactions(charged current, neutral current, and elastic scattering) and theresults of a search for a day-night asymmetry in the ?e flux. Under theassumption that the 8B spectrum is undistorted, the measurements fromthismore » phase yield a solar ?e flux of ?(?e) =1.76+0.05?0.05(stat.)+0.09?0.09 (syst.) x 106 cm?2 s?1, and a non-?ecomponent ?(? mu) = 3.41+0.45?0.45(stat.)+0.48?0.45 (syst.) x 106 cm?2s?1. The sum of these components provides a total flux in excellentagreement with the predictions of Standard Solar Models. The day-nightasymmetry in the ?e flux is found to be Ae = 7.0 +- 4.9 (stat.)+1.3?1.2percent (sys.), when the asymmetry in the total flux is constrained to bezero.« less
  • 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 themore » 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.« less
  • No abstract prepared.
  • A search has been made for sinusoidal periodic variations in the {sup 8}B solar neutrino flux using data collected by the Sudbury Neutrino Observatory over a 4-year time interval. The variation at a period of 1 yr is consistent with modulation of the {sup 8}B neutrino flux by the Earth's orbital eccentricity. No significant sinusoidal periodicities are found with periods between 1 d and 10 years with either an unbinned maximum likelihood analysis or a Lomb-Scargle periodogram analysis. The data are inconsistent with the hypothesis that the results of the recent analysis by Sturrock et al., based on elastic scatteringmore » events in Super-Kamiokande, can be attributed to a 7% sinusoidal modulation of the total {sup 8}B neutrino flux.« less