Day - Night Effect Predictions for the SNO Detector

Abstract

Detailed predictions for the day-night (D-N) asymmetry in the energy-integrated one year signals in the SNO detector in the case of the MSW ${\nu }_e\to {\nu }_{\mu (\tau )}$ and/or ${\nu }_e\to {\nu }_s$ transition solutions of the solar neutrino problem are presented. The asymmetries in the charged current (CC) and $\nu -e^{-}$ elastic scattering (ES) event rates are calculated for both MSW solutions; in the case of the ${\nu }_e\to {\nu }_s$ transition solution the D-N asymmetry in the neutral current (NC) event rate are derived as well. The asymmetries are calculated for three night samples of events which are produced by the solar neutrinos crossing i) the Earth mantle only (Mantle), ii) the Earth core (Core) and iii) the Earth core and/or the mantle (Night). The effects of the uncertainties, e.g., in the values of the cross-sections of the CC and NC neutrino-induced reactions on deuterium on the corresponding D-N asymmetry predictions are analyzed. It is shown, in particular, that that due to the strong enhancement of the transitions of the solar neutrinos crossing the Earth core, at ${\sin }^{2}2{\theta }_V\le 0.01$ the corresponding one year average D-N asymmetry in the Core sample of CC events in the case of the ${\nu }_e\to {\nu }_{\mu (\tau )}$ solution can be larger by a factor of up to $\sim 8$ than the asymmetry in the Night sample. Iso - (D-N) asymmetry contours in the $\Delta m^2-{\sin }^{2}2{\theta }_V$ plane for the SNO detector are derived in the region $\sin^22θ_V \gsim 10^{-4}$ for the Core and Night samples of the CC, ES and NC events.

27 pages latex text with 10 tables + 25 ps-files; includes 26 figures; results and conclusions unchanged, typos corrected; few improvements made, e.g., references to earlier calculations of the D-N effect for the SNO detector added

Cited by in corpus (18)

• Measurement of Day and Night Neutrino Energy Spectra at SNO and Constraints on Neutrino Mixing Parameters
• The SNO Solar Neutrino Data, Neutrinoless Double Beta-Decay and Neutrino Mass Spectrum
• Imprint of SNO neutral current data on the solar neutrino problem
• Update of the solar neutrino oscillation analysis with the 766 Ty KamLAND spectrum
• Constraints on neutrino oscillation parameters from the SNO salt phase data
• Toward precision measurements in solar neutrinos
• Global Analysis with SNO: Toward the Solution of the Solar Neutrino Problem
• Addendum: The SNO Solar Neutrino Data, Neutrinoless Double Beta-Decay and Neutrino Mass Spectrum
• Robust signatures of solar neutrino oscillation solutions
• Zenith angle distributions at Super-Kamiokande and SNO and the solution of the solar neutrino problem
• Piecing the Solar Neutrino Puzzle Together at SNO
• Four-Neutrino Oscillations at SNO
• On the Day-Night Effect and CC to NC Event Rate Ratio Predictions for the SNO Detector
• On the Measurement of Solar Neutrino Oscillation Parameters with KamLAND
• Neutrino mass matrix in Anti-GUT with see-saw mechanism
• Earth Regeneration of Solar Neutrinos at SNO and Super-Kamiokande
• The sign of the day-night asymmetry for solar neutrinos
• Four--Neutrino Oscillations at SNO