On the Day-Night Effect and CC to NC Event Rate Ratio Predictions for the SNO Detector

Abstract

Detailed predictions for the D-N asymmetry for the Super-Kamiokande and SNO experiments, as well as for the ratio of the CC and NC event rates measured by SNO, in the cases of the LMA MSW and of the LOW solutions of the solar neutrino problem, are derived. The possibilities to further constrain the regions of the LMA MSW and LOW solutions of the solar neutrino problem by using the forthcoming SNO data on the D-N asymmetry and on the CC to NC event rate ratio are also discussed.

Comments: 16 pages, LATEX; 10 pages of text, 12 eps-files; the text includes 6 figures; results and conclusions unchanged, the iso-(D-N) asymmetry and CC to NC event rate ratio contour plots (Figs. 1 - 6) are given in the \Delta m^2 - \tan^2\theta plane, a comment about the uncertainty in the theoretical predictions for CC to NC event rate ratio in the absence of solar neutrino oscillations and one sub-figure added; contains 3 more figures with respect to the version to be published in Physics Letters B