Plamen I. Krastev

Neutrino oscillation scenarios predict correlations, and zones of avoidance, among measurable quantities such as spectral energy distortions, total fluxes, time dependences, and flavor content. The comparison of observed and predicted correlations will enhance the diagnostic power of solar neutrino experiments. A general test of all presently-allowed (two neutrino) oscillation solutions is that future measurements must yield values outside the predicted zones of avoidance. To illustrate the discriminatory power of the simultaneous analysis of multiple observables, we map currently allowed regions of neutrino masses and mixing angles onto planes of quantities measurable with the Sudbury Neutrino Observatory (SNO). We calculate the correlations that are predicted by vacuum and MSW (active and sterile) neutrino oscillation solutions that are globally consistent with all available neutrino data. We derive approximate analytic expressions for the dependence of individual observables and specific correlations upon neutrino oscillations parameters. We also discuss the prospects for identifying the correct oscillation solution using multiple SNO observables.

We calculate the range of predicted values for 10 quantities that will be measured by the Sudbury Neutrino Observatory (SNO). We use neutrino oscillation solutions (vacuum and MSW; active and sterile neutrinos) that are globally consistent with all available neutrino data and estimate realistic theoretical and experimental uncertainties. The neutral current to charged current double ratio is predicted to be more than 9 sigma from the no-oscillation solution for all of the currently favored neutrino oscillation solutions. The best-fit oscillation solutions predict a CC day-night rate difference between -0.1% and +12.5% and a NC day-night difference < 0.01%. We present also the predicted range for the first and the second moments of the charged current electron recoil energy spectrum, the charged current, the neutral current, and the neutrino-electron scattering rates, the seasonal dependence of the charged current rate, and the double ratio of neutrino-electron scattering rate to charged current rate.

The ratio of the measured to the predicted standard model CC event rates in SNO will be 0.47 if no oscillations occur. The best-fit active oscillation predictions for the CC ratio are: 0.35-39 (MSW) and 0.38-42 (vacuum) (all for a 5 MeV energy threshold), typically about 20% less than the no-oscillation expectation. We calculate the predicted ratios for six active and sterile neutrino oscillation solutions allowed at 99% CL and determine the dependence of the ratios on energy threshold. If the high-energy anomaly observed by SuperKamiokande is due to an enhanced hep flux, MSW active solutions predict that out of a total of 5000 CC events above 5 MeV in SNO between 49 and 54 events will be observed above 13 MeV whereas only 19 events are expected for no-oscillations and a nominal standard hep flux.

If the low energy cross section for 3He + p goes to 4He + e + nu_e, the `hep' reaction, is > 20 times larger than the best (but uncertain) theoretical estimates, then this reaction could significantly influence the electron energy spectrum produced by solar neutrino interactions and measured in the SuperKamiokande, SNO, and ICARUS experiments. We compare predicted energy spectra for different assumed hep fluxes and different neutrino oscillation scenarios with the observed SuperKamiokande spectrum. The spectra with enhanced hep contributions provide better fits to the SuperKamiokande data.