Abstract
The possible existence of maximal or near-maximal lepton mixing constitutes an intriguing challenge for fundamental theories of flavor. We study the phenomenological consequences of maximal and near-maximal mixing of the electron neutrino with other and/or muon) neutrinos. We describe the deviations from maximal mixing in terms of a parameter and quantify the present experimental status for We show that both probabilities and observables depend on quadratically when effects are due to vacuum oscillations and they depend on linearly if matter effects dominate. The most important information on mixing comes from solar neutrino experiments. We find that the global analysis of solar neutrino data allows maximal mixing with confidence level better than 99% for In the mass ranges and the full interval is allowed within (99.995% CL) We suggest ways to measure in future experiments. The observable that is most sensitive to is the rate [NC]/[CC] in combination with the day-night asymmetry in the SNO detector. With theoretical and statistical uncertainties, the expected accuracy after 5 years is We also discuss the effects of maximal and near-maximal mixing in atmospheric neutrinos, supernova neutrinos, and neutrinoless double beta decay.
- Received 31 July 2000
DOI:https://doi.org/10.1103/PhysRevD.63.013007
©2000 American Physical Society