Maximal nu(e) -> nu(s) solution to the solar neutrino problem: just-so, MSW or energy independent?

Abstract

We examine the maximal νe → νs solution to the solar neutrino problem. This solution can be motivated by the exact parity model and other theories. The νe survival probability exhibits one of three qualitatively different behaviours depending on the value of Δm2, viz. approximately energy independent, just-so or MSW. By the last of these we mean an enhanced night-time event rate due to regeneration in the Earth. We study all of these possibilities in the context of the recent SuperKamiokande data. © 1999 Elsevier Science B.V. All rights reserved.