Simplest Neutrino Mixing from S4 Symmetry

Understand

In 2004, two of us proposed a texture, the "Simplest" neutrino mass matrix, which predicted sin(theta13)=sqrt((2 Solar-Delta m^2)/(3 Atm-Delta m^2)) and delta_CP=90 degrees.

• Using today's measured values for neutrino mass-squared differences, this prediction gives sin^2(theta13)~0.086+0.003-0.006, compared with a measured value, found by averaging the results of the Daya Bay and RENO experiments, of sin^2(theta13)=0.093+0.010-0.010.
• Here we present a specific model based on S4 symmetry leading to this successful texture in the context of the type-1 see-saw mechanism, assuming Majorana neutrinos.
• In this case, slightly different predictions are obtained relating theta13 to the light neutrino masses, which are in accord with current experimental limits and testable at future experiments.