Speaker
Description
Curent neutrino oscillation data tell us that what is behind the observed neutrino mixing pattern should at least be an approximate mu-tau flavor symmetry. This suggests that there may exist an exact mu-tau flavor symmetry in the neutrino sector at a superhigh energy scale (e.g., the scale that the seesaw mechanism works), and it will be spontaneously broken due to the renormalization-group evolution down to the electroweak scale. We shall report our latest studies in this respect, and establish the connection between mu-tau symmetry breaking and the octant of theta(23) and the quadrant of delta in the standard parametrization of the PMNS matrix. We find that current experimental data can be interpreted in this way. Some model-building issues will also be addressed.
