Normal and Special Models of Neutrino Masses and Mixings
Abstract
Description
One can make a distinction between "normal" and "special" models. For normal models $θ_{23}$ is not too close to maximal and $θ_{13}$ is not too small, typically a small power of the self-suggesting order parameter $\sqrt{r}$, with $r=Δm_{sol}^2/Δm_{atm}^2 \sim 1/35$. Special models are those where some symmetry or dynamical feature assures in a natural way the near vanishing of $θ_{13}$ and/or of $θ_{23}- π/4$. Normal models are conceptually more economical and much simpler to construct. Here we focus on special models, in particular a recent one based on A4 discrete symmetry and extra dimensions that leads in a natural way to a Harrison-Perkins-Scott mixing matrix.
To be published in the Proceedings of Rencontres de Physique de la Vallée d'Aoste, La Thuile, Italy
To be published in the Proceedings of Rencontres de Physique de la Vallée d'Aoste, La Thuile, Italy