Parametrization of PMNS matrix based on dodeca-symmetry
  The dodeca symmetry is designed to obtain the Cabibbo angle $\theta_C^{\rm CKM}$ approximately $15^{\rm o}$ and the (11) element of $\Vp$ as $\cos 30^{\rm o}$, leading to $\theta_1^{\rm PMNS}+\theta_C^{\rm CKM}\simeq 45^{\rm o}$. This leading order dodeca symmetric $\Vp$ is corrected by small parameters, especially as an expansion in terms of a small parameter $\beta$. Neglecting two Majorana phases, the expression of $\Vp$ contains four parameters: a small $\beta$, and three $\Od(1)$ parameters $A,B,$ and $\delta$. From the neutrino oscillation data, we present two parametrizations and estimate their $\beta$'s. 
Jihn E. Kim and Min-Seok Seo
hep-ph