Expansion of $U_{PMNS}$ and Neutrino mass matrix $M_{\nu}$ in terms of   $sin\theta_{13}$ for Inverted Hierarchical case
  The recent observational data supports the deviation from Tri-bimaximal (TBM) mixings. Different neutrino mass models suggest the interdependency among the observational parameters involving the mixing angles. On phenomenological ground we try to construct the PMNS matrix $U_{PMNS}$ with certain analytic structure satisfying the unitary condition, in terms of a single observational parameter $sin\theta_{13}$. We hypothesise the three neutrino masses $m_{i}$ as functions of $sin\theta_{13}$ and then construct the neutrino mass matrix $M_{\nu}$. We assume the convergence of the model to TBM mixing when $\theta_{13}$ is taken zero. This mass matrix so far obtained can be employed for various applications including the estimation of matter-antimatter asymmetry of the Universe. 
Subhankar Roy and N. Nimai Singh
hep-ph