Revamped Bi-Large neutrino mixing with Gatto-Sartori-Tonin like relation
The Gatto Sartori Tonin (GST) relation which establishes the Cabibbo angle in terms of the quark mass ratio: $θ_{C}=\sqrt{m_d/m_s}$, is instituted as $θ_{13}=\sqrt{m_1/m_3}$ to a Bi-large motivated lepton mixing framework that relies on the unification of mixing parameters: $θ_{13}=θ_{C}$ and $θ_{12}=θ_{23}$. This modification in addition to ruling out the possibility of vanishing $θ_{13}$, advocates for a nonzero lowest neutrino mass and underlines the normal ordering of the neutrino masses. The framework is further enhanced by the inclusion of a charged lepton diagonalizing matrix $U_{lL}$ with $ (θ_{12}^l \sim θ_C, δ=0)$. The model being architected at the Grand unification theory (GUT) scale is further run down upto the $Z$ boson scale to understand the universality of the GST relation and the Cabibbo angle.