It has recently been shown that the phenomenologically successful pattern of cobimaximal neutrino mixing ($theta_{13} eq 0$, $theta_{23} = pi/4$, and $delta_{CP} = pm pi/2$) may be achieved in the context of the non-Abelian discrete symmetry $A_4$, if the neutrino mass matrix is diagonalized by an orthogonal matrix ${cal O}$. We study how this pattern would deviate if ${cal O}$ is replaced by an unitary matrix.
Download