Consequences of minimal seesaw with complex $\mu\tau$ antisymmetry of neutrinos

Understand

We propose a complex extension of $\mu\tau$ permutation antisymmetry in the neutrino Majorana matrix $M_\nu$.

• The latter can be realized for the Lagrangian by appropriate CP transformations on the neutrino fields.
• The resultant form of $M_\nu$ is shown to be simply related to that with a complex (CP) extension of $\mu\tau$ permutation symmetry, with identical phenomenological consequences, though their group theoretic origins are quite different.
• We investigate those consequences in detail for the minimal seesaw induced by two strongly hierarchical right-chiral neutrinos $N_1$ and $N_2$ with the result that the Dirac phase is maximal while the two Majorana phases are either 0 or $\pi$.