SpontaneousCPviolation inA4×SU(5)with constrained sequential dominance 2

Abstract

We revisit a two right-handed neutrino model with two texture zeros, namely an indirect model based on ${A}_{4}$ with the recently proposed new type of constrained sequential dominance (CSD2), involving vacuum alignments along the $(0,1,\ensuremath{-}1{)}^{T}$ and $(1,0,2{)}^{T}$ directions in flavor space, which are proportional to the neutrino Dirac mass matrix columns. In this paper we construct a renormalizable and unified indirect ${A}_{4}\ifmmode\times\else\texttimes\fi{}SU(5)$ model along these lines and show that, with spontaneous $CP$ violation and a suitable vacuum alignment of the phases, the charged lepton corrections lead to a reactor angle in good agreement with results from Daya Bay and RENO. The model predicts a right-angled unitarity triangle in the quark sector and a Dirac $CP$ violating oscillation phase in the lepton sector of $\ensuremath{\delta}\ensuremath{\approx}130\ifmmode^\circ\else\textdegree\fi{}$, while providing a good fit to all quark and lepton masses and mixing angles.