Predictive Pati-Salam theory of fermion masses and mixing

Abstract

We propose a Pati-Salam extension of the standard model incorporating a flavor symmetry based on the ∆ (27) group. The theory realizes a realistic Froggatt-Nielsen picture of quark mixing and a predictive pattern of neutrino oscillations. We find that, for normal neutrino mass ordering, the atmospheric angle must lie in the higher octant, CP must be violated in oscillations, and there is a lower bound for the 0νββ decay rate. For the case of inverted mass ordering, we find that the lower atmospheric octant is preferred, and that CP can be conserved in oscillations. Neutrino masses arise from a low-scale seesaw mechanism, whose messengers can be produced by a Z portal at the LHC.

Neutrino predictions from a left-right symmetric flavored extension of the standard model

“…As shown in detail in Ref. [7], the following VEV alignments for the ∆(27) scalar triplets are consistent with the scalar potential minimization equations for a large region of parameter space:…”

“…This group was proposed for the first time in Ref. [28] and it has been employed in order to construct the Pati-Salam electroweak extension proposed in [7]. This group has also been used in multiscalar singlet models [29], multi-Higgs doublet models [30,31], Higgs triplet models [32] SO(10) models [33][34][35], warped extra dimensional models [36], and models based on the SU (3) C ⊗SU (3) L ⊗U (1) X gauge symmetry [37][38][39].…”

“…Combining these features is a desirable step forward. Indeed, a predictive Pati-Salam theory of fermion masses and mixing combining both approaches has been suggested recently [7].…”

“…As a result, they can be integrated out, yielding effective non-renormalizable operators as in Eq. (7).…”

Determination of the θ23 octant in long baseline neutrino experiments within and beyond the standard model

“…In that case, the ν μ and ν τ flavors would have an equal weight in the ν 3 mass state. In some models the octant of θ 23 is directly related to the neutrino mass hierarchy, e.g., in the model considered in [19], the mass hierarchy for the higher octant is normal and for the lower octant the mass hierarchy is inverted.…”