SUSY SU(5) with singlet plus adjoint matter and A4 family symmetry

TL;DR

This paper develops a SUSY SU(5) GUT model incorporating a singlet and adjoint matter, extended with A4 symmetry, to naturally produce hierarchical neutrino masses and realistic quark-lepton mixing patterns.

Contribution

It introduces a novel SUSY SU(5) model with combined type I and III seesaw mechanisms, A4 symmetry, and a gauged Abelian group, achieving realistic fermion masses and mixings.

Findings

Hierarchical neutrino masses from combined seesaw mechanisms.

Tri-bimaximal mixing arises indirectly via A4 symmetry.

Reproduces realistic quark and lepton mass relations, including Georgi-Jarlskog.

Abstract

We propose a supersymmetric (SUSY) SU(5) Grand Unified Theory (GUT) including a single right-handed neutrino singlet and an adjoint matter representation below the GUT scale and extend this model to include an A4 family symmetry and a gauged anomaly-free Abelian group. In our approach hierarchical neutrino masses result from a combined type I and type III seesaw mechanism, and the A4 symmetry leads to tri-bimaximal mixing which arises indirectly. The mixing between the single right-handed neutrino and the matter in the adjoint is forbidden by excluding an adjoint Higgs, leading to a diagonal heavy Majorana sector as required by constrained sequential dominance. The model also reproduces a realistic description of quark and charged lepton masses and quark mixings, including the Georgi-Jarlskog relations and the leptonic mixing sum rules s=r*cos(delta) and a=-r^2/4 with r=theta_C/3.