Supersymmetric Three Family SU(5) Grand Unified Models from Type IIA Orientifolds with Intersecting D6-Branes

TL;DR

This paper constructs supersymmetric three-family SU(5) GUT models using type IIA orientifolds with intersecting D6-branes, analyzing their spectra, geometric M-theory lifts, and preliminary phenomenological implications.

Contribution

It systematically constructs and analyzes supersymmetric three-family SU(5) GUT models from type IIA orientifolds with intersecting D6-branes, including their geometric M-theory lifts.

Findings

No supersymmetric three-family models with three 10-plets unless 15-plets are present.

Models correspond to singular G2 manifolds with localized gauge symmetries and chiral fermions.

Preliminary phenomenological features are explored.

Abstract

We construct some N=1 supersymmetric three-family SU(5) Grand Unified Models from type IIA orientifolds on $\IT^6/(\IZ_2\times \IZ_2)$ with D6-branes intersecting at general angles. These constructions are supersymmetric only for special choices of untwisted moduli. We show that within the above class of constructions there are no supersymmetric three-family models with 3 copies of {\bf 10}-plets unless there are simultaneously some {\bf 15}-plets. We systematically analyze the construction of such models and their spectra. The M-theory lifts of these brane constructions become purely geometrical backgrounds: they are singular $G_2$ manifolds where the Grand Unified gauge symmetries and three families of chiral fermions are localized at codimension 4 and codimension 7 singularities respectively. We also study somepreliminary phenomenological features of the models.