Quasi-Supersymmetric $G^3$ Unification from Intersecting D6-Branes on Type IIA Orientifolds

TL;DR

This paper constructs three quasi-supersymmetric G3 grand unified models with S3 symmetry from intersecting D6-branes on Type IIA orientifolds, embedding Standard Model particles without extraneous states and achieving gauge unification.

Contribution

It introduces new intersecting D6-brane models with G3 symmetry that realize the Standard Model spectrum and gauge unification without extra massless states.

Findings

Three models with G3 symmetry and gauge unification.

Standard Model fermions and Higgs embedded in bifundamentals.

Gauge symmetry breaking to SM achieved via light open string states.

Abstract

We construct three quasi-supersymmetric $G^3$ GUT models with $S_3$ symmetry and gauge coupling unification from intersecting D6-branes on Type IIA orientifolds. The Standard Model fermions and Higgs doublets can be embedded into the bifundamental representations in these models, and there is no any other unnecessary massless representation. Especially in Model I with gauge group $U(4)^3$, we just have three-family SM fermions and three pairs of Higgs particles. The $G^3$ gauge symmetry in these models can be broken down to the Standard Model gauge symmetry by introducing light open string states. And 1 TeV scale supersymmetry breaking soft masses imply the reasonable intermediate string scale.