Three-Family Models from a Heterotic Orbifold on the E_6 Root Lattice

TL;DR

This paper classifies N=1 orbifolds on the E_6 lattice, constructs heterotic string models with three families, and explores their flavor mixing and gauge structures, revealing new GUT-like models with complex sectors.

Contribution

It provides a classification of orbifolds on the E_6 lattice and constructs explicit three-family GUT models with novel features like flavor mixing and hidden sectors.

Findings

Some twisted sectors have three fixed tori producing degenerate massless states.

Identified three-point functions with flavor mixing.

Constructed GUT-like models with hidden sectors and messenger states.

Abstract

We classify N=1 orbifolds on the E_6 root lattice and investigate explicit model constructions on the Z_3xZ_3 orbifold in heterotic string theory. Interestingly some of the twisted sectors from the Z_3xZ_3 orbifold on the E_6 root lattice have just three fixed tori respectively, and generate three degenerate massless states. We also found three point functions with flavor mixing terms. We assume only non-standard gauge embeddings and find that they lead to three-family SU(5) and SO(10) GUT-like models. These models also include strongly coupled sectors in the low energy and messenger states charged with both hidden and visible sectors.