A Three-Family $SU(4)_c \otimes SU(2)_w \otimes U(1)$ Type I Vacuum

TL;DR

This paper constructs a specific Type I string theory vacuum with three chiral families, analyzing its gauge symmetry breaking potential to resemble the Standard Model.

Contribution

It presents a novel three-family chiral vacuum in Type I string theory with a detailed superpotential analysis and gauge symmetry breaking prospects.

Findings

Three chiral families in the constructed model.

Potential to break to Standard Model gauge group.

No obvious obstructions to Higgsing the gauge group.

Abstract

We construct a four dimensional chiral N=1 space-time supersymmetric perturbative Type I vacuum corresponding to a compactification on a toroidal Z_2 X Z_2 X Z_3 orbifold with a discrete Wilson line. This model is non-perturbative from the heterotic viewpoint. It has three chiral families in the SU(4)_c X SU(2)_w X U(1) subgroup of the total gauge group. We compute the tree-level superpotential in this model. There appears to be no obvious obstruction to Higgs the gauge group down to SU(3)_c X SU(2)_w X U(1)_Y and obtain the Standard Model gauge group with three chiral families.