Stabilizing Moduli with a Positive Cosmological Constant in Heterotic M-Theory

TL;DR

This paper demonstrates that strongly coupled heterotic M-theory with anti-five-branes can produce metastable vacua with broken supersymmetry and a small positive cosmological constant, compatible with the MSSM spectrum.

Contribution

It shows the existence of metastable vacua with positive cosmological constant in heterotic M-theory including anti-five-branes, extending previous models with only five-branes.

Findings

Metastable vacua with positive cosmological constant are achievable.

Observable sector matches MSSM spectrum.

Stability conditions relate to Kahler moduli and vector bundle slope stability.

Abstract

It is shown that strongly coupled heterotic M-theory with anti-five-branes in the S^1/Z_2 bulk space can have meta-stable vacua which break N=1 supersymmetry and have a small, positive cosmological constant. This is demonstrated for the "minimal" heterotic standard model. This vacuum has the exact MSSM matter spectrum in the observable sector, a trivial hidden sector vector bundle and both five-branes and anti-five-branes in the bulk space. The Kahler moduli for which the cosmological constant has phenomenologically acceptable values are shown to also render the observable sector vector bundle slope-stable. A corollary of this result is that strongly coupled M-theory vacua with only five-branes in the S^1/Z_2 interval may have stabilized moduli, but at a supersymmetry preserving minimum with a large, negative cosmological constant.