Investigation of Quasi--Realistic Heterotic String Models with Reduced Higgs Spectrum

Understand

Quasi--realistic heterotic-string models in the free fermionic formulation typically contain an anomalous U(1), which gives rise to a Fayet-Iliopolous term that breaks supersymmetry at the one--loop level in string perturbation theory.

• Supersymmetry is restored by imposing F- and D-flatness on the vacuum.
• In Phys.
• Rev.