Interpolations among NAHE-based supersymmetric and nonsupersymmetric string vacua

The quasi-realistic free fermionic heterotic-string models provide some of the most detailed examples to explore the phenomenology of string unification. While providing a powerful tool to generate models and their spectra, understanding the realisation of the free fermion models in a bosonic formalism will provide important insight into their basic properties away from the free fermion point. In this Letter we elucidate bosonic equivalent of the basic symmetry breaking pattern in the free fermion models from E8×E8 to SO(16)×SO(16) and exhibit the connection of the free fermion models with corresponding nonsupersymmetric vacua by interpolations.