Investigation of low Higgs models in Weakly Coupled Free Fermionic Heterotic String Theory.

Superstring phenomenology explores classes of vacua which can reproduce the Standard Model at low energy. We consider Weakly Coupled Free Fermionic Heterotic String Theory (WCFFHST) which produces four dimensional Standard-like Models and allows for their SO(10) embedding. In the models herein, we explore the removal of extra Higgs representations via free fermion boundary conditions directly at the string level, rather than in the low energy effective field theory. We focus on the flat direction analysis of four models with reduced number of Higgs, after flat direction analysis of a three generation reduced Higgs model revealed no stringent F- and D-flat solutions to all order in the superpotential. Flat direction analysis of the four models presented herein shows the lack of D- and F-flat solutions to all order is not a general property of low Higgs models, as stringent flat directions appear to all order for three of our four models.