Radiative gauge symmetry breaking in an N=2 superconformal string compactification

We study the intermediate scale gauge symmetry breaking in a four-generation heterotic string model based on Gepner's N=2 superconformal string compactifications. The visible sector gauge group, at the Planck scale, is SU(3)C x SU(2)L x SU(2)R x U(1)' x U(1)'. Putting in by hand soft supersymmetry breaking terms, we evolve the masses and couplings down from the Planck scale using the renormalization group equations and minimize the effective potential. We find that the U(1)' gauge group is broken at a scale of approximately 1015GeV. (orig.)