Aspects of non-renormalizable terms in a superstring derived standard-like model

Abstract

I investigate the role of non-renormalizable terms, up to order N = 8, in a superstring derived standard-like model. I argue that non-renormalizable terms restrict the gauge symmetry, at the Planck scale, to be SU(3)×SU(2)×U(1) B ×U(1) T 3 R rather than SU(3)×SU(2)×U(1) Y . I show that breaking the gauge symmetry directly to the Standard Model leads to breaking of supersymmetry at the Planck scale, or to dimension four, baryon and lepton violating, operators. I show that if the gauge symmetry is broken directly to the Standard Model the cubic-level solution to the F and D flatness constraints is violated by higher-order terms, while if U(1) Z' remains unbroken at the Planck scale, the cubic-level solution is valid to all orders of non-renormalizable terms. I discuss the Higgs and fermion mass spectrum. I demonstrate that realistic, hierarchical, fermion mass spectrum can be generated in this model.