Realistic Superstring Models
Abstract
I discuss the construction of realistic superstring standardlike models in the four dimensional free fermionic formulation. I discuss the massless spectrum of the superstring standardlike models and the texture of fermion mass matrices. These models suggest an explanation for the top quark mass hierarchy. At the cubic level of the superpotential only the top quark get a mass term. The lighter quarks and leptons obtain their mass terms from nonrenormalizable terms that are suppressed relative to the cubic order term. A numerical estimate yielded $m_t\sim175180~GeV$. The suppression of the lightest generation masses results from the horizontal symmetries in the superstring models. The problems of neutrino masses, gauge coupling unification and hierarchical SUSY breaking are discussed. I argue that the realistic features of these models are due to the underlying $Z_2\times Z_2$ orbifold, with standard embedding, at the free fermionic point in toroidal compactification space.
 Publication:

arXiv eprints
 Pub Date:
 May 1994
 arXiv:
 arXiv:hepph/9405357
 Bibcode:
 1994hep.ph....5357F
 Keywords:

 High Energy Physics  Phenomenology;
 High Energy Physics  Theory
 EPrint:
 IASSNSHEP94/31, 20 pages, phyzzx