We explore a "fertile patch" of the heterotic landscape based on a Z6 -II orbifold with SO(10) and E6 local GUT structures. We search for models allowing for the exact MSSM spectrum. Our result is that of order 100 out of a total 3 × 104 inequivalent models satisfy this requirement. © 2006 Elsevier B.V. All rights reserved.

We study possible correlations between properties of the observable and hidden sectors in heterotic string theory. Specifically, we analyze the case of the Z6-II orbifold compactification which produces a significant number of models with the spectrum of the supersymmetric standard model. We find that requiring realistic features does affect the hidden sector such that hidden sector gauge group factors SU(4) and SO(8) are favored. In the context of gaugino condensation, this implies low energy supersymmetry breaking.

In a previous paper, referred to as a "Mini-Landscape" search, we explored a "fertile patch" of the heterotic landscape based on a Z6-II orbifold with SO(10) and E6 local grand unified theory structures. In the present paper we extend this analysis. We find many models with the minimal supersymmetric standard model spectra and an exact R parity. In all of these models, the vectorlike exotics decouple along D-flat directions. We present two benchmark models which satisfy many of the constraints of a realistic supersymmetric model, including nontrivial Yukawa matrices for three families of quarks and leptons and Majorana masses for right-handed neutrinos with nontrivial seesaw masses for the three light neutrinos. In an appendix we comment on the important issue of string selection rules and, in particular, the so-called "gamma-rule". © 2008 The American Physical Society.