Heterotic road to the MSSM with R parity

In a previous paper, referred to as a Mini-Landscape search, we explored a fertile patch of the heterotic landscape based on a Z(6)-II orbifold with SO(10) and E-6 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.