Supersymmetric Hidden Sectors for Heterotic Standard Models

Within the context of the weakly coupled E8 x E8 heterotic string, we study the hidden sector of heterotic standard model compactifications to four-dimensions. Specifically, we present a class of hidden sector vector bundles - composed of the direct sum of line bundles only - that, together with an effective bulk five-brane, renders the heterotic standard model entirely N=1 supersymmetric. Two explicit hidden sectors are constructed and analyzed in this context; one with the gauge group E7 x U(1) arising from a single line bundle and a second with an SO(12) x U(1) x U(1) gauge group constructed from the direct sum of two line bundles. Each hidden sector bundle is shown to satisfy all requisite physical constraints within a finite region of the Kahler cone. We also clarify that the first Chern class of the line bundles need not be even in our context, as has often been imposed in the model building literature.