A Heterotic Standard Model with B-L Symmetry and a Stable Proton

Understand

We consider heterotic Calabi-Yau compactifications with S(U(4)xU(1)) background gauge fields.

• These models lead to gauge groups with an additional U(1) factor which, under certain conditions, can combine with hypercharge to a B-L symmetry.
• The associated gauge boson is automatically super-massive and, hence, does not constitute a phenomenological problem.
• We illustrate this class of compactifications with a model based on the monad construction, which leads to a supersymmetric standard model with three families of quarks and leptons, one pair of Higgs doublets, three right-handed neutrinos and no exotics charged under the standard model group.