Planck scale unification in a supersymmetric Standard Model

Abstract

We show how gauge coupling unification near the Planck scale Mp∼1019 GeV can be achieved in the framework of supersymmetry, facilitating a full unification of all forces with gravity. Below the conventional GUT scale MGUT∼1016 GeV physics is described by a Supersymmetric Standard Model whose particle content is that of three complete 27 representations of the gauge group E6. Above the conventional GUT scale the gauge group corresponds to a left–right symmetric Supersymmetric Pati–Salam model, which may be regarded as a “surrogate SUSY GUT” with all the nice features of SO(10) but without proton decay or doublet–triplet splitting problems. At the TeV scale the extra exotic states may be discovered at the LHC, providing an observable footprint of an underlying E6 gauge group broken at the Planck scale. Assuming an additional low energy U(1)X gauge group, identified as a non-trivial combination of diagonal E6 generators, the μ problem of the MSSM can be resolved.