A Supersymmetric Theory of Vector-like Leptons

Understand

We study a supersymmetric extension of the vector-like lepton scenario, such that the vacuum instability induced by large lepton Yukawa couplings is lifted by the presence of superpartners at or below the TeV scale.

• In order to preserve the unification of gauge couplings, we introduce a full 16+\bar{16} of SO(10), and determine the maximal possible values for the Yukawa couplings consistent with perturbativity at the GUT scale.
• We find that the Higgs to diphoton decay rate can be enhanced by up to 50% while maintaining vacuum stability and keeping the new particle masses above 100 GeV, while larger enhancements are possible if the masses of the new particles are lowered further.