A Supersymmetric Theory of Vector-like Leptons

TL;DR

This paper proposes a supersymmetric extension of vector-like leptons that stabilizes the vacuum, preserves gauge coupling unification, and can enhance the Higgs to diphoton decay rate by up to 50% with new particles above 100 GeV.

Contribution

It introduces a supersymmetric model with a full 16+ar{16} of SO(10) to address vacuum instability and gauge unification in vector-like lepton scenarios.

Findings

Higgs to diphoton decay rate can be enhanced by up to 50%.

Vacuum stability is maintained with superpartners at or below the TeV scale.

New particles are kept above 100 GeV to satisfy experimental constraints.

Abstract

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.