Raising the Higgs mass with Yukawa couplings for isotriplets in vector-like extensions of minimal supersymmetry

TL;DR

This paper explores how adding vector-like isotriplet and isodoublet matter with large Yukawa couplings can increase the Higgs boson mass in supersymmetric models while maintaining perturbative unification and acceptable electroweak precision tests.

Contribution

It introduces a model with large Yukawa couplings between isotriplet and isodoublet supermultiplets that raises the Higgs mass and remains consistent with unification and electroweak constraints.

Findings

Yukawa couplings can significantly increase the Higgs mass.

Electroweak precision observables remain within acceptable bounds.

New fermions could be as light as current experimental limits.

Abstract

Extra vector-like matter with both electroweak-singlet masses and large Yukawa couplings can significantly raise the lightest Higgs boson mass in supersymmetry through radiative corrections. I consider models of this type that involve a large Yukawa coupling between weak isotriplet and isodoublet chiral supermultiplets. The particle content can be completed to provide perturbative gauge coupling unification, in several different ways. The impact on precision electroweak observables is shown to be acceptably small, even if the new particles are as light as the current experimental bounds of order 100 GeV. I study the corrections to the lightest Higgs boson mass, and discuss the general features of the collider signatures for the new fermions in these models.