Higgs diphoton rate and mass enhancement with vector-like leptons and the scale of supersymmetry

TL;DR

This paper investigates how vector-like leptons and their superpartners can enhance the Higgs diphoton decay rate and increase the Higgs mass, potentially lowering the supersymmetry scale and offering testable collider signatures.

Contribution

It provides a detailed analysis of the impact of vector-like leptonic supermultiplets on Higgs properties and explores the correlation between diphoton rate enhancement and Higgs mass correction.

Findings

Higgs diphoton rate can be enhanced by a factor of 1.4-1.8.

Higgs mass can receive a positive correction of 4-10 GeV.

Extra contributions allow for a lower supersymmetry scale.

Abstract

Analysis of contributions from vector-like leptonic supermultiplets to the Higgs diphoton decay rate and to the Higgs boson mass is given. Corrections arising from the exchange of the new leptons and their super-partners, as well as their mirrors are computed analytically and numerically. We also study the correlation between the enhanced Higgs diphoton rate and the Higgs mass corrections. Specifically, we find two branches in the numerical analysis: on the lower branch the diphoton rate enhancement is flat while on the upper branch it has a strong correlation with the Higgs mass enhancement. It is seen that a factor of 1.4-1.8 enhancement of the Higgs diphoton rate on the upper branch can be achieved, and a 4-10 GeV positive correction to the Higgs mass can also be obtained simultaneously. The effect of this extra contribution to the Higgs mass is to release the constraint on weak scale supersymmetry, allowing its scale to be lower than in the theory without extra contributions. The vector-like supermultiplets also have collider implications which can be tested at the LHC and at the ILC.