Large diphoton Higgs rates from supersymmetric triplets

TL;DR

Introducing a supersymmetric triplet extension to the Higgs sector can increase the Higgs mass and diphoton decay rate, addressing tensions in the MSSM with recent LHC results.

Contribution

The paper demonstrates that adding a supersymmetric triplet to the Higgs sector alleviates fine-tuning and enhances diphoton decay rates, aligning theory with experimental data.

Findings

Triplet extension raises Higgs mass without heavy squarks

Charged component increases diphoton decay rate by up to 50%

Scenario remains compatible with electroweak precision tests

Abstract

Recent results on Higgs searches at the LHC point towards the existence of a Higgs boson with mass of about 126 GeV whose diphoton decay rate tends to be larger than in the Standard Model. These results are in tension with natural MSSM scenarios: such a Higgs mass requires heavy (third-generation) squarks which reintroduce some amount of fine-tuning and in general the Higgs diphoton decay rate tends to follow the Standard Model result. In this paper we prove that these problems can be alleviated by introducing an extra supersymmetric triplet coupled to the Higgs in the superpotential. This superfield generates a sizeable tree-level correction to the Higgs mass so that the third generation is no longer required to be heavy, and its charged component enhances the diphoton Higgs decay rates by as much as 50% with respect to the Standard Model values. We also show that such a scenario is compatible with present electroweak precision observables.