Vacuum Stability Constraints on the Enhancement of the Higgs to Diphoton Rate in the MSSM

TL;DR

This paper investigates how vacuum stability constraints limit the possible enhancement of the Higgs to diphoton decay rate in the MSSM, showing that large enhancements are severely restricted by vacuum meta-stability conditions.

Contribution

It applies vacuum meta-stability conditions to constrain the Higgs to diphoton rate enhancement in the MSSM, providing quantitative bounds based on stau mass and mixing.

Findings

Vacuum meta-stability severely constrains Higgs to diphoton rate enhancement.

For a 100 GeV stau, the maximum enhancement is approximately 25%.

Large stau mixing can lead to vacuum instability, limiting possible signal enhancements.

Abstract

The ATLAS and CMS collaborations discovered a new boson particle. If the new boson is the Higgs boson, the diphoton signal strength is 1.5 - 1.8 times larger than the Standard Model (SM) prediction, while the WW and ZZ signal strengths are in agreement with the SM one. In the Minimal Supersymmetric Standard Model (MSSM), overall consistency can be achieved by a light stau and the large left-right mixing of staus. However, a light stau and large left-right mixing of staus may suffer from vacuum instability. We first apply the vacuum meta-stability condition to the Higgs to diphoton decay rate in the MSSM. We show that the vacuum meta-stablity severely constrains the enhancement to the Higgs to diphoton rate. For example, when the lighter stau mass is 100 GeV, the upper bound on the enhancement to the Higgs to diphoton rate becomes 25%.