Scalar Septuplet Dark Matter and Enhanced $h\rightarrow \gamma\gamma$ Decay Rate

TL;DR

This paper extends the Standard Model with complex septuplet scalars, proposing a dark matter candidate and explaining an enhanced Higgs decay rate to photons, consistent with collider and astrophysical data.

Contribution

It introduces a septuplet scalar extension that accounts for dark matter and enhances the Higgs to gamma gamma decay rate, aligning with recent experimental results.

Findings

Dark matter candidate around 70 GeV compatible with constraints

Higgs to gamma gamma decay rate enhancement factor of 1.5 to 2

Charged septuplet components contribute significantly to decay rate

Abstract

Inspired by recent results on the Higgs search from ATLAS and CMS, we extend the SM with complex septuplet scalars. The lightest neutral component of the septuplets is a natural cold dark Matter candidate and the charged components can contribute to the $h\to \gamma \gamma $ decay rate, providing a significant enhancement factor. The dark matter phenomenology and possible collider signatures of the model are investigated. We find a dark matter candidate with mass around 70 GeV consistent with astrophysical and direct detection constraints. In the meanwhile, the enhancement factor of $h\to \gamma \gamma $ decay rate can be in the range 1.5\sim 2.