The Minimal Scalar-Stealth Top Interpretation of the Diphoton Excess

TL;DR

This paper proposes a minimal model with a 750 GeV scalar and stealth vector quarks to explain the diphoton excess observed at the LHC, highlighting how the model enhances the diphoton rate while evading current constraints.

Contribution

It introduces a simplified stealth quark model that accounts for the diphoton excess without conflicting with existing LHC search limits.

Findings

Stealth quarks around 400-500 GeV can explain the diphoton excess.

The model enhances diphoton rate significantly while avoiding di-jet constraints.

Potential other signatures of the stealth model are discussed.

Abstract

A resonance near 750 GeV has been observed at both the ATLAS and CMS experiments in its diphoton decay channel. We propose a possible interpretation based on a simplified model: a 750 GeV singlet scalar resonance, and a minimal stealth vector quark are introduced. At the LHC, the scalar is produced through gluon fusion, and subsequently decays to diphoton final state. The light stealth quarks could enhance the diphoton rate significantly, while still keeping other channels below the current LHC search limits. We find that the stealth quarks around 400 ~ 500 GeV with its coupling to scalar around 0.5 ~ 1.5 could explain the diphoton excess, and avoid current di-jet constraints. We also comment on other potential signatures of this stealth model.