Interpreting the 750 GeV diphoton excess in the Minimal Dilaton Model

TL;DR

This paper interprets the 750 GeV diphoton excess within the Minimal Dilaton Model, showing it can match observed rates while satisfying constraints, and discusses implications for LHC signatures and vacuum stability.

Contribution

It provides an analytic framework linking the diphoton excess to dilaton-Higgs mixing and fermion parameters, and demonstrates the model's viability through parameter scans.

Findings

The model can reproduce the observed diphoton rate.

The diphoton signal depends mainly on the mixing angle and fermion number.

Predictions are consistent with current experimental constraints.

Abstract

We try to interpret the 750 GeV diphoton excess in the Minimal Dilaton Model, which extends the SM by adding one linearized dilaton field and vector-like fermions. We first show by analytic formulae in this framework that the production rates of the $\gamma \gamma$, $gg$, $Z\gamma$, $ZZ$, $WW^\ast$, $t\bar{t}$ and $hh$ signals at the $750 {\rm GeV}$ resonance are only sensitive to the dilaton-Higgs mixing angle $\theta_S$ and the parameter $\eta \equiv v N_X/f$, where $f$ is the dilaton decay constant and $N_X$ denotes the number of the fermions. Then we scan the two parameters by considering various theoretical and experimental constraints to find the solutions to the diphoton excess. We conclude that the model can predict the central value of the diphoton rate without conflicting with any constraints. The signatures of our explanation at the LHC Run II and the vacuum stability at high energy scale are also discussed.