The LHC diphoton resonance from gauge symmetry

TL;DR

This paper proposes a gauge symmetry-based model to explain the 750 GeV diphoton excess observed at the LHC, introducing a new scalar and vector-like fermions within a unified framework.

Contribution

It presents a complete gauge symmetry model that naturally incorporates the necessary particles and interactions to account for the diphoton resonance.

Findings

The model can produce the observed diphoton excess.

Vector-like quarks emerge naturally from the gauge symmetry.

The framework offers a consistent explanation for the resonance.

Abstract

Motivated by what is possibly the first sign of new physics seen at the LHC, the diphoton excess at $750$ GeV in ATLAS and CMS, we present a model that provides naturally the necessary ingredients to explain the resonance. The simplest phenomenological explanation for the diphoton excess requires a new scalar state, $X(750)$, as well as additional vector-like (VL) fermions introduced in an ad-hoc way in order to enhance its decays into a pair of photons and/or increase its production cross-section. We show that the requiered VL quarks and their couplings can emerge naturally from a complete framework based on the $SU(3)_L \otimes U(1)_\mathcal{X}$ gauge symmetry.