LHC diphoton 750 GeV resonance as an indication of $SU(3)_c\times SU(3)_L\times U(1)_X$ gauge symmetry

TL;DR

This paper explores the possibility that a 750 GeV diphoton excess observed at the LHC could be explained by a scalar particle within an extended gauge symmetry model, involving new fermions mediating its interactions.

Contribution

It proposes a specific $SU(3)_c\times SU(3)_L\times U(1)_X$ model where a scalar explains the diphoton excess via vector-like fermions.

Findings

The scalar can produce the observed diphoton signal.

Interactions are mediated by anomaly-free vector-like fermions.

The model aligns with current experimental data.

Abstract

The LHC collaborations ATLAS and CMS recently reported on the excess of the events in the diphoton final states at the invariant mass of about $750~ \text{GeV}$. In this article we speculate on the possibility that the excess arises from the neutral CP-even component $\phi$ of the scalar triplet $ \Phi $ of the $SU(3)_{c}\times SU(3)_{L}\times U(1)_{X}$ $(3\text{-}3\text{-} 1)$ model that has a $U(1)_{X}$ charge equal to $X=-1/3$ and acquires a vacuum expectation value larger than the electroweak symmetry breaking scale. The interactions of the scalar field $\phi$ to the photon- and gluon-pairs are mediated by the virtual vector-like fermions which appear as components of the anomaly-free chiral fermion representations of the $3\text{ -}3\text{-}1$ gauge group.