750 GeV Diphoton Resonance from Singlets in an Exceptional Supersymmetric Standard Model

TL;DR

This paper explores the possibility that a 750 GeV diphoton resonance could be explained by singlet scalars or pseudoscalars within an extended E_6 supersymmetric model, predicting new particles observable at LHC Run 2.

Contribution

It introduces a variant of the E_6SSM with three singlets, explaining the resonance and predicting associated new particles and their collider signatures.

Findings

Predicts two scalar and two pseudoscalar states around 750 GeV

Calculates branching ratios and cross-sections for these states

Suggests new particles like Z'_N, D, ar{D}, and charged Higgsinos at LHC

Abstract

The 750-760 GeV diphoton resonance may be identified as one or two scalars and/or one or two pseudoscalars contained in the two singlet superfields S_{1,2} arising from the three 27-dimensional representations of E_6 . The three 27s also contain three copies of colour-triplet charge \mp 1/3 vector-like fermions D,\bar{D} and two copies of charged inert Higgsinos \tilde{H}^{+},\tilde{H}^{-} to which the singlets S_{1,2} may couple. We propose a variant of the E_6SSM where the third singlet S_3 breaks a gauged U(1)_N above the TeV scale, predicting Z'_N, D,\bar{D}, \tilde{H}^{+},\tilde{H}^{-} at LHC Run 2, leaving the two lighter singlets S_{1,2} with masses around 750 GeV. We calculate the branching ratios and cross-sections for the two scalar and two pseudoscalar states associated with the S_{1,2} singlets, including possible degeneracies and maximal mixing, subject to the constraint that their couplings remain perturbative up to the unification scale.