A new proposal for diphoton resonance from $E_6$ motivated extra $U(1)$

TL;DR

This paper proposes a new explanation for the 750 GeV diphoton resonance observed at the LHC, involving vector-like quarks and scalar singlets motivated by $E_6$ symmetry, predicting additional signals for future detection.

Contribution

It introduces a novel model linking $E_6$ motivated particles to the diphoton excess, predicting correlated dijet and four-jet signals at the same mass scale.

Findings

Predicts a diphoton resonance from vector-like quark decays.

Foresees accompanying dijet signals at the same mass.

Suggests large cross-section for four-jet final states.

Abstract

We propose that the diphoton resonance signal indicated by the recent LHC data might also arise from the pair productions of vector-like heavy down-type quarks with mass around $750$ GeV and above. The vector-like quark decays into an ordinary light quark and a Standard Model singlet scalar. The subsequent decay of scalar singlet produces the diphoton excess. Both the vector-like quark and singlet scalars appear naturally in the $E_6$, and their masses can be in the TeV scale with a suitable choice of symmetry breaking pattern. The prediction of such a proposal would be to see an accompanying dijet signal at the same mass with similar cross section in the $2\gamma + 2j$ final state and two dijet resonances at the same mass for a $4j$ final state with a cross section, about 100 times larger. Both predictions can be tested easily as the luminosity accumulates in the upcoming runs of the LHC.