The Diboson Excesses in an Anomaly Free Leptophobic Left-Right Model

TL;DR

This paper proposes an anomaly-free, leptophobic left-right model with a specific gauge symmetry to explain the ATLAS diboson excess at 2 TeV, avoiding constraints from dilepton searches and fitting experimental data.

Contribution

It introduces the first anomaly-free leptophobic left-right model with a novel gauge symmetry and vector-like quarks, providing a viable explanation for the ATLAS diboson excess.

Findings

The model can explain the ATLAS diboson excess within current experimental constraints.

The $W'$ to $WZ$ channel explains the excess when quark mixing is considered.

The $Z'$ gauge boson mass is set above 2.5 TeV to evade dilepton constraints.

Abstract

The resonant excesses around 2 TeV reported by the ATLAS Collaboration can be explained in the left-right model, and the tight constraints from lepton plus missing energy searches can be evaded if the $SU(2)_R$ gauge symmetry is leptophobic. We for the first time propose an anomaly free leptophobic left-right model with gauge symmetry $SU(3)_C \times SU(2)_L \times SU(2)_R \times U(1)_{X}$ where the SM leptons are singlets under $SU(2)_R$. The gauge anomalies are cancelled by introducing extra vector-like quarks. The mass of $Z^\prime$ gauge boson, which cannot be leptophobic, is assumed to be around or above 2.5 TeV so that the constraint on dilepton final state can be avoided. Moreover, we find that the $W^\prime \to WZ$ channel cannot explain the ATLAS diboson excess due to the tension with the constraint on $W^\prime \to jj$ decay mode. We solve this problem by considering the mixings between the SM quarks and vector-like quarks. We show explicitly that the ATLAS diboson excess can be explained in the viable parameter space of our model, which is consistent with all the current experimental constraints.