A scalar hint from the diboson excess?

TL;DR

This paper proposes a new weak singlet pseudo-scalar particle as an explanation for recent diboson excesses observed at the LHC, exploring its production and decay via anomaly-induced couplings.

Contribution

It introduces a phenomenological model where a pseudo-scalar $\, exteta_W$ explains diboson excesses through anomaly-induced couplings, linking it to composite dynamics.

Findings

The pseudo-scalar can decay into two weak bosons via anomaly couplings.

The model provides a testable example consistent with observed excesses.

Couplings relate to underlying fermion dynamics in composite models.

Abstract

In view of the recent diboson resonant excesses reported by both ATLAS and CMS Collaborations, we suggest that a new weak singlet pseudo-scalar particle, $\eta_W$, may decay into two weak bosons while being produced in gluon fusion at the LHC. The couplings to the gauge bosons can arise from a Wess-Zumino-Witten anomaly term and thus we study an effective model based on the anomaly term as a well motivated phenomenological model. In models where the pseudo-scalar arises as a composite state, the coefficients of the anomalous couplings can be related to the fermion components of the underlying dynamics. We provide an example to test the feasibility of the idea.