Anatomy of the ATLAS diboson anomaly

TL;DR

This paper analyzes the ATLAS diboson excesses, exploring potential new physics explanations through effective field theories and assessing their consistency with experimental data.

Contribution

It identifies two viable effective field theory models involving new vector resonances that could explain the ATLAS diboson anomalies.

Findings

Likelihood analysis favors zero events in the WZ channel

Two effective field theory models are consistent with the data

Parameter regions are identified where models fit the experimental results

Abstract

We perform a general analysis of new physics interpretations of the recent ATLAS diboson excesses over Standard Model expectations in LHC Run I collisions. Firstly, we estimate a likelihood function for the true signal in the $WW$, $WZ$, and $ZZ$ channels, finding that the maximum has zero events in the $WZ$ channel, though the likelihood is sufficiently flat to allow other scenarios. Secondly, we survey the possible effective field theories containing the Standard Model plus a new resonance that could explain the data, finding just two possibilities, viz., a vector that is either a left- or right-handed $SU(2)$ triplet. Finally, we compare these models with other experimental data and determine the parameter regions in which they provide a consistent explanation.