Anatomy of the ATLAS diboson anomaly

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 in terms of the truth signal in the WW, WZ, and ZZ channels, finding that the maximum has zero events in the WZ channel, though the likelihood is sufficiently at 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, identifying 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.