Search for anomalous electroweak production of $WW/WZ$ in association with a high-mass dijet system in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector

TL;DR

This paper searches for signs of anomalous quartic gauge couplings in vector-boson scattering events at the LHC, setting limits on new physics parameters using 8 TeV collision data and advanced jet reconstruction techniques.

Contribution

It introduces a novel analysis of $WW/WZ$ production with high-mass dijets, constraining anomalous gauge couplings with improved jet substructure methods.

Findings

Set 95% CL limits on $\alpha_4$ and $\alpha_5$

Used jet substructure to identify hadronic $W/Z$ decays

Analyzed 20.2 fb$^{-1}$ of 8 TeV data

Abstract

A search is presented for anomalous quartic gauge boson couplings in vector-boson scattering. The data for the analysis correspond to $20.2$ fb$^{-1}$ of $\sqrt{s}=8$ TeV $pp$ collisions, and were collected in 2012 by the ATLAS experiment at the Large Hadron Collider. The search looks for the production of $WW$ or $WZ$ boson pairs accompanied by a high-mass dijet system, with one $W$ decaying leptonically, and a $W$ or $Z$ decaying hadronically. The hadronically decaying $W/Z$ is reconstructed as either two small-radius jets or one large-radius jet using jet substructure techniques. Constraints on the anomalous quartic gauge boson coupling parameters $\alpha_4$ and $\alpha_5$ are set by fitting the transverse mass of the diboson system, and the resulting 95% confidence intervals are $-0.024<\alpha_4<0.030$ and $-0.028<\alpha_5<0.033$.