Evidence for Electroweak Production of $W^{\pm}W^{\pm}jj$ in $pp$ Collisions at $\sqrt{s}=8$ TeV with the ATLAS Detector

TL;DR

This paper reports the first evidence of electroweak production of same-charge $W$ boson pairs with two jets at the LHC, confirming Standard Model predictions and setting limits on anomalous couplings.

Contribution

It provides the first measurement and evidence of $W^{ ext{±}}W^{ ext{±}}jj$ production in proton-proton collisions at 8 TeV, distinguishing electroweak from strong production mechanisms.

Findings

Evidence for $W^{ ext{±}}W^{ ext{±}}jj$ production with 4.5 sigma significance.

Electroweak-only $W^{ ext{±}}W^{ ext{±}}jj$ observed with 3.6 sigma significance.

Measured cross sections agree with Standard Model predictions.

Abstract

This Letter presents the first study of $W^{\pm}W^{\pm}jj$, same-electric-charge diboson production in association with two jets, using 20.3 fb$^{-1}$ of proton--proton collision data at $\sqrt{s}=8$ TeV recorded by the ATLAS detector at the Large Hadron Collider. Events with two reconstructed same-charge leptons ($e^\pm e^\pm$, $e^\pm \mu^\pm$, and $\mu^\pm \mu^\pm$) and two or more jets are analyzed. Production cross sections are measured in two fiducial regions, with different sensitivities to the electroweak and strong production mechanisms. First evidence for $W^{\pm}W^{\pm}jj$ production and electroweak-only $W^{\pm}W^{\pm}jj$ production is observed with a significance of $4.5$ and $3.6$ standard deviations respectively. The measured production cross sections are in agreement with Standard Model predictions. Limits at 95% confidence level are set on anomalous quartic gauge couplings.