Measurement of the $WW+WZ$ cross section and limits on anomalous triple gauge couplings using final states with one lepton, missing transverse momentum, and two jets with the ATLAS detector at $\sqrt{\rm{s}} = 7$ TeV

TL;DR

This paper measures the combined WW+WZ production cross section at 7 TeV using ATLAS data, finds results consistent with the Standard Model, and sets limits on anomalous gauge couplings through dijet transverse momentum analysis.

Contribution

First measurement of WW+WZ cross section at 7 TeV with ATLAS, including limits on anomalous gauge couplings using dijet momentum distributions.

Findings

Measured WW+WZ cross section: 68 ± 7 (stat) ± 19 (syst) pb

Observed significance of 3.4σ for combined production

Set limits on anomalous triple gauge couplings

Abstract

The production of a $W$ boson decaying to $e\nu$ or $\mu\nu$ in association with a $W$ or $Z$ boson decaying to two jets is studied using $4.6 \mathrm{fb}^{-1}$ of proton--proton collision data at $\sqrt{\rm{s}} = 7$ TeV recorded with the ATLAS detector at the LHC. The combined $WW+WZ$ cross section is measured with a significance of 3.4$\sigma$ and is found to be $68 \pm 7 \ \mathrm{(stat.)} \pm 19 \ \mathrm{(syst.)} \ pb$, in agreement with the Standard Model expectation of $61.1 \pm 2.2 \ \mathrm{pb}$. The distribution of the transverse momentum of the dijet system is used to set limits on anomalous contributions to the triple gauge coupling vertices and on parameters of an effective-field-theory model.