Measurements of $W^{+}{W}^{-}+\ge 1$jet production cross-sections in $pp$ collisions at $\sqrt{s}=13$TeV with the ATLAS detector

Abstract

Fiducial and differential measurements of $W^{+}{W}^{-}$ production in events with at least one hadronic jet are presented. These cross-section measurements are sensitive to the properties of electroweak-boson self-interactions and provide a test of perturbative quantum chromodynamics and the electroweak theory. The analysis is performed using proton$-$proton collision data collected at $\sqrt{s}=13$TeV with the ATLAS experiment, corresponding to an integrated luminosity of 139 fb${}^{-1}$. Events are selected with exactly one oppositely charged electron$-$muon pair and at least one hadronic jet with a transverse momentum of $p_{\mathrm{T}}>30$GeV and a pseudorapidity of $|\hat{I}\cdot |<4.5$. After subtracting the background contributions and correcting for detector effects, the jet-inclusive $W^{+}{W}^{-}+\ge 1$jet fiducial cross-section and $W^{+}{W}^{-}+$ jets differential cross-sections with respect to several kinematic variables are measured, thus probing a previously unexplored event topology at the LHC. These measurements include leptonic quantities, such as the lepton transverse momenta and the transverse mass of the $W^{+}{W}^{-}$ system, as well as jet-related observables such as the leading jet transverse momentum and the jet multiplicity. Limits on anomalous triple-gauge-boson couplings are obtained in a phase space where interference between the Standard Model amplitude and the anomalous amplitude is enhanced.

58 pages in total, author list starting page 42, 14 figures, 9 tables, submitted to JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2018-34/