Observation of $WZ\gamma$ Production in $pp$ Collisions at $\sqrt{s}=13$ TeV with the ATLAS Detector

Abstract

This Letter reports the observation of $WZ\gamma$ production and a measurement of its cross-section using 140.1 $\pm$ 1.2 fb${}^{-1}$ of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. The $WZ\gamma$ production cross-section, with both the $W$ and $Z$ bosons decaying leptonically, $pp\to WZ\gamma \to {{\ell }^{\prime }}^{\pm }\nu {\ell }^{+}{\ell }^{-}\gamma$ (${\ell }^{{(}^{\prime })}=e,\mu$), is measured in a fiducial phase-space region defined such that the leptons and the photon have high transverse momentum and the photon is isolated. The cross-section is found to be 2.01 $\pm$ 0.30 (stat.) $\pm$ 0.16 (syst) fb. The corresponding Standard Model predicted cross-section calculated at next-to-leading order in perturbative quantum chromodynamics and at leading order in the electroweak coupling constant is 1.50 $\pm$ 0.06 fb. The observed significance of the $WZ\gamma$ signal is 6.3$\sigma$, compared with an expected significance of 5.0$\sigma$.

arXiv comment28 pages in total, author list starting page 11, 2 figures, 1 table, published in Phys. Rev. Lett. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2019-17/

References in corpus (27)

• A Brief Introduction to PYTHIA 8.1
• New Generation of Parton Distributions with Uncertainties from Global QCD Analysis
• A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX
• A New Method for Combining NLO QCD with Shower Monte Carlo Algorithms
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• Parton distributions for the LHC Run II
• PDF4LHC recommendations for LHC Run II
• A parton shower algorithm based on Catani-Seymour dipole factorisation
• Event Generation with Sherpa 2.2
• QCD matrix elements and truncated showers
• Topological cell clustering in the ATLAS calorimeters and its performance in LHC Run 1
• Electron and photon performance measurements with the ATLAS detector using the 2015-2017 LHC proton-proton collision data
• Muon reconstruction and identification efficiency in ATLAS using the full Run 2 $pp$ collision data set at $\sqrt{s}=13$ TeV
• Performance of missing transverse momentum reconstruction with the ATLAS detector using proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Electron reconstruction and identification in the ATLAS experiment using the 2015 and 2016 LHC proton-proton collision data at $\sqrt{s}$ = 13 TeV
• Luminosity determination in $pp$ collisions at $\sqrt{s}=13$ TeV using the ATLAS detector at the LHC
• Electron and photon energy calibration with the ATLAS detector using 2015-2016 LHC proton-proton collision data
• Measurements of $Z\gamma$ and $Z\gamma \gamma$ production in $pp$ collisions at $\sqrt{s}=$ 8 TeV with the ATLAS detector
• A search for WW gamma and WZ gamma production and constraints on anomalous quartic gauge couplings in pp collisions at sqrt(s) = 8 TeV
• Observation of the production of three massive gauge bosons at $\sqrt{s}=$ 13 TeV
• Study of $WW\gamma$ and $WZ\gamma$ production in $pp$ collisions at $\sqrt{s}=8$ TeV and search for anomalous quartic gauge couplings with the ATLAS experiment
• Measurement of the $Z(\to {\ell }^{+}{\ell }^{-})\gamma$ production cross-section in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Measurements of $W^{+}{W}^{-}+\ge 1$jet production cross-sections in $pp$ collisions at $\sqrt{s}=13$TeV with the ATLAS detector
• Observation of $WWW$ Production in $pp$ Collisions at $\sqrt{s}=13$ TeV with the ATLAS Detector
• Measurements of the pp to W gamma gamma and pp to Z gamma gamma cross sections and limits on anomalous quartic gauge couplings at sqrt(s) = 8 TeV
• Measurement of $Z\gamma \gamma$ production in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• NLO electroweak and QCD corrections to the production of a photon with three charged lepton plus missing energy at the LHC

Cited by in corpus (6)

• Observation of WW$\gamma$ production and search for H$\gamma$ production in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Electroweak, QCD and flavour physics studies with ATLAS data from Run 2 of the LHC
• Observation of WZ$\gamma$ production and constraints on new physics scenarios in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Evidence of ZZ$\gamma$ production and observation of $4\ell \gamma$ in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Observation of tWZ production at the CMS experiment
• Gluon-gluon fusion contribution to the productions of three gauge bosons at the LHC