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$\sigma$.

28 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/

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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