Observation of ; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>W</mml:mi><mml:mi>Z</mml:mi><mml:mi>γ</mml:mi></mml:math>; production and constraints on new physics scenarios in proton-proton collisions at ; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>TeV</mml:mi></mml:math> | CU Experts

A measurement of the WZγ triboson production cross section is presented. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of s=13 TeV recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 138 fb−1. The analysis focuses on the final state with three charged leptons, ℓ±νℓ+ℓ−, where ℓ=e or μ, accompanied by an additional photon. The observed (expected) significance of the WZγ signal is 5.4 (3.8) standard deviations. The cross section is measured in a fiducial region, where events with an ℓ originating from a tau lepton decay are excluded, to be 5.48±1.11 fb, which is compatible with the prediction of 3.69±0.24 fb at next-to-leading order in quantum chromodynamics. Exclusion limits are set on anomalous quartic gauge couplings and on the production cross sections of massive axionlike particles.; ; ; ; ; © 2025 CERN, for the CMS Collaboration; 2025; CERN; ; ;

Chekhovsky V; Hayrapetyan A; Makarenko V; Tumasyan A; Adam W; Andrejkovic JW; Benato L; Bergauer T; Chatterjee S; Damanakis K

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