Hayrapetyan, A.Tumasyan, A.Adam, W.Andrejkovic, J.W.Bergauer, T.Chatterjee, S.Damanakis, K.Gürpınar Güler, EmineGüler, Yalçın2024-04-202024-04-2020240031-90071079-7114https://doi.org/10.1103/PhysRevLett.132.121901https://hdl.handle.net/20.500.13091/5387The observation of WWγ production in proton-proton collisions at a center-of-mass energy of 13 TeV with an integrated luminosity of 138 fb−1 is presented. The observed (expected) significance is 5.6 (5.1) standard deviations. Events are selected by requiring exactly two leptons (one electron and one muon) of opposite charge, moderate missing transverse momentum, and a photon. The measured fiducial cross section for WWγ is 5.9 0.8ðstatÞ 0.8ðsystÞ 0.7ðmodelingÞ fb, in agreement with the next-to-leading order quantum chromodynamics prediction. The analysis is extended with a search for the associated production of the Higgs boson and a photon, which is generated by a coupling of the Higgs boson to light quarks. The result is used to constrain the Higgs boson couplings to light quarks. © 2024 CERN, for the CMS Collaboration.eninfo:eu-repo/semantics/openAccessBosonsTellurium compoundsA-centerCenter-of-mass energiesCentre-of-mass energiesHiggs bosonIntegrated luminosityLight quarksOpposite chargeProton proton collisionsStandard deviationTransverse momentaPhotonsArticle10.1103/PhysRevLett.132.1219012-s2.0-85188337355