Study of and production in collisions at and search for anomalous quartic gauge couplings with the ATLAS experiment

This paper presents a study of $$ and $$ triboson production using events from proton-proton collisions at a centre-of-mass energy of $$ recorded with the ATLAS detector at the LHC and corresponding to an integrated luminosity of 20.2 fb $$ . The $$ production cross-section is determined using a final state containing an electron, a muon, a photon, and neutrinos ( $$ ). Upper limits on the production cross-section of the $$ final state and the $$ and $$ final states containing an electron or a muon, two jets, a photon, and a neutrino ( $$ or $$ ) are also derived. The results are compared to the cross-sections predicted by the Standard Model at next-to-leading order in the strong-coupling constant. In addition, upper limits on the production cross-sections are derived in a fiducial region optimised for a search for new physics beyond the Standard Model. The results are interpreted in the context of anomalous quartic gauge couplings using an effective field theory. Confidence intervals at 95% confidence level are derived for the 14 coupling coefficients to which $$ and $$ production are sensitive.