Projected Sensitivity to Top-Quark Couplings in tt̄γ and tt̄Z Production at the HL-LHC with the ATLAS Experiment

Projection studies for top quark pair production in association with a photon and a Z boson at the High Luminosity LHC (HL-LHC) are presented. They focus on the sensitivity of these processes to the electroweak couplings of the top quark, interpreted in the context of Effective Field Theories. The projections are based on extrapolations of the latest Run 2 differential cross section measurements using 140 fb⁻¹ of proton-proton collision data recorded by the ATLAS detector during Run 2 of the LHC. Assuming integrated luminosities of 2 to 3 ab⁻¹ per experiment, and two different uncertainty scenarios, the expected limits on various Effective Field Theory operators from a combination of ATLAS and CMS results are explored.