2922 - łączna liczba autorów publikacji

Inclusive cross-sections for top-quark pair production in association with charm quarks are measured with proton–proton collision data at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 140 fb, collected with the ATLAS experiment at the LHC between 2015 and 2018. The measurements are performed by requiring one or two charged leptons (electrons and muons), two b-tagged jets, and at least one additional jet in the final state. A custom flavor-tagging algorithm is employed for the simultaneous identification of b-jets and c-jets. In a fiducial phase space that replicates the acceptance of the ATLAS detector, the cross-sections for and production are measured to be 1.28pb and 6.4pb, respectively. The measurements are primarily limited by uncertainties in the modeling of inclusive and production, in the calibration of the flavor-tagging algorithm, and by data statistics. Cross-section predictions from various simulations are largely consistent with the measured cross-section values, though all underpredict the observed values by 0.5 to 2.0 standard deviations. In a phase-space volume without requirements on the decay products and the jet multiplicity, the cross-section ratios of and to total production are determined to be (1.23 0.25)% and (8.8 1.3)%.