$t\bar{t} + X$ PRODUCTION AT ATLAS AND CMS

Recent measurements of top-quark pair production in association with W-bosons,Z-bosons, photons and b-tagged jets are reported. The measurements are based onATLAS and CMS analyses of proton−proton collisions at the Large Hadron Colliderof 13 TeV center-of-mass energy. Inclusive and differential cross-sections ofthese rare processes are compared to Standard Model theory predictions. Theyprovide stringent tests of QCD predictions and serve as a probe for new physicsbeyond the Standard Model.