Pinning down electroweak dipole operators of the top quark

Abstract

We consider hadronic top quark pair production and pair production in association with a photon or a Z boson to probe electroweak dipole couplings in t[bar over b]W, t[bar over t]γ, and t[bar t]Z interactions. We demonstrate how measurements of these processes at the 13 TeV LHC can be combined to disentangle and constrain anomalous dipole operators. The construction of cross section ratios allows us to significantly reduce various uncertainties and exploit orthogonal sensitivity between the t[bar over t]γ and t[bar over t]Z couplings. In addition, we show that angular correlations in t[bar over t] production can be used to constrain the remaining t[bar over b]W dipole operator. Our approach yields excellent sensitivity to the anomalous couplings and can be a further step toward precise and direct measurements of the top quark electroweak interactions.