Spin correlations in top-antitop production have been studied for nearly 30 years, and related observables have been measured by the ATLAS and CMS Collaborations. Yet, a new twist on these studies is their interpretation in terms of the entanglement of the top quark and anti-quark, and in the possible violation of Bell-like inequalities that would hold if Nature did not obey quantum-mechanical rules. I will briefly review the formalism required for this interpretation, to later discuss entanglement observables, and how they can be measured in current LHC data as well as in the HL-LHC.
Organized by: Paulo Brás, Paulo Silva, Jaime Silva