Post-decay quantum entanglement in top pair production
J. A. Aguilar-Saavedra
Top pairs produced at the Large Hadron Collider exhibit quantum entanglement of their spins near threshold and for boosted, central ttbar pairs. The entanglement is maintained between the decay products, in particular between the top quark and the W− boson from the anti-quark (or vice-versa, between tbar and W+) in certain kinematical regions. Therefore, ttbar production provides a rare opportunity to verify the spin entanglement between a fermion and a boson. The tW entanglement can be probed at the 7σ level near threshold with Run 2 data, and at the 5σ level in the boosted region with the foreseen Run 3 luminosity. In addition, the entanglement between the two W bosons can be probed at the 4σ level at the LHC Run 3.