Tripartite entanglement in H→ZZ,WW decays

Abstract

The decays of the Higgs boson produce a state in which the spins of the decay products and the orbital angular momentum (L) are highly entangled. We obtain the tripartite density operator, as well as reduced operators, for the decay into two weak bosons. For H→ZZ in the four-lepton final state we also estimate the statistical sensitivity at the Large Hadron Collider and future upgrades, using a binned method to reconstruct the density operators from distributions. With the expected Run 3 data, establishing genuine tripartite entanglement would be possible beyond the 5σ level. The violation of Bell inequalities involving the spins of the two weak bosons could also be established beyond the 5σ level. Published by the American Physical Society 2024