Probing new physics in Higgs couplings to fermions using an angular analysis

The standard-model Higgs boson couples to quarks through a parity-even scalar Hqq¯ coupling. We show that the rare Higgs decay H→VZH→VZ, where V   is a vector quarkonium state such as J/ψJ/ψ (cc¯) or ϒ(1S)ϒ(1S) (bb¯), can be used to search for the presence of a parity-odd pseudoscalar Hqq¯ coupling. Since both V and Z   can decay to a pair of charged leptons, this presents an experimentally-clean channel that can be observed at the high-luminosity LHC or a future hadron collider. The P-even and P-odd Hqq¯ couplings can be measured by analyzing the angular distribution of the final-state leptons.