We investigate the CP-violating form factor of the ZZZ and ZZγ vertices in the pair production of ${\mathit{Z}}^0$ bosons. Useful observables in azimuthal distributions are constructed to probe CP nonconservation which may originate from these vertices. A simple two-Higgs-doublet model of CP violation is used as an illustration.

• Received 30 September 1994

DOI:https://doi.org/10.1103/PhysRevD.51.1326