Transverse polarization in <Emphasis Type="Italic">γZ,H Z</Emphasis> production

With the use of transverse polarization (TP), a CP-odd and T-odd observable can be constructed when the final-state particles are self-conjugate. In the case of HZ production, this observable can be used to probe a certain effective four-point e ⁺ e ⁻ ZH CP-violating coupling, not accessible without TP. Effective CP-violating ZZH coupling does not contribute to this observable. A similar observable in γZ production can be used to probe e ⁺ e ⁻ γZ four-point couplings.