CP-violating ZZh coupling at e{sup +}e{sup -} linear colliders

We study the general Higgs--weak-boson coupling with CP violation via the process e{sup +}e{sup -}{yields}f{bar f}h. We categorize the signal channels by the subprocesses of Zh production and ZZ fusion and construct four CP asymmetries by exploiting polarized e{sup +}e{sup -} beams. We find complementarity among the subprocesses and the asymmetries to probe the real and imaginary parts of the CP-violating form factor. Certain asymmetries with unpolarized beams can retain significant sensitivity to the coupling. We conclude that at a linear collider with high luminosity, the CP-odd ZZh coupling may be sensitively probed via measurements of the asymmetries.