CP-VIOLATION AND T-ODD EFFECTS AT LEP-II

LEP-II will be a tool to study CP-violation in processes involving vector bosons, and will test in particular the CP properties of the coupling of photons and Z's to W-pairs. While it is difficult to observe truly CP-odd effects, it is easy to measure T-odd ones. The latter can originate from CP-violation, or from radiative corrections involving the absorptive part of the scattering amplitude. T-odd effects are interesting in themselves, in that they accurately test the standard model and are sensitive to its unmeasured ingredients, such as the WW --> WW scattering amplitude or the masses of the top quark and the elementary scalar. The prediction of the standard T-odd effects is a necessary stepping stone in the search for an honest-to-goodness violation of CP in the pure gauge sector. We thoroughly analyse the T-odd observables in the e+e- --> W+W- process within the standard model, as well as the extra effects to be expected if the gamma-W+W- and/or ZW+W- vertices were to violate CP in a non-standard fashion.