Constraining a CP-violating WWV coupling from the W^+W^- threshold cross section at LEP2

The most general form of the $WWZ$ and $WW\gamma$ interaction contains a $CP$-violating term which has the same threshold behaviour as the Standard Model \ee \to \ww cross section. We calculate the cross section as a function of the corresponding anomalous coupling, and estimate the bounds which can be obtained from a measurement of the threshold cross section at LEP2. We show how the effect of the coupling is most pronounced in the angular distributions of the final-state fermions.Comment: 7 pages, LaTeX file, 5 ps figure