Constraints on Extra Neutral Gauge Bosons from W+W- Production at the ILC

Abstract

We discuss the potential of the International Linear Collider (ILC) to probe Z-Z' mixing and Z' mass by the reaction e+e- → W+W- with longitudinally polarized e+e- beams. We perform here a generic analysis of the deviations of the differential cross section from the Standard Model prediction, and apply it to a specific class of extended weak gauge models called as 'minimal-Higgs' models. Results indicate that the corresponding bounds expected from the ILC(0.5 TeV) complement the present ones obtained from low energy electroweak data, and rapidly become quite stringent at the higher energy of the ILC(1 TeV). Also, we emphasize the importance of initial beam polarization in improving the sensitivity to Z -Z' mixing.