Polarization and the weak mixing angle in high energy e±e− collisions

At a linear collider of the next generation the large event rates expected from Bhabha and Møller scattering may be used to determine simultaneously sin2θw and the polarization of both beams with very high accuracy. These measurements can be performed in parallel to the other tasks of the linear collider as a free by-product. A high degree of polarization and a good polar angle coverage of the detectors turn out to be major assets.