Impact of polarized $e^-$ and $e^+$ beams at a future Linear Collider and a $Z$-factory. Part I: Fundamentals in polarization and electroweak precision physics

The main goal of new physics searches at a future Linear Collider is the precise determination of the underlying new physics model. The physics potential of the ILC as wellas the multi-TeV option collider CLIC have to be optimized with regard to expected results b from the LHC. The exploitation of spin effects plays a crucial role in this regard. After ashort status report of the Linear Collider design and physics requirements, this article explains fundamentals in polarization and provides an overview of the impact of these spin effects inelectroweak precision physics. The gain of polarized beams in physics searches beyond the Standard Model, however, is summarized in part II [1]