Polarimetry at a Future Linear Collider - How Precise?

TL;DR

This paper explores the importance and methods of precise electron beam polarimetry at future linear colliders, emphasizing physics motivations and potential measurement techniques including Compton scattering and Standard Model asymmetries.

Contribution

It evaluates various polarimetry options and discusses the required precision for physics analyses at future linear colliders.

Findings

Compton polarimetry is a key technique for polarization measurement.

Standard Model asymmetries can serve as alternative polarimeters.

Precision requirements depend on specific physics goals.

Abstract

At a future linear collider, a polarized electron beam will play an important role in interpreting new physics signals. Backgrounds to a new physics reaction can be reduced by choice of the electron polarization state. The origin of a new physics reaction can be clarified by measuring its polarization-dependence. This paper examines some options for polarimetry with an emphasis on physics issues that motivate how precise the polarization determination needs to be. In addition to Compton polarimetry, the possibility of using Standard Model asymmetries, such as the asymmetry in forward W-pairs, is considered as a possible polarimeter. Both e+e- and e-e- collider modes are considered.