Precision Electroweak Measurements at FCC-ee

TL;DR

The paper discusses the high-precision electroweak measurements possible at FCC-ee, including Z, W, and top quark properties, enabled by its high luminosity and energy capabilities, promising significant advances over previous experiments.

Contribution

It presents detailed prospects for electroweak measurements at FCC-ee, highlighting its potential to significantly improve the precision of key Standard Model parameters.

Findings

High-precision Z mass and width measurements achievable.

Precise W mass determination at WW threshold.

Accurate top mass measurement at t-tbar threshold.

Abstract

The prospects for electroweak precision measurements at the Future Circular Collider with electron-positron beams (FCC-ee) are discussed. The Z mass and width, as well as the value of the electroweak mixing angle, can be measured with very high precision at the Z pole thanks to an instantaneous luminosity five to six order of magnitudes larger than LEP. At centre-of-mass energies around 160 GeV, corresponding to the WW production threshold, the W mass can be determined very precisely with high-statistics cross section measurements at several energy points. Similarly, a very precise determination of the top mass can be provided by an energy scan at the $\mathrm{t \bar t}$ production threshold, around 350 GeV.