Updated Study of a Precision Measurement of the W Mass from a Threshold Scan Using Polarized $\rm{e}^-$ and $\rm{e}^+$ at ILC

TL;DR

This paper presents an updated analysis of measuring the W boson mass at the ILC using polarized electron and positron beams, emphasizing optimized scan strategies to control systematics and achieve around 2 MeV precision.

Contribution

It introduces an improved method for W mass measurement at ILC with polarized beams, highlighting the benefits of polarization and optimized scan strategies.

Findings

Potential to reach 2 MeV precision in W mass measurement.

Polarized beams significantly enhance statistical power and background control.

Further work needed on accelerator design and theoretical uncertainties.

Abstract

An updated study of measuring the W mass from a polarized threshold scan at ILC is presented with an emphasis on evaluating scan strategies that control experimental systematics. Highly longitudinally polarized beams of electrons and positrons such as are feasible at ILC offer significant advantages in terms of statistical power and in-situ control of background. Eventual experimental precision of around 2 MeV can be envisaged from this technique. Further work on both the accelerator design and theoretical uncertainties will likely be needed to take full advantage of this opportunity.