Optimal observables for measuring three-gauge-boson couplings in $e^+ e^- \to W^+ W^-$

TL;DR

This paper develops optimal observables to precisely measure triple-gauge-boson couplings in electron-positron collisions, enabling separate analysis of CP violation and absorptive effects, with calculated statistical errors at 500 GeV.

Contribution

It introduces optimized observables for measuring $WWZ$ and $WW\gamma$ couplings, enhancing sensitivity and allowing separate studies of CP violation and absorptive parts.

Findings

Calculated expected statistical errors at 500 GeV.

Demonstrated separation of CP violation and absorptive effects.

Provided a method for improved coupling measurements.

Abstract

Observables with optimised sensitivity to the $WWZ$ and $WW\gamma$-couplings in $e^+ e^- \to W^+ W^-$ are investigated. They allow for separate studies of CP violation and of absorptive parts in the amplitude. We have calculated expected statistical errors on extracted couplings at $\sqrt{s} = 500 GeV$, with unpolarised or longitudinally polarised beams.