New observables for testing Bell inequalities in $W$ boson pair production

TL;DR

This paper proposes a novel method to test Bell inequalities in W boson pair production by measuring their polarization, overcoming previous challenges related to decay mode reconstruction.

Contribution

It introduces a new set of Bell observables based on W boson polarization measurements, enabling realistic tests of Bell inequalities in these systems for the first time.

Findings

New Bell observables based on W polarization

Overcomes ambiguity in decay mode reconstruction

First realistic test of Bell inequalities in W pairs

Abstract

We show that testing Bell inequalities in $W^\pm$ pair systems by measuring their angular correlation suffers from the ambiguity in kinetical reconstruction of the di-lepton decay mode. We further propose a new set of Bell observables based on the measurement of the linear polarization of the $W$ bosons, providing a realistic observable to test Bell inequalities in $W^\pm$ pair systems for the first time.