Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP

TL;DR

This paper analyzes spin and decay-plane correlations of W bosons produced in electron-positron collisions at LEP energies, confirming Standard Model predictions through experimental data.

Contribution

It provides the first detailed measurement of W boson spin and decay-plane correlations at LEP energies, validating Standard Model predictions.

Findings

Spin correlations favor the Standard Model

Decay-plane correlations are consistent with zero

Results agree with theoretical expectations

Abstract

Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~ events. Spin correlations are favoured by data, and found to agree with the Standard Model predictions. In addition, correlations between the W-boson decay planes are studied in e+e- -> W+W- -> lnqq~ and e+e- -> W+W- -> qq~qq~ events. Decay-plane correlations, consistent with zero and with the Standard Model predictions, are measured.