Combination procedure for the precise determination of Z boson parameters from results of the LEP experiments

TL;DR

This paper presents a combination procedure for precisely determining Z boson parameters using measurements from four LEP experiments, enabling high-precision tests of electroweak theory.

Contribution

It introduces a novel combination method for Z boson parameters derived from multiple experiments at LEP, improving the accuracy of electroweak measurements.

Findings

Combined Z boson mass and width with reduced uncertainties

Enhanced precision in hadronic cross-section measurements

Improved consistency among LEP experiment results

Abstract

The precise determination of the Z boson parameters from the measurements at the Z resonance by the four collaborations ALEPH, DELPHI, L3 and OPAL in e+e- collisions at the large electron positron collider LEP at CERN is a landmark for precision tests of the electroweak theory. The four experiments measured quantities which were used to extract the mass and width of the Z boson, the hadronic cross-section at the pole of the resonance, the ratio of hadronic and leptonic decay widths, and the leptonic forward-backward asymmetries at the pole. The combination procedure based on these parameters is presented in this paper.