Measurement of Hadron and Lepton-Pair Production in e+e- Collisions at sqrt{s}=192-208GeV at LEP

TL;DR

This paper reports measurements of hadron and lepton-pair production in electron-positron collisions at energies between 192 and 208 GeV, confirming the Standard Model predictions with high precision.

Contribution

The study provides detailed cross section measurements and asymmetries for e+e- collisions at LEP energies, including differential cross sections for electron-positron pairs.

Findings

Good agreement with Standard Model predictions

Precise measurements of cross sections and asymmetries

Differential cross sections as a function of scattering angle

Abstract

Hadron production and lepton-pair production in e+e- collisions are studied with data collected with the L3 detector at LEP at centre-of-mass energies sqrt{s}=192-208GeV. Using a total integrated luminosity of 453/pb, 36057 hadronic events and 12863 lepton-pair events are selected. The cross sections for hadron production and lepton-pair production are measured for the full sample and for events where no high-energy initial-state-radiation photon is emitted prior to the collisions. Lepton-pair events are further investigated and forward-backward asymmetries are measured. Finally, the differential cross sections for electron-positron pair-production is determined as a function of the scattering angle. An overall good agreement is found with Standard Model predictions.