Fermion pair production in e+e- collisions at 189-209 GeV and constraints on physics beyond the Standard Model

TL;DR

This paper reports measurements of fermion pair production in electron-positron collisions at LEP energies, confirming Standard Model predictions and setting limits on various new physics scenarios beyond the Standard Model.

Contribution

It provides detailed experimental results at 189-209 GeV and establishes constraints on multiple beyond-Standard-Model theories.

Findings

Results agree with Standard Model predictions.

Constraints on new physics scenarios such as Z' bosons and leptoquarks.

No evidence found for physics beyond the Standard Model.

Abstract

Cross sections, angular distributions and forward-backward asymmetries are presented, of two-fermion events produced in e+e- collisions at centre-of-mass energies from 189 to 209 GeV at LEP, measured with the ALEPH detector. Results for e+e-, mu+mu-, tau+tau-, qq, bb and cc production are in agreement with the Standard Model predictions. Constraints are set on scenarios of new physics such as four-fermion contact interactions, leptoquarks, Z' bosons, TeV-scale quantum gravity and R-parity violating squarks and sneutrinos.