Fermion-pair Production above the Z and Search for New Phenomena

TL;DR

This paper reviews LEP measurements of fermion-pair production at energies 130-183 GeV, summarizes searches for new physics phenomena, and reports no deviations from the Standard Model, setting new limits.

Contribution

It provides a comprehensive summary of experimental results and limits on new physics from LEP at energies above the Z boson mass.

Findings

No evidence for deviations from the Standard Model

New limits set on contact interactions and compositeness

Constraints on R-parity violating particles and Z' bosons

Abstract

A review of the measurements of hadron, flavour-tagged and lepton-pair production cross-sections and lepton-pair forward-backward asymmetries performed by the four LEP experiments ALEPH, DELPHI, L3 and OPAL at energies between 130 and 183 GeV is given. All 183 GeV results are preliminary. The searches by the four collaborations for new physics phenomena like contact interactions and compositeness, exchange of R-parity violating sneutrinos or squarks, leptoquarks or additional heavy gauge bosons Z' are summarized. No evidence for deviations from the Standard Model expectations is found and new or improved limits are derived.