Standard Model Physics at LEP

TL;DR

This article reviews precision Standard Model tests performed at LEP, covering electroweak measurements at the Z0 resonance and LEP-II W physics, and QCD jet studies. It describes how cross sections, asymmetries, and radiative corrections yield precise electroweak parameters and indirect constraints on $M_t$ and $M_H$, while jet physics enables NNLO determinations and tests of asymptotic freedom via the energy evolution of $\alpha_s$. The work highlights the LEP combination’s determination of $M_{Z^0}$ to ~23 ppm, the confirmation of three light neutrino flavors, and the consistency of $W$-pair production and the $W$ mass with SM predictions, along with a comprehensive survey of jet algorithms and hadronisation models. Overall, LEP measurements provide a stringent, multi-faceted validation of the electroweak and strong sectors of the Standard Model and tightly constrain its free parameters.

Abstract

Selected topics on precision tests of the Standard Model of the Electroweak and the Strong Interaction at the LEP $e^+e^-$ collider are presented, including an update of the world summary of measurements of $α_s$, representing the state of knowledge of summer 1999. This write-up of lecture notes consists of a reproduction of slides, pictures and tables, supplemented by a short descriptive text and a list of relevant references.

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