$\alpha_s$ 2002

TL;DR

This paper updates measurements of the strong coupling constant $oldsymbol{_s}$ as of September 2002, confirming its energy dependence and providing a new world average consistent with Quantum Chromodynamics predictions.

Contribution

It presents the latest experimental results and a new world average of $oldsymbol{_s}$ at the $Z^0$ boson mass, based on NNLO QCD calculations.

Findings

Energy dependence of $oldsymbol{_s}$ confirmed

New world average $oldsymbol{_s(M_Z)}$ = 0.1183 ± 0.0027

Results agree with QCD expectations

Abstract

An update of measurements of the strong coupling constant $\alpha_s$ is given, representing the status of September 2002. The results convincingly prove the energy dependence of $\alpha_s$ and are in excellent agreement with the expectations of Quantum Chromodynamics, QCD. Evolving all results to the rest energy of the $Z^0$ boson, the new world average of $\alpha_s(M_Z)$ is determined from measurements which are based on QCD calculations in complete NNLO perturbation theory, giving $$ \alpha_s(M_Z) = 0.1183 \pm 0.0027 . $$