Measurement of the Strong Coupling alpha_S from the Four-Jet Rate in e+e- annihilation

TL;DR

This paper measures the strong coupling constant alpha_S using four-jet rates in e+e- annihilation data across a range of energies, comparing results to advanced theoretical calculations.

Contribution

It provides a precise measurement of alpha_S from four-jet rates, incorporating next-to-leading order calculations with resummation, and confirms consistency with the world average.

Findings

Measured alpha_S = 0.1208 with uncertainties

Results agree with the world average of alpha_S

Demonstrates the effectiveness of four-jet rate analysis

Abstract

Data from e+e- annihilation into hadrons at centre-of-mass energies between 91 GeV and 209 GeV are used to study the four-jet rate as a function of the Durham algorithm's resolution parameter y_cut. The four-jet rate is compared to next-to-leading order calculations that include the resummation of large logarithms. The strong coupling measured from the four-jet rate is 0.1208 +-0.0006(stat.)+-0.0021(exp.)+-0.0019(had.)+-0.0024(scale) in agreement with the world average.