Determination of the strong coupling constant from the CLEO measurement of the total hadronic cross section in $e^+e^-$ annihilation below 10.56 GeV

TL;DR

This paper determines the strong coupling constant alpha_s at the Z boson mass scale using recent CLEO measurements of the total hadronic cross section in electron-positron annihilation below 10.56 GeV, incorporating quark mass effects and effective theory matching.

Contribution

It provides a new alpha_s value derived from CLEO data that accounts for quark mass effects and proper theory matching, differing from previous CLEO III results.

Findings

Derived alpha_s(M_Z^2)=0.110 with uncertainties

Combined analysis yields alpha_s(M_Z^2)=0.119 with uncertainties

Results are consistent with the current world average

Abstract

Using recent CLEO III results for the cross section for $e^+e^- \to {\rm hadrons}$ at seven centre-of-mass energies between 6.964 and 10.538 GeV, we derive a value for the strong coupling constant $\alpha_s(M_Z^2)=0.110_{-0.012}^{-0.010}{}_{-0.011}^{+0.010}$ where the uncertainties are uncorrelated and correlated, respectively. Our result differs significantly from the one derived by CLEO III, as a consequence of inclusion of quark mass effects and the proper matching between the effective theories with four and five flavours. Combining this new result with an analysis based on earlier cross section measurements in the energy region between 2 and 10.6 GeV, we obtain $\alpha_s(M_Z^2)=0.119^{+0.009}_{-0.011}$, well consistent with the current world average.