A Measurement of $\alpha_s(M_Z^2)$ from the Gross Llewellyn Smith Sum Rule

TL;DR

This paper measures the strong coupling constant _s at the Z boson mass scale using the Gross Llewellyn Smith sum rule across various Q^2 values, comparing experimental data with perturbative QCD predictions.

Contribution

It provides a new determination of _s(M_Z^2) by combining neutrino and deep-inelastic scattering data and analyzing its Q^2 dependence within the framework of perturbative QCD.

Findings

_s(M_Z^2) determined from sum rule data

Q^2 dependence of _s consistent with QCD predictions

Greater sensitivity to _s at low Q^2 due to larger _s values

Abstract

The Gross Llewellyn Smith sum rule has been measured at different values of four-momentum transfer squared ($Q^{2}$) by combining the precise CCFR neutrino data with data from other deep-inelastic scattering experiments at lower values of $Q^{2}$. A comparison with the ${\cal O}(\alpha^{3}_{s})$ predictions of perturbative QCD yields a determination of $\alpha_{s}$ and its dependence on $Q^{2}$ in the range $1\,GeV^2 < Q^{2} < 20 \,GeV^{2}$. Low \qsq\ tests have greater sensitivity to \alfs(\mztwo) than high \qsq\ tests, since at low $Q^2$, $\alpha_s$ is large and changing rapidly.