A measurement of $alpha_s(Q^2)$ from the Gross-Llewellyn Smith Sum Rule

TL;DR

This paper measures the strong coupling constant alpha_s at low Q^2 using the Gross-Llewellyn Smith sum rule, combining neutrino scattering data and comparing with advanced QCD predictions to test perturbative QCD.

Contribution

It provides a new determination of alpha_s at the Z-boson mass scale from neutrino scattering data, with improved theoretical precision at low Q^2.

Findings

Alpha_s(M_Z) = 0.114 with uncertainties

Consistent with perturbative QCD predictions

Demonstrates low Q^2 testing of QCD

Abstract

We extract a set of values for the Gross-Llewellyn Smith sum rule at different values of 4-momentum transfer squared ($Q^{2}$), by combining revised CCFR neutrino data with data from other neutrino deep-inelastic scattering experiments for $1 < Q^2 < 15 GeV^2/c^2$. A comparison with the order $\alpha^{3}_{s}$ theoretical predictions yields a determination of $\alpha_{s}$ at the scale of the Z-boson mass of $0.114 \pm^{.009}_{.012}$. This measurement provides a new and useful test of perturbative QCD at low $Q^2$, because of the low uncertainties in the higher order calculations.