QCD coupling constant at NNLO from DIS data

TL;DR

This paper determines the QCD coupling constant at NNLO using deep inelastic scattering data, showing a slightly lower value than NLO and reduced theoretical uncertainties, thus refining our understanding of strong interactions.

Contribution

First detailed NNLO analysis of DIS data for QCD coupling, demonstrating improved precision and confirming theoretical expectations.

Findings

Measured ppa_s(M_Z^2) = 0.1167 1 0.0021 (exp) +0.0056/-0.0036 (theor)

NNLO results are slightly lower than NLO, with reduced theoretical uncertainties

Analysis confirms earlier observations of improved accuracy at NNLO

Abstract

Deep inelastic scattering data on F2 structure function from various fixed-target experiments were analyzed in the non-singlet approximation with a next-to-next-to-leading-order accuracy. The study of high statistics deep inelastic scattering data provided by BCDMS, SLAC, NMC and BFP collaborations was carried out separately for the first one and the rest, followed by a combined analysis done as well. For the coupling constant the following value \alpha_s(M_Z^2) = 0.1167 +/- 0.0021 (total exp.error) +0.0056/-0.0036(theor) was found, which in this approximation turns out to be slightly less than that obtained at the next-to-leading-order, as was generally anticipated. Ditto the theoretical uncertainties reduced with respect to those obtained in the case of the next-to-leading-order analysis thus confirming earlier observations.