e^+ e^- -> 3 jets and event shapes at NNLO

TL;DR

This paper presents NNLO calculations for 3-jet cross sections and event shape distributions in electron-positron annihilation, improving theoretical predictions and consistency with experimental data.

Contribution

It provides the first NNLO corrections for these observables, enhancing the precision of QCD predictions and the extraction of the strong coupling constant.

Findings

NNLO corrections are sizable and vary across observables.

Inclusion of NNLO improves agreement with experimental data.

Extraction of α_s is more consistent at NNLO.

Abstract

We report on the calculation of NNLO corrections to the 3-jet cross section and related event shape distributions in electron-positron annihilation. The corrections are sizable for all variables, however the magnitude of the corrections is substantially different for different observables. We observe that inclusion of the NNLO corrections yields a considerably better agreement between theory and experimental data both in shape and normalization of the event shape distributions in the region where the perturbative result is expected to hold. A new extraction of $\alpha_{s}$ using the event shape variables up to NNLO yields a considerably better consistency between the observables indicating a stabilization of the perturbative corrections at this order.