Determining $\alpha_s$ at NNLO from Event Shape Data

TL;DR

This paper presents multiple NNLO methods to determine the strong coupling constant from event shape data in e+e- annihilation, combining NNLO calculations with resummation and analyzing hadronisation effects.

Contribution

It introduces new NNLO determination techniques for $
_s$ from event shapes, integrating resummation and non-perturbative corrections.

Findings

Consistent $
_s$ values obtained across different methods.

Hadronisation corrections significantly impact the $
_s$ extraction.

Enhanced precision in $
_s$ measurement from combined NNLO and resummation analysis.

Abstract

We report on several methodologically different NNLO determinations of the strong coupling constant from event shapes and related observables in e+e- annihilation. The event shape distributions are analyzed within a combined framework of NNLO and NNLA resummation. We also investigate the role of hadronisation corrections, using both Monte Carlo generator predictions and analytic models to parametrise non-perturbative power corrections.