Power corrections in the dispersive model for a determination of the strong coupling constant from the thrust distribution

TL;DR

This paper advances the dispersive model for thrust distribution by including NNLO corrections and bottom quark mass effects, enabling a precise extraction of the strong coupling constant from experimental data across various energies.

Contribution

It extends the dispersive model to NNLO with renormalon subtraction and incorporates bottom quark mass effects for improved analysis of thrust data.

Findings

Determined s(M_Z) = 0.1131^{+0.0028}_{-0.0022}

Extracted (2 GeV) = 0.538^{+0.102}_{-0.047}

Analyzed data from  to 206 GeV with improved theoretical accuracy.

Abstract

In the context of the dispersive model for non-perturbative corrections, we extend the leading renormalon subtraction to NNLO for the thrust distribution in $e^+e^-$ annihilation. Within this framework, using a NNLL+NNLO perturbative description and including bottom quark mass effects to NLO, we analyse data in the centre-of-mass energy range $\sqrt{s}=14-206$ GeV in view of a simultaneous determination of the strong coupling constant and the non-perturbative parameter $\alpha_0$. The fits are performed by matching the resummed and fixed-order predictions both in the R and the log-R matching schemes. The final values in the R scheme are $\alpha_s(M_Z) = 0.1131^{+0.0028}_{-0.0022}$, $\alpha_0(2 {\rm GeV}) = 0.538^{+0.102}_{-0.047}$.