Determining $\alpha_s(m_Z)$ from Thrust with Power Corrections

TL;DR

This paper refines the measurement of the strong coupling constant _s(m_Z) using thrust data, emphasizing the dijet region and power correction parametrization to improve accuracy and stability.

Contribution

It introduces a fit restricted to the dijet region and models deviations from dijet power corrections to enhance the precision of _s(m_Z) determination.

Findings

Resummation improves fit stability.

Power correction deviations contribute to uncertainty.

Dijet region focus reduces non-perturbative effects.

Abstract

We update and extend a previous N$^3$LL$^\prime$+${\cal O}(\alpha_s^3)$ strong coupling determination from thrust data. In particular, we carry out a fit with data fully restricted to the dijet region seeking to minimize the potential impact of power corrections that go beyond dijet configurations. In addition, we parametrize deviations from the dijet power correction in order to add an additional source of uncertainty in the result for $\alpha_s(m_Z)$. We also show that the inclusion of resummation is important to achieve stability with respect to varying the fit region.