$\alpha_s$ determination at NNLO$^\star$+NNLL accuracy from the energy evolution of jet fragmentation functions at low $z$

TL;DR

This paper determines the strong coupling constant $_s$ at NNLO$^*$+NNLL accuracy by analyzing the energy evolution of jet fragmentation functions at low $z$, achieving results consistent with the world average.

Contribution

It introduces a novel extraction of $_s$ from the energy evolution of fragmentation functions at NNLO$^*$+NNLL accuracy, improving precision and agreement with global averages.

Findings

_s(m_Z) = 0.1205 b1 0.0010 (stat) b1 0.0022 (theory)

Results are in excellent agreement with the current world average.

Method provides a precise determination of _s from jet fragmentation data.

Abstract

The QCD coupling $\alpha_s$ is extracted from the energy evolution of the first two moments (multiplicity and mean) of the parton-to-hadron fragmentation functions at low fractional hadron momentum $z$. Comparisons of the experimental $e^+e^-$ and deep-inelastic $e^\pm$p jet data to our NNLO$^*$+NNLL predictions, allow us to obtain $\alpha_s(m_{_{\rm Z}})$ = 0.1205$\pm$0.0010$^{+0.0022}_{-0.0000}$, in excellent agreement with the current world average determined using other methods at the same level of accuracy.