A global analysis of Energy-Energy Correlation data: determination of $\alpha_S$ and non-perturbative QCD parameters

TL;DR

This paper performs a comprehensive global analysis of Energy-Energy Correlation data in electron-positron annihilation, achieving precise determination of the strong coupling constant and non-perturbative QCD parameters across a wide energy range.

Contribution

It introduces a novel global fit combining resummed and fixed-order calculations with heavy-quark effects and non-perturbative modeling, including new datasets from ALEPH and AMY.

Findings

Precise measurement of _S(m_Z^2) = 0.119 b1 0.002

First global fit including ALEPH and AMY data

Excellent agreement with experimental data across energies

Abstract

We present a comprehensive global analysis of Energy-Energy Correlation (EEC) data in electron-positron annihilation into hadrons, spanning a wide range of center-of-mass energies ($7.7\,\,\text{GeV}\!\leq\!\sqrt{s}\!\leq\! 91.2\,\,\text{GeV})$. In the back-to-back (two-jet) region, we resum to all orders the logarithmically-enhanced contributions up to next-to-next-to-next-to-leading logarithmic (N$^3$LL) accuracy. The resummed results are consistently matched to fixed-order calculations up to $\mathcal{O}(\alpha_S^3)$. Our resummation formalism also incorporates dominant heavy-quark mass effects and models non-perturbative power corrections by means of an analytic dispersive approach. A simultaneous fit yields an excellent description of experimental data across all energies, enabling a precise determination of the strong coupling, $\alpha_S(m_Z^2) = 0.119 \pm 0.002$, as well as the non-perturbative parameters, including those characterizing the Collins--Soper evolution kernel. Our analysis includes, for the first time in a global fit, datasets from the ALEPH and AMY collaborations.