Analysis note: measurement of thrust in $e^{+}{e}^{-}$ collisions at $\sqrt{s}$ = 91 GeV with archived ALEPH data

Abstract

A measurement of the thrust distribution in $e^{+}{e}^{-}$ collisions at $\sqrt{s}=91.2$ GeV with archived data from the ALEPH experiment at the Large Electron-Positron Collider is presented. The thrust distribution is reconstructed from charged and neutral particles resulting from hadronic $Z$-boson decays. For the first time with $e^{+}{e}^{-}$ data, detector effects are corrected using a machine learning based method for unbinned unfolding. The measurement provides new input for resolving current discrepancies between theoretical calculations and experimental determinations of $\hat{I}{\pm }_s$, constraining non-perturbative effects through logarithmic moments, developing differential hadronization models, and enabling new precision studies using the archived data.