Speaker
Description
Event-shape observables in $e^+e^-$ annihilation provide key constraints to QCD and for MC event-generator tuning. Among these, thrust quantifies the alignment of final states into dijet-like topologies, and has been used to extract $\alpha_s$, tune hadronization models, and study non-perturbative effects. Recent theoretical advances have renewed interest in thrust, highlighting tensions between dijet-based $\alpha_s$ extractions and world average and underscoring the utility of thrust moments in constraining both perturbative and non-perturbative contributions.
We present new measurements of thrust in hadronic Z decays at $\sqrt{s}=91.2$ GeV using archived ALEPH data and the newly released DELPHI Open Data. For ALEPH, we perform the first unbinned measurement of the $\log(1−T)$ distribution, lifting limitations from fixed binning in past results. Detector effects are corrected with an ML-assisted unbinned unfolding method, enabling fully differential studies and flexible binning choices. For DELPHI, we provide not only the first physics analysis based on the Open Data, but we also leverage the preserved detector simulation and reconstruction chain to deliver an end-to-end experimental benchmark for future precision studies with archived collider datasets. These results provide new input for precision QCD studies, modern MC tuning, and phenomenological modeling relevant also to LHC event generators.
| I read the instructions above | Yes |
|---|