2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/38227New studies of hadronic event shape observables in e+ e- collisions between 13 and 183 GeV CM energy have enabled the running of alpha_s to be confirmed and the validity of non-perturbative power-law corrections to be investigated. A more precise value of alpha_s(M_Z) with reduced theoretical errors has been reported from fitting 18 oriented event shape distributions measured in one experiment at the Z.3 pages, 2 figures, ICHEP Vancouver, Canada, 1998High Energy Physics - Experimenttext