2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/43409We briefly illustrate the impact of the genuinely weak one-loop virtual terms of the ${\cal O}(α_{\rm S}α_{\rm EW}^3)$ factorisable corrections to the three-jet cross section at $\sqrt s=M_Z$. Their importance for the measurement of $α_{\rm S}$ at GigaZ luminosities is emphasised14 pages, LaTeX, 6 figures (talk given at the ECFA Study of Physics and Detectors for a Linear Collider, Montpellier, France, 13-16 November 2003)High Energy Physics - Phenomenologytext