2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/39860The new version 6.1 of the HERWIG event generator allows one to simulate hadronic final states in electron-positron annihilations using the $O(α_s^2)$ partonic matrix elements (MEs) for $e^+e^-\to q\bar qgg$ and $e^+e^-\to q\bar q Q\bar Q$. The consequent phenomenology is discussed in the case of four-jet signatures of particular relevance to future electron-positron Linear Colliders (LCs), such as in Higgs boson searches. The new approach adopted in HERWIG is compared to the standard $O(α_s)$ description, as well as to other recently presented event generators also based on $e^+e^-\to4$ parton MEs.9 pages, latex, 4 figures (talk given at the 2nd ECFA/DESY Study on Physics and Detectors for a Linear Electron-Positron Collider, Padova, Italy, 4-8 May 2000): LC note number and reference added, one typo correctedHigh Energy Physics - Phenomenologytext