2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/199240Precision studies of QCD at electron-positron colliders are based on measurements of event shapes and jet rates. To match the high experimental accuracy, theoretical predictions to next-to-next-to-leading order (NNLO) in QCD are needed for a reliable interpretation of the data. We report the first calculation of NNLO corrections O(alpha_s^3) to three-jet production and related event shapes, and discuss their phenomenological impact.Contributed to 2007 Europhysics Conference on High Energy Physics, Manchester, England 19-25 July 2007High Energy Physics - Phenomenologytext