2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/226624I report on recent results for the total production cross section of the process e- e+ -> mu- nubar_mu u dbar X near the W-pair production threshold up to next-to-leading order in GammaW/MW alpha v^2 obtained in the framework of unstable-particle effective field theory. Remaining theoretical uncertainties and their impact on the experimental determination of the W mass are discussed.To appear in the proceedings of the 8th International Symposium on Radiative Corrections, October 1-5, 2007, Florence, ItalyHigh Energy Physics - Phenomenologytext