2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/197226The two-loop electroweak bosonic correction to the muon lifetime and the M_W-M_Z interdependece is computed using analytical methods of asymptotic expansion. Combined with previous calculations this copmletes the full two-loop correction to $Δr$ in the Standard Model. The shift to the prediction of W-boson mass due to two-loop bosonic corrections does not exceed 1 MeV for the range of the Higgs mass from 100 to 1000 GeV.8 pp, 3 figs, LaTeX, replaced with journal versionHigh Energy Physics - Phenomenologytext