Corrections of Order $\alpha {\alpha }_s$ to W Boson Decays

Abstract

We present the calculation of the mixed two-loop QCD/electroweak corrections to hadronic W boson decays within the Standard Model. The optical theorem is applied to the W boson two-point function. The multi-scale integrals are computed with the help of asymptotic expansions, which factorize the three-loop diagrams into one- and two-loop vacuum and propagator-type integrals.

Comments: 36 pages, 16 figures, 5 tables; v2 accepted for publication in Nuclear Physics B; v3: typos corrected