PUB - Publikationen an der Universität Bielefeld

Within the SU(2)L x U(1) electroweak theory, by combining (bosonic) vacuum polarization with vertex and box contributions, we derive gauge-invariant (one-loop) dressed propagators for the W +/--boson and the gamma-W3 system in a straightforward manner. By introducing running couplings and masses, the corresponding four-fermion amplitudes are cast into a Born term form. The subsequent "direct renormalization" expresses the running quantities in terms of their values at a chosen scale. Among other things, the value of DELTA-r is rederived, and a comparison of our procedure and results with the results in the literature is carried out. Care is taken to give a transparent presentation of all physically relevant steps.