Universal Renormalization in Leptonic and Semileptonic Amplitudes

By use of the Ward identities of current algebra, it is shown in the context of a class of ${\mathrm{SU}\mathrm{}\left(2\right)\mathrm{}}_L\otimes \mathrm{U}\mathrm{}\left(1\right)\mathrm{}$ gauge models that, after renormalization of strong coupling constants and masses, the divergent part of the corrections of order $\alpha$ to the semileptonic and leptonic amplitudes mediated by the $W$ meson is a universal multiple of the zeroth-order amplitude, independent of the strong interactions. Furthermore this divergent part can be absorbed by a universal renormalization of the $W$ coupling constant $g$.