THE W-WIDTH IN THE 2 HIGGS DOUBLET MODEL

The electroweak 1-loop corrections to the decay width of the W boson i nto fermions Gamma(W+ --> f(1) ($) over bar f(2)) are discussed in the extended Higgs sector of the general two Higgs doubler model without any constraint. The relative corrections to the decay W+ --> e(+)nu(e) which come exclusively from W boson propagator are unobservably small in the whole parameter region with the maximal correction of -6 x 10( -3)%. Due to the increasing of the Yukawa couplings with fermion masse s, the relative corrections to the decays W+-->tau(+)nu(tau) and W+ -- > c ($) over bar s become larger, but even after having raised the Yuk awa couplings with help of tan beta, the maximal corrections lie under the percent region and thus give also no observable effect. We discus s also the Higgs sector of the minimal supersymmetric standard model f or the decays W+ --> tau(+)nu(tau) and W+ --> cs. Similarly to the cas es in the general two Higgs doublet model, the corrections in this mod el give no sizable effect and hence are not significant.