Yukawa coupling corrections to the decay $H^+ \to W^+ A^0$

We compute the fermionic radiative contributions to the decay $H^+ \to W^{+(*)} A^0$ in the framework of models with two Higgs doublets (2HDM), for the case of an on-shell and off-shell W. We show that, in the majority of the cases, current measurements of the $\rho$ parameter suggest $M_{H^{\pm}}\ge M_A$ and such decays could invalidate current charged Higgs searches or aid detection in the region $M_{H^{\pm}}\approx M_W$. We find that the radiative corrections may approach 50% for small values of $\tan\beta$.