Top quark and charged Higgs at the Tevatron-Run II

We shortly review the top quark decay into charged Higgs, and present new results on its production at the upgraded Tevatron. We have computed the MSSM cross-section for single charged Higgs in association with the top quark beyond the regime of on-shell t t̄ production followed by the decay t → H b,. Our results are higher than recent results in the literature. In the case where H belongs to the Higgs sector of the MSSM, we show that the leading supersymmetric radiative corrections may substantially increase the cross-section. Overall we find that the charged Higgs production process can be complementary to the neutral Higgs production processes W Φ and b b̄Φ, which have been studied under similar circumstances. Since the neutral and charged Higgs channels are enhanced in the same region of the parameter space, the simultaneous detection of all these processes could be essential for an effective experimental underpinning of the nature of these Higgs particles at the Tevatron-Run II. Updated talk presented in: Physics at Run II Workshop on Supersymmetry/Higgs, Fermilab, Nov. 1998, to appear in the proceedings.