Radiative corrections to e(+)e(-) -> H+H-: THDM versus MSSM

One-loop radiative corrections to e(+)e(-) --> H+H- are considered at futur e linear collider energies, in the general type II Two Higgs Doublet Model (THDM) and in the Minimal Supersymmetric Standard Model-like (MSSM) Higgs s ector. To make the comparison between THDM and MSSM tractable, we have intr oduced a quasi-SUSY parameterization which preserves all the tree-level Hig gs mass-sum-rules of the MSSM, and involves just 3 free parameters in the H iggs sector (instead of 7 in the general THDM) and comprises the MSSM as a particular case. The model-independent soft photon contribution is isolated and shown to be substantial. Important effects come also from the contribu tion of the model dependent h(0)H(+)H(-) and (HH+H-)-H-0 vertices to the fi nal state, In the MSSM, the contribution of the Higgs sector is moderate (a few percent) while in the THDM and both for small and large tan beta impor tant effects (similar to +30%) can be found. (C) 1999 Published by Elsevier Science B.V. All rights reserved.