Radiative corrections to e+e- → H+H-: THDM versus MSSM

One-loop radiative corrections to e+e- → H+H- are considered at future linear collider energies, in the general type II Two Higgs Doublet Model (THDM) and in the Minimal Supersymmetric Standard Model-like (MSSM) Higgs sector. To make the comparison between THDM and MSSM tractable, we have introduced a quasi-SUSY parameterization which preserves all the tree-level Higgs mass-sum-rules of the MSSM, and involves just 3 free parameters in the Higgs 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 contribution of the model dependent h0H+H- and H0H+H- vertices to the final 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 β important effects (∼ + 30%) can be found