Fermion and sfermion effects in e+ e− charged Higgs pair production

Top and bottom one-loop corrections to e+ e− → H+ H− are considered at NLC energies and found to be significantly large and negative over the full range of tan β. Moreover, loop effects of moderately heavy squarks and sleptons in the minimal supersymmetric extension of the standard model, tend to cancel partly or fully these large corrections, thus providing a useful indirect information about the supersymmetric sector. The overall effect can still range between −25% and +25%, however lies typically around −10% in a wide range of the model parameters.