On MSSM charged Higgs-boson production in association with an electroweak W boson at electron–positron colliders

We present a calculation of the cross section for the process e⁺e^-→W^±H^∓ in the minimal supersymmetric standard model (MSSM) and the two Higgs doublet model (THDM). We study the basic features of the MSSM prediction for some distinctive parameter scenarios. We find large effects from virtual third-generation squarks for scenarios with large mixing, which can lead to a cross section vastly different from a THDM with identical Higgs sector parameters. We investigate this interesting behaviour in more detail by thoroughly scanning the MSSM parameter space for regions of large cross section. For a charged Higgs boson too heavy to be pair produced at a future high-energy electron–positron collider it turns out that a large MSSM cross section with a good chance of observation is linked to a squark mass scale below 600 GeV and a considerable amount of mixing in either the stop and sbottom sector.