Variation of the cross section for e⁺e^- → W ⁺H^- in the minimal supersymmetric standard model

We study the loop-induced process e⁺e^- → W ⁺H^- in the minimal supersymmetric standard model (MSSM). This process allows the charged Higgs boson to be produced in e ⁺e^- collisions when e⁺e^- → H⁺H^- is kinematically forbidden due to a large charged Higgs boson mass. We scan over the MSSM parameters subject to experimental constraints to examine the range of values the cross section can take. We find that large enhancements of the cross section over that in a nonsupersymmetric two Higgs doublet model are possible, especially for large tan β and light top and bottom squarks. Choosing a few typical MSSM parameter sets, we show the regions in the m_H±-tan β plane in which at least 10 W^±H^∓ events would be produced at the e ⁺e^- collider.