Neutral Higgs boson production at e⁺ e⁻ colliders in the complex MSSM: a full one-loop analysis

For the search for additional Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM) as well as for future precision analyses in the Higgs sector precise knowledge of their production properties is mandatory. We evaluate the cross sections for the neutral Higgs boson production at e⁺ e⁻ colliders in the MSSM with complex parameters (cMSSM). The evaluation is based on a full one-loop calculation of the production mechanism e⁺ e⁻ → hiZ, hiγ, hihj (i,j =1,2,3), including soft and hard QED radiation. The dependence of the Higgs boson production cross sections on the relevant cMSSM parameters is analyzed numerically. We find sizable contributions to many cross sections. They are, depending on the production channel, roughly of 10-20 % of the tree-level results, but can go up to 50 % or higher. The full one-loop contributions are important for a future linear e⁺ e⁻ collider such as the ILC or CLIC. There are plans to implement the evaluation of the Higgs boson production cross sections into the code FeynHiggs.