Higgs decays into charginos and neutralinos 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 a precise knowledge of their decay properties is mandatory. We evaluate all two-body decay modes of the Higgs bosons into charginos and neutralinos in the MSSM with complex parameters (cMSSM). The evaluation is based on a full one-loop calculation of all decay channels, also including hard QED radiation. We restricted ourselves to a version of our renormalization scheme which is valid for $$|M_1| < |M_2|, |\mu |$$ and $$M_2 \ne \mu $$ to simplify the analysis, even though we are able to switch to other parameter regions. The dependence of the Higgs boson predictions on the relevant cMSSM parameters is analyzed numerically. We find sizable contributions to many partial decay widths. They are roughly of 10 % of the tree-level results, but they can go up to 20 % or higher. The full one-loop contributions are important for the correct interpretation of heavy Higgs boson search results at the LHC and, if kinematically allowed, at a future linear $$e^+e^-$$ collider. There are plans to implement the evaluation of the branching ratios of the Higgs bosons into the Fortran code FeynHiggs, together with an automated choice of the renormalization scheme valid for the full cMSSM parameter space