Decay widths of the neutral $\mathcal{CP}$-even MSSM Higgs bosons in the Feynman-diagrammatic approach

Abstract.

In the Minimal Supersymmetric Standard Model (MSSM) we incorporate the Higgs-boson propagator corrections, evaluated up to two-loop order, into the prediction of $\Gamma(h \to f\bar f)$ and $BR(h \to f \bar f)$ for $f = b, c, \tau$. The propagator corrections consist of the full one-loop contribution, including the effects of non-vanishing external momentum, and corrections of $\mathcal{O}(\alpha\alpha_s)$ at the two-loop level. The results are supplemented with the dominant one-loop QED corrections and final state QCD corrections from both gluons and gluinos. The effects of the two-loop propagator corrections and of the one-loop gluino contributions are investigated in detail. Our results are compared with the result obtained within the renormalization group approach. Agreement within 10% is found for most parts of the MSSM parameter space.