Precise predictions for Higgs-masses in the Next-to-Minimal Supersymmetric Standard Model (NMSSM)

The NMSSM represents an elegant and well motivated description for the observed phenomenol-ogy in high energy physics. In this model a scalar singlet together with its superpartner is addedto the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM). In order to com-pare the NMSSM with experimental data at the same level of accuracy as the MSSM, precisepredictions for Higgs-boson masses in the NMSSM are a necessity. This work will focus on theprediction for the Higgs masses in the NMSSM at one- and two-loop order obtained by Feynmandiagrammatic methods. While the one-loop calculation is performed in the full NMSSM, thetwo-loop contributions to the Higgs-boson self-energies are approximated by their MSSM coun-terparts. It is shown that in this way the two-loop contributions are well approximated for a widerange of parameters. The results are exemplified for an example scenario genuine to the NMSSM