## Higgs-Boson Masses and Mixing Matrices in the NMSSM: Analysis of On-Shell Calculations

Preprint number: CP3-Origins-2016-54 DNRF90
Authors: Peter Drechsel (DESY), Ramona Grober (IPPP Durham & INFN, Sezione di Roma Tre), Sven Heinemeyer (Universidad Autonoma de Madrid & Instituto de Fisica de Cantabria), Milada Muhlleitner (KIT), Heidi Rzehak (CP3-Origins), and Georg Weiglein (DESY)
We analyze the Higgs-boson masses and mixing matrices in the NMSSM based on an on-shell (OS) renormalization of the gauge-boson and Higgs-boson masses and the parameters of the top/scalar top sector. We compare the implementation of the OS calculations in the codes NMSSMCALC and NMSSM-FeynHiggs up to $\mathcal{({\alpha}_t{\alpha}_s)}$. We identify the sources of discrepancies at the one- and at the two-loop level. Finally we compare the OS and $\overline{\text{DR}}$ evaluation as implemented in NMSSMCALC. The results are important ingredients for an estimate of the theoretical precision of Higgs-boson mass calculations in the NMSSM.