On the two-loop corrections to the Higgs masses in the NMSSM

TL;DR

This paper analyzes two-loop corrections to the Higgs mass in the NMSSM, showing their significant impact depending on singlet mass and coupling values, and highlighting limitations of MSSM-based approximations.

Contribution

It provides a comprehensive calculation of two-loop corrections in the NMSSM using SARAH and SPheno, including superpotential contributions beyond previous approximations.

Findings

Corrections reduce the Higgs mass by about 1 GeV for moderate λ with a heavy singlet.

For larger λ, corrections can increase the Higgs mass.

Light singlet scenarios show more significant and sometimes dominant corrections.

Abstract

We discuss the impact of the two-loop corrections to the Higgs mass in the NMSSM beyond $O(\alpha_S(\alpha_b + \alpha_t))$. For this purpose we use the combination of the public tools SARAH and SPheno to include all contributions stemming from superpotential parameters. We show that the corrections in the case of a heavy singlet are often MSSM-like and reduce the predicted mass of the SM-like state by about 1 GeV as long as $\lambda$ is moderately large. For larger values of $\lambda$ the additional corrections can increase the SM-like Higgs mass. If a light singlet is present the additional corrections become more important even for smaller values of $\lambda$ and can even dominate the ones involving the strong interaction. In this context we point out that important effects are not reproduced quantitatively when only including $O((\alpha_b+\alpha_t+\alpha_\tau)^2)$ corrections known from the MSSM.