The fine-tuning of the generalised NMSSM

TL;DR

This paper evaluates the fine-tuning in a generalized NMSSM model with specific R-symmetry, finding it less severe than in MSSM/NMSSM and optimal near a 130 GeV Higgs mass.

Contribution

It introduces a generalized NMSSM with Z4 or Z8 R-symmetry and quantifies its reduced fine-tuning compared to traditional models.

Findings

Fine-tuning is significantly reduced in the generalized NMSSM.

Optimal fine-tuning occurs around a 130 GeV Higgs mass.

The model extends the acceptable Higgs mass range with less tuning.

Abstract

We determine the degree of fine-tuning needed in a generalised version of the NMSSM that follows from an underlying Z4 or Z8 R-symmetry. We find that it is significantly less than is found in the MSSM or NMSSM and extends the range of Higgs mass that have acceptable fine-tuning. Remarkably the minimal fine-tuning is achieved for Higgs masses of around 130 GeV.