# The Singlet Extended Standard Model in the Context of Split Supersymmetry

## TL;DR

This paper investigates a singlet-extended Standard Model derived from split supersymmetry, comparing two methods of calculating the scalar mass spectrum and highlighting the limited parameter space compatibility with full SUSY models.

## Contribution

It provides a detailed comparison of scalar mass calculations in the singlet-extended Standard Model using two different approaches, revealing significant deviations and limitations in simplified models.

## Key findings

- Significant differences between the two mass calculation methods.
- Limited parameter space compatibility with full supersymmetric models.
- Properties of additional fermions can differ substantially.

## Abstract

We consider a low-energy effective theory of the next-to-minimal supersymmetric Standard Model by decoupling all scalar states except one Higgs doublet and the complex gauge singlet. The mass spectrum of the resulting singlet-extended Standard Model is calculated from two different perspectives: 1) using a matching of the scalar sectors at next-to-leading order; 2) using the simplified-model approach of calculating the masses in the effective theory at fixed order at the weak scale ignoring any connection to the full theory. Significant deviations between the two methods are found not only in the scalar sector, but also properties of the additional fermions can be very different. Thus, only a small part of the parameter space of the simplified model can be embedded in a well motivated SUSY framework.