Exploring viable vacua of the $Z_3$-symmetric NMSSM

TL;DR

This paper investigates the stability of vacua in the $Z_3$-symmetric NMSSM, considering quantum and thermal effects, and identifies parameter regions with stable or metastable symmetry-breaking vacua, relevant for collider phenomenology.

Contribution

It introduces a semi-analytical approach to study the NMSSM potential beyond tree level and compares it with existing tools, delineating stable and metastable vacua regions.

Findings

Stable and metastable vacua regions are mapped in the NMSSM parameter space.

Light singlet scalars and a singlino-like LSP are compatible with viable vacua.

Color and charge breaking minima are identified in certain parameter regions.

Abstract

We explore the vacua of the $Z_3$-symmetric Next-to-Minimal Supersymmetric Standard Model (NMSSM) and their stability by going beyond the simplistic paradigm that works with a tree-level neutral scalar potential and adheres to some specific flat directions in the field space. Key effects are demonstrated by first studying the profiles of this potential under various circumstances of physical interest via a semi-analytical approach. The results thereof are compared to the ones obtained from a dedicated package like \veva ~which further incorporates the thermal effects to the potential. Regions of the phenomenological NMSSM (pNMSSM) parameter space that render the desired symmetry breaking (DSB) vacuum absolutely stable, long- or short-lived (in relation to the age of the Universe) under quantum/thermal tunneling are delineated. Regions that result in color and charge breaking (CCB) minima are also presented. It is demonstrated that light singlet scalars along with a light LSP (lightest supersymmetric particle) having an appreciable singlino admixture are compatible with a viable DSB vacuum and are much relevant for the collider experiments.