Strong first-order phase transitions in the NMSSM --- a comprehensive survey

TL;DR

This paper provides a comprehensive survey of the phase structure in the NMSSM, identifying conditions for strong first-order phase transitions that could explain baryogenesis and produce observable gravitational waves.

Contribution

It systematically classifies phase transition patterns in the NMSSM and identifies parameter regions with strong first-order transitions, including detailed benchmark analyses.

Findings

Rich phase transition patterns ending in electroweak symmetry breaking

Identification of parameter regions with strong first-order phase transitions

Samples showing potential for baryogenesis and gravitational wave signals

Abstract

Motivated by the fact that the Next-to-Minimal Supersymmetric Standard Model is one of the most plausible models that can accommodate electroweak baryogenesis, we analyze its phase structure by tracing the temperature dependence of the minima of the effective potential. Our results reveal rich patterns of phase structure that end in the observed electroweak symmetry breaking vacuum. We classify these patterns according to the first transition in their history and show the strong first-order phase transitions that may be possible in each type of pattern. These could allow for the generation of the matter-antimatter asymmetry or potentially observable gravitational waves. For a selection of benchmark points, we checked that the phase transitions completed and calculated the nucleation temperatures. We furthermore present samples that feature strong first-order phase transitions from an extensive scan of the whole parameter space. We highlight common features of our samples, including the fact that the Standard Model like Higgs is often not the lightest Higgs in the model.