New vacuum stability limit from cosmological history

TL;DR

This paper explores how the early universe's cosmological history influences the stability of the electroweak vacuum, especially considering new physics models that could introduce deeper vacuum states, and proposes a method to efficiently determine stability limits.

Contribution

It provides a detailed analysis of vacuum stability constraints in the singlet extension of the Standard Model and discusses implications for supersymmetry, introducing an efficient calculation procedure.

Findings

Constraints on model parameters from vacuum stability.

Potential for the universe to be trapped in a non-electroweak vacuum.

A new method for calculating stability limits efficiently.

Abstract

The stability of the electroweak vacuum imposes important constraints on new physics models. Such new physics models may introduce one or more new thermal phases with a lower free energy than that of the electroweak vacuum. In this case, the early universe may stay or have already evolved into one of these deeper vacuum states. We investigate this possibility in detail in the singlet extension of the Standard Model, and delineate the corresponding constraints in its parameter space. We also discuss the situation in supersymmetry as another example. To account for the possibility that the universe is trapped in a non-electroweak vacuum, we propose a procedure of calculating the vacuum stability limit efficiently.