Evading death by vacuum

TL;DR

This paper explores the vacuum stability in two-Higgs-doublet models, showing that current LHC data already exclude the existence of dangerous metastable 'panic vacuums' in these theories.

Contribution

It demonstrates that in a specific two-Higgs-doublet model with a softly broken U(1) symmetry, the LHC results rule out the possibility of metastable panic vacuums.

Findings

LHC data constrains two-Higgs-doublet models

Panic vacuum solutions are precluded in the studied model

Current experiments limit vacuum metastability

Abstract

In the Standard Model, the Higgs potential allows only one minimum at tree-level. But the open possibility that there might be two scalar doublets enriches the vacuum structure, allowing for the risk that we might now be in a metastable state, which we dub the panic vacuum. Current experiments at the LHC are probing the Higgs particle predicted as a result of the spontaneous symmetry breaking. Remarkably, in the two Higgs model with a softly broken U(1) symmetry, the LHC experiments already preclude panic vacuum solutions.