# Tree-level vacuum stability of two-Higgs-doublet models and new constraints on the scalar potential

## TL;DR

This paper investigates the conditions under which the vacuum in two-Higgs-doublet models is stable at tree-level, providing new constraints on the scalar potential that are relevant for phenomenological analyses.

## Contribution

It derives conditions ensuring the considered vacuum is the global minimum in 2HDMs, adding new theoretical constraints to stabilize the scalar potential.

## Key findings

- Derived tree-level vacuum stability conditions for 2HDMs
- Identified new constraints on the scalar potential parameters
- Applied constraints to a specific 2HDM model

## Abstract

The scalar potential of the two-Higgs-doublet model (2HDM) may have more than one local minimum and the usually considered vacuum could be located at one of them that could decay to another. This paper studies the condition that the usually considered vacuum is the global minimum which, combined with the bounded-from-below condition, will stabilize the vacuum at tree-level. We further apply these conditions to a specific 2HDM and obtain new constraints which could be important in phenomenological studies.