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

Understand

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.