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

摘要

The scalar potential of the two-Higgs-doublet model 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 two-Higgs- doublet model and obtain new constraints which could be important in phenomenological studies.