# SEMINAR

Vacuum stability in two Higgs doublet models

Dr. Pedro M. Ferreira

Tuesday, March 29th, 2005 at 04:00 PM

Abstract

In models with more than one Higgs field, there is the possibility of charged scalar fields acquiring a non-zero vaccuum expectation value, thus breaking the charge conservation symmetry, with disastrous results. Vaccua with spontaneous CP violation are also, in principe, possible through the same mechanism. We study the possibility of such minima developping at tree level in the most general two-Higgs dublet model. We discover that when a minimum that respects the gauge symmetry of the Standard Model exists, that minimum is the {\em global} one. We also discover the exact condition that has to be obeyed so that CP breaking minima can develop.