Vacuum stability in models with extended Higgs sectors

Determining the stability of the Electroweak Vacuum in extensions of the Standard Model is a non-trivial problem already at tree level, for, in renormalizable theories, it requiresknowing the full structure of all extrema of a quartic polynomial in a possibly high-dimensional field space. Going beyond lowest order requires adding logarithmic corrections that make the problem numerically more challenging. We study this question within the context of the NMSSM using VeVacious, a tool that performs numerical minimization of the 1-loop effective potential around the tree-level extrema. In particular, we focus on classifying the glogal minimum structure in the light singlet region considered by Pokorski et al., which can have interesting experimental signatures.