2004/05/03 by G. Sartori, Sartori, G., G. Valente +1
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Particle physics theoretical and experimental studies #hep-th
paper · pdf · doi:10.48550/arxiv.hep-th/0405021
49 pages, 16 figures, 14 tables; typeset in LaTeX, JHEP style
arxiv created 2004/05/03 · openalex publication_date 2004/05/03 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In Quantum Field Theory models with spontaneously broken gauge invariance, renormalizability limits to four the degree of the Higgs potential, whose minima determine the vacuum state at tree-level. In many models, this bound has the intriguing consequence of preventing the observability, at tree-level, of some phases that would be allowed by symmetry. We show that, generally, the phenomenon persists also if one-loop radiative corrections are taken into account. The tree-level unobservability of some phases is characteristic in two-Higgs-doublet extensions of the Standard Model with additional discrete symmetries (to protect against neutral current flavor changing effects, for instance). We show that an extension of the scalar sector through suitable singlet fields can resolve the \em unnatural limitations on the observability of all the phases allowed by symmetry.