Koniuk, R.Tarrach, R., 1948-2010-05-062010-05-0619850556-2821https://hdl.handle.net/2445/12434We study the existence of a stable ground state for the most general renormalizable single scalar field theory in four dimensions within a variational approach. In its regularized version we find a theory with an energy density which is not bound from below but with a metastable local minimum such that when the cutoff is removed the theory is interacting, finite, and possesses a stable ground state. In fact, we find that this theory is not stable unless it is symmetric. This generalizes Stevenson’s recent results on even φ 4 theory.5 p.application/pdfeng(c) The American Physical Society, 1985Teoria quànticaTeoria de camps (Física)Partícules (Física nuclear)Relativitat especial (Física)Quantum theoryField theory (Physics)Particles (Nuclear physics)Special relativity (Physics)info:eu-repo/semantics/article14189info:eu-repo/semantics/openAccess