Dynamically induced spontaneous symmetry breaking in 3–3–1 models

We show that in SU(3)C⊗SU(3)L⊗U(1)N (3–3–1) models embedded with a singlet scalar playing the role of the axion, after imposing scale invariance, the breaking of Peccei–Quinn symmetry occurs through the one-loop effective potential for the singlet field. We, then, analyze the structure of spontaneous symmetry breaking by studying the new scalar potential for the model, and verify that electroweak symmetry breaking is tightly connected to the 3–3–1 breaking by the strong constraints among their vacuum expectation values. This offers a valuable guide to write down the correct pattern of symmetry breaking for multi-scalar theories. We also obtained that the accompanying massive pseudo-scalar, instead of acquiring mass of order of Peccei–Quinn scale as we would expect, develops a mass at a much lower scale, a consequence solely of the breaking via Coleman–Weinberg mechanism.