2005/05/27 by Tomas Brauner, Jiri Hosek
Physics and Astronomy · #hep-ph
paper · pdf · doi:10.1103/physrevd.72.045007
published as Phys.Rev. D72 (2005) 045007 · 9 pages, REVTeX4, uses feynmp, 1 eps figure
arxiv created 2005/05/27 · arxiv updated 2009/12/01
We consider a model with global Abelian chiral symmetry of two massless fermion fields interacting with a complex massive scalar field. We argue that the Schwinger-Dyson equations for the fermion and boson propagators admit ultraviolet-finite chiral-symmetry-breaking solutions provided the Yukawa couplings are large enough. The fermions acquire masses and the elementary excitations of the complex scalar field are the two real spin-zero particles with different masses. As a necessary consequence of the dynamical chiral symmetry breakdown both in the fermion and scalar sectors, one massless pseudoscalar Nambu--Goldstone boson appears in the spectrum as a collective excitation of both the fermion and the boson fields. Its effective couplings to the fermion and boson fields are calculable.