Petr Beneš (Řež):
Dynamical breakdown of Abelian gauge chiral symmetry by strong Yukawa interactions
We consider a model with anomaly-free Abelian gauge
axial-vector symmetry, which is intended to mimic the standard electroweak gauge
chiral SU(2)L x U(1)Y theory. Within this model we demonstrate:
(1) Strong Yukawa interactions
between massless fermion fields and a massive scalar field carrying the axial charge generate dynamically
the fermion and boson proper self-energies, which are ultraviolet-finite and chirally noninvariant.
(2) Solutions of the underlying Schwinger-Dyson equations found numerically exhibit a huge amplification
of the fermion mass ratios as a response to mild changes of the ratios of the Yukawa couplings.
(3) The `would-be' Nambu-Goldstone boson is a composite of both the fermion and scalar fields, and it
gives rise to the mass of the axial-vector gauge boson. (4) Spontaneous breakdown of the gauge
symmetry further manifests by mass splitting of the complex scalar and by new symmetry-breaking
vertices, generated at one loop. In particular, we work out in detail the cubic vertex of the Abelian
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