English

Phase Structure of the Gauged Yukawa Model

High Energy Physics - Phenomenology 2011-01-13 v1 High Energy Physics - Lattice

Abstract

Based on the ladder Schwinger-Dyson equation, we investigate phase struc- ture of the gauged Yukawa model possessing a global SU(2)L×SU(2)RSU(2)_L \times SU(2)_R symmetry and an unbroken (vector-like) gauge symmetry. We show that even when we tune the squared mass of the scalar boson in the Lagrangian to be positive, there still exists the dynamical chiral symmetry breaking due to fermion pair condensate (VEV of the composite scalar) triggered by the strong Yukawa coupling larger than a certain critical value. We find a "nontrivial ultraviolet fixed line" and "renormalized trajectories" in the three-dimensional coupling space of the Yukawa coupling, the gauge cou- pling and the "hopping parameter" of the elementary scalar field. Presence of the gauge coupling is crucial to existence of the fixed line. Implications of the result for the lattice calculation and the top quark condensate model are also discussed.

Keywords

Cite

@article{arxiv.hep-ph/9312322,
  title  = {Phase Structure of the Gauged Yukawa Model},
  author = {Kei-ichi Kondo and Akihiro Shibata and Masaharu Tanabashi and Koichi Yamawaki},
  journal= {arXiv preprint arXiv:hep-ph/9312322},
  year   = {2011}
}

Comments

in LaTeX 44 pages +15 figures (figures are tared compressed uuencoded postscript file ;separated 3 parts), DPNU-93-45, CHIBA-EP-73, KEK-TH-380 and KEK Preprint 93-171