Condensation effects beyond one loop in the Top-mode Standard Model without gauge bosons

Abstract

We study dynamical symmetry breaking in the Standard Model including the next-to-leading order terms. We introduce at a high, but finite, energy scale Lambda a top quark condensate H={t {bar t}} and derive, using path integral methods, the effective potential including quadratic fluctuations in the scalar field H. We neglect the contributions of all components of the massive electroweak gauge bosons. The existence of a non-trivial minimum in the effective potential leads to the condition that the cut-off Lambda is limited from above: Lambda < Lambda_{crit} approx 4.7 m_t^{phys.} (for N_c = 3), and to a new lower bound for the 4-fermion coupling a = (G N_c Lambda^2)/(8 pi^2) > 1.60. Similar results are obtained if we demand, instead, that the next-to-leading order contributions not shift the location z=(m_t^{bare}/Lambda)^2 of the minimum drastically, e.g.~by not more than a factor of 2. The results are reproduced diagrammatically, where the leading plus all the next-to-leading order diagrams in the (1/N_c)-expansion are included. Dominant QCD effects are also included, but their impact on the numerical results is shown to be small.

30 pages, LaTeX, 9 figures included in a separate tar-compressed and uuencoded PostScript file; QCD effects included, formulations improved, new figures 1a-1e

References in corpus (4)

• Evidence for Top Quark Production in $\bar{p}p$ Collisions at $\sqrt{s}=1.8$ TeV
• Regularization in the Gauged Nambu--Jona-Lasinio Model
• Study of ttbar Production in ppbar Collisions Using Total Transverse Energy
• Exact Cancellation of Quadratic Divergences in Top Condensation Models

Cited by in corpus (12)

• Top quark condensation
• The Nambu sum rule and the relation between the masses of composite Higgs bosons
• Regularization at the next-to-leading order in the top-mode standard model without gauge bosons
• Scalar excitation with Leggett frequency in ${}^3$ He-B and the $125$ GeV Higgs particle in top quark condensation models as Pseudo - Goldstone bosons
• Gauge theory of Lorentz group as a source of the dynamical electroweak symmetry breaking
• A Top Quark Soliton and its Anomalous Chromomagnetic Moment
• Strong dynamics behind the formation of the $125$ GeV Higgs boson
• Goldstone modes and the Higgs condensation beyond one loop
• Spontaneous CP Symmetry Breaking at the Electroweak Scale
• Schwinger - Dyson equation and NJL approximation in massive gauge theory with fermions
• Modified model of top quark condensation
• Modified top quark condensation model with the extra heavy fermion, the $125$ GeV Pseudo - Goldstone boson, and the additional heavy scalar bosons