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 Λ a top quark condensate H=〈t-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 nontrivial minimum in the effective potential leads to the condition that the cutoff Λ is limited from above, (formula presented)), and to a new lower bound for the four-fermion coupling a=((formula presented))/(8(formula presented))1.60. Similar results are obtained if we demand, instead, that the next-to-leading order contributions do not shift the location z=((formula presented) 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/(formula presented) expansion are included. Dominant QCD effects are also included, but their impact on the numerical results is shown to be small. © 1996 The American Physical Society.
|Number of pages||19|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|Publication status||Published - 1 Jan 1996|
Cvetič, G., Paschos, E. A., & Vlachos, N. D. (1996). Condensation effects beyond one loop in the top-mode standard model without gauge bosons. Physical Review D - Particles, Fields, Gravitation and Cosmology, 2820-2838. https://doi.org/10.1103/PhysRevD.53.2820