Chiral hierarchies, compositeness, and the renormalization group

Bardeen, William A.; Hill, Christopher T.; Jungnickel, D.-U.

doi:10.1103/physrevd.49.1437

Cited by 23 publications

(44 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This theory has been investigated in much detail recently in [16][17][18][19][20] for a large number of interesting properties, not directly connected with compositeness. It has been studied earlier in connection with top-quark condensate models in [22,23], albeit in a different setup and limit that we here are taking.…”

Section: The Composite Templatementioning

confidence: 99%

See 1 more Smart Citation

Four-fermion limit of gauge-Yukawa theories

2015

View full text Add to dashboard Cite

We elucidate and extend the conditions that map gauge-Yukawa theories at low energies into time-honoured gauged four-fermion interactions at high energies. These compositeness conditions permit to investigate theories of composite dynamics through gauge-Yukawa theories. Here we investigate whether perturbative gauge-Yukawa theories can have a strongly coupled limit at high-energy, that can be mapped into a four-fermion theory. Interestingly, we are able to precisely carve out a region of the perturbative parameter space supporting such a composite limit. This has interesting implications on our current view on models of particle physics. As a template model we use an SU(N C ) gauge theory with N F Dirac fermions transforming according to the fundamental representation of the gauge group. The fermions further interact with a gauge singlet complex N F × N F Higgs that ceases to be a physical degree of freedom at the ultraviolet composite scale, where it gives away to the four-fermion interactions. We compute the hierarchy between the ultraviolet and infrared composite scales of the theory and show that they are naturally large and well separated. Our results show that some weakly coupled gauge-Yukawa theories can be viewed, in fact, as composite theories. It is therefore tantalising to speculate that the standard model, with its phenomenological perturbative Higgs sector, could hide, in plain sight, a composite theory.

show abstract

Section: The Composite Templatementioning

confidence: 99%

“…We further require the sign of m 2 H to be positive to match the ultraviolet gNJL theory and to ensure stability of the scalar vacuum at the origin (for the Coleman-Weinberg instabilities concerning the case m 2 H = 0 see [23]). The compositeness conditions tell us that the mass parameter must also diverge at the composite scale.…”

Section: Composite Limitmentioning

confidence: 99%

Four-fermion limit of gauge-Yukawa theories

2015

View full text Add to dashboard Cite

show abstract

“…Since coupling parameters at ⌳ are large, several authors have performed calculations in the model (with N f ϭ2, N c ϭ3) aimed at improving the (one-loop) perturbative approach of Chivukula, Golden, and Simmons, primarily by employing various nonperturbative approximations in the energy region ϳ⌳ (Shen, 1993;Bardeen, Hill, and Jungnickel, 1994;Clark and Love, 1995;Khlebnikov and Schnathorst, 1995). calculated in the NJLVL U(2) L ϫU(2) R framework (9.2) the explicit leading-N c solution.…”

Section: B Some Theoretical Issues and Questions About T¯t Condensatmentioning

confidence: 99%

Top-quark condensation

1999

View full text Add to dashboard Cite

Top-quark condensation, in particular the minimal framework in which the neutral Higgs scalar is (predominantly) an effective tt condensate of the standard model, is reviewed. Computational approaches are compared and similarities, differences, and deficiencies pointed out. Extensions of the minimal framework, including scenarios with two composite Higgs doublets, additional neutrino condensates, and tt condensation arising from four-fermion interactions with enlarged symmetries, are described. Possible renormalizable models of underlying physics potentially responsible for the condensation, including topcolor-assisted technicolor frameworks, are discussed. Phenomenological implications of top condensate models are outlined. Outstanding theoretical issues and problems for future investigation are pointed out. Progress in the field after this article was accepted has been briefly covered in a Note added at the end. [S0034-6861(99)

show abstract

“…It is of note that at next-to-leading order in N there are contributions which may make the phase transition weakly first order[23,24] due to the Coleman-Weinberg mechanism[25] 3. This can be seen in eqn.…”

mentioning

confidence: 98%

Large-Nand vacuum alignment in top-color models

Chivukula

1998

Phys. Rev. D

View full text Add to dashboard Cite

Topcolor and topcolor-assisted technicolor provide examples of dynamical electroweak symmetry breaking which include top-condensation, thereby naturally incorporating a heavy top quark. In this note we discuss the roles of the Nambu-Jona-Lasinio (NJL) and large-N approximations often used in phenomenological analyses of these models. We show that, in order to provide for top-condensation but not bottom-condensation, the top-color coupling must be adjusted to equal the critical value for chiral symmetry breaking up to O(1/N ) in any theory in which the isospin-violating "tilting" interaction is a U (1) gauge interaction. A consequence of these considerations is that the potentially dangerous "bottom-pions" are naturally light. We also show that the contributions to ρ − 1 previously estimated are of leading-order in N , are not included in the usual NJL analysis, and are the result of "vacuum-alignment".

show abstract

Chiral hierarchies, compositeness, and the renormalization group

Cited by 23 publications

References 25 publications

Four-fermion limit of gauge-Yukawa theories

Four-fermion limit of gauge-Yukawa theories

Top-quark condensation

Large-Nand vacuum alignment in top-color models

Contact Info

Product

Resources

About