Top-quark condensation

Abstract

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)

Probing new physics from top-charm associated productions at Linear Colliders

“…In the TC2 model the strong top-color gauge interaction causes the top-quark to condensate, which leads to the presence of top-pions. The compositeness scale of top-pions is about the mass scale of top-color gauge boson, which is usually assumed to be a few TeV [2,4]. So at the ILC energy (a few hundred GeV to 1 TeV), the top-pions can be regarded as point-like particles.…”

“…Among various kinds of dynamical electroweak symmetry breaking models, the TC2 model [2][3][4] is especially attractive since it connects the top quark with the electroweak symmetry breaking (EWSB). In this model, the topcolor interactions make small contributions to the EWSB, but give rise to the main part of the top quark mass (1 − ǫ)m t with a model dependent parameter ǫ.…”

“…Theoretical studies show that the top quark processes are sensitive to new physics [1]. In some new physics models like the popular Minimal Supersymmetric Model (MSSM) and the topcolor-assisted technicolor (TC2) model [2][3][4], the top quark may have some exotic production and decay channels [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Among these exotic processes, one kind is induced by the flavor-changing neutral-current (FCNC) interactions, which are extremely suppressed in the SM but could be significantly enhanced in some extensions [7][8][9][10][11][12][13][14][15][16][17][18].…”

An effective strong-coupling theory of composite particles in UV-domain

“…In 1989, several authors [28][29][30][31][32][33] suggested that the SM symmetry breakdown could be a dynamical mechanism of the NJL type that intimately involves the top quark at the high-energy scale Λ. Since then, many models based on this idea have been studied [34,35]. In the scenes of renormalization group (scaling) invariance and resultant renormalization-group (RG) equations, there is a scaling region (IR-domain) of the infrared (IR) stable fixed point of four-fermion operators, the low-energy SM physics was supposed to be achieved by the RG equations in the IR-domain with the electroweak scale v ≈ 239.5 GeV [25][26][27][28]33].…”

Precise photoproduction of the charged top-pions at the LHC with forward detector acceptances

“…The parameter sin ω indicates the fraction of EWSB provided by the top condensate. The top-pion mass M π t depends on the amount of top-quark mass arising from the extended technicolor (ETC) sector and on the effects of EW gauge interactions [55,56], and thus its value is model-dependent. In the context of the TTM model, Ref.…”