Related papers: Multiscale Technicolor and the Zbb-bar Vertex
The origin of mass must lie in physics beyond the Standard Model. Dynamical electroweak symmetry breaking models like technicolor can generate masses for the W and Z bosons. Providing the large top quark mass and large top-bottom mass…
We consider a theory with composite top quarks but an elementary Higgs boson. The hierarchy problem can be solved by supplementing TeV scale top compositeness with either supersymmetry or Higgs compositeness appearing at the multi-TeV…
We study the decay mode of top quark decaying into Wb in the TC2 model where the top quark is distinguished from other fermions by participating in a strong interaction. We find that the TC2 correction to the decay width $\Gamma (t \to b W)…
In models of electroweak symmetry breaking in which the SM fermions get their masses by mixing with composite states, it is natural to expect the top quark to show properties of compositeness. We study the phenomenological viability of…
In the event that the Higgs mass is large or that the electroweak interactions are strongly interacting at high energy, top quark couplings to longitudinal components of the weak gauge bosons could offer important clues to the underlying…
We consider a model combining technicolor with the top quark condensation. As a concrete model for Technicolor we use the Minimal Walking Technicolor, and this will result in the appearance of a novel fourth generation whose leptons…
In the framework of topcolor-assisted technicolor(TC2) model, there exist tree-level flavor-changing (FC) couplings which can result in the loop-level FC coupling $tcg$. Such $tcg$ coupling can contribute significant clues at the…
The bottom quark forward-backward asymmetry ($A_{FB}^b$) data at LEP exhibits a long-standing discrepancy with the standard model prediction. We propose a novel method to probe the $Zb\bar{b}$ interactions through $gg\to Zh$ production at…
In usual extended technicolor (ETC) theories based on the group ${\rm{SU}(N_{ETC}})_{ETC}$, the quarks of charge 2/3 and -1/3 and the charged leptons of all generations arise from ETC fermion multiplets transforming according to the…
We consider extra dimensional descriptions of models where there are two separate strongly interacting sectors contributing to electroweak symmetry breaking (``topcolor'' type models). In the extra dimensional picture there would be two…
It is argued that the topcolor models recently proposed by Hill [1] may face significant constraints from flavor-changing neutral current processes (such as $B-\bar{B}$ mixing) unless the mixing angles between down-type quarks are small.…
The forward-backward asymmetry $A_{FB}$ in top quark pair production, measured at the Tevatron, is probably related to the contribution of new particles. The Tevatron result is more than a $2\sigma$ deviation from the standard model…
We perform a comprehensive study of the allowed range for the Tevatron t tbar forward-backward asymmetries in six representative new physics models: a flavour-changing Z' boson, a scalar isodoublet, a W' boson, a heavy axigluon, a…
In multiscale models of walking technicolor, relatively light color-singlet technipions are produced in $q \ol q$ annihilation in association with longitudinal $W$ and $Z$ bosons and with each other. The technipions decay as $\tpiz \ra b…
The measured forward-backward asymmetry in the t tbar production at the Tevatron might be explained by the additional exchange of a colored weak singlet scalar. Such state appears in some of the grand unified theories and its interactions…
We consider the top quark charge asymmetry in the process $pp \to t\bar{t}+\gamma$ at the 13 TeV LHC. The genuine tree level asymmetry in the $q\bar{q}$ channel is large with about -12%. However, the symmetric $gg$ channel, photon radiation…
We examine the effect of walking technicolor dynamics on the electroweak $S$ parameter and contrast it with the effect of QCD-like technicolor dynamics. Our main tools are the operator product expansion for the high-momentum behavior of the…
The interaction of bottom squark-mediated top quark pair production, occurring in the R-parity violating minimal supersymmetric standard model (MSSM), is proposed as an explanation of the anomalously large $t\bar{t}$ forward-backward…
Flavor changing effects on the processes \tch, \eebs, \eebsh and \ppbs in the LHT model are investigated in this paper. We calculate the one-loop level contributions from the T-parity odd mirror quarks and gauge bosons. The results show…
We extend our previous work on the precision electroweak tests in the Sp(6)_L X U(1)_Y family model to include for the first time the important Z->b b-bar vertex corrections encoded in a new variable epsilon_b, utilizing all the latest LEP…