Related papers: Light 't Hooft Top Partners
A scenario is presented where the $s$, $c$, and $b$ quark fusion Higgs production cross sections are enhanced with respect to those of the Standard Model. In particular the $c$ quark fusion production is very important and can account for a…
The new vector-like top partners with charge $2/3$ are a typical feature of many new physics models beyond the Standard Model (SM). We propose a search strategy for single production of top partners $T$ focusing on both the $T\to Wb$ and…
We consider an extension of the MSSM with an added vectorlike top partner. Our aim is to revisit to what extent such an extension can raise the Higgs boson mass through radiative corrections and help ameliorate the MSSM hierarchy problem,…
First observed in 1995, the top quark is one of a pair of third-generation quarks in the Standard Model of particle physics. It has charge +2/3e and a mass of 171.4 GeV, about 40 times heavier than its partner, the bottom quark. The CDF and…
Pair production of new vector-like quarks in $pp$ collisions is considered model independent as it is usually dominated by QCD production. Nonetheless, the presence of a new massive color octet (heavy gluon) in some composite Higgs models…
Standard-model fields and their associated electroweak Lagrangian are equivalently expressed in a shared spin basis. The scalar-vector terms are written with scalar-operator components acting on quark-doublet elements, and shown to be…
As the heaviest known fundamental particle, the top quark has taken a central role in the study of fundamental interactions. The top quark mass is a fundamental parameter of the standard model which places constraints on the Higgs boson…
The composite subquark model previously proposed by us shows that the intermediate $Z^{0}$-weak-boson is realized as the composite particle and that its scalar partner has the mass value larger than $Z^{0}$-weak-boson mass. It is suggested…
This letter presents a search for singly produced vector-like quarks, Q, coupling to light quarks, q. The search is sensitive to both charged current (CC) and neutral current (NC) processes, p p --> Q q --> W q q' and p p --> Q q --> Z q q'…
Many standard model extensions that address the hierarchy problem contain Dirac-fermion partners of the top quark, which are typically expected around the TeV scale. Searches for these vector-like quarks mostly focus on their decay into…
We analyze the correlation function of a meson with one heavy and one light quark in inverse powers of the heavy quark mass $m_Q$ using a succession of Foldy-Wouthuysen-type transformations prior to radiative corrections. We evaluate the…
We reexamine a possibility for the existence of a light supersymmetric partner of the top quark (stop) with mass 15$\sim$16GeV in the framework of the minimal supergravity GUT model (MSGUT). Such a stop could explain the slight excess of…
The results of a search for pair production of the lighter scalar partners of top quarks in 2.05 fb-1 of pp collisions at sqrt(s) =7 TeV using the ATLAS experiment at the LHC are reported. Scalar top quarks are searched for in events with…
Starting from the historical Fermi four-fermion low-energy effective electroweak interactions Lagrangian for the third generation of quarks, augmented by an NJL type interaction responsible for dynamical symmetry breaking and heavy quark…
The minimal model of spontaneously broken leptonic colour and discrete quark-lepton symmetry predicts that charged leptons have the same masses as their partner charge $+2/3$ quarks up to small radiative corrections. By invoking a different…
Relatively light Top Partners are unmistakable signatures of reasonably Natural Composite Higgs models and as such they are worth searching for at the LHC. Their phenomenology is characterized by a certain amount of model-dependence, which…
Light top partners are the prime sign of naturalness in composite Higgs models. We explore here the possibility of non-standard top partner phenomenology. We show that even in the simplest extension of the minimal composite Higgs model,…
We show that if the Standard Model gauge fields and fermions propagate in extra dimenions, a composite Higgs field with the correct quantum number can arise naturally as a bound state due to the strong gauge interactions in higher…
Grand-unified models with extra dimensions at the GUT scale will typically contain exotic states with Standard Model charges and GUT-scale masses. They can act as messengers for gauge-mediated supersymmetry breaking. If the number of…
A composite Higgs boson is likely to be accompanied by additional light states generated by the same dynamics. This expectation is substantiated when realising the composite Higgs mechanism by an underlying gauge theory. We review the…