Related papers: Top Quark Compositeness: Feasibility and Implicati…
Composite Higgs models provide a natural, non-supersymmetric solution to the hierarchy problem. In these models, one or more sets of heavy top-partners are typically introduced. Some of these new quarks can be relatively light, with a mass…
In this talk we review the physics of top-quark mass generation in models of dynamical electroweak symmetry breaking and the constraints on this physics arising from limits on the deviation of the weak interaction $\rho$-parameter from one.…
We review recent measurements of the properties of the top quark: the decay width of the top quark, of spin correlations between the top and the antitop quarks in $\ttbar$ production, the $W$ boson helicity in top decays, the strong colour…
The latest results on top quark physics, namely single top quark production cross sections, $W$-boson helicity and asymmetry measurements are used to probe the Lorentz structure of the $Wtb$ vertex. The increase of sensitivity to new…
Composite particles generated by an unknown strong dynamics can be responsible for the ElectroWeak Symmetry Breaking (EWSB) and can substitute the Standard Model (SM) Higgs boson in keeping perturbative unitarity in the longitudinal WW…
Recent calculations are presented of top quark polarization in $t\bar t$ pair production close to threshold. S-P-wave interference gives contributions to all components of the top quark polarization vector. Rescattering of the decay…
After the discovery of the top quark more than 20 years ago, top quark production cross sections have been meticulously studied. The rich variety of results from the LHC experiments are complemented with increasingly accurate theoretical…
We consider the constraints that critical dynamics places on models with a top quark condensate or strong extended technicolor (ETC). These models require that chiral-symmetry-breaking dynamics at a high energy scale plays a significant…
In this contribution to the 2021 Snowmass community planning exercise that informs the American strategy for particle physics, we present the prospects for measurements of the top-quark couplings at future colliders. Projections are…
We describe a realistic, renormalizable, supersymmetric ``quindecuplet'' model in which the top quark, left handed bottom quark, and up-type Higgs boson are composite, with a compositeness scale $\sim 1-3$ TeV. The top-Higgs Yukawa coupling…
Fermion masses may arise via mixing of elementary fermions with composite fermions of a strong sector in scenarios of strongly-coupled electroweak symmetry breaking. The strong sector may contain leptoquark states with masses as light as…
We study symmetry breaking in a left-right symmetric extension of the Standard Model with mirror fermions, one for each Standard-Model fermion. The new particles assist a top-quark condensate in breaking electro-weak symmetry. Half of the…
Measurements of the top quark by the ATLAS and CMS experiments go beyond testing the Standard Model (SM) with high precision. Axion-like particles (ALPs), a potential SM extension involving new pseudoscalar particles, exhibit strong…
Since its discovery in 1995 by the CDF and D0 collaborations at the Fermilab Tevatron collider, the top quark has undergone intensive studies. Besides the Tevatron experiments, with the start of the LHC in 2010 a top quark factory started…
The LHC will be a top-quark factory. With 80 million pairs of top quarks and an additional 34 million single tops produced annually at the designed high luminosity, the properties of this particle will be studied to a great accuracy. The…
We propose a new mechanism in which all of the electroweak symmetry breaking is driven by a natural top quark condensate, produced by topcolor interactions at a multi-TeV scale. The scheme allows the observed top quark mass, and acceptable…
It has been recently argued that realistic models with warped extra dimensions can have Kaluza-Klein particles accessible at the Large Hadron Collider if a custodial symmetry, SU(2)_V \times P_{LR}, is used to protect the T parameter and…
The role of the top quark in completing the Standard Model quark sector is reviewed, along with a discussion of production, decay, and theoretical restrictions on the top quark properties. Particular attention is paid to the top quark as a…
Right-handed light quarks could be significantly composite, yet compatible with experimental searches at the LHC and precision tests on Standard Model couplings. In these scenarios, that are motivated by flavor physics, one expects large…
We study the sensitivity reach to probe the electroweak dipole operators associated with a top quark at a multi-TeV lepton collider. Studying the electroweak dipole operators is strongly motivated by precision physics. The operators exhibit…