Related papers: Top-quark Partial Compositeness beyond the effecti…
As the heaviest known fundamental particle, the top quark has taken a central role in the study of fundamental interactions. Production of top quarks in pairs provides an important probe of strong interactions. The top quark mass is a key…
We are looking for remarkable differences between predictions of the standard model and those of $t_R$ compositeness (while the $t_L$ remains elementary) in various basic $t\bar t$ production processes, without having to make difficult…
We study the phenomenology of a strongly-interacting top quark at future hadron and lepton colliders, showing that the characteristic four-top contact operators give rise to the most significant effects. We demonstrate the extraordinary…
Overview on top couplings measurements is presented, and the prospects of future measurements are discussed. The coupling of top to the W boson can be examined either by looking at the decay of the top quark or from single top quark…
The top quark is the heaviest elementary particle observed to date. Its large mass makes the top quark an ideal laboratory to test predictions of perturbation theory concerning heavy quark production at hadron colliders. The top quark is…
Top-quark physics plays an important role at hadron colliders such as the Tevatron collider at Fermilab or the upcoming Large Hadron Collider (LHC) at CERN. Given the planned experimental precision, detailed theoretical predictions are…
The fundamental Higgs doublet may be replaced in the Standard Model by certain non-perturbative four-quark interactions, whose effect is to induce a composite Higgs sector responsible for electroweak symmetry breaking. A simple composite…
We review the model-independent description of the couplings of the top quark to the Higgs and gauge bosons in theories beyond the Standard Model. Then we examine these couplings in the case of arbitrary heavy vector-like quarks mixing with…
Starting from the Fock space representation of hadron bound states in a quark model, a change of representation is implemented by a unitary transformation such that the composite hadrons are redescribed by elementary-particle field…
Motivated by recently observed anomalies in the flavour sector, we analyse the potential of measurements of top quarks at the Large Hadron Collider (LHC) to provide complementary constraints on interactions that shape low-energy precision…
We extend our previous analysis of $t\bar t H, t\bar t Z, t\bar b W$ production in $e^+e^-$ collisions within the CSM (Composite Standard Model) concept of Higgs boson and top quark compositeness to the case of gluon-gluon and photon-photon…
The Tevatron, where the top quark was discovered, and the currently functional Large Hadron Collider (LHC), with copiously produced top pairs, enable a detailed study of top-quark properties. In particular, they can be used to test the…
Recent measurements at the Large Hadron Collider allow for a robust and precise characterisation of the electro-weak interactions of the top quark. We present the results of a global analysis at next-to-leading order precision including…
The large top Yukawa coupling results in the top quark contributing significantly to the quantum correction of the Higgs mass term. Traditionally, this effect is canceled by the presence of top partners in symmetry-based models. However,…
Unlike other examples of fermion pair production in e+ e- collisions, we show that top-quark pairs are produced in an essentially unique spin configuration in polarized e+ e- colliders at all energies. Since the directions of the…
In this work, $\gamma^{(\ast)}\gamma^{(\ast)}$ interactions in electron-positron collisions are studied across both low- and high-energy regimes. The analysis includes contributions from the Vector Meson Dominance (VMD) model (via Reggeon…
Top quark pair production at photon-photon colliders is studied in low scale quantum gravity scenario. From the dependence of the cross sections on the spin configuration of the top quark and anti-quark, we introduce a new observable, top…
Vector-like quarks, usually dubbed top partners, are a common presence in composite Higgs models. Being composite objects, their mass is expected to be of the order of their inverse size, that is the condensation scale of the new strong…
We describe our recent lattice study of SU(4) gauge theory with fermions in the fundamental and sextet representations. In this theory, a new type of baryon consists of quarks in both representations. The spectrum of these "chimera baryons"…
We consider the contribution of new strongly interacting sector, with a characteristic scale of half a TeV, to top quark production at the Tevatron. The color-octet, isosinglet analog of the $\rho$ meson in this theory is produced copiously…