Related papers: A hybrid 4$^{\textrm{th}}$ generation: Technicolor…
A search for pair-produced vector-like quarks using events with exactly one lepton ($e$ or $\mu$), at least four jets including at least one $b$-tagged jet, and large missing transverse momentum is presented. Data from proton-proton…
In multiscale and topcolor-assisted models of walking technicolor, relatively light spin-one technihadrons $\rho_T$ and $\omega_T$ exist and are expected to decay as $\rho_T \to W \pi_T, Z \pi_T$ and $\omega_T \to \gamma \pi_T$. For…
Technicolor, with extended technicolor, is the theory of dynamical electroweak and flavor symmetry breaking at energies far below the Planck scale. To motivate it, I describe the most important difficulties of the standard electroweak model…
Scenarios seeking to address the issue of electroweak symmetry breaking often have heavy colored gauge bosons coupling preferentially to the top quark. Considering the bulk Randall-Sundrum as a typical example, we consider the prospects of…
We study the production of top-antitop pairs at the Large Hadron Collider as a testbed for discovering heavy Z' bosons belonging to a composite Higgs model, as, in this scenario, such new gauge interaction states are sizeably coupled to the…
I discuss production and detection at the Tevatron $\pbarp$ collider of pairs of light ($\mpi = 100$--$200\,\gev$) color--singlet technipions that are expected in all nonminimal models of technicolor. Gluon fusion production rates can be as…
We explore the possibility of a fourth generation in the gauge-coupling-unified, minimal supersymmetric (MSSM) framework. We find that a sequential fourth generation (with a heavy neutrino $\nu'$) can still fit, surviving all present…
Precise measurements of the properties of the top quark test the Standard Model (SM) and can be used to constrain new physics models. The top quark pair charge asymmetry is an asymmetry predicted to occur beyond leading-order QCD in the SM,…
Top quark production in the process $e^+e^- \rightarrow t\bar{t}$ at a future linear electron positron collider with polarized beams is a powerful tool to determine the scale of new physics. Studies at the $\ttbar$ threshold will allow for…
We propose to probe the topcolor-assisted technicolor (TC2) model from the top-charm associated productions at the LHC, which are highly suppressed in the Standard Model. Due to the flavor-changing couplings of the top quark with the…
A search for pair production of third-generation scalar leptoquarks and supersymmetric top quark partners, top squarks, in final states involving tau leptons and bottom quarks is presented. The search uses events from a data sample of…
In composite Higgs (CH) models, large mixings between the top quark and the new strongly interacting sector are required to generate its sizeable Yukawa coupling. Precise measurements involving top as well as left-handed bottom quarks…
We study the effects of a fourth generation t' quark in various extensions of the standard model. In the Randall-Sundrum model, the decay t'--> t Z has a large branching ratio that could be detected at the Large Hadron Collider (LHC). We…
We study the pair production of scalar top-quark partners decaying to a top-quark pair plus large missing energy at the LHC, a signature which appears in numerous models that address outstanding problems at the TeV-scale. The severe…
We analyse the impact of LHC and Tevatron Higgs data on the viability of the Standard Model with a sequential fourth generation (SM4), assuming Dirac neutrinos and a Higgs mass of 125 GeV. To this end we perform a combined fit to the signal…
We study vector boson fusion production of new scalar singlets at high energy lepton colliders. We find that CLIC has the potential to test single production cross-sections of a few tens of attobarns in di-Higgs and di-boson final states.…
We study a second CP symmetry compatible with the $A_4$ flavor group, which interchanges the representations $\mathbf{1}'$ and $\mathbf{1}"$. We analyze the lepton mixing patterns arising from the $A_4$ and CP symmetry broken to residual…
A search for vectorlike quarks is presented, which targets their decay into a $Z$ boson and a third-generation Standard Model quark. In the case of a vectorlike quark $T$ ($B$) with charge $+2/3e$ ($-1/3e$), the decay searched for is $T…
It is shown that a technicolor theory containing a color-octet technipion, usually denoted by $P^{0'}_{8}$, will give rise to an enhancement of $t \bar t$ production at the Tevatron, LHC and SSC, via the process $gg \rightarrow P^{0'}_{8}…
The large number of top quarks produced at the LHC and possible future hadron colliders allows to study rare decays of this particle. In many well motivated models of new physics, for example in non-minimal composite-Higgs models, the…