Related papers: Constraining heavy colored resonances from top-ant…
We investigate the production of beyond-the-standard-model color-sextet vector bosons at the Large Hadron Collider and their decay into a pair of same-sign top quarks. We demonstrate that the energy of the charged lepton from the top quark…
We study hypothetical gauge bosons that may produce dijet resonances at the LHC. Simple renormalizable models include leptophobic Z' bosons or colorons that have flavor-independent couplings and decay into a color-singlet or -octet…
We study the signal from the pair production of $t$-squarks at the Tevatron under the assumption that their two-body decay to charginos as well as their three-body decay to $W$ bosons is kinematically forbidden. In this case, the stop…
The charge asymmetry in hadronic top-antitop-quark production is a powerful test observable of perturbative quantum chromodynamics. Since its origin in terms of Feynman diagrams is distinct from charge-symmetric top-antitop production,…
The null search for the Higgs boson at the Tevatron implies strong constraints on heavy colored particles that increase the gluon-fusion induced production rate of the Higgs. We investigate the implications of the Tevatron exclusion limit…
In this paper, we investigate the anomalous chromoelectric and chromomagnetic dipole moments of the top quark through top pair production in association with two photons at the LHC. We first present the strategy to reconstruct this process…
In our latest paper "Search for anomalous top-gluon couplings at LHC revisited" in Eur. Phys. J. C65 (2010), 127-135 (arXiv:0910.3049 [hep-ph]), we studied possible effects of nonstandard top-gluon couplings through the chromoelectric and…
We discuss a model in which the third generation fermions undergo a different $SU(2)$ weak interaction from the first two generation fermions. In general, a flavor changing neutral current interaction is expected. Constrained by the…
The Standard Model provides an excellent description of the observables measured at high energy lepton and hadron colliders. However, measurements of the forward-backward asymmetry of the bottom quark at LEP suggest that the effective…
We study the charge asymmetry between the $t$ and $\bar t$ quark at the LHC, when they are produced in association with a $W$ boson. Though sizably reducing the cross section with respect to the inclusive production, requiring a $W$ boson…
A search is presented for additional scalar (H) or pseudoscalar (A) Higgs bosons decaying to a top quark pair in proton-proton collisions at a center-of-mass energy of 13 TeV. The data set analyzed corresponds to an integrated luminosity of…
We study the process of single-top production in association with a charged Higgs boson at the LHC and discuss how top-quark polarization and an azimuthal asymmetry $A_\varphi$ of the charged lepton from top decay can be used in some…
The LHC is now studying in detail the couplings of the Higgs boson in order to determine if there is new physics. Many recent studies have examined the available fits to Higgs couplings from the perspective of constraining two Higgs doublet…
We present a search for charged Higgs bosons in decays of pair-produced top quarks in pbar p collisions at sqrt(s) = 1.8 TeV using 62.2 pb^-1 of data recorded by the D0 detector at the Fermilab Tevatron collider. No evidence is found for…
We investigate collider signals for gauged flavor symmetries that have been proposed in models of dynamical electroweak symmetry breaking and fermion mass generation. We consider the limits on the masses of the gauge bosons in these models…
The light axigluon model can explain the Tevatron $t\overline{t}$ forward-backward asymmetry and at the same time satisfy the constraints from the electroweak precision measurement and the $ATLAS$ and $CMS$ data, which induces the flavor…
This article presents a measurement of the top quark mass using the CDF II detector at Fermilab. Colliding beams of protons and anti-protons at Fermilab's Tevatron (sqrt{s}=1.96 TeV) produce top/anti-top pairs, which decay to W^+W^-bbbar;…
We investigate trilepton final states to probe top anomalous couplings at the Large Hadron Collider. We focus on events originating from the associated production of a single top quark with a Z-boson, a channel sensitive to several…
A search for flavour-changing neutral current decays of a top quark to an up-type quark ($q=u, c$) and the Standard Model Higgs boson, where the Higgs boson decays to $b\bar{b}$, is presented. The analysis searches for top quark pair events…
Weakly-coupled models for the 750 GeV diphoton resonance often invoke new particles carrying both color and/or electric charges to mediate loop-induced couplings of the resonance to two gluons and two photons. The new colored particles may…