Related papers: Off resonance background effects in e+e- -> t anti…
We report a detailed simulation study of the search for $s$-channel Higgs boson production in $e^+e^-$ collisions at a center-of-mass (c.m.) energy of $\sqrt{s}=125\,\mathrm{GeV}$ at the CERN Future Circular Collider (FCC-ee), as a means to…
The complete matrix element for $e^+e^-\ar b\bar bW^+W^-$ has been computed at tree--level and applied to $Z^0H^0$ production followed by $Z^0\ar b\bar b$ and $H^0\ar W^+W^-$, keeping into account all irreducible backgrounds, which are…
We advocate a search for an extended scalar sector at the LHC via $hh$ production, where $h$ is the 125 GeV Higgs boson. A resonance feature in the $hh$ invariant mass is a smoking gun of an $s$-channel heavy Higgs resonance, $H$. With one…
We calculate the cross section for e+e- --> H+ e- nubar in the two-Higgs-doublet model from one-loop diagrams involving top and bottom quarks. This process offers the possibility of producing the charged Higgs boson at the e+e- collider…
The search for the heavy charged Higgs (mH+ > mtop) has been mainly based on the off-shell top pair production process. However, resonance production in s-channel single top events is an important channel to search for this particle. In a…
We present an analysis of Higgs-boson production in association with a top-quark pair at the LHC investigating in particular the final state consisting of four b jets, two jets, one identified charged lepton and missing energy. We consider…
We suggest searching for the charged Higgs boson at the Large Hadron Collider (LHC) via $cg \to b H^+ \to b t \bar b$. In the general two Higgs Doublet Model, extra top Yukawa couplings $\rho_{tc}$ and $\rho_{tt}$ can drive the…
Production cross sections for t\bar{t} and t\bar{t}j events at hadron colliders are calculated, including finite width effects and off resonance contributions for the entire decay chain, t --> bW --> b\ell\nu, for both top quarks. Resulting…
It is well known that $CP$-violating coupling of the Yukawa interaction of top-quark is a promising candidate of a new source of $CP$ violation effect. Precisely measurement of its $CP$ properties is crucial for understanding new physics…
We examine the detection of the intermediate-mass Higgs boson (IMH) at LHC through the associate production channel pp-->t+(anti-t)+H+X-->l+photon+ photon+X'. It is shown that by applying kinematic cuts or b-tagging on the final state jets,…
The completion of the third-order QCD corrections to the inclusive top-pair production cross section near threshold demonstrates that the strong dynamics is under control at the few percent level. In this paper we consider the effects of…
The complete matrix element for $e^+e^-\ar W^+W^-\bar b b$ is computed at tree level and applied to: {\bf a)} $\bar t t$ production and decay ; {\bf b)} $ZH$ production followed by $Z\ar \bar bb$ and $H\ar WW$. In both cases we include…
Photon-photon linear colliders can be realized by laser back-scattering technique on the next generation linear $e^+e^-$ colliders. Here the associated productions of an intermediate mass Higgs (IMH) or Z-boson with $t \bar t$ pair in…
We discuss associated production of a Higgs boson with a pair of $t {\bar t}$ quarks at a future high energy $e^+e^-$ collider. The process $e^+e^-\to t {\bar t}h$ is particularly sensitive to the presence of new physics and we consider the…
We calculate the subprocess q qbar --> t tbar H which contributes to the signal for detection of a light `intermediate mass' Higgs boson at the LHC and SSC in the isolated lepton and two isolated photons mode. This enhances the gg --> t…
Associated production of the Higgs boson with a single top quark proceeds through Feynman diagrams, which are either proportional to the hWW, top-Yukawa, or the bottom-Yukawa couplings. It was shown in literature that the interference…
Electroweak symmetry breaking and the origin of mass of fermion and boson are fundamental questions to understand particle physics. The essential piece of this symmetry breaking, the Higgs boson, is the most probable particle to be…
We present a search for the production of a Higgs boson in association with a single top quark ($tHq$), using data samples collected by the CMS detector in $pp$ collisions at center-of-mass energy of 8 TeV corresponding to integrated…
The measurement of the Yukawa coupling of the top quark is one important goal of particle physics after the discovery of the Higgs boson. There are two processes that offer the possibility to directly measure the Yukawa coupling of the top…
Measurement of the Yukawa interaction between the top quark and the Higgs boson should be useful to clarify the mechanism of fermion mass generation. We discuss the impact of non-standard interactions characterized by dimension-six…