Related papers: Single Leptoquark Production at $e^+e^-$ and $\gam…
This paper presents a search for the pair production of top squarks in events with a single isolated electron or muon, jets, large missing transverse momentum, and large transverse mass. The data sample corresponds to an integrated…
The left-right twin Higgs model contains a new vector-like heavy top quark, which mixes with the SM-like top quark. In this work, we studied the single vector-like top partner production via process $e^{-}\gamma \rightarrow \nu_{e}\bar{T}b$…
We investigate the potential of a high-energy $\gamma\gamma$ collider to detect an anomalous $\bar t q \gamma$ coupling from observation of the reaction $\gamma \gamma \to t\bar q$, $\bar t q$, where $q=c$ or $u$. We find that with…
We studied single $W$ boson production in high energy $e\gamma$ collisions and the sensitivity of various observables to the $WW\gamma$ gauge boson coupling by evaluating the helicity amplitudes of all Feynman diagrams which contribute to…
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…
The new colored vector-like heavy fermion $T$ is a crucial prediction in little Higgs models, which plays a key role in breaking the electroweak symmetry. The littlest Higgs model is the most economical one among various little Higgs…
We present a detailed study of the anomalous single fourth generation $t'$ quark production within the dominant Standard Model(SM) decay modes at future $e^+e^-$ colliders. We calculate the signal and background cross sections in the mass…
The prospects for producing leptoquarks (LQs) in ultrahigh-energy (UHE) neutrino nucleon collisions are re-examined in the light of recent interpretations of HERA data in terms of leptoquark production. We update predictions for…
A search for pair-production of first generation scalar leptoquarks is performed in the final state containing an electron, a neutrino, and at least two jets using proton-proton collision data at sqrt(s)=7 TeV. The data were collected by…
The ATLAS experiment at the LHC at CERN has analyzed 2010 and 2011 data looking for electroweak production of single top quarks in the lepton+jets and di-lepton final states. The production cross section for the t-channel process is…
Single production of the doubly charged scalars $\Phi^{\pm\pm}$ via $e\gamma$, $ep$ and $pp$ collisions is studied in the context of the little Higgs$(LH)$ model. Our numerical results show that the new particles $\Phi^{\pm\pm}$ can be…
The process e+e- to gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 56.2 pb-1 taken at a centre-of-mass energy of 183 GeV. The measured…
We compute the total cross-section and invariant mass distribution for heavy-quark pair production in $e^+e^-$ annihilation at the next-to-next-to-next-to-leading order in QCD. The obtained results are expressed as piecewise functions…
The study of top-quark properties will be a central aspect of the physics programme of any future lepton collider. In this article, we investigate the production of top-quark pairs in the semi-leptonic decay channel in $\rm e^+e^-$…
We study scalar leptoquark production at TESLA and CLIC based e-gamma colliders. Both direct and resolved contributions to the cross section are examined. We find that the masses of scalar leptoquarks can be probed up to about 0.9 TeV at…
The signatures of heavy fermionic triplets ($\Sigma$) arising in scenarios like Type III seesaw model are probed through their direct production and subsequent decay at high energy electron-positron collider. Unlike the case of LHC, the…
We discuss the production of heavy leptons at a future high--energy $e^+e^-$ linear collider with a center of mass energy of 500 GeV. Signals and backgrounds are analyzed for their single production in association with ordinary leptons.…
A search for leptoquark pair production decaying into $te^- \bar{t}e^+$ or $t\mu^- \bar{t}\mu^+$ in final states with multiple leptons is presented. The search is based on a dataset of $pp$ collisions at $\sqrt{s}$=13 TeV recorded with the…
The observation of the electroweak production of single-top-quarks is made using 255 $\text{pb}^{-1}$ of proton-proton collision data recorded at $\sqrt{s} = 5.02$ TeV with the ATLAS detector at the Large Hadron Collider. An event selection…
A search for pair production of second-generation scalar leptoquarks in the final state with two muons and two jets is performed using proton-proton collision data at sqrt(s) = 7 TeV collected by the CMS detector at the LHC. The data sample…