Related papers: Two-fermion final states at International Linear C…
We consider the possibility of new physics giving rise to effective interactions of the form $e^+e^-Hf \bar f$, where $f$ represents a charged lepton $\ell$ or a (light) quark $q$, and $H$ the recently discovered Higgs boson. Such vertices…
We discuss the sensitivity of the processes e+e- to b b(bar), e+e- to t t(bar) and gamma gamma to H to certain residual New Physics interactions affecting the heavy quark and Higgs boson sector. With a linear collider of 500 GeV, one should…
The production of an intermediate-mass Higgs boson in processes of the kind $e^+ e^- \to 6$ fermions at the energies of future linear colliders is studied. The recently developed and fully automatic algorithm/code ALPHA is used to compute…
In this paper, the pair production of charged Higgs bosons at possible future e+e- linear colliders is studied. Multi-jet final states are considered and the combinatorial, hadronic and genuine tbtb backgrounds are reduced thanks to a…
We discuss the status and some ongoing upgrades of the ZFITTER program for applications at e+e- colliders LEP1/SLC, LEP2, GigaZ, and TESLA. The inclusion of top quark pair production is under work.
The observability of charged Higgs $ H^{\pm} $ has been investigated at future lepton collider by assuming type-I 2HDM, at a centre of mass energy $ \sqrt{s}=1.5$ TeV. The signal process chain is $ e^{+}e^{-} \rightarrow Z^{*}/…
A core prediction of natural Supersymmetry is the existence of four light higgsinos not too far above the mass of the $Z$ boson. The small mass splittings amongst the higgsinos -- typically 5-20\,GeV -- imply very little visible energy…
We analyze the potentiality of the new generation of $e^+e^-$ linear colliders to search for large extra dimensions via the production of fermion pairs in association with Kaluza-Klein gravitons (G), i.e. $e^+e^- \leftarrow f\bar{f}G$. This…
A "Higgs factory", an electron-positron collider with center-of-mass energy of about 250 GeV, will measure the cross section of the Higgsstrahlung process, $e^+e^-\rightarrow hZ$, with sub-percent precision. This measurement is sensitive to…
The Higgs triplet model (HTM) predicts the existence of a pair of doubly charged Higgs bosons $H^{\pm \pm}$. Single production of $H^{\pm \pm}$ via e collision at the next generation e+e- International Linear Collider (ILC) and the Large…
We study the discovery prospects for a doubly charged Higgs boson $H^{\pm\pm}$ in the 2-Higgs Doublet Model with type-II seesaw (2HDMcT) at future $e^+e^-$ colliders. Focusing on the three-body channels $e^+e^- \to…
We study pair production of leptoquarks in e+e- annihilation at linear colliders. A detailed simulation including beamstrahlung and initial state radiation, leptoquark decay and hadronization, as well as detector smearing, is performed.…
In the minimal Universal Extra Dimension model, single production of n = 2 gauge bosons provides a unique discriminating feature from supersymmetry. We discuss how the proposed International Linear Collider can act as a n = 2 factory, much…
We study associated Higgs production with a photon at electron-positron colliders, $e^+e^-\to h\gamma$, in various extended Higgs models, such as the inert doublet model (IDM), the inert triplet model (ITM) and the two Higgs doublet model…
Measurements of Zgamma* production are presented using data collected by the DELPHI detector at centre-of-mass energies ranging from 183 to 209 GeV, corresponding to an integrated luminosity of about 667 pb^{-1}. The measurements cover a…
We examine the effects of the extended gauge sector of the Littlest Higgs model in high energy e+e- collisions. We find that the search reach in e+e- -> f fbar at a 500 GeV center-of-mass energy International Linear Collider covers…
In this paper, we will derive the cross section formula for the Higgs pair production at a linear $e^+e^-$ collider in models with large extra dimensions and study the feasibility of its measurement through realistic Monte Carlo…
A large, world-wide community of physicists is working to realise an exceptional physics program of energy-frontier, electron-positron collisions with the International Linear Collider (ILC). This program will begin with a central focus on…
We study the diagnostic power of future $e^+e^-$ colliders with ${\sqrt {s}} = 500$ GeV (the New Large Collider ($NLC$)) for a model independent determination of the $Z'$ gauge couplings to quarks and leptons. The interference of the $Z'$…
We explore the discovery potential of Higgs pair production at a 100 TeV collider via full leptonic mode. The same mode can be explored at the LHC when Higgs pair production is enhanced by new physics. We examine two types of fully leptonic…