Related papers: Four Leptons Production in $e^-$ $e^+$ Collisions …
We show that the cross section of at least one of the s-channel processes e-e- (mu-mu-) --> l_i^- l_i^-, i=e,mu,tau, mediated by a doubly-charged scalar triplet bilepton is bounded from below and observable at a linear or muon collider if…
We examine very general four-point interactions arising from new physics and contributing to the Higgs production process e+e- -> HZ. We write all possible forms for these interactions consistent with Lorentz invariance. We allow the…
A selection of di-lepton events with significant missing transverse momentum has been performed using a total data sample of 77.0 pb-1 at e+e- centre-of-mass energies of 161 GeV, 172 GeV and 183 GeV. The observed numbers of events: four at…
The process of top-quark pair production followed by semileptonic decays at future high-energy e^+e^- linear colliders is investigated as a possible test of physics beyond the Standard Model. Assuming the most general non-standard forms for…
Events containing a pair of charged leptons and significant missing transverse momentum are selected from a data sample corresponding to a total integrated luminosity of 20.6 pb^-1 at centre-of-mass energies of 161 GeV and 172 GeV. The…
The process of top-quark pair production at future high-energy $e^+ e^-$ linear colliders has been investigated as a possible test of physics beyond the Standard Model. Non-standard interactions have been assumed both for the production and…
The process e^+e^- --> Z gamma, where the Z boson decays into hadrons or neutrinos, is studied with data collected with the L3 detector at LEP at centre-of-mass energies from 189 GeV up to 209 GeV. The cross sections are measured and found…
A detailed analysis of $Z^{'0}Z^{'0}$, $K^{+}K^{-}$ and $K^{0}\bar{K}^{0}$ pair production in $e^{+}e^{-}$ collisions is presented by using helicity amplitudes. The trilinear bosons couplings in the $SU(3)_{C}\otimes SU(3)_{L}\otimes…
We studied the production and signatures of doubly charged Higgs bosons in the process $\gamma e^- \rightarrow H^{--}E^+$, where $E^+$ is a heavy lepton, at the $e^-e^+$ International Linear Collider (ILC) and CERN Linear Collider (CLIC).…
We explore the effects of neutrino and electron mixing with exotic heavy leptons in the process e^+e^-\to W^+W^- within E_6 models. We examine the possibility of uniquely distinguishing and identifying such effects of heavy neutral lepton…
Bosons which couple to two leptons and carry lepton number L=2, generically called bileptons, appear in many extensions of the standard model. We review the present constraints on bilepton parameters coming from low and high energy data. In…
The production of the three normal neutrinos via $e^-e+$ collision at $Z$-boson peak (neutrino production in a Z-factory) is investigated thoroughly. The differences of $\nu_e$-pair production from $\nu_\mu$-pair and $\nu_\tau$-pair…
We study the pair production of $\tilde{l}_{4}$, which is the supersymmetric partner of the fourth family charged lepton, at the $e^{+}e^{-}$ colliders. It is shown that the investigation of this process at ILC/CLIC will give opportunity to…
Neutral gauge bosons beyond the Standard Model are becoming interesting as possible mediators to explain several experimental anomalies. They have small masses, below one GeV, and are referred to as dark photons, $U$, $A'$ or $Z'$ bosons.…
We analyze the production in $e^+e^-$ collisions of new heavy fermions stemming from extensions of the Standard Model. We write down the most general expression for the production of two heavy fermions and their subsequent decays, allowing…
Theoretical backgound for bileptonic gauge bosons is reviewed, both the SU(15) GUT model and the 3-3-1 model. Mass limits on bileptons are discussed coming from $e^+e^-$ scattering, polarized muon decay and muonium-antimuonium conversion.…
The T-odd leptons are the typical particles predicted by the littlest Higgs model with T-parity (LHT model) and the observation of these particles might be regarded as the direct evidence of the LHT model. In this paper, we investigate the…
We analyze the photon-initiated processes for production of $ e ^ + e ^- $ pairs in proton-nucleus collisions at LHC energy, taking into account both elastic processes and proton dissociations in the low-mass region (LMR) and…
The production at the LHC of exotic excited leptons of charge $Q = +2e$ is considered. Such states are predicted in composite models with extended isospin multiplets ($I_{W}=1$ and $I_{W}=3/2$). The coupling among these doubly charged…
Following the HL-LHC era, proposed lepton colliders highlight the need to study various important Higgs boson production mechanisms to precisely probe the Standard Model Higgs sector. We propose a novel mechanism $e^\pm \gamma \rightarrow…