Related papers: Single production of excited spin-3/2 neutrinos at…
A search for excited lepton production in e+e- collisions was performed using the data collected by the DELPHI detector at LEP at centre-of-mass energies ranging from 189 GeV to 209 GeV, corresponding to an integrated luminosity of…
A proposed future ultra high energy collider such as the Future Circular Collider is expected to produce intense and collimated neutrino beams from weak hadron decays. In this study, we estimate the production yields of such neutrinos from…
A search for charged and neutral excited leptons is performed in 217 pb^-1 of e+e- collision data collected with the L3 detector at LEP at centre-of-mass energies from 202 GeV up to 209 GeV. The pair- and single-production mechanisms of…
Sterile neutrinos are among the most attractive extensions of the SM to generate the light neutrino masses observed in neutrino oscillation experiments. When the sterile neutrinos are subject to a protective symmetry, they can have masses…
A possibility to measure the spin and spin-spin correlations of a chargino pair is investigated in the process electron positron -> chargino_1 anti-chargino_1 -> (neutralino_1 quark anti-quark) (neutralino_1 quark anti-quark) at future…
Possible single productions of the fourth standard model generation neutrino via anomalous interactions at the future ep colliders are studied. Signatures of such anomalous processes and backgrounds are discussed in detail. Discovery limits…
We summarize the potential of high--energy $\ee$ linear colliders for discovering, and in case of discovery, for studying the signals of extended gauge models. We will mainly focus on the virtual signals of new neutral gauge bosons and on…
We study the single chargino production $e^+ e^- \to \tilde \chi^{\pm} \mu^{\mp}$ at linear colliders which occurs through the $\l_{121}$ R-parity violating coupling constant. We focus on the final state containing 4 leptons and some…
We discuss possible deviations from QED produced by a virtual excited spin-3/2 lepton in the reaction $e^+e^- \longrightarrow 2\gamma$. Data recorded by the OPAL Collaboration at a c.m. energy $\sqrt{s} = 183 GeV$ are used to establish…
As any $e^+e^-$ scattering process can be accompanied by a hard photon emission from the initial state radiation, the analysis of the energy spectrum and angular distributions of those photons can be used to search for hard processes with…
In recent years, with the enlightenment of some issues encountered at muon colliders, muon colliders have become more feasible for the high-energy physics community. For this reason, we studied single production of excited muon at muon…
Muon colliders provide an exciting new direction to expand the energy frontier of particle physics. We point out a new use of these facilities for neutrino and beyond the Standard Model physics using their main detectors. Muon decays along…
The present uncertainties in the knowledge of the neutrino cross sections for E_nu \sim 1 GeV, that is in the energy range most important for atmospheric and long baseline accelerator neutrinos, are large. These uncertainties do not play a…
The Wtb vertex can be probed on future colliders in the processes of single top production (LHC, pp mode, NLC, $\gamma e$ mode) and of top pair production (NLC, e^+ e^- mode). We analyse observables sensitive to anomalous Wtb couplings in…
We study the potential of high-energy linear $e^+e^-$ colliders for the production of gluino pairs within the Minimal Supersymmetric Standard Model (MSSM). In this model, the process $e^+e^-\to\tilde{g}\tilde{g}$ is mediated by quark/squark…
We analyze the associated production at future high--energy $e^+e^-$ colliders, of first generation sleptons with neutralinos and charginos in the modes $e^+ e^-$ and $e \gamma$, in the framework of the Minimal Supersymmetric extension of…
We study the production processes e^+ e^- -> chi^+_i chi^-_j, i,j=1,2, and e^+ e^- -> chi^0_m chi^0_n, m,n=1,...,4, working out the advantages of polarizing both beams. For e^+ e^- -> chi^+_1 chi^-_1 with chi^-_1 -> chi^0_1 e^- nu and e^+…
The exclusive vector meson production in electron-ion collisions for the energies of the future colliders is investigated. We present predictions for the coherent and incoherent $\phi$ and $J/\psi$ production in $eAu$ collisions considering…
The pair production of tau sneutrinos in $e^{+}e^{-}$ collisions and their subsequent decays are studied in a framework of the supersymmetric extension of the standard model. We present an analysis for the parameter space (BR vs. mass)…
We study the potential of an $e^+e^-$ linear collider to search for neutralino-neutralino-photon production. Our analysis shows that this signal is not viable under realistic expectations for electron beam polarization due to large Standard…