Related papers: Single Neutral Heavy Lepton Production at e^+e^- a…
New heavy Majorana and Dirac neutrinos production at future electron-muon colliders are investigated. The production of a single heavy neutrino is shown to be more relevant than pair production when comparing cross sections and neutrino…
The discovery potential for detecting new heavy Majorana and Dirac neutrinos at some recently proposed high energy $e^+e^-$ colliders is discussed. These new particles are suggested by grand unified theories and superstring-inspired models.…
We study the single production of heavy neutrinos via the processes $e^-e^+ \to \nu N$ and $e^-\gamma \to W^- N$ at future linear colliders. As a base of our considerations we take a wide class of models, both with vanishing and…
We discuss the production, at high--energy e$^+$e$^-$ linear colliders, of new heavy fermions predicted by extensions of the Standard Model. We analyze in great details the various signals and the corresponding backgrounds for both pair…
The production of heavy and light neutrinos in $e^+e^-$ future colliders is considered. The cross section for the process $e^+e^- \rightarrow \nu N$ and then the heavy neutrino decay $N \rightarrow W^{\pm} e^{\mp}$ is determined for…
We examine two processes, the neutrino production process e^+e^- ---> N\nu and the inverse neutrinoless double-beta decay process e^-e^- --->W^-W^- as possible places for discovering heavy neutrinos in future lepton linear colliders. The…
Possibilities for detecting heavy Majorana neutrinos ($N$'s) at future $e{\mu}$ colliders are investigated. In contrast to the $e^-e^+$ colliders (LEP200 and NLC), the center-of-mass (CMS) energies achieved at $e{\mu}$ colliders can be much…
Single $W_R$ production in $e^-e^-$ collisions at the NLC can be used to probe the Majorana nature of the heavy neutrinos present in the Left-Right Symmetric Model below the kinematic threshold for their direct production. For colliders in…
Neutrinos are among the most mysterious particles in nature. Their mass hierarchy and oscillations, as well as their antiparticle properties, are being intensively studied in experiments around the world. Moreover, in many models of physics…
We investigate possibilities for detecting heavy Majorana neutrinos ($N$'s) in $e^+e^-$ at LEP200 and future Linear Colliders. We concentrate on the processes where the pairs of intermediate heavy $N$'s produce a clear signal of total…
We study the LHC discovery potential for heavy Majorana neutrino singlets in the process pp -> W+ -> l+ N -> l+ l+ jj (l=e,mu) plus its charge conjugate. With a fast detector simulation we show that backgrounds involving two like-sign…
We study signatures of heavy Majorana neutrinos at e- gamma colliders. Since these particles violate lepton number, they can give rise to the reactions e- gamma -> W- W- e+ and e- gamma -> W+ mu- mu- nu. The Standard Model background…
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.…
We present the first study of the production of a Standard Model Higgs boson at a lepton collider in association with a pair of W bosons, $e^+_{} e^-_{} \to W^+_{} W^-_{} H$, in the inverse seesaw model. Taking into account all relevant…
We consider the production of a heavy neutrino and its possible signals at the Large Hadron-electron Collider (LHeC) in the context of an inverse-seesaw model for neutrino mass generation. The inverse seesaw model extends the Standard Model…
Neutrino masses could originate in seesaw models testable at colliders, with light mediators and an approximate lepton number symmetry. The minimal model of this type contains two quasi-degenerate Majorana fermions forming a pseudo-Dirac…
A charged Higgs pair can be produced at an ee collider through a t-channel exchange of a heavy neutrino (N) via e^+ e^- -> H^+ H^- and, if N is a Majorana particle, also via the lepton number violating (LNV) like-sign reaction e^\pm e^\pm…
Many extensions of the Standard Model of particle physics contain new electrically-neutral fermions. Should one of these particles be discovered, questions will naturally arise regarding its nature. For instance: is it a self-conjugate…
We analyze the capacity of future $Z$-factories to search for heavy neutrinos with their mass from 10 to 85 GeV. The heavy neutrinos $N$ are considered to be produced via the process $e^+e^-\to Z\to \nu N$ and to decay into an electron or…
We study the phenomenology of a Standard Model (SM) extension with two charged singlet scalars and three right handed (RH) neutrinos at an electron-positron collider. In this model, the neutrino mass is generated radiatively at three-loop,…