Related papers: Lower Bounds on Bilepton Processes at e-e- and mu-…
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…
A promising direction to find physics beyond the standard model is to look for violation of $L_{e,\mu,\tau}$ conservation. In particular the process $e^- e^- \to \mu^- \mu^-$ with the exchange of a gauge bilepton has a striking signal…
There are serious discussions for building a muon collider with $\mu^{+}\mu^{-}$ collisions at c.o.m. energies up to 4 TeV. We point out that the bileptonic gauge bosons predicted in some extensions of the Standard Model would be readily…
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.…
We study the phenomenology of the type-II seesaw model at a linear e^-e^- collider. We show that the process e^-e^- \rightarrow alpha^-beta^- (alpha, beta = e, mu, tau being charged leptons) mediated by a doubly charged scalar is very…
We analyze the prospects for discovering and unraveling the nature of doubly-charged bileptons at a linear collider of the next generation running in its electron-electron colliding mode. We stress the importance of initial state radiation,…
Theoretical backgound for bileptonic gauge bosons is reviewed, both the SU(15) GUT model and the 3-3-1 model. Then the mass limits for bileptons are discussed coming from $e^+e^-$ scattering, polarized muon decay and muonium-antimuonium…
We study the process $e^- + e^+ \to e^+ + e^+ + e^- + e^-$ for ILC and CLIC energy regimes, in the minimal 3-3-1 model framework. The main contributions, for the production of two bileptons each one decaying into two same-sign leptons, come…
We show that the accumulated LEP-II data taken at $\sqrt{s} =$ 130 to 206 GeV can establish more restrictive bounds on doubly charged bileptons couplings and masses than any other experiment so far. We also analyze the discovery potential…
We present the first detailed computation of the conversion of a bound muon into an electron mediated by a doubly charged $SU(2)$ singlet scalar. Although such particles are not too exotic, up to now their contribution to $\mu$-$e$…
We study the production of bileptons, new gauge boson of lepton number two, in the minimal 3 - 3 - 1 model in high energy electron - photon collisions. If the bilepton masses are in the range of 300 GeV the reaction will give observable…
We revisit the process of inverse neutrino-less double beta decay (e e -> W W) at future linear colliders. The cases of Majorana neutrino and Higgs triplet exchange are considered. We also discuss the processes e mu -> W W and mu mu -> W W,…
The electric and magnetic dipole moments of the electron and of the muon provide stringent tests of the Standard Model and sensitive probes of new physics. By contrast, the corresponding dipole moments of the $\tau$ lepton remain weakly…
It is well known that at linear e^+e^-(e^-e^-) colliders using laser backscattering one can obtain colliding gamma-gamma, gamma-electron beams with energy and luminosity comparable to those in e^+e^- collisions. In this paper, it is…
The cross-section for the process $\gamma + A \to \mu^+ + \mu^- + X$ is studied where the photon energy is of the order of several hundreds of GeV and where one of the leptons is scattered to large angles. This is of practical importance…
Motivated by the interest in lepton number violating processes, we study the connection between the rate of Z -> mu e decay and those of the low-energy processes mu ->3 e, and mu -> e conversion in nuclear field. We show that if the vector…
We search for doubly charged scalar bileptons via $ \text{e}^{-}\text{e}^{-}\to \mu^{-}\mu^{-}$ and $ \text{e}^{-}\text{e}^{-}\to \text{e}^{-}\text{e}^{-}$ processes at linear collider energies by considering initial and final state…
We discuss a low energy $e^+e^-$ collider for production of the not yet observed ($\mu^+\mu^-$) bound system (dimuonium). Collider with large crossing angle for $e^+e^-$ beams intersection produces dimuonium with non-zero momentum,…
I review possible signals at hadron colliders of bileptons, namely doubly-charged vectors or scalars with lepton number L=+/- 2, as predicted by a 331 model, based on a SU(3)_c x SU(3)_L x U(1)_X symmetry. In particular, I account for a…
The anomalous magnetic moments of leptons represent excellent probes of the Standard Model and therefore also of possible new physics effects. In particular, the persisting hint of new physics in the muon $g$-2 motivates the investigation…