Related papers: Bileptons - Present Constraints and Future Prospec…
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…
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…
The search reaches for new gauge bosons at future hadron and lepton colliders are summarized for a variety of extended gauge models. Experiments at these energies will vastly improve over present limits and will easily discover a $Z'$…
Recently, Kajiyama, Okada and Yagyu (KOY) proposed an electron/muon specific two Higgs doublet model. In this model, an S3 symmetry suppresses flavor changing neutral currents instead of a Z2 symmetry. In the "Type I" version of the model,…
We present a detailed discussion of the lepton flavour and number violating conversion of bound muons into positrons. This process is a viable alternative to neutrinoless double beta decay and, given that experiments on ordinary $\mu^-$-…
This is a short review of present and future limits on new neutral gauge bosons, in particular on hadrophilic or leptophobic $Z'$s recently proposed to interpret the observed fluctuations of $\Gamma _{c,b}$ at LEP. Light gauge bosons…
Assuming the existence of a gauge boson $X$ which couples to $B - 3 L_\tau$, we discuss the present experimental constraints on $g_X$ and $m_X$ from $Z \to l^+ l^-$ and $Z \to \bar f f X~(f = q, \nu_\tau, \tau)$. We also discuss the…
We consider the processes $e^{+}e^{-}\rightarrow \ell^{+} \ell^{\prime -}\nu \bar{\nu}^{\prime}$, including all possible charged lepton combinations, with regard to measuring parameters characterizing the $W$ boson. We calculate at what…
Two photon collisions offer a variety of physics studies that can be performed at the future electron-positron colliders. Using the planned CEPC parameters as a benchmark we consider several topics to be studied in the two-photon…
The only possible doubly-charged scalar decays into two Standard Model particles are into pairs of same-sign charged leptons, H$^{\pm\pm}\rightarrow {l}^\pm {l}^\pm, {l} = e, \mu, \tau$, or gauge bosons, H$^{\pm\pm}\rightarrow W^\pm W^\pm$;…
Several popular extensions of the Standard Model predict extra vector fields that transform as triplets under the gauge group SU(2)_L. These multiplets contain Z' and W' bosons, with masses and couplings related by gauge invariance. We…
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 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…
If sleptons are produced at LEP II or the Next Linear Collider, lepton flavor violation can be probed at a level significantly below the current bounds from rare processes, such as $\mu \to e\gamma$. Polarizable $e^-$ beams and the $e^-e^-$…
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…
By introducing a set of new triplet leptons (with nonzero hypercharge) that can Yukawa couple to their Standard Model counterparts, new sources of tree-level flavor changing currents are induced via mixing. In this work, we study some of…
We study the capabilities of future electron-positron Linear Colliders, with centre-of-mass energy at the TeV scale, in accessing the parameter space of a $Z'$ boson within the minimal $B-L$ model. In such a model, wherein the Standard…
The Higgs sector of the standard model can be extended by introducing an $SU(2)_L$ Higgs triplet $\Delta$ to generate the tiny neutrino masses in the framework of type-II seesaw mechanism. In this paper, we study the pair production of the…
We present recent developments in the diagnostic study of heavy gauge bosons at future colliders with the emphasis on the determination of gauge couplings of $Z'$ to quarks and leptons. Proposed diagnostic probes at future hadron colliders…
A heavy triplet of leptons $(\Sigma^+, \Sigma^0, \Sigma^-)_R$ per family is proposed as the possible anchor of a small seesaw neutrino mass. A new U(1) gauge symmetry is then also possible, and the associated gauge boson $X$ may be…