Related papers: Possible Resonances in $\mu^+e^- \to \mu^- e^+$ Co…
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 $\mu$-$e$…
Ultralight scalar dark matter may induce apparent oscillations of the muon mass, which may be directly probed via temporal shifts in the spectra of muonium and muonic atoms. Existing datasets and ongoing spectroscopy measurements with…
We investigate the sensitivity of e- gamma ---> nu_e nu_mu(bar) mu- to extra charged gauge bosons. The sensitivity is much below that of e-e+ ---> nu nu(bar) gamma. We conclude that e- gamma ---> d u(bar) nu_e and e- gamma ---> f f(bar) e-…
New physics motivated by muonic puzzles (proton radius and muon $g-2$ discrepancies) is studied. Using a light scalar boson $\phi$, assuming Yukawa interactions, accounts for these muonic puzzles simultaneously. Our previous work limits the…
We study $\mu^+\mu^-$ collision with production of some state $F$ (for example, $F= W^+$) and $(e\bar\nu)$ system with the effective mass, which is less than muon mass. In this case the momentum $k$, transferred from $\mu$ to $e\bar\nu$…
Production of a single doubly charged Higgs boson $Delta^{--}$ in polarized $e^+e^-$ and $e^+\gamma$ collision modes of the linear collider have been investigated. The mass range of $Delta^{--}$ to be probed extends up to the collision…
We show that bottom-strange production at a high-energy muon collider, $\mu^+ \mu^- \to b s$, is a sensitive probe of new physics. We consider the full set of four-fermion contact interactions that contribute to this process at dimension 6,…
Using an effective lagrangian description we analyze possible new physics contributions to the most relevant muon number violating processes: $\mu \to e \gamma$ and $\mu$--$e$ conversion in nuclei. We identify a general class of models in…
A muon collider is expected to produce a high intensity neutrino beam which is an admixture of either $\nu_{\mu}+\bar{\nu_e}$ or $\bar{\nu}_{\mu} +\nu_e$ which can can be directed to underground detectors far away from the source. It will…
We consider the possibility of observing deviations from the Standard Model gauge-boson self-couplings at future $e\gamma$ colliders. We concentrate on the process $e^-\gamma \rightarrow \nu W^- Z$, which is particularly sensitive to the…
Two-photon collisions at the e$^+$e$^-$ colliders allow to investigate the formation and the properties of resonant states in a very clean experimental environment. A remarkable number of new results have been recently obtained giving…
We compare two most relevant loop induced muon number violating processes, \mu --> e \gamma and \mu-e conversion in nuclei, in constraining new physics. Because of much richer structure of the latter process it may be enhanced with respect…
We derive supernova (SN) bounds on muon-philic bosons, taking advantage of the recent emergence of muonic SN models. Our main innovations are to consider scalars $\phi$ in addition to pseudoscalars $a$ and to include systematically the…
A nonconventional $U(1)_{e-\mu}$ gauge model is proposed to explain the unexpected anomalous magnetic moments of the electron and muon (lepton $g-2$), where only the right-handed electron and muon in the standard model carry the…
This paper describes the search for a high-mass narrow-width scalar particle decaying into a Z boson and a photon. The analysis is performed using proton-proton collision data recorded with the CMS detector at the LHC at center-of-mass…
We discuss the discovery potential of a promising signals, $3 \times \mu^+ \mu^-$ at a $\mu^+ \mu^-$ collider and $\mu^+ \mu^+ \mu^+ \mu^+ \mu^- \mu^- $ at a $\mu^+ \mu^+$ collider, that are obtained via production of $Z'$ and a new scalar…
Motivated by the recent Super-Kamiokande results on atmospheric neutrinos, we incorporate massive neutrinos, with large angle oscillation between the second and third generations, in a scenario with R-parity violating supersymmetry. We…
Recently, the CMS Collaboration performed a search on a new resonance decaying to $e^\pm\mu^\mp$ in the mass range of 110 GeV to 160 GeV. The search also hints a possible excess at 146 GeV with a $3.8\sigma~(2.8\sigma)$ of local (global)…
We study the lepton-flavor-violating reaction $\mu^+ e^- \to e^+ e^-$ within two extensions of the standard model that include heavy neutrinos. The reaction is studied in the low energy limit in the form of muonium decay $M\to e^+ e^-$ and…
I consider the process $\mu^+\mu^-\to e\bar{\nu}W^+$ in the case when the effective mass of the $(e\bar\nu)$ system than the muon mass. In this case the momentum transferred from the initial muon to the $e\bar\nu$ system (the virtual…