Related papers: New physics in multi-lepton tau decays
In this paper, we study the phenomenology of a Dirac dark matter in the $L_\mu-L_\tau$ model and investigate the neutrino oscillation in the dark halo. Since dark matter couples to the muon neutrino and the tau neutrino with opposite sign…
Recent results from Super Kamiokande suggest $\nu_\mu-\nu_\tau$ mixing and hence lepton flavor violation. In supersymmetric models, this flavor violation may have implications for the pattern of slepton masses and mixings. Possible signals…
Neutrino oscillations as suggested by the recent Super-Kamiokande result imply that lepton numbers could be violated, and Z$\to \mu^{\mp} +\tau^{\pm}$ is a typical manifestation. We point out that for this mode, the GIM cancelation is much…
We search for the lepton flavor-violating "tau -> mu gamma" decay using 29.7 million tau pairs accumulated by the Belle experiment. The main background sources are found to be tau pairs with "tau -> mu nu nu" decay and radiative dimuon…
This PhD thesis studies some hadronic and radiative decays of the tau lepton using a Chiral Lagrangian including resonance fields. After a theoretical introduction, the decays to the $(\pi \pi \pi)^-$, $(KK\pi)^-$ and $\eta^{(\prime)} \pi^-…
The minimal supersymmetric standard model with a low scale see-saw mechanism is presented. Within this framework, the lepton flavour violation in the charged lepton sector is thoroughly studied. Special attention is paid to the individual…
A supersymmetric see-saw model obeying the flavor symmetry L_mu - L_tau, which naturally predicts quasi-degenerate neutrinos, is investigated. Breaking of the symmetry is introduced in the Dirac mass matrix because it is the most economic…
We study two- and three-body lepton flavor violating (LFV) decays involving leptons and neutral vector bosons $V=\rho^0, \omega, \phi, J/\psi, \Upsilon, Z^0$, as well as pseudo-scalar $P=\pi^0, \eta, \eta', \eta_c$ and scalar $S=f_0(500),…
We explore the most general phenomenology of charged lepton flavor violating (CLFV) decays of muon and tau leptons to the three body final states $(\bar{e}ee, \bar{\mu}\mu\mu, \bar{e}\mu\mu, \bar{\mu}\mu e,\bar{\mu}ee, \bar{e}e\mu)$. By…
We study the phenomenology associated with a light bino-like neutralino with mass under the tau mass in the context of the R-parity violating Minimal Supersymmetric Standard Model. This is a well-motivated example of scenarios producing…
In the Standard Model (SM), the rare transitions where a bottom quark decays into a strange quark and a pair of light leptons exhibit a potential sensitivity to physics beyond the SM. In addition, the SM embeds Lepton Flavour Universality…
New heavy leptons with standard model gauge couplings have well determined cross sections for pair production. A standard pattern of mass mixing implies that the most likely decays are $\tau^\prime\to W \nu'$ and $ \nu'\to W \tau$.…
The most general phenomenological model involving a lepton triplet with hypercharge $\pm 1$ is constructed. A distinctive feature of this model is the prediction of a doubly charged lepton, and a new heavy Dirac neutrino. We study the…
The lepton flavour violating signals $e^{+}e^{-}\to \ell^{+}e^{-}$ and $e^{-}e^{-}\to \ell^{-}e^- (\ell=\mu,\tau)$ are studied in the context of low energy R-parity conserving supersymmetry at center of mass energies of interest for the…
We calculate the rates for the charged lepton flavour violating (LFV) decays l_i -> l_j gamma, tau -> l pi, tau -> l eta('), mu^- -> e^-e^+e^-, the six three-body leptonic decays tau^- -> l_i^- l_j^+ l_k^- and the rate for mu-e conversion…
Recently, several indications of lepton non-universality observables have been perceived in semileptonic $B$ meson decay processes, both in the neutral-current ($b \to s ll $) and charged-current ($b \to c l \bar \nu_l$) transitions.…
We study the lepton flavor violation (LFV) in tau decays in the framework of the supersymmetric seesaw mechanism with nonholomorphic terms for the lepton sector at a large $\tan\beta$. In particular, we analyze two new decay modes $\tau\to…
Combining the dark matter and muon $g-2$ anomaly, we study the $U(1)_{L_\mu-L_\tau}$ breaking phase transition, gravitational wave spectra, and the direct detection at the LHC in an extra $U(1)_{L_\mu-L_\tau}$ gauge symmetry extension of…
We study lepton-flavor violation (LFV) effects occurring in the $e-\mu$ conversion in nuclei and in the rare radiative decays $\eta(\eta') \to \gamma \mu e$ of the $\eta$ and $\eta'$ mesons with a special impact of the sub-GeV mass vector…
We report a search for the lepton-flavor-violating decays $\tau^{\pm}\to\ell^{\pm}\alpha$~($\ell=e,\mu$), where $\alpha$ is an undetected spin-0 particle, such as an axion-like particle using $736\times10^{6}$ tau lepton pairs collected by…