Related papers: Lepton number violating four-body tau lepton decay…

We search for lepton-flavor-violating and lepton-number-violating tau decays into a lepton (l = electron or muon) and two charged mesons (h, h' = pion or Kaon) using 854 fb^{-1} of data collected with the Belle detector at the KEKB…

We study the discovery prospect of different three body lepton number violating~(LNV) meson decays $M_{1}^{-}\to\ell_{1}^{-}\ell_{2}^{-}M_{2}^{+}$ in the framework of right handed~(RH) neutrino extended Standard Model~(SM). We consider a…

In this work the following lepton flavor violating $\tau$ and $\mu$ decays are studied: $\tau^- \to \mu^- \mu^- \mu^+$, $\tau^- \to e^- e^- e^+$, $\mu^- \to e^- e^- e^+$, $\tau^- \to \mu^- \gamma$, $\tau^- \to e^- \gamma$ and $\mu^- \to e^-…

B meson semi-leptonic rare decays are sensitive to new physics beyond standard model. We study the $B^{-}\to \pi^{-}\mu^{+}\mu^{-}$ process and investigate the Majorana neutrino contribution to its decay width. The constraints on the…

A search is performed for the lepton number violating decay $B^{+}\to h^- \mu^+ \mu^+$, where $h^-$ represents a $K^-$ or a $\pi^-$, using data from the LHCb detector corresponding to an integrated luminosity of $36pb^{-1}$. The decay is…

Neutrinoless tau-lepton decays into either three leptons (tau- -> l1- l2 l3) or one lepton and one K0S meson(tau- -> l- K0S) where lepton l means either an electron or muon, have been searched for using 48.6 fb^{-1} of data collected with…

We discuss rare meson decays $K^ + \to \pi ^ - \ell ^ + \ell '^ +$ and $D^ + \to K^ - \ell ^ + \ell '^ +$ ($\ell ,\ell ' = e,\mu $) in a supersymmetric extension of the standard model with explicit breaking of R-parity by bilinear Yukawa…

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…

Based on 7.33 fb$^{-1}$ of $e^+e^-$ collision data collected by the BESIII detector operating at the BEPCII collider at center-of-mass energies from 4.128 to 4.226 GeV, a search for the Majorana neutrino $\nu_m$ is conducted in the…

An observation of any lepton number violating process will undoubtedly point towards the existence of new physics and indirectly to the clear Majorana nature of the exchanged fermion. In this work, we explore the potential of a minimal…

We study the five-body decays $\mu^- \to e^- e^+ e^- \nu_{\mu} \bar{\nu}_{e}$ and $\tau^- \to \ell^- \ell'^+\ell'^-\nu_{\tau}\bar{\nu}_{\ell}$ for $\ell, \ell'=e, \mu$ within the Standard Model (SM) and in a general effective field theory…

The NA48/2 experiment at CERN collected a large sample of charged kaon decays to final states with multiple charged particles in 2003--2004. A new upper limit on the rate of the lepton number violating decay…

We analyse the dependence of the rates of the LFV charged lepton decays mu to e + gamma, tau to e + gamma, tau to mu + gamma (l_i to l_j + gamma) and their ratios, predicted in the class of SUSY theories with see-saw mechanism of nu-mass…

A sensitive search for the lepton-number-violating decay $\Xi^-\to p \mu^-\mu^-$ has been performed using a sample of $\sim10^9$ $\Xi^-$ hyperons produced in 800 GeV/$c$ $p$-Cu collisions. We obtain $\mathcal{B}(\Xi^-\to p \mu^-\mu^-)<…

We discuss rare lepton-number-violating top-quark and W-boson four-body decays to final states containing a same-charge lepton pair, of the same or of different flavors: t -> b W- li^+ lj^+ and W+ -> J J' li^+ lj^+, where i \ne j or i=j and…

Dark particles with lepton-flavor-violating couplings to the tau lepton can induce rare neutrinoless $\tau$ decays with large final state multiplicities. We study models where transitions of the type $\tau^\pm\to \ell^\pm\,\phi$, with…

In this work, we study the lepton number violating tau decays via intermediate on-shell Majorana neutrinos $N_j$ into two scalar mesons and a lepton $\tau^{\pm} \to M_1{}^{\pm} N_j \to M_1^{\pm} M_2^{\pm} \ell^{\mp}$. We calculate the…

Lepton number violation processes can be induced by the Majorana neutrino exchange, which provide evidence for the Majorana nature of neutrinos. In addition to the natural explanation of the small neutrino masses, Type-I seesaw mechanism…

The lepton number violating process, $e^- e^- \to W^- W^-$ has been widely discussed in the Majorana neutrino exchange mechanism. Here, we discuss this process in a composite neutrino model where excited Majorana neutrinos are exchanged. We…

A search for the neutrinoless, lepton-flavor violating decay of the tau lepton into three charged leptons has been performed using 376 fb^{-1} of data collected at an e^+e^- center-of-mass energy around 10.58 GeV with the BaBar detector at…