Related papers: Improved limits on nuebar emission from mu+ decay
Since the discovery of neutrino oscillations it is known that lepton flavour is not conserved. Lepton flavour violating processes in the charged lepton sector have so far however eluded detection; as they are heavily suppressed in the…
We show that lepton number violating muon decays, \mu^+ -> e^+ + \nu_e-bar + \nu_i-bar (i=e, \mu or \tau), can consistently explain the neutrino anomaly reported by the LSND experiment. Two effective operators in the Standard Model are…
We have searched for lepton flavor violating decays of the tau lepton with one or two KS0 mesons in the final state. The data used in the search were collected with the CLEO II and II.V detectors at the Cornell Electron Storage Ring (CESR)…
We propose an experiment (Mu3e) to search for the lepton flavour violating decay mu+ -> e+e-e+. We aim for an ultimate sensitivity of one in 10^16 mu-decays, four orders of magnitude better than previous searches. This sensitivity is made…
The measurement of the Cabibbo-favored semileptonic decay $\Lambda_c^+\rightarrow \Lambda \mu^+\nu_{\mu}$ is reported using $4.5~\mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data collected at center-of-mass energies ranging from 4.600~GeV to…
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),…
MECO will search for direct evidence of muon and electron flavor violation in the decay of muons in Coulomb bound states via coherent recoil of the nucleus and decay electron. The expected sensitivity to the $\mu^{-} {\rm N} \to e^{-} +…
We present results from a search for the flavor-changing neutral current decays $B\to K\ell^+\ell^-$ and $B\to K^*\ell^+\ell^-$, where $\ell^+\ell^-$ is either an $e^+e^-$ or $\mu^+\mu^-$ pair. The data sample comprises $22.7\times 10^6$…
We present the first direct search for lepton flavour violating muon decay mediated by a new light particle X, $\mu^+ \to \mathrm{e}^+\mathrm{X}, \mathrm{X} \to \gamma\gamma$. This search uses a dataset resulting from $7.5\times 10^{14}$…
We present a search for the decays B0 --> e+e-, B0 --> mu+ mu- and B0 --> e mu using data collected with the BABAR detector at the PEP-II e+e-collider at SLAC. Using a dataset corresponding to 384 x 10^6 BBbar pairs, we do not find evidence…
In this Letter we describe a search for lepton flavor violation (LFV) in the bottomonium system. We search for leptonic decays of Upsilon(nS)(n=1,2, and 3) into muon and tau using the data collected with the CLEO III detector. We identify…
The search for lepton-flavor-violation process e^+e^-\to e\mu in the energy region \sqrt{s}=984 - 1060 MeV with SND detector at VEPP-2M e^+e^- collider is reported. The model independent 90% CL upper limits on the e^+e^-\to e\mu cross…
We have searched for lepton flavor violating decays of the tau lepton with one or two KS0 mesons in the final state. The data used in the search were collected with the CLEO II and II.V detectors at the Cornell Electron Storage Ring (CESR)…
The aim of the work is to study LFV in a newly proposed Seesaw model of neutrino mass and to see whether it could explain LSND excess. The motivation of this Seesaw model was that there was no new physics beyond the TeV scale. By studying…
We present the results of a search for $B^{+}\to\gamma \ell^{+}\nu_{\ell}$, where $\ell = e, \mu$. We use a sample of 232 million $B\bar{B}$ pairs recorded at the $\Upsilon(4S)$ with the BaBar detector at the PEP-II $B$ Factory. We measure…
A search for the lepton number violating $K^{+}\rightarrow\pi^{-}\mu^{+}e^{+}$ and lepton flavour violating $K^{+}\rightarrow\pi^{+}\mu^{-}e^{+}$ decays is reported using NA62 data collected in 2017 and 2018. No significant excess is…
The LHCb collaboration has recently presented their result on R_K = BR(B+ -> K+ mu+ mu-)/ BR(B+ -> K+ e+ e-) for the dilepton invariant mass bin m_{ll}^2 = 1-6 GeV^2 (l = mu, e). The measurement shows an intriguing 2.6 sigma deviation from…
Using a sample of 5.8X10E7 J/$\psi$ events, the Beijing Spectrometer experiment has searched for the decay J/$\psi \to e\mu$. Four candidates, consistent with the estimated background, are observed, and an upper limit on the branching…
In the Standard Model of particle physics, lepton flavour and lepton number are conserved quantities although no fundamental symmetry demands their conservation. I present recent results of searches for lepton flavour and lepton number…
We present the results of a search for the flavor-changing neutral current decay B0_s -> mu+ mu- using a data set with integrated luminosity of 240 pb^{-1} of pp(bar) collisions at sqrt{s}=1.96 TeV collected with the D0 detector in Run II…