Related papers: First search for $K^+\to\pi^0\pi\mu e$ decays

The NA62 experiment reports an investigation of the $K^+\rightarrow\pi^+\nu\bar{\nu}$ mode from a sample of $K^+$ decays collected in 2017 at the CERN SPS. The experiment has achieved a single event sensitivity of $(0.389\pm…

The decay $K^+\to\pi^+\nu\bar{\nu}$ is highly suppressed in the Standard Model (SM), while its rate can be predicted with minimal theoretical uncertainty. The branching ratio (BR) for this decay is thus a sensitive probe of the flavor…

Using the CLEO-c detector and a data sample of 0.8 million D+D- pairs at the Psi(3770) a search has been performed for flavor changing neutral current and lepton number violating decays of D+ mesons to final states with dielectrons. No…

A search for the D0 to \pi+ \pi- \mu+ \mu- decay, where the muon pair does not originate from a resonance, is performed using proton-proton collision data corresponding to an integrated luminosity of 1.0 fb-1 recorded by the LHCb experiment…

The KTeV experiment at Fermilab has isolated a total of 132 events from the rare decay KL->e+e-mu+mu-, with an estimated background of 0.8 events. The branching ratio of this mode is determined to be 2.69 +/- 0.24 (stat) +/- 0.12 (syst) x…

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…

We present an update of the search for the lepton family number violating decay $\tau \to \mu\gamma$ using a complete CLEO II data sample of 12.6 million $\tau^+\tau^-$ pairs. No evidence of a signal has been found and the corresponding…

The NA62 experiment at CERN aims to use rare kaon decays to search for new phenomena beyond the Standard Model. During the current short term phase (data taking completed in years 2007-8), the ratio $R_K = \Gamma(K^+ \rightarrow e \nu_e…

We have searched for the Lepton Flavor Violating decay $\tau^- \to \mu^- \eta$ using a data sample of 84.3 fb$^{-1}$ accumulated with the Belle detector at KEK. The $\eta$-meson was detected through the decay modes: $\eta \to \gamma\gamma$…

We search for the lepton-flavor-violating decay of the $J/\psi$ into an electron and a muon using $(225.3\pm2.8)\times 10^{6}$ $J/\psi$ events collected with the BESIII detector at the BEPCII collider. Four candidate events are found in the…

The NA48/2 experiment at CERN reports the first observation of the $K^{\pm} \rightarrow \pi^{0} \pi^{0} \mu^{\pm} \nu$ decay based on a sample of 2437 candidates with 15% background contamination collected in 2003--2004. The decay branching…

Searches for lepton-flavor-violating decay of a tau lepton to a lighter mass lepton and a photon have been performed with the entire dataset of (963 +- 7) x 10^6 tau decays collected by the BaBar detector near the Upsilon(4S), Upsilon(3S)…

Considering the constraints from the experimental data on $\mu\rightarrow e\gamma$, $\mu\rightarrow3e$, $\mu-e$ conversion etc., we analyze the Lepton Flavor Violating decays $\phi(J/\Psi,\Upsilon(1S)) \rightarrow e^+\mu^-(\mu^+\tau^-)$ in…

The lepton flavor violation processes $J/\psi \to \mu\tau$ and $e\tau$ are searched for using a sample of 5.8$\times 10^7$ $J/\psi$ events collected with the BESII detector. Zero and one candidate events, consistent with the estimated…

A search for $B^{0}_{s}\to\tau^{\pm}\mu^{\mp}$ and $B^{0}\to\tau^{\pm}\mu^{\mp}$ decays is performed using data corresponding to an integrated luminosity of 3 fb$^{-1}$ of proton-proton collisions, recorded with the LHCb detector in 2011…

The decay $K^+ \to \pi^+ \nu \bar{\nu}$, with a very precisely predicted branching ratio of less than $10^{-10}$, is one of the best candidates to reveal indirect effects of new physics at the highest mass scales. The NA62 experiment at the…

The first experimental limit on CP violation in pi -> mu -> e decay is extracted from published results of the CERN g-2 experiment.

A search for the nonconservation of lepton flavor number in the decay tau -> mu gamma has been performed using 2.07 x 10^8 e+e- -> tau+ tau- events produced at a center-of-mass energy near 10.58 GeV with the BABAR detector at the PEP-II…

The upcoming Mu3e experiment aims to search for the lepton flavour violating decay $\mu^+ \to e^+ e^- e^+$ with an unprecedented final sensitivity of one signal decay in $10^{16}$ observed muon decays by making use of an innovative…

Recent Kaon decay studies seeking lepton-flavor violating (LFV) new-physics effects are briefly discussed. The main focus is set on precise measurements of rare or not-so-rare decays aiming at finding evidence of deviations from the SM…