Related papers: The Rare and Forbidden: Testing Physics Beyond the…
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 $\mu^{-} {\rm N} \to e^{-} +…
We review how the muon anomalous magnetic moment ($g-2$) and the quest for lepton flavor violation are intimately correlated. Indeed the decay $\mu \to e \gamma$ is induced by the same amplitude for different choices of in- and outgoing…
The Mu2e experiment searches for the neutrino-less muon to electron conversion in the field of a nucleus, which is a charged lepton flavor violating process. The goal of the experiment is to reach a single event sensitivity of 2.8 x…
The Mu2e experiment aims to test Charge Lepton Flavour Violation to an unprecedented level, enhancing the current sensitivity by four orders of magnitude for the neutrinoless conversion of muons into electrons. A series of graded solenoids…
The muon has been instrumental in establishing the Standard Model of particle physics and continues to play a key role in exploring the nature of New Physics. A global program is underway to enhance the discovery potential of a wide range…
The search for the Lepton Flavor Violating decay mu into e gamma will reach an unprecedented level of sensitivity within the next five years thanks to the MEG-II experiment. This experiment will take data at the Paul Scherrer Institut where…
Some recent precision experiments in low energy muon physics are discussed. Spectroscopy on the muonium atom, the bound state of a positve muon and an electron, has provided precise tests of standard theory and yielded most precise values…
We show that dark photons (A') with masses ~10-80 MeV can be probed in the decay $\mu^+ \to e^+ \nu_e \bar{\nu}_\mu A', A' \to e^+ e^-$, with the upcoming Mu3e experiment at the Paul Scherrer Institute (PSI) in Switzerland. With an expected…
We have designed a new experiment (E923) at the BNL-AGS to search for the T-violating polarization of the muon normal to the decay plane of the KMU3 decay. The experiment aims to search for T-violation beyond the Standard Model; such a…
We present and discuss the development and performance of a compact scintillating fiber (SciFi) detector for timing to be used in the Mu3e experiment at very high particle rates. The SciFi detector is read out with multichannel silicon…
Working within the Standard Model effective field theory approach, we examine the possibility to test charged lepton flavour violating (cLFV) new physics (NP) by angular measurements of the outgoing electron and positrons in the polarised…
In the Standard Model there are several canonical examples of pure leptonic processes involving the muon, the electron and the corresponding neutrinos which are connected by the crossing symmetry: i) the decay of muon, ii) the inverse muon…
Mu3e is an upcoming experiment at Paul Scherrer Institut in the search for the strongly suppressed decay of $\mu\rightarrow eee$. It will use an ultra-lightweight silicon pixel detector using thinned HV-CMOS MAPS chips. Multiple Coulomb…
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…
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 muon is playing a unique role in sub-atomic physics. Studies of muon decay both determine the overall strength and establish the chiral structure of weak interactions, as well as setting extraordinary limits on…
The Mu2e Experiment at Fermilab will search for coherent, neutrino-less conversion of negative muons into electrons in the field of an Aluminum nucleus, $\mu^- + Al \to e^- +Al$. Data collection start is planned for the end of 2021. The…
In the framework of the minimal ${SU}(3)_C\otimes {SU}(3)_L \otimes {U}(1)_N$ model, the lepton-flavour-violating decay $\pi^+ \ra \mu^- \nu_\mu e^+ e^+ $ is calculated without directly invoking lepton mixing. The branching ratio for this…
A next-generation rare pion decay experiment, PIONEER, is strongly motivated by several inconsistencies between Standard Model (SM) predictions and data pointing towards the potential violation of lepton flavor universality. It will probe…
Since its discovery, the muon has proven to be an invaluable probe of the Standard Model (SM). Muons are readily available in tertiary beams in facilities around the world. They do not decay hadronically and have a lifetime of a few $\mu$…