Related papers: Bounds on majoron emission from muon to electron c…
The experimental discovery of large nu_mu-nu_tau mixing indicates that analogous mixing in the charged lepton sector could be substantial. We consider the possibility that if a high intensity muon beam, perhaps at the early stages of a muon…
We investigate a possibility that the $\mu^-\to e^+$ conversion is discovered prior to the $\mu^-\to e^-$ conversion, and its implications to the new physics search. We focus on the specific model including the mixing of the $SU(2)_L$…
Muons decay in vacuum mainly via the leptonic channel to an electron, a muon neutrino and an electron antineutrino. Previous investigations have concluded that muon decay can only be significantly altered in a strong electromagnetic field…
A search is presented for a Higgs-like boson with mass in the range 45 to 195 GeV/$c^2$ decaying into a muon and a tau lepton. The dataset consists of proton-proton interactions at a centre-of-mass energy of 8 TeV, collected by the LHCb…
We consider the process of muon-electron elastic scattering, which has been proposed as an ideal framework to measure the running of the electromagnetic coupling constant at space-like momenta and determine the leading-order hadronic…
Muon lepton flavor processes are reviewed in connection with search for physics beyond the standard model. Several methods to distinguish different theoretical models are discussed for $\mu \to e \gamma$, $\mu \to 3 e$, and $\mu - e$…
We study the response of the electron mass to an externally applied electrical field. As a consequence of nonlinear electromagnetic (EM) effective action, the mass of a particle diminishes in the presence of an externally applied electric…
We study the rare decays of charged \pi\ mesons, \pi+ to e+ e+ \mu- anti-\nu_\mu\ and \pi+ to e+ \mu- e+ \nu_e, induced by a sterile neutrino N with a mass in the range m_\mu < m_N < m_\pi. The first process violates Lepton Number by two…
Recent Standard Model predictions for the anomalous magnetic moments of the electron, muon and tau lepton are reviewed and compared to the latest experimental values.
At muon colliders, muon decays naturally produce intense electrons and positrons with unique features, namely high energies, high repetition rates, and small intrinsic uncertainties, that are unavailable at existing accelerator facilities.…
We estimate the numbers and mass spectra of observed lepton and kaon pairs produced from $\phi$ meson decays in the central rapidity region of an Au+Au collision at lab energy 11.6 GeV/nucleon. The following effects are considered: possible…
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…
MiniBooNE seeks to confirm or refute the LSND muon-antineutrino to electron-antineutrino oscillation signal with high statistical significance and different systematics. MiniBooNE has accumulated the world's largest GeV neutrino data set.…
We present an estimate of the electron to muon conversion cross section in fixed-target elastic electron scattering. The matrix element $<\mu | j_\mathrm{em}^\mu(0) | e>$ is calculated analytically in two scenarios introducing suitable…
We have performed a global analysis of muon decay measurements to establish model-independent limits on the space-time structure of the muon decay matrix element. We find limits on the scalar, vector and tensor coupling of right- and…
We discuss limits on neutrino-Majoron couplings both from laboratory experiments as well as from astrophysics. They apply to the simplest class of Majoron models which covers a variety of possibilities where neutrinos acquire mass either…
A confirmation of the long-standing muon $g$-2 discrepancy requires both experimental and theoretical progress. On the theory side, the hadronic corrections are under close scrutiny, as they induce the leading uncertainty of the Standard…
The majoron, a pseudo-Goldstone boson arising from the spontaneous breaking of global lepton number, is a generic feature of many models intended to explain the origin of the small neutrino masses. In this work, we investigate potential…
We summarize recent work to develop an effective theory of muon-to-electron conversion, based on a complete set of low-energy effective operators that are developed from a systematic expansion in velocities and momenta. The expansion…
The leptons are viewed as composite objects, exhibiting anomalous magnetic moments and anomalous flavor-changing transition moments. The decay $\mu \to e \gamma$ is expected to occur with a branching ratio of the same order as the present…