Related papers: Background Suppression for $\mu\to e\gamma$ with P…
The existence of a new, photon-like, massive particle, the gamma' or dark photon, is postulated in several extensions of the Standard Model. These models are often advocated to explain some recent puzzling astrophysical observations, as…
We consider massive Dirac electron antineutrino to be observed in the muon decay, $\mu^{-} \rightarrow e^- +\bar{\nu}_{e} + \nu_{\mu}$, at rest in the LAB reference frame. A computation of $\bar{\nu}_{e}$ differential direct spectral shape…
We propose the $\mu^-\to e^-\gamma$ process in a muonic atom as a novel means to investigate charged lepton flavor violation (CLFV). We demonstrate its sensitivity in probing effective CLFV operators associated with both single and double…
We calculate the decay of $\tau^-\to\pi^-\gamma\nu_\tau$ in the framework of Resonance Chiral Theory ($R\chi T$). By demanding the high energy constraints from QCD on the related form factors, we could predict the various physical…
The Mu2e experiment will search for a Standard Model violating rate of neutrinoless conversion of a muon into an electron in the presence of an aluminum nucleus. Observation of this charged lepton flavor violating process would be an…
We explore the possibility of probing flavor violations in the charged-lepton sector by means of high-luminosity lepton-photon and electron-muon collisions, by inverting initial and final states in a variety of decay channels presently used…
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 spectrum of very fast electrons in five-lepton decay $\mu^+\to e^-e^+e^+\nu\bar\nu,$ that is the main background decay at the study of the muonium-antimuonium conversion in vacuum, is considered. The essential decrease of the spectral…
It is well known that at linear e^+e^-(e^-e^-) colliders using laser backscattering one can obtain colliding gamma-gamma, gamma-electron beams with energy and luminosity comparable to those in e^+e^- collisions. In this paper, it is…
Radiative muon decay in the kinematics similar to the neutrinoless decay $\mu\to e\gamma$ is considered. Radiative corrections due to 1-loop virtual photons and emission of additional soft or hard photons are taken into account. Analytical…
The upcoming Mu3e experiment searches for the lepton flavour violating decay $\mu^+\,\rightarrow\,e^+ e^- e^+$ with the aim of a final sensitivity of one signal decay in $10^{16}$ observed muon decays, an improvement over the preceding…
A nonconventional $U(1)_{e-\mu}$ gauge model is proposed to explain the unexpected anomalous magnetic moments of the electron and muon (lepton $g-2$), where only the right-handed electron and muon in the standard model carry the…
The final results of the search for the lepton flavour violating decay $\mu^{+} \rightarrow {\rm e^{+}} \gamma$ based on the full dataset collected by the MEG experiment at the Paul Scherrer Institut in the period 2009--2013 and totalling…
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 $SU(2)_L$…
The observation of lepton flavour violation (LFV) in the charged lepton sector would be an unambiguous sign of physics beyond the Standard Model (BSM), and thus, it is the channel of choice for many BSM searches. LFV searches in muon decays…
Starting from the new sources of $LL$- and $LR$- scalar (slepton) mixings due to R-parity violation, we discuss the structure of lepton-flavor violation focusing on the radiative decay of muon into electron. Using an optimal…
We study the possibility of discovering resonances in $\mu^+e^- \to \mu^- e^+$ and $e^-e^- \to \mu^- \mu^-$ collisions. We begin with the closely related problem of muonium--antimuonium transitions, where the experimental limit has just…
We calculate the rate of the decay $\mu \to e\gamma$ and the electric dipole moment of the electron in the left-right supersymmetric model when the breaking of parity occurs at a considerably large scale. The low-energy flavor violation in…
The standard model (SM) of particle physics is spectacularly successful, yet the measured value of the muon anomalous magnetic moment $(g-2)_\mu$ deviates from SM calculations by 3.6$\sigma$. Several theoretical models attribute this to the…
Damping of an electromagnetic wave in a strong magnetic field is analyzed in the kinematic region near the threshold of electron-positron pair production. Damping of the electromagnetic field is shown to be noticeably nonexponential in this…