Related papers: Isotope dependence of muon-to-electron conversion
We discuss predictions for the lepton-flavour changing decays Z --> e mu, mu tau, e tau which may be searched for at the Giga-Z option of the Tesla Linear Collider project with Z resonance production rates as high as 10^9. We try to be as…
The Mu2e experiment at Fermilab will search for the charged lepton flavour violating process of coherent neutrinoless muon-to-electron conversion in the presence of an aluminum nucleus. The muons are produced by an 8 GeV proton beam from…
We estimate sensitivity coefficients Q_\mu to variation of the electron-to-proton mass ratio \mu for microwave transitions in partly deuterated ammonia NH2D and ND2H. Because of the mixing between rotational and inversion degrees of freedom…
Study of the fusion reactions between hydrogen isotopes in muonic molecules is the first example of the accurate accounting of the nucleus charge screening by a muon in the fusion process. At LUNA installation the measurements of…
The most sensitive experiment to date to search for the muon and electron lepton number violating decay $K^0_L \to \mu^\pm e^\mp$ has detected no events consistent with this process. Based on this result, the 90% confidence level upper…
The production of $\tau\mu$ pairs in electron-positron collisions offers a powerful probe of lepton flavor violation. In this work, we calculate the $e^+ e^- \to \tau \mu$ cross section within the framework of the Standard Model Effective…
We discuss proton and neutron decays involving three leptons in the final state. Some of these modes could constitute the dominant decay channel because they conserve lepton-flavor symmetries that are broken in all usually considered…
We consider charged lepton flavor violating transitions mediated by the diphoton effective interactions $\ell_i\ell_j\gamma\gamma$ and explore which processes can probe them better. Our analysis includes single and double radiative decays,…
The new round of experiments, MEG II, COMET/Mu2e, and Mu3e, would soon start to push the $\mu \to e\gamma$, $\mu N \to eN$ conversion, and $\mu \to 3e$ frontier, while Belle II would probe $\tau \to \mu\gamma$ and $\tau \to 3\mu$. In the…
The coherent and incoherent channels of the neutrinoless muon to electron conversion in nuclei, $\mu^- (A,Z) \to e^- (A,Z)^*$, are studied throughout the periodic table. The relevant nuclear matrix elements are computed by explicitly…
We investigate the ability of $\mu\rightarrow e$ facilities, Mu2e and COMET, to probe, or discover, new physics with their detector validation datasets. The validation of the detector response may be performed using a dedicated run with…
The intense muon beams which will be available at a neutrino factory provide a unique opportunity for searching for physics beyond the standard model, both in lepton flavor violation and in the search for a permanent electric dipole moment…
One of the key assumptions of the Standard Model of fundamental particles is that the interactions of the charged leptons, namely electrons, muons, and taus, differ only because of their different masses. While precision tests comparing…
Newly calculated bounds on the strength of the coupling of an electron to a proton or a neutron by a fifth force are presented. These results are derived from the high precision spectroscopic data currently available for hydrogen,…
Minimal extensions of the Standard Model that are motivated by grand unified theories or superstring models with an E_6 symmetry can naturally predict heavy neutrinos of Dirac or Majorana nature. Such heavy neutral leptons violate the de-…
The electric and magnetic dipole moments of the electron and of the muon provide stringent tests of the Standard Model and sensitive probes of new physics. By contrast, the corresponding dipole moments of the $\tau$ lepton remain weakly…
In many models of CP violation, the electric dipole moments (EDMs) of leptons scale as the cube of the lepton mass. In these models, the EDM of a 100 GeV heavy lepton would be a billion times greater than that of the muon, and could be as…
The J-PARC muon $g - 2$/EDM experiment aims to measure the muon magnetic moment anomaly $a_{\mu} = (g -2) / 2 ~ $ and the muon electric dipole moment (EDM) $d_{\mu}$. The target sensitivity for $a_{\mu}$ is a statistical uncertainty of $450…
The transition magnetic moment between active and sterile neutrinos is theoretically well-motivated scenario beyond the Standard Model, which can be probed in cosmology, astrophysics, and at terrestrial experiments. In this work, we focus…
Vibrational overtones in deeply bound molecules are sensitive probes for variation of the proton-to-electron mass ratio $\mu$. In nonpolar molecules, these overtones may be driven as two-photon transitions. Here, we present procedures for…