Related papers: Increased Sensitivity to Possible Muonium to Antim…
A new experiment has been set up at the Paul Scherrer Institut to search for muonium to antimuonium conversion. No event was found to fulfil the requested signature which consists of the coincident detection of both constituents of the…
A new upper limit for the probability of spontaneous muonium to antimuonium conversion was established at ${\rm P_{M\bar{M}}} \leq 8.2 \cdot 10^{-11}$ (90%C.L.) in 0.1~T magnetic field, which implies consequences for speculative extensions…
A new result from searching for muonium to antimuonium conversion is reported which sets an upper limit on the coupling constant in an assumed $(V-A) \times (V-A)$ type interaction of $G_{M\bar{M}} \leq 3\cdot 10^{-3} G_F$ ~ (90% C.L.). A…
The spontaneous muonium to antimuonium conversion is one of the interesting charged lepton flavor violation processes. It serves as a clear indication of new physics and plays an important role in constraining the parameter space beyond…
We examine the magnetic field dependence of the muonium($\mu^+ e^-$) - antimuonium($\mu^- e^+$) conversion in the models which accommodate the dilepton gauge bosons. The effective Hamiltonian for the conversion due to dileptons turns out to…
The spontaneous conversion of muonium to antimuonium is one of the interesting charged lepton flavor violation phenomena offering a sensitive probe of potential new physics and serving as a tool to constrain the parameter space beyond the…
We study the magnetic field dependence of muonium--antimuonium conversion induced by neutral (pseudo)scalar bosons. Only the $SS$ operator contributes to the conversion of polarized muonium, but it gets quenched by a magnetic field of…
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…
Muonium is a bound state composed of an antimuon and an electron, and it constitutes a hydrogen-like atom. Because of the absence of the hadronic matter in the bound state, the muonium is a useful probe to explore new physics being free…
A low-emittance, high-intensity atomic beam of muonium ($\mathrm{M}=\mu^+ + \mathrm{e}^-$) using superfluid helium as muon-to-muonium converter is being developed at the Paul Scherrer Institute (PSI). This beam could advance laser…
Using a prompt neutrino beam in which a nu_tau component was identified for the first time, the nu_tau magnetic moment was measured based on a search for an anomalous increase in the number of neutrino-electron interactions. One such event…
The muon (g-2) experiment at BNL has completed four data runs for the positive muon, beginning in 1997 and has just finished its first run for the negative muon. Recently the analysis of a 1.3 ppm result based on the 1999 run was completed…
We report muon spin rotation measurements of the local magnetic susceptibility around a positive muon in the paramagnetic state of the quasi one-dimensional spin 1/2 antiferromagnet dichlorobis (pyridine) copper (II). Signals from three…
The magnetic moment anomaly a_mu = (g_mu - 2) / 2 of the positive muon has been measured at the Brookhaven Alternating Gradient Synchrotron with an uncertainty of 0.7 ppm. The new result, based on data taken in 2000, agrees well with…
Our recent series of measurements at Brookhaven National Laboratory determined the muon anomalous magnetic moment \amu to a precision of 0.5 ppm. The final result--representing the average of five running periods using both positive and…
We report muon spin rotation measurements of the local magnetic susceptibility around a positive muon in the paramagnetic state of the quasi one-dimensional spin 1/2 antiferromagnet KCuF$_3$. Signals from two distinct sites are resolved…
Numerous accidental near-degeneracies exist between the $2\nu_2$ and $\nu_4$ rotation-vibration energy levels of ammonia. Transitions between these two states possess significantly enhanced sensitivity to a possible variation of the…
The Mu2e collaboration has proposed an experiment to search for the coherent, neutrino-less conversion of a muon into an electron in the Coulomb field of a nucleus with an expected sensitivity of $R_{\mu e}<6.0\times 10^{-17}$, at the 90%…
The MEG collaboration searches for the mu to e gamma decay at the muon beam line PiE5 of the Paul Scherrer Institut in Switzerland. The world best upper limit has been set to be BR(mu to e gamma) < 5.7 10^-13 at 90% C.L. analyzing a data…
The E821 experiment at Brookhaven National Laboratory is designed to measure the muon magnetic anomaly, a_mu, to an ultimate precision of 0.4 parts per million (ppm). Because theory can predict a_mu to 0.6 ppm, and ongoing efforts aim to…