Muonium-Antimuonium Conversion

The MACS experiment performed at PSI in the 1990s provided an yet unchallenged upper bound on the probability for a spontaneous conversion of the muonium atom, { M=}({\mu^+e^-})M=(μ+e−), into its antiatom, antimuonium {\overline{{M}} = }({\mu^-e^+})M¯=(μ−e+). It comprises the culmination of a series of measurements at various accelerator laboratories worldwide. The experimental limits on the process have provided input and steering for the further development of a variety of theoretical models beyond the standard theory, in particular for models which address lepton number violating processes and matter-antimatter oscillations. Several models beyond the standard theory could be strongly disfavored. There is interest in a new measurement and improved sensitivity could be reached by exploiting the time evolution of the conversion process, e.g., at intense pulsed muonium sources.

Modeling the electron orbital in transition subatomic structure

As part of the well-known task about a motion of charged particle in central forces field, a certain parallelism for electronic distribution between the atomic and subatomic ''orbits'' can be established.In this conjuncture the ground state of muonium atom as in transition electron-nuclear structure is highlighted. Moreover, there is specifically nuclear solution of fine-structure constant which with a hyper-fine structure, like of the Lamb shift of hydrogen atom, is unambiguously associated.Such a special approach, in the terms of electric interaction, may serve as an extension to the existing meson-boson classification.In particular, some idea about a versatility of the Higgs mechanism in nuclear reactions put forward for consideration here.But it would be just spatial abstraction, where subatomic matter expands as into infinity. And what would be beyond the edge of the universe?

High-Precision Microwave Spectroscopy of Muonium for Determination of Muonic Magnetic Moment

The muonium atom is a system suitable for precision measurements for determination of muon’s fundamental properties as well as for the test of quantum electrodynamics (QED). A microwave spectroscopy experiment of this exotic atom is being prepared at J-PARC, jointly operated by KEK and JAEA in Japan, aiming at an improved relative precision at a level of [Formula: see text] in determination of the muonic magnetic moment. A major improvement of statistical uncertainty is expected with the higher muon intensity of the pulsed beam at J-PARC, while reduction of various sources of systematic uncertainties are being studied: those arising from microwave power fluctuations, magnetic field inhomogeneity, muon stopping distribution and atomic collisional shift of resonance frequencies. Experimental strategy and methods are presented in this paper, with an emphasis on our recent development of apparatuses and evaluation of systematic uncertainties.

Solvent-dependent rate constants of muonium atom reactions

The rates of reaction of muonium atoms with solutes, ionic and organic, were studied in solvents of wildly differing polarities (water, methanol, and hexane) and their rate constants were compared, where possible. In these reactions — which are those of a highly reactive atom, an isotope of hydrogen — it transpires that the reaction rates are higher in solvents in which the solute is more soluble and muonium diffuses faster. This study leads to various kinetic-solvent-effect ratios and to the observation of the reaction of muonium with free radicals being among the fastest reactions recorded so far between two neutral species in solution.Key words: muonium atoms, kinetic isotope effects, solvent-dependent rates, non-aqueous solvents, muon spin rotation technique.