[en] Recent theoretical and experimental studies of the exotic atoms with Z = 1 are reviewed. An interplay between the atomic internal and external degrees of freedom is essential for a good description of the atomic cascade. The perspective of ab initio cascade calculations is outlined

[en] The contribution of hadronic vacuum polarization to the energy levels of muonic atoms is reevaluated using an improved parametrization of the total cross section for e⁺e^- → hadrons. The numerical results can be simply related to the correction due to muonic vacuum polarization. (orig.)

[en] A polarization shift of the levels and a corresponding polarization potential has been found for muonic atoms with Zapprox.10--50, for which the Coulomb energy of the muon is on the order of or greater than the characteristic excitation energy of the nucleus

No abstract available

[en] An understanding of the experimental muon spin rotation technique is provided. The temperature dependence of the μ-hyperfine coupling constants for muonic radicals formed in [²H₁] ethene and [²H₃] ethene and [²H₄] ethene is analysed and compared to the ones for the corresponding protonic species. The barrier height restricting internal rotation is also studied for the same range of radicals. Finally, the family of ions and radicals of the type RXY (R=H,Mu; X,Y=C,O,N) is discussed with regard to their vibrational frequencies which provide a measure of the extent of the large amplitude vibrations for the muonic species

[en] The conditions for the formation of pion-hydrogen atom are briefly summarized. The measuring apparatus is described in detail. The experimental results of the pion capture in various mixtures of gases are compared to the theoretical predictions. The influence of the chemical structure on the pion capture probability in various hydrogen compounds is analyzed. (P.L.)

[en] Two projects of the experimental study of nuclear reactions between light nuclei (p, d, t, He, Li, Be) in the region of very low energies are presented. The first proposal deals with nuclear fusion reactions in charge-nonsymmetric muonic molecular complexes such as ^3,4He dμ, ^3,4He tμ, ^6,7Li pμ, ^6,7Li tμ. In the second one we consider a new approach to the measurement of nuclear reaction cross sections of light nuclei (p, d, t) in the range of 0.01-2 keV, using high intensity radially converging ion flow generated during linear implosion in plasma with the use of high power pulsed generator. The choice of experimental conditions has been made and lower limits of the measured values (fusion rates and cross sections) have been estimated. (author). 23 refs, 5 figs, 1 tab

[en] Experimental research is summarized on nuclear energy levels including pionic and muonic x rays. A list of publications is included

No abstract available

[en] It is shown that the 1S level hyperfine populations prior to muon capture will be statistical when either target or beam is unpolarized independent of the atomic level at which the hyperfine interaction becomes appreciable. This assertion holds in the absence of magnetic transitions during the cascade and is true because of minimal polarization after atomic capture and selective feeding during the cascade