The broadening of the three hyperfine EPR nitroxide lines in oxygen supersaturated solutions was examined. The solutions were supersaturated with oxygen either by thermal decomposition of 1,4-peroxy-1,4-dimethylnaphthalene or by pressurizing molecular oxygen above the sample solution. The linear relationship between the Lorentzian component of the line width and the O(2) concentration was prove...

Hyperfine induced 1s2s S0 → 1s 2 S0 M1 transition probabilities of He-like ions have been calculated from relativistic configuration interaction wavefunctions including the frequency independent Breit interaction and QED effects. Present results for Eu and Gd are in good agreement with previous calculations [Phys. Rev. A 63, 054105 (2001)]. Electronic data are given in terms of a general scalin...

We demonstrate that the generalized Gell-Mann–Low theorem permits for a systematic expansion around the nonrelativistic limit when applied to bound states in the Wick-Cutkosky model, Yukawa theory, and QED (in Coulomb gauge). We apply this expansion to obtain new results for the fine and hyperfine structure of bound states in the cases of the Wick-Cutkosky model and Yukawa theory, and reproduce...

As part of a systematic non-proton ENDOR-in-solution study results are reported for 13C in several isotopically enriched model compounds. Methods for synthesizing these labelled compounds are also presented. The optimum 13C ENDOR temperatures are found to be considerably higher than for protons on account of the larger hyperfine anisotropy. Cross relaxation effects are used to determine rotatio...

We have constructed two highly stable and reproducible (87)Rb D(2)-saturated-absorption spectrometers at 780 nm, using dither/third-harmonic lock-in detection and radio-frequency sideband techniques, respectively. We achieved +/-3-kHz reproducibility and agreement between these two independent systems. Heterodyne measurements of the hyperfine splittings of the 5P(3/2) state give its magnetic di...

More nonperturbative corrections to the fine and hyperfine splitting in the heavy quarkonium Abstract The leading nonperturbative effects to the fine and hyperfine splitting were calculated some time ago. Recently, they have been used in order to obtain realistic numerical results for the lower levels in bottomonium systems. We point out that a contribution of the same order O(Λ 4 QCD /m 3 α 2 ...

The muonic helium atom (μe2He) represents the simple three-body atomic system. The interaction between magnetic moments of the muon and electron leads to the hyperfine structure (HFS) of the energy levels. The investigation of the energy spectrum of this atom is important for the check of quantum electrodynamics for three-particle bound state. The ground state hyperfine splitting was measured m...

A simple method of estimating slow-motional rotational correlation times rR for nitroxides by esr, which is based on the rigorous theory of Freed, Bruno, and Polnaszek, is discussed. The results can be fit to the expression r3 = a(1 S)b , where S is the ratio of the separation of the outer hyperfine extrema to that for t,he rigid limit value. The parameters a and b depend upon intrinsic line wi...

Simultaneous measurement of multiple qubits stored in hyperfine levels of trapped 111Cd+ ions is realized with an intensified charge-coupled device (CCD) imager. A general theory of fluorescence detection for hyperfine qubits is presented and applied to experimental data. The use of an imager for photon detection allows for multiple qubit state measurement with detection fidelities of greater t...

We measure the hyperfine splitting of the 9S_{1/2} level of 210Fr, and find a magnetic dipole hyperfine constant A=622.25(36) MHz. The theoretical value, obtained using the relativistic all-order method from the electronic wave function at the nucleus, allows us to extract a nuclear magnetic moment of 4.38(5)micro_{N} for this isotope, which represents a factor of 2 improvement in precision ove...