The current status of the determination of corrections to the hyperfine splitting of the ground state in hydrogen is considered. Improved calculations are provided taking into account the most recent value for the proton charge radius. Comparing experimental data with predictions for the hyperfine splitting, the Zemach radius of the proton is deduced to be 1.045(16) fm. Employing exponential pa...

We present a measurement of the hyperfine splitting of the 6S1/2 excited level of rubidium using two-photon absorption spectroscopy in a glass cell. The values we obtain for the magnetic dipole constant A are 239.18 03 MHz and 807.66 08 MHz for Rb and Rb, respectively. The combination of the magnetic moments of the two isotopes and our measurements show a hyperfine anomaly in this atomic excite...

Electron nuclear double resonance signals of the pyrrole nitrogens of bacteriochlorophyll alpha cation in a solution of CH2Cl2/CH3OH (6:1) have been observed. The nitrogens are inequivalent: the hyperfine coupling constants were determined to be 2.36 and 3.18 MHz (0.84 and 1.14 G, respectively). Triple electron nuclear double resonance experiments have yielded the signs and values of nine proto...

The electron paramagnetic resonance (EPR) parameters (g factors and the hyperfine structure constants) for Ni2+ and Co+ in MgO are theoretically studied from the perturbation formulas of these parameters for a 3d8 ion in octahedral crystal-fields. In the computations, the ligand orbital and spin-orbit coupling contributions are taken into account using the cluster approach. The calculated EPR p...

A theoretical model of hyperfine spectra of nuclear spin conversion of molecular isomers has been developed. The model takes into account the nuclear spin-spin and spin-rotation interactions, as well as the saturation of intramolecular mixing of molecular ortho and para states. The model has been applied to hyperfine spectra of nuclear spin conversion in CH3F molecules subjected to an external ...

The 4d S0 ground-state transitions to the 4d 9 5p configuration of palladium (Pd) have been studied. For this purpose, a tunable, single-mode, deep-UV cw laser has been built to generate the sum frequency of a frequency-doubled Ti:S laser with a second Ti:S laser. The produced wavelengths range from 244 to 276 nm. From the measured spectra the frequency splitting due to hyperfine structure and ...

We observe a hyperfine anomaly in the measurement of the hyperfine splitting of the 6S1/2 excited level in rubidium. We perform two step spectroscopy using the 5S1/2 → 5P1/2 → 6S1/2 excitation sequence. We measure the splitting of the 6S1/2 level and obtain for the magnetic dipole constants of Rb and Rb A = 239.18(4) MHz and A = 807.66(8) MHz, respectively. The hyperfine anomaly difference of 8...

We produce ultracold dense trapped samples of ^{87}Rb^{133}Cs molecules in their rovibrational ground state, with full nuclear hyperfine state control, by stimulated Raman adiabatic passage (STIRAP) with efficiencies of 90%. We observe the onset of hyperfine-changing collisions when the magnetic field is ramped so that the molecules are no longer in the hyperfine ground state. A strong quadrati...

A paramagnetic muonium (Mu) state with an extremely small hyperfine parameter was observed for the first time in single-crystalline GaN below 25 K. It has a highly anisotropic hyperfine structure with axial symmetry along the <0001> direction, suggesting that it is located either at a nitrogen-antibonding or a bond-centered site oriented parallel to the c axis. Its small ionization energy (<or=...

Magnetic hyperfine fields for Se on Ni(111) and Ni(001) surfaces were measured with the perturbed angular correlation technique. The results are jBhfj ­ 2.7s3d T for Se on Ni(111) and jBhfj ­ 0.8s3d T for Se on Ni(001) at 90 K. These values of magnetic hyperfine fields of an adatom deviate drastically from the known bulk value of Bhf ­ 15 T. The surface site positions of the probe atoms are dis...