相关论文: 2s Hyperfine Structure in Hydrogen Atom and Helium…
A measurement of the hyperfine structure of antihydrogen promises one of the best tests of CPT symmetry. We describe an experiment planned at the Antiproton Decelerator of CERN to measure this quantity in a beam of slow antihydrogen atoms.
The hyperfine structure of atoms and ions is widely used in fundamental and applied research. Accurate knowledge of hyperfine splitting values is essential for quantum metrology applications as well as for improving the performance of…
The quantitative knowledge of heavy nuclei's partonic structure is currently limited to rather large values of momentum fraction $x$ -- robust experimental constraints below $x \sim 10^{-2}$ at low resolution scale $Q^2$ are particularly…
Recent progress in laser and x-ray spectroscopy of muonic atoms offers promising long-term possibilities at the intersection of atomic, nuclear and particle physics. In muonic hydrogen, laser spectroscopy measurements will determine the…
We have measured hyperfine structure in the first-excited $P$ state ($D$ lines) of all the naturally-occurring alkali atoms. We use high-resolution laser spectroscopy to resolve hyperfine transitions, and measure intervals by locking the…
Improved theoretical predictions for the fine-structure splitting of $2^3P_J$ levels in helium are obtained by the calculation of contributions of order $\alpha^5 Ry$. New results for transition frequencies, $\nu_{01} = 29 616 943.01(17)$…
A recent 15 parts-per-million (ppm) experiment on muonic hydrogen found a major discrepancy with QED and independent nuclear size determinations. Here we find a significant discrepancy in a different type of exotic atom, a medium-Z nucleus…
Atomic diffraction through double slits and transmission gratings is well described in terms of the associated de Broglie waves and classical wave optics. However, for weakly bound and relatively large systems, such as the He_2 dimer, this…
This work attempts to present a complete theory of the $\mu$H hyperfine splitting, including all contributions above 1 ppm. Quantum electrodynamic and recoil corrections are calculated directly, while the proton structure correction is…
The ground state hyperfine splitting of positronium $\Delta_{\mathrm{HFS}}$ is sensitive to high order corrections of quantum electrodynamics (QED) in bound state. The theoretical prediction and the averaged experimental value for…
Synthesis of new elements at the upper border of the charts of nuclei and investigation of their decay properties and nuclear structure has been one of the main research topics in low energy nuclear physics since more than five decades.…
There is presently disagreement between theory and experiment as well as between different theoretical calculations concerning the fine-structure splitting of the lowest P state of the neutral helium atom. We believe that we have found a…
In this work, we foresee the structure of a new class of borophenes with smaller 2D densities of atoms than those explored so far for 2D boron crystals. Boron atoms in the porous borophenes tend to be $5$-coordinated in contrast to commonly…
We consider leading $O(m/M)$ nuclear recoil corrections to the hyperfine splitting in light atomic systems. Due to the singularity of hyperfine interactions, the electromagnetic form factors of the nucleus have to be introduced as a…
In order to explain discrepancies between theoretical predictions and experimental data for the helium fine structure, we check and recalculate all theoretical contributions up to orders m\alpha^7 and m^2/M\alpha^6. The previous result for…
By using a Coulomb potential modified by the interaction between the magnetic moments of the electron and proton, we have calculated the energy levels of a hydrogen atom. We have obtained fine structure, hyperfine structure and the Lamb…
A general quantum electrodynamic method for derivation of nuclear recoil corrections in hydrogenic systems, which are exact in the nuclear charge parameter $Z\,\alpha$, is introduced. The exemplary derivation is presented for the $O(m/M)$…
The interaction of hydrogen and metals continues to be industrially relevant and is a critical part of creating and supporting a safety case for nuclear reactor operation. In the present work, we explore hydrogen storage and hydride…
The recent conundrum with the proton charge radius inspires reconsideration of the corrections that enter into determinations of the proton size. We study the two-photon proton-structure corrections, with special consideration of the…
Models play an important role in our understanding of the global structure of the solar wind and its interaction with the interstellar medium. A critical ingredient in many types of models are the charge-exchange collisions between ions and…