Related papers: Higher-Order Nuclear-Size Corrections in Atomic Hy…
Analysis and understanding of the role of hydrogen in metals is a significant challenge for the future of materials science, and this is a clear objective of recent work in the atom probe tomography (APT) community. Isotopic marking by…
We consider hydrogen-like atoms in unstable levels of principal quantum number n=2, confined to a finite size region in a non-homogeneous electric field carrying handedness. The interplay between the internal degrees of freedom of the atoms…
A systematic investigation of the nuclear-polarization effects in one- and few-electron heavy ions is presented. The nuclear-polarization corrections in the zeroth and first orders in $1/Z$ are evaluated to the binding energies, the…
The largest hyperfine interaction coefficients in the hydrogen molecular ion HD$^+$, i.e. the electron-proton and electron-deuteron spin-spin scalar interactions, are calculated with estimated uncertainties slightly below 1~ppm. The…
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…
Corrections of order $\alpha^4$Ry are calculated for the singlet states $1^1S_0$ and $2^1S_0$ of the helium atom. The result for $1^1S_0$ state is in slight disagreement with that of Korobov and Yelkhovsky in [Phys. Rev. Lett. {\bf 87},…
The Coulomb corrections to the helicity amplitudes of high-energy photon splitting are examined. The consideration is based on the amplitudes obtained exactly in the parameter Z\alpha within the quasiclassical approach valid for small…
We present results on the self-energy correction to the energy levels of hydrogen and hydrogenlike ions. The self energy represents the largest QED correction to the relativistic (Dirac-Coulomb) energy of a bound electron. We focus on the…
The Uehling correction to the energy levels is presented in terms of the hypergeometric functions 2F1. This presentation allows to derived various asymptotics and approximations. Further applications of this method to other atomic…
We investigate the gauge invariance of the leading logarithmic radiative correction to the two-photon decay width in hydrogenlike atoms. It is shown that an effective treatment of the correction using a Lamb-shift "potential" leads to…
In this article and beginning with the Dirac solution to the Hydrogen atom in its ground state, the exact results corresponding to the expectation value of the distance of the electron to the proton and the maximum probability distance are…
Two new high-precision measurements of the deuterium abundance from absorbers along the line of sight to the quasar PKS1937--1009 were presented. The absorbers have lower neutral hydrogen column densities (N(HI) $\approx$ 18\,cm$^{-2}$)…
The nuclear quantum effects of hydrogen play a significant role in determining the phase stability of water ice. Hydrogen-bond symmetrization occurs as hydrogen atoms tunnel in a double-well potential, ultimately occupying the midpoint…
The effects of small relativistic corrections to the off-resonant polarizability, hyperpolarizability, and second hyperpolarizability are investigated. Corrections to linear and nonlinear optical coefficients are demonstrated in the…
We calculate ionization energies and fundamental vibrational transitions for H$_2^+$, D$_2^+$, and HD$^+$ molecular ions. The NRQED expansion for the energy in terms of the fine structure constant $\alpha$ is used. Previous calculations of…
We present an analytical calculation of the complete $\alpha^6$ correction to energies of $nP$-levels of two-body systems consisting of the spin-$0$ or $1/2$ extended-size particles with arbitrary masses and magnetic moments. The obtained…
The magic wavelength for an optical lattice for hydrogen atoms that cancels the lowest order AC Stark shift of the 1S-2S transition is calculated to be 513 nm. The magnitude of AC Stark shift $\Delta E=-1.19$ kHz/(10kW/cm$^2$) and the slope…
We reconsider parity violation experiments in atomic hydrogen and deuterium in the light of existing tests of the Electroweak interactions, and assess whether new experiments, using improved experimental techniques, could make useful…
A variational solution procedure is reported for the many-particle no-pair Dirac-Coulomb-Breit Hamiltonian aiming at a parts-per-billion (ppb) convergence of the atomic and molecular energies, described within the fixed nuclei…
The energy interval $ (3S-1S) $ in muonic hydrogen is calculated on the basis of quasipotential approach in quantum electrodynamics. We take into account different corrections of orders $\alpha^3\div \alpha^6 $, which are determined by…